JP6079507B2 - Hot / cold water air conditioning system - Google Patents

Description

  The present invention relates to operation control based on the temperature of circulating water that supplies and circulates hot / cold water to a heat pump heat source unit, a heat radiator and a hot water storage tank of a heat pump hot / cold water air conditioning system.

  In a heat pump hot water heating system that performs hot water supply and heating using a heat pump cycle, hot water heated from a refrigerant in the heat pump cycle through a heat exchanger is supplied to an indoor radiator and hot water storage tank that performs heating, and then used hot water Is provided with a heating and hot water circulation circuit that returns the heat to the heat exchanger of the heat pump cycle. In order to control the hot water to be supplied, the circulation circuit includes a forward temperature detection means for detecting the forward temperature of the supplied hot water, and a return temperature detection means for detecting the temperature of the hot water returning to the heat exchanger. It has been.

  In the conventional heat pump hot water heating system, the forward temperature control that is easy to control quickly and easily with respect to the change of the heat pump capacity (compressor operating frequency) in the heat pump cycle is performed. However, when the efficiency of the indoor radiator on the load side of the hot water heating system is poor or when the required air conditioning hot water supply load is small, such as in the middle of the season, the minimum capacity operation by the compressor operating frequency control on the heat pump cycle heat source side However, when the capacity heat amount supplied by the minimum capacity operation is larger than the heat dissipation amount on the air-conditioning hot water supply load side, the circulatory circuit going temperature exceeds the target going temperature, so the responsiveness is fast. Therefore, it becomes an ON / OFF cycle operation of the compressor operation.

  When falling into such an ON / OFF cycle operation state, not only the efficiency as a heat pump is bad, but also the pressure of the refrigerant circuit accompanying frequent ON / OFF switching and the opening / closing of the relay contacts of the electric circuit cause the compressor to It may lead to shortening of the life of the refrigerant circuit parts and electric circuit parts included.

  The ideal solution to this problem is to ensure that the minimum heat capacity of the heat pump heat source is the same no matter how small the amount of heat released (in the case of hot water heating) or the amount of heat absorbed (in the case of cold water cooling) on the air conditioning hot water supply load side. The compressor may be operated at a lower operating frequency. However, a lower limit is set for the operating frequency of the compressor because of the reliability of the compressor, and there is a limit in this correspondence.

  Therefore, in the conventional heat pump hot water heating system, for example, when it is determined that the heating load has decreased, the control to lower the return temperature by starting the flow rate of the circulating water by lowering the rotation speed of the circulating pump for heating is started, After that, there is a control that operates a mixing valve so as to lower the going-out temperature, opens a bypass flow path, and joins a part of discharged hot water (for example, refer to Patent Document 1).

  Further, for example, in another conventional heat pump hot water heater, after the heat pump is started, the number of rotations of the heating circulation pump is increased stepwise to stabilize the heat pump cycle, and first the outgoing temperature becomes the target temperature. The number of rotations of the circulation pump is controlled, and then the number of rotations of the circulation pump is controlled so that the return temperature becomes the target temperature (see, for example, Patent Document 2).

JP 2010-008036 A (page 7-12, FIG. 1-10) JP 2012-112583 (page 4-9, FIG. 1-5)

  However, the water circulation pump used in the hot water heating system can only be handled if it is a DC drive type that can control the number of revolutions. In addition, the complexity of the control algorithm accompanying the realization of water flow control makes it possible to handle these products. Is expensive.

  The present invention has been made to solve the above-described problems. Although the rotational speed control is not possible, the AC power supply type water circulation pump that can cope with a low cost and a relatively simple control algorithm can be used. An object of the present invention is to provide a hot / cold water air conditioning system capable of suppressing the ON / OFF cycle operation of a heat pump heat source.

The hot / cold water air conditioning system according to the present invention forms a water circuit by annularly connecting a heat pump heat source, a hot / cold water air conditioner, and a circulation pump with piping, and supplies hot water or cold water from the heat pump heat source to the hot / cold water air conditioner. Alternatively, in a hot / cold water air conditioning system for performing cold water cooling, a water temperature sensor is provided at an outlet of a water circuit for circulating hot water or cold water generated by the heat pump heat source to the hot / cold water air conditioner, and the heat pump heat source side of the water circuit of the provided water temperature sensor returns to the inlet, the forward water temperature control for controlling the heat pump heat source by a difference in forward sensed by prior Symbol forward temperature sensor temperature detection temperature Tm and (out) and the target forward water temperature Tt (out), wherein The return water temperature detection temperature Tm (in) detected by the return water temperature sensor and the target return water temperature Tt (in). A control device for switching the return water temperature control for controlling the heat pump heat source, the said control device, said outward when the water temperature is detected by the sensor forward temperature detected temperature Tm (out) of the target forward water temperature Tt (out) hereinafter Determination based on a thermo ON / OFF operation in which the compressor of the heat pump heat source is operated and the compressor is stopped when the outgoing water temperature detection temperature Tm (out) becomes equal to or higher than the target outgoing water temperature Tt (out) by a predetermined value α. Is determined as the determination count number, and when the determination count number is equal to or greater than a predetermined value, it is determined that the minimum supply capacity of the heat pump heat source exceeds the required heat quantity of the hot / cold water air conditioner, and Switch to return water temperature control .

  The hot / cold water air-conditioning system of the present invention is ON even when the minimum capacity of the heat pump heat source by the compressor operating frequency control is larger than the heat dissipation amount (in the case of hot water heating) or the heat absorption amount (in the case of cold water cooling) of the hot / cold water air conditioning equipment. / OFF cycle operation can be suppressed, and it has the effect of providing a high-efficiency and long-life hot / cold water air conditioning system.

  In addition, since there is no need to control the number of rotations of the circulation pump provided in the circulation channel, an AC power supply type water circulation pump with constant speed rotation can be used, and the control algorithm can be made relatively simple and low cost. Have.

It is a water circuit diagram of the hot / cold water air conditioning system in Embodiment 1 of this invention. It is a block diagram of the heat pump heat source in Embodiment 1 of this invention. It is a flowchart which shows the control operation | movement of the hot water heating operation or the cold water cooling operation of the hot / cold water air-conditioning system in the actual form 1 of this invention. It is a time chart which shows the compressor driving | running state of the hot-water heating operation of the hot / cold water air-conditioning system in the conventional control in connection with the actual form 1 of this invention. It is a time chart figure which shows the compressor driving | running state of the hot water heating operation of the hot / cold water air-conditioning system in the actual form 1 of this invention. It is a water circuit diagram of the hot / cold water air-conditioning system in the actual form 2 of this invention. It is a water circuit diagram of the hot / cold water air-conditioning system in the actual form 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a water circuit diagram showing a hot / cold water air conditioning system according to Embodiment 1 of the present invention. The basic configuration is a heat pump heat source 1, a hot / cold water air conditioner 2, and a refrigeration cycle in which a compressor, an air heat exchanger, an expansion device, and a water heat exchanger (for example, a plate heat exchanger) are sequentially connected via a refrigerant pipe. It is comprised from the circulation pump 3 and the circulation water path formation means 4 (for example, piping) for connecting these.

  In this hot / cold water air conditioning system, a control device 7 is installed, and the heat pump is based on the air conditioning temperature set by the user, the actual air conditioning temperature, and the circulating water temperature detected by a temperature sensor provided on the water circuit. The compressor driving of the heat source 1 and the driving of the circulation pump 3 are controlled.

  An outgoing water temperature sensor 5 is provided at the outlet of the water circuit connected to the heat pump heat source 1, and measures the temperature of hot water or cold water supplied to the hot / cold water air conditioner 2 (hereinafter referred to as outgoing water temperature). A return water temperature sensor 6 is provided at the inlet of the water circuit connected to the heat pump heat source 1, and measures the temperature of hot water or cold water returning to the heat pump heat source 1 (hereinafter referred to as return water temperature).

  The control device 7 has a function of controlling the operation ON / OFF operation of the heat pump heat source 1 and the compressor operation frequency based on the measurement information from the forward water temperature sensor 5 and the return water temperature sensor 6.

  Here, the heat pump heat source 1 will be described with reference to FIG. FIG. 2 is a diagram illustrating a configuration example of the heat pump heat source 1. The heat pump heat source 1 includes a compressor 103, a four-way valve 104, a water heat exchanger 102, a first expansion valve 106, an intermediate pressure receiver 105, a second expansion valve 107, and an air heat exchanger 101. The circuit is configured.

  The compressor 103 includes an inverter device and the like, and by arbitrarily changing the driving operation frequency, the capacity for sucking and compressing the refrigerant in the compressor and changing it is finely changed. The four-way valve 104 can switch the suction side and the discharge side of the compressor with respect to the pipe connection relationship in the refrigerant circuit, and switches the refrigerant circulation direction in the hot water generation operation and the cold water generation operation in the water heat exchanger.

  The water heat exchanger 102 performs heat exchange between the water flowing through the circulation channel and the refrigerant flowing through the refrigerant circuit. The water heat exchanger 102 heats water flowing through the circulation channel as a radiator (condenser) during hot water heating operation, and becomes a heat absorber (evaporator) that absorbs heat from water in the circulation channel during cold water cooling operation. Cool down. In the present embodiment, the water heat exchanger 102 is built in the heat pump heat source 1, but may be provided independently, for example.

  The first expansion valve 106 adjusts the flow rate of the refrigerant, and performs, for example, pressure adjustment (decompression) of the refrigerant flowing through the water heat exchanger 102. The intermediate pressure receiver 105 is located between the first expansion valve 106 and the second expansion valve 107 of the refrigerant circuit and accumulates excess refrigerant. Here, the suction pipe connected to the suction side of the compressor 103 passes through the inside of the intermediate pressure receiver 105, and the heat of the refrigerant passing through the suction pipe and the refrigerant in the intermediate pressure receiver 105. Exchanges can be made. For this reason, the intermediate pressure receiver 105 has a function as an internal heat exchanger. The second expansion valve 107 adjusts the flow rate of the refrigerant to adjust the pressure. These expansion valves are electronic expansion valves whose opening degree can be changed based on an instruction from the control device. The air heat exchanger 101 is, for example, a fin-and-tube heat exchanger that performs heat exchange between the refrigerant and outside air sent by a blower. During the hot water heating operation, an endothermic action (evaporator) is performed, and during the cold water cooling operation, a heat dissipation action (condenser) is performed.

  Here, as the refrigerant flowing through the refrigerant circuit that the heat pump heat source 1 constitutes, for example, R410A or R407C, which is an HFC mixed refrigerant, R32, which is an HFC single refrigerant having a low global warming potential, and hydrofluoro Olefin-based refrigerants (HFO1234yf, HFO1234ze, etc.), HC-based R290 (propane) or R1270 (propylene) single or mixed refrigerants are used.

  Next, a water cycle in hot water heating in the hot / cold water air conditioning system will be described. During operation of the hot / cold water air conditioning system driven by the heat pump heat source 1, the circulating water is circulated in the water circuit by the circulation pump 3 rotating at a constant speed. Circulating water discharged from the circulation pump 3 flows into the heat pump heat source 1, where it is heated while passing through the water heat exchanger 102 provided therein. The heated circulating water is supplied to the hot / cold water air conditioner 2 and radiated to the space where the hot / cold water air conditioner 2 is installed. Then, the hot water whose temperature has been reduced due to heat dissipation is again sucked into the circulation pump and circulated.

  For the cold water cooling operation, the movement of heat is reversed with respect to the hot water heating (specifically, the circulating water is cooled by the heat pump heat source 1 and is absorbed from the space where the hot / cold water air conditioner 2 is installed). The mechanism of water flowing through the circulation channel is the same.

  The hot water heating operation in this hot / cold water air conditioning system will be described with reference to FIG. FIG. 3 is a flowchart showing the control operation of the hot water heating operation or the cold water cooling operation of the hot / cold water air conditioning system.

First, the hot water heating operation starts from the going water temperature control. (Step S1)
In the forward water temperature control, the controller 7 compares the forward water temperature detection temperature Tm (out) detected by the forward water temperature sensor 5 with the target forward water temperature Tt (out), and the operation ON / OFF operation of the heat pump heat source 1 (thermo ON). / OFF) and the compressor operating frequency.

  The target outgoing water temperature Tt (out) is a value set by the user with a remote controller, for example. If the outgoing water temperature detection temperature Tm (out) detected by the outgoing water temperature sensor 5 is equal to or lower than the target outgoing water temperature Tt (out), the thermostat is turned on and the compressor is operated, while the target outgoing water temperature Tt (out) + α ( For example, if α = 2 deg) or more, the thermo is turned off and the compressor is stopped.

  During operation based on this forward water temperature control, a judgment is made to shift to return water temperature control. The contents will be described below.

  First, in step S2, it is determined whether the compressor operating frequency of the heat pump heat source 1 is the minimum frequency (for example, 25 Hz). If the compressor operating frequency at that time is not the minimum frequency, the process proceeds to step S3, the determination count number Ncount for determining the shift to the return water temperature control is reset, the process returns to step S1, and the forward water temperature control is continued. If the compressor operating frequency is the minimum frequency, the process proceeds to step S4.

  Subsequently, in step S4, it is determined whether or not the thermo is turned off within a predetermined time TA after the thermo is turned on. If the thermo is not turned off within the predetermined time TA after the thermo is turned on, the process proceeds to step S3, the determination count number Ncount for judging the shift to the return water temperature control is reset to zero, and the process returns to step S1 again, and the forward water temperature control is performed. Continue. If the thermo is turned off within a predetermined time after the thermo is turned on, the process proceeds to step S5. That is, it is a state where the required heat amount on the load side is smaller than the operation capability of the minimum frequency.

  In step S5, it is determined whether the thermo is turned on within a predetermined time TB after the thermo is turned off in step S4. If the thermo is not turned on within the predetermined time TB after the thermo is turned off, the process proceeds to step S3, the determination count number for judging the shift to the return water temperature control is reset, the process returns to step S1 again, and the outgoing water temperature control is continued. . If the thermo is turned on within a predetermined time TB after the thermo is turned off, the process proceeds to step S6.

  In Step 6, 1 is added to the determination count number Ncount for determining the shift to the return water temperature control, and the process proceeds to Step S7.

  In step S7, it is determined whether or not the determination count number Ncount for determining to shift to the return water temperature control counted in step S6 is equal to or greater than a predetermined number. If the determination count number Ncount for determining the transition to the return water temperature control is less than the predetermined number, the process returns to step S1 again, and the forward water temperature control is continued. If the determination count number of the determination of transition to the return water temperature control is equal to or greater than a certain number (for example, 3 times), the process proceeds to step S8 and the return water temperature control is performed.

  Steps S2 to S7 described above are transition determinations to return water temperature control during operation of the forward water temperature control.

  When the forward water temperature detection temperature Tm (out) detected by the forward water temperature sensor 5 does not reach the target forward water temperature Tt (out) and the difference is large, the control device 7 increases the operating frequency of the compressor to increase the supply heat amount. Thereby, if the capability of the heat pump heat source 1 becomes larger than the heat radiation amount of the hot / cold water air conditioner 2, the outgoing water temperature detection temperature Tm (out) by the outgoing water temperature sensor 5 increases. When the outgoing water temperature detection temperature Tm (out) reaches the target outgoing water temperature Tt (out), the controller 7 maintains the supply capacity of the heat pump heat source 1 and the hot / cold water air conditioner 2 in order to maintain the temperature. The operating frequency of the compressor is gradually lowered so that the amount of heat is balanced. At this time, even if the compressor operating frequency becomes the minimum frequency (for example, 25 Hz), if the outgoing water temperature detection temperature Tm (out) by the outgoing water temperature sensor 5 continues to rise and becomes thermo OFF, the minimum frequency operation of the heat pump heat source 1 is performed. It can be considered that the minimum capacity at is larger than the heat radiation amount of the hot / cold water air conditioner 2.

  When the compressor is stopped due to the thermo OFF, the supply capacity of the heat pump heat source 1 becomes zero. Therefore, the detection temperature Tm (out) of the outbound water temperature detected by the outbound water temperature sensor 5 becomes equal to or lower than the target outbound water temperature Tt (out) again. To do. However, since the minimum capacity of the heat pump heat source 1 is larger than the heat radiation amount of the hot / cold water air conditioner 2 even if the thermo is turned on, the thermo is turned off again.

  That is, when the minimum capacity of the heat pump heat source 1 is larger than the heat radiation amount of the hot / cold water air conditioner 2, the thermo ON (compressor minimum frequency operation) → the thermo OFF (compressor stop) → the thermo ON (compressor minimum frequency operation). → Thermo-OFF (compressor stop) → ... repeats the ON / OFF cycle operation, so it is determined in steps S2 to S7 whether this ON / OFF cycle operation has been performed within a certain time. .

  In step S8, the hot water heating operation is switched from the forward water temperature control to the return water temperature control.

  In the return water temperature control, the control device 7 compares the return water temperature detection temperature Tm (in) detected by the return water temperature sensor 6 with the target return water temperature Tt (in), and the operation ON / OFF operation of the heat pump heat source 1 (thermo ON). / OFF) and the compressor operating frequency. The target return water temperature Tt (in) is a value calculated by the control device 7 so that the thermo-OFF is not performed when the return water temperature control is shifted to the return water temperature control (for example, the forward water temperature before the return water temperature control is transferred). The maximum temperature detected by the return water temperature sensor 6 during the control operation). If the return water temperature detection temperature Tm (in) detected by the return water temperature sensor 6 is equal to or lower than the target return water temperature Tt (in), the thermostat is turned on and the compressor is operated, and the return water temperature detection temperature Tm (in) is the target return. If the water temperature is Tt (in) + β (for example, β = 2 deg) or more, the thermo is turned off.

  Further, in order to prevent the high temperature water exceeding the allowable upper limit temperature from flowing into the hot / cold water air conditioner 2 due to the high temperature of the outgoing water, the controller 7 detects the outgoing water temperature detected by the outgoing water temperature sensor 5. The relationship between the detected temperature Tm (out) and the outgoing water temperature upper limit Tx (out) is also used for the thermo ON / OFF determination. The outgoing water temperature upper limit value Tx (out) is a value set by the user using a remote controller or the like according to the allowable upper limit temperature of the hot / cold water air conditioner 2, for example. If the outgoing water temperature detection temperature Tm (out) detected by the outgoing water temperature sensor 5 is equal to or less than [the outgoing water temperature upper limit value Tx (out) −γ], the thermo-ON can be performed, and the outgoing water temperature detection temperature Tm (out) is the outgoing water temperature. If it is equal to or greater than the upper limit value Tx (out), the thermo is not turned on. Here, the relationship between β and γ described above is β <γ.

  During the operation based on the return water temperature control, a transition determination (return determination) to the forward water temperature control is performed.

  In step S9, it is determined whether or not the compressor of the heat pump heat source 1 is continuously operated for a certain period of time at a frequency greater than the minimum operating frequency (for example, if the minimum operating frequency is 25 Hz, it is continuously operated for 26 hours or more). If the compressor operating frequency is minimum, the process returns to step S8 again, and the operation is continued by the return water temperature control.

  If the compressor is continuously operated at a frequency higher than the minimum operating frequency for a certain period of time (for example, 60 minutes), the minimum supply capability of the heat pump heat source 1 can be considered to be equal to or less than the heat radiation amount of the hot / cold water air conditioner 2, and the process proceeds to step S3. Then, the determination count number for determining the shift to the return water temperature control is reset, the process returns to step S1, and the operation returns to the operation of the forward water temperature control.

  The flowchart of FIG. 3 also shows the operation for the cold water cooling operation. Since the heat movement in the refrigeration cycle of the heat pump heat source 1 is reversed with respect to the hot water heating, the thermo ON / OFF determination condition (the magnitude of the detected value and the target value is small or large). ) Is different, but the other way of thinking is the same.

  Here, FIG. 4 shows the operating state of the conventional hot water heating equipment when the minimum supply capacity of the heat pump heat source 1 is larger than the hot / cold water air conditioning equipment 2, and FIG. 5 shows the operating state according to the present embodiment. As shown in FIG. 4, in the operation of the conventional hot water heater, only the forward water temperature control is performed, and the response of the forward water temperature detection temperature by the forward water temperature sensor 5 is fast. The detected water temperature exceeds the target water temperature and the thermo is turned off (the compressor operation of the heat pump heat source 1 is stopped), and shortly thereafter (the compressor is stopped, but the circulating pump 3 of the water circuit is driven and the circulating water is (Because it is flowing) The detected water temperature is below the target water temperature and the thermo is on. That is, the thermo ON / OFF cycle operation is performed, and the compressor of the heat pump heat source 1 performs the ON / OFF operation.

  On the other hand, as shown in FIG. 5, in the present embodiment, the ON / OFF cycle operation is detected and determined, and the return water temperature control operation is switched to the return water temperature control operation. Therefore, the return water temperature detected by the return water temperature sensor 6 Since the detected temperature Tm (in) is used, the response is slower than the outgoing water temperature, and since there is heat radiation in the hot / cold water air conditioner 2, the return water temperature detected temperature Tm (in) detected by the return water temperature sensor 6 is for a while. Since the target return water temperature Tt (in) is not exceeded, the thermo-ON state can be continued.

  As described above, in the hot / cold water air conditioning system of the first embodiment, when it is detected that the minimum supply capacity of the heat pump heat source 1 exceeds the amount of heat dissipation or heat absorption required by the hot / cold water air conditioner 2, the incoming water temperature control is performed. Switch to return water temperature control. On the other hand, if it detects that the minimum supply capacity of the heat pump heat source 1 is below the amount of heat dissipation or heat absorption required by the hot / cold water air conditioner 2, it switches from return water temperature control to forward water temperature control. Even if the minimum supply capacity by the compressor operating frequency control of the heat pump heat source is larger than the heat dissipation amount in the case of hot water heating or the heat absorption amount in the case of cold water cooling, Since the ON / OFF cycle operation of the compressor of the heat pump heat source by repeating OFF can be suppressed, high efficiency and high To provide a life of hot and cold air conditioning system.

Embodiment 2. FIG.
FIG. 6 is a water circuit diagram showing a hot / cold water air-conditioning system according to Embodiment 2 of the present invention. The second embodiment is different from the first embodiment only in that an auxiliary heater 8 for heating the circulating water is provided between the heat pump heat source 1 and the outgoing water temperature sensor 5. When the supply capacity of the heat pump heat source 1 is insufficient in the hot water heating operation, the circulating water is heated as an auxiliary heat source.

  The operation of the hot water heating operation or the cold water cooling operation in the present embodiment is the same as that of the first embodiment, and the minimum supply capacity of the heat pump heat source 1 exceeds the heat radiation amount or the heat absorption amount required by the hot / cold water air conditioner 2. When it is detected, switching from the forward water temperature control to the return water temperature control is performed. On the other hand, when it is detected that the minimum supply capacity of the heat pump heat source 1 is less than the heat dissipation or heat absorption required by the hot / cold water air conditioner 2, the return water temperature control is started. Since the control device 7 that operates by switching to the outgoing water temperature control is provided, the minimum supply capacity by the compressor operating frequency control of the heat pump heat source is based on the heat dissipation amount in the case of hot water heating of the hot / cold water air conditioner or the heat absorption amount in the case of cold water cooling. Even when it is large, the thermo ON / OFF cycle operation can be suppressed.

Embodiment 3 FIG.
FIG. 7 is a water circuit diagram showing a hot / cold water air-conditioning system according to Embodiment 3 of the present invention. The third embodiment is based on the second embodiment. In the water circuit, a branch point is provided between the outgoing water temperature sensor 5 and the hot / cold water air conditioner 2 and the circulation pump flows out of the hot / cold water air conditioner 2. A hot water storage tank 10 having a built-in heat exchanger 9 connected to the hot / cold water air conditioner 2 in parallel with the circulating water channel forming means 4 and a water temperature in the hot water storage tank 10 is detected. The tank water temperature sensor 11 is different from the tank water temperature sensor 11 in that it has an electric three-way valve 12 for switching a circuit on the hot / cold water air-conditioning appliance 2 side and a circuit on the heat exchanger 9 side to either a branch point or a junction. .

  By operating the electric three-way valve 12 in FIG. 7 and switching the flow of hot water or cold water, a hot water heating operation or a cold water cooling operation and a hot water supply operation to the hot water storage tank 10 can be selected.

  In the present embodiment, the compressor drive control and the forward water temperature control or the return water temperature control of the heat pump heat source 1 in the operation of the hot water heating operation or the cold water cooling operation and the operation of the hot water supply operation are the same as those in the first embodiment. When it is detected that the minimum supply capacity exceeds the amount of heat dissipation or heat absorption required by the hot / cold water air conditioner 2, the return water temperature control is switched to the return water temperature control, while the minimum supply capacity of the heat pump heat source 1 is the hot / cold water air conditioner. 2 is provided with a control device 7 that operates by switching from the return water temperature control to the forward water temperature control when it detects that the heat radiation amount or the heat absorption amount required by the heat pump 2 is lower than the required heat release amount. Even if is greater than the amount of heat released in the case of hot water heating of a hot / cold water air conditioner or the amount of heat absorbed in the case of cold water cooling, / The OFF cycle operation can be suppressed.

  DESCRIPTION OF SYMBOLS 1 Heat pump heat source, 2 hot / cold water air-conditioning equipment, 3 circulation pump, 4 circulation water path formation means, 5 going water temperature sensor, 6 return water temperature sensor, 7 control apparatus, 8 auxiliary heater, 9 heat exchanger, 10 hot water tank, 11 tank water temperature Sensor, 12 Electric three-way valve, 101 Air heat exchanger, 102 Water heat exchanger, 103 Compressor, 104 Four-way valve, 105 Medium pressure receiver, 106 First expansion valve, 107 Second expansion valve.

Claims (5)

In a hot / cold water air conditioning system for forming a water circuit by annularly connecting a heat pump heat source, hot / cold water air conditioner, and circulation pump with piping, supplying hot water or cold water from the heat pump heat source to the hot / cold water air conditioner and performing hot water heating or cold water cooling the hot water or cold water generated by the heat pump heat source provided with a water temperature sensor forward to the outlet of the water circuit for circulating to the hot and cold water air-conditioning device, provided the water temperature sensor back to the inlet of the heat pump heat source side of the water circuit, before Return water temperature detection detected by the return water temperature sensor from the forward water temperature control that controls the heat pump heat source based on the difference between the forward water temperature detection temperature Tm (out) detected by the forward water temperature sensor and the target outgoing water temperature Tt (out). The heat pump heat source is controlled by the difference between the temperature Tm (in) and the target return water temperature Tt (in). Return a control device for switching the temperature control, the control device, the forward water temperature forward is detected by the sensor temperature detection temperature Tm (out) the target forward water temperature Tt (out) following when the compressor of the heat pump heat source The number of determinations based on the thermo-ON / OFF operation for stopping the compressor when the operation water temperature detection temperature Tm (out) is equal to or greater than the predetermined value α from the target water temperature Tt (out). When the determination count number exceeds a predetermined value, it is determined that the minimum supply capacity of the heat pump heat source exceeds the required heat quantity of the hot / cold water air conditioner, and switching from the forward water temperature control to the return water temperature control is performed. A featured hot / cold water air conditioning system. The operation by the thermo ON a predetermined time TA or more, or hot and cold water air-conditioning system of claim 1 Symbol mounting stop of thermo OFF is characterized by resetting the decision count and has passed more than a predetermined time TB. In a hot / cold water air conditioning system in which a water circuit is formed by annularly connecting a heat pump heat source, hot / cold water air conditioner, and circulation pump with piping, and hot water or cold water is supplied from the heat pump heat source to the hot / cold water air conditioner to perform hot water heating or cold water cooling A water temperature sensor is provided at the outlet of the water circuit for circulating hot water or cold water generated by the heat pump heat source to the hot / cold water air conditioner, and a return water temperature sensor is provided at the heat pump heat source side inlet of the water circuit, It is determined that the minimum supply capacity of the heat pump heat source exceeds the necessary heat quantity of the hot / cold water air conditioner, and the difference between the forward water temperature detection temperature Tm (out) detected by the forward water temperature sensor and the target forward water temperature Tt (out) The return water detected by the return water temperature sensor from the outgoing water temperature control that controls the heat pump heat source by A controller that switches to the return water temperature control that controls the heat pump heat source based on the difference between the detected temperature Tm (in) and the target return water temperature Tt (in), and the control device switches from the forward water temperature control to the return water temperature control. A hot / cold water air conditioning system characterized in that, when switching, the target return water temperature Tt (in) is calculated and set from the return water temperature detection temperature in the forward water temperature control before switching. The control device returns to the forward water temperature control if the compressor of the heat pump heat source is continuously operated for a predetermined time or more at an operation frequency higher than a minimum operation frequency during operation by the return water temperature control. The hot / cold water air conditioning system according to any one of claims 1 to 3 . The water circuit has a branch point between the outgoing water temperature sensor and the hot / cold water air conditioner and a junction point between the hot / cold water air conditioner and the circulation pump, and is connected to the hot / cold water air conditioner by a pipe in parallel. A hot water storage tank having a heat exchanger, a tank water temperature sensor for detecting the water temperature in the hot water storage tank, a circuit on the hot / cold water air conditioner side at any one of the branching point or the junction point, and a hot water tank side The hot / cold water air conditioning system according to any one of claims 1 to 4 , further comprising a three-way valve for switching the circuit.

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