JP2004092600A

JP2004092600A - Cogeneration system

Info

Publication number: JP2004092600A
Application number: JP2002258066A
Authority: JP
Inventors: Masayuki Ushio; 牛尾　雅之; Tetsuji Morita; 森田　哲司; Seiji Omori; 大森　誠児; Yuko Kimura; 木村　祐子; Yuichi Murase; 村瀬　裕一
Original assignee: Osaka Gas Co Ltd
Current assignee: Osaka Gas Co Ltd
Priority date: 2002-09-03
Filing date: 2002-09-03
Publication date: 2004-03-25
Anticipated expiration: 2022-09-03
Also published as: JP4267277B2

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately supply hot water to each of dwelling units even when exhaust heat can not be supplied from a power generation means, and the exhaust heat of the power generation means is insufficient for hot water to be heated, and even at non-power generation time zone, and to equally supply the hot water to the utmost to the plurality of dwelling units including units different in a time zone of using hot water, at a low cost. <P>SOLUTION: This cogeneration system comprises: the power generation means 1; a heat exchanger 2 for exhaust heat recovery supplied with an exhaust heat from the power generation means 1; a hot water storage tank 3 for storing the hot water with the plurality of dwelling units H as a hot water supply subject; a water feeding means W1 for tank which feeds water to the hot water storage tank 3; a circulation means C1 for exhaust heat recovery which circulates the hot water over the heat exchanger 2 for exhaust heat recovery and the hot water storage tank 3; and a hot water circulation means C2 for circulating the hot water through a hot water circulation passage R arranged from the hot water storage tank 3 to the plurality of dwelling units H. In the cogeneration system, an auxiliary heating means B2 for heating the hot water flowing in the hot water circulation passage R is provided. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、地域又は集合住宅を電力供給対象として発電する発電手段、その発電手段からの排熱が供給される排熱回収用熱交換器、前記地域又は集合住宅に含まれる複数の住戸を給湯対象として湯水を貯留する貯湯槽、その貯湯槽に給水する槽用給水手段、前記排熱回収用熱交換器と前記貯湯槽とにわたって湯水を循環させる排熱回収用循環手段、及び、前記貯湯槽と前記複数の住戸とにわたる給湯用循環経路にて湯水を循環させる給湯用循環手段が設けられたコージェネレーションシステムに関する。
【０００２】
【従来の技術】
かかるコージェネレーションシステムは、発電手段の運転中にその発電手段から発生する排熱により、貯湯槽の湯水を加熱し、その貯湯槽の湯水を給湯用循環経路を通じて循環させるものであり、各住戸においては、給湯用循環経路を循環する湯水を用いて、風呂や台所等に給湯することができるようになっている。
ちなみに、１日のうちの一部の時間帯として設定される設定発電時間帯においては発電手段を作動させ、その設定発電時間帯以外の非発電時間帯においては発電手段を停止させる形態で運転する場合がある。その場合、その設定発電時間帯は、通常、地域又は集合住宅に含まれる複数の住戸全体としての電力需要の多い時間帯、例えば、１８時から２４時までの時間帯に設定される。
【０００３】
かかるコージェネレーションシステムにおいては、従来、図１１に示すように、貯湯槽３と複数の住戸とにわたる給湯用循環経路８４を循環する貯湯槽３の湯水が、単に、発電手段の排熱のみにより加熱されるように構成したものが開示されている（例えば、特許文献１参照）。
上記従来のコージェネレーションシステムでは、図１１に示すように、貯湯槽３を密閉式に構成し、槽用給水手段Ｗ１を、水道からの水を貯湯槽３の底部に供給する給水路８１にて構成し、排熱回収用循環手段Ｃ１を、貯湯槽３と排熱回収用熱交換器２とにわたる循環経路を形成する排熱回収用流路８２と、その排熱回収用流路８２に設けた排熱回収用循環ポンプ８３とから構成し、給湯用循環手段Ｃ２は、前記給湯用循環経路８４と、その給湯用循環経路８４に設けた給湯用循環ポンプ８５とから構成していた。尚、図１１中において、Ｋは、給湯用循環手段Ｃ２にて供給される湯水を加熱すべく、各住戸に設けられた給湯器である。
【０００４】
【特許文献１】
特開平７−３２４８０９号公報
【０００５】
【発明が解決しようとする課題】
ところで、かかるコージェネレーションシステムにおいては、発電手段のメンテナンスを行ったり、発電手段が故障したりするときがあるが、そのようなときには、発電手段から排熱を供給することができなくなる。
しかしながら、従来では、給湯用循環経路を循環する貯湯槽の湯水を、単に、発電手段の排熱のみにより加熱するので、発電手段のメンテナンスや故障のときに、発電手段からの排熱供給が不可能になると、各住戸に適切に給湯できなくなるという問題があった。
又、複数の住戸での湯の使用量が多いときや、発電手段の起動時、部分負荷運転時等、加熱対象の湯水に対して発電手段からの排熱が不足するときは、貯湯槽の湯水の温度が低下して、各住戸に適切に給湯できなくなり、同様に、１日のうちの一部の時間帯である設定発電時間帯において発電手段を作動させる形態で運転する場合は、非発電時間帯においては、発電手段から排熱を供給することができないので、貯湯槽の湯水の温度が設定発電時間帯に比べてかなり低くなり、各住戸に適切に給湯できなくなるという問題があった。
そして、複数の住戸には、湯の使用時間帯が異なる種々の生活パターンの住戸が含まれるものであり、湯の使用時間帯は各住戸で異なるものであるが、前述のように、貯湯槽の湯水の温度が時間帯によって変化すると、貯湯槽の湯水の温度が低い時間帯に湯の使用量の多い住戸と、貯湯槽の温度が高い時間帯に湯の使用量の多い住戸とが生じることになり、複数の住戸に対して極力平等に給湯することができない問題を招くものとなる。
【０００６】
本発明は、かかる実情に鑑みてなされたものであり、その目的は、発電手段からの排熱供給が不可能なときや、加熱対象の湯水に対して発電手段の排熱が不足するとき、及び、非発電時間帯にも、各住戸に適切に給湯できるものとなって、湯の使用時間帯が異なる住戸が含まれる複数の住戸に対して極力平等に給湯でき、しかも、低廉化を図ることができるコージェネレーションシステムを提供することにある。
【０００７】
【課題を解決するための手段】
〔請求項１記載の発明〕
請求項１に記載のコージェネレーションシステムは、地域又は集合住宅を電力供給対象として発電する発電手段、その発電手段からの排熱が供給される排熱回収用熱交換器、前記地域又は集合住宅に含まれる複数の住戸を給湯対象として湯水を貯留する貯湯槽、その貯湯槽に給水する槽用給水手段、前記排熱回収用熱交換器と前記貯湯槽とにわたって湯水を循環させる排熱回収用循環手段、及び、前記貯湯槽と前記複数の住戸とにわたる給湯用循環経路にて湯水を循環させる給湯用循環手段が設けられたものであって、
前記給湯用循環経路を通流する湯水を加熱する補助加熱手段が設けられている点を特徴構成とする。
即ち、補助加熱手段により、給湯用循環経路を通流する湯水を加熱することができる。
つまり、発電手段のメンテナンスや故障のときに、発電手段からの排熱供給が不可能になって、発電手段からの排熱による貯湯槽の湯水の加熱ができなくなったり、加熱対象の湯水に対して発電手段からの排熱が不足して、貯湯槽の湯水の温度が低下したりするときは、補助加熱手段にて、給湯用循環経路を通流する湯水を加熱することにより、各住戸に適切に給湯することができ、又、１日のうちの一部の時間帯である設定発電時間帯において発電手段を作動させる形態で運転する場合は、非発電時間帯において貯湯槽の湯水の温度が低くなっても、補助加熱手段にて、給湯用循環経路を通流する湯水を加熱することにより、各住戸に適切に給湯することができる。
しかも、給湯用循環経路にて住戸に供給される湯水を補助加熱手段にて加熱するに当たり、補助加熱手段にて給湯用循環経路を通流する湯水を加熱するようにしているから、給湯用循環経路にて住戸に供給される湯水を補助加熱手段にて加熱するための構成を簡素化することが可能となる。
説明を加えると、補助加熱手段にて給湯用循環経路を通流する湯水を加熱するようにするようにすることにより、給湯用循環経路を通じて湯水を循環させるように、本来備えられている湯水循環機能を利用して、湯水を補助加熱手段に通流させるようにすることが可能となり、構成の簡素化を図ることが可能となる。
ちなみに、給湯用循環経路にて住戸に供給される湯水を補助加熱手段にて加熱するに当たり、補助加熱手段にて貯湯槽の湯水を加熱するようにすることが考えられるが、この場合は、補助加熱手段に湯水を通流させるための流路を貯湯槽に対して接続すると共に、その流路にポンプを設ける必要があり、構成が複雑化する。
ちなみに、補助加熱手段を、給湯用循環経路における各住戸を経由する箇所よりも上流側にて湯水を加熱するように設けると、速やかに各住戸に昇温した湯水を供給できるので、より好ましい。
尚、ガス加熱式の湯沸し器等を用いて構成される補助加熱手段の設置コストやランニングコストは、複数の住戸で分担されるものであるから、補助加熱手段の使用により各住戸に不平等を与えることがないことは当然である。
従って、発電手段からの排熱供給が不可能なときや、加熱対象の湯水に対して発電手段の排熱が不足するとき、及び、非発電時間帯にも、各住戸に適切に給湯できるものとなって、湯の使用時間帯が異なる住戸が含まれる複数の住戸に対して極力平等に給湯できるものであり、しかも、補助加熱手段にて湯水を加熱するための構成の簡素化により低廉化を図ることができるコージェネレーションシステムを得るに至った。
【０００８】
〔請求項２記載の発明〕
請求項２に記載のコージェネレーションシステムは、請求項１において、運転を制御する運転制御手段が、１日のうちの一部の時間帯として設定される設定発電時間帯においては前記発電手段、前記排熱回収用循環手段及び前記給湯用循環手段を作動させ、その設定発電時間帯以外の非発電時間帯においては前記発電手段及び前記排熱回収用循環手段を停止させ且つ前記給湯用循環手段を作動させる形態で、且つ、
前記設定発電時間帯及び前記非発電時間帯においては、前記給湯用循環経路を通流する湯水を目標加熱温度に加熱するように前記補助加熱手段を加熱作動させる形態で運転を制御するように構成されている点を特徴構成とする。
即ち、１日のうちの一部の時間帯として設定される設定発電時間帯においては発電手段、排熱回収用循環手段及び給湯用循環手段が作動され、その設定発電時間帯以外の非発電時間帯においては発電手段及び排熱回収用循環手段が停止され且つ給湯用循環手段が作動され、並びに、設定発電時間帯及び非発電時間帯においては、補助加熱手段により、給湯用循環経路を通流する湯水が目標加熱温度に加熱される。
つまり、設定発電時間帯においては、発電手段の排熱にて貯湯槽の湯水が加熱される状態で、貯湯槽の湯水が給湯用循環経路に循環され、非発電時間帯においては、発電手段からの排熱が無いので、発電手段の排熱による貯湯槽の湯水の加熱が停止される状態で、貯湯槽の湯水が給湯用循環経路に循環され、設定発電時間帯と非発電時間帯とを通じて、補助加熱手段により、給湯用循環経路を通流する湯水が目標加熱温度に加熱される。
従って、発電手段が１日のうちの一部の設定発電時間帯で運転される場合において、時間帯に係わらず、各住戸に安定した温度にて給湯することができる。
【０００９】
〔請求項３記載の発明〕
請求項３に記載のコージェネレーションシステムは、請求項２において、前記複数の住戸のそれぞれに給水する住戸用給水手段が設けられ、
前記複数の住戸のそれぞれに、前記給湯用循環手段を通じて供給される湯水と前記住戸用給水手段を通じて供給される水とを混合する混合部、及び、その混合部から供給される湯水を加熱する加熱部を備えて、湯水需要部に給湯する給湯器が設けられ、
その給湯器は、前記湯水の温度が給湯目標温度よりも設定温度差以上低いときは、前記給湯目標温度よりも前記設定温度差以上低くなるように設定された設定混合温度になるように前記混合部の混合作動を制御し、且つ、給湯温度が前記給湯目標温度になるように前記加熱部の加熱作動を制御し、前記湯水の温度が前記給湯目標温度に対して前記設定温度差低い温度よりも高いときは、前記加熱部の加熱作動を停止させた状態で、給湯温度が前記給湯目標温度になるように前記混合部の混合作動を制御するように構成され、
前記目標加熱温度として、前記給湯器における前記給湯目標温度の設定範囲外の温度に設定されている点を特徴構成とする。
即ち、各住戸の給湯器においては、給湯用循環経路からの湯水の温度が給湯目標温度よりも設定温度差以上低いときは、一旦、給湯目標温度よりも設定温度差以上低くなるように設定された設定混合温度になるように、給湯用循環手段を通じて供給される湯水に住戸用給水手段からの水が混合されてから、給湯温度が給湯目標温度になるように加熱され、一方、給湯用循環経路からの湯水の温度が給湯目標温度に対して設定温度差低い温度よりも高いときは、加熱が停止されて、給湯温度が給湯目標温度になるように、給湯用循環手段を通じて供給される湯水に住戸用給水手段からの水が混合されることになり、もって、給湯目標温度にて給湯することができる。
つまり、給湯用循環経路からの湯水の温度と給湯目標温度との温度差が小さくて、目標温度に加熱するための加熱量が予め設定された設定最小加熱量よりも小さいときは、給湯目標温度に加熱し難いので、一旦、混合部にて水を混合して設定混合温度にまで下げてから、加熱部にて給湯目標温度に加熱することにより、給湯温度を安定化させ、一方、給湯用循環経路からの湯水の温度が給湯目標温度に対して設定温度差低い温度よりも高いときは、加熱部による加熱を停止して、混合部にて給湯目標温度になるように水を混合することにより、加熱部を加熱作動させる形態で運転される時間を減らすようにして省エネを図りながら、給湯温度を安定化させている。
つまり、各住戸においては、給湯目標温度が様々に設定されることになるので、給湯用循環手段を通じて供給される湯水を用いて、各住戸において給湯目標温度にて給湯するようにするには、上述のような構成の給湯器を設置することになる。
そして、そのような場合に、補助加熱手段にて給湯用循環経路を通流する湯水を加熱する目標加熱温度として、給湯器における給湯目標温度設定範囲外の温度に設定することにより、給湯用循環経路を通流する湯水の温度が、極力、給湯器における給湯目標温度設定範囲外の温度となるようにして、各住戸の給湯器において、前記設定混合温度になるように一旦水を混合してから、給湯温度が給湯目標温度になるように加熱する形態での運転（以下、水混合後加熱運転と称する場合がある）を極力起こさせないようにして、省エネを図ることが可能となる。
従って、各住戸において給湯用循環手段を通じて供給される湯水を用いて給湯目標温度での給湯を可能にしながら、省エネを図ることができる。
【００１０】
〔請求項４記載の発明〕
請求項４に記載のコージェネレーションシステムは、請求項３において、前記目標加熱温度として、前記設定範囲よりも低い温度に設定されて、冬期に用いられる冬期用目標加熱温度と、前記設定範囲よりも高い温度に設定されて、冬期以外の時期に用いられる夏期中間期用目標加熱温度とが備えられている点を特徴構成とする。
即ち、冬期は、給湯用循環経路を通流する湯水が、補助加熱手段により、給湯器の給湯目標温度設定範囲よりも低い温度に設定される冬期用目標加熱温度に加熱され、夏期及び中間期は、給湯用循環経路を通流する湯水が、補助加熱手段により、給湯器の給湯目標温度設定範囲よりも高い温度に設定される夏期中間期用目標加熱温度に加熱される。
つまり、冬期は、貯湯槽への給水温度が低いために、発電手段の排熱により加熱される貯湯槽の湯水の温度が低いので、補助加熱手段にて、給湯用循環経路を通流する湯水を給湯目標温度設定範囲よりも高い温度に加熱するには、多くの熱量が必要となり、しかも、給湯用循環経路からの放熱量が多くなる。そこで、冬期は、補助加熱手段にて、給湯用循環経路を通流する湯水を給湯目標温度設定範囲よりも低い冬期用目標加熱温度に加熱することにより、各住戸の給湯器では、混合部を混合作動させない状態で加熱部を加熱作動させる形態での運転を可能にして、放熱ロスを少なくしながら、前記水混合後加熱運転を極力起こさせないようにして、省エネを図る。
一方、夏期や中間期は、貯湯槽への給水温度が高くて、発電手段の排熱により加熱される貯湯槽の湯水の温度が高くなり易いことから、補助加熱手段にて加熱することなく、あるいは、比較的少ない熱量で、給湯用循環経路を通流する湯水を給湯目標温度設定範囲よりも高い温度に加熱することが可能となる。そこで、夏期や中間期は、補助加熱手段にて、給湯用循環経路を通流する湯水を給湯目標温度設定範囲よりも高い夏期中間期用目標加熱温度に加熱することにより、各住戸の給湯器は、加熱部を加熱作動させない状態で混合部を混合作動させる形態で運転させるようにして、前記水混合後加熱運転を極力起こさせないようにして、省エネを図る。
従って、各住戸において給湯用循環手段を通じて供給される湯水を用いて給湯目標温度での給湯を可能にしながら、一層省エネを図ることができる。
【００１１】
〔請求項５記載の発明〕
請求項５に記載のコージェネレーションシステムは、請求項２〜４のいずれかにおいて、給水源からの水を前記給湯用循環経路に供給する循環用給水手段が設けられ、
前記給湯用循環手段が、前記貯湯槽の湯水を前記給湯用循環経路にて循環させる貯湯槽湯水循環状態と、前記貯湯槽の湯水の循環を停止させて前記循環用給水手段にて前記給湯用循環経路に給水する給水状態とに切り換え自在に構成され、前記貯湯槽の目標貯留量として、前記非発電時間帯において消費又は略消費可能な貯留量が設定されて、
前記運転制御手段が、前記設定発電時間帯においては、前記貯湯槽に前記目標貯留量の湯水を貯留すべく前記槽用給水手段を作動させる状態で、前記給湯用循環手段を前記貯湯槽湯水循環状態にて作動させ、前記非発電時間帯においては、前記槽用給水手段を停止させる状態で、前記貯湯槽の貯留量が設定下限貯留量よりも多いときは前記給湯用循環手段を前記貯湯槽湯水循環状態にて作動させ、且つ、前記貯湯槽の貯留量が前記設定下限貯留量以下のときは前記給湯用循環手段を前記給水状態にて作動させるように構成されている点を特徴構成とする。
即ち、設定発電時間帯においては、貯湯槽の湯水が発電手段からの排熱にて加熱され、且つ、貯湯槽の貯留量が目標貯留量になるように槽用給水手段にて貯湯槽に給水される状態で、給湯用循環手段が貯湯槽湯水循環状態にて作動されて、貯湯槽の湯水が給湯用循環経路に循環され、非発電時間帯においては、槽用給水手段による貯湯槽への給水が停止される状態で、貯湯槽の貯留量が設定下限貯留量よりも多いときは、給湯用循環手段が貯湯槽湯水循環状態にて作動されて、貯湯槽の湯水が給湯用循環経路に循環され、且つ、貯湯槽の貯留量が設定下限貯留量以下になると、給湯用循環手段が給水状態にて作動されて、給湯用循環経路での貯湯槽の湯水の循環が停止されて、給湯用循環経路には給水源からの水が供給され、並びに、設定発電時間帯と非発電時間帯とを通じて、給湯用循環経路を通流する湯水が補助加熱手段により目標加熱温度に加熱される。
つまり、設定発電時間帯においては、発電手段からの排熱にて目標貯留量で貯留される貯湯槽の湯水を加熱し、その目標貯留量は非発電時間帯において消費又は略消費可能な貯留量に設定することから、発電手段の排熱により加熱する湯水の量を満水状態よりも少なくすることが可能となり、貯湯槽の湯水を高温に加熱し易い。又、非発電時間帯においては、発電手段からの排熱が無くなるものの、貯湯槽への給水が停止されることから、貯湯槽の湯水の温度の低下を抑制することが可能となり、又、目標貯留量は非発電時間帯において消費又は略消費可能な貯留量に設定することから、給水源からの水を補助加熱手段にて加熱する形態での運転を極力無くす、又は、その運転時間を極力短くすることが可能となる。もって、設定発電時間帯と非発電時間帯とを通じて、目標加熱温度に加熱するための補助加熱手段の加熱量を少なくすることが可能となる。
従って、発電手段が１日のうちの一部の設定発電時間帯で運転される場合において、時間帯に係わらず、各住戸に安定した温度にて給湯することを可能としながら、更に、省エネを図ることができる。
【００１２】
【発明の実施の形態】
〔第１実施形態〕
以下、図面に基づいて、本発明の第１実施形態を説明する。
図１に示すように、コージェネレーションシステムは、集合住宅を電力供給対象として発電する発電手段としての発電機１、その発電機１からの排熱が供給される排熱回収用熱交換器２、集合住宅に含まれる複数の住戸Ｈを給湯対象として湯水を貯留する貯湯槽３、その貯湯槽３に給水する槽用給水手段Ｗ１、排熱回収用熱交換器２と貯湯槽３とにわたって湯水を循環させる排熱回収用循環手段Ｃ１、貯湯槽３と集合住宅に含まれる複数の住戸Ｈとにわたる給湯用循環経路Ｒにて湯水を循環させる給湯用循環手段Ｃ２、給水源としての受水槽５からの水を給湯用循環経路Ｒに供給する循環用給水手段Ｗ２、集合住宅に含まれる複数の住戸Ｈのそれぞれに給水する住戸用給水手段Ｗ３、及び、コージェネレーションシステムの運転を制御する運転制御手段としての運転制御部Ｕを設け、並びに、集合住宅に含まれる複数の住戸Ｈのそれぞれに、給湯用循環手段Ｃ２を通じて供給される湯水を用いて住戸Ｈにおける各湯水需要部に供給する給湯器Ｋを設けて構成してある。
【００１３】
又、コージェネレーションシステムには、貯湯槽３の湯水を加熱する貯湯槽用補助加熱手段Ｂ１、給湯用循環経路Ｒを通流する湯水を加熱する循環経路用補助加熱手段Ｂ２、及び、発電機１からの排熱が供給されて、給湯用循環経路Ｒを通流する湯水を加熱する補助加熱用熱交換器６を設けてある。
【００１４】
更に、コージェネレーションシステムには、商用電源６１からの電力を一括して受電する受変電設備６２と、発電機１を商用電源６１と系統連系させる連系装置６３とを設け、発電機１及び商用電源６１からの電力を、共用部における電力消費機器や、集合住宅に含まれる各住戸Ｈの電力消費機器に供給するように給電線６４を配線してある。
【００１５】
説明を加えると、発電機１は、共用部用ガス供給路７を通じて供給される都市ガスを燃料とするガスエンジン（図示省略）を備えて、そのガスエンジンにて駆動する回転式に構成してある。
そして、ガスエンジンと排熱回収用熱交換器２とにわたってエンジン冷却水を循環させる冷却水循環路８を設け、更に、エンジン冷却水の一部を分流して補助加熱用熱交換器６に循環させることが可能なように、冷却水循環路８と補助加熱用熱交換器６とを冷却水分流三方弁Ｖ１を介して分流循環路８ｂにて接続し、冷却水循環路８に冷却水循環ポンプＰ１を設けてある。そして、冷却水循環ポンプＰ１を作動させることにより、エンジン冷却水をガスエンジンと排熱回収用熱交換器２及び補助加熱用熱交換器６の夫々とにわたって循環させるように構成してある。
【００１６】
槽用給水手段Ｗ１は、受水槽５から貯湯槽３に給水する槽用給水路９と、その槽用給水路９に設けた槽用給水ポンプＰ２にて構成してある。
槽用給水ポンプＰ２を作動させると、槽用給水手段Ｗ１が作動することになり、受水槽５の貯留水が槽用給水路９を通じて貯湯槽３に給水され、槽用給水ポンプＰ２を停止させると、槽用給水手段Ｗ１の作動が停止することになる。
受水槽５には、水道水が供給され、詳細な説明及び図示は省略するが、受水槽５の貯留水位が設定水位になるように水道水の供給が断続されるようになっている。
【００１７】
貯湯槽３は、主貯留部３ｍとその主貯留部３ｍよりも横断面積が小さい小貯留部３ｓとを備えて構成し、それら主貯留部３ｍ及び小貯留部３ｓを、互いに連通して、貯湯槽３の貯留量が設定下限貯留量以下のときは全量が小貯留部３ｓで貯留され、貯湯槽３の貯留量が設定下限貯留量より多いときは設定下限貯留量が小貯留部３ｓにて貯留され且つ設定下限貯留量を越える分が主貯留部３ｍにて貯留されるように設けてある。ちなみに、設定下限貯留量は、例えば、貯湯槽３における満水状態での貯留量の１０％程度に設定する。
【００１８】
具体的には、上部が開口した開放型の主貯留部３ｍと、その主貯留部３ｍよりも横断面積が小さい密閉型の小貯留部３ｓを、互いに別体で、且つ、小貯留部３ｓが主貯留部３ｍの底部よりも下方に位置する状態で設け、主貯留部３ｍの底部と小貯留部３ｓの上部とを連通路３ｃにて連通させてある。
又、貯留槽３の主貯留部３ｍには、水位センサＬを設けてある。
【００１９】
排熱回収用循環手段Ｃ１は、貯湯槽３の小貯留部３ｓの底部から取り出した湯水を排熱回収用熱交換器２を経由して主貯留部３ｍの上部から戻すように流すべく配管した排熱回収用循環経路１０と、その排熱回収用循環経路１０における排熱回収用熱交換器２よりも下流側部分から分岐させて湯水を小貯留部３ｓに戻す分岐経路１０ｂと、その分岐部分に設けた槽湯水循環切換三方弁Ｖ２と、排熱回収用循環経路１０に設けた排熱回収用循環ポンプＰ３とを備えて構成してある。つまり、排熱回収用循環ポンプＰ３を作動させると、排熱回収用循環手段Ｃ１が作動することになり、排熱回収用循環ポンプＰ３の作動を停止させると、排熱回収用循環手段Ｃ１が停止することになり、並びに、槽湯水循環切換三方弁Ｖ２の切り換えにより、排熱回収用循環経路１０の復路部分（排熱回収用熱交換器２の出口に接続される流路部分）を通流する湯水を主貯留部３ｍに戻す通常循環状態と、排熱回収用循環経路１０の復路部分を通流する湯水を小貯留部３ｓに戻す槽昇温時循環状態とに切り換え自在に構成してある。
【００２０】
給湯用循環手段Ｃ２は、貯湯槽３と集合住宅に含まれる複数の住戸Ｈとにわたる給湯用循環経路Ｒと、その給湯用循環経路Ｒに設けた上流側循環ポンプＰ４及び下流側循環ポンプＰ５とを備えて構成し、各住戸Ｈには、給湯用循環経路Ｒを流れる湯水を各住戸Ｈに供給する住戸用湯水供給路１１を接続し、各住戸用湯水供給路１１には、各住戸Ｈに供給される湯水の流量を検出する住戸別給湯量センサＱ３を設けてある。
【００２１】
給湯用循環経路Ｒについて説明を加える。貯湯槽３の小貯留部３ｓから取り出した湯水を集合住宅に含まれる複数の住戸Ｈを経由して主貯湯部３ｍの上部に戻すように流すべく配管して、槽経由循環路４を設け、その槽経由循環路４における住戸経由箇所よりも下流側に、槽戻し停止三方弁Ｖ３を設け、その槽戻し停止三方弁Ｖ３と槽経由循環路４における住戸経由箇所よりも上流側とを槽バイパス路１２にて接続し、更に、槽経由循環路４における槽バイパス路１２の接続個所よりも上流側に、逆止弁１３を設けて、槽戻し停止三方弁Ｖ３の切り換えにより、槽経由循環路４を通流する湯水を貯湯槽３に流入させる槽戻し状態と、槽経由循環路４を通流する湯水を貯湯槽３に流入させるのを停止する槽戻し停止状態とに切り換え自在なように構成してある。
上流側循環ポンプＰ４は、槽経由循環路４の住戸経由箇所よりも上流側における槽バイパス路１２の接続個所よりも上流側に設け、下流側循環ポンプＰ５は、槽経由循環路４における住戸経由箇所よりも下流側で且つ槽戻し停止三方弁Ｖ３よりも上流側に設けてある。
【００２２】
そして、槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換えて、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を作動させると、貯湯槽３から取り出された湯水は、槽経由循環路４を複数の住戸Ｈを経由して流れ、更に、槽戻し停止三方弁Ｖ３から槽バイパス路１２を流れて槽経由循環路４に戻る貯湯槽迂回経路にて循環することになり、その貯湯槽迂回経路を流れる湯水が各住戸Ｈにて使用されるのに応じて、上流側循環ポンプＰ４により、貯湯槽３の湯水が前記貯湯槽迂回経路に補充されることになる。
つまり、貯湯槽３と複数の住戸Ｈとにわたる給湯用循環経路Ｒは、槽経由循環路４及び槽バイパス路１２を用いて、貯湯槽３を迂回する状態で複数の住戸Ｈを経由する貯湯槽迂回経路を形成するように構成し、給湯用循環手段Ｃ２は、貯湯槽３の湯水を給湯用循環経路Ｒに補充しながら給湯用循環経路Ｒを通じて循環させるように構成してある。
【００２３】
又、槽経由循環路４における住戸経由箇所よりも下流側で且つ槽戻し停止三方弁Ｖ３よりも上流側に、補助加熱用熱交換器６を設けて、その補助加熱用熱交換器６により、給湯用循環経路Ｒを通流する湯水を加熱するように構成してある。つまり、給湯用循環経路Ｒを通流する湯水を、補助加熱用熱交換器６にて発電機１の排熱にて加熱することにより、放熱による温度低下を抑制するように構成してある。
【００２４】
循環用給水手段Ｗ２は、槽経由循環路４の住戸経由箇所よりも上流側における槽バイパス路１２の接続個所よりも下流側に接続されて受水槽５からの水を給湯用循環経路Ｒに供給する循環給水路１４と、槽経由循環路４における循環給水路１４の接続部分に設けた給水切換三方弁Ｖ４と、循環給水路１４に設けた循環兼住戸用給水ポンプＰ６とを備えて構成してある。
つまり、給水切換三方弁Ｖ４により、貯湯槽３からの湯水の通流を停止して、循環給水路１４から給湯用循環経路Ｒに給水する給水路接続状態と、循環給水路１４からの給水を停止して、貯湯槽３からの湯水を通流させる給水路遮断状態とに切り換え自在なように構成してある。
【００２５】
又、循環給水路１４から住戸用給水路１５を分岐させて、その住戸用給水路１５を複数の住戸Ｈの夫々に給水するように配管してあり、住戸用給水手段Ｗ３は、循環給水路１４と住戸用給水路１５と循環兼住戸用給水ポンプＰ６とを備えて構成してある。
【００２６】
貯湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを兼用する補助給湯器Ｂを設けてある。
その補助給湯器Ｂは、ガス燃焼式の瞬間湯沸し器にて構成し、具体的には、第１及び第２の二つの熱交換器７１，７２と、それら第１及び第２熱交換器７１，７２を加熱するガスバーナ７３と、そのガスバーナ７３に燃焼用空気を通風する送風機７４を備えて構成してある。
第１熱交換器７１の入口には、その第１熱交換器７１に供給される湯水の流量を検出する第１給水量センサＱ１を設け、第１熱交換器７１の出口には、その第１熱交換器７１から出湯される湯水の温度を検出する第１出湯温度センサＴ１を設け、第２熱交換器７２の入口には、その第２熱交換器７２に供給される湯水の流量を検出する第２給水量センサＱ２を設け、第２熱交換器７２の出口には、その第２熱交換器７２から出湯される湯水の温度を検出する第２出湯温度センサＴ２を設けてある。
又、ガスバーナ７３には共用部用ガス供給路７を接続し、その共用部用ガス供給路７には、ガス供給を断続するガス断続弁７５、及び、ガス供給量を調整するガス比例弁７６を設けてある。
【００２７】
補助給湯器Ｂの作動は、運転制御部Ｕにて行われ、その運転制御部Ｕは、第１熱交換器７１及び第２熱交換器７２のうちの少なくとも一方に湯水が流れて、第１給水量センサＱ１及び第２給水量センサＱ２のうちの少なくとも一方の検出湯水流量が設定量以上になることに基づいて、送風機７４を作動させると共にガス断続弁７５を開弁し、図示しない点火プラグを作動させて、ガスバーナ７３を点火させ、後述するようにガス比例弁７６の開度調節により燃焼量を調節し、第１給水量センサＱ１及び第２給水量センサＱ２の両方の検出湯水流量が設定量よりも少なくなると、ガス断続弁７５を閉弁してガスバーナ７３を消火させ、続いて、送風機７４を停止させる。
【００２８】
そして、給湯用循環経路Ｒを通流する湯水を第１熱交換器７１に通流させてから給湯用循環経路Ｒに戻して、各住戸Ｈに供給するように、槽経由循環路４の住戸経由個所よりも上流側部分と第１熱交換器７１とを補助加熱流路１６にて接続し、槽経由循環路４と補助加熱流路１６との接続部には、槽経由循環路４を通流する湯水を第１熱交換器７１に通流させる補助加熱状態と、通流させない補助加熱停止状態とに切り換える補助加熱切換三方弁Ｖ５を設けてある。
槽経由循環路４における補助加熱流路１６との接続個所よりも上流側の個所に、貯湯槽３から取り出される湯水の温度を検出する貯湯槽取り出し温度センサＴ３を設け、槽経由循環路４における住戸経由個所よりも上流側で且つ補助加熱流路１６の接続個所よりも下流側に、各住戸Ｈに供給される湯水の温度を検出する住戸供給温度センサＴ４を設けてある。
【００２９】
又、排熱回収用循環経路１０における往路部分（排熱回収用熱交換器２の入口に接続される流路部分）を通流する湯水を排熱回収用熱交換器２を迂回させて、第２熱交換器７２を通流させてから、排熱回収用循環経路１０における復路部分（排熱回収用熱交換器２の出口に接続される流路部分）に戻すように、排熱回収用循環経路１０と第２熱交換器７２とを槽昇温用流路１７にて接続し、槽昇温用流路１７と排熱回収用循環経路１０との接続部分の夫々には、湯水を熱回収用熱交換器２に通流させる排熱回収状態と、湯水を第２熱交換器７１に通流させる槽昇温状態とに切り換える貯湯槽側槽昇温切換三方弁Ｖ６を設け、槽昇温用流路１７には、槽昇温用ポンプＰ７を設けてある。又、排熱回収用循環経路１０における往路部分の貯湯槽側槽昇温切換三方弁Ｖ６よりも上流側箇所には、貯湯槽３の小貯留部３ｓからの湯水の取り出し温度を検出する小貯留部取り出し温度センサＴ５を設けてある。
【００３０】
更に、槽昇温用流路１７における往路部分（第２熱交換器７２の入口に接続される部分）を通流する湯水を分流して第１熱交換器７１に通流させてから、槽昇温用流路１７における復路部分（第２熱交換器７２の出口に接続される部分）に戻すように、槽昇温用流路１７と補助加熱流路１６とを分流流路１８にて接続し、補助加熱流路１６と分流流路１８との接続部分の夫々には、第１熱交換器７１に給湯用循環経路Ｒからの湯水を通流させる補助加熱状態と、第１熱交換器７１に槽昇温用流路１７からの湯水を通流させる槽昇温状態とに切り換える給湯器側槽昇温切換三方弁Ｖ７を設けてある。
【００３１】
そして、槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換え且つ給水切換三方弁Ｖ４を前記給水路遮断状態に切り換えた状態で、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を作動させると、貯湯槽３の湯水を給湯用循環経路Ｒにて循環させる貯湯槽湯水循環状態となる。
又、槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換え且つ給水切換三方弁Ｖ４を前記給水路接続状態に切り換え、並びに、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させた状態で、循環兼住戸用給水ポンプＰ６を作動させると、給水源としての受水槽５からの水を給湯用循環経路Ｒに供給する給水状態になる。
又、給水切換三方弁Ｖ４を前記給水路接続状態に切り換え、補助加熱切り換え三方弁Ｖ５を前記補助加熱停止状態に切り換え、槽戻し停止三方弁Ｖ３を前記槽戻し状態に切り換え、並びに、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させた状態で、循環兼住戸用給水ポンプＰ６を設定水置換時間の間作動させると、貯湯槽３の湯水の循環を停止させて、給水源としての受水槽５からの水を給湯用循環経路Ｒを通じて貯湯槽３に供給するように流して、給湯用循環経路Ｒ内の湯水をその給湯用循環経路Ｒの略全長にわたって、循環用給水手段Ｗ２にて供給される水にて置換する水置換状態となる。
つまり、給湯用循環手段Ｃ２は、前記貯湯槽湯水循環状態と前記給水状態と前記水置換状態とに切り換え自在なように構成してある。
【００３２】
更に、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態に切り換えた状態で、補助加熱切換三方弁Ｖ５を補助加熱状態に切り換え、給湯器側槽昇温切換三方弁Ｖ７を前記補助加熱状態に切り換えて、バーナ７３を燃焼させると、給湯用循環経路Ｒを通流する湯水を第１熱交換器７１にて加熱することができる。
又、槽湯水循環切換三方弁Ｖ２を前記槽昇温時循環状態に切り換え、貯湯槽側槽昇温切換三方弁Ｖ６及び給湯器側槽昇温切換三方弁Ｖ７を夫々前記槽昇温状態に切り換え、排熱回収用循環ポンプＰ３及び槽昇温用ポンプ７を作動させて、バーナ７３を燃焼させると、小貯留部３ｓの湯水を第１及び第２の両熱交換器７１，７２に通流させる状態で循環させて、加熱することができる。
【００３３】
各住戸Ｈには、都市ガスを供給する住戸用ガス供給路１９を接続してある。
そして、各住戸Ｈにおいては、給湯器Ｋに、住戸用ガス供給路１９、給湯用循環経路Ｒから分岐した住戸用湯水供給路１１及び住戸用給水路１５を接続して、給湯器Ｋにて、給湯用循環手段Ｃ２を通じて供給される湯水及び住戸用給水手段Ｗ３を通じて供給される水を用いて湯水需要部に給湯するように構成してある。
【００３４】
次に、図６に基づいて、各住戸Ｈに設ける給湯器Ｋについて説明する。
給湯器Ｋは、住戸用湯水供給路１１から供給される湯水と住戸用給水路１５から供給される水とを混合する混合部Ｋｍと、その混合部Ｋｍから湯水が加熱対象として供給される加熱部Ｋｈと、給湯目標温度を設定する給湯温度設定部等を備えたリモコン操作部３１を備えて構成してある。
【００３５】
加熱部Ｋｈは、混合部Ｋｍから給水路３２を通じて供給される湯水を加熱して、加熱後の湯水を給湯路３３に供給する給湯用熱交換器３４と、追焚用循環路３５を通流する浴槽（図示省略）の湯水を加熱する追焚用熱交換器３６と、それら給湯用熱交換器３４及び追焚用熱交換器３６を加熱するガスバーナ３７と、加熱部Ｋｈの作動を制御する加熱制御部３８等を備えて構成してある。
【００３６】
ガスバーナ３７には、住戸用ガス供給路１９を接続し、その住戸用ガス供給路１９には、ガス供給を断続するガス断続弁３９、及び、ガス供給量を調整するガス比例弁４０を設けてある。
【００３７】
給水路３２には、供給される湯水の温度を検出する給水温度センサ４１、供給される湯水の流量を検出する給水量センサ４２を設け、給水路３２と給湯路３３とを給水バイパス路４３にて接続してある。
給湯路３３には、上流側から順に、給湯用熱交換器３４からの湯水と給水バイパス路４３からの水との混合比を調整するミキシング弁４５、湯水の量を調整する水比例弁５０と、ミキシング弁４５にて混合された湯水の温度を検出する給湯温度センサ４４を設け、給湯路３３の先端には、給湯栓４９を接続してある。
給湯路３３から分岐した湯張り路４６を追焚用循環路３５における往路部分に接続し、湯張り路４６には湯張り用開閉弁４７を設けてある。
又、追焚用循環路３５における復路部分には、浴槽水を循環させる浴槽用循環ポンプ４８を設けてある。
【００３８】
混合部Ｋｍは、住戸用湯水供給路１１（即ち、給湯用循環手段Ｃ２）から供給される湯水と住戸用給水路１５（即ち、住戸用給水手段Ｗ３）から供給される水との混合比を調整するミキシング弁５１と、住戸用湯水供給路１１からミキシング弁５１への湯水供給を断続する湯水供給路開閉弁５２と、住戸用湯水供給路１１からミキシング弁５１へ供給される湯水の温度（以下、循環湯水温度と称する場合がある）を検出する循環湯水温度センサ５３と、住戸用給水路１５からミキシング弁５１へ供給される水の温度（混合部給水温度と称する場合がある）を検出する給水温度センサ５４と、ミキシング弁５１から流出した湯水の温度（以下、混合湯水温度と称する場合がある）を検出する混合温度センサ５５と、混合部Ｋｍの作動を制御する混合制御部５６等を備えて構成してある。
【００３９】
次に、加熱制御部３８及び混合制御部５６の制御動作について説明する。
加熱制御部３８は、リモコン操作部３１及び混合制御部５６夫々との間で各種の制御情報を通信するように構成するように構成してある。
リモコン操作部３１の運転スイッチがオンされると、加熱制御部３８及び混合制御部５６夫々の制御が可能となり、湯水供給路開閉弁５２が開かれた運転可能状態となる。
そして、給湯栓４９が開かれて、給水量センサ４２の検出湯水流量が設定量以上になると、加熱制御部３８は、混合制御部５６に対して、リモコン操作部３１にて設定された給湯目標温度を送信し、混合制御部５６は、循環湯水温度センサ５３にて検出された循環湯水温度と加熱制御部３８から送られてきた給湯目標温度とを比較して、循環湯水温度が給湯目標温度に対して設定温度差Δｔ低い温度よりも高い温度（以下、非燃焼制御用温度と称する場合がある）のときは、その旨を、循環湯水温度が給湯目標温度より設定温度差Δｔ以上低い温度（以下、燃焼制御用温度と称する場合がある）のときはその旨をそれぞれ加熱制御部３８に送信する。
又、混合制御部５６には、予め、設定混合温度を設定して記憶させてある。
【００４０】
設定温度差Δｔは、加熱対象の湯水を給湯目標温度に加熱するのに必要なガスバーナ３７の燃焼量が、そのガスバーナ３７の最小燃焼量（詳細は後述）よりも多くなる状態に対応する温度差に設定してあり、その設定温度差Δｔとしては、リモコン操作部３１で設定される給湯目標温度が予め設定してある通常給湯目標温度範囲（例えば３７〜４４°Ｃ）のときに対応する通常給湯目標温度用の設定温度差Δｔ（例えば２°Ｃ）と、リモコン操作部３１で設定される給湯目標温度が予め設定してある高温給湯目標温度（例えば６０°Ｃ）のときに対応する高温給湯目標温度用の設定温度差Δｔ（例えば３°Ｃ）との２種類を設定してある。
又、設定混合温度は、給湯目標温度よりも設定温度差Δｔ以上低くなるように設定し、その設定混合温度としては、リモコン操作部３１で設定される給湯目標温度が前記通常給湯目標温度範囲のときに対応するものであり、その通常給湯目標温度範囲よりも設定温度差Δｔ以上低い温度に設定した低設定混合温度（例えば３０°Ｃ）と、リモコン操作部３１で設定される給湯目標温度が前記高温給湯目標温度のときに対応する高設定混合温度（例えば４５°Ｃ）との２種類を設定してある。
【００４１】
給湯栓４９が開かれて給水量センサ４２の検出湯水流量が設定量以上になることに基づいて、加熱制御部３８から給湯目標温度が送信されてくると、混合制御部５６は、循環湯水温度センサ５３にて検出される循環湯水温度と給湯目標温度とを比較して、循環湯水温度が前記非燃焼制御用温度のときは、循環湯水温度センサ５３、給水温度センサ５４及び混合温度センサ５５夫々の検出温度に基づいて、混合温度センサ５５にて検出される混合湯水温度が給湯目標温度になるようにミキシング弁５１を調整するミキシング制御を実行して、住戸用湯水供給路１１からの湯水と住戸用給水路１５からの水を混合し、且つ、循環湯水温度が前記非燃焼制御用温度である旨を加熱制御部３８に送信する。
加熱制御部３８は、混合制御部５６から循環湯水温度が前記非燃焼制御用温度である旨が送信されてくると、ガスバーナ３７を燃焼停止状態とする。
従って、混合部Ｋｍから加熱部Ｋｈに供給された湯水は加熱部Ｋｈにて加熱されずに給湯栓４９から出湯することになり、給湯栓４９からは給湯目標温度又は略給湯目標温度の湯水が出湯する。
【００４２】
例えば、給湯目標温度が４０°Ｃに設定されているときは、循環湯水温度が、給湯目標温度の４０°Ｃよりも設定温度差Δｔ、即ち２°Ｃ低い３８°Ｃよりも高いときが、前記非燃焼制御用温度となる。そして、循環湯水温度が３８°Ｃよりも高く、４０°Ｃ以下の範囲では、住戸用湯水供給路１１からの湯水が、住戸用給水路１５からの水が混合されること無くそのまま出湯され、循環湯水温度が４０°Ｃよりも高いときは、混合湯水温度が給湯目標温度になるように、住戸用湯水供給路１１からの湯水に住戸用給水路１５からの水が混合されて出湯される。
【００４３】
一方、循環湯水温度が燃焼制御用温度のときは、循環湯水温度センサ５３、給水温度センサ５４及び混合温度センサ５５夫々の検出温度に基づいて、混合温度センサ５５にて検出される混合湯水温度が、給湯目標温度が通常給湯目標温度範囲のときは低設定混合温度になるように、あるいは、給湯目標温度が高温給湯目標温度のときは高設定混合温度になるように、ミキシング弁５１を調整するミキシング制御を実行して、住戸用湯水供給路１１からの湯水と住戸用給水路１５からの水を混合し、且つ、循環湯水温度が燃焼制御用温度である旨を加熱制御部３８に送信する。
加熱制御部３８は、混合制御部５６から循環湯水温度が燃焼制御用温度である旨が送信されてくると、ガスバーナ３７を燃焼させ、給湯目標温度、給水温度センサ４１の検出温度及び給水量センサ４２の検出給水量に基づいて、給湯用熱交換器３４から流出する湯水の温度が給湯目標温度になるように、ガス比例弁４０の開度及びミキシング弁４５の開度を調節するフィードフォワード制御を実行し、且つ、給湯温度センサ４４の検出温度と給湯目標温度との偏差に基づいてガス比例弁４０の開度を微調整するフィードバック制御を実行する。
従って、給湯栓４９からは給湯目標温度の湯水が出湯することになる。
【００４４】
例えば、給湯目標温度が４０°Ｃに設定されているときは、循環湯水温度が、給湯目標温度の４０°Ｃよりも設定温度差Δｔ、即ち２°Ｃ低い３８°Ｃ以下のときが、前記燃焼制御用温度となる。そして、混合部Ｋｍにおいて、混合湯水温度が低設定混合温度（例えば３０°Ｃ）になるように、住戸用湯水供給路１１からの湯水に住戸用給水路１５からの水が混合され、加熱部Ｋｈで給湯目標温度の４０°Ｃに加熱されて出湯されることになる。
【００４５】
つまり、給湯器Ｋは、前記循環湯水温度が給湯目標温度よりも設定温度差Δｔ以上低いときは、給湯目標温度よりも設定温度差Δｔ以上低くなるように設定された前記設定混合温度になるように混合部Ｋｍの混合作動を制御し、且つ、給湯温度が前記給湯目標温度になるように加熱部Ｋｈの加熱作動を制御し、前記循環湯水温度が給湯目標温度に対して設定温度差Δｔ低い温度よりも高いときは、加熱部Ｋｈの加熱作動を停止させた状態で、給湯温度が給湯目標温度になるように混合部Ｋｍの混合作動を制御するように構成してある。
【００４６】
給湯用循環手段Ｃ２からの湯水の温度が燃焼制御用温度のときは、給湯目標温度への温度調節が安定して行えるような設定混合温度になるように、給湯用循環手段Ｃ２からの湯水と住戸用給水手段Ｗ３からの水とが混合されてから、加熱部Ｋｈにて給湯目標温度になるように加熱されるので、給湯用循環手段Ｃ２からの湯水の温度と給湯目標温度との差が小さいときでも、給湯目標温度又は略給湯目標温度の湯水が得られる。
つまり、ガスバーナ３７の燃焼安定性を確保するために、ガスバーナ３７の燃焼量は所定の最小燃焼量よりも小さくは絞れないようにしてある。従って、前述の如き湯水混合制御、即ち、給湯用循環手段Ｃ２からの湯水と住戸用給水手段Ｗ３からの水とを設定混合温度になるように混合する制御を行わないときは、給湯用循環手段Ｃ２からの湯水の温度と給湯目標温度との差が小さくて、その差に基づいて求めた燃焼量が最小燃焼量よりも小さいときは、例えば、ガスバーナ３７を最小燃焼量にて燃焼させるようになるので、出湯する湯水の温度を給湯目標温度に調整し難いといった不具合が生じることになる。そこで、前述の如き湯水混合制御を行うことにより、前述の如き不具合が解消されることになる。
【００４７】
次に、運転制御部Ｕについて説明を加える。
運転制御部Ｕは、１日のうちの一部の時間帯として設定される設定発電時間帯においては発電機１、排熱回収用循環手段Ｃ１及び給湯用循環手段Ｃ２を作動させ、その設定発電時間帯以外の非発電時間帯においては発電機１及び排熱回収用循環手段Ｃ１を停止させ且つ給湯用循環手段Ｃ２を作動させる形態で、且つ、設定発電時間帯及び非発電時間帯においては、給湯用循環経路Ｒを通流する湯水を目標加熱温度に加熱するように補助給湯器Ｂを加熱作動させる形態で運転を制御するように構成してある。
又、貯湯槽１の目標貯留量として、前記非発電時間帯において消費又は略消費可能な貯留量に設定して、運転制御部Ｕは、設定発電時間帯においては、貯湯槽１に前記目標貯留量の湯水を貯留すべく槽用給水手段Ｗ１を作動させる状態で、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させ、非発電時間帯においては、槽用給水手段Ｗ１を停止させる状態で、貯湯槽３の貯留量が設定下限貯留量よりも多いときは給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させ、且つ、貯湯槽３の貯留量が前記設定下限貯留量以下のときは給湯用循環手段Ｃ２を前記給水状態にて作動させるように構成してある。
【００４８】
運転制御部Ｕに内蔵した記憶部には、前記設定発電時間帯、前記設定下限量に対応する貯湯槽３の水位である設定下限水位、前記水質維持温度、前記貯湯槽水質維持運転を継続して実行する設定水質維持運転時間、前記設定水置換時間、並びに、補助給湯器Ｂにて給湯用循環経路Ｒを通流する湯水を加熱するための目標加熱温度の夫々を予め設定して記憶させてある。
ちなみに、前記設定発電時間帯としては、夏期中間期用と冬期用との２種類を設定して記憶させてあり、夏期中間期用の設定発電時間帯は、電力需要の多い時間帯である１８時から２４時までの時間帯に設定し、冬期用の設定発電時間帯は、熱需要が夏期に比べて多いので、熱需要に対応するように、冬期用の設定発電時間帯よりも長い１４時から２３時までの時間帯に設定してある。尚、設定発電時間帯と非発電時間帯とを加えた時間帯（２４時間）を１サイクルと称する。
【００４９】
前記設定下限貯留量は、小貯留部３ｓにおける満水状態での貯留量に設定してあるので、前記設定下限水位は主貯留部３ｍの水位がゼロとなる水位に設定してある。即ち、貯湯槽３の水位が前記設定下限水位の時は、湯水の全量が小貯留部３ｓに貯留され、主貯留部３ｍには貯留されない状態にすることが可能となる。
【００５０】
前記水質維持温度は、例えば６０°Ｃに設定し、前記設定水質維持運転時間は例えば１時間に設定してある。
前記設定水置換時間は、給水切換三方弁Ｖ４を前記給水路接続状態に切り換えた時に給湯用循環経路Ｒに流入した受水槽５の水が、給湯用循環経路Ｒを流れて、貯湯槽３に対して流出するまでに要する時間以上に設定してある。
【００５１】
前記目標加熱温度は、各住戸Ｈに設けられた給湯器Ｋのリモコン操作部３１にて設定可能な通常給湯目標温度の設定範囲（例えば３７〜４４°Ｃ）外の温度に設定してある。
そして、前記目標加熱温度は、前記通常給湯目標温度設定範囲よりも低く且つ前記低設定混合温度と同温度（例えば３０°Ｃ）に設定されて、冬期（例えば、１２〜２月）に用いられる冬期用目標加熱温度と、前記通常給湯目標温度設定範囲よりも高い温度（例えば４５°Ｃ）に設定されて、冬期以外の時期に用いられる夏期中間期用目標加熱温度とを記憶させてある。
【００５２】
又、給湯用循環手段Ｃ２にて集合住宅に含まれる複数の住戸Ｈに供給した湯水の熱量を熱負荷として検出する熱負荷検出手段を設けると共に、その熱負荷検出手段にて検出される前記非発電時間帯における熱負荷（以下、単に非発電時間帯熱負荷と称する場合がある）を前記記憶部に記憶するように構成してあり、運転制御手段Ｕは、前記記憶部に記憶されている非発電時間帯熱負荷の記憶情報に基づいて、運転対象サイクルの前記目標貯留量を設定するように構成してある。
【００５３】
具体的には、運転制御手段Ｕは、各住戸別給湯量センサＱ３及び住戸供給温度センサＴ４夫々の検出情報に基づいて、前記非発電時間帯を通じて、各住戸別給湯量センサＱ３の検出流量を合計した合計湯水流量に住戸供給温度センサＴ４の検出温度を乗じて熱量を演算すると共に、その熱量を積算し、その積算した総熱量を、前記非発電時間帯熱負荷として求め、前記記憶手段に記憶されている前記非発電時間帯熱負荷の記憶情報を新たに求めた前記非発電時間帯熱負荷熱に書き換えるように構成してある。つまり、前記熱負荷検出手段は、住戸別給湯量センサＱ３と住戸供給温度センサＴ４とから構成してある。
そして、運転制御手段Ｕは、前記記憶手段に記憶されている前記非発電時間帯熱負荷、即ち、運転対象サイクルの前のサイクルにおける前記非発電時間帯熱負荷に基づいて、運転対象サイクルの前記目標貯留量を設定するように構成してある。
【００５４】
以下、運転制御部Ｕの制御動作を、共用部及び各住戸Ｈに給電する給電制御と、各住戸に給湯する給湯制御とに分けて説明を加える。
先ず、給電制御の制御動作について説明を加える。
運転制御部Ｕは、前記設定発電時間帯においては、発電機１及び冷却水循環ポンプＰ１を運転し、その設定発電時間帯以外の非発電時間帯においては、発電機１及び冷却水循環ポンプＰ１を停止させる形態で、発電機１を毎日自動運転する。
そして、発電機１の運転中は、共用部の電力消費機器や各住戸Ｈの電力消費機器に対して発電機１にて給電されると共に、それらの電力消費機器に対して発電機１の出力が不足する場合には、その不足分が商用電源６１にて補われる。
又、発電機１の停止中は、共用部の電力消費機器や各住戸Ｈの電力消費機器に対して、商用電源６１にて給電される。
又、発電機１の運転中は、エンジン冷却水が排熱回収用熱交換器２及び補助加熱用熱交換器６を通って循環して、ガスエンジンが冷却される共に、その排熱が、排熱回収用熱交換器２及び補助加熱用熱交換器６に供給されることになる。
【００５５】
次に、給湯制御について、図１ないし図５に基づいて説明する。尚、図１ないし図５において、湯水やエンジン冷却水が流れる状態となっている各流路部分を太線にて示す。
尚、住戸用給水路１５を通じて、常時、各住戸Ｈに受水槽５の水が給水可能なように、循環兼住戸用給水ポンプＰ６は常時作動させているので、以下の説明では、循環兼住戸用給水ポンプＰ６の作動制御の説明は省略する。
【００５６】
前記設定発電時間帯の開始に伴い、排熱回収用循環手段Ｃ１を作動させ、且つ、目標貯留量を貯留すべく槽用給水手段Ｗ１を作動させ、且つ、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させる通常貯湯槽湯水循環運転を実行する。
つまり、槽湯水循環切換三方弁Ｖ２を前記通常循環状態に切り換え且つ貯湯槽側槽昇温切換三方弁Ｖ６を前記排熱回収状態に切り換えた状態で、排熱回収用循環ポンプＰ３を作動させることにより、排熱回収用循環手段Ｃ１を作動させ、並びに、給水切換三方弁Ｖ４を前記給水路遮断状態に切り換え且つ槽戻し停止三方弁Ｖ３を前記槽戻し停止状態に切り換えた状態で、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を作動させることにより、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させ、並びに、水位センサＬの検出情報に基づいて、貯湯槽３の貯留量が目標貯留量になるように、槽用給水ポンプＰ２を作動させることにより、貯湯槽３に目標貯留量を貯留すべく槽用給水手段Ｗ１を作動させる。
【００５７】
図１に示すように、通常貯湯槽湯水循環運転においては、エンジン冷却水は排熱回収用熱交換器２及び補助加熱用熱交換器６を通って循環し、貯湯槽３の湯水は、排熱回収用循環経路１０にて排熱回収用熱交換器２を通って循環し、並びに、給湯用循環経路Ｒにて複数の住戸Ｈを巡って循環し、貯湯槽３の貯留量が目標貯留量に維持されるように、槽用給水路９を通じて貯湯槽３に給水される。
つまり、貯湯槽３の小貯留部３ｓから取り出された湯水が排熱回収用熱交換器２におけるエンジン冷却水との熱交換作用にて加熱されて主貯留部３ｍに戻されることにより、貯湯槽３の湯水が加熱され、その貯湯槽３の湯水が、複数の住戸Ｈを経由し、且つ、補助加熱用熱交換器６にてエンジン冷却水との熱交換作用にて加熱される状態で給湯用循環経路Ｒを通じて循環する。
【００５８】
又、通常貯湯槽湯水循環運転中は、以下のように、補助加熱制御を実行する。即ち、貯湯槽取り出し温度センサＴ３の検出温度が目標加熱温度以上のときは、補助加熱切換三方弁Ｖ５を前記補助加熱停止状態に切り換える。又、貯湯槽取り出し温度センサＴ３の検出温度が目標加熱温度よりも低いときは、補助加熱切換三方弁Ｖ５を前記補助加熱状態に切り換え且つ給湯器側槽昇温切換三方弁Ｖ７を前記補助加熱状態に切り換える。すると、補助給湯器Ｂの第１熱交換器に湯水が通流して、第１給水量センサＱ１の検出流量が設定量以上になるので、それに基づいて、上述のようにガスバーナ７３を点火させると共に、第１熱交換器７１からの出湯温度が加熱目標温度になるように、燃焼量制御を実行する。即ち、燃焼量制御では、加熱目標温度、貯湯槽取り出し温度センサＴ３の検出温度及び第１給水量センサＱ１の検出給水量に基づいて、第１熱交換器７１から流出する湯水の温度が加熱目標温度になるように、ガス比例弁７６の開度を調節するフィードフォワード制御を実行し、並びに、第１出湯温度センサＴ１の検出温度と加熱目標温度との偏差に基づいてガス比例弁７６の開度を微調整するフィードバック制御を実行する。
【００５９】
各住戸Ｈにおいては、以下のように、給湯用循環経路Ｒを流れる湯水を用いて給湯器Ｋにより給湯することになる。
即ち、夏期及び中間期は、加熱目標温度が通常給湯目標温度設定範囲よりも高い夏期中間期用目標加熱温度に設定されるので、補助給湯器Ｂにより補助加熱する、しないに係わらず、給湯用循環経路Ｒの住戸経由箇所を通常給湯目標温度設定範囲よりも高い温度の湯水が流れることになるので、各住戸Ｈにおいては、給湯目標温度が通常給湯目標温度設定範囲に設定されているときは、給湯器Ｋを、加熱部Ｋｈを加熱作動させない状態で混合部Ｋｍを混合作動させる形態で運転させるようにして、前記水混合後加熱運転を起こさせないようにして、省エネを図ることができる。
冬期は、加熱目標温度が通常給湯目標温度設定範囲よりも低くて前記低設定混合温度と同じである冬期目標加熱温度に設定される。冬期は、通常は、発電機１の排熱による加熱だけでは、貯湯槽３の湯水を冬期目標加熱温度以上に加熱することができない場合が多いので、給湯用循環経路Ｒの住戸経由箇所を前記低設定混合温度の湯水が流れることが多くなるので、各住戸Ｈにおいては、給湯目標温度が通常給湯目標温度設定範囲に設定されているときは、給湯器Ｋを、混合部Ｋｍを混合作動させない状態で加熱部Ｋｈを加熱作動させる形態で主として運転させることが可能となり、前記水混合後加熱運転が極力起こらないようにして、省エネを図ることができる。
【００６０】
前記設定発電時間帯が終了して、非発電時間帯が始まると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１を停止させ、且つ、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて作動させる水補給停止貯湯槽湯水循環運転を実行する。
【００６１】
つまり、上述の通常貯湯槽湯水循環運転の制御状態から、排熱回収用循環ポンプＰ３を停止させることにより、排熱回収用循環手段Ｃ１を停止させ、並びに、槽用給水ポンプＰ２を停止させることにより、槽用給水手段Ｗ１を停止させるが、給湯用循環手段Ｃ２は継続して前記貯湯槽湯水循環状態にて作動させる。
【００６２】
図２に示すように、水補給停止貯湯槽湯水循環運転においては、エンジン冷却水の循環が停止し、排熱回収用循環経路１０を通じての貯湯槽３の湯水の循環が停止して、発電機１の排熱による貯湯槽３の湯水の加熱が停止され、且つ、受水槽５からの貯湯槽３への水の補給が停止された状態で、貯湯槽３の湯水が給湯用循環経路Ｒにて複数の住戸Ｈを巡って循環する。
【００６３】
水補給停止貯湯槽湯水循環運転中も、上述の補助加熱制御を実行する。
水補給停止貯湯槽湯水循環運転中に、給湯用循環経路Ｒの住戸経由箇所を流れる湯水の温度の状態は、上述の通常貯湯槽湯水循環運転中と同様であるので、各住戸Ｈにおいては、上述の通常貯湯槽湯水循環運転中と同様に、給湯用循環経路Ｒを流れる湯水を用いて給湯器Ｋにより給湯することになるので、説明を省略する。
【００６４】
非発電時間帯中に、次の設定発電時間帯の開始時間に対して、前記設定水質維持運転時間と前記設定水置換時間とを加えた水質維持所要時間以上前の時間に、水位センサＬの検出水位が前記設定下限水位になり、主貯留部３ｍの貯留量がゼロとなって、全量が小貯留部３ｓに貯留される状態、即ち、貯湯槽３の貯留量が設定下限貯留量になると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１の停止状態を維持した状態で、給湯用循環手段Ｃ２を前記給水状態にて作動させて、給水状態運転を実行する。
【００６５】
つまり、上述の水補給停止貯湯槽湯水循環運転の制御状態から、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させ、且つ、給水切換三方弁Ｖ４を前記給水路接続状態に切り換えることにより、給湯用循環手段Ｃ２を給水状態にて作動させる。
【００６６】
図３に示すように、給水状態運転においては、排熱回収用循環経路１０及び給湯用循環経路Ｒを通じての貯湯槽３の湯水の循環が停止し、且つ、受水槽５からの貯湯槽３への水の補給が停止された状態で、受水槽５の水が給水切換三方弁Ｖ４を通じて給湯用循環経路Ｒに供給される。
【００６７】
給水状態運転中も、上述の補助加熱制御を実行する。
給水状態運転中に、給湯用循環経路Ｒの住戸経由箇所を流れる湯水の温度の状態は、上述の通常貯湯槽湯水循環運転中と同様であるので、各住戸Ｈにおいては、上述の通常貯湯槽湯水循環運転中と同様に、給湯用循環経路Ｒを流れる湯水を用いて給湯器Ｋにより給湯することになるので、説明を省略する。
【００６８】
非発電時間帯中に、給水状態運転を実行しているとき及び実行していないときにかかわらず、次の設定発電時間帯の開始時間よりも水質維持所要時間前の時間、即ち、非発電時間帯の設定終期になると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１の停止状態を維持し、且つ、給湯用循環手段Ｃ２を前記給水状態に作動させる状態を維持した状態で、貯湯槽３の湯水を、湯水の水質を維持することが可能な水質維持温度にまで加熱するように、補助加熱用給湯器Ｂを加熱作動させる貯湯槽水質維持運転を前記設定水質維持運転時間の間実行する。
【００６９】
つまり、給水状態運転を実行しているときは、給水状態運転の制御状態から、補助加熱切換三方弁Ｖ５を前記補助加熱停止状態に切り換え、槽湯水循環切換三方弁Ｖ２を前記槽昇温状態に切り換え、貯湯槽側槽昇温切換三方弁Ｖ６及び給湯器側槽昇温切換三方弁Ｖ７を夫々前記槽昇温状態に切り換え、並びに、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を作動させ、給水状態運転を実行していないときは、上述の水補給停止貯湯槽湯水循環運転の制御状態から、上流側循環ポンプＰ４及び下流側循環ポンプＰ５を停止させ、且つ、給水切換三方弁Ｖ４を前記給水路接続状態に切り換え、更に、補助加熱切換三方弁Ｖ５を前記補助加熱停止状態に切り換え、槽湯水循環切換三方弁Ｖ２を前記槽昇温状態に切り換え、貯湯槽側槽昇温切換三方弁Ｖ６及び給湯器側槽昇温切換三方弁Ｖ７を夫々前記槽昇温状態に切り換え、並びに、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を作動させる。
【００７０】
図４に示すように、貯湯槽水質維持運転においては、受水槽５からの貯湯槽３への水の補給が停止され、又、給湯用循環経路Ｒ内の湯水の貯湯槽３に対する流出が阻止された状態で、受水槽５の水が給水切換三方弁Ｖ４を通じて給湯用循環経路Ｒに供給されて、補助給湯器Ｂを通過することなく給湯用循環経路Ｒを流れ、並びに、貯湯槽３の小貯留部３ｓの湯水が、補助給湯器Ｂの第１熱交換器７１及び第２熱交換器７２の両方に通流されて加熱された後、分岐流路１０ｂを通じて小貯留部３ｓに戻されるように循環される。各住戸Ｈにおいては、給湯用循環経路Ｒを流れる受水槽５の水を用いて、給湯器Ｋにて給湯することになる。
又、貯湯槽水質維持運転の実行中は、水質維持温度、小貯留部取り出し温度センサＴ５の検出温度及び第１給水量センサＱ１の検出給水量に基づいて、第１熱交換器７１から流出する湯水の温度が水質維持温度になるように、ガス比例弁７６の開度を調節するフィードフォワード制御を実行し、並びに、第１出湯温度センサＴ１の検出温度と水質維持温度との偏差に基づいてガス比例弁７６の開度を微調整するフィードバック制御を実行する。
貯湯槽水質維持運転により、小貯留部３ｓの湯水が水質維持温度に加熱され、しかも、小貯留部３ｓの湯水を第１熱交換器７１及び第２熱交換器７２の両方で加熱することから、貯湯槽水質維持運転の運転時間を短縮することが可能となる。
【００７１】
貯湯槽水質維持運転が終了すると、給湯用循環手段Ｃ２を前記水置換状態にて運転する水置換運転を実行する。
つまり、貯湯槽水質維持運転の制御状態から、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を停止させて、補助給湯器Ｂによる小貯留３ｓの湯水の加熱を停止し、槽戻し停止三方弁Ｖ３を前記槽戻し状態に切り換え、その状態を、前記設定水置換時間の間継続する。
【００７２】
図５に示すように、水置換運転では、受水槽５の水が給水切換三方弁Ｖ４を通じて給湯用循環経路Ｒに供給されて、補助給湯器Ｂを通過することなく給湯用循環経路Ｒを流れて、主貯留部３ｍに流出して、給湯用循環経路Ｒ内の湯水が、給湯用循環経路Ｒの略全長にわたって、受水槽５の水道水にて置換されて、給湯用循環経路Ｒの湯水の水質が維持されることになる。しかも、給湯用循環経路Ｒの湯水を受水槽５の水道水にて置換するので、水道水に含まれる塩素の殺菌作用により、給湯用循環経路Ｒの湯水の水質が一層向上する。
そして、水置換運転が終了して、次の設定発電時間帯が開始するのに伴って、通常貯湯槽湯水循環運転を実行する。
【００７３】
又、運転制御部Ｕは、非発電時間帯の間は、各住戸別給湯量センサＱ３及び住戸供給温度センサＴ４夫々の検出情報に基づいて、前述のようにして、前記非発電時間帯熱負荷を求め、前記記憶手段に記憶されている前記非発電時間帯熱負荷の記憶情報を新たに求めた前記非発電時間帯熱負荷熱に書き換える。運転制御部Ｕは、このように書き換えた前記非発電時間帯熱負荷と前記加熱目標温度とに基づいて、運転対象サイクルの目標貯留量を求める。
【００７４】
又、図示を省略するが、運転制御部Ｕに各種の運転指令を指令する操作盤には、メンテナンス用運転の実行を人為的に指令するメンテナンス用運転指令部を設けてある。
運転制御部Ｕは、メンテナンス用運転が指令されると、排熱回収用循環手段Ｃ１及び槽用給水手段Ｗ１を停止し、且つ、給湯用循環手段Ｃ２を前記給水状態にて作動させるメンテナンス用運転を実行する。
このメンテナンス用運転の制御動作は、上述の給水状態運転と同様であり、受水槽５からの水の流動状態も、上述の給水状態運転と同様であるので、それらの説明を省略する。
このメンテナンス用運転は、発電機３から排熱を供給できない発電機３の故障時又はメンテナンス時や、貯湯槽３に湯水を貯留できない貯湯槽３のメンテナンス時に行うものであり、発電機３の故障時又はメンテナンス時や、あるいは、貯湯槽３のメンテナンス時にも、各住戸Ｈに給湯用循環経路Ｒを通じて給湯することが可能となる。
【００７５】
次に、上述のように構成したコージェネレーションシステムの時間経過に伴う運転パターンを説明する。
図７は冬期における運転パターンの一例を示し、図８は夏期における運転パターンの一例を示す。冬期においては１４時から２３時まで、夏期において１８時から２４時までの設定発電時間帯は、発電機１を運転すると共に、通常貯湯槽湯水循環運転を実行する。尚、図７及び図８においては、発電機１の運転状態を、発電機１から排熱が発生していることにより示している。この通常貯湯槽湯水循環運転の実行中は、貯湯槽３の貯留量が目標貯留量に維持され、貯湯槽３の湯水の温度は成り行きとなり、給湯用循環経路Ｒを流れる湯水の温度が目標加熱温度よりも低くなると、補助給湯器Ｂにて目標加熱温度になるように加熱される。
設定発電時間帯が終了するのに伴って、発電機１を停止すると共に、水補給停止貯湯槽湯水循環運転を実行し、この水補給停止貯湯槽湯水循環運転の実行中に、図７に示すように、次の設定発電時間帯の開始時間に対して水質維持所要時間以上前の時間に、貯湯槽３の貯留量が設定下限貯留量以下になると、給水状態運転を実行する。この水補給停止貯湯槽湯水循環運転及び給水状態運転の実行中は、給湯用循環経路Ｒを流れる湯水の温度が目標加熱温度よりも低くなると、補助給湯器Ｂにて目標加熱温度になるように加熱される。図８では、次の設定発電時間帯の開始時間よりも水質維持所要時間前になるまで、貯湯槽３の貯留量が設定下限貯留量よりも多い状態に維持されて、給水状態運転が実行されない運転パターンを示す、
続いて、次の設定発電時間帯の開始時間よりも水質維持所要時間前の時間になると、貯湯槽水質維持運転を実行する。その貯湯槽水質維持運転により、貯湯槽３の湯水が水質維持温度にまで加熱される。
続いて、貯湯槽水質維持運転が終了すると、水置換運転を実行する。この水置換運転により、給湯用循環経路Ｒの湯水が、その略全長にわたって、受水槽５の水と置換される。
【００７６】
以下、本発明の第２及び第３の各実施形態を説明するが、第１実施形態と同じ構成要素や同じ作用を有する構成要素については、重複説明を避けるために、同じ符号を付すことにより説明を省略し、主として、第１実施形態と異なる構成を説明する。
【００７７】
〔第２実施形態〕
以下、第２実施形態を説明する。
図９に示すように、第２実施形態においては、コージェネレーションシステムの構成は、上記の第１実施形態と同様であり、運転制御部Ｕの制御動作は、第１実施形態における水置換運転に代えて、給湯用循環経路Ｒ内の湯水を、湯水の水質を維持することが可能な水質維持温度にまで加熱するように、補助給湯器Ｂを加熱作動させる循環経路水質維持運転を実行する点で異なる以外は、第１実施形態と同様である。
【００７８】
即ち、循環経路水質維持運転では、貯湯槽水質維持運転に引き続いて、給湯用循環経路Ｒを通流する湯水を補助給湯器Ｂにて水質維持温度に加熱する状態で、給湯用循環手段Ｃ２を前記貯湯槽湯水循環状態にて運転する。
つまり、貯湯槽水質維持運転の制御状態から、排熱回収用循環ポンプＰ３及び槽昇温用ポンプＰ７を停止させて、補助給湯器Ｂによる小貯留３ｓの湯水の加熱を停止し、給水切換三方弁Ｖ４を前記給水路遮断状態に切り換え、補助加熱切換三方弁Ｖ５及び給湯器側槽昇温切換三方弁Ｖ７をそれぞれ前記補助加熱状態に切り換え、槽戻し停止三方弁Ｖ３を前記槽戻し状態に切り換え、その状態を、前記設定水置換時間の間継続する。
又、水質維持温度、貯湯槽取り出し温度センサＴ３の検出温度及び第１給水量センサＱ１の検出給水量に基づいて、第１熱交換器７１から流出する湯水の温度が水質維持温度になるように、ガス比例弁７６の開度を調節するフィードフォワード制御を実行し、並びに、第１出湯温度センサＴ１の検出温度と水質維持温度との偏差に基づいてガス比例弁７６の開度を微調整するフィードバック制御を実行する。
【００７９】
図９に示すように、循環経路水質維持運転においては、受水槽５からの貯湯槽３への水の補給が停止された状態で、小貯留部３ｓから取り出された湯水が、補助給湯器Ｂにて水質維持温度に加熱される状態で、給湯用循環経路Ｒを通流して、主貯留部３ｍに戻されることにより、給湯用循環経路Ｒの略全長にわたって水質維持温度の湯が通流することになる。
この循環経路水質維持運転は、貯湯槽水質維持運転の後に実行されることにより、貯湯槽水質維持運転の後であって略水質維持温度になっている湯を補助給湯器Ｂにて水質維持温度に加熱する形態で行うので、消費エネルギーを低減することが可能となる。
この貯湯槽水質維持運転の運転時間は短時間であるので、各住戸Ｈにおいて、給湯用循環経路Ｒを通流する湯が使用されても、湯の循環に支障を与える程度にまで小貯留部３ｓの貯留量が少なくなることはない。
【００８０】
〔第３実施形態〕
以下、第３実施形態を説明する。
図１０に示すように、第３実施形態においては、コージェネレーションシステムの構成は、貯湯槽３及び排熱回収用循環手段Ｃ１の構成が異なる以外は、上記の第１実施形態と同様である。
即ち、第１実施形態と同様に、貯湯槽３は、主貯留部３ｍとその主貯留部３ｍよりも横断面積が小さい小貯留部３ｓとを備えて構成してあるが、主貯留部３ｍ及び小貯留部３ｓの具体的な構成が第１実施形態と異なる。
貯湯槽３は、上部が開口した概ね直方体形の箱状の槽形成部材にて開放型に構成し、その槽形成部材の底部の一部分を窪ませて凹部を形成して、その凹部にて小貯留部３ｓを形成し、槽形成部材内における凹部以外の部分を主貯留部３ｍとするようにしてある。
水位センサＬは、主貯留部３ｍから小貯留部３ｓにわたって水位を計測するように設け、槽経由循環路４は、小貯留部３ｓの底部から湯水を取り出して、小貯留部３ｓの上方に対応する主貯留部３ｍの上部に戻すように設けてある。
【００８１】
排熱回収用循環手段Ｃ１は、第１実施形態において設けた分岐経路１０ｂ及び槽湯水循環切換三方弁Ｖ２を省略して、貯湯槽３の小貯留部３ｓの底部から取り出した湯水を排熱回収用熱交換器２を経由して主貯留部３ｍの上部から戻すように流すべく配管した排熱回収用循環経路１０と、その排熱回収用循環経路１０に設けた排熱回収用循環ポンプＰ３とを備えて構成してある。
【００８２】
次に、運転制御部Ｕの制御動作について説明する。
給電制御は第１実施形態と同様であるので説明を省略する。
給湯制御においては、通常貯湯槽湯水循環運転、水補給停止貯湯槽湯水循環運転、給水状態運転、貯湯槽水質維持運転及び水置換運転を、第１実施形態と同様に自動的に実行し、又、操作盤のメンテナンス用運転指令部からの指令に基づいてメンテナンス用運転を実行する。各運転における制御動作は、槽湯水循環切換三方弁Ｖ２の制御動作がない点で異なる以外は、第１実施形態と同様であるので、説明を省略する。
又、各運転におけるエンジン冷却水、貯湯槽３の湯水及び受水槽５の水の流動形態は、貯湯槽水質維持運転における流動形態が異なる以外は第１実施形態と同様であるので、以下、貯湯槽水質維持運転の流動形態における第１実施形態と異なる点を説明して、その他の運転の流動形態の説明は省略する。
即ち、第１実施形態では、貯湯槽３の小貯留部３ｓの湯水が補助給湯器Ｂにて加熱された後、排熱回収用循環経路１０の分岐経路１０ｂを通じて直接小貯留部３ｓに戻されるのに対して、第３実施形態では、貯湯槽３の小貯留部３ｓの湯水が補助給湯器Ｂにて加熱された後、排熱回収用循環経路１０を通じて主貯留部３ｍの上部から小貯留部３ｓに戻される点で、第３実施形態における貯湯槽水質維持運転の流動形態が第１実施形態と異なる。
【００８３】
〔別実施形態〕
次に別実施形態を説明する。
上記の実施形態においては、発電機１を、１日のうちの一部の設定発電時間帯において運転し、その設定発電時間帯以外の非発電時間帯においては停止させる形態で運転させる場合について例示したが、発電機１は、停止させることなく連続して運転させるようにしても良い。この場合は、通常貯湯槽湯水循環運転のみの運転になる。
【００８４】
上記の実施形態においては、貯湯槽３の目標貯留量として、非発電時間帯において消費又は略消費可能な貯留量を設定して、設定発電時間帯においては、貯湯槽３に前記目標貯留量の湯水を貯留すべく槽用給水手段Ｗ１を作動させ、非発電時間帯においては、槽用給水手段Ｗ１を停止させる形態で運転する場合について例示したが、設定発電時間帯と非発電時間帯とを通じて、貯湯槽３に予め設定した設定貯留量の湯水を貯留すべく槽用給水手段Ｗ１を作動させる形態で運転しても良い。この場合も、通常貯湯槽湯水循環運転のみの運転になる。
【００８５】
加熱目標温度は上記の実施形態において例示した温度に限定されるものではなく、種々の温度に設定可能である。例えば、前記通常給湯目標温度設定範囲よりも高い温度の１温度のみを設定しても良い。あるいは、前記通常給湯目標温度設定範囲内の温度に設定しても良いが、省エネを図る上では、前記通常給湯目標温度設定範囲外の温度に設定するのが好ましい。
又、加熱目標温度を前記通常給湯目標温度設定範囲よりも低い温度に設定する場合は、給湯器Ｋを前記水混合後加熱運転にて極力運転させないようにして、省エネを図る上では、前記低設定混合温度以下の温度に設定する。
【００８６】
上記の実施形態においては、熱負荷検出手段として、非発電時間帯中に給湯用循環手段Ｃ２を通じて複数の住戸Ｈに供給される湯水の総熱量を前記非発電時間帯熱負荷として求めるように構成する場合について例示したが、非発電時間帯中に給湯用循環手段Ｃ２を通じて複数の住戸Ｈに供給される湯水の総流量を前記非発電時間帯熱負荷として求めるように構成しても良い。この場合、前記非発電時間帯熱負荷として求めた運転対象サイクルの前のサイクルにおける湯水の総流量を、運転対象サイクルの目標貯留量として設定することになる。
熱負荷検出手段にて検出される前記非発電時間帯熱負荷に基づいて、運転対象サイクルの目標貯留量を設定するに当たって、具体的な設定方法は変更可能である。例えば、毎日検出した前記非発電時間帯熱負荷を月毎に平均して、その平均値を月に対応付けて前記記憶部に記憶させ、その記憶情報に基づいて、運転対象サイクルの目標貯留量を設定するようにしても良い。
【００８７】
上記の実施形態においては、運転対象サイクルの目標貯留量を、熱負荷検出手段にて検出される前記非発電時間帯熱負荷に基づいて変更設定する場合について例示したが、コージェネレーションシステムを設置する対象の地域又は集合住宅の熱負荷を鑑みて、前記目標貯留量を、月に対応付けて、あるいは、月及び曜日に対応付けて予め設定して前記記憶部に記憶させ、その記憶情報に基づいて、運転対象サイクルの前記目標貯留量を、月毎に、あるいは、曜日毎に固定的に設定するようにしても良い。
【００８８】
上記の実施形態においては、給湯用循環経路Ｒは、槽経由循環路４及び槽バイパス路１２を用いて、貯湯槽３を迂回する状態で複数の住戸Ｈを経由する貯湯槽迂回経路を形成するように構成したが、これに代えて、給湯用循環経路Ｒは、槽経由循環路４のみを用いて、貯湯槽３の小貯留部３ｓから取り出した湯水を集合住宅に含まれる複数の住戸Ｈを経由して主貯湯部３ｍの上部に戻す経路を形成するように構成しても良い。
【００８９】
上記の実施形態においては、貯湯槽３を、主貯留部３ｍとその主貯留部３ｍよりも横断面積が小さい小貯留部３ｓとを備えて構成する場合について例示したが、単に一つの貯留部を備えるように構成しても良い。
【００９０】
上記の実施形態においては、貯湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを兼用する補助給湯器Ｂを設ける場合について例示したが、湯槽用補助加熱手段Ｂ１と循環経路用補助加熱手段Ｂ２とを別個に設けても良い。
この場合、貯湯槽水質維持運転の実行中に、給湯用循環経路Ｒを通流する湯水を循環経路用補助加熱手段Ｂ２にて目標加熱温度に加熱しながら給水状態運転を並行して実行することが可能となるので、貯湯槽水質維持運転の実行中にも、目標加熱温度の湯を各住戸Ｈに供給することが可能となる。
【００９１】
各住戸Ｈに設ける給湯器Ｋの構成は変更可能である。例えば、前記循環湯水温度が給湯目標温度よりも低いときは、給湯目標温度よりも設定温度差以上低くなるように設定された前記設定混合温度になるように混合部Ｋｍの混合作動を制御し、且つ、給湯温度が前記給湯目標温度になるように加熱部Ｋｈの加熱作動を制御し、前記循環湯水温度が給湯目標温度以上のときは、加熱部Ｋｈの加熱作動を停止させた状態で、給湯温度が給湯目標温度になるように混合部Ｋｍの混合作動を制御するように構成しても良い。
【００９２】
上記の実施形態においては、給水源として受水槽５を用いる場合について例示したが、給水源として水道そのものを用いても良い。この場合は、槽用給水路９及び循環給水路１４夫々に水道管を接続することになる。
【００９３】
上記の実施形態のように、発電手段を、ガスエンジン等のエンジンにて駆動されるエンジン駆動の回転式の発電機１にて構成する場合、排熱回収用熱交換器２に供給する発電機１の排熱としては、上記の実施形態において例示したエンジン冷却水以外に、エンジンの排ガスを供給したり、エンジン冷却水と排ガスの両方を供給したりするように構成しても良い。尚、発電手段を、エンジン駆動の回転式の発電機１にて構成する場合、エンジンとしては、上記の実施形態において例示した都市ガスを燃料とするもの以外に、ＬＰガス、石油、ガソリン等種々の燃料を用いるものを使用することができる。
又、発電手段は、上記の実施形態において例示した如きエンジン駆動の回転式の発電機１にて構成する以外に、ガスタービンにて駆動するガスタービン駆動の回転式発電機にて構成しても良い。発電手段をガスタービン駆動の回転式の発電機にて構成する場合、排熱回収用熱交換器２には排熱としてガスタービンの排ガスを供給するように構成する。
又、発電手段としては、上記の如き回転式の発電機に限定されるのではなく、例えば、各種の燃料電池にて構成することができる。発電手段を燃料電池にて構成する場合は、排熱回収用熱交換器２には排熱として燃料電池の冷却水を供給するように構成する。
【図面の簡単な説明】
【図１】第１実施形態に係るコージェネレーションシステムの構成、及び、通常貯湯槽湯水循環運転での湯水流動形態を示す図
【図２】第１実施形態に係るコージェネレーションシステムの水補給停止貯湯槽湯水循環運転での湯水流動形態を示す図
【図３】第１実施形態に係るコージェネレーションシステムの給水状態運転及びメンテナンス用運転での湯水流動形態を示す図
【図４】第１実施形態に係るコージェネレーションシステムの貯湯槽水質維持運転での湯水流動形態を示す図
【図５】第１実施形態に係るコージェネレーションシステムの水置換運転での湯水流動形態を示す図
【図６】実施形態に係るコージェネレーションシステムの給湯器の構成を示す図
【図７】第１実施形態に係るコージェネレーションシステムの運転パターンを示す図
【図８】第１実施形態に係るコージェネレーションシステムの運転パターンを示す図
【図９】第２実施形態に係るコージェネレーションシステムの構成、及び、循環経路水質維持運転での湯水流動形態を示す図
【図１０】第３実施形態に係るコージェネレーションシステムの構成を示す図
【図１１】従来のコージェネレーションシステムの構成を示す図
【符号の説明】
１　　発電手段
２　　排熱回収用熱交換器
３　　貯湯槽
５　　給水源
Ｂ２　補助加熱手段
Ｃ１　排熱回収用循環手段
Ｃ２　給湯用循環手段
Ｈ　　住戸
Ｋ　　給湯器
Ｋｈ　加熱部
Ｋｍ　混合部
Ｒ　　給湯用循環経路
Ｕ　　運転制御手段
Ｗ１　槽用給水手段
Ｗ２　循環用給水手段
Ｗ３　住戸用給水手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a power generating means for generating electric power for an area or an apartment house as a power supply target, a heat exchanger for exhaust heat recovery supplied with exhaust heat from the power generating means, and a plurality of dwelling units included in the area or the apartment house. Hot water storage tank for storing hot water as an object, tank water supply means for supplying water to the hot water storage tank, exhaust heat recovery circulation means for circulating hot water between the heat recovery heat exchanger and the hot water storage tank, and the hot water storage tank And a cogeneration system provided with hot water circulation means for circulating hot water in a hot water circulation path extending to the plurality of dwelling units.
[0002]
[Prior art]
Such a cogeneration system heats hot water in a hot water storage tank by exhaust heat generated from the power generating means during operation of the power generating means, and circulates the hot water in the hot water storage tank through a hot water supply circulation path. Can supply hot water to a bath or a kitchen using hot water circulating through a hot water supply circulation path.
By the way, in a set power generation time zone set as a part of the day, the power generation means is operated, and in a non-power generation time period other than the set power generation time zone, the power generation means is stopped. There are cases. In this case, the set power generation time zone is usually set to a time zone where power demand is high as a whole of a plurality of dwelling units included in an area or an apartment house, for example, a time zone from 18:00 to 24:00.
[0003]
In such a cogeneration system, conventionally, as shown in FIG. 11, the hot water of the hot water storage tank 3 circulating in the hot water supply circulation path 84 extending between the hot water storage tank 3 and the plurality of dwelling units is simply heated only by the exhaust heat of the power generation means. (See, for example, Patent Document 1).
In the above-mentioned conventional cogeneration system, as shown in FIG. 11, the hot water storage tank 3 is configured to be closed, and the water supply means W1 for the tank is provided by a water supply channel 81 that supplies water from the tap water to the bottom of the hot water storage tank 3. The exhaust heat recovery circulation means C1 is provided in the exhaust heat recovery flow path 82 that forms a circulation path extending between the hot water storage tank 3 and the exhaust heat recovery heat exchanger 2, and the exhaust heat recovery flow path 82. The hot water circulation means C2 comprises the hot water circulation path 84 and the hot water circulation pump 85 provided in the hot water circulation path 84. In addition, in FIG. 11, K is a water heater provided in each dwelling unit to heat the hot water supplied by the hot water circulation means C2.
[0004]
[Patent Document 1]
JP-A-7-324809
[0005]
[Problems to be solved by the invention]
By the way, in such a cogeneration system, there are times when the power generation unit is maintained or the power generation unit breaks down. In such a case, it becomes impossible to supply exhaust heat from the power generation unit.
However, conventionally, the hot water in the hot water storage tank circulating in the hot water supply circulation path is simply heated only by the exhaust heat of the power generation means. When it became possible, there was a problem that hot water could not be properly supplied to each dwelling unit.
In addition, when the amount of hot water used in a plurality of dwelling units is large, or when the power generation means is started up, or during partial load operation, etc. When the temperature of the hot water drops, it becomes impossible to supply hot water to each dwelling unit properly. Similarly, when operating in a mode in which the power generation means is operated in a set power generation time period that is a part of a day, In the power generation time zone, since the exhaust heat cannot be supplied from the power generation means, there is a problem that the temperature of the hot water in the hot water tank becomes considerably lower than the set power generation time zone, and it becomes impossible to supply hot water appropriately to each dwelling unit. .
The plurality of dwelling units include dwelling units of various living patterns having different hot water usage time periods, and the hot water usage time periods are different for each dwelling unit. If the temperature of hot water changes depending on the time of day, there will be dwelling units that use a lot of hot water when the temperature of the hot water in the storage tank is low, and dwelling units that use a lot of hot water when the temperature of the storage tank is high. This causes a problem that hot water cannot be supplied to a plurality of dwelling units as evenly as possible.
[0006]
The present invention has been made in view of such circumstances, and its purpose is when it is impossible to supply exhaust heat from the power generation means, or when the exhaust heat of the power generation means is insufficient for hot water to be heated, In addition, hot water can be appropriately supplied to each dwelling unit even in a non-power generation time zone, so that a plurality of dwelling units including dwelling units in which the hot water usage time zone is different can be supplied as evenly as possible, and cost reduction is achieved. It is to provide a cogeneration system which can be used.
[0007]
[Means for Solving the Problems]
[Invention of claim 1]
The cogeneration system according to claim 1, wherein the power generation means for generating power for an area or an apartment house as a power supply target, a heat recovery heat exchanger to which waste heat from the power generation means is supplied, the area or the apartment house. A hot water storage tank for storing hot water with a plurality of contained dwelling units as hot water supplies, a tank water supply means for supplying water to the hot water storage tank, and an exhaust heat recovery circulation for circulating hot water over the exhaust heat recovery heat exchanger and the hot water storage tank Means, and a hot water supply circulation means for circulating hot water in a hot water supply circulation path extending between the hot water storage tank and the plurality of dwelling units,
It is characterized in that an auxiliary heating means for heating hot water flowing through the hot water supply circulation path is provided.
That is, the hot water flowing through the hot water supply circulation path can be heated by the auxiliary heating means.
In other words, during maintenance or failure of the power generation means, it becomes impossible to supply the exhaust heat from the power generation means, and it becomes impossible to heat the hot water in the hot water storage tank by the exhaust heat from the power generation means, or When the temperature of the hot water in the hot water storage tank decreases due to insufficient exhaust heat from the power generating means, the auxiliary heating means heats the hot water flowing through the hot water supply circulation path, and In the case where the hot water can be supplied properly and the power generation means is operated in a set power generation time period which is a part of a day, the temperature of the hot water in the hot water storage tank during the non-power generation time period. Even if the temperature is lowered, the hot water flowing through the hot water supply circulation path is heated by the auxiliary heating means, so that each dwelling unit can be appropriately supplied with hot water.
In addition, when the hot water supplied to the dwelling unit in the hot water circulation path is heated by the auxiliary heating means, the hot water flowing through the hot water circulation path is heated by the auxiliary heating means. It becomes possible to simplify the configuration for heating the hot water supplied to the dwelling unit by the route by the auxiliary heating means.
In addition, the hot water circulation originally provided to circulate the hot water through the hot water circulation path by heating the hot water flowing through the hot water circulation path by the auxiliary heating means. By utilizing the function, hot water can be passed through the auxiliary heating means, and the configuration can be simplified.
By the way, when the hot water supplied to the dwelling unit in the hot water supply circulation path is heated by the auxiliary heating means, it is conceivable that the hot water in the hot water storage tank is heated by the auxiliary heating means. It is necessary to connect a flow path for flowing hot and cold water to the heating means to the hot water storage tank and to provide a pump in the flow path, which complicates the configuration.
Incidentally, it is more preferable to provide the auxiliary heating means so as to heat the hot water at an upstream side of a portion passing through each dwelling unit in the hot water supply circulation path, since the hot water can be quickly supplied to each dwelling unit.
In addition, since the installation cost and running cost of the auxiliary heating means constituted by using a gas heating type water heater and the like are shared by a plurality of dwelling units, unequal to each dwelling unit by using the auxiliary heating means. It is natural that there is no giving.
Therefore, when it is not possible to supply exhaust heat from the power generation means, when the exhaust heat of the power generation means is insufficient for the hot and cold water to be heated, and during non-power generation hours, it is possible to supply hot water to each dwelling unit appropriately. As a result, hot water can be supplied as equally as possible to a plurality of dwelling units, including dwelling units with different hot water usage periods, and the cost is reduced by simplifying the configuration for heating the hot and cold water with the auxiliary heating means. A cogeneration system that can achieve this was obtained.
[0008]
[Invention of claim 2]
The cogeneration system according to claim 2 is the cogeneration system according to claim 1, wherein the operation control unit that controls the operation includes the power generation unit in a set power generation time zone that is set as a part of a day. Activating the exhaust heat recovery circulating means and the hot water supply circulating means, and stopping the power generating means and the exhaust heat recovery circulating means during non-power generation time periods other than the set power generation time zone, and In an actuated form, and
In the set power generation time zone and the non-power generation time zone, the configuration is such that the operation is controlled in a form in which the auxiliary heating means is operated so as to heat the hot water flowing through the hot water supply circulation path to a target heating temperature. This is a characteristic configuration.
That is, in the set power generation time zone set as a part of the day, the power generation means, the exhaust heat recovery circulation means and the hot water supply circulation means are operated, and the non-power generation time other than the set power generation time zone In the zone, the power generation means and the exhaust heat recovery circulation means are stopped and the hot water supply circulation means is activated, and in the set power generation time zone and the non-power generation time zone, the auxiliary heating means flows through the hot water supply circulation path. The hot and cold water is heated to the target heating temperature.
In other words, in the set power generation time zone, the hot water in the hot water storage tank is circulated through the hot water supply circulation path in a state where the hot water in the hot water storage tank is heated by the exhaust heat of the power generation means. Since there is no exhaust heat, the hot water in the hot water tank is circulated through the hot water supply circulation path in a state in which the heating of the hot water in the hot water tank by the exhaust heat of the power generation means is stopped, and through the set power generation time zone and the non-power generation time zone. The hot water flowing through the hot water supply circulation path is heated to the target heating temperature by the auxiliary heating means.
Therefore, when the power generation means is operated in a part of the set power generation time period of the day, hot water can be supplied to each dwelling unit at a stable temperature regardless of the time period.
[0009]
[Invention of claim 3]
In the cogeneration system according to claim 3, in claim 2, water supply means for dwelling units that supplies water to each of the plurality of dwelling units is provided,
A mixing unit that mixes hot water supplied through the hot water supply circulating unit with water supplied through the hot water supply unit, and heating the hot water supplied from the mixing unit to each of the plurality of dwelling units; A hot water supply unit for supplying hot water to the hot and cold water demanding unit is provided,
When the temperature of the hot water is lower than the target hot water temperature by a set temperature difference or more, the mixing is performed so that the set mixing temperature is set to be lower than the target hot water temperature by the set temperature difference or more. Controlling the mixing operation of the hot water supply unit and controlling the heating operation of the heating unit so that the hot water supply temperature becomes the hot water supply target temperature, wherein the temperature of the hot water is lower than the temperature lower than the set temperature difference with respect to the hot water supply target temperature. Is also high, in a state where the heating operation of the heating unit is stopped, configured to control the mixing operation of the mixing unit so that the hot water supply temperature becomes the hot water supply target temperature,
It is characterized in that the target heating temperature is set to a temperature outside the set range of the hot water supply target temperature in the water heater.
That is, in the water heater of each dwelling unit, when the temperature of the hot water from the hot water supply circulation path is lower than the target hot water supply temperature by the set temperature difference, the temperature is set so as to temporarily become lower than the target hot water supply temperature by the set temperature difference. Water from the dwelling unit water supply means is mixed with the hot water supplied through the hot water supply circulation means so as to reach the set mixing temperature, and then heated so that the hot water supply temperature becomes the hot water supply target temperature. When the temperature of the hot water from the path is higher than the temperature lower than the set temperature difference with respect to the hot water target temperature, the heating is stopped, and the hot water supplied through the hot water circulating means is adjusted so that the hot water temperature reaches the hot water target temperature. Then, the water from the water supply means for dwelling units is mixed, so that hot water can be supplied at the hot water supply target temperature.
In other words, when the temperature difference between the temperature of hot water from the hot water supply circulation path and the hot water supply target temperature is small, and the heating amount for heating to the target temperature is smaller than a preset minimum heating amount, the hot water supply target temperature It is difficult to heat the hot water, so the water is once mixed in the mixing section, lowered to the set mixing temperature, and then heated to the hot water target temperature in the heating section, thereby stabilizing the hot water temperature. If the temperature of the hot water from the circulation path is higher than the temperature lower than the set temperature difference with respect to the target hot water supply temperature, stop the heating by the heating unit and mix the water to the target hot water supply temperature in the mixing unit. Thus, the time for which the heating section is operated in a heating operation is reduced, and energy saving is achieved, and the hot water supply temperature is stabilized.
In other words, in each dwelling unit, since the hot water supply target temperature is set variously, using hot water supplied through the hot water supply circulation unit, in order to supply hot water at each dwelling unit at the hot water supply target temperature, A water heater having the above-described configuration will be installed.
In such a case, by setting the target heating temperature at which the hot water flowing through the hot water circulation path is heated by the auxiliary heating means to a temperature outside the hot water supply target temperature setting range in the water heater, the hot water circulation is performed. The temperature of the hot and cold water flowing through the route is set as low as possible to a temperature outside the hot water supply target temperature setting range in the water heater, and in the water heater of each dwelling unit, water is once mixed so as to reach the set mixing temperature. Therefore, it is possible to save energy by minimizing the operation in the form of heating so that the hot water supply temperature becomes the hot water supply target temperature (hereinafter, sometimes referred to as a heating operation after mixing water).
Therefore, it is possible to save energy while enabling hot water supply at the hot water supply target temperature using hot water supplied through the hot water circulation means in each dwelling unit.
[0010]
[Invention of claim 4]
According to a fourth aspect of the present invention, in the cogeneration system according to the third aspect, the target heating temperature is set to a temperature lower than the set range, and the target heating temperature for winter used in winter is set to be lower than the set range. A characteristic configuration is that the target temperature is set to a high temperature and is set to a target heating temperature for the summer middle period used at a time other than the winter.
That is, in winter, the hot water flowing through the hot water supply circulation path is heated by the auxiliary heating means to the winter target heating temperature set to a temperature lower than the hot water supply target temperature setting range of the water heater, and in the summer and the intermediate period. The hot water flowing through the hot water supply circulation path is heated by the auxiliary heating means to the target heating temperature for the summer middle period, which is set to a temperature higher than the hot water supply target temperature setting range of the water heater.
That is, in winter, the temperature of the hot water in the hot water tank heated by the exhaust heat of the power generating means is low because the temperature of the hot water supplied to the hot water tank is low. In order to heat the water to a temperature higher than the hot water supply target temperature setting range, a large amount of heat is required, and moreover, the amount of heat radiated from the hot water supply circulation path increases. Therefore, in the winter, by using the auxiliary heating means to heat the hot water flowing through the hot water supply circulation path to the winter target heating temperature lower than the hot water supply target temperature setting range, the water heater of each dwelling unit causes the mixing unit to operate. It is possible to operate the heating section in a heating operation without mixing operation, thereby reducing heat dissipation and minimizing the heating operation after the water mixing, thereby saving energy.
On the other hand, in the summer and the middle period, the temperature of hot water supplied to the hot water tank is high, and the temperature of hot water in the hot water tank heated by the exhaust heat of the power generation means is likely to be high. Alternatively, the hot water flowing through the hot water supply circulation path can be heated to a temperature higher than the hot water supply target temperature setting range with a relatively small amount of heat. Therefore, in the summer and the intermediate period, the hot water flowing through the hot water supply circulation path is heated to the summer intermediate period target heating temperature higher than the hot water supply target temperature setting range by the auxiliary heating means, so that the water heater of each dwelling unit is heated. Is designed to operate in a mode in which the mixing section is operated in a state in which the heating section is not operated to be heated, so that the heating operation after mixing the water is minimized to save energy.
Therefore, it is possible to further save energy while enabling hot water supply at the hot water supply target temperature using hot water supplied through the hot water supply circulation means in each dwelling unit.
[0011]
[Invention according to claim 5]
In the cogeneration system according to claim 5, in any one of claims 2 to 4, a circulating water supply unit that supplies water from a water supply source to the hot water circulation path is provided,
The hot-water supply circulating means circulates the hot-water in the hot-water storage tank in the hot-water supply circulating path, and stops the hot-water supply in the hot-water storage tank. It is configured to be freely switchable to a water supply state for supplying water to the circulation path, and a storage amount that can be consumed or substantially consumed in the non-power generation time zone is set as a target storage amount of the hot water storage tank,
In the state in which the operation control means activates the tank water supply means to store the target amount of hot water in the hot water tank during the set power generation time period, the hot water supply circulation means performs the hot water tank circulation. In the non-power generation time zone, the tank water supply means is stopped, and when the storage amount of the hot water storage tank is larger than a set lower limit storage amount, the hot water supply circulation means is switched to the hot water storage tank. It is operated in a hot water circulation state, and when the storage amount of the hot water storage tank is equal to or less than the set lower limit storage amount, the hot water supply circulation means is configured to operate in the water supply state. I do.
That is, in the set power generation time period, the hot water in the hot water tank is heated by the exhaust heat from the power generation means, and the hot water tank is supplied with water by the water supply means for the tank so that the storage amount of the hot water tank becomes the target storage amount. In this state, the hot water supply circulation means is operated in the hot water tank hot water circulation state, and the hot water in the hot water storage tank is circulated through the hot water supply circulation path. When the water supply is stopped and the storage amount of the hot water tank is larger than the set lower limit storage amount, the hot water circulation means is operated in the hot water tank hot water circulation state, and the hot water of the hot water tank is transferred to the hot water circulation path. When the hot water is circulated and the storage amount of the hot water tank becomes equal to or less than the set lower limit storage amount, the hot water supply circulating means is operated in a water supply state, and the circulation of hot water in the hot water storage tank in the hot water supply circulation path is stopped. Water from the water supply source is supplied to the Through the time zone and the non-power generation time period, the hot water flowing through the hot water circulating passage is heated to a target heating temperature by the auxiliary heating means.
In other words, in the set power generation time zone, the hot water of the hot water tank stored at the target storage amount is heated by the exhaust heat from the power generation means, and the target storage amount is the storage amount that can be consumed or substantially consumed in the non-power generation time period. , The amount of hot water to be heated by the exhaust heat of the power generation means can be made smaller than in a full state, and the hot water in the hot water storage tank can be easily heated to a high temperature. Further, in the non-power generation time period, although the exhaust heat from the power generation means is lost, the supply of water to the hot water tank is stopped, so that it is possible to suppress a decrease in the temperature of the hot water in the hot water tank. Since the storage amount is set to a storage amount that can be consumed or substantially consumed in the non-power generation time zone, operation in the form of heating water from the water supply source by the auxiliary heating means is minimized, or the operation time is minimized. It can be shortened. Thus, the heating amount of the auxiliary heating means for heating to the target heating temperature can be reduced through the set power generation time zone and the non-power generation time zone.
Therefore, when the power generation means is operated in a part of the set power generation time period of the day, it is possible to supply hot water to each dwelling unit at a stable temperature regardless of the time period, and further save energy. Can be planned.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the cogeneration system includes a generator 1 as a power generation unit that generates power for an apartment house as a power supply target, a heat exchanger 2 for recovering exhaust heat to which waste heat from the generator 1 is supplied, Hot water storage tank 3 for storing hot water for a plurality of dwelling units H included in the apartment house, hot water supply means W1 for the water supply to the hot water storage tank 3, exhaust heat recovery heat exchanger 2 and hot water storage tank 3 A circulating means for exhaust heat recovery C1, a circulating means C2 for circulating hot water in a circulating route R for hot water extending between the hot water tank 3 and a plurality of dwelling units H included in the apartment house, and a water receiving tank 5 as a water supply source. Water supply means W2 for supplying water to the hot water supply circulation path R, dwelling unit water supply means W3 for supplying water to each of the plurality of dwelling units H included in the apartment house, and operation for controlling the operation of the cogeneration system. An operation control unit U is provided as control means, and hot water supplied to each hot water demanding unit in the dwelling unit H is supplied to each of the plurality of dwelling units H included in the apartment house using the hot water supplied through the hot water circulation unit C2. The device K is provided.
[0013]
Further, the cogeneration system includes a hot water tank auxiliary heating means B1 for heating hot water in the hot water tank 3, a circulation path auxiliary heating means B2 for heating hot water flowing through the hot water circulation path R, and a generator 1 The auxiliary heat-exchanger 6 is provided to heat the hot and cold water flowing through the hot-water supply circulation path R to which the exhaust heat is supplied.
[0014]
Further, the cogeneration system is provided with a power receiving and transforming facility 62 for collectively receiving power from the commercial power supply 61 and a connection device 63 for system-linking the generator 1 with the commercial power supply 61. The power supply line 64 is wired so as to supply the electric power from the commercial power supply 61 to the electric power consuming equipment in the common area and the electric power consuming equipment of each dwelling unit H included in the apartment house.
[0015]
In addition, the generator 1 is provided with a gas engine (not shown) using city gas supplied through the common part gas supply passage 7 as a fuel, and is configured to be a rotary type driven by the gas engine. is there.
Further, a cooling water circulation path 8 for circulating engine cooling water is provided between the gas engine and the exhaust heat recovery heat exchanger 2. Further, a part of the engine cooling water is diverted and circulated to the auxiliary heating heat exchanger 6. In order to enable this, the cooling water circulation path 8 and the auxiliary heat exchanger 6 are connected via a cooling water flow three-way valve V1 via a branch circulation path 8b, and the cooling water circulation path 8 is provided with a cooling water circulation pump P1. It is. By operating the cooling water circulation pump P1, the engine cooling water is circulated through the gas engine, the exhaust heat recovery heat exchanger 2 and the auxiliary heating heat exchanger 6, respectively.
[0016]
The tank water supply means W1 includes a tank water supply path 9 for supplying water from the water receiving tank 5 to the hot water storage tank 3, and a tank water supply pump P2 provided in the tank water supply path 9.
When the tank water supply pump P2 is operated, the tank water supply means W1 is operated, the stored water in the water receiving tank 5 is supplied to the hot water storage tank 3 through the tank water supply passage 9, and the tank water supply pump P2 is stopped. Then, the operation of the tank water supply means W1 is stopped.
Tap water is supplied to the water receiving tank 5, and although not described in detail and illustrated, supply of tap water is intermittently performed so that the stored water level of the water receiving tank 5 becomes the set water level.
[0017]
The hot water storage tank 3 includes a main storage section 3m and a small storage section 3s having a smaller cross-sectional area than the main storage section 3m. The main storage section 3m and the small storage section 3s communicate with each other to store hot water. When the storage amount of the tank 3 is equal to or smaller than the set lower limit storage amount, the entire amount is stored in the small storage unit 3s. When the storage amount of the hot water storage tank 3 is larger than the set lower limit storage amount, the set lower limit storage amount is set in the small storage unit 3s. The main storage unit 3m is provided so that the amount stored and exceeding the set lower limit storage amount is stored in the main storage unit 3m. Incidentally, the set lower limit storage amount is set to, for example, about 10% of the storage amount of the hot water storage tank 3 in a full state.
[0018]
Specifically, an open-type main storage unit 3m having an open upper part and a closed small storage unit 3s having a smaller cross-sectional area than the main storage unit 3m are separate from each other, and the small storage unit 3s is It is provided below the bottom of the main storage part 3m, and the bottom of the main storage part 3m and the upper part of the small storage part 3s are communicated by the communication passage 3c.
A water level sensor L is provided in the main storage section 3m of the storage tank 3.
[0019]
The exhaust heat recovery circulating means C1 is arranged to flow hot water taken out from the bottom of the small storage section 3s of the hot water tank 3 through the exhaust heat recovery heat exchanger 2 and back from the upper part of the main storage section 3m. Exhaust heat recovery circulation path 10, a branch path 10b that branches from a portion of the exhaust heat recovery circulation path 10 downstream of exhaust heat recovery heat exchanger 2 and returns hot water to small storage section 3s, and a branch thereof. The system is provided with a tank water / water circulation switching three-way valve V2 provided in the portion, and an exhaust heat recovery circulation pump P3 provided in the exhaust heat recovery circulation path 10. That is, when the exhaust heat recovery circulation pump P3 is operated, the exhaust heat recovery circulation means C1 is operated. When the operation of the exhaust heat recovery circulation pump P3 is stopped, the exhaust heat recovery circulation means C1 is activated. By stopping, and by switching the three-way valve V2 for switching between the tank hot and cold water, the return path of the exhaust heat recovery circulation path 10 (the flow path connected to the outlet of the exhaust heat recovery heat exchanger 2) is passed. It is configured to be freely switchable between a normal circulation state in which the flowing hot and cold water is returned to the main storage section 3m, and a circulation state at the time of tank heating in which the hot and cold water flowing through the return path portion of the exhaust heat recovery circulation path 10 is returned to the small storage section 3s. It is.
[0020]
The hot water supply circulation means C2 includes a hot water supply circulation path R extending between the hot water storage tank 3 and a plurality of dwelling units H included in the apartment house, an upstream circulation pump P4 and a downstream circulation pump P5 provided in the hot water supply circulation path R. Each dwelling unit H is connected to a dwelling unit hot water supply channel 11 that supplies hot water flowing through the hot water supply circulation path R to each dwelling unit H, and each dwelling unit hot water supply channel 11 is connected to each dwelling unit H. A hot water supply amount sensor Q3 for each dwelling unit for detecting a flow rate of hot water supplied to the house is provided.
[0021]
The hot water supply circulation route R will be described. A pipe is provided to flow hot water taken out from the small storage section 3s of the hot water storage tank 3 so as to return to the upper part of the main hot water storage section 3m via a plurality of dwelling units H included in the apartment house, and a circulation path 4 through the tank is provided. A tank return stop three-way valve V3 is provided on the downstream side of the passage through the dwelling unit in the circulation path 4 through the tank, and the tank return stop three-way valve V3 and the upstream of the passage through the dwelling unit in the circulation path 4 through the tank are bypassed. In addition, a check valve 13 is provided on the upstream side of the connection point of the tank bypass line 12 in the circulation path 4 through the tank, and the three-way valve V3 for returning to the tank is switched. The tank can be switched between a tank return state in which the hot water flowing through the hot water 4 flows into the hot water storage tank 3 and a tank return stop state in which the hot water flowing through the hot water circulation path 4 stops flowing into the hot water storage tank 3. It is composed.
The upstream circulation pump P4 is provided on the upstream side of the connection point of the tank bypass passage 12 on the upstream side of the location via the dwelling unit in the circulation path 4 via the tank, and the downstream circulation pump P5 is provided via the dwelling unit on the circulation path 4 via the tank. It is provided downstream of the location and upstream of the tank return stop three-way valve V3.
[0022]
When the tank return stop three-way valve V3 is switched to the tank return stop state and the upstream circulation pump P4 and the downstream circulation pump P5 are operated, the hot water taken out of the hot water storage tank 3 passes through the tank circulation path 4. It flows through a plurality of dwelling units H, and further circulates in a hot water tank bypass route which returns from the tank return stop three-way valve V3 to the tank bypass channel 12 and returns to the tank via channel 4 to return to the hot water tank bypass route. As the hot water flowing through the hot water tank is used in each dwelling unit H, the hot water in the hot water tank 3 is replenished to the hot water tank bypass path by the upstream circulation pump P4.
In other words, the hot water supply circulation path R extending between the hot water storage tank 3 and the plurality of dwelling units H is a hot water storage tank passing through the plurality of dwelling units H in a state of bypassing the hot water storage tank 3 using the circulation path 4 via the tank and the bypass path 12. The hot water supply circulation means C2 is configured to form a detour path, and is configured to circulate through the hot water supply circulation path R while refilling the hot water in the hot water storage tank 3 into the hot water supply circulation path R.
[0023]
In addition, an auxiliary heating heat exchanger 6 is provided on the downstream side of the place passing through the dwelling unit and on the upstream side of the three-way valve V3 for stopping the tank return in the circulation path 4 via the tank. The hot water flowing through the hot water supply circulation path R is heated. That is, the hot water flowing through the hot water supply circulation route R is heated by the exhaust heat of the generator 1 in the auxiliary heating heat exchanger 6 so as to suppress a temperature decrease due to heat radiation.
[0024]
The water supply means for circulation W2 is connected downstream of the connection point of the tank bypass 12 on the upstream side of the passage through the dwelling unit in the circulation path 4 via the tank, and supplies water from the water receiving tank 5 to the circulation path R for hot water supply. And a water supply switching three-way valve V4 provided at a connection portion of the circulation water supply path 14 in the circulation path 4 via the tank, and a circulation and dwelling water supply pump P6 provided in the circulation water supply path 14. It is.
That is, the flow of hot water from the hot water storage tank 3 is stopped by the water supply switching three-way valve V4, and a water supply path connection state in which water is supplied from the circulation water supply path 14 to the circulation path R for hot water supply, and water supply from the circulation water supply path 14 is supplied. It is configured to be able to stop and switch to a water supply channel cutoff state in which hot water from hot water storage tank 3 flows.
[0025]
Further, a dwelling water supply channel 15 is branched from the circulating water supply channel 14, and the dwelling unit water supply channel 15 is piped so as to supply water to each of the plurality of dwelling units H. The dwelling unit water supply means W3 includes a circulating water supply channel. 14 and a water supply channel 15 for dwelling units and a water pump P6 for circulation and dwelling units.
[0026]
An auxiliary water heater B is provided which also serves as the auxiliary heating means B1 for the hot water tank and the auxiliary heating means B2 for the circulation path.
The auxiliary water heater B is constituted by a gas-fired instantaneous water heater. Specifically, first and second two heat exchangers 71 and 72 and the first and second heat exchangers 71 and 72 are provided. , 72, and a blower 74 for passing combustion air through the gas burner 73.
At the inlet of the first heat exchanger 71, there is provided a first water supply amount sensor Q1 for detecting the flow rate of hot water supplied to the first heat exchanger 71, and at the outlet of the first heat exchanger 71, A first tapping temperature sensor T1 for detecting a temperature of tapping water from the first heat exchanger 71 is provided, and a flow rate of tapping water supplied to the second heat exchanger 72 is provided at an inlet of the second heat exchanger 72. A second water supply amount sensor Q2 for detection is provided, and a second tapping temperature sensor T2 for detecting the temperature of tap water from the second heat exchanger 72 is provided at an outlet of the second heat exchanger 72.
The gas burner 73 is connected to the gas supply passage 7 for the common part. The gas supply passage 7 for the common part has a gas interrupting valve 75 for interrupting the gas supply and a gas proportional valve 76 for adjusting the gas supply amount. Is provided.
[0027]
The operation of the auxiliary water heater B is performed by the operation control unit U, and the operation control unit U supplies hot water to at least one of the first heat exchanger 71 and the second heat exchanger 72, Based on the fact that the detected hot water flow rate of at least one of the water supply amount sensor Q1 and the second water supply amount sensor Q2 is equal to or greater than a set amount, the blower 74 is operated and the gas intermittent valve 75 is opened, and a spark plug (not shown) is opened. Is operated to ignite the gas burner 73, and the combustion amount is adjusted by adjusting the opening of the gas proportional valve 76 as described later, so that the detected hot water flow rates of both the first water supply amount sensor Q1 and the second water supply amount sensor Q2 are reduced. When the amount becomes smaller than the set amount, the gas intermittent valve 75 is closed to extinguish the gas burner 73, and then the blower 74 is stopped.
[0028]
Then, the hot water flowing through the hot water circulation path R flows through the first heat exchanger 71, and then returns to the hot water circulation path R, and is supplied to each dwelling unit H such that the dwelling unit of the bath circulation path 4 The first heat exchanger 71 is connected to the upstream side of the via-portion via the auxiliary heating channel 16, and the connecting portion between the tank-using circulation channel 4 and the auxiliary heating channel 16 is provided with the tank-using circulation channel 4. An auxiliary heating switching three-way valve V5 is provided for switching between an auxiliary heating state in which the flowing hot and cold water flows through the first heat exchanger 71 and an auxiliary heating stop state in which the flowing hot and cold water does not flow.
A hot water tank take-out temperature sensor T3 for detecting the temperature of hot water taken out of the hot water tank 3 is provided at a location on the upstream side of the connection point with the auxiliary heating channel 16 in the circulation path 4 through the tank. A dwelling unit supply temperature sensor T4 for detecting the temperature of hot and cold water supplied to each dwelling unit H is provided on the upstream side of the dwelling unit location and on the downstream side of the connection location of the auxiliary heating channel 16.
[0029]
Also, the hot and cold water flowing through the outward path portion (flow path portion connected to the inlet of the exhaust heat recovery heat exchanger 2) in the exhaust heat recovery circulation path 10 is bypassed to the exhaust heat recovery heat exchanger 2, After flowing through the second heat exchanger 72, the exhaust heat recovery is performed so as to return to the return path portion (the flow path portion connected to the outlet of the exhaust heat recovery heat exchanger 2) in the exhaust heat recovery circulation path 10. The circulation path 10 for water and the second heat exchanger 72 are connected by a channel 17 for raising the temperature of the bath. A hot-water storage tank-side tank temperature switching three-way valve V6 for switching between a waste heat recovery state in which heat is passed through the heat recovery heat exchanger 2 and a tank heating state in which hot water is passed through the second heat exchanger 71; A bath P7 is provided in the bath 17. Further, a small storage for detecting the temperature of hot water taken out from the small storage section 3s of the hot water tank 3 at a position upstream of the three-way valve V6 of the hot water tank on the outward path in the exhaust heat recovery circulation path 10. A part take-out temperature sensor T5 is provided.
[0030]
Further, the hot and cold water flowing through the outward path portion (portion connected to the inlet of the second heat exchanger 72) in the tank temperature increasing flow path 17 is divided and passed through the first heat exchanger 71, In order to return to the return path portion (portion connected to the outlet of the second heat exchanger 72) in the temperature increasing flow path 17, the tank temperature increasing flow path 17 and the auxiliary heating flow path 16 are divided by the branch flow path 18. The first heat exchanger 71 is connected to each of the connecting portions of the auxiliary heating flow path 16 and the branch flow path 18, in which the first heat exchanger 71 allows hot water to flow from the hot water supply circulation path R, and the first heat exchange. The water heater-side tank temperature switching three-way valve V7 is provided in the water heater 71 for switching to a tank temperature rising state in which hot water from the tank temperature raising flow path 17 flows.
[0031]
When the tank return stop three-way valve V3 is switched to the tank return stop state and the water supply switching three-way valve V4 is switched to the water supply path cutoff state, the upstream circulation pump P4 and the downstream circulation pump P5 are operated. A hot water tank hot water circulation state in which hot water in hot water storage tank 3 is circulated through hot water supply circulation path R is obtained.
In addition, the tank return stop three-way valve V3 is switched to the tank return stop state, the water supply switching three-way valve V4 is switched to the water supply path connection state, and the upstream circulation pump P4 and the downstream circulation pump P5 are stopped. When the circulation / dwelling unit water supply pump P6 is operated, a water supply state is provided in which water from the water receiving tank 5 as a water supply source is supplied to the hot water circulation path R.
Further, the three-way valve V4 is switched to the water supply path connection state, the three-way valve V5 is switched to the auxiliary heating stop state, the tank return stop three-way valve V3 is switched to the tank return state, and the upstream circulation is performed. When the circulation / dwelling unit water supply pump P6 is operated for the set water replacement time while the pump P4 and the downstream side circulation pump P5 are stopped, the circulation of the hot water in the hot water storage tank 3 is stopped, and the water supply as a water supply source is stopped. The water from the water tank 5 is caused to flow so as to be supplied to the hot water storage tank 3 through the circulation path R for hot water supply, and the hot water in the circulation path R for hot water is supplied by the circulation water supply means W2 over substantially the entire length of the circulation path R for hot water supply. The water is replaced with the supplied water.
That is, the hot water supply circulation means C2 is configured to be switchable between the hot water storage tank hot water circulation state, the water supply state, and the water replacement state.
[0032]
Further, with the hot-water supply circulating means C2 switched to the hot-water storage tank hot-water circulation state, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating state, and the water heater side tank heating switching three-way valve V7 is switched to the auxiliary heating state. When the burner 73 is burned, the hot water flowing through the hot water supply circulation path R can be heated by the first heat exchanger 71.
Further, the three-way valve V2 for switching the tank hot water circulation is switched to the circulating state at the time of the tank heating, and the three-way valve V6 for switching the tank heating tank temperature and the three-way valve V7 for switching the tank heating tank temperature are respectively switched to the tank heating state. By operating the exhaust heat recovery circulation pump P3 and the tank temperature raising pump 7 to burn the burner 73, the hot and cold water in the small storage section 3s flows through the first and second heat exchangers 71 and 72. It can be circulated in a state where it is made to be heated.
[0033]
Each dwelling unit H is connected to a dwelling unit gas supply passage 19 for supplying city gas.
Then, in each dwelling unit H, the dwelling unit gas supply path 19, the dwelling unit hot water supply path 11 and the dwelling unit water supply path 15 branched from the hot water supply circulation path R are connected to the water heater K, and the water heater K is used. The hot water supply unit is configured to supply hot water using hot water supplied through the hot water supply circulation unit C2 and water supplied through the dwelling unit water supply unit W3.
[0034]
Next, the water heater K provided in each dwelling unit H will be described with reference to FIG.
The water heater K has a mixing section Km for mixing hot water supplied from the hot water supply path 11 for dwelling units and water supplied from the hot water supply path 15 for dwelling units, and heating in which hot water is supplied from the mixing section Km as a heating target. And a remote control operation section 31 including a hot water supply temperature setting section for setting a hot water supply target temperature.
[0035]
The heating unit Kh heats the hot water supplied from the mixing unit Km through the water supply passage 32, and flows through the hot water supply heat exchanger 34 that supplies the heated hot water to the hot water supply passage 33, and flows through the additional heating circulation passage 35. The operation of the additional heat exchanger 36 for heating the hot and cold water in the bathtub (not shown) to be heated, the gas burner 37 for heating the hot water supply heat exchanger 34 and the additional heat exchanger 36, and the operation of the heating unit Kh are controlled. It comprises a heating control section 38 and the like.
[0036]
The gas burner 37 is connected to the gas supply passage 19 for dwelling units, and the gas supply passage 19 for dwelling units is provided with a gas interrupting valve 39 for interrupting gas supply and a gas proportional valve 40 for adjusting the gas supply amount. is there.
[0037]
The water supply path 32 is provided with a water supply temperature sensor 41 for detecting the temperature of the supplied hot water, and a water supply amount sensor 42 for detecting the flow rate of the supplied hot water. The water supply path 32 and the hot water supply path 33 are connected to the water supply bypass path 43. Connected.
The hot water supply path 33 includes, in order from the upstream side, a mixing valve 45 for adjusting a mixing ratio of hot water from the hot water supply heat exchanger 34 and water from the hot water supply bypass path 43, and a water proportional valve 50 for adjusting the amount of hot water. A hot water supply temperature sensor 44 for detecting the temperature of the hot and cold water mixed by the mixing valve 45 is provided, and a hot water tap 49 is connected to the tip of the hot water supply passage 33.
A hot-water path 46 branched from the hot-water supply path 33 is connected to the outward path in the additional heating circulation path 35, and the hot-water path 46 is provided with a hot-water opening / closing valve 47.
In addition, a bathtub circulation pump 48 for circulating bathtub water is provided in a return path portion of the additional heating circulation path 35.
[0038]
The mixing unit Km determines the mixing ratio of hot water supplied from the hot water supply channel 11 for dwelling units (that is, the hot water circulation means C2) to water supplied from the dwelling unit water supply channel 15 (that is, dwelling unit water supply means W3). The mixing valve 51 to be adjusted, the hot water supply path opening / closing valve 52 for intermittently supplying hot water from the hot water supply path 11 for the dwelling unit to the mixing valve 51, and the temperature of hot water supplied to the mixing valve 51 from the hot water supply path 11 for the dwelling unit ( Hereinafter, a circulating hot water temperature sensor 53 for detecting the circulating hot water temperature) and a temperature of the water supplied to the mixing valve 51 from the dwelling unit water supply passage 15 (sometimes referred to as a mixing portion water supply temperature) are detected. The operation of the mixing section Km is controlled by a supply water temperature sensor 54, a mixing temperature sensor 55 for detecting the temperature of the hot and cold water flowing out of the mixing valve 51 (hereinafter sometimes referred to as a mixed hot and cold water temperature). It is constituted comprising a coupling control unit 56 or the like.
[0039]
Next, control operations of the heating control unit 38 and the mixing control unit 56 will be described.
The heating control unit 38 is configured to communicate various types of control information with the remote control operation unit 31 and the mixing control unit 56, respectively.
When the operation switch of the remote control operation unit 31 is turned on, the heating control unit 38 and the mixing control unit 56 can be controlled individually, and the hot water supply path opening / closing valve 52 is in an operable state.
Then, when the hot water tap 49 is opened and the flow rate of the hot water detected by the water supply amount sensor 42 becomes equal to or more than the set amount, the heating control unit 38 instructs the mixing control unit 56 to set the hot water supply target set by the remote control operation unit 31. The temperature is transmitted, and the mixing control unit 56 compares the circulating hot water temperature detected by the circulating hot water temperature sensor 53 with the hot water supply target temperature sent from the heating control unit 38, and determines the circulating hot water temperature as the hot water supply target temperature. If the temperature is higher than the temperature lower than the set temperature difference Δt (hereinafter, may be referred to as the non-combustion control temperature), the fact is indicated that the circulating hot water temperature is lower than the target hot water supply temperature by the set temperature difference Δt or more. In the case of (hereinafter, sometimes referred to as a combustion control temperature), this is transmitted to the heating control unit 38, respectively.
Further, the mixing control section 56 sets and stores a preset mixing temperature in advance.
[0040]
The set temperature difference Δt is a temperature difference corresponding to a state in which the combustion amount of the gas burner 37 required for heating the hot water to be heated to the hot water supply target temperature is larger than the minimum combustion amount of the gas burner 37 (details will be described later). The set temperature difference Δt is a normal temperature corresponding to the case where the target hot water supply temperature set by the remote control operation unit 31 is within a preset normal hot water supply target temperature range (for example, 37 to 44 ° C.). The set temperature difference Δt (for example, 2 ° C.) for the hot water supply target temperature and the high temperature corresponding to the case where the hot water supply target temperature set by the remote control operation unit 31 is a preset high temperature hot water supply target temperature (for example, 60 ° C.) A set temperature difference Δt (for example, 3 ° C.) for the hot water supply target temperature is set.
The set mixed temperature is set so as to be lower than the set hot water supply target temperature by the set temperature difference Δt or more. As the set mixed temperature, the set hot water supply target temperature set by the remote control operation section 31 is within the range of the normal hot water supply target temperature range. And a low set mixed temperature (for example, 30 ° C.) set to a temperature lower than the normal hot water supply target temperature range by a set temperature difference Δt or more, and a hot water supply target temperature set by the remote control operation unit 31. Two types are set: a high setting mixed temperature (for example, 45 ° C.) corresponding to the high temperature hot water supply target temperature.
[0041]
When the hot water tap 49 is opened and the hot water supply target temperature is transmitted from the heating control unit 38 based on the detected hot water flow rate of the water supply amount sensor 42 being equal to or greater than the set amount, the mixing control unit 56 sets the circulating hot water temperature. The circulating hot water temperature detected by the sensor 53 is compared with the hot water supply target temperature, and when the circulating hot water temperature is the non-combustion control temperature, the circulating hot water temperature sensor 53, the feed water temperature sensor 54, and the mixing temperature sensor 55, respectively. The mixing control is performed to adjust the mixing valve 51 so that the mixed hot water temperature detected by the mixed temperature sensor 55 becomes the hot water supply target temperature based on the detected temperature of the hot water and the hot water from the hot water supply passage 11 for dwelling units. The water from the dwelling unit water supply passage 15 is mixed, and the fact that the circulating hot water temperature is the non-combustion control temperature is transmitted to the heating control unit 38.
When the mixing controller 56 sends the notification that the circulating water temperature is the non-combustion control temperature, the heating controller 38 sets the gas burner 37 to the combustion stopped state.
Therefore, the hot and cold water supplied from the mixing section Km to the heating section Kh flows out of the hot water tap 49 without being heated by the heating section Kh. Take a bath.
[0042]
For example, when the hot water supply target temperature is set to 40 ° C., the circulating hot water temperature is higher than the set temperature difference Δt than the target hot water supply temperature of 40 ° C., that is, higher than 38 ° C., which is 2 ° C. lower, The non-combustion control temperature is reached. In the range where the temperature of the circulating hot water is higher than 38 ° C. and 40 ° C. or lower, the hot water from the hot water supply passage 11 for dwelling units is directly discharged without mixing the water from the water supply passage 15 for dwelling units, When the circulating hot water temperature is higher than 40 ° C., the hot water from the hot water supply channel 11 for dwelling is mixed with the water from the hot water supply channel 15 for dwelling so that the mixed hot water temperature becomes the hot water supply target temperature. .
[0043]
On the other hand, when the circulating water temperature is the combustion control temperature, the mixed water temperature detected by the mixing temperature sensor 55 is determined based on the detected temperatures of the circulating water temperature sensor 53, the feedwater temperature sensor 54, and the mixing temperature sensor 55. The mixing valve 51 is adjusted such that the hot water supply target temperature is in the normal hot water supply target temperature range and is set to the low set mixed temperature, or the hot water supply target temperature is set to the high set mixed temperature when the hot water supply target temperature is high. The mixing control is executed to mix the hot water from the hot water supply channel 11 for the dwelling unit with the water from the hot water supply channel 15 for the dwelling unit, and transmit to the heating control unit 38 that the circulating hot water temperature is the combustion control temperature. .
When the mixing controller 56 sends the notification that the temperature of the circulating water is the temperature for combustion control, the heating controller 38 burns the gas burner 37, the target hot water supply temperature, the temperature detected by the water supply temperature sensor 41, and the water supply amount sensor. Feedforward control for adjusting the opening of the gas proportional valve 40 and the opening of the mixing valve 45 so that the temperature of the hot water flowing out of the hot water supply heat exchanger 34 becomes the hot water supply target temperature based on the detected water supply amount at 42. And performs a feedback control for finely adjusting the opening of the gas proportional valve 40 based on the deviation between the detected temperature of the hot water supply temperature sensor 44 and the target hot water supply temperature.
Therefore, hot water at the hot water supply target temperature flows from the hot water tap 49.
[0044]
For example, when the hot water supply target temperature is set to 40 ° C., when the circulating hot water temperature is equal to or lower than 38 ° C. which is lower than the target temperature of 40 ° C. by the set temperature difference Δt, that is, 2 ° C. or less. It becomes the temperature for combustion control. Then, in the mixing section Km, the water from the dwelling unit water supply path 15 is mixed with the hot water from the dwelling unit hot water supply path 11 so that the mixed hot water temperature becomes a low set mixing temperature (for example, 30 ° C.). At Kh, it is heated to the hot water supply target temperature of 40 ° C. and the hot water is discharged.
[0045]
That is, when the circulating hot water temperature is lower than the target hot water temperature by the set temperature difference Δt or more, the water heater K is set to the set mixed temperature set to be lower than the target hot water temperature by the set temperature difference Δt or more. And the heating operation of the heating section Kh is controlled so that the hot water supply temperature becomes the hot water supply target temperature, and the circulating hot water temperature is lower than the target hot water supply temperature by a set temperature difference Δt. When the temperature is higher than the temperature, the mixing operation of the mixing section Km is controlled such that the hot water supply temperature becomes the hot water supply target temperature in a state where the heating operation of the heating section Kh is stopped.
[0046]
When the temperature of the hot water from the hot water circulation means C2 is the combustion control temperature, the hot water and the hot water from the hot water circulation means C2 are adjusted so that the set mixing temperature can be stably adjusted to the hot water supply target temperature. The water from the dwelling unit water supply means W3 is mixed and then heated to the hot water supply target temperature in the heating unit Kh, so that the difference between the temperature of the hot water from the hot water supply circulation means C2 and the target hot water supply temperature is reduced. Even when the temperature is small, hot or cold water having a target hot water supply temperature or a substantially hot water supply target temperature can be obtained.
That is, in order to secure the combustion stability of the gas burner 37, the combustion amount of the gas burner 37 is not reduced to a value smaller than the predetermined minimum combustion amount. Therefore, when the above-described hot water mixing control, that is, the control for mixing the hot water from the hot water circulation means C2 and the water from the dwelling water supply means W3 to the set mixing temperature is not performed, the hot water circulation means is not used. When the difference between the temperature of the hot water from C2 and the hot water supply target temperature is small and the combustion amount obtained based on the difference is smaller than the minimum combustion amount, for example, the gas burner 37 is burned at the minimum combustion amount. Therefore, there arises a problem that it is difficult to adjust the temperature of hot water to be supplied to the hot water supply target temperature. Therefore, by performing the hot and cold water mixing control as described above, the above-described problem can be solved.
[0047]
Next, the operation control unit U will be described.
The operation control unit U activates the generator 1, the exhaust heat recovery circulating unit C1, and the hot water circulating unit C2 in a set power generation time period set as a part of a day, and the set power generation is performed. In a non-power generation time zone other than the time zone, the generator 1 and the exhaust heat recovery circulation means C1 are stopped and the hot water supply circulation means C2 is operated, and in the set power generation time zone and the non-power generation time zone, The operation is controlled by heating the auxiliary water heater B so that the hot water flowing through the hot water circulation path R is heated to the target heating temperature.
In addition, the operation control unit U sets the target storage amount of the hot water storage tank 1 to a storage amount that can be consumed or substantially consumed in the non-power generation time period, and the operation control unit U sets the target storage amount in the hot water storage tank 1 in the set power generation time period. In a state where the tank water supply means W1 is operated to store an amount of hot water, the hot water circulation means C2 is operated in the hot water circulation state, and the tank water supply means W1 is stopped during the non-power generation time zone. In this state, when the storage amount of the hot water storage tank 3 is larger than the set lower limit storage amount, the hot water supply circulation means C2 is operated in the hot water storage tank hot water circulation state, and the storage amount of the hot water storage tank 3 is set to the set lower limit storage amount. In the following cases, the hot water supply circulating means C2 is configured to operate in the water supply state.
[0048]
In the storage unit built in the operation control unit U, the set power generation time zone, the set lower limit water level that is the water level of the hot water tank 3 corresponding to the set lower limit amount, the water quality maintaining temperature, and the hot water tank water quality maintaining operation are continued. The preset water quality maintenance operation time to be executed, the set water replacement time, and the target heating temperature for heating the hot water flowing through the hot water circulation path R in the auxiliary water heater B are set and stored in advance. It is.
By the way, as the set power generation time zone, two types, one for the summer season and one for the winter season, are set and stored. The set power generation time zone for the summer middle period is a time zone where power demand is high. The set power generation time zone for winter is set to be from 24 hours to 24 o'clock, and the set power generation time zone for winter is longer than the set power generation time zone for winter, so as to respond to the heat demand since the heat demand is larger than in summer. The time zone is set from hour to 23:00. A time period (24 hours) obtained by adding the set power generation time period and the non-power generation time period is referred to as one cycle.
[0049]
Since the set lower limit storage amount is set to the storage amount in the full storage state in the small storage unit 3s, the set lower limit water level is set to a water level at which the water level of the main storage unit 3m becomes zero. That is, when the water level of the hot water storage tank 3 is at the set lower limit water level, the entire amount of hot water can be stored in the small storage section 3s and not in the main storage section 3m.
[0050]
The water quality maintenance temperature is set to, for example, 60 ° C., and the set water quality maintenance operation time is set to, for example, one hour.
The set water replacement time is such that the water in the water receiving tank 5 that has flowed into the hot water supply circulation path R when the three-way water supply switching valve V4 is switched to the water supply path connection state flows through the hot water supply circulation path R, and enters the hot water storage tank 3. On the other hand, the time is set to be longer than the time required for outflow.
[0051]
The target heating temperature is set to a temperature outside the set range (for example, 37 to 44 ° C.) of the normal hot water supply target temperature that can be set by the remote control operation section 31 of the water heater K provided in each dwelling unit H.
The target heating temperature is set lower than the normal hot water supply target temperature setting range and at the same temperature (for example, 30 ° C.) as the low set mixing temperature, and is used in winter (for example, from December to February). The target heating temperature for winter and the target heating temperature for summer middle period which are set to a temperature (for example, 45 ° C.) higher than the normal hot water supply target temperature setting range and are used in periods other than winter are stored.
[0052]
Further, a heat load detecting means for detecting, as a heat load, a heat amount of hot water supplied to the plurality of dwelling units H included in the apartment house by the hot water supply circulating means C2 is provided, and the heat load detecting means detects the heat amount. The heat load in the power generation time zone (hereinafter, may be simply referred to as a non-power generation time zone heat load) is configured to be stored in the storage unit, and the operation control unit U is stored in the storage unit. The target storage amount of the operation target cycle is set based on the storage information of the non-power generation time period heat load.
[0053]
Specifically, the operation control means U determines the detected flow rate of each dwelling unit-based hot water supply amount sensor Q3 over the non-power generation time period based on the detection information of each dwelling unit-based hot water supply amount sensor Q3 and the dwelling unit supply temperature sensor T4. The total amount of hot and cold water is multiplied by the detected temperature of the dwelling unit supply temperature sensor T4 to calculate the amount of heat, the amount of heat is integrated, the integrated amount of heat is obtained as the non-power generation time period heat load, and The stored non-power generation time period heat load storage information is rewritten to the newly obtained non-power generation time period heat load heat. That is, the heat load detecting means is constituted by the dwelling unit-based hot water supply amount sensor Q3 and the dwelling unit supply temperature sensor T4.
Then, the operation control unit U performs the non-power generation time period heat load stored in the storage unit, that is, the non-power generation time period heat load in a cycle before the operation target cycle, based on the non-power generation time period heat load. It is configured to set a target storage amount.
[0054]
Hereinafter, the control operation of the operation control unit U will be separately described into power supply control for supplying power to the common unit and each dwelling unit H and hot water supply control for supplying hot water to each dwelling unit.
First, the control operation of the power supply control will be described.
The operation control unit U operates the generator 1 and the cooling water circulation pump P1 during the set power generation time period, and stops the generator 1 and the cooling water circulation pump P1 during non-power generation time periods other than the set power generation time period. In this manner, the generator 1 is automatically operated every day.
During the operation of the generator 1, power is supplied to the power consuming devices of the common part and the power consuming devices of each dwelling unit H by the generator 1, and the output of the generator 1 is supplied to the power consuming devices. Is insufficient, the shortage is supplemented by the commercial power supply 61.
Further, while the generator 1 is stopped, power is supplied from the commercial power supply 61 to the power consuming devices in the common part and the power consuming devices in each dwelling unit H.
During operation of the generator 1, the engine cooling water circulates through the heat exchanger for exhaust heat recovery 2 and the heat exchanger for auxiliary heating 6, thereby cooling the gas engine and reducing the exhaust heat thereof. The heat is supplied to the exhaust heat recovery heat exchanger 2 and the auxiliary heating heat exchanger 6.
[0055]
Next, hot water supply control will be described with reference to FIGS. In FIGS. 1 to 5, each flow path portion where hot water and engine cooling water flow is indicated by a thick line.
The circulation / dwelling unit water supply pump P6 is constantly operated so that the water in the water receiving tank 5 can be constantly supplied to each dwelling unit H through the dwelling unit water supply channel 15. Description of the operation control of the water supply pump P6 is omitted.
[0056]
At the start of the set power generation time period, the heat recovery circulation means C1 is operated, the tank water supply means W1 is operated to store a target storage amount, and the hot water supply circulation means C2 is moved to the hot water storage tank. The normal hot water tank hot water circulation operation that is operated in the hot water circulation state is executed.
In other words, the exhaust heat recovery circulation pump P3 is operated in a state where the tank hot water circulation switching three-way valve V2 is switched to the normal circulation state and the hot water tank side tank heating switching three-way valve V6 is switched to the exhaust heat recovery state. In this state, the exhaust heat recovery circulation means C1 is operated, and the upstream circulation is performed in a state where the three-way valve V3 is switched to the shutoff state and the three-way valve V3 is switched to the stop state. By operating the pump P4 and the downstream circulation pump P5, the hot water supply circulation means C2 is operated in the hot water tank hot water circulation state, and based on the detection information of the water level sensor L, the storage amount of the hot water tank 3 is reduced. By operating the tank water supply pump P2 so as to reach the target storage amount, the tank water supply means W1 is operated to store the target storage amount in the hot water storage tank 3.
[0057]
As shown in FIG. 1, in the normal hot water tank hot water circulation operation, the engine cooling water circulates through the exhaust heat recovery heat exchanger 2 and the auxiliary heating heat exchanger 6, and the hot water in the hot water tank 3 is discharged. The heat recovery circulation path 10 circulates through the exhaust heat recovery heat exchanger 2 and the hot water supply circulation path R circulates around a plurality of dwelling units H, and the storage amount of the hot water storage tank 3 reaches the target storage amount. Water is supplied to the hot water storage tank 3 through the tank water supply passage 9 so as to maintain the amount.
That is, the hot and cold water taken out from the small storage section 3s of the hot water storage tank 3 is heated by the heat exchange action with the engine cooling water in the exhaust heat recovery heat exchanger 2 and returned to the main storage section 3m. 3 is heated, and the hot water in the hot water storage tank 3 passes through the plurality of dwelling units H and is heated by the auxiliary heat exchanger 6 by the heat exchange action with the engine cooling water. Circulate through the circulation path R for use.
[0058]
In addition, during the normal hot water tank circulation operation, the auxiliary heating control is executed as follows. That is, when the temperature detected by the hot water tank removal temperature sensor T3 is equal to or higher than the target heating temperature, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating stop state. When the temperature detected by the hot water tank removal temperature sensor T3 is lower than the target heating temperature, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating state, and the water heater side tank temperature switching three-way valve V7 is switched to the auxiliary heating state. Switch to. Then, hot water flows through the first heat exchanger of the auxiliary water heater B, and the detection flow rate of the first water supply amount sensor Q1 becomes equal to or greater than the set amount. Based on that, the gas burner 73 is ignited as described above, and Then, the combustion amount control is performed such that the hot water temperature from the first heat exchanger 71 becomes the heating target temperature. That is, in the combustion amount control, the temperature of the hot water flowing out of the first heat exchanger 71 is set based on the target heating temperature, the temperature detected by the hot water tank removal temperature sensor T3, and the detected water supply amount by the first water supply amount sensor Q1. The feedforward control that adjusts the opening of the gas proportional valve 76 so as to reach the temperature is executed, and the opening of the gas proportional valve 76 is performed based on the deviation between the detected temperature of the first tapping temperature sensor T1 and the heating target temperature. The feedback control for finely adjusting the degree is executed.
[0059]
In each dwelling unit H, hot water is supplied by the water heater K using hot water flowing through the hot water circulation path R as described below.
That is, in the summer and the intermediate period, since the heating target temperature is set to the summer intermediate period target heating temperature higher than the normal hot water supply target temperature setting range, regardless of whether auxiliary heating is performed by the auxiliary water heater B or not, Since hot water having a temperature higher than the normal hot water supply target temperature setting range flows through the location of the circulation route R via the dwelling unit, in each dwelling unit H, when the hot water supply target temperature is set to the normal hot water supply target temperature setting range, In addition, the water heater K is operated in a mode in which the mixing section Km is operated to be mixed in a state where the heating section Kh is not operated to be heated, so that the heating operation is not performed after the water mixing, thereby saving energy.
In winter, the heating target temperature is set to the winter target heating temperature lower than the normal hot water supply target temperature setting range and equal to the low set mixing temperature. In winter, usually, it is often not possible to heat the hot water in the hot water storage tank 3 to a temperature higher than the winter target heating temperature only by heating with the exhaust heat of the generator 1. Since hot water with a low set mixing temperature frequently flows, in each dwelling unit H, when the hot water supply target temperature is set in the normal hot water supply target temperature setting range, the water heater K is not operated to mix the mixing section Km. In this state, the heating unit Kh can be mainly operated in a heating operation, and the heating operation after mixing the water is prevented from occurring as much as possible, thereby saving energy.
[0060]
When the set power generation time period ends and the non-power generation time period starts, the exhaust heat recovery circulation means C1 and the tank water supply means W1 are stopped, and the hot water supply circulation means C2 is brought into the hot water tank hot water circulation state. Water supply stop hot water storage tank operated by hot water circulation operation.
[0061]
That is, by stopping the exhaust heat recovery circulation pump P3 from the control state of the normal hot water tank hot water circulation operation described above, the exhaust heat recovery circulation means C1 is stopped, and the tank water supply pump P2 is stopped. By this, the tank water supply means W1 is stopped, but the hot water circulation means C2 is continuously operated in the hot water circulation state.
[0062]
As shown in FIG. 2, in the water supply stoppage hot water tank hot water circulation operation, the circulation of the engine cooling water stops, the circulation of hot water in the hot water tank 3 through the exhaust heat recovery circulation path 10 stops, and the generator In the state where the heating of the hot water in the hot water storage tank 3 by the exhaust heat of 1 is stopped, and the replenishment of the water from the water receiving tank 5 to the hot water storage tank 3 is stopped, the hot water in the hot water storage tank 3 is transferred to the hot water supply circulation path R. Circulates around a plurality of dwelling units H.
[0063]
The above-described auxiliary heating control is also performed during the water supply stop hot water tank hot water circulation operation.
During the water replenishment stop hot water tank hot water circulation operation, the state of the temperature of the hot water flowing through the location of the hot water supply circulation route R via the dwelling unit is the same as that during the normal hot water storage tank hot water circulation operation described above. In the same manner as during the normal hot water tank hot water circulation operation described above, hot water is supplied by the hot water heater K using hot water flowing through the hot water circulation path R, and a description thereof will be omitted.
[0064]
During the non-power generation time zone, the water level sensor L is set at a time that is equal to or longer than the required water quality maintenance time obtained by adding the set water quality maintenance operation time and the set water replacement time to the start time of the next set power generation time zone. When the detected water level reaches the set lower limit water level, the storage amount of the main storage unit 3m becomes zero, and the entire amount is stored in the small storage unit 3s, that is, when the storage amount of the hot water storage tank 3 becomes the set lower limit storage amount. While maintaining the stopped state of the exhaust heat recovery circulation means C1 and the tank water supply means W1, the hot water supply circulation means C2 is operated in the water supply state to execute the water supply state operation.
[0065]
In other words, by stopping the upstream-side circulation pump P4 and the downstream-side circulation pump P5 and switching the water supply switching three-way valve V4 to the water supply path connection state from the control state of the water supply stop hot water tank hot water circulation operation described above, The hot water supply circulation means C2 is operated in a water supply state.
[0066]
As shown in FIG. 3, in the water supply state operation, the circulation of the hot water in the hot water storage tank 3 through the exhaust heat recovery circulation path 10 and the hot water supply circulation path R is stopped, and the hot water is transferred from the water receiving tank 5 to the hot water storage tank 3. In the state in which the supply of water is stopped, the water in the water receiving tank 5 is supplied to the hot water supply circulation path R through the water supply switching three-way valve V4.
[0067]
The above-described auxiliary heating control is also performed during the water supply state operation.
During the water supply state operation, the state of the temperature of the hot water flowing through the location of the hot water circulation path R via the dwelling unit is the same as in the above-described normal hot water tank hot water circulation operation. As in the case of the hot water circulation operation, hot water is supplied by the water heater K using hot water flowing through the hot water circulation path R, and a description thereof will be omitted.
[0068]
During the non-power generation time zone, the time before the water quality maintenance required time before the start time of the next set power generation time zone, regardless of whether the water supply state operation is being performed or not, that is, the non-power generation time At the end of the setting of the zone, the hot water storage tank is maintained in a state where the circulating means for exhaust heat recovery C1 and the water supply means W1 for the tank are stopped and the circulation means C2 for hot water supply is maintained in the water supply state. A water tank maintenance operation for heating the water heater B for auxiliary heating is performed during the set water quality maintenance operation time so as to heat the hot water of No. 3 to a water quality maintenance temperature at which the quality of the hot water can be maintained. I do.
[0069]
That is, when the water supply state operation is being performed, the auxiliary heating switching three-way valve V5 is switched from the control state of the water supply state operation to the auxiliary heating stop state, and the tank water / water circulation switching three-way valve V2 is set to the tank heating state. The three-way valve V6 and the three-way valve V7 for switching between the hot water tank and the water heater are switched to the above-mentioned tank-heating state, and the circulation pump P3 for exhaust heat recovery and the pump P7 for the tank heating are switched. When the water supply operation is not performed, the upstream circulation pump P4 and the downstream circulation pump P5 are stopped from the control state of the above-described water supply stoppage hot water circulation operation, and the water supply switching three-way valve is operated. V4 is switched to the water supply path connection state, the auxiliary heating switching three-way valve V5 is switched to the auxiliary heating stop state, the tank hot water circulation switching three-way valve V2 is switched to the tank heating state, and the hot water tank side tank heating switching is performed. Switched-way valve V6 and the water heater side SoNoboru temperature switching three-way valve V7 respectively the SoNoboru-temperature state, as well, to actuate the exhaust heat recovery circulating pump P3 and SoNoboru temperature pump P7.
[0070]
As shown in FIG. 4, in the hot water tank water quality maintenance operation, the supply of water from the water receiving tank 5 to the hot water tank 3 is stopped, and the outflow of hot water in the hot water supply circulation path R to the hot water tank 3 is prevented. In this state, the water in the water receiving tank 5 is supplied to the hot water supply circulation path R through the water supply switching three-way valve V4, and flows through the hot water supply circulation path R without passing through the auxiliary water heater B. After the hot and cold water in the small storage unit 3s flows through both the first heat exchanger 71 and the second heat exchanger 72 of the auxiliary water heater B and is heated, the hot water is returned to the small storage unit 3s through the branch channel 10b. So that it is circulated. In each dwelling unit H, hot water is supplied by the water heater K using water in the water receiving tank 5 flowing through the hot water supply circulation path R.
In addition, during execution of the hot water tank water quality maintenance operation, the water flows out of the first heat exchanger 71 based on the water quality maintenance temperature, the temperature detected by the small storage portion removal temperature sensor T5, and the detected water supply amount by the first water supply amount sensor Q1. The feedforward control for adjusting the opening of the gas proportional valve 76 is executed so that the temperature of the hot water becomes the water quality maintaining temperature, and based on the deviation between the temperature detected by the first hot water temperature sensor T1 and the water quality maintaining temperature. The feedback control for finely adjusting the opening of the gas proportional valve 76 is executed.
Since the hot water in the small storage section 3s is heated to the water quality maintaining temperature by the hot water tank water quality maintenance operation, and the hot water in the small storage section 3s is heated by both the first heat exchanger 71 and the second heat exchanger 72. In addition, the operation time of the hot water storage tank water quality maintenance operation can be reduced.
[0071]
When the hot water tank water quality maintenance operation is completed, a water replacement operation is performed in which the hot water supply circulation means C2 is operated in the water replacement state.
That is, from the control state of the hot water tank water quality maintenance operation, the exhaust heat recovery circulation pump P3 and the tank temperature raising pump P7 are stopped, the heating of the hot water in the small storage 3s by the auxiliary water heater B is stopped, and the tank return is stopped. The three-way valve V3 is switched to the tank return state, and the state is maintained during the set water replacement time.
[0072]
As shown in FIG. 5, in the water replacement operation, the water in the water receiving tank 5 is supplied to the hot water circulation path R through the water supply switching three-way valve V4, and flows through the hot water circulation path R without passing through the auxiliary water heater B. Then, the hot water in the hot water supply circulation path R is replaced by the tap water in the water receiving tank 5 over substantially the entire length of the hot water supply circulation path R, and is discharged into the main storage section 3m. Water quality will be maintained. Moreover, since the tap water in the hot water supply circulation path R is replaced with the tap water in the water receiving tank 5, the quality of the hot water in the hot water supply circulation path R is further improved by the sterilizing action of chlorine contained in the tap water.
Then, as the water replacement operation ends and the next set power generation time period starts, the normal hot water circulation operation is performed.
[0073]
Also, during the non-power generation time period, the operation control unit U performs the non-power generation time period heat load as described above based on the detection information of each dwelling unit-based hot water supply sensor Q3 and the dwelling unit supply temperature sensor T4. And the stored information of the non-power generation time period heat load stored in the storage means is rewritten to the newly obtained non-power generation time period heat load heat. The operation control unit U determines the target storage amount of the operation target cycle based on the rewritten non-power generation time period heat load and the heating target temperature.
[0074]
Although not shown, the operation panel for instructing the operation control unit U to issue various operation commands is provided with a maintenance operation instruction unit for artificially instructing execution of the maintenance operation.
When a maintenance operation is instructed, the operation control unit U stops the exhaust heat recovery circulation means C1 and the tank water supply means W1, and operates the hot water supply circulation means C2 in the water supply state. Execute
The control operation of the maintenance operation is the same as the above-described water supply state operation, and the flow state of the water from the water receiving tank 5 is the same as the above-described water supply state operation, and thus the description thereof is omitted.
The maintenance operation is performed when the generator 3 fails to supply exhaust heat from the generator 3 or when maintenance is performed, or when the hot water tank 3 that cannot store hot water in the hot water tank 3 is maintained. It is also possible to supply hot water to each dwelling unit H through the hot water supply circulation path R at the time of maintenance or at the time of maintenance of the hot water storage tank 3.
[0075]
Next, an operation pattern of the cogeneration system configured as described above over time will be described.
FIG. 7 shows an example of an operation pattern in winter, and FIG. 8 shows an example of an operation pattern in summer. During the set power generation time period from 14:00 to 23:00 in winter and from 18:00 to 24:00 in summer, the generator 1 is operated and the normal hot water circulation is performed. 7 and 8, the operating state of the generator 1 is indicated by the fact that exhaust heat is generated from the generator 1. During the execution of the normal hot water tank hot water circulation operation, the storage amount of the hot water tank 3 is maintained at the target storage amount, the temperature of the hot water in the hot water tank 3 changes, and the temperature of the hot water flowing through the hot water supply circulation path R becomes the target heating temperature. When the temperature is lower than the temperature, the auxiliary water heater B is heated to the target heating temperature.
With the end of the set power generation time period, the generator 1 is stopped and the water supply stoppage hot water tank hot water circulation operation is executed. During the execution of the water supply stop hot water tank hot water circulation operation, as shown in FIG. As described above, when the storage amount of the hot water storage tank 3 becomes equal to or less than the set lower limit storage amount at the time before the water quality maintenance required time or more before the start time of the next set power generation time zone, the water supply state operation is executed. During the execution of the water supply stoppage hot water tank hot water circulation operation and the water supply state operation, when the temperature of the hot water flowing through the hot water supply circulation path R becomes lower than the target heating temperature, the auxiliary heating water heater B is set to the target heating temperature. Heated. In FIG. 8, the storage amount of the hot water storage tank 3 is maintained to be larger than the set lower limit storage amount until the water quality maintenance required time is earlier than the start time of the next set power generation time zone, and the water supply state operation is not executed. Showing driving patterns,
Subsequently, when the time before the water quality maintenance required time comes before the start time of the next set power generation time zone, the hot water tank water quality maintenance operation is executed. By the hot water tank water quality maintaining operation, the hot water in the hot water tank 3 is heated to the water quality maintaining temperature.
Subsequently, when the hot water storage tank water quality maintenance operation ends, the water replacement operation is executed. By this water replacement operation, the hot and cold water in the hot water supply circulation path R is replaced with the water in the water receiving tank 5 over substantially the entire length thereof.
[0076]
Hereinafter, each of the second and third embodiments of the present invention will be described. However, the same reference numerals are given to the same components and components having the same operations as those of the first embodiment in order to avoid redundant description. The description will be omitted, and a configuration different from the first embodiment will be mainly described.
[0077]
[Second embodiment]
Hereinafter, a second embodiment will be described.
As shown in FIG. 9, in the second embodiment, the configuration of the cogeneration system is the same as that of the above-described first embodiment, and the control operation of the operation control unit U is different from the water replacement operation in the first embodiment. Instead, the circulation path water quality maintenance operation for heating the auxiliary water heater B is performed so that the hot water in the hot water supply circulation path R is heated to a water quality maintenance temperature at which the quality of the hot water can be maintained. The second embodiment is the same as the first embodiment except for the difference.
[0078]
That is, in the circulation path water quality maintaining operation, the hot water circulating through the hot water supply circulation path R is heated to the water quality maintaining temperature by the auxiliary water heater B in the state following the hot water tank water quality maintaining operation, It is operated in the hot water tank hot water circulation state.
That is, from the control state of the hot water tank water quality maintenance operation, the exhaust heat recovery circulation pump P3 and the tank temperature raising pump P7 are stopped, the heating of the hot water of the small storage 3s by the auxiliary water heater B is stopped, and the water supply switching three-way is performed. The valve V4 is switched to the water supply path shut-off state, the auxiliary heating switching three-way valve V5 and the water heater side tank heating switching three-way valve V7 are each switched to the auxiliary heating state, and the tank return stop three-way valve V3 is switched to the tank return state. This state is continued for the set water replacement time.
Further, the temperature of the hot water flowing out of the first heat exchanger 71 is adjusted to the water quality maintaining temperature based on the water quality maintaining temperature, the detected temperature of the hot water tank removal temperature sensor T3, and the detected water supply amount of the first water supply amount sensor Q1. And feed-forward control for adjusting the opening of the gas proportional valve 76, and finely adjusting the opening of the gas proportional valve 76 based on the deviation between the temperature detected by the first hot water temperature sensor T1 and the water quality maintaining temperature. Execute feedback control.
[0079]
As shown in FIG. 9, in the circulation path water quality maintenance operation, in a state where the supply of water from the water receiving tank 5 to the hot water storage tank 3 is stopped, the hot and cold water taken out from the small storage unit 3 s is supplied to the auxiliary water heater B. In the state where the hot water is maintained at the water quality maintaining temperature, the hot water flows through the hot water supply circulation path R and is returned to the main storage section 3m, so that the hot water having the water quality maintenance temperature flows over substantially the entire length of the hot water supply circulation path R. Will be.
The circulation path water quality maintenance operation is performed after the hot water tank water quality maintenance operation, so that the hot water having the approximate water quality maintenance temperature after the hot water tank water quality maintenance operation is subjected to the water quality maintenance temperature by the auxiliary water heater B. In this case, the energy consumption is reduced.
Since the operation time of the hot water tank water quality maintenance operation is short, even if the hot water flowing through the hot water supply circulation path R is used in each dwelling unit H, the small storage unit is in such a degree as to hinder the circulation of the hot water. The storage amount of 3s does not decrease.
[0080]
[Third embodiment]
Hereinafter, a third embodiment will be described.
As shown in FIG. 10, in the third embodiment, the configuration of the cogeneration system is the same as that of the first embodiment except that the configurations of the hot water tank 3 and the exhaust heat recovery circulating means C1 are different.
That is, similarly to the first embodiment, the hot water storage tank 3 includes the main storage section 3m and the small storage section 3s having a smaller cross-sectional area than the main storage section 3m. The specific configuration of the small storage section 3s is different from that of the first embodiment.
The hot water storage tank 3 is formed in an open shape by a substantially rectangular parallelepiped box-shaped tank forming member having an open upper part, a part of the bottom of the tank forming member is depressed to form a recess, and a small recess is formed by the recess. The storage portion 3s is formed, and a portion other than the concave portion in the tank forming member is set as the main storage portion 3m.
The water level sensor L is provided so as to measure the water level from the main storage section 3m to the small storage section 3s, and the circulation path 4 through the tank takes out hot water from the bottom of the small storage section 3s and corresponds to above the small storage section 3s. It is provided so as to return to the upper part of the main storage part 3m.
[0081]
The exhaust heat recovery circulating means C1 omits the branch path 10b and the tank hot water circulation switching three-way valve V2 provided in the first embodiment, and recovers the hot water taken out from the bottom of the small storage section 3s of the hot water storage tank 3 by heat exhaust heat. Heat recovery circulation path 10, which is arranged to flow back from the upper part of the main storage section 3 m via the heat exchanger 2, and a heat recovery circulation pump P 3 provided in the heat recovery circulation path 10. And is configured.
[0082]
Next, a control operation of the operation control unit U will be described.
The power supply control is the same as in the first embodiment, and a description thereof will be omitted.
In the hot water supply control, the normal hot water tank hot water circulation operation, the water supply stop hot water tank hot water circulation operation, the water supply state operation, the hot water tank water quality maintenance operation, and the water replacement operation are automatically executed as in the first embodiment. The maintenance operation is executed based on a command from the maintenance operation command section of the operation panel. The control operation in each operation is the same as that of the first embodiment except that there is no control operation of the tank hot water circulation switching three-way valve V2, and thus the description is omitted.
Further, the flow forms of the engine cooling water, the hot water in the hot water storage tank 3 and the water in the water receiving tank 5 in each operation are the same as those in the first embodiment except that the flow forms in the hot water storage tank water quality maintenance operation are different. Differences in the flow form of the tank water quality maintenance operation from the first embodiment will be described, and description of the flow form of other operations will be omitted.
That is, in the first embodiment, after the hot water in the small storage section 3s of the hot water tank 3 is heated by the auxiliary water heater B, the hot water is directly returned to the small storage section 3s through the branch path 10b of the exhaust heat recovery circulation path 10. On the other hand, in the third embodiment, after the hot water in the small storage unit 3s of the hot water tank 3 is heated by the auxiliary water heater B, the small storage from the upper part of the main storage unit 3m through the exhaust heat recovery circulation path 10. The flow form of the hot water tank water quality maintenance operation in the third embodiment is different from that of the first embodiment in that it is returned to the section 3s.
[0083]
[Another embodiment]
Next, another embodiment will be described.
In the above-described embodiment, a case where the generator 1 is operated in a mode in which the generator 1 is operated during a part of the set power generation time of a day and stopped in a non-power generation time other than the set power generation time is exemplified. However, the generator 1 may be operated continuously without being stopped. In this case, the operation is only the normal hot water tank hot water circulation operation.
[0084]
In the above embodiment, the storage amount that can be consumed or substantially consumed in the non-power generation time period is set as the target storage amount of the hot water storage tank 3, and the target storage amount is stored in the hot water storage tank 3 in the set power generation time period. The case where the tank water supply means W1 is operated to store hot water and the tank water supply means W1 is operated in the non-power generation time period while the tank water supply means W1 is stopped is exemplified. Alternatively, the tank water supply means W1 may be operated in such a manner that the tank water supply means W1 is operated so as to store a preset amount of hot water in the hot water storage tank 3. Also in this case, the operation is only the normal hot water circulation operation.
[0085]
The heating target temperature is not limited to the temperature exemplified in the above embodiment, and can be set to various temperatures. For example, only one temperature higher than the normal hot water supply target temperature setting range may be set. Alternatively, the temperature may be set within the normal hot water supply target temperature setting range. However, for energy saving, it is preferable to set the temperature outside the normal hot water supply target temperature setting range.
When the heating target temperature is set to a temperature lower than the normal hot water supply target temperature setting range, the water heater K is prevented from being operated as much as possible in the heating operation after mixing the water, and in order to save energy, the low temperature is set. Set the temperature below the set mixing temperature.
[0086]
In the above embodiment, the heat load detecting means is configured to determine the total heat amount of hot water supplied to the plurality of dwelling units H through the hot water supply circulation means C2 during the non-power generation time period as the non-power generation time period heat load. Although the case of performing is exemplified, the total flow rate of the hot water supplied to the plurality of dwelling units H through the hot water supply circulation means C2 during the non-power generation time zone may be obtained as the non-power generation time heat load. In this case, the total flow rate of hot and cold water in the cycle before the operation target cycle obtained as the non-power generation time zone heat load is set as the target storage amount of the operation target cycle.
In setting the target storage amount of the cycle to be operated based on the heat load during the non-power generation time period detected by the heat load detection means, a specific setting method can be changed. For example, the non-power generation time period heat load detected every day is averaged every month, the average value is stored in the storage unit in association with the month, and based on the stored information, the target storage amount of the operation target cycle. May be set.
[0087]
In the above embodiment, the case where the target storage amount of the operation target cycle is changed and set based on the heat load during the non-power generation time period detected by the heat load detection means has been exemplified, but a cogeneration system is installed. In consideration of the heat load of the target area or apartment complex, the target storage amount is stored in the storage unit in advance in association with the month or in advance in association with the month and the day of the week, based on the storage information. In addition, the target storage amount of the operation target cycle may be fixedly set every month or every day of the week.
[0088]
In the above embodiment, the hot water supply circulation path R forms a hot water tank bypass path that passes through a plurality of dwelling units H in a state of bypassing the hot water storage tank 3 using the via-tank circulation path 4 and the tank bypass path 12. However, instead of this, the hot water supply circulation path R uses a plurality of dwelling units H included in the apartment house using hot water taken out from the small storage section 3s of the hot water storage tank 3 using only the circulation path 4 via the tank. It may be configured to form a path for returning to the upper part of the main hot water storage section 3m via.
[0089]
In the above-described embodiment, the case where the hot water storage tank 3 is configured to include the main storage part 3m and the small storage part 3s having a smaller cross-sectional area than the main storage part 3m is illustrated, but only one storage part is used. You may comprise so that it may be provided.
[0090]
In the above-described embodiment, the case where the auxiliary water heater B serving both as the auxiliary heating means B1 for the hot water storage tank and the auxiliary heating means B2 for the circulation path is provided is exemplified, but the auxiliary heating means B1 for the hot water tank and the auxiliary heating for the circulation path are provided. The means B2 may be provided separately.
In this case, during the hot water tank water quality maintenance operation, the water supply state operation is performed in parallel while the hot water flowing through the hot water supply circulation path R is heated to the target heating temperature by the circulation path auxiliary heating means B2. Therefore, hot water at the target heating temperature can be supplied to each dwelling unit H even during the execution of the hot water storage tank water quality maintenance operation.
[0091]
The configuration of the water heater K provided in each dwelling unit H can be changed. For example, when the circulating hot water temperature is lower than the hot water supply target temperature, the mixing operation of the mixing section Km is controlled so that the set mixing temperature is set to be lower than the hot water supply target temperature by the set temperature difference or more, In addition, the heating operation of the heating unit Kh is controlled so that the hot water supply temperature becomes the hot water supply target temperature. When the circulating hot water temperature is equal to or higher than the hot water supply target temperature, the heating operation of the heating unit Kh is stopped. The mixing operation of the mixing section Km may be controlled so that the temperature becomes the hot water supply target temperature.
[0092]
In the above embodiment, the case where the water receiving tank 5 is used as the water supply source has been illustrated, but the water supply itself may be used as the water supply source. In this case, a water pipe is connected to each of the tank water supply path 9 and the circulation water supply path 14.
[0093]
In the case where the power generation means is constituted by an engine driven rotary generator 1 driven by an engine such as a gas engine as in the above embodiment, the generator supplied to the exhaust heat recovery heat exchanger 2 As the exhaust heat of 1, the exhaust gas of the engine may be supplied in addition to the engine cooling water exemplified in the above embodiment, or both the engine cooling water and the exhaust gas may be supplied. When the power generation means is constituted by the engine-driven rotary generator 1, the engine may be various types such as LP gas, petroleum, gasoline, etc., in addition to the one using the city gas exemplified in the above embodiment as a fuel. Can be used.
Further, the power generating means may be constituted by a gas turbine driven rotary generator driven by a gas turbine, in addition to the engine driven rotary generator 1 as exemplified in the above embodiment. good. When the power generation means is constituted by a gas turbine driven rotary generator, the exhaust heat recovery heat exchanger 2 is configured to supply the exhaust gas of the gas turbine as exhaust heat.
Further, the power generation means is not limited to the rotary generator as described above, but may be constituted by, for example, various fuel cells. When the power generation means is configured by a fuel cell, the exhaust heat recovery heat exchanger 2 is configured to supply cooling water of the fuel cell as waste heat.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a cogeneration system according to a first embodiment, and a configuration of hot water flow in a normal hot water tank hot water circulation operation.
FIG. 2 is a view showing a water flow pattern in a water supply stoppage hot water tank hot water circulation operation of the cogeneration system according to the first embodiment;
FIG. 3 is a diagram showing the flow of hot and cold water in a water supply state operation and a maintenance operation of the cogeneration system according to the first embodiment.
FIG. 4 is a diagram showing the flow of hot and cold water in a hot water storage tank water quality maintaining operation of the cogeneration system according to the first embodiment.
FIG. 5 is a diagram showing a hot water flow pattern in the water replacement operation of the cogeneration system according to the first embodiment.
FIG. 6 is a diagram showing a configuration of a water heater of the cogeneration system according to the embodiment.
FIG. 7 is a diagram showing an operation pattern of the cogeneration system according to the first embodiment.
FIG. 8 is a diagram showing an operation pattern of the cogeneration system according to the first embodiment.
FIG. 9 is a diagram showing the configuration of a cogeneration system according to a second embodiment and the flow of hot and cold water in a circulation path water quality maintenance operation.
FIG. 10 is a diagram showing a configuration of a cogeneration system according to a third embodiment.
FIG. 11 is a diagram showing a configuration of a conventional cogeneration system.
[Explanation of symbols]
1 Power generation means
2 Exhaust heat recovery heat exchanger
3 Hot water storage tank
5 water supply sources
B2 Auxiliary heating means
C1 Waste heat recovery circulation means
C2 Circulating means for hot water supply
H dwelling unit
K water heater
Kh heating unit
Km mixing section
R Circulation route for hot water supply
U operation control means
Water supply means for W1 tank
Water supply means for W2 circulation
W3 Water supply means for dwelling units

Claims

A power generating means for generating electric power for an area or an apartment house, an exhaust heat recovery heat exchanger supplied with exhaust heat from the electric power generating means, and a plurality of dwelling units included in the area or the apartment house for hot water supply. A hot water storage tank for storing, a water supply means for a tank for supplying water to the hot water storage tank, an exhaust heat recovery circulating means for circulating hot water between the exhaust heat recovery heat exchanger and the hot water storage tank, and the hot water storage tank and the plurality of hot water storage tanks. A cogeneration system provided with hot water circulation means for circulating hot water in a hot water circulation path extending to the dwelling unit,
A cogeneration system provided with auxiliary heating means for heating hot water flowing through the hot water supply circulation path.

Operation control means for controlling the operation, in a set power generation time zone set as a partial time zone of the day, to operate the power generation means, the exhaust heat recovery circulation means and the hot water circulation means, In a non-power generation time zone other than the set power generation time zone, the power generation means and the exhaust heat recovery circulation means are stopped and the hot water supply circulation means is operated, and
In the set power generation time zone and the non-power generation time zone, the configuration is such that the operation is controlled in a form in which the auxiliary heating means is operated to heat the hot water flowing through the hot water supply circulation path to a target heating temperature. The cogeneration system according to claim 1, wherein:

A dwelling unit water supply means for supplying water to each of the plurality of dwelling units is provided,
A mixing unit that mixes hot water supplied through the hot water supply circulating unit with water supplied through the hot water supply unit, and heating the hot water supplied from the mixing unit to each of the plurality of dwelling units; A hot water supply unit for supplying hot water to the hot and cold water demanding unit is provided,
When the temperature of the hot water is lower than the target hot water temperature by a set temperature difference or more, the mixing is performed so that the set mixing temperature is set to be lower than the target hot water temperature by the set temperature difference or more. Controlling the mixing operation of the hot water supply unit and controlling the heating operation of the heating unit so that the hot water supply temperature becomes the hot water supply target temperature, wherein the temperature of the hot water is lower than the temperature lower than the set temperature difference with respect to the hot water supply target temperature. Is also high, in a state where the heating operation of the heating unit is stopped, configured to control the mixing operation of the mixing unit so that the hot water supply temperature becomes the hot water supply target temperature,
The cogeneration system according to claim 2, wherein the target heating temperature is set to a temperature outside a set range of the hot water supply target temperature in the water heater.

The target heating temperature is set to a temperature lower than the set range, a winter target heating temperature used in winter, and a summer intermediate temperature set to a temperature higher than the set range and used at a time other than winter. 4. The cogeneration system according to claim 3, further comprising a target heating temperature.

Circulation water supply means for supplying water from the water supply source to the hot water circulation path is provided,
The hot-water supply circulating means circulates the hot-water in the hot-water storage tank in the hot-water supply circulating path, and stops the hot-water supply in the hot-water storage tank and circulates the hot-water in the circulation hot water supply means. It is configured to be freely switchable to a water supply state that supplies water to the circulation path,
As the target storage amount of the hot water tank, a storage amount that can be consumed or substantially consumed in the non-power generation time zone is set,
In the state in which the operation control means activates the tank water supply means to store the target storage amount of hot water in the hot water tank during the set power generation time period, the hot water supply circulation means causes the hot water tank water circulation. When the storage amount of the hot water storage tank is larger than a set lower limit storage amount in a state where the water supply means for the tank is stopped in the non-power generation time zone, the circulation means for hot water supply is changed to the hot water storage tank. The hot water circulation means is operated in the hot water circulation state, and when the storage amount of the hot water tank is equal to or less than the set lower limit storage amount, the hot water supply circulation means is operated in the water supply state. The cogeneration system according to any one of the above.