JP6449590B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus, and more particularly to a hot water supply apparatus that does not require a drain pipe.

  Patent Document 1 discloses a conventional hot water supply apparatus. The hot-water supply device described in Patent Document 1 (in Japanese Patent Application Laid-Open No. 2004-260688) includes a main heat exchanger that recovers sensible heat of combustion exhaust gas and a sub heat exchanger that recovers latent heat of combustion exhaust gas. The auxiliary heat exchanger is connected to the downstream side of the water supply pipe. The main heat exchanger is connected to the downstream side of the sub heat exchanger. A tapping pipe is connected to the downstream side of the main heat exchanger.

  The water supplied to the water supply pipe rises in temperature by exchanging heat with the combustion exhaust in the auxiliary heat exchanger, and further rises in temperature by exchanging heat with the combustion exhaust in the main heat exchanger. Water heated to a high temperature by the main heat exchanger is discharged through a discharge pipe.

  At this time, since the sensible heat is recovered by the main heat exchanger and the latent heat is recovered by the auxiliary heat exchanger, the combustion exhaust is condensed and changed into a drain.

  The water heater described in Patent Document 1 is provided with a drain evaporator below the auxiliary heat exchanger. The drain evaporator is configured to receive the drain generated by the auxiliary heat exchanger and be heated by the combustion exhaust. Thereby, the water heater described in Patent Document 1 has a structure that does not require a drain pipe for discharging the drain generated in the auxiliary heat exchanger to the outside of the apparatus.

JP 2002-98413 A

  By the way, the water heater described in Patent Document 1 realizes a structure in which drain is evaporated by heating the drain evaporator, thereby eliminating drain piping. However, depending on the user, the water heater may be used continuously for a long time. In this case, the amount of drain generated from the auxiliary heat exchanger may exceed the amount of drain evaporation by the drain evaporator. is there. If the operation of the water heater is continued in this case, the drain overflows from the drain evaporator, and as a result, there is a problem that the water leaks from the water heater.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to recover sensible heat and latent heat of combustion exhaust gas and continuously use it for a long time in a hot water supply apparatus that does not require a drain pipe. Even if it is a case, it is providing the hot-water supply apparatus which can suppress the leak of drain.

The invention according to claim 1 of the present invention includes a supply pipe provided with a water supply port at an upstream end, a first heat exchanger connected to the supply pipe, and the first heat exchanger. A second heat exchanger connected to the downstream side of the first heat exchanger, a tapping pipe connected to the downstream side of the second heat exchanger and provided with a tapping outlet at the downstream end thereof, and the first heat exchanger A heat exchanger and a burner that exchanges heat with combustion exhaust, and recovers sensible heat of the combustion exhaust with the second heat exchanger, and with the first heat exchanger. A hot water supply apparatus configured to recover latent heat of combustion exhaust after heat exchange with the second heat exchanger, wherein the first heat exchanger includes a surface of the first heat exchanger. the dew condensation water holding section for holding the condensed water on the surface caused is provided, the condensed water holding section, configured by a porous material It is characterized in that.

When the invention according to claim 1 is used continuously for a long time, condensed water is generated on the surface of the first heat exchanger, and this condensed water is held in the condensed water holding portion. When the condensed water is held in the condensed water holding unit, the surface of the first heat exchanger is covered with the condensed water. Thereby, the part covered with the dew condensation water of the 1st heat exchanger becomes difficult to be heat-exchanged with combustion exhaust, As a result, it can suppress that dew condensation water newly arises. Therefore, according to the hot water supply apparatus of the present invention, it is possible to suppress drain leakage even when the apparatus is continuously used for a long time.
Further, even when the condensed water is held in the condensed water holding part and the heat exchange with the combustion exhaust of the first heat exchanger is suppressed, the condensed water holding part is applied to the combustion exhaust, Water can be evaporated. Thereby, the 1st heat exchanger can be quickly returned to the state which can collect | recover heat | fever effectively.

  The invention according to claim 2 is the invention according to claim 1, wherein the first heat exchanger includes a pipe portion that communicates with the supply pipe and allows water to pass through the inside. The part is provided on the outer peripheral part of the pipe part.

  Thus, in the invention according to claim 2, the dew condensation water holding part is provided on the outer peripheral part of the pipe part. Therefore, the dew condensation water in the case of continuous use for a long time in the pipe part where a lot of dew condensation water is generated. Can be suppressed.

  According to the hot water supply device of the present invention, in a hot water supply device that recovers sensible heat and latent heat of combustion exhaust and does not require a drain pipe, it is possible to suppress drain leakage even when continuously used for a long time. it can.

It is sectional drawing of the water heater of this embodiment. It is principal part sectional drawing of the water heater of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a cross-sectional view of the hot water supply apparatus of the present embodiment. The hot water supply apparatus of the present embodiment incorporates two heat exchangers (first heat exchanger 25 and second heat exchanger 26), and not only sensible heat of combustion exhaust generated from the burner 24, It also recovers latent heat and efficiently generates hot water. On the other hand, when the latent heat is recovered, the combustion exhaust is condensed and changed into condensed water. However, when the amount of condensed water generated increases, the hot water supply device restricts the recovery of latent heat and suppresses the amount of condensed water generated. .

  The hot water supply apparatus of the present embodiment is a hot water heater that changes water into hot water and discharges the hot water to a faucet of a kitchen, a bathroom, or the like (hereinafter, the hot water supply apparatus of the present embodiment is referred to as a hot water heater). As shown in FIG. 1, the water heater includes a housing 1, a combustion chamber 2, and a control device 7.

  The housing 1 is formed in a box shape. The housing | casing 1 forms the outline of a water heater. An air supply port 11 for taking outside air into the inside is provided at the lower portion of the housing 1. Further, an exhaust port 12 for exhausting the combustion exhaust generated by the burner 24 to the outside is provided in the upper part of the housing 1.

  The combustion chamber 2 is provided in the housing 1. The combustion chamber 2 generates hot water by heating water supplied from a water supply source. In the combustion chamber 2, an inflow port 21, an outflow port 22, and a flow passage 23 are provided. The inflow port 21 is provided in the lower part of the combustion chamber 2. The inflow port 21 communicates with the air supply port 11 of the housing 1. The outlet 22 is provided in the upper part of the combustion chamber 2. The outflow port 22 communicates with the exhaust port 12 of the housing 1. The flow passage 23 communicates the inflow port 21 and the outflow port 22. The combustion chamber 2 includes a burner 24, a first heat exchanger 25, a second heat exchanger 26, and a fan 27.

  The fan 27 is provided below the inflow port 21. The fan 27 supplies outside air (secondary air for combustion) to the burner 24. When the fan 27 is driven, air is taken into the housing 1 from the air supply port 11, and the taken-in air flows into the combustion chamber 2 through the inflow port 21. The fan 27 is electrically connected to the control device 7 and is driven and controlled by the control device 7.

  The burner 24 is accommodated in the combustion chamber 2. The burner 24 is supplied with a premixed gas and burns to generate combustion exhaust. The combustion exhaust gas flows along the flow passage 23 and is discharged through the outlet port 22. The premixed gas is generated by mixing the fuel gas and the primary air before the burner 24 is combusted.

  A first heat exchanger 25 and a second heat exchanger 26 are arranged above the burner 24. The first heat exchanger 25 and the second heat exchanger 26 are provided in contact with the combustion exhaust generated from the burner 24.

  The first heat exchanger 25 is configured by thermally connecting radiating fins 35 to a meandering tube portion 34 (for example, a stainless steel tube). A supply pipe 28 is connected to the inlet of the first heat exchanger 25. A water supply port 32 is provided at the upstream end of the supply pipe 28. When water is supplied from the water supply port 32, the water flows into the first heat exchanger 25. A second heat exchanger 26 is connected to the downstream side of the first heat exchanger 25.

  The second heat exchanger 26 is provided below the first heat exchanger 25 and accommodated in the combustion chamber 2. The second heat exchanger 26 is connected to the first heat exchanger 25 through the connection pipe 30. The connection pipe 30 has an upstream end connected to the outlet of the first heat exchanger 25 and a downstream end connected to the inlet of the second heat exchanger 26.

  The second heat exchanger 26 is configured by thermally connecting radiating fins 37 to a meandering tube portion 36 (for example, a copper tube). A tapping pipe 31 is connected to the downstream end of the second heat exchanger 26. An open / close valve 29 is provided in the middle of the hot water discharge pipe 31, and the flow state of the water supplied to the water heater (that is, water discharge and water stoppage) is switched by opening / closing driving of the open / close valve 29. A hot water outlet 33 is provided at the downstream end of the hot water pipe 31.

  The hot water outlet 33 and the water supply port 32 of the supply pipe 28 are provided exposed from the lower end of the housing 1. A water supply pipe that communicates with a water supply source (for example, a water pipe) is connected to the water supply port 32. The hot water outlet 33 is connected to a hot water outlet such as a mixed water tap, for example.

  When the burner 24 burns with water supplied from the water supply port 32, the combustion exhaust generated by the burner 24 comes into contact with the second heat exchanger 26 and the combustion exhaust that has passed through the second heat exchanger 26. Comes into contact with the first heat exchanger 25. Then, the water flowing through the supply pipe 28 flows into the first heat exchanger 25, heat exchange with the combustion exhaust gas, and the temperature rises. Thereafter, the water whose temperature has risen flows into the second heat exchanger 26, exchanges heat with the combustion exhaust gas, and further rises in temperature. Then, the water that has passed through the second heat exchanger 26 is discharged from the hot water outlet 33.

  At this time, the sensible heat of the combustion exhaust is recovered by the second heat exchanger 26, and thereafter, the latent heat (latently, latent heat and sensible heat) is recovered by the first heat exchanger 25. As a result, the water heater can effectively heat the water supplied to the water supply port 32.

  When the latent heat is recovered by the first heat exchanger 25, the combustion exhaust is condensed and changed into condensed water. Accordingly, condensed water adheres to the first heat exchanger 25.

  As shown in FIG. 2, the first heat exchanger 25 is provided with a dew condensation water holding unit 5. The condensed water holding part 5 is provided so as to cover the outer peripheral part (surface) of the pipe part 34 of the first heat exchanger 25. The dew condensation water holding unit 5 holds the dew condensation water generated in the pipe part 34 of the first heat exchanger 25 and covers the surface of the pipe part 34 with the dew condensation water. Thereby, the dew condensation water holding | maintenance part 5 can suppress the heat exchange with the 1st heat exchanger 25 and combustion exhaust, and can suppress generation | occurrence | production of dew condensation water.

  The condensed water holding unit 5 is a porous body made of, for example, ceramic. Therefore, the dew condensation water holding unit 5 can evaporate the dew condensation water when exposed to the combustion exhaust gas while holding the dew condensation water. Thereby, the 1st heat exchanger 25 returns to the state which can be heat-exchanged with combustion exhaust gas again.

  A drain receiver 4 is provided below the first heat exchanger 25. This drain receiver 4 is for receiving the condensed water held by the condensed water holding part 5 dripping due to vibration or the like, for example. The drain receiver 4 is provided with a vaporizer 41. The vaporizer 41 promotes vaporization of condensed water received by the drain receiver 4. The vaporizer 41 is constituted by a porous body made of ceramic or a heater, for example.

  When the hot water heater of this embodiment is continuously used for a long time, condensed water is generated, and the condensed water is held by the condensed water holding unit 5. Then, the pipe part 34 of the 1st heat exchanger 25 is covered with condensed water.

  Then, the first heat exchanger 25 covered with the dew condensation water cannot exchange heat with the combustion exhaust gas, and therefore, the generation of the dew condensation water is suppressed. As a result, it is possible to prevent drain from leaking from the water heater.

  On the other hand, in this state, the recovery of the latent heat of the combustion exhaust by the first heat exchanger 25 is not performed, and the recovery efficiency of the heat of the combustion exhaust temporarily decreases. However, if the operation is continued in this state, the condensed water holding unit 5 is exposed to the combustion exhaust, and the condensed water evaporates. As a result, the first heat exchanger 25 is exposed from the dew condensation water, and the latent heat can be recovered again.

  As described above, the water heater (hot water supply apparatus) of the present embodiment includes the supply pipe 28, the first heat exchanger 25 connected to the supply pipe 28, and the first heat exchanger 25. A second heat exchanger 26 connected to the downstream side, a tapping pipe 31 connected to the downstream side of the second heat exchanger 26, and a burner 24 are provided. The hot water supply device recovers the sensible heat of the combustion exhaust by the second heat exchanger 26 and recovers the latent heat of the combustion exhaust after exchanging heat with the second heat exchanger 26 by the first heat exchanger 25. Configured. And the 1st heat exchanger 25 is provided with the dew condensation water holding | maintenance part 5 which hold | maintains the dew condensation water produced on the surface of the said 1st heat exchanger 25 on the surface.

  When the hot water supply apparatus of this embodiment is continuously used for a long time, condensed water is generated on the surface of the first heat exchanger 25, and this condensed water is held in the condensed water holding unit 5. When the condensed water is held in the condensed water holding unit 5, the surface of the first heat exchanger 25 is covered with the condensed water. Thereby, the part covered with the dew condensation water of the 1st heat exchanger 25 becomes difficult to carry out heat exchange with combustion exhaust, As a result, it can suppress that dew condensation water newly arises. Therefore, according to the hot water supply apparatus of the present invention, it is possible to suppress drain leakage even when the apparatus is continuously used for a long time.

  Further, the first heat exchanger 25 of the present embodiment includes a pipe portion 34 that communicates with the supply pipe 28 and allows water to flow inside. The condensed water holding part 5 is provided on the outer peripheral part of the pipe part 34.

  Thus, since the dew condensation water holding part 5 is provided in the outer peripheral part of the pipe part 34, the hot water supply device of the present embodiment is used continuously for a long time in the pipe part 34 where a lot of dew condensation water is generated. It is possible to suppress the formation of dew condensation water.

  Moreover, the dew condensation water holding | maintenance part 5 of this embodiment is comprised by the porous body.

  For this reason, even if the dew condensation water is held in the dew condensation water holding part 5 and the heat exchange with the combustion exhaust of the first heat exchanger 25 is suppressed, the dew condensation water holding part 5 is applied to the combustion exhaust, so that the dew condensation is achieved. Water can be evaporated. Thereby, the 1st heat exchanger 25 can be rapidly returned to the state which can collect | recover heat | fever effectively.

  In addition, although the hot water supply apparatus of this embodiment was what is called a hot water heater, as the "hot water supply apparatus" of the present invention, in addition to the hot water heater having the above-described hot water supply function, floor heating or bathroom heating dryer using hot water as a heat source. It may be a hot water heating heat source machine that also has a function of circulating hot water, or a bath water heater that also has a function of circulating hot water in a bathtub.

  Moreover, although the hot water heater of this embodiment switched supply of hot water and water stop by driving the on-off valve 29, the presence or absence of water in the water heater is detected without providing the on-off valve 29. A water flow sensor may be provided in the water heater, and the control device may control the combustion of the burner based on the detection signal of the water flow sensor. As a result, when the user opens and closes the hot water supply destination, the water flow sensor detects the flow of water in the water heater, and the combustion of the burner is controlled accordingly.

  Moreover, although the dew condensation water holding | maintenance part 5 of this embodiment was provided so that the pipe part 34 of the 1st heat exchanger 25 might be covered, you may cover the radiation fin 35, for example. In other words, the dew condensation water holding unit 5 suppresses heat exchange by holding the dew condensation water on the surface of both or any one of the tube part 34 and the radiation fin 35 of the first heat exchanger 25. That's fine.

  Further, the supply pipe 28 and the hot water discharge pipe 31 are connected by a bypass pipe, and a flow rate adjusting valve is provided in the bypass pipe, and the temperature of the hot water discharged from the hot water outlet 33 is adjusted by adjusting the opening degree of the flow rate adjusting valve. You may control.

DESCRIPTION OF SYMBOLS 1 Housing | casing 11 Supply port 12 Exhaust port 2 Combustion chamber 21 Inlet 22 Outlet 23 Outflow path 24 Burner 25 1st heat exchanger 26 2nd heat exchanger 27 Fan 28 Supply pipe 29 On-off valve 30 Connection pipe 31 Hot water pipe 32 Water supply port 33 Hot water outlet 34 Pipe part 35 Radiation fin 4 Drain receiver 5 Condensate water holding part 7 Control device

Claims (2)

A supply pipe provided with a water supply port at the upstream end; and
A first heat exchanger connected to the supply pipe;
A second heat exchanger connected downstream of the first heat exchanger;
A tapping pipe connected to the downstream side of the second heat exchanger, and having a tapping outlet at the downstream end thereof,
The first heat exchanger and the second heat exchanger, and a burner that performs heat exchange by combustion exhaust,
The sensible heat of the combustion exhaust is recovered by the second heat exchanger, and the latent heat of the combustion exhaust after heat exchange with the second heat exchanger is recovered by the first heat exchanger. A water heater,
The first heat exchanger is provided with a dew condensation water holding unit that holds dew condensation water generated on the surface of the first heat exchanger on the surface ,
The dew condensation water holding part is constituted by a porous body,
A water heater characterized by that. The first heat exchanger includes a pipe portion that communicates with the supply pipe and allows water to flow inside.
The hot water supply apparatus according to claim 1, wherein the dew condensation water holding portion is provided on an outer peripheral portion of the pipe portion .

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