JP2011153790A - Heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type water heater capable of performing boiling operation temporarily even when a temperature sensor itself for detecting a temperature of hot water after heat exchange by a water refrigerant heat exchanger is broken. <P>SOLUTION: The heat pump type water heater includes: a control means 26 performing boiling operation so that a detection temperature by a boiling temperature detection means 25 becomes a boiling target temperature; a failure determination means 27 determining whether or not the boiling temperature detection means 25 itself is broken; and an operating state storage means 28 storing a value of each of rotational frequency of a compressor 14, rotational frequency of a circulating pump 20 and a refrigerant discharge temperature when the boiling operation is stabilized during the boiling operation. In the case where the boiling operation is performed after the failure determination means 27 determines that the boiling temperature detection means 25 itself is broken, the control means 26 performs alternative boiling operation for boiling hot water within a hot water storage tank 2 based on the values stored in the operating state storage means 28, so as to perform boiling operation temporarily. Thus, a situation where the hot water storage tank 2 has no water can be avoided. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat pump type water heater.

  Conventionally, in this type of heat pump type hot water heater, the hot refrigerant discharged from the compressor and the hot water from the hot water storage tank are heat-exchanged by a water refrigerant heat exchanger, and the hot water in the hot water storage tank is heated up. The boiling operation is controlled so that the temperature of the hot water detected by the temperature sensor provided at the outlet of the water-refrigerant heat exchanger becomes the set boiling target temperature. (For example, refer to Patent Document 1).

  Moreover, in the heat pump type hot water heater as disclosed in Patent Document 1, generally, the temperature of hot water detected by the temperature sensor at the outlet of the water-refrigerant heat exchanger exceeds the preset temperature range and is abnormally high. When an abnormal temperature such as the above is detected, an error is notified and the boiling operation is stopped.

JP 2009-250465 A

  By the way, when detecting abnormal temperature such that the temperature of hot water detected by the temperature sensor rises stepwise during boiling operation and becomes abnormally high, it is necessary to stop boiling operation, If the temperature sensor detects an abnormal temperature when the boiling operation is stopped or the boiling operation is started, the temperature sensor itself is suspected of being broken or short-circuited.In this case, the compressor, expansion valve, etc. Since there is no abnormality in the functional parts, the hot water in the hot water storage tank cannot be boiled even though the boiling operation can be performed. In particular, if the temperature sensor itself fails before the midnight time boiling operation is performed at night, the boiling operation will not be performed even in the midnight time zone. However, there is almost no hot water, which causes the user to feel inconvenient.

  In view of the above, the present invention provides an emergency heating operation even when there is a failure in the temperature sensor itself that detects the temperature of hot water at the outlet of the water-refrigerant heat exchanger before the boiling operation is started. It is an object of the present invention to provide a heat pump type water heater that can avoid a situation where there is almost no hot water in a tank.

  In order to solve the above-described problems, the present invention provides a heat pump unit having a heat pump circuit in which a compressor, a water refrigerant heat exchanger, an expansion valve, and an air heat exchanger are connected in a ring shape with refrigerant piping, and hot water. A hot water storage tank for storing hot water, a circulation circuit in which the hot water storage tank and the water side of the water-refrigerant heat exchanger are annularly connected by hot water piping, a circulation pump provided in the middle of the circulation circuit, and the compressor discharged from the compressor Discharge temperature detection means for detecting the discharge temperature of the refrigerant, boiling temperature detection means for detecting the boiling temperature of hot water after heat exchange with the water refrigerant heat exchanger, and the detected temperature of the boiling temperature detection means Heat pump type hot water supply comprising control means for controlling the heat pump unit and the circulation pump so as to reach a boiling target temperature to perform a boiling operation for boiling hot water in the hot water storage tank A failure determination means for determining whether or not the boiling temperature detection means itself is a failure based on a temperature detected by the boiling temperature detection means, and the compressor when the boiling operation is stable during the boiling operation. Operating state storage means for storing values of the rotational speed of the circulation pump, the rotational speed of the circulation pump, and the discharge temperature, and the failure determination means determines that the boiling temperature detection means itself has failed. When the boiling operation is performed later, the control means performs an alternative boiling operation for boiling hot water in the hot water storage tank based on a value stored in the operation state storage means.

  According to a second aspect of the present invention, the control unit controls the compressor using the rotation speed of the compressor stored in the operation state storage unit as a target value, and the circulation pump stored in the operation state storage unit The circulation pump is controlled with the rotational speed of the engine as a target value, and the opening of the expansion valve is adjusted so that the discharge temperature of the refrigerant detected by the discharge temperature detection means becomes the discharge temperature stored in the operation state storage means. The above-mentioned alternative boiling operation is performed by controlling.

  According to a third aspect of the present invention, in the heat pump type water heater according to the second aspect, a refrigerant outlet temperature detecting means for detecting an outlet temperature of the refrigerant after heat exchange with the water refrigerant heat exchanger is provided, and the operation state storage means Stores the value of the outlet temperature when the boiling operation is stable, and the control means stores the refrigerant outlet temperature detected by the refrigerant outlet temperature detection means in the operation state storage means when the alternative boiling operation is stable. The number of rotations of the circulating pump rotating at the target value is controlled to increase or decrease so as to have the stored outlet temperature.

  Moreover, in Claim 4, in the heat pump type hot water heater according to any one of Claims 1 to 3, an outside air temperature detecting means for detecting an outside air temperature, and hot water before heat exchange with the water-refrigerant heat exchanger. Incoming water temperature detecting means for detecting the incoming water temperature, and the operation state storage means stores the values of the outside air temperature and the incoming water temperature when the boiling operation is stable during the boiling operation, the control means, The value stored in the operation state storage means is the outside air temperature detected by the outside air temperature detecting means or the incoming water temperature detected by the incoming water temperature detecting means when the alternative boiling operation is started or during the alternative boiling operation. When the temperature is higher than the predetermined temperature, the alternative boiling operation is stopped.

  According to the first aspect of the present invention, when it is determined that the boiling temperature detecting means itself has failed, it is stored in the operation state storage means when the boiling operation is stable before the boiling temperature detecting means fails. By performing an alternative boiling operation based on the value, it is possible to perform an emergency boiling operation, avoiding the situation where there is almost no hot water in the hot water storage tank, and making the user feel inconvenient There is nothing.

  Further, according to claim 2, when it is determined that the boiling temperature detecting means itself has failed, the control means follows the movement at the time of stable heating operation before the boiling temperature detecting means fails, By performing the alternative boiling operation by controlling the compressor, expansion valve and circulation pump, the boiling operation can be performed quickly and smoothly, and the situation where there is almost no hot water in the hot water storage tank can be avoided. This does not cause the user to feel inconvenient.

  According to claim 3, when the alternative boiling operation is stable, the refrigerant rotates at the target value so that the outlet temperature of the refrigerant detected by the refrigerant outlet temperature detecting means becomes the outlet temperature stored in the operation state storage means. By increasing / decreasing the number of rotations of the circulation pump, the boiling operation can be smoothly performed more closely to the movement at the time of stable heating operation before the boiling temperature detecting means fails.

  According to the fourth aspect, the alternative boiling operation is performed only when the boiling operation is stable, which is stored in the operation state storage means, and the alternative boiling operation is stopped when leaving the state. Thus, the boiling operation can be finished in a safe state before a failure such as abnormality or failure occurs in the appliance.

The schematic block diagram of one Embodiment of this invention. The principal part block diagram of the same embodiment. The flowchart for demonstrating operation | movement of the same embodiment.

  Next, a heat pump type water heater according to an embodiment of the present invention will be described with reference to the drawings.

  1 is a hot water storage tank unit that contains a hot water storage tank 2 for storing hot water, 3 is a heat pump unit that heats the hot water in the hot water storage tank 2, and 4 is a forward pipe 5 connected to the lower part of the hot water storage tank 2 and an upper part of the hot water storage tank 2. A circulation circuit composed of a return pipe 6 connected to the hot water tank 7 is connected to the lower part of the hot water tank 2 to supply water to the hot water tank 2, and 8 is connected to the upper part of the hot water tank 2 to store hot water stored in the hot water. It is a tapping pipe that drains water.

  9 is a water supply bypass pipe branched from the water supply pipe 7, 10 is a mixing valve for mixing hot water from the hot water outlet pipe 8 and water from the water supply bypass pipe 9 to make hot water at a hot water supply set temperature, and 11 is a mixing valve 10. A plurality of hot water temperature sensors 12 for detecting the hot water temperature after mixing, a plurality of hot water temperature sensors 12 for detecting the temperature of hot water in the hot water tank 2 are provided across the upper and lower sides of the hot water tank 2, and 13 are sensors in the hot water tank unit 1. Is a hot water storage control means for controlling the operation of each actuator.

  The hot water storage control means 13 predicts the hot water supply amount for the next day from the actual use of hot water such as the maximum value and the average value of the hot water supply for the past several days, and sets the boiling target temperature to 65 so that the predicted hot water supply amount can be secured. The heat pump unit 3 is determined in the range from 0 ° C. to 90 ° C., and the hot water in the hot water storage tank 2 reaches a predetermined boiling target temperature when the unit price of the contracted electric power by time zone is an inexpensive midnight time zone. A heating operation start command for boiling is given to the heat pump unit 3 side.

  The heat pump unit 3 includes a variable speed compressor 14 that compresses the refrigerant, a water refrigerant heat exchanger 15 that exchanges heat between the high-temperature and high-pressure refrigerant and the hot water in the hot water storage tank 2, and the water refrigerant heat exchanger 15. A heat pump circuit 18 in which an expansion valve 16 as a pressure reducer for reducing the pressure of the later refrigerant and an air heat exchanger 17 as an evaporator for evaporating the low-temperature and low-pressure refrigerant from the expansion valve 16 are connected in an annular shape by refrigerant piping; The outdoor fan 19 that blows air to the air heat exchanger 17, the water side of the water-refrigerant heat exchanger 15, and the hot water storage tank 2 are provided in the circulation circuit 4 that is annularly connected by hot water piping, and the hot water in the hot water storage tank 2 is circulated. And a circulation pump 20 having a variable rotation speed.

  A discharge temperature sensor 21 is provided in a refrigerant pipe between the compressor 14 and the water refrigerant heat exchanger 15 and detects discharge temperature of the refrigerant discharged from the compressor 14, and 22 is a water refrigerant. A refrigerant outlet temperature sensor provided as a refrigerant outlet temperature detecting means provided on a refrigerant pipe between the heat exchanger 15 and the expansion valve 16 and detecting a refrigerant outlet temperature after heat exchange in the water refrigerant heat exchanger 15; Is provided on the air inlet side of the air heat exchanger 17 and is an outside air temperature sensor as an outside air temperature detecting means for detecting outside air temperature, and 24 flows into the water side of the water refrigerant heat exchanger 15, and the water refrigerant heat exchanger 15 An incoming water temperature sensor 25 serving as an incoming water temperature detecting means for detecting the incoming water temperature of the hot water before heat exchange at the water outlet flows out from the water side of the water refrigerant heat exchanger 15 and heat exchange is performed in the water refrigerant heat exchanger 15. Detect the boiling temperature of hot water A boiling temperature sensor as boiling temperature detecting means.

  Reference numeral 26 denotes a heating control means as a control means for receiving the output of each sensor in the heat pump unit 3 and controlling the operation of each actuator. The heating control means 26 is communicably connected to the hot water storage control means 13 and operates in cooperation with the hot water storage control means 13. To do.

  The heating control means 26 determines whether or not the boiling temperature sensor 25 itself has failed based on the temperature detected by the boiling temperature sensor 25 when the boiling operation is stopped during the midnight hours or when the boiling operation is started. When the determination is made and the boiling temperature sensor 25 itself is determined to be in failure, the failure determination means 27 for notifying the error and not prohibiting the heating operation, and the boiling operation during the midnight time zone, The rotation speed of the compressor 14 when the boiling operation is stable, that is, after the elapse of a predetermined time from the start of the boiling operation or when the boiling temperature detected by the boiling temperature sensor 25 reaches the boiling target temperature, The number of revolutions, the discharge temperature detected by the discharge temperature sensor 21, the outlet temperature detected by the refrigerant outlet temperature sensor 22, the outside air temperature detected by the outside air temperature sensor 23, and the incoming water temperature sensor 24 is provided with an operation state storage means 28 for storing each value of the incoming water temperature detected by the operation state storage means 28. The operation state storage means 28 is provided for each boiling operation at midnight time when the boiling operation is stable. Each of the above values is updated.

Next, the normal boiling operation in the midnight time zone of the present embodiment, that is, the operation of the boiling operation in a state where the boiling temperature sensor 25 itself is not broken will be described.
In the midnight time zone when the power unit price is cheap, the hot water storage control means 13 starts the boiling operation to heat up the hot water in the hot water storage tank 2 at the predetermined boiling target temperature by the heating control means 26. To instruct. The heating control means 26 controls the compressor 14 at the number of revolutions corresponding to the outside air temperature detected by the outside air temperature sensor 23, sets the target discharge temperature according to the boiling target temperature, and detects it by the discharge temperature sensor 21. The opening degree of the expansion valve 16 is controlled so that the discharge temperature of the refrigerant to be reached becomes the target discharge temperature. In addition, the outdoor fan 19 is also controlled at a preset rotational speed corresponding to the outside air temperature detected by the outside air temperature sensor 23. At the same time, the heating control means 26 controls the number of revolutions of the circulation pump 20 so that the temperature of the hot water heated by the water refrigerant heat exchanger 15 detected by the boiling temperature sensor 25 becomes the boiling target temperature. The heating control means 26 performs a boiling operation.

  When the boiling operation is stabilized after a predetermined time has elapsed from the start of the boiling operation, the operation state storage unit 28 is configured to store the rotation speed of the compressor 14, the rotation speed of the circulation pump 20, the discharge temperature detected by the discharge temperature sensor 21, The outlet temperature detected by the refrigerant outlet temperature sensor 22, the outside air temperature detected by the outside air temperature sensor 23, and the incoming water temperature detected by the incoming water temperature sensor 24 are stored. Thereafter, as the boiling operation proceeds, the water in the lower part of the hot water storage tank 2 is circulated to the heat pump unit 3, and hot water heated to the boiling target temperature from the upper part of the hot water storage tank 2 is stacked and stored. Whether the hot water temperature sensor 12 detects that the required amount of hot water or heat has been boiled in the hot water storage tank 2, or detects the hot water temperature detected by the incoming water temperature sensor 24 above a predetermined high temperature that is difficult to boil, Alternatively, when the midnight time period ends, the hot water storage control means 13 issues a stop instruction to the heating control means 26 to stop the boiling operation, and the heating control means 26 drives the compressor 14, the outdoor fan 19 and the circulation pump 20. Is stopped, and the boiling operation is finished.

Next, the operation when the boiling operation in the midnight time zone is performed after the boiling temperature sensor 25 itself has failed will be described with reference to the flowchart of FIG.
The failure determination means 27 determines whether or not the boiling temperature sensor 25 itself has failed based on the temperature detected by the boiling temperature sensor 25 when the boiling operation is stopped or when the boiling operation is started (step S1). ), When it is determined that the boiling temperature sensor 25 itself has failed, an error notification is given, and the heating control means 26 determines whether or not there is an instruction to start the heating operation at midnight from the hot water storage control means 13. (Step S2).

  In step S2, if the heating control means 26 determines from the hot water storage control means 13 that there is an instruction to start the heating operation at midnight, the operation is performed when the heating operation at the midnight time period immediately before the heating temperature sensor 25 fails is stable. The heat pump unit 3 and the circulation pump 20 are based on the values stored in the state storage means 28, that is, the values of the rotation speed of the compressor 14, the rotation speed of the circulation pump 20, the discharge temperature, the outlet temperature, the outside air temperature, and the incoming water temperature. Is controlled to start an alternative boiling operation for boiling hot water in the hot water storage tank 2 (step S3).

  When the alternative boiling operation is started, the heating control unit 26 controls the compressor 14 using the rotation speed of the compressor 14 stored in the operation state storage unit 28 as a target value, and also stores the operation state storage unit 28 in the operation state storage unit 28. The circulation pump 20 is controlled using the stored number of revolutions of the circulation pump 20 as a target value, and further, the refrigerant discharge temperature detected by the discharge temperature sensor 21 is expanded so as to become the discharge temperature stored in the operation state storage means 28. The opening degree of the valve 16 is controlled. The heating control means 28 is the discharge temperature at which the refrigerant boiling temperature detected by the discharge temperature sensor 21 is stored in the operation state storage means 28 when the alternative boiling operation is stable, that is, after a predetermined time has elapsed from the start of the alternative boiling operation. Is reached, the number of revolutions of the circulation pump 20 that rotates at the target value is controlled so that the outlet temperature detected by the refrigerant outlet temperature sensor 22 becomes the outlet temperature stored in the operation state storage means 28. By correcting the number of revolutions, the boiling operation is smoothly performed closer to the movement at the time of stable heating operation before the boiling temperature sensor 25 breaks down.

  Then, the heating control means 26 determines whether or not the outside air temperature detected by the outside air temperature sensor 23 is higher than a value of the outside temperature stored in the operation state storage means 28 during the alternative boiling operation, Alternatively, it is determined whether or not the incoming water temperature detected by the incoming water temperature sensor 24 has become a predetermined temperature or more higher than the incoming water temperature value stored in the operation state storage means 28 (step S4), and the outside air detected by the outside air temperature sensor 23. If it is determined that the temperature or the incoming water temperature detected by the incoming water temperature sensor 24 is higher than the stored value by a predetermined temperature (for example, 5 ° C.) or more, the compressor 14, the outdoor fan 19 and the circulation pump 20 are stopped, and the alternative boiling is performed. The operation is stopped (step S5), and the boiling operation is terminated.

Here, it supplements about the process of step S4.
The outside air temperature during the heating operation in the midnight time zone varies depending on the day, and it cannot be said that the temperature is the same on the previous day and the current day. Then, an alternative boiling operation that operates the compressor 14, the expansion valve 16, and the circulation pump 20 based on the boiling operation when the value is stored in the operation state storage unit 28 and the value stored in the operation state storage unit 28. Depending on the time of operation, the boiling temperature of hot water after heat exchange with the water / refrigerant heat exchanger 15 varies. For example, the incoming water temperature detected by the incoming water temperature sensor 24 during the alternative boiling operation is the same value as the incoming water temperature stored in the operation state storage means 28, and the outside air temperature detected by the outside air temperature sensor 23 during the alternative boiling operation is stored in the operation state. When the temperature is higher than the outside air temperature stored in the means 28, the boiling temperature during the alternative boiling operation becomes higher than that during the boiling operation when the value is stored in the operation state storage means 28. Therefore, the further away from the value stored in the operation state storage means 28, the farther the boiling temperature is, and the further away from the high temperature side, the higher the risk of high temperature abnormality or high pressure abnormality at the heat pump unit 3 side. Therefore, the alternative boiling operation is continued only when it is close to the state at the time of stable boiling operation stored in the operation state storage means 28, and the alternative boiling operation is stopped when leaving the state. The boiling operation can be finished in a safe state before a failure such as an abnormality (for example, an abnormality in high pressure) or a failure occurs in the instrument.

  Further, even when the incoming temperature of the hot water flowing into the water / refrigerant heat exchanger 15 changes, the boiling temperature of the hot water after the heat exchange in the water / refrigerant heat exchanger 15 changes. During normal boiling operation, the temperature of incoming water flowing into the water-refrigerant heat exchanger 15 rises as the boiling of hot water in the hot water storage tank 2 approaches the end. In accordance with this, the heating control means 26 compresses the compressor 14, the expansion valve 16 and the circulation pump 20 so that the temperature of the hot water heated by the water refrigerant heat exchanger 15 detected by the boiling temperature sensor 25 becomes the boiling target temperature. To control. During the alternative boiling operation, the heating control unit 26 controls the boiling operation based on the value stored in the operation state storage unit 28, and the boiling of the hot water in the hot water storage tank 2 is nearing the end. When the incoming water temperature flowing into the water refrigerant heat exchanger 15 becomes higher than the incoming water temperature stored in the operation state storage means 28, the boiling temperature also increases. Therefore, the farther away from the value stored in the operation state storage means 28, the farther the boiling temperature becomes, and the farther away from the high temperature side, the higher the temperature of the heat pump unit 3 or the risk of high pressure abnormality. Become. However, when the alternative boiling operation is performed, it is not necessary to boil the hot water in the hot water storage tank 2 to the end, and it is only necessary to store hot water that can be used for hot water supply in the hot water storage tank 2 to some extent. When the boiling operation of the midnight time zone stored in the storage means 28 is close to the stable state, the alternative boiling operation is continued. The boiling operation can be terminated in a safe state before a malfunction such as a high-pressure abnormality (for example, high pressure abnormality) occurs.

  When the boiling temperature sensor 25 itself described above has failed and the failure determination means 27 determines that the boiling temperature sensor 25 itself has failed for the heating operation at midnight, the heating control means 26 By performing the alternative boiling operation based on the value stored in the operation state storage means 28 when the boiling operation is stabilized in the midnight time zone immediately before the boiling temperature sensor 25 fails, the boiling temperature sensor 25 immediately before the boiling temperature sensor 25 fails. Boiling operation can be performed quickly and smoothly following the movement at the time of boiling operation during midnight hours, and the situation where there is no hot water that can be used for hot water supply in the hot water storage tank 2 in the morning is avoided. This is something that does not make the user feel inconvenient.

  Note that the present invention is not limited to the embodiment described above. In this embodiment, the midnight time zone after the failure determination means 27 determines that the boiling temperature sensor 25 itself has failed. When the heating operation is performed, the heating control means 26 performs the alternative boiling operation based on the value stored in the operation state storage means 28. However, the heating control means 26 is not limited to the midnight time zone, but is also the daytime time zone. However, the alternative boiling operation may be performed, and by doing so, it is possible to suppress the situation that there is no hot water that can be used for hot water supply or the like in the hot water storage tank 2 until the boiling sensor 25 is repaired. This does not cause the user to feel inconvenient.

  In this embodiment, the process of step S4 is performed during the alternative boiling operation, but may be performed at the start of the alternative boiling operation, and by doing so, the midnight stored in the operation state storage unit 28 is obtained. Only when the boiling operation is stable during the time period, the alternative boiling operation is performed, and when the operation is away from the state, the alternative boiling operation is stopped. The boiling operation can be finished in a safe state before a trouble such as a failure occurs.

  In this embodiment, the heating control means 26 is used as the control means. However, the hot water storage control means 13 may be used as the control means, and the hot water storage control means 13 and the heating control means 26 are integrated and controlled. The means may be configured. Further, although the failure determination means 27 and the operation state storage means 28 are included in the heating control means 26, these may be included in the hot water storage control means 13, and the failure determination means 27 and the operation state storage means 28 are included. May be provided in the hot water storage tank unit 1 or in the heat pump unit 3 independently of the hot water storage control means 13 and the heating control means 26.

2 Hot water storage tank 3 Heat pump unit 4 Circulation circuit 14 Compressor 15 Water refrigerant heat exchanger 16 Expansion valve 17 Air heat exchanger 18 Heat pump circuit 20 Circulation pump 21 Discharge temperature sensor 22 Refrigerant outlet temperature sensor 23 Outside air temperature sensor 24 Incoming water temperature sensor 25 Boiling temperature sensor 26 Heating control means 27 Failure determination means 28 Operating state storage means

Claims (4)

  A heat pump unit having a heat pump circuit in which a compressor, a water refrigerant heat exchanger, an expansion valve, and an air heat exchanger are annularly connected by refrigerant piping, a hot water storage tank for storing hot water, the hot water storage tank, and the water refrigerant heat exchanger A circulation circuit in which the water side is annularly connected by hot water piping, a circulation pump provided in the middle of the circulation circuit, a discharge temperature detecting means for detecting a discharge temperature of the refrigerant discharged from the compressor, and the water refrigerant A boiling temperature detecting means for detecting the boiling temperature of hot water after heat exchange by the heat exchanger, and the heat pump unit and the circulation pump so that the detected temperature of the boiling temperature detecting means becomes a boiling target temperature. In a heat pump type hot water heater comprising a control means for performing a boiling operation to boil hot water in the hot water storage tank by controlling, the temperature detected by the boiling temperature detecting means Failure determination means for determining whether or not the boiling temperature detection means itself is a failure, the rotation speed of the compressor when the heating operation is stable during the boiling operation, the rotation speed of the circulation pump, An operation state storage unit that stores each value of the discharge temperature, and when the boiling operation is performed after the failure determination unit determines that the boiling temperature detection unit itself has failed, the control The means is configured to perform an alternative boiling operation for boiling hot water in the hot water storage tank based on a value stored in the operation state storage means.   The control means controls the compressor using the rotation speed of the compressor stored in the operation state storage means as a target value, and sets the rotation speed of the circulation pump stored in the operation state storage means as a target value. And controlling the circulation pump, and further controlling the opening of the expansion valve so that the discharge temperature of the refrigerant detected by the discharge temperature detection means becomes the discharge temperature stored in the operation state storage means. 2. The heat pump type hot water supply apparatus according to claim 1, wherein the heating operation is performed.   The heat pump type water heater according to claim 2, further comprising refrigerant outlet temperature detecting means for detecting an outlet temperature of the refrigerant after heat exchange with the water refrigerant heat exchanger, wherein the operation state storage means is at the time of stable boiling operation. The outlet temperature of the refrigerant detected by the refrigerant outlet temperature detecting means becomes the outlet temperature stored in the operation state storage means when the alternative boiling operation is stable. As described above, a heat pump type hot water heater in which the number of rotations of the circulating pump rotating at the target value is controlled to increase or decrease.   The heat pump type hot water supply apparatus according to any one of claims 1 to 3, wherein an outside air temperature detecting means for detecting an outside air temperature and an incoming water for detecting an incoming temperature of hot water before heat exchange with the water-refrigerant heat exchanger. Temperature detecting means, and the operation state storage means stores the values of the outside air temperature and the incoming water temperature when the boiling operation is stable during the boiling operation, and the control means is configured to start the alternative boiling operation. Or, during the alternative boiling operation, when the outside air temperature detected by the outside air temperature detecting means or the incoming water temperature detected by the incoming water temperature detecting means is higher than a value stored in the operating state storage means by a predetermined temperature or more. A heat pump type water heater configured to stop the alternative boiling operation.

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