JPH0325106Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a heat pump type heating and water heater, and more specifically, to measures to prevent liquid from returning to the compressor due to defrost operation. (Conventional technology) Conventionally, heat pump type heating and water heaters have been equipped with an air conditioning load side heat exchanger, a heat source side heat exchanger, and a hot water supply side heat exchanger, and during heating operation, the refrigerant circulation system is connected to the heating cycle. The refrigerant from the compressor is circulated under pressure from the air conditioning load side heat exchanger to the heat source side heat exchanger to heat the room, and during hot water supply operation, the refrigerant circulation system is switched to the hot water supply cycle and the refrigerant from the compressor is used to supply hot water. The water in the hot water storage tank is heated by being circulated under pressure from the load side heat exchanger to the heat source side heat exchanger. By the way, if frost forms on the heat exchanger on the heat source side during heating operation or hot water supply operation using such a heat pump heating and water heater, refrigerant Defrosting (melting) is carried out by circulating (for example, see Japanese Utility Model Application Publication No. 55-89963, etc.). However, the above-mentioned conventional device has a disadvantage in that the amount of defrosting heat is small and defrosting takes a long time. For this reason, the refrigerant circulation system is usually switched to a defrost cycle that is the opposite cycle to the heating cycle or the hot water supply cycle, and the refrigerant from the compressor is transferred from the heat source side heat exchanger to the air conditioning load side heat exchanger or the hot water supply load side. By circulating the heat through the heat exchanger under pressure, the amount of heat obtained from the air conditioning load side heat exchanger or the hot water supply load side heat exchanger is given to the heat source heat exchanger for defrosting (melting). (Problem to be solved by the invention) However, in the above case, at the start of defrost operation during heating operation, while the high-pressure liquid refrigerant accumulated in the air conditioning load-side heat exchanger returns to the low-pressure suction port of the compressor, When the heating operation returns again, the high-pressure liquid refrigerant accumulated in the heat source side heat exchanger returns to the suction port of the compressor. Similarly, at the start of defrost operation during hot water supply operation, the high pressure liquid refrigerant accumulated in the heat exchanger on the hot water supply load side is used, and when returning to hot water supply operation, the high pressure liquid refrigerant accumulated in the heat exchanger on the heat source side is transferred to the compressor. It will return to the intake port.
For this reason, the compressor may be damaged due to liquid compression, resulting in a disadvantage that the reliability of the compressor is lowered. In particular, hot water supply operation is often performed at night in winter when heating operation is not performed, so there are many opportunities for defrost operation, and there is a strong demand for improving the reliability reduction of the compressor. The present invention was developed in view of the above, and its purpose is to switch to defrost operation during heating or hot water supply operation as described above, and return to the original heating or hot water supply operation after defrosting is completed. Another objective is to reliably prevent liquid from returning to the compressor. (Means for Solving the Problems) In order to achieve the above object, in the present invention, during heating operation or hot water supply operation immediately before switching from heating operation or hot water supply operation to defrost operation, and during heating operation or hot water supply operation from defrost operation During the defrost operation immediately before returning to normal operation, the high-pressure liquid refrigerant that accumulates between the two heat exchangers that are in use will flow to the heat exchanger that is not in use. In other words, the specific solution of the present invention, as shown in FIG. During heating operation, the refrigerant from the compressor 1 is circulated from the air conditioning load side heat exchanger 2 through the high pressure liquid refrigerant side refrigerant passage 20 to the heat source side heat exchanger 3, and during hot water supply operation, the compressor 1 The hot water supply cycle is such that the refrigerant from the hot water supply load side heat exchanger 5 is circulated through the high pressure liquid refrigerant side refrigerant passage 21 to the heat source side heat exchanger 3, and during the defrost operation in heating operation and hot water supply operation, the heating cycle and hot water supply are performed respectively. This assumes a heat pump heating and water heater that uses a defrost cycle, which is the opposite cycle. Then, the high-pressure liquid refrigerant side refrigerant passage 20 of the heating cycle is connected to the high-pressure liquid refrigerant side refrigerant passage 21 of the hot water supply cycle, and an opening/closing means SV ₉ for heating is provided in the middle.
A hot water supply system in which a heating bypass passage 15a is arranged, and a high pressure liquid refrigerant side refrigerant passage 21 of the hot water supply cycle is connected to a high pressure liquid refrigerant side refrigerant passage 20 of the heating cycle, and an opening/closing means SV ₁₀ for hot water supply is arranged in the middle. At least one of the bypass passages 15b and the heating operation or hot water supply operation immediately before switching from at least one of the heating operation and the hot water supply operation to the defrost operation, and at least one of the heating operation and the hot water supply operation from the defrost operation. During defrost operation immediately before returning to one operation, the corresponding opening/closing means SV ₉ for heating or hot water supply is activated.
The configuration includes a control circuit 13 that operates SV ₁₀ to open, and closes the corresponding opening/closing means SV ₉ and SV ₁₀ at other times, immediately before switching to defrost operation and immediately before returning from defrost operation. This is characterized in that the liquid refrigerant that accumulates during the heating or hot water supply cycle and defrost cycle during operation is made to flow to the side of the heat exchanger that is not operating. (Function) With the above configuration, in the present invention, taking heating operation as an example, during heating operation, the refrigerant that has radiated heat and liquefied in the air conditioning load side heat exchanger 2 is transferred to the high-pressure liquid refrigerant side refrigerant passage of the heating cycle. 20 to the heat source side heat exchanger 3, but during the heating operation immediately before switching from heating operation to defrost operation, the opening/closing means SV ₉ for heating is controlled to open by the control circuit 13, and the heating bypass passage 15a is opened. opens, and as a result, the liquid refrigerant accumulated in the air conditioning load side heat exchanger 2 is
Since the high-pressure liquid refrigerant flows through the high-pressure liquid refrigerant-side refrigerant passage 20 into the high-pressure liquid refrigerant-side refrigerant passage 21 of the hot water supply cycle, there is no accumulation of liquid refrigerant in the air conditioning load-side heat exchanger 2. As a result, when defrost operation is started next, the refrigerant flow will be from the air conditioning load side heat exchanger 2 to the compressor 1, but as there is no accumulation of liquid refrigerant as described above, the refrigerant will be compressed. Liquid return to machine 1 is prevented. In addition, during the defrosting operation described above, the refrigerant that has been radiated, defrosted and liquefied in the heat source side heat exchanger 3 flows into the air conditioning load side heat exchanger 2 via the high pressure liquid refrigerant side refrigerant passage 20 of the heating cycle. However, during the defrost operation immediately before returning from the defrost operation to the heating operation, the heating bypass passage 15a is opened by the opening operation of the opening/closing means SV ₉ for heating in the same manner as described above, and the heat source-side heat exchanger 3 is filled with water. The liquid refrigerant flows through the high-pressure liquid refrigerant side refrigerant passage 20 into the high-pressure liquid refrigerant side refrigerant passage 21 of the hot water supply cycle, and the accumulation of liquid refrigerant in the heat source side heat exchanger 3 is eliminated, so the heating operation is then resumed. Even if the liquid refrigerant does not return to the compressor 1 from the heat source side heat exchanger 3, it is reliably prevented. (Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. Fig. 1 shows the refrigerant piping system of a heat pump type air conditioning/heating water heater, where 1 is a compressor, 2 is an air conditioning load side heat exchanger, 3 is a heat source side heat exchanger, 4 is a hot water storage tank that stores water inside, and 5 7 is an expansion valve through which refrigerant flows from the hot water supply load side heat exchanger 5 to the heat source side heat exchanger 3 for heating the water stored in the hot water storage tank 4; An expansion valve through which refrigerant flows from the exchanger 5 to the air conditioning load side heat exchanger 2; 8 is a liquid receiver; 9 is an accumulator; 10 is an expansion valve that allows refrigerant to flow from the hot water supply load side heat exchanger 5 to the liquid receiver 8; It is a check valve that In addition, SV ₁ is a solenoid valve that opens and closes the refrigerant passage from the compressor 1 to the air conditioning load side heat exchanger 2;
SV ₂ is a solenoid valve that opens and closes the refrigerant passage from the compressor 1 to the heat source side heat exchanger 3; SV ₃ is a solenoid valve that opens and closes the refrigerant passage from the compressor 1 to the hot water supply load side heat exchanger 5;
SV ₄ is a solenoid valve that opens and closes the refrigerant passage from the air conditioning load side heat exchanger 2 to the accumulator 9, SV ₅ is a solenoid valve that opens and closes the refrigerant passage to the expansion valve 6, and SV ₆ is the solenoid valve that opens and closes the refrigerant passage from the heat exchanger 3 on the heat source side to the accumulator 9. SV ₇ is a solenoid valve that opens and closes the refrigerant passage from the hot water supply load side heat exchanger 5 to the accumulator 9, SV ₈ is a solenoid valve that opens and closes the refrigerant passage to the expansion valve 7, 11 12 is a check valve that is installed in the series circuit of the expansion valve 6 and the solenoid valve SV ₅ and allows the refrigerant to flow from the heat source side heat exchanger 3 to the receiver 8; 12 is the expansion valve 7 and the solenoid valve SV ₈ The series circuit is a check valve that is installed in parallel and allows refrigerant to flow from the air conditioning load side heat exchanger 2 to the liquid receiver 8. The check valve 10 that allows the refrigerant to flow from the hot water supply load side heat exchanger 5 to the receiver 8 includes a heating bypass passage 15a that bypasses the check valve 10.
are arranged in parallel, and a solenoid valve SV ₉ as a heating opening/closing means for opening and closing the heating bypass passage 15a is interposed in the middle of the heating bypass passage 15a. By opening the heating bypass passage 15a by opening the solenoid valve SV ₉ , the high-pressure liquid refrigerant side refrigerant passage 20 from the air conditioning load side heat exchanger 2 to the heat source side heat exchanger 3 via the liquid receiver 8 is opened.
is communicated from the liquid receiver 8 to the high-pressure liquid refrigerant side refrigerant passage 21 from the hot water supply load side heat exchanger 5 to the heat source side heat exchanger 3 via the liquid receiver 8 via the heating bypass passage 15a. It is composed of Also, from the air conditioning load side heat exchanger 2 to the liquid receiver 8
The check valve 12 that allows the refrigerant to flow to the hot water supply bypass passage 15b that bypasses the check valve 12.
are arranged in parallel, and a solenoid valve SV ₁₀ is interposed in the middle of the hot water supply bypass passage 15b as an opening/closing means for hot water supply to open and close the hot water supply bypass passage 15b. By opening the hot water supply bypass passage 15b by opening the valve SV ₁₀ , the high-pressure liquid refrigerant side refrigerant passage 21 runs from the hot water supply load side heat exchanger 5 to the heat source side heat exchanger 3 via the liquid receiver 8.
from the liquid receiver 8 through the hot water supply bypass passage 15b, and from the air conditioning load side heat exchanger 2 to the liquid receiver 8.
It is configured to communicate with a high-pressure liquid refrigerant side refrigerant passage 20 that reaches the heat source side heat exchanger 3 through the . Further, the opening and closing of the ten electromagnetic valves SV ₁ to _{SV 10} are controlled by the control circuit 13 . That is, as shown in Tables 1 and 2, during cooling operation, the control circuit 13 switches the refrigerant from the compressor 1 to the high-pressure liquid refrigerant from the heat source side heat exchanger 3 as shown in the first column of Table 1. The room is cooled as a cooling cycle in which the refrigerant is circulated to the air conditioning load side heat exchanger 2 through the side refrigerant passage 20, and during cooling hot water supply operation, the refrigerant from the compressor 1 is switched as shown in the second column of the same table to exchange heat on the hot water supply load side. As a cooling hot water supply cycle that circulates from the heat exchanger 5 to the air conditioning load side heat exchanger 2, it cools the room and at the same time heats the water stored in the hot water storage tank 4 using the heat obtained from the room. The refrigerant from the compressor 1 is transferred to the hot water supply load side heat exchanger 5.
As a hot water supply cycle, the hot water is circulated from the high-pressure liquid refrigerant side to the heat source side heat exchanger 3 via the refrigerant passage 21 on the heat source side, and the water stored in the hot water storage tank 4 is heated. The refrigerant is transferred from the air conditioning load side heat exchanger 2 to the high pressure liquid refrigerant side refrigerant passage 2.
As a heating cycle, the refrigerant from the compressor 1 is circulated through the heat exchanger 3 on the heat source side to heat the room, and in addition, during defrost operation during heating operation, the refrigerant from the compressor 1 is switched to the heat source side heat exchanger 3 as shown in the fifth column of the same table. exchanger 3
As a defrost cycle, which is a reverse cycle of the above-mentioned heating cycle in which the high-pressure liquid refrigerant is circulated from the high-pressure liquid refrigerant to the air conditioning load side heat exchanger 2 through the refrigerant passage 20, the heat source side heat exchanger 3 uses the heat obtained from the room as a heat source. In addition, during defrost operation during heating operation, the refrigerant from the compressor 1 is transferred from the heat source side heat exchanger 3 through the high-pressure liquid refrigerant side refrigerant passage 21 to the hot water supply load side heat exchanger by switching as shown in the second column of Table 2. As a defrost cycle which is a reverse cycle to the above hot water supply cycle in which the hot water is circulated to the hot water tank 5, the hot water in the hot water storage tank 4 is used as a heat source to perform defrosting in the heat source side heat exchanger 3. Then, the control circuit 13 further controls the heating operation as shown in the second column of Table 2 for a predetermined time (T ₁ ) (for example, 10 seconds) during the heating operation immediately before switching from the heating operation to the defrost operation. Solenoid valve for heating and continues opening/closing control during heating.
While opening SV ₉ and closing solenoid valve SV ₇ , for a predetermined time (T ₂ ) (for example, 10 seconds) during defrost operation immediately before returning from the switched defrost operation to heating operation, As shown in the third column of the same table, the opening/closing control of defrost operation during heating operation is continued, and solenoid valve SV ₉ for heating is opened, and furthermore, during hot water heating operation immediately before switching from hot water heating operation to defrost operation. During a predetermined time (T ₃ ) (for example, 10 seconds), the opening/closing control during hot water supply operation is continued, and the solenoid valve SV ₁₀ for hot water supply is opened, and in addition, the defrost operation is performed immediately before returning from defrost operation to hot water supply operation. During a predetermined time (T ₄ ) (for example, 10 seconds) during operation, the opening/closing control of the defrost operation during hot water supply operation is continued, and the solenoid valve SV ₁₀ is opened.

【table】

[Table] In addition, in Tables 1 and 2, ○ indicates opening operation, ×
The mark indicates closed operation. Therefore, when the heating solenoid valve SV ₉ is opened during the heating operation and when the defrost operation is switched from this operation, the high-pressure liquid refrigerant side refrigerant passage 20 of the heating cycle is used to supply hot water via the heating bypass passage 15a. A solenoid valve is connected to the refrigerant passage 21 on the high-pressure liquid refrigerant side of the cycle, and is used during hot water supply operation and during defrost operation after switching from this operation.
When the SV ₁₀ is opened, the high pressure liquid refrigerant side refrigerant passage 21 of the hot water supply cycle is connected to the high pressure liquid refrigerant side refrigerant passage 20 of the heating cycle by the hot water supply bypass passage 15b.
It is configured to communicate and connect to. In addition, in the figure, 14 is a resistor interposed in the heating bypass passage 15a, and 16 is a hot water supply bypass passage 15.
A resistor 17 is installed in the bypass passage 15b during hot water supply and allows the refrigerant to flow in two directions in the air conditioning load side heat exchanger. 18 is a check valve that is closed during installation and is closed after installation. It is a shutoff valve that is opened. Next, to explain the operation of the above embodiment,
During heating operation, the cycle is switched to the heating cycle by opening the solenoid valves SV ₁ , SV ₅ to SV ₇ , so the refrigerant from the compressor 1 is force-fed to the air conditioning load side heat exchanger 2 . After giving heat to the indoor air and liquefying it, the high-pressure liquid refrigerant passes from the refrigerant passage 20 on the liquid receiver 8 and the expansion valve 6 to the heat source side heat exchanger 3.
The indoor air is heated by repeatedly flowing into the heat source side heat exchanger 3 to remove heat from the outdoor air, vaporizing it, and returning from the accumulator 9 to the compressor 1 again. At this time, due to the opening operation of the solenoid valve SV ₇ , the hot water supply load side heat exchanger 5 is communicated with the accumulator 9 and maintained at a low pressure, and at the same time, the solenoid valve SV ₉ for heating is closed and the check valve is closed. Since the refrigerant supply is blocked by 10, the hot water supply load side heat exchanger 5
Liquid refrigerant will not accumulate in the tank. Now, in this state, the predetermined time (T ₁ ) during heating operation corresponds to immediately before switching to defrost operation.
Then, under the control of the control circuit 13, the heating solenoid valve SV ₉ is opened and the solenoid valve SV ₇ is closed. For this reason, the high-pressure liquid refrigerant flowing from the air conditioning load-side heat exchanger 2 to the liquid receiver 8 passes through the heating bypass passage 15a and flows into the high-pressure liquid refrigerant side refrigerant passage 21 of the hot water supply cycle, after which it flows into the high-pressure liquid refrigerant side refrigerant passage 21 of the hot water supply cycle. The liquid refrigerant flows into the hot water supply load side heat exchanger 5 side, thereby eliminating the accumulation of liquid refrigerant in the air conditioning load side heat exchanger 2. When a predetermined time (T ₁ ) has elapsed, the control circuit 13 switches the open/close state of each solenoid valve SV ₁ to _{SV 10} from the second column of Table 2 to the fifth column of Table 1. The defrost cycle is the opposite cycle to the above heating cycle, and the solenoid valve for heating is
SV ₉ operates closed. Therefore, the refrigerant from the compressor 1 is pumped to the heat source side heat exchanger 3, gives heat to the heat source side heat exchanger 3, defrosts and liquefies it, and then flows from the high pressure liquid refrigerant side refrigerant passage 21 to the liquid receiver 8. distributed,
The entire amount passes through the expansion valve 7 to the air conditioning load side heat exchanger 2.
It flows into the air conditioner load side heat exchanger 2, takes heat from the room, vaporizes it, and transfers it from the accumulator 9 to the compressor 1.
Start repeating the process. At this time, since the liquid refrigerant flows into the hot water supply load side heat exchanger 5 side and there is no accumulation of liquid refrigerant in the air conditioning load side heat exchanger 2, the liquid refrigerant flows from the air conditioning load side heat exchanger 2 to the compressor 1. Refrigerant is reliably prevented from returning. Thereafter, as the defrost progresses, at a predetermined time (T ₂ ) before the end of the defrost operation, which corresponds to immediately before returning from the defrost operation to the heating operation, the solenoid valve SV ₉ for heating is controlled by the control circuit 13 and restarts. A part of the liquid refrigerant that is opened and circulated from the heat source side heat exchanger 3 to the liquid receiver 8 via the high pressure liquid refrigerant side refrigerant passage 20 passes through the heating bypass passage 15a and enters the high pressure liquid refrigerant side refrigerant passage of the hot water supply cycle. 20 and flows into the unused hot water supply load side heat exchanger 5 side, so that the liquid refrigerant does not accumulate in the heat source side heat exchanger 3. When the predetermined time (T ₂ ) passes in this state and the defrost operation returns to the heating operation, the open/close states of the solenoid valves SV ₁ to _{SV 10} change from the third column of Table 2 to the fourth column of Table 1. , the heating cycle returns, and the heating solenoid valve SV ₉ closes. Therefore, the refrigerant from the compressor 1 is again sent under pressure to the air conditioning load side heat exchanger 2 and then to the high pressure liquid refrigerant side refrigerant passage 20.
The process of flowing into the heat source side heat exchanger 3 through the liquid receiver 3 and expansion valve 6, and returning from the accumulator 9 to the compressor 1 begins to be repeated. At this time, since the liquid refrigerant flows into the hot water supply load side heat exchanger 5 side and there is no accumulation of liquid refrigerant in the heat source side heat exchanger 3, the liquid refrigerant flows from the heat source side heat exchanger 3 to the compressor 1. There's no going back. The above explained the case during heating operation, but
The same applies to the case of hot water supply operation. That is, during hot water supply operation, the refrigerant from the compressor 1 is transferred to the hot water supply load side heat exchanger 5 during the hot water supply cycle.
The hot water supply load side heat exchanger 5 applies heat to the stored water in the hot water storage tank 4 to liquefy it, and then it is circulated from the high pressure liquid refrigerant side refrigerant passage 21 to the heat source side heat exchanger 3 via the liquid receiver 8. However, at a predetermined time (T ₃ ) during the hot water supply operation immediately before switching to the defrost operation, the solenoid valve SV ₁₀ for hot water supply opens and the liquid refrigerant from the hot water supply load side heat exchanger 5 is activated. flows from the liquid receiver 8 through the hot water supply bypass passage 15b, into the high-pressure liquid refrigerant side refrigerant passage 20 of the heating cycle, and flows into the unused air conditioning load side heat exchanger 2 side, so that the hot water supply load side heat exchanger The accumulation of liquid refrigerant in step 5 is eliminated. Therefore, even if the solenoid valve SV ₁₀ for hot water supply is closed after a predetermined time (T ₃ ) and the defrost cycle is switched to the defrost cycle, which is the opposite cycle to the hot water supply cycle, and the defrost operation is started, the hot water supply load side Return of liquid refrigerant from heat exchanger 5 to compressor 1 is prevented. Also, for a predetermined time (T ₂ ) immediately before returning from the defrost operation to the hot water supply operation, the refrigerant liquefied in the heat source side heat exchanger 3 due to the defrost is received by opening the solenoid valve SV ₁₀ for hot water supply. From the container 8 through the hot water supply bypass passage 15b,
The high-pressure liquid refrigerant flows into the refrigerant passage 20 on the heating cycle side, flows into the unused air conditioning load side heat exchanger 2, and the accumulation of liquid refrigerant in the heat source side heat exchanger 3 disappears, so hot water supply operation is resumed. In some cases, the liquid refrigerant is prevented from returning from the heat source side heat exchanger 3 to the compressor 1. Therefore, during heating operation and hot water supply operation immediately before switching from heating operation and hot water supply operation to defrost operation, and during defrost operation immediately before returning from defrost operation to heating operation and hot water supply operation, liquid refrigerant is supplied to the compressor 1. Compressor 1
reliability can be improved. In addition, in the above embodiment, the heating bypass passage 15
a, a hot water supply bypass passage 15b, a heating solenoid valve SV ₉ for opening and closing the hot water supply bypass passages 15a and 15b, and a hot water supply solenoid valve SV ₁₀ . Although liquid return to the compressor 1 can be prevented both during heating operation and hot water supply operation, the present invention may be configured to prevent liquid return to the compressor 1 only in either one of them. Of course. Further, in the above embodiment, the refrigerant circulation system was switched by opening and closing eight electromagnetic valves SV ₁ to SV ₈ , but in addition, as shown in FIG. 2, two four-way switching valves SV ₁₁ , SV ₁₂ can also be used for similar switching. (Effects of the Invention) As explained above, according to the heat pump type heating and water heater of the present invention, during heating operation or hot water supply operation immediately before switching from at least one of heating operation and hot water supply operation to defrost operation, and During the defrost operation immediately before returning from the defrost operation to at least one of the heating operation and hot water supply operation, the control circuit operates the opening/closing means to open the opening/closing means.
The high-pressure liquid refrigerant between the two heat exchangers in use is made to flow through the bypass passage to the heat exchanger that is not in use, which prevents liquid refrigerant from returning to the compressor due to defrost operation. can be prevented,
This makes it possible to improve the reliability of the compressor.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a refrigerant circuit diagram of a heat pump type air-conditioning/heating water heater, and FIG. 2 is a diagram showing a modification of the refrigerant circuit of FIG. 1. 2... Air conditioning load side heat exchanger, 3... Heat source side heat exchanger, 5... Hot water supply load side heat exchanger, 13... Control circuit, SV ₉ ... Solenoid valve for heating (opening/closing means),
SV ₁₀ ... Solenoid valve for hot water supply (opening/closing means), 15a
...Bypass passage during heating, 15b...Bypass passage during hot water supply, 20...Refrigerant passage on the high pressure liquid refrigerant side of the heating cycle, 21...Refrigerant passage on the high pressure liquid refrigerant side of the hot water supply cycle.

Claims (1)

[Scope of utility model registration request] Comprising a compressor 1, an air conditioning load side heat exchanger 2, a heat source side heat exchanger 3, and a hot water supply load side heat exchanger 5,
During heating operation, the refrigerant from the compressor 1 is circulated from the air conditioning load side heat exchanger 2 to the heat source side heat exchanger 3 via the high pressure liquid refrigerant side refrigerant passage 20, and during hot water supply operation, the refrigerant from the compressor 1 is circulated. from the hot water supply load side heat exchanger 5 to the high pressure liquid refrigerant side refrigerant passage 21
In the heat pump type heating water heater, the hot water is circulated to the heat source side heat exchanger 3 through the heat exchanger 3, and during the defrost operation in the heating operation and the hot water supply operation, the defrost cycle is the opposite cycle to the heating cycle and the hot water supply cycle, respectively. The high-pressure liquid refrigerant side refrigerant passage 20 of the cycle is connected to the high-pressure liquid refrigerant side refrigerant passage 21 of the hot water supply cycle, and there is a heating bypass passage 15a in which opening/closing means SV ₉ for heating is arranged in the middle, and a high-pressure liquid refrigerant passage 21 of the hot water supply cycle. The refrigerant side refrigerant passage 21 is connected to the high pressure liquid refrigerant side refrigerant passage 20 of the heating cycle, and there is an opening/closing means for hot water supply in the middle.
At least one bypass passage with the hot water supply bypass passage 15b in which the SV ₁₀ is arranged, and the heating operation or hot water supply operation immediately before switching from at least one of the heating operation and hot water supply operation to the defrost operation, and from the defrost operation to the heating operation. During the defrost operation immediately before returning to at least one of operation and hot water supply operation, the corresponding opening/closing means SV ₉ and SV ₁₀ for heating or hot water supply are opened, and at other times, the corresponding opening/closing means SV ₉ is opened. , and a control circuit 13 that controls the SV ₁₀ to close. Immediately before switching to defrost operation and immediately before returning from defrost operation, the liquid refrigerant that accumulates during the heating or hot water supply cycle and the defrost cycle is removed. A heat pump type heating/water heater characterized by flowing water to the side of a heat exchanger that is not in operation.