JPH0233108Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a heat pump type heating and water heater.
In particular, this invention relates to an improvement in the defrost operation control of a heat pump heating water heater, in which when an outdoor heat exchanger becomes frosted during heating operation, hot gas, which is a refrigerant, is caused to flow through the outdoor heat exchanger to defrost (melt) the outdoor heat exchanger. . (Prior Art) Conventionally, as shown in FIG. 3, this type of heat pump type air-conditioning/heating water heater has a compressor a, an indoor heat exchanger b, an outdoor heat exchanger c, and a hot water storage tank d. During heating operation, the refrigerant circulation system is switched to the heating cycle and the refrigerant from the compressor a is transferred to the indoor heat exchanger b.
During hot water supply operation, the refrigerant from the compressor a is transferred from the hot water supply heat exchanger e to the outdoor heat exchanger c to heat the room.
A system is known in which hot water in a hot water storage tank d is heated by circulating it under pressure (for example, see Japanese Patent Publication No. 57-43830). When the outdoor heat exchanger c becomes frosted during the heating operation using the heat pump heating water heater as described above, the refrigerant circulation system is switched to the opposite cycle (cooling cycle) from the heating cycle, and the compressor a
The refrigerant from outdoor heat exchanger c to indoor heat exchanger b
By force-feeding and circulating hot gas as a refrigerant, it is defrosted by flowing it into the outdoor heat exchanger c. (Problem to be solved by the invention) However, in the conventional system described above, since the refrigerant circulation system is a cooling cycle, the defrost operation is usually performed by stopping the indoor fan to avoid excessively cooling the room. done in the state. As a result, the amount of heat acquired by the indoor heat exchanger b decreases, the defrost time becomes longer, and the room is also cooled to some extent, making it impossible to provide comfortable heating. The present invention was developed in consideration of these points, and focused on using the heat of hot water in the hot water storage tank as a defrosting heat source.When frosting occurs during heating operation, the refrigerant from the compressor is transferred from the outdoor heat exchanger. By circulating the heat through the hot water supply heat exchanger under pressure, a large amount of heat is collected in the hot water heat exchanger, shortening the defrosting time, and providing comfortable heating without causing a drop in indoor temperature. The purpose is to make it possible to do so. At that time, if the water temperature in the hot water storage tank is low, there is a high risk that the hot water storage tank will freeze and the hot water heat exchanger will be damaged. Defrost operation that uses the hot water heat exchanger as a heat source is stopped, and defrost operation that uses the indoor heat exchanger as a heat source is performed as before to provide comfortable heating while preventing damage to the hot water heat exchanger. It is intended to do so. (Means for Solving the Problem) In order to achieve this object, the solving means of the present invention connects a compressor 1, an indoor heat exchanger 2, and an outdoor heat exchanger 3 in order, as shown in FIG. It is equipped with a heating refrigerant circuit capable of reverse cycle operation, and a hot water supply refrigerant circuit capable of reverse cycle operation, which is formed by sequentially connecting the compressor 1, the hot water supply heat exchanger 5, and the outdoor heat exchanger 3. . Furthermore, a switching means is provided for switching the connection of both the refrigerant circuits and switching each refrigerant circuit to a reverse cycle. Then, the temperature near the hot water supply heat exchanger 5 is detected, and when the temperature is above a predetermined temperature, a hot water supply heat exchanger selection signal is output, while when the temperature is lower than the predetermined temperature, an indoor heat exchanger selection signal is output. The temperature detector 11 outputs the temperature, and the frost detection device 12 detects when the outdoor heat exchanger 3 is frosted during heating operation. Then, when the frost detection device 12 outputs a detection signal and receives a hot water supply heat exchanger selection signal from the temperature detector 11, the hot water supply refrigerant circuit is set to the hot water supply heat exchanger 5 as a heat source. In the reverse cycle, when an indoor heat exchanger selection signal is received from the temperature detector 11, the heating refrigerant circuit is set to a reverse cycle with the indoor heat exchanger 2 as the heat source, and the outdoor heat exchanger 2 is defrosted. A control circuit 13 is provided for controlling the switching means as shown in FIG. (Function) As a result, in the present invention, the frost detection device 1
When the detection signal 2 is output, if the temperature of the hot water in the hot water storage tank is higher than a predetermined temperature, the hot water supply refrigerant circuit is switched to the hot water supply heat exchanger circuit under the control of the control circuit 13 in response to the hot water supply heat exchanger selection signal from the temperature detector 11. Defrost operation is performed in a reverse cycle using the heat exchanger 5 as a heat source. On the other hand, when the water temperature in the hot water storage tank is lower than the predetermined temperature, the indoor heat exchanger selection signal from the temperature detector 11 is received and the control circuit 13 controls the heating refrigerant circuit to use the indoor heat exchanger 2 as the heat source. The defrost operation is performed in reverse cycle. (Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. Figure 1 shows the refrigerant piping system of a heat pump type air conditioning/heating water heater, where 1 is a compressor, 2 is an indoor heat exchanger,
3 is an outdoor heat exchanger, 4 is a hot water tank for storing water therein, and 5 is a hot water supply heat exchanger for heating the water stored in the hot water tank 4. 6 is the above indoor heat exchanger 2
and an expansion valve through which the refrigerant flows from the hot water supply heat exchanger 5 to the outdoor heat exchanger 3; and 7, an expansion valve through which the refrigerant flows from the hot water supply heat exchanger 5 and the outdoor heat exchanger 3 to the indoor heat exchanger 2. , 8 is a liquid receiver, and 9 is an accumulator. Also, SV ₁ is a solenoid valve that opens and closes the refrigerant passage from the compressor 1 to the indoor heat exchanger 2, SV ₂ is a solenoid valve that opens and closes the refrigerant passage from the compressor 1 to the outdoor heat exchanger 3, and SV ₃ is a compression valve. From machine 1 to hot water heat exchanger 5
SV ₄ is a solenoid valve that opens and closes the refrigerant passage from the indoor 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 a solenoid valve that opens and closes the refrigerant passage from the indoor heat exchanger 2 to the accumulator 9. SV 7 is a solenoid valve that opens and closes the refrigerant passage from the liquid receiver 8 to the heat exchanger 5 for hot water supply, SV ₇ is a solenoid valve that opens and closes the refrigerant passage from the outdoor heat exchanger 3 to the accumulator 9, and SV ₈ is the heat exchanger for hot water supply. a solenoid valve that opens and closes a refrigerant passage from 5 to an accumulator 9;
SV ₉ is a solenoid valve that opens and closes the refrigerant passage to the expansion valve 7;
SV ₁₀ is a solenoid valve that opens and closes the refrigerant passage from the compressor 1 to the indoor heat exchanger 2. As described above, a refrigerant circuit for heating and cooling capable of reverse cycle operation, which is formed by sequentially connecting the compressor 1, the indoor heat exchanger 2, and the outdoor heat exchanger 3, and the compressor 1, the hot water supply heat exchanger 5, and the outdoor heat exchanger are constructed. A refrigerant circuit for hot water supply that can be operated in a reverse cycle by connecting 3 in sequence, a compressor 1, and a heat exchanger 5 for hot water supply.
A refrigerant circuit for cooling and hot water supply is constructed by connecting the indoor heat exchanger 2 and the indoor heat exchanger 2 in this order. In addition, solenoid valve SV ₁ ~
The SV ₁₀ constitutes a switching means for switching the connections between the refrigerant circuits and switching the refrigerant circuits to the reverse cycle. Further, 10 is a control device that controls opening and closing of the ten electromagnetic valves SV ₁ to SV ₁₀ , and the control device 10
10 solenoid valves SV ₁ ~ _{SV 10} as shown in the table below
By opening a predetermined one of them, the operating state can be switched into four ways. In the case of the first column in the table, cooling operation is performed by circulating the refrigerant from the compressor 1 from the outdoor heat exchanger 3 to the indoor heat exchanger 2, and in the case of the second column in the table, the refrigerant from the compressor 1 is circulated to the indoor heat exchanger 2. A cooling hot water supply operation is performed in which the refrigerant from the hot water supply heat exchanger 5 is circulated to the indoor heat exchanger 2 to cool the room, and at the same time hot water in the hot water storage tank 4 is heated by exhaust heat absorbed from the room. In the case of the third column in the table, the refrigerant from the compressor 1 is transferred from the hot water supply heat exchanger 5 to the outdoor heat exchanger 3.
In the case of the fourth column in the table, the refrigerant from the compressor 1 is circulated from the indoor heat exchanger 2 to the outdoor heat exchanger 3 to perform the heating operation. ing.

[Table] In the table, the ○ mark indicates opening operation, and the × mark indicates closing operation.
A temperature detector 11 made of a thermostat is provided in the hot water storage tank 4 to detect the temperature near the hot water supply heat exchanger 5. The temperature detector 11 outputs a hot water supply heat exchanger selection signal as an OFF signal when the temperature near the hot water supply heat exchanger 5 is higher than a predetermined temperature (for example, 3° C.), and outputs a hot water supply heat exchanger selection signal as an OFF signal when the temperature is lower than the predetermined temperature. It is configured to output an indoor heat exchanger selection signal as an ON signal. Reference numeral 12 denotes a frost detection device equipped with a de-icer that detects frost in the outdoor heat exchanger 3 and generates a detection signal, and the frost detection device 12 is used only during heating operation by the control device 10; The configuration is such that the detection signal from the de-Icer can be output to the outside only when the solenoid valve SV ₁ is opened. Further, 13 is a control circuit that receives a detection signal from the frost detection device 12 and a hot water supply heat exchanger selection signal or an indoor heat exchanger selection signal from the temperature detector 11, and the control circuit 13 includes: When the detection signal is output from the frost detection device 12 and the hot water supply heat exchanger selection signal is received from the temperature sensor 11, the solenoid valves SV ₁ to _{SV 10} are set as shown in the fifth column in the table above. By controlling opening and closing,
The hot water supply refrigerant circuit is connected to the hot water supply heat exchanger so that the refrigerant pumped from the compressor 1 flows into the outdoor heat exchanger 3 and then returns to the compressor 1 via the liquid receiver 8, the hot water supply heat exchanger 5, and the hot water supply heat exchanger 5. The outdoor heat exchanger 3 is defrosted by switching to a reverse cycle using the heat source 5 as the heat source. On the other hand, when the indoor heat exchanger selection signal is received from the temperature detector 11, the solenoid valves SV ₁ to SV ₁₀ are controlled to open and close as shown in the sixth column of the table above, so that the compressor 1 is connected to the outdoor heat exchanger. The air-conditioning refrigerant circuit is switched to a cooling cycle so that the refrigerant discharged from the liquid receiver 8 is returned to the compressor 1 via the indoor heat exchanger 2, and the heat source of the indoor heat exchanger 2 is used to transfer the refrigerant to the outdoor heat exchanger 3.
It is configured to defrost. still,
When the refrigerant circulation system is switched by the control circuit 13, the control device 10 is configured to stop the opening/closing control function of each electromagnetic valve SV ₁ to _{SV 10} so as not to switch the refrigerant circulation system. Therefore, in the above embodiment, when frost occurs in the outdoor heat exchanger 3 during heating operation, the control circuit 13 is activated by the external output of the detection signal from the frost detection device 12 to switch the refrigerant circulation system.
When the temperature near the hot water supply heat exchanger 5 is higher than a predetermined temperature, the hot water supply heat exchanger 5 is used as the heat source, and when the temperature is lower than the predetermined temperature, the indoor heat exchanger 2 is used as the heat source.
Since the outdoor heat exchanger 3 is defrosted by reverse cycle defrost operation using the heat source as the heat source, the defrost of the outdoor heat exchanger 3 can be shortened without cooling the room as much as possible and without freezing the hot water tank 4. It can be done efficiently and in a timely manner. That is, when the temperature near the hot water supply heat exchanger 5 is higher than a predetermined temperature, the solenoid valves SV ₂ , SV ₆ , SV ₈ are activated by the control circuit 13 that receives the hot water supply heat exchanger selection signal from the temperature detector 11 . is opened (see the fifth stage in the table above), and the refrigerant is transferred to the hot water supply heat exchanger 5.
After being heated and vaporized by the hot water in the hot water storage tank 4, the compressor 1 sends it under pressure to the outdoor heat exchanger 3 for defrosting, liquefies it in the outdoor heat exchanger 3, and supplies the hot water via the liquid receiver 8. Since the return to the outdoor heat exchanger 5 is repeated, defrosting in the outdoor heat exchanger 3 can be efficiently performed in a short time using the hot water in the hot water storage tank 4 as a heat source. Moreover, since the hot water in the hot water storage tank 4 is used as a heat source, there is no need to cool the room. On the other hand, when the temperature near the hot water supply heat exchanger 5 is lower than the predetermined temperature, or when the temperature near the hot water supply heat exchanger 5 becomes lower than the predetermined temperature due to defrosting using the hot water in the hot water storage tank 4 as a heat source as described above. Sometimes, the solenoid valves SV ₂ , SV ₄ ,
When the SV ₉ is opened, the refrigerant circulation system is switched, and the refrigerant is heated and vaporized by the indoor air in the indoor heat exchanger 2, and then compressed into the outdoor heat exchanger 3 by the compressor 1 and defrosted. Since the process is repeated, the temperature of the hot water in the hot water tank 4 does not drop, and freezing of the hot water tank 4 can be prevented. Furthermore, in order to prevent the temperature of the hot water being supplied from decreasing due to the reverse cycle defrost operation using the hot water supply heat exchanger 5 as a heat source, the hot water supply heat exchanger 5 is arranged at the lower part of the hot water storage tank 4. In addition to installing hot water tank 4
By supplying hot water from the upper part of the inside, you can suppress the drop in temperature of the hot water as much as possible.
More preferred. In addition, in the above embodiment, the refrigerant circulation system was switched by opening and closing ten solenoid valves SV ₁ to _{SV 10} as switching means, but as shown in FIG. Needless to say, switching can be performed in the same manner using the valves 14 and 15. (Effects of the invention) As explained above, according to the invention, when there is frost during heating operation (that is, when the detection signal of the frost detection device is output), when the temperature near the hot water supply heat exchanger is higher than the predetermined temperature, Based on the output of the hot water supply heat exchanger selection signal from the temperature sensor, the control circuit switches to perform a reverse cycle defrost operation using the hot water heat exchanger as the heat source, while maintaining the temperature near the hot water supply heat exchanger at a predetermined level. When the temperature is lower than the above temperature, the control circuit switches to reverse cycle defrost operation using the indoor heat exchanger as the heat source based on the output of the indoor heat exchanger selection signal from the temperature detector, so that the indoor heat exchanger can be used as much as possible. It is possible to shorten the defrost time without cooling the hot water storage tank or freezing the hot water storage tank, thereby enabling comfortable heating.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a refrigerant piping system diagram of a heat pump type air-conditioning/heating water heater, and FIG. 2 is a diagram showing a modified sequence of the refrigerant piping system of FIG. 1. FIG. 3 is a refrigerant piping system diagram of a conventional heating, cooling, and hot water supply system. 2...Indoor heat exchanger, 5...Hot water supply heat exchanger,
11... Temperature detector, 12... Frost detection device, 13... Control circuit.

Claims (1)

[Scope of claims for utility model registration] Compressor 1, indoor heat exchanger 2, and outdoor heat exchanger 3
A heating refrigerant circuit capable of reverse cycle operation, which is formed by sequentially connecting the compressor 1, the hot water supply heat exchanger 5, and the outdoor heat exchanger 3, and which is capable of reverse cycle operation. and a switching means for switching the connection of both refrigerant circuits and switching each refrigerant circuit to the reverse cycle; detecting the temperature near the hot water supply heat exchanger 5, and when the temperature is above a predetermined temperature, a switching means for switching the connection of the two refrigerant circuits to the reverse cycle; A temperature detector 11 that outputs a heat exchanger selection signal while outputting an indoor heat exchanger selection signal when the temperature is lower than a predetermined temperature, and a frost detection unit that detects when the outdoor heat exchanger 3 is frosted during heating operation. When the frost detection device 12 outputs a detection signal and receives a hot water supply heat exchanger selection signal from the temperature detector 11, the hot water supply refrigerant circuit is configured to use the hot water supply heat exchanger 5 as a heat source. In the reverse cycle, when an indoor heat exchanger selection signal is received from the temperature detector 11, the heating refrigerant circuit is switched to the indoor heat exchanger 2.
and a control circuit 13 that switches and controls the switching means to defrost the outdoor heat exchanger 3 in a reverse cycle using a heat source as a heat source.