JP5413328B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply device that stores hot water heated by a heat pump type heating device in a tank and uses the hot water at the time of discharging.

  The hot water supply device described in Patent Document 1 has a structure in which hot water boiled at a first boiling temperature is caused to flow into the tank from the top by a heat pump unit, and boiled at a second boiling temperature lower than the first boiling temperature. And a flow path switching means for switching an inflow path to these tanks. A reheating heat exchanger for heating the hot water in the bathtub is arranged in the tank, and the hot water boiled at the first boiling temperature is a peripheral part of the reheating heat exchanger in the tank. The hot water boiled at the second boiling temperature flows into a portion located below the reheating heat exchanger inside the tank.

  As a result, hot water at the second boiling temperature flows below the portion where the reheating heat exchanger is arranged, so that the amount of heat for reheating can be secured in the upper part of the tank. The heat loss is reduced and the energy efficiency is prevented from lowering compared to the case where the entire tank is filled with hot water at the first boiling temperature.

JP 2008-39339 A

  However, in the conventional heat pump type hot water supply apparatus, when the first boiling temperature is not sufficiently high, the hot water temperature in the tank decreases due to the hot water discharged from the tank or the heat exchange at the time of reheating, and the medium hot water is generated. A lot of the water stored in the tank is reheated. In addition, when the second boiling temperature is not so low, medium-temperature water is stored from the middle part to the lower part in the tank, and the medium-temperature hot water may be re-boiling. When such a boiling operation is performed, COP (efficiency) of the heat pump type hot water supply apparatus is lowered, which is not preferable in terms of energy efficiency.

  Therefore, the present invention has been made in view of the above problems, and the first boiling temperature and the first heating temperature that can secure the necessary heat amount in the tank and can reduce the temperature of the hot water stored in the lower part of the tank. It aims at providing the hot-water supply apparatus which sets 2 boiling-up temperature.

In order to achieve the above object, the following technical means are adopted. That is, the invention relating to the hot water supply apparatus according to claim 1 includes a tank (10) for storing hot water used for hot water supply, and a heat pump heating device (20) for heating the hot water extracted from the lower side of the tank. The heat exchange device (72) for exchanging heat between the water for hot water supply in the tank and a predetermined external fluid to heat the external fluid, and the water heated to the first boiling temperature by the heat pump heating device The hot water boiled to the second boiling temperature lower than the first boiling temperature by the upper inflow means (21, 22, 24) that flows into the tank from the upper part and the heat pump type heating device, and the external fluid and heat Intermediate portion inflow means (21, 22, 2) for allowing the hot water supply water to be exchanged to flow into the tank from the intermediate portion (10c1) of the tank set in a portion below the portion where the water is stored in the tank , 24, 10c), the first boiling temperature and the second boiling temperature are determined, and the operation of the heat pump heating device (20) is controlled so as to satisfy the determined temperatures, A control device (40) for controlling the operation of the part inflow means,
When the control device (40) performs the boiling operation by the heat pump heating device,
A first boiling temperature is calculated according to the required amount of heat to be stored in the tank, and when the calculated first boiling temperature is equal to or lower than a first predetermined temperature (Tst1) set in advance, the first boiling temperature is calculated. The temperature is determined to be the calculated temperature, and the second boiling temperature is determined to be a second predetermined temperature (Tst2) set lower than the first predetermined temperature (Tst1),
When the calculated first boiling temperature is higher than the first predetermined temperature (Tst1), the first boiling temperature is determined as the first predetermined temperature (Tst1), and the second boiling temperature is set as the second boiling temperature. The temperature is determined according to the required amount of heat.

  In general, the efficiency of the heat pump type heating device tends to decrease as the temperature of hot water to be heated during the boiling operation increases. In other words, the efficiency of the heat pump type heating device decreases when the hot water stored in the tank is boiled again. Therefore, according to the present invention, when the first boiling temperature calculated according to the required heat amount is equal to or lower than the first predetermined temperature, the first boiling temperature is determined to be the calculated temperature, and the second boiling temperature is determined. In order to determine the raised temperature as the second predetermined low temperature, hot water corresponding to the required amount of heat can be stored in the upper part of the tank, and hot water set at a low temperature in advance can be stored in the lower part of the tank. . Conversely, when the calculated first boiling temperature is higher than the first predetermined temperature, the first boiling temperature is determined to be the first predetermined temperature, and the second boiling temperature is set according to the required heat amount. In order to determine the calculated temperature, the temperature of the boiling water to be stored in the upper part of the tank is suppressed and the efficiency of the heat pump type heating device is suppressed, and the lower part of the tank corresponds to the required heat quantity. You can store hot water at a certain temperature. Therefore, it is possible to obtain a hot water supply apparatus that sets the first boiling temperature and the second boiling temperature that can secure the necessary amount of heat in the tank and reduce the temperature of the hot water stored in the lower side of the tank. .

  According to the second aspect of the present invention, the second predetermined temperature (Tst2) is a minimum boiling temperature determined in advance according to the specifications of the hot water supply apparatus. According to the present invention, it is possible to suppress the temperature rise of hot water stored in the lower part of the tank, and to reduce the temperature of hot water heated by the heat pump heating device during the boiling operation as much as possible. A possible hot water supply device is obtained.

  According to the third aspect of the present invention, the first predetermined temperature (Tst1) is a maximum boiling temperature determined in advance according to the specifications of the hot water supply apparatus. According to the present invention, since the first predetermined temperature is set high, the second boiling temperature can be determined as low as possible even when the required amount of heat is large. A hot water supply apparatus capable of reducing the temperature of the hot water supply water to be raised as much as possible is obtained.

  According to invention of Claim 4, the heat exchange apparatus (72) is arrange | positioned inside the tank (10), The intermediate part (10c1) of a tank is the arrangement | positioning position of the said heat exchange apparatus (72). It is characterized by being arranged at a lower position than. According to the present invention, the hot water that satisfies the determined first boiling temperature is supplied to the upper part of the tank, so that the temperature of the hot water in the vicinity of the heat exchange device for heating the external fluid is maintained at a high temperature. On the other hand, a hot water supply apparatus capable of filling low temperature hot water with suppressed temperature is obtained on the lower side in the tank.

According to the invention described in claim 5, the heat exchange device (73) is disposed outside the tank (10), and includes a circuit (74) that communicates the heat exchange device and the inside of the tank,
The middle part (10c1) of the tank is characterized in that the hot water supply water in the tank is arranged at a position lower than the tank outflow part (74a) of the circuit toward the heat exchange device (73).

  According to the present invention, hot water satisfying the determined first boiling temperature is supplied to the upper part of the tank, so that the temperature of the hot water supply around the tank outlet for heating the external fluid is maintained at a high temperature. On the other hand, a hot water supply apparatus capable of filling low temperature hot water with suppressed temperature is obtained on the lower side in the tank.

The invention related to the hot water supply apparatus according to claim 6 includes a tank (10) for storing hot water for use in hot water supply, a heat pump heating device (20) for heating hot water taken from the lower side of the tank, and a tank. A heat exchange device (72) that heats the external fluid by exchanging heat between the hot water supply water in the tank and a predetermined external fluid, and hot water boiled by the heat pump heating device from above the tank. An upper inflow means (21, 24) for flowing into the tank, a first boiling temperature and a second boiling temperature lower than the first boiling temperature are determined, and a heat pump type is used so as to satisfy the determined temperature A control device (40) for controlling the operation of the heating device (20),
When the controller (40) performs the boiling operation by the heat pump type heating device,
A first boiling temperature is calculated according to the required amount of heat to be stored in the tank, and when the calculated first boiling temperature is equal to or lower than a first predetermined temperature (Tst1) set in advance, the first boiling temperature is calculated. The temperature is determined to be the calculated temperature, and the second boiling temperature is determined to be a second predetermined temperature (Tst2) that is set lower than the first predetermined temperature (Tst1),
When the calculated first boiling temperature is higher than the first predetermined temperature (Tst1), the first boiling temperature is determined as the first predetermined temperature (Tst1) and the second boiling temperature is required. Determine the temperature calculated according to the amount of heat,
The hot water boiled up to the second boiling temperature determined by the upper inflow means (21, 24) flows into the tank, and then the hot water boiled up to the first boiling temperature determined in the tank is put into the tank. The operation of the heat pump heating device (20) is controlled so as to flow in.

  According to the present invention, the hot water previously heated to the second boiling temperature is supplied from the upper part of the tank, and then heated to the first boiling temperature determined to be higher than the second boiling temperature. Supply hot water. For this reason, high temperature hot water exists on the upper side and low temperature hot water exists on the lower side in the tank. Therefore, it is possible to obtain a hot water supply apparatus that can secure the necessary amount of heat in the tank and reduce the temperature of hot water stored in the lower side of the tank.

  Similarly to the first aspect of the invention, when the first boiling temperature calculated according to the required heat quantity is equal to or lower than the first predetermined temperature, the first boiling temperature is determined as the calculated temperature. At the same time, in order to determine the second boiling temperature as the second predetermined low temperature, hot water corresponding to the required amount of heat is stored in the upper part of the tank, and hot water set in advance in the lower part of the tank. Can be stored. Conversely, when the calculated first boiling temperature is higher than the first predetermined temperature, the first boiling temperature is determined to be the first predetermined temperature, and the second boiling temperature is set according to the required heat amount. In order to determine the calculated temperature, the temperature of the boiling water to be stored in the upper part of the tank is suppressed and the efficiency of the heat pump type heating device is suppressed, and the lower part of the tank corresponds to the required heat quantity. You can store hot water at a certain temperature.

  In addition, the code | symbol in the bracket | parenthesis of each said means has shown the correspondence with the specific means as described in embodiment mentioned later.

It is a schematic diagram which shows the structure of the hot water supply apparatus which concerns on 1st Embodiment to which this invention is applied. It is a flowchart which shows the process sequence of the boiling operation in the hot water supply apparatus of 1st Embodiment. It is a characteristic view which shows the relationship between the required heat amount in the calculation of step 1 of FIG. 2, and the 1st boiling temperature T1 and the 2nd boiling temperature T2. It is a flowchart which shows the process sequence which determines the 1st boiling temperature T1 and the 2nd boiling temperature T2 in the calculation of step 1 of FIG. It is a schematic diagram which shows the structure of the hot water supply apparatus which concerns on 2nd Embodiment to which this invention is applied. It is a schematic diagram which shows the structure of the hot water supply apparatus which concerns on 3rd Embodiment to which this invention is applied. It is a flowchart which shows the process sequence of the boiling operation in the hot water supply apparatus of 3rd Embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly indicate that each embodiment can be specifically combined, but also combinations of the embodiments even if they are not clearly indicated unless there is a problem with the combination. Is also possible.

(First embodiment)
A first embodiment to which the present invention is applied will be described below. The structure of the hot water supply apparatus 100 according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram showing the configuration of the hot water supply apparatus 100.

  As shown in FIG. 1, a hot water supply apparatus 100 includes a heat pump unit 20 as a heat pump heating apparatus that heats water flowing in a circuit 21 and a branch pipe 23 that send water in the lowermost part of the tank 10 into the tank 10, and A tank unit including a tank 10 to which water is supplied to the lowermost portion thereof by a water supply pipe 11a, various pipes 12, 17, 18, various valves and the like, and a control device 40 for controlling the operation of the hot water supply apparatus 100 are provided. . The tank unit and the heat pump unit 20 are configured such that they can be installed integrally or separated from each other at the installation site. Further, the reheating operation is performed by the reheating device 70 configured to exchange heat between the bath water (an example of the external fluid) in the bathtub 82 and the hot water in the tank 10.

  The tank 10 is a container for storing hot water used for hot water supply. The tank 10 is a metal container having excellent corrosion resistance, for example, stainless steel, and a heat insulating material (not shown) is disposed on the outer peripheral portion. You can keep warm over time.

  The tank 10 has a substantially cylindrical shape, and an introduction port 10a is provided on the bottom surface thereof. An introduction pipe 11 as an introduction flow path for supplying tap water into the tank 10 is connected to the introduction port 10a. The introduction pipe 11 is provided with a water supply thermistor 51 and a flow rate counter (not shown). The feed water thermistor 51 outputs an electric signal for detecting the temperature in the introduction pipe 11 to the control device 40, and the flow rate counter outputs an electric signal for detecting the flow rate in the introduction pipe 11 to the control device 40. In addition, a pressure reducing check valve (not shown) is provided on the upstream side of the introduction port 10a to reduce the water pressure of the tap water flowing through the introduction pipe 11 to a predetermined pressure and to prevent the back flow of hot water in the case of water interruption. It has been.

  The introduction pipe 11 is provided with a water supply pipe 11a that branches from a portion upstream of the introduction port 10a. The downstream end of the water supply pipe 11 a is connected to a hot water mixing valve 15 and a bath mixing valve 16.

  A high temperature outlet 10b is provided at the uppermost portion of the tank 10, and the high temperature outlet 10b serves as a hot water supply passage for extracting hot hot water out of hot water stored in the tank 10. A high temperature take-out pipe 12 is connected. Further, a discharge pipe provided with a relief valve (not shown) is connected in the middle of the path of the high temperature take-out pipe 12, and when the pressure in the tank 10 rises above a predetermined pressure, the tank 10 The hot water inside is discharged to the outside so as not to damage the tank 10 or the like.

  One end of the intermediate pipe 10c is connected to the intermediate part 10c1 of the tank, and the other end of the intermediate pipe 10c is connected to the branch pipe 23. The intermediate part 10c1 of the tank is more than a part where the hot water for heat exchange with the bath water (an example of the external fluid) in the bathtub 82 is stored in the tank 10 (the region between the alternate long and short dash lines in the tank 10 shown in FIG. 1). It is provided in the lower part.

  A plurality (seven in this example) of tank water temperature thermistors 55a to 55g as hot water storage temperature detecting means for detecting the amount of hot water storage and the temperature of hot water storage are provided on the outer wall surface of the tank 10 in the vertical direction (the height of the tank 10). Are arranged at substantially equal intervals. The tank water temperature thermistors 55 a to 55 g are configured to output to the control device 40 temperature signals at various water level levels of hot water supply water filled in the tank 10.

  Based on the temperature information transmitted from the tank water temperature thermistors 55a to 55g, it is possible to detect the temperature boundary position between the heated water heated in the upper part of the tank 10 and the water before heated in the lower part of the tank. The amount of stored hot water can be detected. For example, when the detected temperature of a certain tank water temperature thermistor exceeds a predetermined temperature that can be used as the amount of stored hot water, hot water that can be used for hot water is stored from the top of the tank 10 to the position of the tank water temperature thermistor. Become.

  Of these tank water temperature thermistors 55a to 55g, the tank water temperature thermistor 55a is positioned above the reheating heat exchanger 72 (an example of the heat exchange device in the present invention) installed in the tank 10. And has a function of a hot water thermistor that detects the hot water temperature at the uppermost part in the tank 10, which is the temperature of the hot water sucked into the high temperature take-out pipe 12. The tank water temperature thermistor 55b is disposed at substantially the same height as or below the lower end of the reheating heat exchanger 72, and also has a function of a hot water thermistor that detects the hot water temperature derived from the intermediate pipe 10c. .

  A lower portion of the tank 10 is provided with a suction port 10d for sucking the lowermost hot water supply water in the tank 10 into the heat pump unit 20 side. In the upper part of the tank 10, a discharge port 10 e is provided for hot water discharged from the heat pump unit 20 side to flow into the inside. The suction port 10 d and the discharge port 10 e are connected by a circuit 21, and a part of the circuit 21 is a water side passage 26 b of the water / refrigerant heat exchanger 26 in the heat pump unit 20. A portion of the circuit 21 that has passed through the heat pump unit 20 functions as an upper inflow pipe through which high-temperature hot water heated by the heat pump unit 20 flows into the tank 10.

  A heat pump outlet three-way valve 22 (hereinafter referred to as an HP outlet three-way valve 22) is provided between the heat pump unit 20 and the discharge port 10e in the circuit 21. The HP outlet three-way valve 22 functions as a switching valve that switches between flowing hot water boiled by the heat pump unit 20 to the discharge port 10 e side of the tank 10 or flowing to the branch pipe 23. The HP outlet three-way valve 22 is electrically connected to the control device 40 and is controlled based on a temperature signal detected by the tank water temperature thermistors 55a to 55g.

  The other end of the branch pipe 23 branched from the circuit 21 is connected to the intermediate temperature mixing valve 14. The branch pipe 23 is connected to the intermediate pipe 10c on the way. Among the branch pipes 23, the upstream side part 23a of the part connected to the intermediate part pipe 10c functions as an intermediate inflow pipe through which hot water heated by the heat pump unit 20 flows into the tank 10 via the intermediate part pipe 10c. To do. Of the branch pipe 23, the downstream part 23 b of the part connected to the intermediate part pipe 10 c functions as an intermediate outlet pipe through which intermediate temperature hot water flows out of the tank 10 through the intermediate part pipe 10 c.

  The heat pump unit 20 includes a heat pump cycle 20A that uses carbon dioxide having a low critical temperature as a refrigerant, and a feed water pump 24 installed in the circuit 21. According to the supercritical heat pump cycle, hot water having a temperature higher than that of a general heat pump cycle, for example, about 85 ° C. to 90 ° C. can be stored in the hot water storage tank 10.

  The heat pump cycle 20A includes at least an electric compressor 25, a water / refrigerant heat exchanger 26 that is a heat exchanger for heating, an electric expansion valve 27, an air heat exchanger 28, and a refrigeration cycle functional component of an accumulator 29. It is formed by being connected in an annular shape by piping. Further, a blower 28 a that provides forced air to the air heat exchanger 28 is provided in the vicinity of the air heat exchanger 28.

  The heat pump unit 20 is configured to be operated by a control signal from the control device 40 and to display the operating state on the operation panel 41. The heat pump unit 20 performs a boiling operation to boil hot water in the tank 10 mainly by controlling the rotational speed of the compressor 25 using late-night power in the late-night time period, which is inexpensive, and at other times than the late-night time period. Even in the time zone, when the amount of stored hot water in the tank 10 becomes insufficient, the boiling operation is performed. Further, the rotational speed of the compressor 25 is controlled by the control device 40 so that a prescribed capacity is obtained under various operating conditions.

  The expansion valve 27 is a decompression unit that decompresses the high-pressure refrigerant flowing out of the water / refrigerant heat exchanger 26, and the valve opening degree is electrically controlled by the control device 40. The air heat exchanger 28 evaporates and evaporates the refrigerant decompressed by the expansion valve 27 by heat exchange with the outdoor air blown by the blower 28a, and supplies the gas refrigerant to the compressor 25. The rotational speed of the blower 28a is controlled by the control device 40 so as to ensure the heat exchange performance of the air heat exchanger 28. The accumulator 29 gas-liquid separates the refrigerant flowing out from the air heat exchanger 28, causes only the gas-phase refrigerant to be sucked into the compressor 25, and stores excess refrigerant in the cycle.

  The water / refrigerant heat exchanger 26 is a heat exchanger that heats water with hot and high-pressure refrigerant discharged from the discharge port of the compressor 25 to form hot water. The refrigerant-side passage 26a of the water / refrigerant heat exchanger 26 is configured by a refrigerant flow pipe that exchanges heat between the high-pressure gas refrigerant discharged from the discharge port of the compressor 25 and the hot-water supply water flowing through the water-side passage 26b. Yes. The water / refrigerant heat exchanger 26 has a two-layer structure in which the refrigerant-side passage 26a and the opposite surface of the water-side passage 26b are in close contact with each other so as to allow heat exchange. The water side passage 26b is configured such that heat exchange between the refrigerant and the water flowing through the circuit 21 is performed over the entire length of the refrigerant flow path from the refrigerant inlet portion to the refrigerant outlet portion of the refrigerant side passage 26a. And when warm water equivalent to predetermined boiling temperature (about 65 degreeC-90 degreeC) is taken out from the exit part of the water side channel | path 26b, it is comprised so that a regular heat exchange performance can be taken out.

  A water supply pump 24 is disposed between the suction port 10d of the circuit 21 and the water side passage 26b. The water supply pump 24 is rotationally driven by a built-in electric motor, and sucks hot water in the tank 10 from the suction port 10d and heats it in the water side passage 26b during the boiling operation, and then discharges the water 10 in the discharge port 10e of the tank 10. Or it act | operates so that it may recirculate | reflux to the intermediate part piping 10c. The rotation speed of the feed water pump 24 is controlled by the control device 40 so that the outlet side water temperature of the water side passage 26b becomes a predetermined target boiling temperature determined under various operating conditions.

  The circuit 21, the heat pump outlet three-way valve 22, and the water supply pump 24 are an example of the upper inflow means of the present invention, and hot water boiled to the first boiling temperature T 1 by the heat pump unit 20 is supplied from the upper part of the tank 10 to the tank 10. It has a function to flow in. The circuit 21, the heat pump outlet three-way valve 22, the branch pipe 23, the intermediate pipe 10 c, and the feed water pump 24 are examples of the intermediate part inflow means of the present invention, and are heated to the second boiling temperature T <b> 2 by the heat pump unit 20. It has a function of causing hot water to flow into the tank 10 from a portion below the portion where hot water for heat exchange with the external fluid is stored in the tank 10.

  The incoming water temperature thermistor 31 outputs an electrical signal for detecting the temperature of the hot water supplied to the water / refrigerant heat exchanger 26. The boiling temperature thermistor 32 outputs an electrical signal for detecting the boiling temperature at the outlet of the water / refrigerant heat exchanger 26. The discharged refrigerant temperature thermistor 33 outputs an electric signal for detecting the temperature of the refrigerant discharged from the compressor 25. The outlet refrigerant temperature thermistor 34 outputs an electrical signal for detecting the refrigerant temperature at the outlet of the water / refrigerant heat exchanger 26. Any of the thermistors 31 to 34 outputs an electric signal to the control device 40. Further, the pressure sensor 35 outputs an electric signal for detecting the refrigerant pressure at the outlet of the refrigerant side passage 26 a to the control device 40.

  The intermediate temperature mixing valve 14 is provided at a junction of the high temperature take-out pipe 12 and the branch pipe 23. The intermediate temperature mixing valve 14 adjusts the respective opening area ratios of the high temperature side high temperature take-out pipe 12 and the branch pipe 23 connected to the intermediate temperature side intermediate pipe 10c, so that the hot water taken out from the high temperature take-out pipe 12 is adjusted. By adjusting the mixing ratio of the hot water extracted from the intermediate pipe 10c and the intermediate temperature hot water, the temperature of the hot water flowing through the hot water supply pipe 17, the hot water supply mixing valve 15, the bath mixing valve 16, the bath pipe 18 and the like is adjusted. It is a temperature control valve to adjust.

  The intermediate temperature mixing valve 14 is controlled by the control device 40 based on temperature signals detected by the tank water temperature thermistors 55 a to 55 g and the hot water temperature thermistor 52. The hot water temperature thermistor 52 is provided on the outlet side of the intermediate temperature mixing valve 14 and detects the temperature of the hot water mixed by the intermediate temperature mixing valve 14. Here, the temperature detected by the hot water temperature thermistor 52 is a predetermined temperature. (For example, the set temperature set by the user on the operation panel 41 is about +2 to 5 ° C.) The medium-temperature hot water taken out from the intermediate pipe 10c is mixed with the high-temperature hot water in the tank 10 to reach the predetermined temperature. The temperature is adjusted.

  The hot water thermistor 52 is provided on the outlet side of the intermediate temperature mixing valve 14 and detects the temperature of the hot water mixed by the intermediate temperature mixing valve 14. Connected to the outlet side of the intermediate temperature mixing valve 14 are a hot water supply pipe 17 as a hot water supply flow path and a bath pipe 18 as a hot water filling pipe branched from the hot water supply pipe 17.

  The hot water supply pipe 17 is a pipe that guides hot water whose temperature is adjusted to a set temperature to a hot water tap 81 (curan, shower, etc.) as a terminal at the downstream end thereof. In the middle of the flow path, a hot water supply mixing valve 15 as a temperature adjusting means and a hot water supply thermistor 53 as a temperature detecting means are provided. The hot water supply thermistor 53 outputs an electric signal for detecting the temperature in the hot water supply pipe 17 downstream of the hot water supply mixing valve 15 to the control device 40.

  The bath pipe 18 is connected to the adapter 82a of the bathtub 82 at the downstream end thereof, and guides hot water whose temperature is adjusted to a set temperature when hot water is filled in the bathtub 82, hot water, hot water, or the like. is there. In the middle of the flow path, bath mixing valve 16, bath thermistor 54, hot water solenoid valve 61, hot water flow counter 62, check valve 63, circulating temperature thermistor 56, flow switch 64, bath three-way valve 65, a chasing thermistor 57 is provided.

  The hot water mixing valve 15 and the bath mixing valve 16 are temperature control valves that adjust the temperature of the hot water discharged at the ends of the hot water supply pipe 17 and the bath pipe 18, respectively. The temperature of the hot water to be discharged is adjusted to a set temperature by adjusting the ratio of the opening on the hot water supply side adjusted in temperature by the valve 14 and the opening on the hot water supplied from the water supply pipe 11a.

  The operation of the hot water mixing valve 15 and the bath mixing valve 16 is controlled by the control device 40 based on electrical signals relating to the temperatures detected by the hot water thermistor 51, the hot water temperature thermistor 52, the hot water thermistor 53, and the bath thermistor 54. The

  The bath thermistor 54 outputs an electrical signal for detecting the temperature in the bath pipe 18 downstream of the bath mixing valve 16 to the control device 40. The hot water solenoid valve 61 is a valve that opens and closes the flow path of the bath pipe 18, and is controlled by the control device 40 when hot water is filled into the bathtub 82, hot water, and hot water. The hot water flow rate counter 62 detects the flow of hot water in the bath pipe 18 and outputs a detection signal to the control device 40. When the hot water flow rate counter 62 detects the flow of hot water in the bath pipe 18, it indicates that the hot water solenoid valve 61 of the bath pipe 18 is opened and discharged.

  The check valve 63 is a valve for preventing the bath water flowing through the forward pipe 66 from flowing backward to the bath mixing valve 16 side. The circulation temperature thermistor 56 outputs an electrical signal for detecting the temperature of the bath water circulating in the bath pipe 18, the bathtub 82, and the forward pipe 66 connected to the adapter 82 a of the bathtub 82 to the control device 40. The flow switch 64 is a water flow sensor that can detect whether hot water or bath water is flowing in the direction toward the bath three-way valve 65.

  The bath three-way valve 65 is a flow path switching valve for flowing bath water (an example of a predetermined external fluid in the present invention) from the bathtub 82 and the forward pipe 66 to either the reheating heat exchanger 72 side or the bathtub 82 side. Yes, it is controlled by the control device 40. The reheating thermistor 57 controls the electric signal for detecting the temperature of the bath water circulating in the circuit formed by the forward pipe 66, the bath pipe 18, the bath water circulation circuit 71, and the reheating heat exchanger 72. Output to.

  The reheating device 70 passes from the bath three-way valve 65 through the upper part of the tank 10 and is connected to the adapter 82 a side of the bath piping 18, and the reheating heat connected in the middle of the bath water circulation circuit 71. The exchanger 72 and the forward pipe 66 connected between the adapter 82a and the check valve 63 and the flow switch 64 are configured. The reheating heat exchanger 72 according to the present embodiment is formed in a coil shape, and is disposed at an upper portion in the tank 10, so that hot water stored in the tank 10 is stored in the tank 10. It is a heat exchanger heated by (hot water stored in the area | region between the dashed-dotted lines in the tank 10 shown in FIG. 1).

  The inflow portion and the outflow portion of the reheating heat exchanger 72 are connected to the wall surface of the tank 10 on the same side, and the reheating heat exchanger 72 is disposed at a position shifted from the axial center of the tank 10. . The intermediate pipe 10c is connected to the wall surface of the tank 10 on the side where the reheating heat exchanger 72 is disposed. Further, the intermediate pipe 10 c is connected below the lower end of the reheating heat exchanger 72.

  The forward pipe 66 is provided with a water level sensor 67, a bath circulation electric valve 68, and a bath circulation pump 69 in order from the adapter 82a toward the downstream side of the circulating water. The water level sensor 67 is a sensor that detects the amount of hot water in the bath 82 filled with hot water, in other words, a water pressure for obtaining the water level in the bathtub 82, and outputs a water pressure signal to the control device 40. ing. The bath circulation electric valve 68 is an electric valve that opens and closes the forward pipe 66, and the bath circulation pump 69 is an electric pump that pumps the bath water in the bathtub 82 to the reheating heat exchanger 72, both of which are controlled by the control device 40. Its operation is controlled.

  When the bath water temperature in the bathtub 82 is detected during or after the hot water filling, the bath water in the bathtub 82 is switched by switching the bath three-way valve 65 to the bath piping 18 side and operating the bath circulation pump 69. Is circulated in the order of the forward pipe 66, the bath pipe 18, and the bathtub 82, and the temperature of the bath water is detected by the circulation temperature thermistor 56.

  When reheating, the bath three-way valve 65 is switched to the bath water circulation circuit 71 side, so that the bath water in the bathtub 82 flows in the forward pipe 66, the bath water circulation circuit 71, the reheating heat exchanger 72, and the bath water circulation circuit 71. Circulation of the bath 18 and the bathtub 82 are circulated in this order, and the circulation control is continued until the bath water temperature detected by the circulation temperature thermistor 56 reaches a predetermined temperature.

  The control device 40 is mainly composed of a microcomputer, and a control program is stored in advance in a built-in ROM. The temperature signals from the thermistors 31 to 34 and 51 to 57, the pressure signals from the pressure sensor 35, Flow rate signal from the water filling flow counter 62, bath water flow signal from the flow switch 64, water level signal from the water level sensor 67, input from the operation panel 41 (for example, remote control installed in the bath, remote control installed in the kitchen) input by the user Based on the signal or the like, the various mixing valves 14 to 16, the heat pump unit 20, the HP outlet three-way valve 22, the hot water solenoid valve 61, the bath three-way valve 65, the bath circulation electric valve 68, and the bath circulation pump 69 are controlled. It is configured.

  Moreover, the control apparatus 40 memorize | stores the performance (for example, the driving | operation performance of the heat pump unit 20, the hot_water | molten_metal supply performance corresponding to hot water supply, hot water filling, etc.) of the used heat amount used as warm water every day in a memory | storage means. The storage means is composed of, for example, a flash memory or a RAM, and reads and writes stored data. The storage means can store, for example, a past record of the amount of heat used including the operation result of the heat pump unit 20 for a predetermined period, and an old result that protrudes from the predetermined period is rewritten as needed with a new result. In the present embodiment, the record of the amount of heat used for the past one week is stored as an example of the predetermined period. Then, when the record of the amount of heat used for one week is the timing at which the latest one-day record is stored, the oldest one-day record is erased from the storage means, and the most recent one-day record is written. Become.

  The operation panel 41 is provided with a hot water supply set temperature switch, a hot water switch, a hot water set temperature switch, a reheating switch, a reheating set temperature switch, and the like as operation switches. The operation panel 41 is installed in the vicinity of a place where hot water is used, such as in a bathroom or kitchen, and the operation panel 41 other than the operation panel 41 is installed in a suitable place such as outdoors.

  The operation at the time of boiling operation in the hot water supply apparatus 100 will be described with reference to FIGS. FIG. 2 is a flowchart showing the processing procedure of the boiling operation. This flowchart is executed by the control device 40. When there is an instruction to start the boiling operation, the control device 40 executes calculations for obtaining various conditions necessary for performing the boiling operation in Step 1. This calculation process is a process for determining the first boiling temperature T1 and the second boiling temperature T2 in accordance with the required amount of heat to be stored in the tank 10, and the detailed processing procedure will be described later.

  The first boiling temperature T <b> 1 is a temperature at which hot water that flows into the tank 10 from the discharge port 10 e (upper part of the tank 10) of the tank 10 is heated by the heat pump unit 20. The second boiling temperature T2 is a temperature at which hot water flowing into the tank 10 from the intermediate portion 10c1 of the tank is boiled by the heat pump unit 20, and is determined to be lower than the first boiling temperature T1.

  When the calculation for determining the first boiling temperature T1 and the second boiling temperature T2 is completed in step 1, the control device 40 determines whether the hot water heated by the heat pump unit 20 is the first boiling temperature T1 determined in step 1. The boiling operation which controlled the action | operation of the heat pump unit 20 is implemented so that it may become (step 2). In step 3, the discharge port 10 e side of the HP outlet three-way valve 22 is opened, hot water in the tank 10 is circulated to the circuit 21, and hot water heated by the heat pump unit 20 (first boiling temperature T 1) is supplied. It accumulates from the upper part of the tank 10 through the discharge port 10e.

  Next, in step 4, the temperature detected by the tank water temperature thermistor 55b disposed below the reheating heat exchanger 72 is slightly lower than the first boiling temperature T1 (for example, (T1-α ) Determine whether or not it is higher than ° C). If it is determined in step 4 that the detected temperature has increased, then in step 5, the control device 40 raises the target boiling to the second boiling temperature T <b> 2 determined in step 1 lower than the first boiling temperature T <b> 1. The operation of the heat pump unit 20 is controlled so as to reduce the temperature and generate hot water.

  In step 6, the HP outlet three-way valve 22 is switched so as to open the intermediate pipe 10 c side, and the water heated to the second boiling temperature T 2 flows into the tank 10 from below the reheating heat exchanger 72. To do. Next, in step 7, the detected temperature of any of the tank water temperature thermistors 55c to 55g located below the intermediate portion 10c1 of the tank is slightly lower than the second boiling temperature T2 (for example, (T2-β) It is judged whether it became higher than (C). If it is determined in step 7 that the detected temperature has increased, it is determined that the boiling operation has been completed. In step 8, the operation of the heat pump unit 20 is terminated, and this flowchart is terminated.

  Next, a specific calculation procedure of Step 1 will be described below with reference to FIGS. FIG. 3 is a characteristic diagram showing the relationship between the required amount of heat in the calculation of step 1 and the first and second boiling temperatures T1 and T2. FIG. 4 is a flowchart showing a processing procedure for determining the first boiling temperature T1 and the second boiling temperature T2 in the calculation of Step 1.

  As shown in FIG. 3, the control device 40 determines the first boiling temperature in accordance with the required amount of heat to be stored in the tank 10, which is obtained based on the predicted amount of hot water used calculated from the actual usage of hot water in the past predetermined period. T1 and the second boiling temperature T2 are respectively determined. In step 1, the control device 40 determines that the first boiling temperature T1 does not exceed a predetermined first predetermined temperature Tst1. The first predetermined temperature Tst1 is the highest temperature (for example, 85 ° C.) as the hot water heated by the heat pump unit 20.

  That is, even if the necessary heat amount to be stored in the tank 10 is equal to or higher than the predetermined heat amount, the first boiling temperature T1 is maintained at the first predetermined temperature Tst1 at the maximum. Further, the first boiling temperature T1 is determined so as to increase in proportion to the required heat amount when the required heat amount is less than the predetermined heat amount. However, at this time, the control device 40 does not increase the second boiling temperature T2 and keeps the second low predetermined temperature Tst2 (for example, a predetermined low temperature) (for example, when the required heat amount is large but less than the predetermined heat amount). 65 ° C.).

  On the other hand, when the required heat quantity exceeds the predetermined heat quantity, the control device 40 determines the first boiling temperature T1 as the first predetermined temperature Tst1, and the heat quantity stored in the tank 10 is largely insufficient. In order to reduce this, the second boiling temperature T2, which is the hot water temperature flowing into the intermediate portion 10c1 of the tank, is determined to be higher than the second predetermined temperature Tst2.

  As described above, when the necessary heat amount is equal to or less than the predetermined heat amount, the control device 40 determines the second boiling temperature T2 to be low, and suppresses the hot water temperature flowing into the intermediate portion 10c1 of the tank as much as possible. Control. Further, since the hot water at the first boiling temperature T1 increased in proportion to the required heat amount is supplied to the region from the uppermost part of the tank 10 to the tank water temperature thermistor 55b, the amount of stored hot water is ensured. While storing hot water at which the reheating operation can be performed in the area where the exchanger 72 is disposed, excessive hot water is not boiled and stored without boiling excessively hot water with respect to the expected amount of hot water used. The heat dissipation loss due to can be reduced.

  In the region below the tank water temperature thermistor 55b, in order to store hot water at the second boiling temperature T2 determined to be as low as possible, a boiling operation is performed in which the entire amount in the tank 10 is stored with hot water. In comparison with this, the coefficient of performance (COP) of the heat pump unit 20 can be improved, and a highly efficient boiling operation can be performed.

  The second predetermined temperature Tst2 is preferably a minimum boiling temperature determined in advance according to the specifications of the hot water supply device 100. Moreover, it is preferable that 1st predetermined temperature Tst1 is the highest boiling temperature predetermined by the specification of the hot water supply apparatus 100. FIG. The minimum boiling temperature or the maximum boiling temperature determined by the specifications of the hot water supply apparatus 100 can be paraphrased as, for example, the temperature determined by the heating performance specific to the system of the heat pump unit 20.

  As shown in FIG. 4, when the calculation process of the boiling operation in Step 1 is started, the control device 40 calculates the necessary heat amount in Step 11. Then, in step 12, the second boiling temperature T2 is set to the second predetermined temperature Tst2, and the first heating temperature is calculated using the necessary amount of heat calculated in step 11 and the second boiling temperature T2 set in step 12. T1 is calculated (step 13).

  Next, in step 14, it is determined whether or not the first boiling temperature T1 calculated in step 13 is equal to or lower than a first predetermined temperature Tst1. If it is determined in step 14 that the calculated first boiling temperature T1 is equal to or lower than the first predetermined temperature Tst1, then in step S15, the control device 40 sets the second boiling temperature T2 to the second low temperature. The predetermined temperature Tst2 is determined, and this calculation routine ends. In this case, the first boiling temperature T1 is determined to be equal to or lower than the first predetermined temperature Tst1, and the second boiling temperature T2 is determined to be the second predetermined temperature Tst2.

  On the other hand, if it is determined in step 14 that the calculated first boiling temperature T1 is not equal to or lower than the first predetermined temperature Tst1, the control device 40 subsequently determines that the first boiling temperature T1 is set to a high temperature in step S16. 1 is determined to be a predetermined temperature Tst1, and in step 17, the second boiling temperature T2 is determined to be a value calculated based on the necessary heat quantity, and this calculation routine is terminated. In this case, the first boiling temperature T1 is determined to be the first predetermined temperature Tst1 at the maximum, and the second boiling temperature T2 is determined to be equal to or higher than the second predetermined temperature Tst2 calculated based on the necessary heat amount. It will be.

  Next, the operation when using hot water is described. When hot water is used during the daytime or the like, the intermediate pipe 10c of the intermediate temperature mixing valve 14 is opened, and hot water stored in the intermediate part 10c1 of the tank is preferentially taken out so that the hot water mixing valve 15 matches the set temperature. The bath mixing valve 16 is used by mixing with hot water by adjusting the valve opening.

  However, when the amount of hot water in the tank 10 decreases to some extent, the heat pump unit 20 is operated to boil high-efficiency low-temperature hot water, the branch outlet 23 side of the HP outlet three-way valve 22 is opened, and low-temperature hot water is placed in the middle of the tank. Hot water is stored in the part 10c1. After the boiling is stabilized by the heat pump unit 20, low temperature hot water heated from the heat pump unit 20 through the downstream portion 23b of the branch pipe 23 is used as the hot water.

  Moreover, when the flow rate of the hot water heated by the heat pump unit 20 is insufficient, the hot water in the intermediate portion 10c1 of the tank is also mixed and used at the same time. Further, when the hot water from the tank intermediate portion 10c1 cannot be adjusted to the set temperature, the hot water at the upper portion of the tank 10 is also used by increasing the opening degree of the intermediate temperature mixing valve 14 on the high temperature take-out pipe 12 side. Secure.

  Next, the chasing operation will be described. For example, when the bath water temperature detected by the circulating temperature thermistor 56 becomes lower than the set temperature during the heat insulation operation, or when the user instructs the reheating operation by operating the operation panel 41, the reheating operation is performed. carry out. When the control device 40 has a command for carrying out the reheating operation, the detection temperature of the tank water temperature thermistor 55b is a temperature at which reheating can be performed so that the bath water is set to a temperature set within a predetermined time. Determines that the reheating operation can be performed with the hot water stored in the upper part of the tank 10.

  Then, the bath three-way valve 65 is opened on the bath water circulation circuit 71 side, the bath circulation pump 69 is operated, and the bath water in the bathtub 82 flows into the bath water circulation circuit 71. The bath water that has flowed into the bath water circulation circuit 71 flows into the tank 10 via the inflow portion of the reheating heat exchanger 72 and is heated by exchanging heat with the hot water stored in the tank 10. The heated bath water flows out of the tank 10 through the outflow portion of the reheating heat exchanger 72 and is returned to the bathtub 82 through the bath water circulation circuit 71 and the bath piping 18. When the temperature detected by the circulation temperature thermistor 56 is higher than the set temperature, the bath three-way valve 65 is switched so that the bath water circulation circuit 71 side is closed, and the bath circulation pump 69 is stopped.

  Below, the effect which the hot water supply apparatus 100 of this embodiment brings is demonstrated. In general, the efficiency of the heat pump unit 20 tends to decrease as the temperature of hot water to be heated during the boiling operation increases. That is, the efficiency of the heat pump unit 20 is reduced when the hot water stored in the tank 10 is heated again.

  Therefore, when performing the boiling operation, the control device 40 in the hot water supply device 100 calculates the first boiling temperature T1 according to the necessary heat amount to be stored in the tank 10, and the calculated first boiling temperature is determined in advance. When the temperature is equal to or lower than the first predetermined temperature Tst1, the first boiling temperature T1 is determined to be the calculated temperature, and the second boiling temperature T2 is set to be lower than the first predetermined temperature Tst1. 2 to a predetermined temperature Tst2. When the calculated first boiling temperature T1 is higher than the first predetermined temperature Tst1, the first boiling temperature T1 is determined as the first predetermined temperature Tst1 and the second boiling temperature T2 is set. The temperature is determined according to the required amount of heat.

  According to this, when the 1st boiling temperature T1 calculated according to the said required heat quantity is below 1st predetermined temperature Tst1, while determining the 1st boiling temperature T1 to the said calculated temperature, 2nd In order to determine the boiling temperature T2 as the low second predetermined temperature Tst2, high temperature hot water corresponding to the required heat amount is stored in the upper portion of the tank 10, and the lower boiling temperature is stored in the lower portion of the tank 10. You can store hot water that is kept in low pressure. As a result, when the boiling operation is performed next time, the hot water temperature in the lower part of the tank 10 can be lowered, and the re-boiling of the remaining hot water that has been changed to intermediate temperature water can be suppressed, so that the efficiency (COP) of the heat pump unit 20 is reduced. Can be suppressed.

  Conversely, when the calculated first boiling temperature T1 is higher than the first predetermined temperature Tst1, the first boiling temperature T1 is determined to be the first predetermined temperature Tst1, and the second boiling temperature T2 is determined. Therefore, the temperature of the heat pump unit 20 is suppressed from being lowered by suppressing the temperature of boiling water to be stored in the upper part of the tank 10. Hot water at a temperature corresponding to the required amount of heat can be stored on the lower side.

  In addition, by determining the hot water temperature stored in the upper part of the tank 10 in proportion to the required heat amount, even when the hot water stored in the upper part of the tank 10 is lowered due to the use of hot water supply or reheating operation, Since it can be maintained at a temperature that can be used for hot water supply as it is, it is not subject to re-boiling by the heat pump unit 20. Therefore, it is possible to suppress a decrease in efficiency of the heat pump unit 20.

  In addition, according to the boiling operation in the hot water supply apparatus 100, only the upper side of the tank 10 is heated with hot water when the entire amount of hot water in the tank 10 is boiled up based on the high temperature required for reheating and keeping warm. By satisfying and lowering the boiling temperature of the hot water stored in the lower part of the tank 10, it is possible to suppress a decrease in efficiency of the heat pump unit 20 due to an increase in the boiling temperature.

  In addition, when hot water is used, hot water is discharged while the upper part of the tank 10 is maintained at a high temperature by preferentially using hot water from the intermediate part 10c of the tank by removing hot water from the intermediate part 10c1 of the tank. be able to.

  The second predetermined temperature Tst2 set in advance is preferably a minimum boiling temperature determined in advance by the specifications of the hot water supply apparatus 100. According to this, the hot water supply water stored on the lower side in the tank 10 is used. While being able to suppress a temperature rise, the temperature of the hot water supplied by the heat pump unit 20 during the boiling operation can be reduced as much as possible.

  Moreover, it is preferable that the first predetermined temperature Tst1 that is set in advance is a maximum boiling temperature that is determined in advance according to the specifications of the hot water supply device 100, and according to this, the first predetermined temperature Tst1 is easily set high. Even when the required amount of heat is large, the second boiling temperature T2 can be determined as low as possible. Therefore, it is possible to reduce the temperature of hot water supplied by the heat pump unit 20 during the boiling operation as much as possible.

  Further, the intermediate portion 10c1 of the tank is provided at a position below the position where the reheating heat exchanger 72 is disposed. According to this configuration, hot water satisfying the determined first boiling temperature T1 is supplied to the upper portion of the tank 10, whereby hot water supply water around the reheating heat exchanger 72 for heating the bath water. While maintaining the temperature at a high temperature, the lower side of the tank 10 can be filled with low-temperature hot water with the temperature suppressed. Therefore, it is possible to provide the hot water supply apparatus 100 that is excellent in efficiency of the heat pump unit 20 and suppresses re-boiling of hot water in the tank 10.

(Second Embodiment)
The hot water supply apparatus 100A of the second embodiment is different from the hot water supply apparatus 100 of the first embodiment in that a reheating heat exchanger 73 is provided outside the tank 10. FIG. 5 is a schematic diagram showing a configuration of a hot water supply apparatus 100A according to the second embodiment. In FIG. 5, elements denoted by the same reference numerals as those in FIG. 1 are the same components as those described in the first embodiment, have similar operations and effects, and are further heated (see the flowchart in FIG. 2). ), Operation at the time of hot water supply, operation at the time of hot water supply, calculation processing at the time of boiling operation (characteristic diagram of FIG. 3 and flowchart of FIG. 4) and the like are the same as in the first embodiment. Hereinafter, only a different form from 1st Embodiment is demonstrated about 2nd Embodiment.

  As shown in FIG. 5, the hot water supply device 100 </ b> A includes a reheating heat exchanger 73 disposed outside the tank 10, and a circuit 74 that connects the reheating heat exchanger 73 and the inside of the tank 10. . The circuit 74 is connected from the tank outlet 74a connected to the upper part of the tank 10 (the area between the dashed lines in the tank 10 shown in FIG. 5) to the lower part of the tank 10 (between the tank water temperature thermistors 55f and 55g shown in FIG. 5). This is a path including a piping path leading to the tank inflow portion 74b connected to the tank inflow area) and an internal area of the tank 10 extending from the tank inflow portion 74b to the tank outflow portion 74a.

  In the middle of the piping path of the circuit 74, a hot water supply water side passage 73b in the reheating heat exchanger 73 and a circulation pump 75 for circulating the hot water supply water in the tank 10 to the circuit 74 are provided. Further, a tank intermediate portion 10 c 1 that is a tank connection portion of the intermediate pipe 10 c is provided at a position below the tank outflow portion 74 a of the circuit 74. The reheating device 70A includes a bath water circulation circuit 71A connected to the adapter 82a side of the bath pipe 18 through the bath water side passage 73a in the reheating heat exchanger 73 from the bath three-way valve 65, and the bath water circulation circuit 71A. The reheating heat exchanger 73 is connected in the middle, and the forward pipe 66 is connected between the check valve 63 and the flow switch 64 from the adapter 82a. The reheating heat exchanger 73 is heated by the hot water stored in the tank 10 (hot water stored in the region between the alternate long and short dash lines in the tank 10 shown in FIG. 5). Heat exchanger.

  That is, the hot water stored in the upper part of the tank 10 flows out of the tank outlet 74a of the circuit 74 through the piping path of the circuit 74 by the driving force of the circulation pump 75, and flows in the piping path of the circuit 74. After passing through the hot water supply water side passage 73b, heat is exchanged with the bath water flowing through the bath water side passage 73a to heat the bath water, and then return to the lower part of the tank 10 from the tank inflow portion 74b.

  According to the hot water supply apparatus 100 </ b> A of this embodiment, the reheating heat exchanger 73 is disposed outside the tank 10, and includes a circuit 74 that connects the reheating heat exchanger 73 and the inside of the tank 10. The intermediate portion 10 c 1 of the tank is disposed at a position lower than the tank outlet portion 74 a of the circuit 74 in which hot water in the tank 10 goes to the reheating heat exchanger 73.

  According to this configuration, the hot water satisfying the determined first boiling temperature T1 is supplied to the upper portion of the tank 10, so that the temperature of the hot water supply water in the vicinity of the tank outlet 74a for heating the bath water is increased. While maintaining the temperature, the lower side of the tank 10 can be filled with low-temperature hot water with reduced temperature. Therefore, it is possible to provide a hot water supply apparatus 100A that is excellent in efficiency of the heat pump unit 20 and suppresses reheating of hot water in the tank 10.

(Third embodiment)
The hot water supply apparatus 100B of the third embodiment is different from the hot water supply apparatus 100 of the first embodiment in that it does not have the branch pipe 23 and the HP outlet three-way valve 22, and the tank boiled up by the heat pump unit 20 All the hot water supply water in 10 is returned to the upper part in the tank 10. Furthermore, in the hot water supply device 100B of the third embodiment, the processing procedure of the boiling operation is different from that of the first embodiment due to the difference in the above configuration.

  FIG. 6 is a schematic diagram showing a configuration of a hot water supply apparatus 100B according to the second embodiment. FIG. 7 is a flowchart showing a processing procedure of a boiling operation in hot water supply apparatus 100B. In FIG. 6, elements denoted by the same reference numerals as those in FIG. 1 are the same components as those described in the first embodiment, and have the same operations and effects, and are further driven and operated during hot water supply. The calculation process during the boiling operation (the characteristic diagram of FIG. 3 and the flowchart of FIG. 4) and the like are the same as in the first embodiment. Hereinafter, only a different form from 1st Embodiment is demonstrated about 3rd Embodiment.

  As shown in FIG. 6, the hot water supply device 100B includes a circuit 21 and a water supply pump 24 as an example of the upper inflow means, and has been heated to the first boiling temperature T1 or the second boiling temperature T2 by the heat pump unit 20. A function of allowing hot water to flow into the tank 10 from above the tank 10 is provided.

  Next, the operation at the time of boiling operation in the hot water supply apparatus 100B will be described with reference to FIG. FIG. 7 is a flowchart showing a processing procedure of the boiling operation. This flowchart is executed by the control device 40. When there is an instruction to start the boiling operation, the control device 40 executes calculations for obtaining various conditions necessary for carrying out the boiling operation in Step 20. The calculation process in step 20 is a process for determining the first boiling temperature T1 and the second boiling temperature T2, and is the same as the calculation process described with reference to FIGS. 3 and 4 in the first embodiment. .

  When the calculation for determining the first boiling temperature T1 and the second boiling temperature T2 is completed in step 20, the control device 40 determines whether the hot water heated by the heat pump unit 20 is the second boiling temperature T2 determined in step 20. The boiling operation which controlled the action | operation of the heat pump unit 20 is implemented so that it may become (step 21). Then, hot water in the tank 10 is circulated through the circuit 21 and hot water at the second boiling temperature T2 heated by the heat pump unit 20 is stored in the upper part of the tank 10 from the discharge port 10e.

  Next, in step 22, the temperature detected by the tank water temperature thermistor 55b disposed below the reheating heat exchanger 72 is slightly lower than the second boiling temperature T2 (for example, (T2-α ) Determine whether or not it is higher than ° C). If it is determined in step 22 that the detected temperature has increased, then in step 23, the control device 40 raises the target boiling to the first boiling temperature T1 determined in step 20 to be higher than the second boiling temperature T2. The operation of the heat pump unit 20 is controlled so as to increase the temperature and generate hot water. And the hot water of 1st boiling temperature T1 heated with the heat pump unit 20 is stored in the upper part of the tank 10 from the discharge outlet 10e. For this reason, the low temperature hot water having the second boiling temperature T2 previously stored in the upper part of the tank 10 is pushed down by the high temperature hot water having the first boiling temperature T1. Therefore, a temperature layer is formed in the order of low temperature hot water and high temperature hot water from the lower part to the upper part of the tank 10.

  Next, in step 24, it is determined whether or not the detected temperature of the tank water temperature thermistor 55b is slightly higher than a temperature (for example, (T1-β) ° C.) slightly lower than the first boiling temperature T1. If it is determined in step 24 that the detected temperature has increased, it is determined that the boiling operation has been completed. In step 25, the operation of the heat pump unit 20 is terminated, and this flowchart is terminated.

  Below, the effect which the hot water supply apparatus 100B of this embodiment brings is demonstrated. When performing the heating operation by the heat pump unit 20, the control device 40 of the water heater 100B calculates the first boiling temperature T1 according to the necessary heat amount to be stored in the tank 10, and the calculated first boiling is performed. When the temperature T1 is equal to or lower than a predetermined first predetermined temperature Tst1, the first boiling temperature T1 is determined as the calculated temperature, and the second boiling temperature T2 is lower than the first predetermined temperature Tst1. Is determined to be the second predetermined temperature Tst2. When the calculated first boiling temperature T1 is higher than the first predetermined temperature Tst1, the first boiling temperature T1 is determined as the first predetermined temperature Tst1 and the second boiling temperature T2 is set. The temperature is determined according to the required amount of heat. Further, the control device 40 flows the hot water boiled to the above determined second boiling temperature T2 into the tank 10 by the upper inflow means, and then boiled hot water to the above determined first boiling temperature T1. The operation of the heat pump unit 20 is controlled so as to flow into the tank 10.

  According to this control, after supplying hot water previously heated to the second boiling temperature T2 from the upper part of the tank 10, the first boiling temperature T1 determined to be higher than the second boiling temperature T2. Supply boiling water. For this reason, in the tank 10, the temperature distribution in which high temperature hot water is filled in the upper side and low temperature hot water is filled in the lower side is obtained. Therefore, it is possible to provide a hot water supply device 100B that can secure the necessary amount of heat in the tank 10 and reduce the temperature of hot water stored in the lower side of the tank 10.

  In addition, according to the hot water supply device 100B, the flow path switching means such as the HP outlet three-way valve 22 included in the hot water supply device 100 of the first embodiment is unnecessary, and the present invention can be applied even if the configuration is simpler than that of the hot water supply device 100. The purpose can be fulfilled.

  Also in the present embodiment, when the first boiling temperature T1 calculated according to the required amount of heat is equal to or lower than the first predetermined temperature Tst1, the first boiling temperature T1 is determined as the calculated temperature. In order to determine the second boiling temperature T2 as the low second predetermined temperature Tst2, high temperature hot water corresponding to the required amount of heat is stored in the upper part of the tank 10 and low temperature is stored in the lower part of the tank 10. Hot water kept at the boiling temperature can be stored. As a result, when the boiling operation is performed next time, the hot water temperature in the lower portion of the tank 10 can be lowered, and the reboiling of the remaining hot water that has been changed to medium temperature water can be suppressed, so that the efficiency (COP) of the heat pump unit 20 is reduced. Can be suppressed. Conversely, when the calculated first boiling temperature T1 is higher than the first predetermined temperature Tst1, the first boiling temperature T1 is determined to be the first predetermined temperature Tst1, and the second boiling temperature T2 is determined. Therefore, the temperature of the heat pump unit 20 is suppressed from being lowered by suppressing the temperature of boiling water to be stored in the upper part of the tank 10. Hot water at a temperature corresponding to the required amount of heat can be stored on the lower side.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the above embodiment, the operation results for a predetermined period (for example, one week) stored in the control device 40 are updated by updating predetermined operation information (model operation information) stored in advance at the time of factory shipment of the device. It may be adapted to the actual usage of the user.

  Further, the working refrigerant flowing through the heat pump cycle 20A of the heat pump unit 20 is not limited to carbon dioxide, but may be other refrigerants such as Freon.

10 ... tank 10c ... intermediate pipe (intermediate part inflow means)
10c1 ... intermediate part of tank 20 ... heat pump unit (heat pump type heating device)
21. Circuit (upper inflow means, intermediate inflow means)
22 ... Heat pump outlet three-way valve (upper inflow means, intermediate inflow means)
23 ... Branch piping (intermediate part inflow means)
24 ... Water supply pump (upper inflow means, intermediate inflow means)
40 ... Control device 72, 73 ... Reheating heat exchanger (heat exchange device)
74 ... Circuit 74a ... Tank outlet T1 ... First boiling temperature T2 ... Second boiling temperature Tst1 ... First predetermined temperature Tst2 ... Second predetermined temperature

Claims (6)

A tank (10) for storing hot water used for hot water supply;
A heat pump type heating device (20) for heating the hot water supply water taken out from the lower side of the tank;
A heat exchange device (72) for heating the external fluid by exchanging heat between the hot water supply water in the tank and a predetermined external fluid;
Upper inflow means (21, 22, 24) for causing hot water boiled to the first boiling temperature by the heat pump type heating device to flow into the tank from the upper part of the tank;
Below the portion where the hot water heated to the second boiling temperature lower than the first boiling temperature by the heat pump heating device is stored in the tank for exchanging heat with the external fluid. Intermediate part inflow means (21, 22, 23, 24, 10c) for inflowing into the tank from the intermediate part (10c1) of the tank set at the site;
The first boiling temperature and the second boiling temperature are determined, and the operation of the heat pump type heating device (20) is controlled so as to satisfy the determined temperature, and the upper inflow means and the intermediate portion inflow are controlled. A control device (40) for controlling the operation of the means,
When the controller (40) performs the boiling operation by the heat pump heating device,
The first boiling temperature is calculated according to the required amount of heat to be stored in the tank, and when the calculated first boiling temperature is equal to or lower than a first predetermined temperature (Tst1) set in advance, The boiling temperature is determined to be the calculated temperature, and the second boiling temperature is determined to be a second predetermined temperature (Tst2) that is lower than the first predetermined temperature (Tst1).
When the calculated first boiling temperature is higher than the first predetermined temperature (Tst1), the first boiling temperature is determined to be the first predetermined temperature (Tst1) and the second boiling temperature is determined. A hot water supply apparatus, wherein a raised temperature is determined to be a temperature calculated according to the necessary heat quantity.   The hot water supply apparatus according to claim 1, wherein the second predetermined temperature (Tst2) is a minimum boiling temperature determined in advance according to specifications of the hot water supply apparatus.   The hot water supply apparatus according to claim 1 or 2, wherein the first predetermined temperature (Tst1) is a maximum boiling temperature determined in advance according to specifications of the hot water supply apparatus. The heat exchange device (72) is arranged inside the tank (10),
The intermediate portion (10c1) of the tank is disposed at a position below the position where the heat exchange device (72) is disposed. Hot water supply device. The heat exchange device (73) is disposed outside the tank (10), and includes a circuit (74) that communicates the heat exchange device with the inside of the tank,
The intermediate part (10c1) of the tank is arranged at a position below the tank outflow part (74a) of the circuit where the hot water supply water in the tank is directed to the heat exchange device. The hot water supply device according to any one of claims 3 to 4. A tank (10) for storing hot water used for hot water supply;
A heat pump type heating device (20) for heating the hot water supply water taken out from the lower side of the tank;
A heat exchanging device (72) disposed in the tank and heating the external fluid by exchanging heat between the hot water supply water in the tank and a predetermined external fluid;
Upper inflow means (21, 24) for allowing hot water boiled by the heat pump type heating device to flow into the tank from the upper part of the tank;
A control device that determines the first boiling temperature and the second boiling temperature lower than the first boiling temperature, and controls the operation of the heat pump heating device (20) so as to satisfy the determined temperature. 40), and
When the controller (40) performs the boiling operation by the heat pump heating device,
The first boiling temperature is calculated according to the required amount of heat to be stored in the tank, and when the calculated first boiling temperature is equal to or lower than a first predetermined temperature (Tst1) set in advance, The boiling temperature is determined to be the calculated temperature, and the second boiling temperature is determined to be a second predetermined temperature (Tst2) that is lower than the first predetermined temperature (Tst1).
When the calculated first boiling temperature is higher than the first predetermined temperature (Tst1), the first boiling temperature is determined to be the first predetermined temperature (Tst1) and the second boiling temperature is determined. Determine the raised temperature to the temperature calculated according to the required heat amount,
After the hot water boiled to the determined second boiling temperature is flowed into the tank by the upper inflow means (21, 24), the hot water boiled to the determined first boiling temperature is stored in the tank. The hot water supply device is characterized in that the operation of the heat pump heating device (20) is controlled so as to flow into the water.

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