JP5324826B2 - Heat pump type water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus that heats hot water supply water by, for example, a heat pump circuit.

  Conventionally, as this type of heat pump type hot water supply device, after the refrigerant discharged from the compressor is circulated to the water heat exchanger (gas cooler), it is circulated to the evaporator via an expansion valve whose opening degree can be adjusted. A heat pump circuit for sucking in, a hot water supply circuit for heating the hot water supply water by the refrigerant of the heat pump circuit by circulating hot water supply water to the water heat exchanger by a pump, and a hot water storage tank for storing hot water for the hot water supply circuit heated by the heat pump circuit The hot water of a hot water storage tank is supplied to a bathtub or a kitchen (for example, refer patent document 1).

Further, in this hot water supply apparatus, when performing defrosting of the evaporator, the defrosting operation is performed by increasing the opening of the expansion valve and raising the temperature of the refrigerant flowing into the evaporator more than the normal operation. I am doing so.
JP 2007-40555 A

  By the way, immediately after starting the defrosting operation of the hot water supply device, the water heat exchanger itself is at a high temperature, and there remains residual heat that can heat the hot water for the hot water supply circuit. When the operation is started, the pump of the hot water supply circuit is stopped, so that the remaining heat of the water heat exchanger cannot be used for heating the hot water supply water, and there is a problem that heat energy is lost correspondingly.

  The present invention has been made in view of the above problems, and its object is to provide a heat pump type hot water supply device that can effectively use the residual heat remaining in the water heat exchanger when defrosting operation is started. Is to provide.

  In order to achieve the above object, the present invention provides a heat pump circuit that circulates refrigerant discharged from a compressor to a hydrothermal exchanger, and then circulates it to an evaporator via an expansion valve whose opening is adjustable, and sucks it into the compressor. And a hot water supply circuit that heats the hot water supply water by the refrigerant of the heat pump circuit by circulating the hot water supply water to the water heat exchanger by a pump, and a hot water storage tank that stores the hot water supply water of the hot water supply circuit heated by the heat pump circuit, In the case of performing defrosting of the evaporator, in the heat pump hot water supply apparatus in which defrosting operation is performed to increase the temperature of the refrigerant flowing through the evaporator by increasing the opening of the expansion valve, the defrosting When the operation is started, there is provided control means for continuously operating the pump of the hot water supply circuit until the defrosting operation is completed with the flow rate at the start of the defrosting operation.

Thus, since the operation of the pump of the hot water supply circuit is continued even when the defrosting operation is started, the hot water supply water of the hot water supply circuit is heated by the residual heat remaining in the water heat exchanger immediately after the start of the defrosting operation. Can do. At that time, for example, even if the flow rate of the pump at the start defrosting operation is controlled so as to decrease the low flow rate by the capacity reduction due to the frost of the evaporator, the operation of the left pump of the flow rate is continued Therefore, after the residual heat of the water heat exchanger is recovered, the low temperature hot water supply water does not flow into the water heat exchanger suddenly.

  In order to achieve the above object, the present invention distributes the refrigerant discharged from the compressor to the water heat exchanger, then distributes it to the evaporator via an expansion valve whose opening degree can be adjusted, and sucks it into the compressor. A heat pump circuit, a hot water supply circuit that heats hot water supply water by a refrigerant of the heat pump circuit by circulating hot water supply water to a water heat exchanger by a pump, and a hot water storage tank that stores hot water supply water of the hot water supply circuit heated by the heat pump circuit In the heat pump hot water supply apparatus that performs the defrosting operation to increase the temperature of the refrigerant flowing through the evaporator by increasing the opening degree of the expansion valve when performing defrosting of the evaporator, When the defrosting operation is started, the flow rate of the pump of the hot water supply circuit is gradually decreased to a predetermined flow rate, and thereafter, the control means is continuously operated until the defrosting operation is finished with the flow rate.

Thus, since the operation of the pump of the hot water supply circuit is continued even when the defrosting operation is started, the hot water supply water of the hot water supply circuit is heated by the residual heat remaining in the water heat exchanger immediately after the start of the defrosting operation. Can do. At that time, even when the flow rate of the pump is not controlled so as to decrease to a small flow rate due to capacity reduction due to frosting of the evaporator at the start of the defrosting operation, the pump flow rate at the start of the defrosting operation is reduced to a predetermined flow rate Therefore, after the residual heat of the water heat exchanger is recovered, the low temperature hot water supply water does not flow into the water heat exchanger suddenly. Moreover, since the flow rate of the pump gradually decreases, a flow rate for recovering the residual heat of the water heat exchanger immediately after the start of the defrosting operation is sufficiently ensured as compared with a case where the flow rate is immediately decreased to a predetermined flow rate.

  According to the present invention, since the hot water for the hot water supply circuit can be heated by the residual heat remaining in the water heat exchanger immediately after the start of the defrosting operation, the heat energy can be used effectively and the COP can be improved. Is very advantageous. In this case, after the residual heat of the water heat exchanger is recovered, the low temperature hot water supply water does not flow into the water heat exchanger suddenly, so that the defrosting refrigerant is removed by the hot water supply water flowing through the water heat exchanger. A decrease in defrosting efficiency can be prevented without lowering the temperature.

  1 to 3 show a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a hot water supply apparatus, FIG. 2 is a block diagram showing a control system, and FIG. 3 is a time chart showing the operation of a control unit. It is.

  The hot water supply apparatus shown in the figure includes a heat pump circuit 10 that circulates refrigerant, a first hot water supply circuit 20 that circulates hot water, a second hot water circuit 30 that circulates hot water, and a bathtub circuit 40 that circulates bathtub water. Heat exchange between the first water heat exchanger 50 that exchanges heat between the refrigerant of the heat pump circuit 10 and the hot water supply water of the first hot water supply circuit 20, the hot water supply water of the second hot water supply circuit 30, and the bathtub water of the bathtub circuit 40. And a second water heat exchanger 60.

  The heat pump circuit 10 is formed by connecting a compressor 11, an expansion valve 12, an evaporator 13 and a first water heat exchanger 50. As shown by solid line arrows in the figure, the compressor 11, the first water heat exchanger 50, The refrigerant is circulated in the order of the expansion valve 12, the evaporator 13, and the compressor 11. The refrigerant used in the heat pump circuit 10 is a natural refrigerant such as carbon dioxide. The expansion valve 12 is composed of, for example, a well-known electronic expansion valve, and the opening degree can be arbitrarily adjusted. The evaporator 13 has a blower 13a, and heat exchange with the outside air is performed by the blower 13a. The evaporator 13 is provided with a temperature sensor 14 for detecting the temperature of the evaporator 13, and an outside air temperature sensor 15 for detecting the outside air temperature is provided in the vicinity of the evaporator 13.

  The first hot water supply circuit 20 is formed by connecting a hot water storage tank 21, a first pump 22 and a first water heat exchanger 50, and as shown by white arrows in the figure, the hot water storage tank 21, the first pump 22, and the first water. The hot water supply water is circulated in the order of the heat exchanger 50 and the hot water storage tank 21. A water supply pipe 23 and a second hot water supply circuit 30 are connected to the hot water storage tank 21, and hot water supplied from the water supply pipe 23 flows through the first hot water supply circuit 20 via the hot water storage tank 21. The hot water storage tank 21 and the bathtub A are connected via a flow path 25 provided with a second pump 24, and the hot water in the hot water storage tank 21 is supplied to the bathtub A by the second pump 24 as shown by a dashed line arrow in the figure. To be supplied. The first hot water supply circuit 20 is provided with a bypass flow path 26 that communicates the inflow side and the outflow side of the hot water storage tank 21, and the flow path is switched between the inflow side of the hot water storage tank 21 and the bypass flow path 26. As a means, a three-way valve 27 is provided. Further, a hot water temperature sensor 28 for detecting the temperature of the hot water supply water is provided between the outflow side of the first water heat exchanger 50 and the three-way valve 27.

  The second hot water supply circuit 30 is formed by connecting the hot water storage tank 21, the third pump 31, and the second water heat exchanger 60. As shown by the broken line arrows in the figure, the hot water storage tank 21, the second water heat exchanger 60, The hot water supply water is circulated in the order of the three pumps 31 and the hot water storage tank 21.

  The circuit 40 for bathtubs connects the bathtub A, the 4th pump 43, and the 2nd water heat exchanger 60, and as shown by the black arrow in the figure, the bathtub A, the 4th pump 43, the 2nd water heat exchanger. The water for bathtubs is circulated in the order of 60 and bathtub A.

  The first water heat exchanger 50 is connected to the heat pump circuit 10 and the first hot water supply circuit 20 to exchange heat between the refrigerant flowing through the heat pump circuit 10 and the hot water supply water flowing through the first hot water supply circuit 20. . Although not shown, the first water heat exchanger 50 has a well-known structure in which the high temperature side circuit 10a of the heat pump circuit 10 is arranged in a tubular pipe wound in an annular shape, and the high temperature side circuit 10a. The hot water for the first hot water supply circuit 20 is heated by heat exchange with the refrigerant.

  The second water heat exchanger 60 is connected to the second hot water supply circuit 30 and the bathtub circuit 40 so as to exchange heat between the hot water supply water of the second hot water supply circuit 30 and the bathtub water of the bathtub circuit 40.

  The hot water supply apparatus includes a heating unit 70 in which the heat pump circuit 10 and the first water heat exchanger 50 are arranged, a hot water storage tank 21, a first pump 22, a second pump 24, a second hot water supply circuit 30, a fourth pump 43, and The tank unit 80 in which the 2nd water heat exchanger 60 is arrange | positioned is provided, and the heating unit 70 and the tank unit 80 are connected via the 1st hot water supply circuit 20. FIG.

  Moreover, the said hot water supply apparatus is provided with the control part 90 which consists of microcomputers, and the control part 90 has the compressor 11, the expansion valve 12, the 1st pump 22, the air blower 13a, the temperature sensor 14, the external temperature sensor 15, and a three-way valve. 27 and a hot water temperature sensor 28 are connected. The control unit 90 determines whether or not the evaporator 13 is frosted based on the temperature of the evaporator 13 detected by the temperature sensor 14 and the outside air temperature detected by the outside air temperature sensor 15. When it is determined that the heating operation is performed, the heating operation (normal operation) is switched to the defrosting operation.

  In the boiling operation of the hot water supply apparatus configured as described above, the compressor 11 is controlled to operate at an arbitrary frequency F as shown in the time chart of FIG. It is controlled so as to be degree B. Further, the blower 13a of the evaporator 13 is operated, and the first pump 22 of the first hot water supply circuit 20 is controlled to operate at an arbitrary flow rate Q.

  When the defrosting operation is started by the control unit 90, the control unit 90 operates the compressor 11 at the predetermined frequency F1 for the defrosting operation after a predetermined time T1 (for example, 30 seconds) has elapsed. When the expansion valve 12 is switched to a predetermined defrosting operation opening B1 larger than that during the boiling operation and a predetermined time T2 (for example, 60 seconds) has elapsed since the start of the defrosting operation, the blower 13a is stopped. When the defrosting operation is started, the operation of the first pump 22 is continued with the flow rate Q at the start of the defrosting operation. Thereby, the hot water for the first hot water supply circuit 20 is heated by the residual heat remaining in the first water heat exchanger 50 and supplied to the hot water storage tank 21. At that time, the flow rate Q of the first pump 22 at the start of the defrosting operation is controlled so as to decrease to a small flow rate due to a decrease in capacity due to frosting of the evaporator 13. By continuing the operation, after the remaining heat of the first water heat exchanger 50 is recovered, the low temperature hot water supply water does not flow into the first water heat exchanger 50 abruptly. Next, when there is no remaining heat and the temperature detected by the hot water temperature sensor 28 is equal to or lower than the set temperature (boiling temperature), the flow path of the first hot water supply circuit 20 is switched to the bypass flow path 26 side by the three-way valve 27. The hot water for the hot water in the circuit 20 does not flow into the hot water storage tank 21 but circulates in the first hot water supply circuit 20 through the bypass passage 26. Thereafter, when the defrosting operation is completed, the first pump 22 is operated at an arbitrary flow rate Q by the control during the boiling operation, and the blower 13a is operated. Next, when a predetermined time T3 (for example, 30 seconds) elapses after the defrosting operation is completed, the expansion valve 12 is switched to an arbitrary opening degree B by the control during the boiling operation, and after the defrosting operation is completed. When a predetermined time T4 (for example, 60 seconds) elapses, the compressor 11 is operated at an arbitrary frequency F by the control during the boiling operation.

  Thus, according to the present embodiment, when the defrosting operation is started, the first pump 22 of the first hot water supply circuit 20 is continuously operated until the defrosting operation is completed with the flow rate Q at the start of the defrosting operation. Therefore, immediately after starting the defrosting operation, the hot water for the first hot water supply circuit 20 can be heated by the residual heat remaining in the first water heat exchanger 50, and the thermal energy can be used effectively. it can. In this case, after the remaining heat of the first water heat exchanger 50 is recovered by continuing the operation of the first pump 22 with the flow rate Q decreased to a small flow rate at the start of the defrosting operation, the first water heat exchanger is recovered. 50 does not suddenly flow into the hot water supply water, so that the temperature of the defrosting refrigerant is not lowered by the hot water supply water flowing through the first water heat exchanger 50 and the defrosting efficiency is prevented from being lowered. can do.

  Further, when the temperature detected by the hot water temperature sensor 28 provided in the inflow side flow path of the hot water storage tank 21 falls below a predetermined set temperature (boiling temperature), the flow path of the first hot water supply circuit 20 is bypassed by the three-way valve 27. Since the first hot water supply circuit 20 is circulated without switching the hot water supply water of the first hot water supply circuit 20 into the hot water storage tank 21 by switching to the 26 side, after the remaining heat of the first water heat exchanger 50 is lost Even if the operation of the first pump 22 is continued, hot water supply water having a temperature lower than the set temperature does not flow into the hot water storage tank 21, and the temperature decrease of the hot water supply water in the hot water storage tank 21 can be prevented.

  FIG. 4 is a time chart showing a second embodiment of the present invention, and a part of the operation of the control unit 90 is different from the above embodiment.

  That is, in the present embodiment, when the defrosting operation is started by the control unit 90, the control unit 90 defrosts the compressor 11 after a predetermined time T1 (for example, 30 seconds) has elapsed, as in the previous embodiment. While operating at a predetermined frequency F1 for operation, the expansion valve 12 is switched to a predetermined opening B1 for defrosting operation that is larger than that during boiling operation, and for a predetermined time T2 (for example, 60 seconds) after the defrosting operation is started. ), The blower 13a is stopped. When the defrosting operation is started, the flow rate of the first pump 22 is gradually decreased to the predetermined flow rate Q1, and then the operation is continued until the defrosting operation is completed with the flow rate Q1. Thereby, the hot water for the first hot water supply circuit 20 is heated by the residual heat remaining in the first water heat exchanger 50 and supplied to the hot water storage tank 21. At this time, since the flow rate of the first pump 22 is reduced to the predetermined flow rate Q1, after the residual heat of the first water heat exchanger 50 is recovered, the low-temperature hot water supply water suddenly flows into the first water heat exchanger 50. There is nothing. Next, when there is no remaining heat and the temperature detected by the hot water temperature sensor 28 is equal to or lower than the set temperature (boiling temperature), the flow path of the first hot water supply circuit 20 is switched to the bypass flow path 26 side by the three-way valve 27. The hot water for the hot water in the circuit 20 does not flow into the hot water storage tank 21 but circulates in the first hot water supply circuit 20 through the bypass passage 26. Thereafter, when the defrosting operation is completed, the first pump 22 is operated at an arbitrary flow rate Q by the control during the boiling operation, and the blower 13a is operated. Next, when a predetermined time T3 (for example, 30 seconds) elapses after the defrosting operation is completed, the expansion valve 12 is switched to an arbitrary opening degree B by the control during the boiling operation, and after the defrosting operation is completed. When a predetermined time T4 (for example, 60 seconds) elapses, the compressor 11 is operated at an arbitrary frequency F by the control during the boiling operation.

  According to the present embodiment, when the defrosting operation is started, the flow rate of the first pump 22 of the first hot water supply circuit 20 is gradually decreased to the predetermined flow rate Q1, and then the flow rate Q1 remains until the defrosting operation is completed. Since the operation is continued, the hot water supply water of the first hot water supply circuit 20 can be heated by the residual heat remaining in the first water heat exchanger 50 immediately after the start of the defrosting operation, as in the above embodiment. , Heat energy can be used effectively. In this case, even when the flow rate Q of the first pump 22 is not reduced to a small flow rate at the start of the defrosting operation, the flow rate of the first pump 22 is reduced to the predetermined flow rate Q1, so that the first water heat exchanger 50 Since the low temperature hot water supply water does not suddenly flow into the first water heat exchanger 50 after the residual heat is recovered, the defrosting is performed by the hot water supply water flowing through the first water heat exchanger 50 as in the above embodiment. It is possible to prevent the defrosting efficiency from being lowered without lowering the temperature of the refrigerant for use. Further, since the flow rate of the first pump 22 is gradually reduced, compared with the case where the flow rate is immediately reduced to the flow rate Q1, the residual heat of the first water heat exchanger 50 is recovered immediately after the start of the defrosting operation. A sufficient flow rate can be ensured, and the hot water supply water can be efficiently heated by residual heat.

Schematic block diagram of a hot water supply apparatus showing a first embodiment of the present invention Block diagram showing the control system Time chart showing the operation of the controller The time chart which shows operation | movement of the control part which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Heat pump circuit, 11 ... Compressor, 12 ... Expansion valve, 13 ... Evaporator, 20 ... First hot water supply circuit, 22 ... First pump, 26 ... Bypass flow path, 27 ... Three-way valve, 50 ... First water heat Exchanger, 90 ... control unit.

Claims (3)

After the refrigerant discharged from the compressor is circulated to the water heat exchanger, it is circulated to the evaporator through an expansion valve whose opening degree can be adjusted, and the heat pump circuit for sucking into the compressor and the hot water supply water are pumped by the water heat exchanger. A hot water supply circuit that heats the hot water supply water by the refrigerant of the heat pump circuit and a hot water storage tank that stores the hot water supply water of the hot water supply circuit heated by the heat pump circuit, and when defrosting the evaporator, In the heat pump type hot water supply apparatus that performs the defrosting operation to increase the temperature of the refrigerant flowing through the evaporator by increasing the opening of the expansion valve,
When the defrosting operation is started, the heat pump type hot water supply device is provided with control means for continuously operating the pump of the hot water supply circuit until the defrosting operation is ended with the flow rate at the start of the defrosting operation. After the refrigerant discharged from the compressor is circulated to the water heat exchanger, it is circulated to the evaporator through an expansion valve whose opening degree can be adjusted, and the heat pump circuit for sucking into the compressor and the hot water supply water are pumped by the water heat exchanger. A hot water supply circuit that heats the hot water supply water by the refrigerant of the heat pump circuit and a hot water storage tank that stores the hot water supply water of the hot water supply circuit heated by the heat pump circuit, and when defrosting the evaporator, In the heat pump type hot water supply apparatus that performs the defrosting operation to increase the temperature of the refrigerant flowing through the evaporator by increasing the opening of the expansion valve,
When the defrosting operation is started, the flow rate of the pump of the hot water supply circuit is gradually reduced to a predetermined flow rate, and then the control means is provided for continuously operating until the defrosting operation is completed with the flow rate. Heat pump type hot water supply device. A bypass passage communicating the inflow side passage and the outflow side passage of the hot water storage tank in the hot water supply circuit;
The flow path switching means for switching the flow path of the hot water supply circuit to the bypass flow path when the temperature of the hot water supply water on the inflow side of the hot water storage tank becomes equal to or lower than a predetermined set temperature is provided. Heat pump water heater.

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