JP3915799B2 - Heat pump type water heater - Google Patents

Description

  The present invention relates to a heat pump hot water supply apparatus that heats water by a heat pump cycle.

  Conventionally, in this type of heat pump type hot water supply apparatus, a structure in which a hot water storage tank and a heat pump cycle are integrated has been proposed (for example, see Patent Document 1).

  FIG. 3 shows a conventional heat pump hot water supply apparatus described in Patent Document 1. As shown in FIG. In FIG. 3, 1 is a hot water storage tank. The compressor 2, the radiator 3, the pressure reducing means (not shown), and the heat absorber 4 form a heat pump cycle. Reference numeral 5 denotes air blowing means for supplying air to the heat absorber. 6 is a water injection pipe and 7 is a water discharge pipe.

The heat absorber 4 absorbs heat from the air supplied by the blower 5, and the water in the hot water storage tank 1 is heated by the heat radiation from the radiator 3. The compressor 2, the heat absorber 4, and the air blowing means 5 are arranged in the upper part of the hot water storage tank 1 to reduce the size of the apparatus.
JP-A-7-98156

  However, the conventional heat pump type hot water supply apparatus does not disclose the treatment of drain water generated by the evaporator.

  In order to solve the above-described conventional problems, the heat pump type hot water supply apparatus of the present invention is configured to discharge the expanded water from the pressure relief valve of the hot water storage tank to the drain water receiver that receives the drain water generated by the evaporator. is there.

  The heat pump hot water supply apparatus of the present invention can prevent the drain water receiver from freezing, reliably drain the drain water from the drain water receiver, and prevent other parts from getting wet due to the drain water overflow.

A first invention includes a heat pump cycle in which a compressor, a hot water supply heat exchanger, an expansion valve, and an evaporator are connected by refrigerant piping, a hot water storage tank for storing water heated by the hot water supply heat exchanger, and the hot water storage tank A pressure relief valve, an expansion water discharge means for discharging expansion water from the pressure relief valve, and a drain water receiver for receiving drain water generated by the evaporator, and the drain water receiver through the expansion water discharge means. By discharging the drain water, the drain water receiver can be prevented from freezing, the drain water can be drained normally from the drain water receiver, and other parts can be prevented from being wet due to the drain water overflow.

  In the second invention, in particular, in the first invention, the expanded water is discharged toward the drain water discharge port of the drain water receiver. And since high temperature expansion | swelling water is discharged | emitted toward a drain discharge port, freezing of a drain discharge port can be prevented.

  In the third invention, in particular, in any one of the first and second inventions, the expansion water discharge means is fixed so that the end of the expansion water discharge means connected to the pressure relief valve does not move. And since the terminal of an expansion water discharge means does not move, it can drain reliably to a drain water receptacle.

  According to a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, a drain water receiver is provided immediately above the hot water heat exchanger. And the heat radiation of the heat exchanger for hot water supply is received by the drain water receiver, and the drain water receiver can be more reliably prevented from freezing.

  In a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the drain water receiver and the refrigerant pipe before the expansion valve are brought into contact with each other. Then, heat is radiated from the refrigerant in the refrigerant pipe before the expansion valve to the drain water receiver, so that the drain water receiver can be more reliably prevented from freezing. Further, the degree of supercooling of the refrigerant can be increased, and COP can be improved.

  In a sixth aspect of the present invention, in particular, in any one of the first to fifth aspects of the present invention, water discharge detection means for detecting water discharge from a hot water supply terminal such as a faucet, and control for controlling the compressor in response to a signal from the water discharge detection means And the control means activates the compressor when water discharge is detected by a signal from the water discharge detection means. And since water discharge is detected from a hot water supply terminal and a compressor is started, the hot water heated with the heat exchanger for hot water supply can be directly discharged from a hot water supply terminal.

  In a seventh aspect of the invention, in particular, in any one of the first to sixth aspects of the invention, the outlet is detected from a hot water supply terminal such as a faucet, and the compressor is controlled in response to a signal from the outlet detection means. Control means, and the control means controls to increase the rotational speed of the compressor as the detected flow rate of the water discharge detection means increases. And the hot water of preset temperature can be poured out in the wide discharge flow rate.

  In an eighth aspect of the invention, in particular, in any one of the first to seventh aspects, a first mixing means for mixing hot water from a hot water supply heat exchanger and hot water from a hot water storage tank is provided. And the lack of the heating capability at the time of heat pump driving | running | working start can be compensated, the hot-water temperature rise after water discharge from a hot-water supply terminal can be accelerated | stimulated, and the time until it can discharge at a preset temperature can be shortened more. Further, when the heating capacity is insufficient even in the steady state, the shortage can be compensated.

  In the ninth aspect of the invention, in particular, in the eighth aspect of the invention, the second mixing means for mixing the hot water from the first mixing means and the cold water from the water pipe is provided. And when the hot water temperature discharged from a 1st mixing means is higher than preset temperature, water can be mixed and it can be made preset temperature.

In a tenth aspect of the invention, in particular, in any one of the first to ninth aspects of the invention, the refrigerant used for the heat pump cycle is carbon dioxide, and the high pressure side is operated in a state exceeding the critical pressure. And hot water can be produced | generated and since hot water can be stored, a hot water storage tank can be reduced in size.

  In an eleventh aspect of the invention, in particular, in any one of the first to tenth aspects of the invention, the heat pump cycle and the hot water storage tank are housed in the same casing. And since an apparatus can be reduced in size, the freedom degree of installation can be expanded. Moreover, since the distance between the evaporator and the hot water storage tank is reduced, these heat exchange relationships can be easily established.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a circuit configuration diagram according to the first embodiment of the present invention. FIG. 2 is an arrangement configuration diagram of a hot water heat exchanger and the like in the same embodiment.

  First, the refrigeration circuit of the heat pump hot water supply apparatus according to this embodiment will be described. In FIG. 1, it is preferable that the heat pump cycle 20 is operated in a state where carbon dioxide is used as a refrigerant and the high pressure side exceeds the critical pressure.

  The heat pump cycle 20 is configured by connecting a compressor 21, a hot water supply heat exchanger 22, a bath heat exchanger 26, an expansion valve 23, and an evaporator 24 in order by piping. The heat pump cycle 20 includes a bypass circuit 25 that bypasses the hot water supply heat exchanger 22, and the bypass circuit 25 is provided with a control valve 25 </ b> A. Further, the heat pump cycle 20 includes a temperature sensor 20A that detects the temperature of the compressor 21, a temperature sensor 20B that detects the refrigerant temperature discharged from the compressor 21, a pressure sensor 20C that detects the refrigerant pressure discharged from the compressor 21, A temperature sensor 20D for detecting the low-pressure refrigerant temperature on the outlet side of the evaporator 24, a temperature sensor 20E for detecting the intake air of the evaporator 24, and a temperature sensor 20F for detecting the inlet refrigerant temperature of the bath heat exchanger 26 are provided. .

  Here, the temperature sensor 20A detects a cold start, and the pressure sensor 20C detects an abnormality of the compressor 21 or the heat pump cycle 20. Further, a fan 27 and an air passage 28 for sending air to the evaporator 24 are provided. The evaporator 24 is a so-called fin tube type refrigerant-to-air heat exchanger.

  Next, the hot water circuit of the heat pump type hot water supply apparatus according to the present embodiment will be described. The inflow side of the water pipe 22 </ b> A of the hot water supply heat exchanger 22 is connected to a water supply pipe 34 such as a water pipe via a flow rate adjusting valve 31, a pressure reducing valve 32, and a check valve 33. On the other hand, the outflow side of the water pipe 22A is connected to a hot water supply faucet 38 (hot water supply terminal) such as a kitchen or a washroom through a check valve 35, a first mixing means 36, and a second mixing means 37. ing. The hot water supply circuit includes a flow rate sensor 30A (outflow detection means) that detects water flow from a hot water supply terminal such as the faucet 38 and the bathtub 60 and detects the flow rate thereof, a temperature sensor 30B that detects the incoming water temperature, and a water pipe 22A. The temperature sensor 30C for detecting the outlet temperature, the temperature sensor 30D for detecting the outlet temperature of the first mixing means 36, the temperature sensor 30E for detecting the outlet temperature of the second mixing means 37, and the inflow flow rate to the hot water supply heat exchanger 22 A flow sensor 30F for detection is provided.

Next, a hot water storage circuit of the heat pump hot water supply apparatus according to the present embodiment will be described. A bottom pipe 42 of the hot water storage tank 40 is connected to a water supply pipe 34 such as a water pipe via a flow rate adjusting valve 31, a pressure reducing valve 32, and a check valve 41. The bottom pipe 42 is connected to the inflow side of the water pipe 22 </ b> A via the circulation pump 43. The upper circulation pipe 4 of the hot water storage tank 40
4 is connected to the outflow side of the water pipe 22 </ b> A via the control valve 45. The hot water storage tank 40 according to the present embodiment is a stacked hot water tank, and is configured so that stirring in the tank is prevented and high temperature water is accumulated at the top and low temperature water is accumulated at the bottom.

  On the other hand, the upper hot water supply pipe 51 of the hot water storage tank 40 is connected to the first mixing means 36. Further, a water discharge pipe 52 branched from the bottom pipe 42 of the hot water storage tank 40 is connected to the second mixing means 37 via a check valve 53. The hot water storage tank 40 is provided with a plurality of temperature sensors 40B, 40C and 40D for detecting the amount of hot water in the hot water storage tank 40 in addition to the temperature sensor 40A for detecting the temperature of the hot water. In addition, a temperature sensor 40 </ b> E that detects the hot water temperature derived from the bottom pipe 42 of the hot water storage tank 40 is provided in the inflow side pipe before branching of the water pipe 22 </ b> A.

  Next, the bathtub heating circuit of the heat pump type hot water supply apparatus according to the present embodiment will be described. The water pipe 26 </ b> A of the bath heat exchanger 26 is connected to a bathtub circulation pipe 62 including a circulation pump 61. The bathtub circulation pipe 62 includes a bypass pipe 63 that bypasses the water pipe 26 </ b> A, and a three-way valve 64 that switches between the water pipe 26 </ b> A and the bypass pipe 63. Further, the bathtub circulation pipe 62 includes a flow sensor 60A for detecting the circulation amount of the bathtub water, a temperature sensor 60B for detecting the outlet temperature of the water pipe 26A, a temperature sensor 60C for detecting the circulation temperature of the bathtub water, A water level sensor 60D for detecting the water level is provided.

  In addition, the pouring to the bathtub 60 can be performed using the pouring pipe 71 branched from the downstream pipe of the second mixing means 37. The pouring pipe 71 is connected to the bathtub circulation pipe 62 or directly led to the bathtub 60. The pouring pipe 71 is provided with a pouring valve 72 and a flow rate sensor 70A for detecting the flow rate.

  The remote controller 81 instructs the hot water temperature from the faucet 38, the boiling temperature of the bathtub 60, the start of boiling, and the like. Based on the instructions from the remote controller 81, the first heat pump cycle 10 and the second heat pump cycle. 20 is controlled by the control means 82. The detection values of various sensors are input to this control means 82.

  Next, the drainage path of the heat pump type hot water supply apparatus according to this embodiment will be described. A drain water receiver 91 receives drain water generated from the evaporator 24. The expansion water discharged from the pressure relief valve 92 of the hot water storage tank 40 is discharged to the drain water receiver 91 through the expansion water discharge means 93. The end of the expansion water discharge means 93 is fixed to the drain water discharge port 95 by the fixing means 94 and is fixed in the vicinity of the drain water discharge port 95. The drain water receiver 91 and the refrigerant pipe 96 in front of the expansion valve 23 are in contact with each other by brazing.

  A tank drainage passage 98 is connected to the hot water storage tank 40 via a tank drain valve 97 for draining from the hot water storage tank 40 when the apparatus is moved or maintained. Further, the drain water drainage passage 99 is connected to the drain water discharge port 95. The above-described heat pump hot water supply apparatus is housed in the housing 100.

  Hereinafter, the operation of the heat pump hot water supply apparatus according to the present embodiment will be described. First, a normal hot water supply operation mode of the heat pump hot water supply apparatus according to the present embodiment will be described.

  The faucet 38 is opened, and water discharge is detected by the flow sensor 30A, and the heat pump cycle 20 starts operation.

The refrigerant compressed by the compressor 21 dissipates heat in the hot water supply heat exchanger 22, is decompressed by the expansion valve 23, absorbs heat in the evaporator 24, and is sucked into the compressor 21 in a gas state. At this time, the control valve 2
5A is in a closed state, and no refrigerant flows into the bypass circuit 25.

  Water supplied from the water supply pipe 34 passes through the flow rate adjustment valve 31, the pressure reducing valve 32, and the check valve 33 in order, and is led to the water pipe 22 </ b> A of the hot water supply heat exchanger 22. The hot water heated by the water pipe 22 </ b> A passes through the check valve 35, the first mixing unit 36, and the second mixing unit 37 in order and is guided to the faucet 38.

  In the capacity control in the compressor 21 and the opening degree control in the expansion valve 23, the temperature sensors 20B, 20D and 20E and the flow rate sensor 30A are set so that the temperature detected by the temperature sensor 30C approaches the hot water temperature set by the remote controller 81. , Controlled by the detected value from 30H. Here, the rotation speed of the compressor 21 is controlled to increase as the detected flow rate of the flow rate sensor 30A increases.

  Even if the capacity control in the heat pump cycle 20 is performed, if the water temperature from the hot water supply heat exchanger 22 is higher than the set temperature, cold water is introduced into the second mixing means 37 from the outlet pipe 52, Control is performed so that the outlet temperature at the two mixing means 37 becomes the set temperature.

  Further, even when the capacity control in the heat pump cycle 20 is performed, if the water temperature from the hot water supply heat exchanger 22 is lower than the set temperature, hot water is introduced from the hot water storage tank 40 to the first mixing means 36, and the first Control is performed so that the outlet temperature at the mixing means 36 becomes the set temperature. Further, when the outlet temperature at the first mixing means 36 is lower than the set temperature, the first mixing means 36 reduces the opening amount of the flow regulating valve 31 in the normally fully opened state to reduce the hot water flow rate from the faucet 38. The outlet temperature is controlled to be the set temperature.

  Next, start-up control in the hot water supply operation mode of the heat pump hot water supply apparatus according to the present embodiment will be described. A sufficient amount of heat radiation cannot be obtained by the hot water supply heat exchanger 22 for a predetermined time from the start of the compressor 21. Accordingly, the opening of the faucet 38 is detected by the flow rate sensor 30 </ b> A, and the heat pump cycle 20 starts operation, and at the same time, the hot water in the hot water storage tank 40 is guided from the upper hot water supply pipe 51 to the first mixing means 36. At this time, the temperature of the temperature sensor 30E and the temperature sensor 40A is detected, and the mixing ratio in the first mixing means 36 is controlled so that the temperature detected by the temperature sensor 30D becomes the set temperature. At the start of operation, since the water temperature from the hot water supply heat exchanger 22 is low, a large amount of hot water flows from the hot water supply tank 40, and then the hot water from the hot water supply tank 40 decreases as the water temperature from the hot water supply heat exchanger 22 increases. . And the hot water supply from the hot water supply tank 40 is stopped when the water temperature from the hot water supply heat exchanger 22 is sufficiently increased.

  Next, the hot water storage operation mode of the heat pump hot water supply apparatus according to the present embodiment will be described. In the hot water storage operation mode, the control valve 45 is opened and the circulation pump 43 is operated. By operating the circulation pump 43, cold water is led out from the bottom pipe 42 of the hot water storage tank 40 and led to the water pipe 22 </ b> A of the hot water supply heat exchanger 22. The hot water heated by the hot water supply heat exchanger 22 is returned to the upper part of the hot water storage tank 40 from the upper circulation pipe 44. The capacity control in the compressor 21 includes the inlet temperature of the hot water heat exchanger 22 by the temperature sensor 40E, the outlet temperature of the hot water heat exchanger 22 by the temperature sensor 30E, the circulating flow rate by the flow sensor 30F, the temperature sensor 20B, Controlled by 20D and 20E. The amount of hot water stored in the hot water storage tank 40 is detected by the temperature sensors 40B, 40C, 40D. When the amount of hot water stored in the hot water storage tank 40 is detected to be below a predetermined value, the hot water storage operation is started. When it is detected that the temperature exceeds the predetermined value, the hot water storage operation is stopped.

  Next, the bathtub heating operation mode of the heat pump hot water supply apparatus according to the present embodiment will be described. In the bathtub heating operation mode, the control valve 25A is opened. The refrigerant compressed by the compressor 21 flows through the bypass circuit 25, dissipates heat in the bath heat exchanger 26, is decompressed by the expansion valve 23, absorbs heat in the evaporator 24, and enters the compressor 21 in a gas state. Inhaled.

  On the other hand, the circulation pump 61 is operated, the bathtub water in the bathtub 60 is guided to the water pipe 26A through the bathtub circulation pipe 62, and the bathtub water heated by the water pipe 26A is returned into the bathtub 60.

  In the capacity control in the compressor 21 and the opening degree control in the expansion valve 23, the temperature sensors 20F, 60B, 60C, 20B, and 20D are set so that the temperature detected by the temperature sensor 60C approaches the hot water temperature set by the remote controller 81. , 20E and 20F. The circulation amount in the circulation pump 61 is controlled by the flow sensor 60A. In order to detect the temperature in the bathtub 60, the bath heat exchanger 26 is bypassed by switching the three-way valve 64, and the bathtub water is circulated by the circulation pump 61, the bypass pipe 63, and the bathtub 60, and the temperature sensor 60C is used. To detect.

  On the other hand, when hot water is added to the bathtub 60 or when the bathtub 60 is filled with water from an empty state, the hot water supply valve 72 is opened and controlled in the same manner as in the hot water supply operation mode, and the hot water supply pipe 71 is used for the bathtub. Hot water is supplied to the bathtub 60 via the circulation pipe 62.

  Next, the defrosting operation mode of the heat pump type hot water supply apparatus according to the present embodiment will be described. The control valve 25A is opened, the expansion valve 23 is fully opened, and the operation of the fan 27 is stopped. The refrigerant compressed by the compressor 21 flows through the bypass circuit 25, dissipates heat in the evaporator 24, and is sucked into the compressor 21 in a gas state. In this way, the evaporator 24 can be defrosted. In addition, detection of frost formation is performed by the temperature sensors 20D and 20E.

  As described above, each mode of the heat pump hot water supply apparatus has been described. When hot water is stored in the hot water storage tank 40, the hot water is drained from the pressure relief valve 92 regardless of the operation mode, and the water pressure of the hot water storage tank 40 is predetermined. Prevents pressure over pressure. This high-temperature expansion water is discharged to the drain water receiver 91 by the expansion water discharge means 93.

  As described above, by discharging the high-temperature expansion water to the drain water receiver 91, the drain water receiver 91 can be prevented from freezing, and the drain water can be drained normally from the drain water receiver 91, and the drain water overflows. Can prevent other parts from getting wet.

  Further, the expanded water is discharged toward the drain water discharge port 95 of the drain water receiver 91. And since the high temperature expansion | swelling water is discharged | emitted toward the drain discharge port 95, freezing of the drain discharge port 95 can be prevented.

  The expansion water discharge means 93 is fixed by the fixing means 94 so that the end of the expansion water discharge means 93 connected to the pressure relief valve 92 does not move. And since the terminal of the expansion water discharge means 93 does not move, it can drain into the drain water receptacle 91 reliably.

  Further, a drain water receiver 91 is provided immediately above the hot water heat exchanger 22. And the heat radiation of the hot water supply heat exchanger 22 is received by the drain water receiver 91, and the drain water receiver 91 can be more reliably prevented from freezing.

  Moreover, the drain water receptacle 91 and the refrigerant | coolant piping before an expansion valve are made to contact. Heat is radiated from the refrigerant in the refrigerant pipe 96 before the expansion valve to the drain water receiver 91, so that the drain water receiver 91 can be more reliably prevented from freezing. Further, the degree of supercooling of the refrigerant can be increased, and COP can be improved.

  Further, when water discharge is detected by the signal from the flow sensor 30A, the compressor 21 is started. And since water discharge is detected from a hot water supply terminal and the compressor 21 is started, the hot water heated with the heat exchanger 22 for hot water supply can be directly discharged from a hot water supply terminal.

  Moreover, it controls so that the rotation speed of the compressor 21 becomes large, so that the detection flow volume of 30 A of flow sensors is large. And the hot water of preset temperature can be poured out in the wide discharge flow rate.

  A first mixing means 36 for mixing hot water from the hot water supply heat exchanger 22 and hot water from the hot water storage tank 40 is provided.

  And the lack of the heating capability at the time of heat pump driving | running | working start can be compensated, the hot-water temperature rise after water discharge from a hot-water supply terminal can be accelerated | stimulated, and the time until it can discharge at a preset temperature can be shortened more. Further, when the heating capacity is insufficient even in the steady state, the shortage can be compensated.

  Moreover, the 2nd mixing means 37 which mixes the warm water from the 1st mixing means 36 and the cold water from a water pipe is provided. And when the hot water temperature discharged from the 1st mixing means 36 is higher than preset temperature, water can be mixed and it can be made preset temperature.

  Moreover, the refrigerant | coolant used for the heat pump cycle 20 is carbon dioxide, and it drive | operates in the state exceeding a critical pressure on the high voltage | pressure side. And hot water can be produced | generated and since hot water can be stored, a hot water storage tank can be reduced in size.

  Further, the heat pump cycle 20 and the hot water storage tank 40 are accommodated in the same casing 111. And since an apparatus can be reduced in size, the freedom degree of installation can be expanded. Further, the heat exchange relationship between the hot water storage tank 40 and the evaporator 24 can be easily constructed.

  In the above embodiment, carbon dioxide is used as the refrigerant. However, other refrigerants such as 410A refrigerant and HC refrigerant may be used as the refrigerant.

  Moreover, although the said embodiment demonstrated using the heat pump type hot water supply apparatus provided with the single heat pump cycle 20, you may use two or more heat pump cycles.

  Moreover, in the said embodiment, in order to maximize the thermal radiation amount in the heat exchanger 26 for baths, it is still more preferable to provide the control valve which prevents the refrigerant | coolant inflow to the heat exchanger 22 for hot water supply.

  In the above embodiment, the hot water heated by the hot water supply heat exchanger 22 is returned to the upper part of the hot water storage tank 40 from the upper circulation pipe 44. However, the upper circulation pipe 44 and the control valve 45 are provided. Without using the first mixing means 36, the outlet side pipes of the hot water supply heat exchanger 12 and the hot water supply heat exchanger 22 and the upper hot water supply pipe 51 are communicated with each other so that they are heated by the hot water supply heat exchanger 22. The warm water may be returned to the upper part of the hot water storage tank 40.

  The bath heat exchanger 26 in the above description can also be used as a heat exchanger for heating such as floor heating or hot air equipment.

  In addition, the heat pump cycle 20 and the hot water storage tank 40 have been described as being housed in the same housing 111, but each is housed in a separate housing or installed separately, or in a separate housing at the time of factory shipment. They can be stored and shipped, and these cases can be assembled and integrated at the installation site.

As described above, the heat pump hot water supply apparatus according to the present invention can be applied to a heat pump hot water supply apparatus that heats water by a heat pump cycle, and has industrial applicability.

The circuit block diagram of the heat pump type hot-water supply apparatus in Embodiment 1 of this invention Arrangement configuration diagram of heat exchanger and the like for hot water supply in Embodiment 1 Overall configuration diagram of a conventional heat pump type hot water supply device

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Heat pump cycle 21 Compressor 22 Heat exchanger for hot water supply 23 Expansion valve 24 Evaporator 30A Flow rate sensor (outflow detection means)
36 First mixing means 37 Second mixing means 38 Faucet (hot water supply terminal)
40 Hot Water Storage Tank 82 Control Unit 91 Drain Water Receiving 92 Pressure Relief Valve 93 Expansion Water Discharge Unit 94 Fixing Unit 94
95 Drain water outlet 96 Refrigerant piping before expansion valve 100 Housing

Claims (11)

A heat pump cycle in which a compressor, a hot water heat exchanger, an expansion valve, and an evaporator are connected by refrigerant piping; a hot water storage tank that stores water heated by the hot water heat exchanger; and a pressure relief valve of the hot water tank; An expansion water discharge unit that discharges the expansion water that exits from the pressure relief valve and a drain water receiver that receives the drain water generated by the evaporator are configured to be discharged to the drain water receiver through the expansion water discharge unit . Heat pump water heater. The heat pump type hot water supply apparatus according to claim 1, wherein the expanded water is discharged toward a drain water discharge port of the drain water receiver. The heat pump type hot water supply apparatus according to claim 1 or 2, further comprising a fixing means for fixing the expansion water discharge means so that the end of the expansion water discharge means connected to the pressure relief valve does not move. The heat pump type hot water supply apparatus according to any one of claims 1 to 3, wherein a drain water receiver is provided immediately above the hot water supply heat exchanger. The heat pump type hot water supply apparatus according to any one of claims 1 to 4, wherein the drain water receiver and the refrigerant pipe before the expansion valve are brought into contact with each other. A water discharge detection means for detecting water discharge from a hot water supply terminal such as a faucet, and a control means for controlling a compressor in response to a signal from the water discharge detection means, wherein the control means detects water discharge by a signal from the water discharge detection means. Then, the heat pump type hot water supply apparatus according to any one of claims 1 to 5, wherein the compressor is started. A water discharge detection means for detecting water discharge from a hot water supply terminal such as a faucet; and a control means for controlling the compressor in response to a signal from the water discharge detection means, wherein the control means has a flow rate detected by the water discharge detection means. The heat pump type hot water supply apparatus according to any one of claims 1 to 6, which is controlled so as to increase the rotational speed of the compressor as the value increases. The heat pump type hot water supply apparatus according to any one of claims 1 to 7, further comprising first mixing means for mixing hot water from a hot water supply heat exchanger and hot water from a hot water storage tank. The heat pump type hot water supply apparatus according to claim 8, further comprising second mixing means for mixing hot water from the first mixing means and cold water from the water pipe. The heat pump type hot water supply apparatus according to any one of claims 1 to 9, wherein the refrigerant used in the heat pump cycle is carbon dioxide, and the high pressure side is operated in a state exceeding a critical pressure. The heat pump type hot water supply apparatus according to any one of claims 1 to 10, wherein the heat pump cycle and the hot water storage tank are housed in the same casing.

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