JP2021071250A - Heat pump-type hot water heating system - Google Patents

Abstract

To provide a heat pump-type hot water heating system capable of properly heating air while performing defrosting in a normal cycle defrosting.SOLUTION: In a heat pump-type hot water heating system 1 in which a heating operation is performed so that a temperature of a circulation liquid to be supplied to heat exchange terminals 13A-C becomes a target hot water temperature, and a normal cycle defrosting is performed when a prescribed defrosting start condition is established in a heating operation, circulation of the circulation liquid is stopped in starting the normal cycle defrosting, and the circulation liquid is circulated when a prescribed condition is satisfied on the basis of a refrigerant temperature at an outlet side of an air heat exchanger 7, detected by refrigerant temperature detection means 12, while continuing defrosting of an air heat exchanger 7 during the normal cycle defrosting, thus the heating by the heat exchange terminal 13 can be performed by properly circulating the circulation liquid according to the refrigerant temperature at the outlet side of the air heat exchanger 7 while performing defrosting in the normal cycle defrosting.SELECTED DRAWING: Figure 1

Description

The present invention relates to a heat pump type hot water heating system capable of performing hot water heating.

Conventionally, this type of heat pump type heat source machine having a compressor, a liquid refrigerant heat exchanger, an expansion valve, and an air heat exchanger, and a circulation pump for circulating the circulating liquid are provided, and the air heat exchanger is provided during operation. When defrosting, there is a so-called positive cycle defrosting that circulates the refrigerant in the same direction as the flow direction of the refrigerant during operation. There was something to do. (See, for example, Patent Document 1.)

Japanese Unexamined Patent Publication No. 2012-266636

By the way, assuming that this conventional one is applied to a hot water heating system, the circulation pump will continue to be stopped during the normal cycle defrosting. When the circulation pump is stopped, the circulating liquid is not supplied to the heat exchange terminal for heating the room during the normal cycle defrosting, so that the unheated state continues and the feeling of heating may deteriorate. In addition, when the circulation pump is continuously driven so as to have a minute flow rate during the positive cycle defrosting, the heat exchange between the refrigerant and the circulating liquid in the liquid refrigerant heat exchanger causes one of the amount of heat possessed by the refrigerant. The part was absorbed by the circulating fluid side, the amount of heat for defrosting the air heat exchanger was deprived, the defrosting of the air heat exchanger did not proceed, and there was a possibility that the defrosting would not be completed.

In order to solve the above problems, in claim 1, the present invention includes a compressor for compressing a refrigerant, a liquid refrigerant heat exchanger for heat exchange between a circulating liquid and the refrigerant, an expansion valve, and an air heat exchanger. A heat pump type heat source machine, the liquid refrigerant heat exchanger of the heat pump type heat source machine, a heat exchange terminal that heats the air-conditioned space using the circulating liquid as a heat source, and a circulation pump that circulates the circulating liquid. The heat pump type heat source machine and the circulation pump are controlled so that the temperature of the circulating liquid supplied to the heat exchange terminal becomes the target hot water temperature and the circulation circuit formed by connecting with pipes to circulate the circulating liquid. A heat pump type hot water heating system including a control unit for performing a heating operation and a defrost control means for defrosting the air heat exchanger when a predetermined defrosting start condition is satisfied during the heating operation. In the above, a refrigerant temperature detecting means for detecting the refrigerant temperature on the outlet side of the air heat exchanger is provided, and the defrost control means circulates the refrigerant in the same direction as the flow direction of the refrigerant during the heating operation and expands. The opening degree of the valve is expanded to be larger than that during the heating operation to perform positive cycle defrosting to defrost the air heat exchanger, and at the start of the positive cycle defrosting, the circulation of the circulating fluid is stopped. During the normal cycle defrosting, while continuing the defrosting of the air heat exchanger, if it is determined that a predetermined condition has been reached based on the refrigerant temperature detected by the refrigerant temperature detecting means, the circulating fluid is discharged. It was supposed to be circulated.

Further, in claim 2, the defrost control means stops the circulation pump at the start of the positive cycle defrosting, and the refrigerant temperature detected by the refrigerant temperature detecting means during the positive cycle defrosting is determined. When it is determined that the predetermined circulation pump drive start condition that is satisfied before the predetermined defrosting end condition is satisfied is reached, the rotation speed of the circulation pump is set to be lower than that during the heating operation.

Further, in claim 3, the defrosting control means determines that the refrigerant temperature detected by the refrigerant temperature detecting means has reached the predetermined circulation pump drive start condition during the positive cycle defrosting. As the refrigerant temperature detected by the refrigerant temperature detecting means approaches the direction in which the predetermined defrosting end condition is satisfied, the rotation speed of the circulation pump is increased.

According to claim 1 of the present invention, during normal cycle defrosting, while defrosting, the circulating liquid is appropriately circulated according to the temperature of the refrigerant on the outlet side of the air heat exchanger, and the heat exchange terminal is used. It can also be heated.

Further, according to claim 2, the defrosting control means stops the circulation pump at the start of the normal cycle defrosting, and the refrigerant temperature detected by the refrigerant temperature detecting means during the normal cycle defrosting is a predetermined defrosting. When it is determined that the predetermined circulation pump drive start condition that is satisfied before the end condition is satisfied is reached, the circulation pump is driven at a lower rotation speed than during the heating operation, so that the positive cycle defrosting is performed. At the start, since the amount of frost on the air heat exchanger is large, the circulation pump is stopped to drive the circulation pump so that the amount of heat retained by the refrigerant is used only for defrosting, and defrosting is performed intensively. When the refrigerant temperature detected by the refrigerant temperature detecting means reaches the circulation pump drive start condition, the circulation pump is started to be driven at a lower speed than during the heating operation so as not to take too much heat required for defrosting. Therefore, while continuing defrosting, the circulating liquid can be circulated to the heat exchange terminal for heating, and the non-heating time during the defrosting operation can be shortened.

Further, according to claim 3, the defrost control means determines that the refrigerant temperature detected by the refrigerant temperature detecting means has reached a predetermined circulation pump drive start condition during normal cycle defrosting, and then the refrigerant. As the refrigerant temperature detected by the temperature detecting means approaches the direction in which the defrosting end condition is satisfied, the number of rotations of the circulation pump is increased so that the refrigerant temperature detected by the refrigerant temperature detecting means can be increased. When the circulation pump drive start condition is reached and then the defrosting end condition is satisfied, that is, the temperature of the refrigerant on the outlet side of the air heat exchanger rises, and the defrosting of the air heat exchanger is performed. This means that the amount of excess heat other than the required amount of heat is increasing, and in that case, the number of rotations of the circulation pump is increased as the refrigerant temperature detected by the refrigerant temperature detecting means approaches the direction in which the defrosting end condition is satisfied. Therefore, the amount of heat used for heating can be increased, and the decrease in the feeling of heating during the defrosting operation can be suppressed.

The schematic block diagram of the heat pump type hot water heating system of one Embodiment of this invention. The figure which shows the screen display example of a remote controller. The figure which shows the screen display example of a remote controller at the time of a heating operation. Main block diagram. The figure explaining the operation at the time of a heating operation. The flowchart which shows the control procedure at the time of a heat storage operation. A flowchart showing a control procedure for setting a heat storage target temperature. A flowchart showing another control procedure for setting a heat storage target temperature. A flowchart showing still another control procedure for setting the heat storage target temperature. Table data showing the correspondence between the measurement time t and the correction value α used for correcting the heat storage operation start condition. The flowchart which shows the control procedure for correcting the heat storage operation start condition. Table data showing the correspondence between the refrigerant temperature r and the circulation pump rotation speed used for controlling the circulation pump rotation speed during the defrosting operation. The flowchart which shows the control procedure at the time of defrosting operation.

Next, the configuration of the heat pump type hot water heating system 1 according to the embodiment of the present invention will be described in detail with reference to the drawings.

Reference numeral 2 denotes a heat pump unit as a heat pump type heat source machine for supplying the heated circulating fluid. The heat pump unit 2 is a compressor 3 having a variable rotation speed for compressing the refrigerant in the housing, and heat exchange between the refrigerant and the circulating fluid. It has a liquid refrigerant heat exchanger 4, an expansion valve 5 as a depressurizing means for reducing the pressure of the refrigerant, and an air heat exchanger 7 for exchanging heat with the air (outside air) sent by the operation of the blower fan 6. The heat pump circuit 9 is formed by connecting the refrigerant pipes 8 in an annular shape to circulate the refrigerant. As the refrigerant that circulates in the heat pump circuit 9, any refrigerant such as an HFC refrigerant or a carbon dioxide refrigerant can be used. The liquid refrigerant heat exchanger 4 is composed of, for example, a plate type heat exchanger. In the plate type heat exchanger, a plurality of heat transfer plates are laminated, and a refrigerant flow path through which a refrigerant flows and a liquid through which a circulating liquid flows. The flow paths are formed alternately with each heat transfer plate as a boundary.

10 is a discharge temperature sensor as a discharge temperature detecting means for detecting the discharge temperature of the refrigerant discharged from the compressor 3, 11 is an outside air temperature sensor for detecting the outside air temperature, and 12 is an air heat exchanger 7 to the compressor 3. A refrigerant temperature sensor provided in the refrigerant pipe 8 as a refrigerant temperature detecting means for detecting the temperature of the refrigerant on the outlet side of the air heat exchanger 7.

13 is connected to the heat pump unit 2 via an forward pipe 14 and a return pipe 15 as pipes, and the circulating liquid heated by the heat pump unit 2 is supplied, and the supplied circulating liquid is used as a heat source to heat the air-conditioned space. It is a heat exchange terminal. As the heat exchange terminal 13, a radiant terminal such as a floor heating panel, a radiant panel, or a radiator can be used. Although three heat exchange terminals 13A, 13B, and 13C are provided in FIG. 1, the number of heat exchange terminals 13 may be one, two, or a plurality of three or more.

Here, one forward header 16 is provided in the middle of the forward pipe 14 extending from the liquid refrigerant heat exchanger 4 of the heat pump unit 2 toward the heat exchange terminal 13, and the forward header 16 of the forward pipe 14 is provided. The upstream portion is configured as one common going pipe 14a, and is a circulating fluid (for example, water, antifreeze, etc., which is heated by the liquid refrigerant heat exchanger 4 of the heat pump unit 2 and is hereinafter heated. Is appropriately expressed as hot water) is supplied. Then, in the portion of the outgoing pipe 14 on the downstream side of the outgoing header 16, individual outgoing pipes 14b are branched by the number of heat exchange terminals 13 (three in the illustrated example). Thermal valves 17 (17A, 17B, 17C) as flow rate control valves are attached to the branched individual outbound pipes 14b, respectively.

Similarly, one return header 18 is provided in the middle of the return pipe 15 extending from the heat exchange terminal 13 toward the liquid refrigerant heat exchanger 4 of the heat pump unit 2. In the upstream portion, individual return pipes 15b are branched by the number of heat exchange terminals 13 (three in the illustrated example). The portion of the return pipe 15 on the downstream side of the return header 18 is configured as one common return pipe 15a, and the circulating liquid introduced via the individual return pipes 15b is transferred to the liquid refrigerant heat exchanger 4 of the heat pump unit 2. And return.

The forward header 16 and the return header 18 may be provided inside the housing of the heat pump unit 2 as shown in the drawing, or may be provided outside the heat pump unit 2 housing.

Reference numeral 19 denotes a circulation circuit formed by connecting the liquid refrigerant heat exchanger 4 of the heat pump unit 2 and the heat exchange terminal 13 with the forward pipe 14 and the return pipe 15 to circulate the circulating liquid. The circulation circuit 19 includes a circulation pump 20 having a variable rotation speed for circulating the circulation liquid, and a systurn 21 for storing the circulation liquid and adjusting the pressure of the circulation circuit 19. Each of the individual return pipes 15b of the return pipe 15 has a return temperature sensor 22 (22A, 22B) as a temperature detecting means for detecting the temperature of the circulating liquid flowing into the liquid flow path of the liquid refrigerant heat exchanger 4. , 22C) is provided.

Reference numeral 23 denotes a remote controller installed on an indoor wall surface such as a living room. The remote controller 23 includes a display unit 24, an operation / stop switch 25 for instructing operation start / stop of the heat exchange terminal 13 as an operation switch, and heat exchange. A timer switch 26 for instructing the terminal 13 to operate with a timer, an operation changeover switch 27 for instructing the switching of the operation mode (normal mode, save mode, etc.) of the heat exchange terminal 13, and the screen display immediately before. A return switch 28 for returning to the screen, a menu / decision switch 29, and a cross key 30 in the up / down / left / right directions are provided. The remote controller 23 has a built-in CPU as a control means for performing various displays, a memory as a storage means, and the like, and transmits information by bidirectional communication with the control unit 31 described later. be able to. The remote controller 23 has a function of setting the temperature level (hot water temperature) of the circulating fluid supplied to the heat exchange terminal 13, and in the present embodiment, the temperature levels 1 to 9 can be set.

Here, the display of the remote controller 23 will be described with reference to FIG. 2. The display unit 24 can display a plurality of setting screens (screens 100 to 101) in a switchable manner under the control of the CPU. That is, in the example shown in FIG. 2A, the display unit 24 displays the overall setting screen 100 for making settings related to the entire heat pump type hot water heating system 1. When the overall setting screen 100 is displayed on the display unit 24, the operating state of the heat pump unit 2 (heat source) is displayed in the center of the overall setting screen 100 (stopped in this example), and the heat pump unit 2 is in the main tab TM. A status display indicating the operating status of is displayed (in this example, "OFF", which is a stopped status, is displayed).

On the other hand, in the example shown in FIG. 2B, the display unit 24 displays the terminal setting screen 101 for making the settings related to the heat exchange terminal 13, including the operation start / stop setting of the heat exchange terminal 13. .. The terminal setting screen 101 can be provided as many as the number corresponding to the number of heat exchange terminals 13 to be connected (three in this embodiment). When the terminal setting screen 101 is displayed on the display unit 24, the room name and operating state of the corresponding heat exchange terminal 13 are displayed in the center of the terminal setting screen 101, and the heat exchange terminal 13 is supplied to the right side of the screen. The temperature level of the hot water and the indicator showing the temperature level are displayed. In this example, the terminal setting screen 101 of the heat exchange terminal 13A corresponding to room A is displayed as the air-conditioned space, the hot water heating in room A is stopped in the center of the screen, and the temperature level of hot water is on the right side of the screen. It is displayed that it is set to 5. In the tab TA, a state display (“OFF” notation) indicating the operating state of the heat exchange terminal 13A corresponding to the room A is made. Although detailed description is omitted, the contents displayed on the terminal setting screen 101 of the heat exchange terminal 13B corresponding to room B and the terminal setting screen 101 of the heat exchange terminal 13C corresponding to room C correspond to the above room A. This is the same as the content displayed on the terminal setting screen 101 of the heat exchange terminal 13A.

In the present embodiment, one remote controller 23 can be used to set the operation of the three heat exchange terminals 13A, 13B, and 13C. However, the remote controller 23 is provided for each heat exchange terminal 13, and one remote controller 23 can be used. It may be such that the operation setting of one heat exchange terminal 13 can be performed.

Reference numeral 31 denotes a control unit including a storage means for storing various data and programs and a control means for performing calculation / control processing. The control unit 31 is a signal from various sensors in the heat pump unit 2 and a signal from the remote control 23. In response to this, the compressor 3, the expansion valve 5, the blower fan 6, the thermal valve 17, and the circulation pump 20 are controlled to be driven so that the temperature of the hot water supplied to the heat exchange terminal 13 becomes the target hot water temperature. In addition, the heat pump unit 2 (compressor 3, expansion valve 5, blower fan 6), thermal valve 17, and circulation pump 20 are controlled to perform heating operation.

As shown in FIG. 4, the control unit 31 includes a compressor control means 32 that controls the rotation speed of the compressor 3, an expansion valve control means 33 that controls the opening degree of the expansion valve 5, and a rotation speed of the circulation pump 20. The circulation pump control means 34 for controlling the above, the target hot water temperature setting means 35 for setting the target hot water temperature of the circulating liquid supplied to the heat exchange terminal 13, and the target discharge temperature of the refrigerant discharged from the compressor 3 are set. It has a target discharge temperature setting means 36. The details of the control / processing contents of each of the above means will be described later.

Further, the control unit 31 raises the temperature of the circulating liquid supplied to the heat exchange terminal 13 during operation to a higher heat storage target temperature than before when a predetermined heat storage operation start condition is satisfied during the heating operation. The heat storage control means 37 is provided with a heat storage control means 37 for performing a heat storage operation and a defrost control means 38 for performing a defrost operation for melting the frost of the air heat exchanger 7, and the heat storage control means 37 is a time from the start of the heat storage operation. The counting means 39 for counting the heat storage operation, the measuring means 40 for measuring the time from when the temperature of the circulating fluid reaches the heat storage target temperature during the heat storage operation until the predetermined defrosting start condition is satisfied, and the status of the heat storage operation this time. It has a heat storage start condition correction means 41 that corrects the next heat storage operation start condition based on the above. The details of the control / processing contents of each of the above means will be described later.

Next, the operation of the heat pump type hot water heating system 1 during the heating operation will be described with reference to the drawings. Here, a scene in which the heating operation is performed by the heat exchange terminal 13A will be described.

First, when the operation / stop switch 25 of the remote controller 23 is operated by the user while the terminal setting screen 101 is displayed on the display unit 24 of the remote controller 23, and an instruction to start the heating operation of the heat exchange terminal 13A is given, the control unit At 31, the instruction signal is received. At this time, as shown in FIG. 3B, the operating state (A room temperature water heating operation) and the temperature level (level 5) are displayed on the display unit 24 of the remote controller 23, and the inside of the tab TA is displayed. It becomes "ON" notation. On the overall setting screen 100, as shown in FIG. 3A, the operating state (during operation) of the heat pump unit 2 is displayed in the center of the screen, and the tab TM is indicated as “ON”.

When the instruction to start the heating operation is issued, the control unit 31 starts the operation of the heat pump circuit 9 (starts driving the compressor 3 and the blower fan 6 and controls the expansion valve 5 to a predetermined opening degree), and further. The control unit 31 opens the thermal valve 17A corresponding to the heat exchange terminal 13A and starts driving the circulation pump 20, so that the heating operation is started. During the heating operation, in the heat pump circuit 9, a high-temperature, high-pressure gaseous refrigerant compressed by the compressor 3 is discharged from the compressor 3, and the refrigerant is circulated in the liquid refrigerant heat exchanger 4 functioning as a condenser. It exchanges heat with the hot water flowing through the circuit 19, releases heat to the hot water, and changes to a high-pressure refrigerant in a gas-liquid mixed state while heating. Then, the refrigerant in this state is decompressed by the expansion valve 5 to become a low-pressure refrigerant and easily evaporates, and in the air heat exchanger 7 functioning as an evaporator, the outside air and heat blown by the drive of the blower fan 6 It is exchanged, absorbs heat from the outside air, becomes a low-temperature, low-pressure gaseous refrigerant, and returns to the compressor 3 again. (Refer to the flow of the refrigerant indicated by the arrow in FIG. 5).

On the other hand, in the circulation circuit 19, the hot water flowing into the liquid refrigerant heat exchanger 4 by the drive of the circulation pump 20 driven at a constant rotation speed is heat exchanged with the refrigerant in the liquid refrigerant heat exchanger 4 functioning as a condenser. The heated and heated hot water is then supplied to the heat exchange terminal 13A and used for heating the air-conditioned space (room A) corresponding to the heat exchange terminal 13A, and is dissipated by the heat exchange terminal 13A to lower the temperature. The hot water is returned to the liquid refrigerant heat exchanger 4 and heated. Here, since the heating by the heat exchange terminal 13B and the heat exchange terminal 13C is stopped, the heat valve 17B corresponding to the heat exchange terminal 13B and the heat valve 17C corresponding to the heat exchange terminal 13C are closed. As shown in FIG. 5, the hot water heated by the liquid refrigerant heat exchanger 4 is circulated only to the heat exchange terminal 13A. (See the flow of hot water indicated by the arrow in Fig. 5.)

During the heating operation, the target hot water temperature of the hot water supplied to the heat exchange terminal 13A is set by the target hot water temperature setting means 35. The target hot water temperature setting means 35 sets the corresponding target hot water temperature according to the temperature level set by the remote controller 23. In the present embodiment, the target hot water temperature setting means 35 has a target return temperature (for example, hot water temperature associated with the temperature level-predetermined temperature) as the corresponding target hot water temperature according to the temperature level set by the remote controller 23. Is set. The compressor control means 32 controls the rotation speed of the compressor 3 so that the temperature of the hot water detected by the return temperature sensor 22A becomes the target return temperature set by the target hot water temperature setting means 35. Therefore, the temperature of the hot water supplied to the heat exchange terminal 13A is set to the temperature level set by the remote control 23. Here, when the hot water temperature detected by the return temperature sensor 22A reaches the target return temperature, it is determined that the temperature of the hot water supplied to the heat exchange terminal 13A has reached the temperature level set by the remote controller 23. To.

Explaining the rotation speed control of the compressor 3 in more detail, the compressor control means 32 has a temperature difference between the hot water temperature detected by the return temperature sensor 22A and the target return temperature set by the target hot water temperature setting means 35. The magnitude of the load is determined from the above, and the number of revolutions of the compressor 3 is increased or decreased according to the magnitude of the load. The hot water temperature detected by the return temperature sensor 22A has not reached the target return temperature. In this case, the number of revolutions of the compressor 3 is increased. On the other hand, when the hot water temperature detected by the return temperature sensor 22A reaches the target return temperature, the number of revolutions of the compressor 3 is reduced in order to maintain the hot water temperature detected by the return temperature sensor 22A at the target return temperature. It is a thing.

In the present embodiment, the target hot water temperature setting means 35 sets the target return temperature as the corresponding target hot water temperature according to the temperature level set by the remote control 23, and sets the target return temperature as the corresponding target hot water temperature on the inlet side of the liquid refrigerant heat exchanger 4. The so-called return temperature control is performed by controlling the rotation speed of the compressor 3 so that the temperature of the hot water detected by the return temperature sensor 22 provided on the return pipe 15 (on the inflow side) reaches the target return temperature. Not limited to this, the target hot water temperature setting means 35 sets the hot water temperature corresponding to the temperature level set by the remote control 23 as the target hot water temperature (target going temperature) as it is, and sets the outlet side of the liquid refrigerant heat exchanger 4 as it is. A forward temperature sensor (not shown) is provided as a temperature detecting means on the forward pipe 14 (outflow side), and the rotation speed of the compressor 3 is set so that the temperature of the hot water detected by the forward temperature sensor becomes the target forward temperature. It may be controlled, that is, so-called forward temperature control is performed.

Further, during the heating operation, the target discharge temperature of the refrigerant discharged from the compressor 3 is set by the target discharge temperature setting means 36. The target discharge temperature setting means 36 sets the corresponding target discharge temperature based on the target hot water temperature set by the target hot water temperature setting means 35. More specifically, the target discharge temperature setting means 36 is detected by the coefficient relating to the rotation speed of the compressor 3 during the heating operation and the outside air temperature sensor 11 in addition to the target hot water temperature set by the target hot water temperature setting means 35. The corresponding target discharge temperature (= target hot water temperature + coefficient related to the rotation speed of the compressor 3 + coefficient related to the outside air temperature) is set based on the coefficient related to the outside air temperature during the heating operation. The expansion valve control means 33 has an expansion valve 5 so that the temperature of the refrigerant discharged from the compressor 3 detected by the discharge temperature sensor 10 becomes the target discharge temperature set by the target discharge temperature setting means 36. The opening degree of is controlled.

Explaining the opening degree control of the expansion valve 5 in more detail, the expansion valve control means 33 is a temperature between the temperature of the refrigerant detected by the discharge temperature sensor 10 and the target discharge temperature set by the target discharge temperature setting means 36. The opening degree of the expansion valve 5 is controlled according to the difference, and when the temperature of the refrigerant detected by the discharge temperature sensor 10 does not reach the target discharge temperature, the opening degree of the expansion valve 5 is narrowed ( Control in the closing direction). On the other hand, when the temperature of the refrigerant detected by the discharge temperature sensor 10 reaches the target discharge temperature, the opening degree of the expansion valve 5 is increased in order to maintain the temperature of the refrigerant detected by the discharge temperature sensor 10 at the target discharge temperature. It controls the opening direction.

Further, during the heating operation, the circulation pump 20 is controlled to a constant rotation speed (for example, 3500 rpm) by the circulation pump control means 34.

Next, the heat storage operation, which is a characteristic operation performed during the heating operation, will be described, and here, the heating operation by the heat exchange terminal 13A will be described. The heat storage operation raises the temperature of the circulating liquid supplied to the heat exchange terminal 13A when a predetermined heat storage operation start condition is satisfied during the heating operation. The heat storage operation start condition is set based on the outside air temperature and the refrigerant temperature on the outlet side of the air heat exchanger 7, that is, from the outside air temperature and the refrigerant temperature on the outlet side of the air heat exchanger 7. , It is a condition that the defrosting operation is presumed to be started soon (a condition that is satisfied before the defrosting start condition is satisfied).

During the heating operation, the heat storage control means 37 determines whether or not the heat storage operation start condition is satisfied, and if it is determined that the heat storage operation start condition is satisfied, the heat storage operation is started. At the same time as the start of this heat storage operation, the counting of the counting means 39 is also started. When the heat storage operation is started, the heat storage control means 37 outputs a signal indicating that the heat storage operation is in progress, and the target hot water temperature setting means 35 receives the signal and returns to the target during the heating operation that has been set up to that point. A predetermined heat storage target temperature higher than the temperature (target hot water temperature) is set as a new target return temperature (target hot water temperature).

At this time, the compressor control means 32 adjusts the rotation speed of the compressor 3 so that the temperature of the hot water detected by the return temperature sensor 22A becomes the heat storage target temperature set by the target hot water temperature setting means 35. It is controlled, and as an actual movement, immediately after the start of the heat storage operation, the target return temperature (target hot water temperature) is changed to the heat storage target temperature, which is higher than the target return temperature during the heating operation that had been set up to that point. Therefore, the temperature difference between the hot water temperature detected by the return temperature sensor 22A and the target return temperature (heat storage target temperature) is larger than that during the heating operation immediately before the heat storage operation. The rotation speed of the compressor 3 is increased. Then, when the hot water temperature detected by the return temperature sensor 22A reaches the target return temperature (heat storage target temperature), the compressor 3 is used to maintain the hot water temperature detected by the return temperature sensor 22A at the target return temperature. Try to reduce the number of revolutions.

Further, when the heat storage operation is started, a signal indicating that the heat storage operation is in progress is output from the heat storage control means 37 to the target discharge temperature setting means 36, and when the target discharge temperature setting means 36 receives the signal, the heat storage operation 36 receives the signal. It is controlled to maintain the target discharge temperature set at the time of the heating operation immediately before the start of the operation. That is, during the heat storage operation, unlike the heating operation, the target discharge temperature is not changed according to the target return temperature (target hot water temperature), and the target return temperature is higher than that during the heating operation. Even if the temperature is changed to the target temperature, the target discharge temperature set at the time of the heating operation immediately before the start of the heat storage operation is maintained as it is, and the target discharge temperature is maintained until the heat storage operation is completed.

At this time, since the target discharge temperature is maintained as it is set during the heating operation immediately before the start of the heat storage operation, the expansion valve control means 33 does not significantly change the opening degree of the expansion valve 5. Immediately after the start of the heat storage operation, the opening during the heating operation immediately before the start of the heat storage operation is maintained. During the heat storage operation, the temperature of the refrigerant discharged from the compressor 3 is slightly higher or lower, but the target discharge temperature is not higher than that during the heating operation immediately before the start of the heat storage operation. The operation of squeezing (closing) the air heat exchanger 7 does not occur, and the temperature of the refrigerant circulated in the air heat exchanger 7 does not drop significantly.

Further, when the heat storage operation is started, a signal indicating that the heat storage operation is in progress is output from the heat storage control means 37 to the circulation pump control means 34, and when the circulation pump control means 34 receives the signal, the circulation pump control The means 34 controls the rotation speed of the circulation pump 20 to be lower than that during the heating operation.

Here, assuming that the temperature of the hot water flowing into the liquid refrigerant heat exchanger 4 is constant and a constant amount of heat is given to the hot water from the refrigerant in the liquid refrigerant heat exchanger 4, the rotation speed of the circulation pump 20 is reduced. In this case, the circulating flow rate of the hot water per unit time decreases and the temperature efficiency increases, so that the temperature of the hot water flowing out from the liquid refrigerant heat exchanger 4 becomes higher. Therefore, if the rotation speed of the circulation pump 20 is lowered during the heat storage operation, the temperature of the hot water supplied to the heat exchange terminal 13A can be raised. Further, since the target hot water temperature during the heat storage operation is set to a heat storage target temperature higher than the target hot water temperature during the heating operation, the rotation speed of the compressor 3 is controlled to increase. As a result, the circulating flow rate of the refrigerant passing through the liquid refrigerant heat exchanger 4 increases, and the amount of heat to be given from the refrigerant to the hot water in the liquid refrigerant heat exchanger 4 increases, so that the liquid refrigerant heat exchanger 4 flows out. It becomes easy to raise the temperature of hot water. Further, since the rotation speed of the circulation pump 20 is lower than that during the heating operation, the amount of heat given to the hot water from the refrigerant in the liquid refrigerant heat exchanger 4 is reduced, and the temperature of the refrigerant flowing out from the liquid refrigerant heat exchanger 4 is high. Become. Then, the temperature of the refrigerant circulated to the air heat exchanger 7 also rises, and the progress of frost adhesion to the air heat exchanger 7 can be suppressed. Further, during the heat storage operation, the rotation speed of the circulation pump 20 is lowered to raise the temperature of the hot water supplied to the heat exchange terminal 13A, but the rotation speed of the circulation pump 20 is lowered to raise the temperature of the hot water. The circulation flow rate decreases, it becomes difficult for the heat exchange terminal 13A to dissipate heat, and the temperature of the hot water itself rises, but the room temperature of room A corresponding to the heat exchange terminal 13A does not rise too much, which causes discomfort to the user. Never.

More specifically, the rotation speed reduction control of the circulation pump 20 during the heat storage operation will be described more specifically. In the circulation pump control means 34, the hot water temperature detected by the return temperature sensor 22A during the heat storage operation becomes the heat storage target temperature. Until it reaches the limit, the rotation speed of the circulation pump 20 is controlled to be gradually reduced by a predetermined value at predetermined time intervals. The lower limit rotation speed of the circulation pump 20 that can be lowered during the heat storage operation is set in advance, the rotation speed of the circulation pump 20 is gradually lowered, and the hot water temperature detected by the return temperature sensor 22A is the heat storage target. If the rotation speed of the circulation pump 20 reaches a preset lower limit rotation speed before reaching the temperature, the circulation pump 20 is controlled by the lower limit rotation speed after reaching the temperature.

During the heating operation and the heat storage operation, when the outside air temperature is low, the air heat exchanger 7 gradually frosts. If a predetermined defrosting start condition is satisfied during the heat storage operation, the defrosting control means 38 starts executing the defrosting operation for melting the frost of the air heat exchanger 7 after the heat storage operation is completed. Is. The details of the defrosting operation will be described later.

The control procedure executed by the control unit 31 in order to realize the control during the heat storage operation will be described with reference to the flowchart of FIG. Here, a scene in which the heating operation is performed by the heat exchange terminal 13A will be described.

During the heating operation, when the heat storage control means 37 determines that the heat storage operation start condition is satisfied, the heat storage operation is started, and the counting means 39 starts counting the time of the heat storage operation (step S1).

After that, the target hot water temperature setting means 35 sets the heat storage target temperature as the target hot water temperature (target return temperature) (step S2), and proceeds to step S3. The method of setting the heat storage target temperature performed in step S2 will be described later.

In step S3, the target discharge temperature setting means 36 continuously sets the same temperature as the target discharge temperature set during the heating operation immediately before the start of the heat storage operation as the target discharge temperature, and in step S4, the circulation pump The control means 34 reduces the rotation speed of the circulation pump 20 by a predetermined value (for example, 100 rpm) from the rotation speed during the heating operation (for example, 3500 rpm).

After that, in step S5, the heat storage control means 37 determines whether or not a predetermined time (here, 1 minute) has elapsed. If 1 minute has not passed, the determination is not satisfied and the loop waits (step S5: NO), and after 1 minute has passed, the determination is satisfied (step S5: YES), and the process proceeds to step S6.

In step S6, the heat storage control means 37 determines whether or not the hot water temperature detected by the return temperature sensor 22A has reached the target hot water temperature (heat storage target temperature) set in step S2. If the hot water temperature detected by the return temperature sensor 22A does not reach the heat storage target temperature, the determination is not satisfied (step S6: NO), and the process proceeds to step S7. It is determined whether or not the defrosting start condition is satisfied. Here, the condition for starting the defrosting is satisfied by a condition set based on the outside air temperature and the refrigerant temperature on the outlet side of the air heat exchanger 7, for example, the outside air temperature is equal to or lower than a predetermined temperature (for example, 2 ° C.) and , Outside air temperature-Refrigerant temperature on the outlet side of the air heat exchanger 7> 8 ° C., or a certain time (for example, 40 minutes) has passed since the heat storage operation was started, that is, the counting means 39 counts. One of the conditions that the time exceeds a certain time is satisfied.

In step S7, if the predetermined defrosting start condition is not satisfied, the determination is not satisfied (step S7: NO), and the process proceeds to step S8. In step S8, the circulation pump control means 34 uses the current circulation pump 20. It is determined whether or not the rotation speed of is the lower limit rotation speed. If the current rotation speed of the circulation pump 20 is not the lower limit rotation speed, the determination is not satisfied (step S8: NO), the process proceeds to step S4, and the rotation speed of the circulation pump 20 is reduced by 100 rpm.

As described above, the hot water temperature detected by the return temperature sensor 22A has not reached the target hot water temperature (heat storage target temperature) (step S6: NO), and the defrosting start condition is not satisfied (step S7: NO). ), If the current rotation speed of the circulation pump 20 is not the lower limit rotation speed (step S8: NO), loop step S6: NO → step S7: NO → step S8: NO → step S4 → step S5 → step S6. However, the rotation speed of the circulation pump 20 decreases by 100 rpm every minute. Then, the hot water temperature detected by the return temperature sensor 22A has not reached the target hot water temperature (heat storage target temperature) (step S6: NO), and the defrosting start condition is not satisfied (step S7: NO). When the current rotation speed of the circulation pump 20 reaches the lower limit rotation speed (step S8: YES), the process proceeds to step S6, and thereafter, the rotation speed of the circulation pump 20 is the lower limit rotation speed until the heat storage operation is completed. Maintained in numbers.

In step S6, the hot water temperature detected by the return temperature sensor 22A did not reach the target hot water temperature (heat storage target temperature) (step S6: NO), but the defrosting start condition was satisfied (step S7: YES). In that case, the heat storage control means 37 ends the heat storage operation. Then, the defrost control means 38 starts the defrost operation.

Further, in step S6, when the hot water temperature detected by the return temperature sensor 22A reaches the target hot water temperature (heat storage target temperature), the determination is satisfied (step S6: YES), the process proceeds to step S9, and in step S9, The defrost control means 38 determines whether or not a predetermined defrost start condition is satisfied. Until the defrosting start condition is satisfied, the determination in step S9 is not satisfied (S9: NO), the loop waits, and when the defrosting start condition is satisfied, the determination is satisfied (step S9: YES), and the heat storage control means 37 stores heat. End the operation. Then, the defrost control means 38 starts the defrost operation.

As described above, in the heat pump type hot water heating system 1 of the present embodiment, during the heat storage operation, the target hot water temperature setting means 35 has a predetermined heat storage target higher than the target hot water temperature during the heating operation that has been set up to that point. The temperature is set as the target hot water temperature, the target discharge temperature setting means 36 maintains the target discharge temperature during the heating operation immediately before the heat storage operation, and the circulation pump control means 34 sets the rotation speed of the circulation pump 20 from that during the heating operation. I also try to reduce it.

Then, even if the target hot water temperature is set to a predetermined heat storage target temperature higher than before by the target hot water temperature setting means 35 during the heat storage operation, the target discharge temperature is set by the target discharge temperature setting means 36. , The one set at the time of the heating operation immediately before the start of the heat storage operation is maintained as it is, and the opening degree of the expansion valve 5 is not significantly changed by the expansion valve control means 33 and circulates to the air heat exchanger 7. Since the temperature of the refrigerant to be heated does not drop significantly, frost does not adhere to the air heat exchanger 7.

During the heat storage operation, the circulation pump control means 34 lowers the rotation speed of the circulation pump 20 as compared with the heating operation, so that the circulation flow rate of hot water per unit time is reduced and the temperature efficiency is increased. The temperature of the hot water flowing out of the exchanger 4 rises, the temperature of the hot water supplied to the heat exchange terminal 13A rises, and heat can be stored on the heat exchange terminal 13A side. Further, by lowering the rotation speed of the circulation pump 20 during the heat storage operation, the circulation flow rate of the hot water decreases, it becomes difficult for the heat exchange terminal 13A to dissipate heat, and the temperature of the hot water itself rises, but the heat exchange terminal 13A The room temperature of the corresponding space (room A) does not rise too much and does not cause discomfort to the user.

By doing the above, frost does not adhere to the air heat exchanger 7 and the defrosting time does not become long. Therefore, the amount of heat stored on the heat exchange terminal 13A is used to remove the heat. It is possible to cover the decrease in the temperature of the circulating fluid that decreases during the frost operation, and the comfort is not impaired during the defrost operation.

Further, during the heat storage operation, the circulation pump control means 34 gradually reduces the rotation speed of the circulation pump 20 until the temperature of the hot water reaches the heat storage target temperature.

This is because when the rotation speed of the circulation pump 20 is drastically reduced, the temperature of the hot water flowing out from the liquid refrigerant heat exchanger 4 rises at a stretch and becomes too high, and it is determined that the temperature is abnormal. Therefore, the heat exchange terminal 13A This is because the heat pump unit 2 may stop before the required amount of heat is stored on the side, and by gradually reducing the rotation speed of the circulation pump 20, the heat pump unit 2 is not stopped unnecessarily. The temperature of the hot water can be brought close to the heat storage target temperature, and the required amount of heat can be stored on the heat exchange terminal 13A side.

Further, during the heat storage operation, the circulation pump control means 34 reduces the rotation speed of the circulation pump 20, and when the rotation speed of the circulation pump 20 reaches a preset lower limit rotation speed, the circulation pump 20 is subsequently controlled by the lower limit rotation speed. ing.

This is because when the rotation speed of the circulation pump 20 is lowered endlessly, the circulation flow rate required to dissipate the heat of hot water at the heat exchange terminal 13A is not secured, and the space (room A) corresponding to the heat exchange terminal 13A cannot be secured. This is because there is a risk that heating will not be performed, and the lower limit rotation speed of the circulation pump 20 that can secure the circulation flow rate required to dissipate the heat of hot water at the heat exchange terminal 13A is set in advance, and the heat storage operation is performed. At that time, when the rotation speed of the circulation pump 20 reaches the lower limit rotation speed, the circulation pump 20 is controlled by the lower limit rotation speed thereafter so that the state in which heating is not performed during the heat storage operation does not occur. ..

Further, the compressor control means 32 controls the rotation speed of the compressor 3 so that the temperature of the hot water reaches the heat storage target temperature during the heat storage operation.

Since the target hot water temperature during the heat storage operation is set to a heat storage target temperature higher than the target hot water temperature during the heating operation, the heat storage operation is more than the temperature difference between the target hot water temperature and the hot water during the heating operation immediately before the heat storage operation. The temperature difference between the target hot water temperature (heat storage target temperature) and the hot water at the time becomes larger, and the rotation speed of the compressor 3 is controlled in an increasing direction. As a result, the circulating flow rate of the refrigerant passing through the liquid refrigerant heat exchanger 4 increases, and the amount of heat to be given from the refrigerant to the hot water in the liquid refrigerant heat exchanger 4 increases, so that the liquid refrigerant heat exchanger 4 flows out. The temperature of the hot water can be easily raised, and heat storage on the heat exchange terminal 13A side can be promoted. Further, since the rotation speed of the circulation pump 20 during the heat storage operation is lower than that during the heating operation, the amount of heat given to the hot water from the refrigerant in the liquid refrigerant heat exchanger 4 is reduced, and the refrigerant flowing out from the liquid refrigerant heat exchanger 4 is reduced. The temperature rises. Then, the temperature of the refrigerant circulated to the air heat exchanger 7 also rises, and the progress of frost adhesion to the air heat exchanger 7 can be suppressed.

Next, how to set the target hot water temperature (heat storage target temperature) in step S2 will be described. The heat storage target temperature is the temperature obtained by adding an additional value according to the amount of load factor that affects the magnitude of the heating load to the target hot water temperature during heating operation that has been set up to that point (heat storage target temperature = during heating operation). It is set to the target hot water temperature + additional value). The added value is determined according to the amount of the load factor, because the magnitude of the heating load is related as a factor for lowering the temperature of the hot water circulating in the circulation circuit 19. The size of the heating load varies from time to time, and in order to store the amount of heat stored in the heat storage operation on the heat exchange terminal 13 side, an additional value is determined according to the amount of load factor that affects the size of the heating load. There is a need.

The amount of load factor that affects the magnitude of the heating load includes the number of heat exchange terminals 13 performing the heating operation, and the heating load increases or decreases depending on the number of the heat exchange terminals 13 performing the heating operation. When the added value corresponding to the number of heat exchange terminals 13 performing the heating operation is set as the first added value, the first added value is that the smaller the number of the heat exchange terminals 13 performing the heating operation, the more the heat storage. A large value is set so that the target temperature is higher. The heating load itself is larger as the number of heat exchange terminals 13 performing the heating operation is larger, but when the number of heat exchange terminals 13 performing the heating operation is large, the amount of heat stored is large when the entire house is viewed, and hot water is used. In that case, the first addition value may be small. Therefore, as the first addition value, a large value is set so that the smaller the number of heat exchange terminals 13 performing the heating operation, the higher the heat storage target temperature, and conversely, the heating operation is performed. The larger the number of heat exchange terminals 13 is, the smaller the value is set.

The control procedure for realizing the target hot water temperature (heat storage target temperature) setting in step S2 according to the number of heat exchange terminals 13 performing the heating operation will be described by the flowchart of FIG. 7, first, heat storage. The control means 37 acquires the number of heat exchange terminals 13 during the heating operation (step S201A). The number of heat exchange terminals 13 during the heating operation is acquired by the number of operation ON signals of the heat exchange terminals 13 that are operating on the terminal setting screen 101 of the remote control 23 (in this embodiment, the heat during the heating operation). The exchange terminal 13 is only the heat exchange terminal 13A, and the number of heat exchange terminals 13 during the heating operation is 1.) It is sufficient to acquire the heat exchange terminal 13.

Subsequently, the heat storage control means 37 determines the first addition value X based on the acquired number of heat exchange terminals 13 during the heating operation (step S202A). As shown in step S202A, the heat storage control means 37 stores in advance table data indicating the correspondence between the number of heat exchange terminals 13 during the heating operation and the first addition value X. The first addition value X is determined based on the table data. Here, when the number of heat exchange terminals 13 during the heating operation is one, the first addition value X is determined to be 20 ° C., and when the number of heat exchange terminals 13 during the heating operation is two, the first addition is made. The value X is determined to be 20 ° C., and when the number of heat exchange terminals 13 during the heating operation is 3, the first addition value X is determined to be 15 ° C., and the number of heat exchange terminals 13 during the heating operation is 4. In the case of, the first additional value X is determined to be 15 ° C., and when the number of heat exchange terminals 13 during the heating operation is 5 or more, the first additional value X is determined to be 10 ° C.

Then, the heat storage control means 37 outputs the information of the first added value X determined in step S202A to the target hot water temperature setting means 35, and the target hot water temperature setting means 35 is during the heating operation that has been set up to that point. The heat storage target temperature is determined by adding the first addition value X to the target hot water temperature of (step S203), the heat storage target temperature is set as a new target hot water temperature (step S203), and the target hot water temperature (heat storage target temperature) in step S2. The setting is completed, and the process proceeds to the process of step S3 described above.

Further, as a load factor amount that affects the magnitude of the heating load, there is an outside air temperature in addition to the number of heat exchange terminals 13 performing the heating operation, and the heating load increases or decreases due to fluctuations in the outside air temperature. More specifically, the lower the outside air temperature, the larger the heating load. When the added value corresponding to the outside air temperature is set as the second added value, the second added value is set to a large value so that the lower the outside air temperature, the higher the heat storage target temperature.

Explaining the control procedure for realizing the target hot water temperature (heat storage target temperature) setting in step S2 by the flowchart of FIG. 8, first, the outside air temperature is detected by the outside air temperature sensor 11 (step S201B), and the heat storage control means. 37 determines the second addition value Y based on the outside air temperature detected by the outside air temperature sensor 11 (step S202B). As shown in step S202B, the heat storage control means 37 stores in advance table data indicating the correspondence between the outside air temperature T and the second addition value Y, and the second addition is based on this table data. The value Y is determined. Here, when the outside air temperature detected by the outside air temperature sensor 11 is less than -10 ° C, the second addition value Y is determined to be 10 ° C, and when the outside air temperature is -10 ° C or higher and lower than -5 ° C, the second addition value Y is determined to be 10 ° C. The added value Y is determined to be 7 ° C., and when the outside air temperature is −5 ° C. or higher and less than 2 ° C., the second added value Y is determined to be 5 ° C.

Then, the heat storage control means 37 outputs the information of the second added value Y determined in step S202B to the target hot water temperature setting means 35, and the target hot water temperature setting means 35 is during the heating operation that has been set up to that point. The heat storage target temperature is determined by adding the second addition value Y to the target hot water temperature of (step S203), the heat storage target temperature is set as a new target hot water temperature (step S203), and the target hot water temperature (heat storage target temperature) in step S2. The setting is completed, and the process proceeds to the process of step S3 described above.

Further, in order to set the target hot water temperature (heat storage target temperature) in step S2, the first addition value according to the number of heat exchange terminals 13 during the heating operation and the second according to the outside air temperature described above. Both of the added values may be used, and the control procedure for realizing the added value will be described by the flowchart of FIG. 9. First, the number of heat exchange terminals 13 during the heating operation is acquired ( Step S201A), the outside air temperature is detected by the outside air temperature sensor 11 (step S201B).

Subsequently, the heat storage control means 37 determines the first addition value X based on the acquired number of heat exchange terminals 13 during the heating operation, and the second addition value Y based on the outside air temperature detected by the outside air temperature sensor 11. Is determined (step S202C).

Then, the heat storage control means 37 outputs the information of the first addition value X and the second addition value Y determined in step S202C to the target hot water temperature setting means 35, and the target hot water temperature setting means 35 has been set up to that point. The heat storage target temperature is determined by adding the first addition value X and the second addition value Y to the target hot water temperature during the heating operation, and the heat storage target temperature is set as a new target hot water temperature (step S203). , The target hot water temperature (heat storage target temperature) setting in step S2 is completed, and the process proceeds to the process of step S3 described above.

As described above, in the heat pump type hot water heating system 1 of the present embodiment, during the heat storage operation, the target hot water temperature setting means 35 has a load that affects the target hot water temperature during the heating operation and the magnitude of the heating load. An additional value according to the factor amount is added to set the heat storage target temperature, and this heat storage target temperature is set as a new target hot water temperature.

This is because the size of the heating load is related as a factor for lowering the temperature of the hot water circulating in the circulation circuit 19, and if the size of the heating load is not taken into consideration, the amount of heat storage required for the heat storage operation is the heat exchange terminal 13. This is because heat cannot be stored on the side. If the size of the heating load is not taken into consideration, the amount of heat stored on the heat exchange terminal 13 side during the heat storage operation may be insufficient, and in that case, the amount of heat stored on the heat exchange terminal 13 side decreases during the defrosting operation. It is not possible to cover the temperature drop of the hot water, which may reduce the feeling of heating during defrosting operation and impair comfort, and if the size of the heating load is not taken into consideration, the heat exchange terminal during heat storage operation The amount of heat stored on the 13 side may become excessive, and in that case, the excess amount is merely dissipated on the heat exchange terminal 13 side, which may result in wasteful energy consumption.

Therefore, during the heat storage operation, the target hot water temperature setting means 35 sets the heat storage target temperature by adding an additional value according to the amount of the load factor that affects the magnitude of the heating load to the target hot water temperature during the heating operation. By setting the heat storage target temperature as a new target hot water temperature, the heat storage amount required for the heat storage operation can be stored on the heat exchange terminal 13 side without excess or deficiency.

Further, when setting the heat storage target temperature, the target hot water temperature setting means 35 uses the first addition value according to the number of heat exchange terminals 13 performing the heating operation as the load factor amount.

The amount of load factor that affects the magnitude of the heating load includes the number of heat exchange terminals 13 that are performing heating operation, and the first addition value according to the number of heat exchange terminals 13 that are performing heating operation. By using it, it is possible to set the heat storage target temperature corresponding to the size of the heating load.

Further, the value of the first addition value is set so that the smaller the number of heat exchange terminals 13 performing the heating operation, the higher the heat storage target temperature.

This is because the heating load itself increases as the number of heat exchange terminals 13 performing the heating operation increases, but when the number of heat exchange terminals 13 performing the heating operation increases, the amount of heat stored in the entire house is large. In this case, the first addition value may be small because the temperature of the hot water becomes large and the temperature of the hot water does not easily decrease. Therefore, the smaller the number of heat exchange terminals 13 performing the heating operation, the larger the value is set so that the heat storage target temperature becomes higher, and the larger the number of the heat exchange terminals 13 performing the heating operation, the smaller the value. By setting the value, it is possible to set an appropriate heat storage target temperature corresponding to the magnitude of the heating load.

Further, the target hot water temperature setting means 35 uses a second addition value according to the outside air temperature as a load factor amount when setting the heat storage target temperature.

As the amount of load factor that affects the magnitude of the heating load, the outside air temperature can be considered in addition to the number of heat exchange terminals 13 that are performing the heating operation, and by using the second addition value according to the outside air temperature, The heat storage target temperature can be set according to the size of the heating load.

The second added value is set so that the lower the outside air temperature, the higher the heat storage target temperature.

This is because the heating load increases as the outside air temperature decreases, and the second addition value is set to a larger value so that the lower the outside air temperature, the higher the heat storage target temperature. It is possible to set an appropriate heat storage target temperature corresponding to the magnitude of the load.

By using the added values of both the first added value and the second added value, it is possible to set the heat storage target temperature corresponding to the magnitude of the heating load. Therefore, when setting the heat storage target temperature, the target hot water temperature setting means 35 may use at least one of the first added value and the second added value.

Next, as a characteristic operation, a control for correcting the heat storage operation start condition will be described. As described above, the heat storage operation start condition is a condition that is satisfied before the defrosting start condition is satisfied, but the temperature of the hot water reaches the target hot water temperature (heat storage target temperature) during the heat storage operation. The time from the time until the defrosting start condition is satisfied varies greatly depending on the environmental conditions (temperature, humidity, etc.) of each region. Adjust the start timing of the heat storage operation so that the time from when the hot water temperature reaches the target hot water temperature (heat storage target temperature) until the defrosting start condition is satisfied is not too long or too short. That is, it is necessary to learn the environmental conditions of each region and correct the heat storage operation start conditions accordingly.

In the present embodiment, the heat storage control means 37 realizes the correction of the heat storage operation start condition, and the heat storage control means 37 has an outside air temperature of a predetermined temperature (for example, 2 ° C.) or less and an outside air temperature-air heat exchange. The heat storage operation start condition of the refrigerant temperature> 4 ° C. + α on the outlet side of the vessel 7 is stored in advance. Α in this equation is a correction value, and by changing this value, the heat storage operation start condition is corrected. In addition, zero is input as the initial value of α. Further, 6 ° C. (4 ° C. + α = 6 ° C.) is set as the upper limit of the temperature difference between the outside air temperature, which is the heat storage operation start condition, and the refrigerant temperature on the outlet side of the air heat exchanger 7, and the outside air temperature and the air heat are set. 2 ° C. (4 ° C. + α = 2 ° C.) is set as the lower limit of the temperature difference from the refrigerant temperature on the outlet side of the exchanger 7, and is stored in advance in the heat storage control means 37.

Here, in the heat storage control means 37, as shown in FIG. 10, the time t from when the temperature of the hot water reaches the heat storage target temperature to when the defrosting start condition is satisfied during the heat storage operation corresponds to the correction value α. Table data showing the relationship is stored in advance. The time from when the temperature of the hot water reaches the heat storage target temperature during the heat storage operation until the defrosting start condition is satisfied is measured by the measuring means 40, and the measurement time is a preset first time. If it is within the range (10 minutes or more and less than 20 minutes), the heat storage start condition correction means 41 selects α = 0 as the correction value so as not to correct the heat storage operation start condition at the next heat storage operation. To do.

When the measurement time is within the second time range (20 minutes or more and less than 30 minutes) longer than the first time range, the heat storage start condition correction means 41 selects α = 1 as the correction value. The condition for starting the heat storage operation at the next heat storage operation is corrected so as to delay the start of the heat storage operation. Here, selecting a positive value (here, 1) as the correction value α means that the outside air temperature and the outlet of the air heat exchanger 7 must be satisfied in order to satisfy the heat storage operation start condition at the next heat storage operation. The temperature difference from the refrigerant temperature on the side must be larger than this time, so the direction in which the heat storage operation start condition is difficult to be satisfied, that is, the direction closer to the defrosting start condition, is set to the heat exchange terminal 13 side. It means that the time for storing heat is reduced so that the wasted heat dissipation time is shortened.

Further, when the measurement time is within the third time range (30 minutes or more) longer than the second time range, the heat storage start condition correction means 41 selects α = 2 as the correction value and performs the next heat storage operation. The condition for starting the heat storage operation at the time is corrected so that the start of the heat storage operation is delayed more than when the measurement time is within the second time range.

When the measurement time is within the fourth time range (0 minutes or more and less than 10 minutes) shorter than the first time range, the heat storage start condition correction means 41 selects α = -1 as the correction value. , The condition for starting the heat storage operation at the next heat storage operation is corrected so that the start of the heat storage operation is accelerated. Here, selecting a negative value (here, -1) as the correction value α means that the outside air temperature and the air heat exchanger 7 are required to satisfy the heat storage operation start condition at the next heat storage operation. The temperature difference from the refrigerant temperature on the outlet side may be smaller than this time, and the heat storage operation start condition is likely to be satisfied, that is, the direction away from the defrost start condition is set to the start of the defrost operation. This means that the time for storing heat on the heat exchange terminal 13 side is increased.

If the defrosting start condition is satisfied before the temperature of the hot water reaches the heat storage target temperature during the heat storage operation, the heat storage start condition correction means 41 does not correspond to the measurement time of the measurement means 40 and is a correction value. Α = -1 is selected as, and the heat storage operation start condition at the next heat storage operation is corrected so that the start of the heat storage operation is accelerated. Here, it is necessary that the defrosting start condition is satisfied before the temperature of the hot water reaches the heat storage target temperature during the heat storage operation because the temperature of the hot water on the heat exchange terminal 13 side is lower than the heat storage target temperature. The defrosting operation will be started before the amount of heat storage is reached. Therefore, if the defrosting start condition is satisfied before the temperature of the hot water reaches the heat storage target temperature during the heat storage operation, a negative value (here, -1) is selected as the correction value α, and the next heat storage operation is performed. The heat storage operation start condition at that time is likely to be satisfied, that is, the direction away from the defrost start condition is set so that the time for storing heat on the heat exchange terminal 13 side is increased before the start of the defrost operation.

Next, the control procedure for realizing the correction of the heat storage operation start condition will be described with reference to the flowchart of FIG. Here, a scene in which the heating operation is performed by the heat exchange terminal 13A will be described.

When the heating operation is started, the heat storage start condition correction means 41 sets the heat storage operation start condition (step S11). In the case of the first heating operation after installation, zero is stored as the initial value in the correction value α, so the conditions for starting the heat storage operation are that the outside air temperature is below a predetermined temperature (for example, 2 ° C.) and the outside air temperature-air. The refrigerant temperature on the outlet side of the heat exchanger 7 is set to> 4 ° C.

Then, the heat storage control means 37 starts the heat storage operation set in step S11 based on the outside air temperature detected by the outside air temperature sensor 11 and the refrigerant temperature on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12. It is determined whether or not the condition is satisfied (step S12). If the heat storage operation start condition is not satisfied, the determination is not satisfied and the loop waits (step S12: NO). If the heat storage operation start condition is satisfied, the determination is satisfied (step S12: YES). (Step S13), the time counting of the heat storage operation by the counting means 39 is started (step S14), and the process proceeds to step S15.

In step S15, the heat storage control means 37 determines whether or not the hot water temperature detected by the return temperature sensor 22A has reached the target hot water temperature (heat storage target temperature) set by the target hot water temperature setting means 35. If the hot water temperature detected by the return temperature sensor 22A does not reach the target hot water temperature, the determination is not satisfied (step S15: NO), the process proceeds to step S16, and in step S16, the defrost control means 38 is set to a predetermined value. It is determined whether or not the defrosting start condition is satisfied. Here, the condition for starting the defrosting is satisfied by a condition set based on the outside air temperature and the refrigerant temperature on the outlet side of the air heat exchanger 7, for example, the outside air temperature is equal to or lower than a predetermined temperature (for example, 2 ° C.) and , Outside air temperature-Refrigerant temperature on the outlet side of the air heat exchanger 7> 8 ° C., or a certain time (for example, 40 minutes) has passed since the heat storage operation was started, that is, the counting means 39 counts. One of the conditions that the time exceeds a certain time is satisfied.

In step S16, if the predetermined defrosting start condition is not satisfied, the determination is not satisfied (step S16: NO), and the process proceeds to step S15. As described above, when the hot water temperature detected by the return temperature sensor 22A has not reached the target hot water temperature (heat storage target temperature) (step S15: NO) and the defrosting start condition is not satisfied (step S16: NO). , Step S15: NO → Step S16: NO → Step S15 will be looped. Then, if the hot water temperature detected by the return temperature sensor 22A reaches the target hot water temperature (heat storage target temperature) before the defrosting start condition is satisfied (step S15: YES), the process proceeds to step S17.

In step S17, the measuring means 40 starts measuring the time from when the temperature of the hot water reaches the heat storage target temperature until the defrosting start condition is satisfied, and proceeds to step S18.

In step S18, the defrost control means 38 determines whether or not the predetermined defrost start condition is satisfied. If the defrosting start condition is not satisfied, the determination is not satisfied and the loop waits (step S18: NO). If the defrosting start condition is satisfied, the determination is satisfied (step S18: YES), the heat storage operation is terminated, and step S19. Move to.

In step S19, the heat storage start condition correction means 41 determines the correction value α based on the measurement time measured by the measurement means 40. In step S19, the heat storage start condition correction means 41 determines the correction value α based on the measurement time of the measurement means 40 using the table data shown in FIG. 10, and a new correction value α is stored, and the step is described. Return to the process of S11. When the next heat storage operation is performed, the heat storage operation start condition to which the correction value α determined and stored in step S19 is applied is set in the heat storage operation start condition setting process in step S11.

In step S19, when the measurement time is within the first time range (10 minutes or more and less than 20 minutes), the heat storage start condition correction means 41 selects and determines the correction value α = 0, and during the next heat storage operation. The heat storage operation start condition of is not changed from the heat storage operation start condition at the time of the current heat storage operation, and is not substantially corrected.

In step S19, when the measurement time is within the second time range (20 minutes or more and less than 30 minutes), the heat storage start condition correction means 41 selects and determines α = 1 as the correction value, and performs the next heat storage operation. The condition for starting the heat storage operation at the time is corrected so as to delay the start of the heat storage operation as compared with the condition for starting the heat storage operation during the current heat storage operation.

In step S19, when the measurement time is within the third time range (30 minutes or more), the heat storage start condition correction means 41 selects and determines α = 2 as the correction value, and performs the heat storage operation at the next heat storage operation. The start condition is corrected in the direction of delaying the start of the heat storage operation as compared with the start condition of the heat storage operation at the time of the current heat storage operation, and the start of the heat storage operation is more than when the measurement time is within the second time range. Try to correct in the direction of delay.

In step S19, when the measurement time is within the fourth time range (0 minutes or more and less than 10 minutes), the heat storage start condition correction means 41 selects and determines α = -1 as the correction value in step S19. , The heat storage operation start condition at the next heat storage operation is corrected so as to start the heat storage operation earlier than the heat storage operation start condition at the current heat storage operation.

On the other hand, in step S15, the defrosting start condition is satisfied by the defrosting control means 38 before the hot water temperature detected by the return temperature sensor 22A reaches the target hot water temperature (heat storage target temperature) (step S15: NO). When it is determined that the heat storage has been performed (step S16: YES), in step S19, the heat storage start condition correction means 41 selects and determines α = -1 as the correction value, and sets the heat storage operation start condition at the next heat storage operation. Compared to the heat storage operation start condition during the heat storage operation this time, the correction is made so that the start of the heat storage operation is earlier.

As described above, in the heat pump type hot water heating system 1 of the present embodiment, the time from when the temperature of the hot water reaches the predetermined heat storage target temperature during the heat storage operation until the predetermined defrosting start condition is satisfied is measured. The measuring means 40 and the heat storage start condition correcting means 41 for correcting the heat storage operation start condition at the next heat storage operation according to the measurement time measured by the measuring means 40 are provided.

The heat storage operation start condition is a condition that is satisfied before the defrosting start condition is satisfied, but during the heat storage operation, from the time when the temperature of the hot water reaches the heat storage target temperature until the defrosting start condition is satisfied. Since the time varies greatly depending on the environmental conditions (temperature, humidity, etc.) of each region, if the time from when the temperature of the hot water reaches the heat storage target temperature until the defrosting start condition is satisfied becomes long, the heat exchange terminal The time for the heat storage to the 13A side to be wasted is lengthened, and the time from when the temperature of the hot water reaches the heat storage target temperature until the defrosting start condition is satisfied is short, or the temperature of the hot water. If the heat storage target temperature is not reached, the heat storage component on the heat exchange terminal 13A side may be insufficient.

Therefore, according to the measuring means 40 for measuring the time from when the temperature of the hot water reaches the predetermined heat storage target temperature during the heat storage operation until the predetermined defrosting start condition is satisfied, and the measurement time measured by the measuring means 40. By providing the heat storage start condition correction means 41 that corrects the heat storage operation start condition at the next heat storage operation, the start timing of the heat storage operation can be adjusted and the heat storage operation start condition that matches the environmental conditions of each region can be adjusted. It is possible to store heat on the heat exchange terminal 13A side in just proportion.

Further, when the measurement time measured by the measuring means 40 is in the second time range or the third time range longer than the preset first time range, the heat storage start condition correction means 41 sets the next heat storage operation start condition. The correction is made to delay the start of the heat storage operation.

The long time from when the temperature of the hot water reaches the heat storage target temperature during the heat storage operation until the defrosting start condition is satisfied means that it takes a long time to wastefully dissipate heat before the start of the defrosting operation. In that case, by correcting the direction to delay the start of the heat storage operation (the direction closer to the defrosting start condition) so that the next heat storage operation start condition is less likely to be satisfied, hot water will be used during the next heat storage operation. Heat storage to the heat exchange terminal 13A side by shortening the time from when the temperature reaches the heat storage target temperature until the defrosting start condition is satisfied and shortening the wasteful heat dissipation time until the defrosting operation starts. Can be prevented from becoming excessive.

Further, the heat storage start condition correction means 41 corrects the heat storage start condition correction means 41 in a direction in which the start of the heat storage operation is delayed as the measurement time measured by the measurement means 40 becomes longer.

This is because the longer the time from when the temperature of the hot water reaches the heat storage target temperature during the heat storage operation until the defrosting start condition is satisfied, the longer the wasteful heat dissipation time before the start of the defrosting operation. Therefore, the start of the heat storage operation is started so that the next heat storage operation start condition is less likely to be satisfied when the measurement time is within the third time range than when the measurement time is within the second time range. By compensating for a later direction (a direction closer to the defrosting start condition), the time from when the temperature of the hot water reaches the heat storage target temperature to when the defrosting start condition is satisfied during the next heat storage operation. It is possible to shorten the wasteful heat dissipation time until the start of the defrosting operation so that the heat storage on the heat exchange terminal 13A side does not become excessive.

Further, when the measurement time measured by the measuring means 40 is in the fourth time range shorter than the preset first time range, the heat storage start condition correction means 41 sets the next heat storage operation start condition to the start of the heat storage operation. I am trying to make corrections in the direction of acceleration.

The short time from when the temperature of the hot water reaches the heat storage target temperature during the heat storage operation until the defrosting start condition is satisfied means that the amount of heat storage may not be sufficient and may be insufficient. By correcting the direction in which the start of the heat storage operation is earlier (the direction away from the defrosting start condition) so that the next heat storage operation start condition is more likely to be satisfied, the temperature of the hot water will be adjusted in the next heat storage operation. The time from reaching the heat storage target temperature until the defrosting start condition is satisfied is lengthened so that the time for heat storage to the heat exchange terminal 13A side is increased before the defrosting operation is started, so that the heat exchange terminal 13A side is reached. It is possible to prevent the heat storage from becoming insufficient.

Further, when the measurement time measured by the measuring means 40 is within the preset first time range, the heat storage start condition correction means 41 does not correct the next heat storage operation start condition.

The optimum time is from when the temperature of the hot water reaches the heat storage target temperature during the heat storage operation until the defrosting start condition is satisfied, and the heat can be stored on the heat exchange terminal 13A side in just proportion. In that case, by not changing the next heat storage operation start condition from the current heat storage operation start condition, that is, by not correcting the next heat storage operation start condition, the temperature of the hot water will rise at the next heat storage operation. The time from when the heat storage target temperature is reached until the defrosting start condition is satisfied is also an optimum time, and heat can be stored in the heat exchange terminal 13A side in just proportion.

Further, in the heat storage operation, if the predetermined defrosting start condition is satisfied before the temperature of the hot water reaches the predetermined heat storage target temperature, the heat storage start condition correction means 41 sets the measurement time measured by the measuring means 40. Without responding (regardless of the measurement time measured by the measuring means 40), the next heat storage operation start condition is corrected so that the start of the heat storage operation is accelerated.

In the heat storage operation, the fact that the predetermined defrosting start condition is satisfied before the temperature of the hot water reaches the predetermined heat storage target temperature means that the amount of heat stored on the heat exchange terminal 13A side is insufficient. In that case, by correcting the direction in which the start of the heat storage operation is earlier (the direction away from the defrosting start condition) so that the next heat storage operation start condition is more likely to be satisfied, it will be removed in the next heat storage operation. By increasing the time for storing heat on the heat exchange terminal 13A side until the frost start condition is satisfied, it is possible to prevent the heat storage on the heat exchange terminal 13A side from becoming insufficient.

Next, the defrosting operation for melting the frost of the air heat exchanger 7 will be described. The defrosting operation of the present embodiment is a mode in which the refrigerant is circulated in the same direction as during the heating operation (so-called normal cycle defrosting), and the refrigerant discharged from the compressor 3 is passed through the liquid refrigerant heat exchanger 4. It passes through the expansion valve 5 and is supplied to the air heat exchanger 7 to melt the frost generated in the air heat exchanger 7.

In the defrosting operation, the defrosting control means 38 determines whether or not the defrosting start condition described above is satisfied, and if it is determined that the defrosting start condition is satisfied, the defrosting operation is started. The completion of the defrosting operation is determined by the defrosting control means 38 determining whether or not the predetermined defrosting end condition is satisfied, and if it is determined that the defrosting start condition is satisfied, the defrosting operation is completed. Become. The defrosting end condition is, for example, that the temperature of the refrigerant on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12 reaches a preset defrosting end temperature (for example, 5 ° C.). ..

When the defrosting operation is started, the defrosting control means 38 outputs a signal to the compressor control means 32 that the defrosting operation is in progress, and the compressor control means 32 receives the signal and the compressor 3 Is controlled by a preset defrosting rotation speed (constant rotation speed). Here, the compressor control means 32 controls the rotation speed of the compressor 3 based on the instruction from the defrost control means 38, but the defrost control means 38 directly controls the rotation speed of the compressor 3 during the defrost operation. , The same control can be performed even if the rotation speed of the compressor 3 is controlled.

Further, when the defrosting operation is started, a signal indicating that the defrosting operation is in progress is output from the defrosting control means 38 to the expansion valve control means 33, and the expansion valve control means 33 receives the signal and expands. The valve 5 is expanded to a predetermined opening degree (for example, fully open) that is larger than the opening degree during the heating operation so that the refrigerant passing through the expansion valve 5 is not depressurized by the expansion valve 5. Here, the expansion valve control means 33 controls the opening degree of the expansion valve 5 based on the instruction from the defrost control means 38, but the defrost control means 38 directly controls the opening degree of the expansion valve 5 during the defrost operation. Even if the opening degree of the expansion valve 5 is controlled, the same control can be performed.

Further, when the defrosting operation is started, a signal indicating that the defrosting operation is in progress is output from the defrosting control means 38 to the circulation pump control means 34, and the circulation pump control means 34 receives the signal and the refrigerant. The drive of the circulation pump 20 is controlled based on the refrigerant temperature detected by the temperature sensor 12. Here, the circulation pump control means 34 controls the drive of the circulation pump 20 based on the instruction from the defrost control means 38, but the defrost control means 38 directly controls the drive of the circulation pump 20 during the defrost operation. Similar control can be performed by controlling the drive of the circulation pump 20. In order to simplify the explanation, it is assumed that the defrost control means 38 directly controls the drive of the circulation pump 20 during the defrost operation.

Here, the drive control (rotational speed control) of the circulation pump 20 during the defrosting operation will be described. During the defrosting operation, the defrosting control means 38 continues to defrost the air heat exchanger 7 (in other words). Then, the expansion valve 5 is fully opened so that the high-temperature refrigerant flows through the air heat exchanger 7 to defrost the air heat exchanger 7), and the circulation pump 20 is based on the temperature detected by the refrigerant temperature sensor 12. Control the drive of. The details will be described below.

First, at the start of the defrosting operation, the defrosting control means 38 stops the driving of the circulation pump 20 which has been being driven until then, and stops the circulation of hot water. This is because when the circulation pump 20 is driven at the start of the defrosting operation, a part of the heat possessed by the refrigerant is absorbed by the hot water side by heat exchange between the refrigerant and the hot water in the liquid refrigerant heat exchanger 4. As a result, the amount of heat for defrosting the air heat exchanger 7 is deprived, and the defrosting of the air heat exchanger 7 does not proceed. Therefore, the drive of the circulation pump 20 is stopped at the start of the defrosting operation. In particular, since the amount of frost formed in the air heat exchanger 7 is large at the start of the defrosting operation, the circulation pump 20 is driven at the start of the defrosting operation so that the amount of heat retained by the refrigerant is used only for defrosting. It is better to stop it. The above-mentioned hot water circulation stop means that the flow of hot water is substantially stopped.

Then, during the defrosting operation, the defrosting control means 38 states that the temperature detected by the refrigerant temperature sensor 12 has reached a predetermined circulation pump drive start condition that is always satisfied before the defrosting end condition is satisfied. If it is determined, the rotation speed of the circulation pump 20 is driven at a rotation speed lower than that during the heating operation so that the hot water is circulated.

The circulation pump drive start condition is, for example, a circulation pump drive start temperature (higher than 0 ° C. and defrosting end temperature) in which the temperature of the refrigerant on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12 is preset. It is determined whether or not the temperature is lower than 5 ° C., for example, 1 ° C.) or higher, and when the defrosting control means 38 determines that the conditions for starting the drive of the circulation pump are satisfied, the circulation pump 20 is rotated at a predetermined speed lower than that during the heating operation. The drive is started at a number (for example, 1000 rpm), and as the temperature of the refrigerant on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12 approaches the direction in which the defrosting end condition is satisfied as it rises, it circulates. It is controlled so as to increase the rotation speed of the pump 20.

If the frost of the air heat exchanger 7 begins to melt during the defrosting operation, the amount of heat held by the refrigerant becomes excessive with respect to the amount of heat required for defrosting, and the refrigerant temperature detected by the refrigerant temperature sensor 12 rises. .. If nothing is done, excess heat other than the amount of heat required for defrosting is simply dissipated from the air heat exchanger 7, resulting in heat dissipation loss. When the temperature of the refrigerant on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12 rises to exceed a preset predetermined temperature in order to use the heat dissipation loss as the amount of heat for heating. , The circulation pump 20 is started to be driven at a lower rotation speed than during the heating operation, and a part of the heat possessed by the refrigerant is absorbed by the hot water side in the liquid refrigerant heat exchanger 4, and is used only for defrosting until then. A part of the heat generated is used for heating. Further, the fact that the temperature of the refrigerant on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12 rises and approaches the direction in which the defrosting end condition is satisfied is other than the amount of heat required for defrosting. This means that the amount of excess heat is increasing, and in such a case, it circulates as the temperature of the refrigerant on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12 approaches the direction in which the defrosting end condition is satisfied. The number of rotations of the pump 20 is increased, and the amount of heat used for heating is controlled to be increased.

At the start of the defrosting operation, since the amount of frost formed in the air heat exchanger 7 is large, the drive of the circulation pump 20 is stopped so that the amount of heat retained by the refrigerant is used only for defrosting. When the refrigerant temperature detected by the refrigerant temperature sensor 12 rises to a predetermined temperature during the frost operation, the circulation pump 20 is started to be driven to circulate hot water to the heat exchange terminal 13 for heating while continuing defrosting. Can also be done.

As shown in FIG. 12, the defrost control means 38 stores in advance table data showing the correspondence between the refrigerant temperature r on the outlet side of the air heat exchanger 7 and the drive rotation speed of the circulation pump 20. Therefore, the rotation speed of the circulation pump 20 is determined based on this table data. Here, when the refrigerant temperature detected by the refrigerant temperature sensor 12 is less than 1 ° C., the rotation speed of the circulation pump 20 is determined to be 0 rpm, that is, the state is stopped, and the refrigerant temperature detected by the refrigerant temperature sensor 12 is 1 ° C. If it is above and below 2 ° C, the rotation speed of the circulation pump 20 is determined to be 1000 rpm, and if the refrigerant temperature detected by the refrigerant temperature sensor 12 is 2 ° C or more and less than 3 ° C, the rotation speed of the circulation pump 20 is 1200 rpm. When the refrigerant temperature determined and detected by the refrigerant temperature sensor 12 is 3 ° C. or higher and lower than 5 ° C., the rotation speed of the circulation pump 20 is determined to be 1500 rpm.

Next, the control procedure for realizing the operation during the defrosting operation will be described with reference to the flowchart of FIG. Here, a scene in which the defrosting operation is performed while the heating operation (including the heat storage operation) by the heat exchange terminal 13A is performed will be described.

When the defrosting control means 38 determines that the defrosting start condition is satisfied during the heating operation, the defrosting operation for melting the frost of the air heat exchanger 7 is started, and first, the defrosting control means 38 , The circulation pump 20 is stopped to stop the circulation of hot water (step S21), the number of revolutions of the compressor 3 is driven by the number of revolutions at the time of defrosting, and the opening degree of the expansion valve 5 is fully opened. (Step S22), the process proceeds to step S23.

In step S23, the defrost control means 38 determines whether or not the circulation pump drive start condition is satisfied, that is, the refrigerant temperature detected by the refrigerant temperature sensor 12 is equal to or higher than the circulation pump drive start temperature (here, 1 ° C.). Determine if it is. If the refrigerant temperature detected by the refrigerant temperature sensor 12 does not reach 1 ° C., the determination is not satisfied (step S23: NO), the loop waits, and when the refrigerant temperature detected by the refrigerant temperature sensor 12 reaches 1 ° C. The determination is satisfied (step S23: YES), and the process proceeds to step S24.

In step S24, the defrost control means 38 determines the drive rotation speed of the circulation pump 20 according to the refrigerant temperature detected by the refrigerant temperature sensor 12, controls the drive of the circulation pump 20 at the determined rotation speed, and hot water. Let the circulation of. In step S24, the defrost control means 38 uses the table data shown in FIG. 12 to drive and rotate the circulation pump 20 based on the refrigerant temperature on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12. Determine the number.

In step S24, when the refrigerant temperature detected by the refrigerant temperature sensor 12 is 1 ° C. or higher and lower than 2 ° C., the rotation speed of the circulation pump 20 is determined to be 1000 rpm, and the refrigerant temperature detected by the refrigerant temperature sensor 12 is 2. When the temperature is equal to or higher than ° C and lower than 3 ° C, the rotation speed of the circulation pump 20 is determined to be 1200 rpm, and when the refrigerant temperature detected by the refrigerant temperature sensor 12 is 3 ° C or higher and lower than 5 ° C, the rotation speed of the circulation pump 20 is 1500 rpm. Is decided on. As an actual operation, when the circulation pump drive start condition is satisfied in step S23, first, in step S24, the circulation pump 20 is started to be driven at 1000 rpm from the stopped state, and the refrigerant temperature detected by the refrigerant temperature sensor 12 As the temperature rises, the rotation speed of the circulation pump 20 gradually increases to 1200 rpm and 1500 rpm.

Then, in step S25, the defrost control means 38 determines whether or not the predetermined defrost end condition is satisfied, that is, the refrigerant temperature detected by the refrigerant temperature sensor 12 is equal to or higher than the defrost end temperature (here, 5 ° C.). Judge whether or not it became. If the defrosting end condition is not satisfied, the determination is not satisfied (step S25: NO), the process returns to step S24, and if the defrosting end condition is satisfied, the determination is satisfied (step 25: YES), and the defrosting operation is performed. The process is completed, and the heating operation by the heat exchange terminal 13A is restarted.

As described above, in the heat pump type hot water heating system 1 of the present embodiment, the circulation of hot water is stopped at the start of the defrosting operation (normal cycle defrosting), and the air heat exchanger 7 is during the normal cycle defrosting. When it is determined that the predetermined conditions have been reached based on the refrigerant temperature detected by the refrigerant temperature sensor 12 while continuing the defrosting, the hot water is circulated to defrost during the defrosting operation. While performing the above, the circulation pump 20 can be appropriately driven to circulate hot water according to the temperature of the refrigerant on the outlet side of the air heat exchanger 7, and the heat exchange terminal 13A can also perform heating.

Further, the defrost control means 38 stops the circulation pump 20 at the start of defrosting, and drives the circulation pump in which the refrigerant temperature detected by the refrigerant temperature sensor 12 during the defrosting operation is established before the defrosting end condition is satisfied. When it is determined that the start condition has been reached, the rotation speed of the circulation pump 20 is driven at a lower speed than that during the heating operation, so that the amount of frost formed on the air heat exchanger 7 is reduced at the start of the defrosting operation. Due to the large amount, the circulation pump 20 is stopped to be defrosted intensively so that the amount of heat retained by the refrigerant is used only for defrosting, and the refrigerant temperature detected by the refrigerant temperature sensor 12 rises. Then, when the conditions for starting the operation of the circulation pump have risen, the circulation pump 20 is started to be driven at a lower rotation speed than during the heating operation so as not to take too much heat required for defrosting, and while continuing defrosting. In addition, hot water can be circulated to the heat exchange terminal 13A for heating, and the non-heating time during the defrosting operation can be shortened.

Further, after the defrost control means 38 determines that the circulation pump drive start condition has been reached, the refrigerant temperature detected by the refrigerant temperature sensor 12 is set in the direction in which the defrost end condition is satisfied (defrost end temperature). By increasing the rotation speed of the circulation pump 20 as it approaches, the refrigerant temperature detected by the refrigerant temperature sensor 12 reaches the circulation pump drive condition and then the defrosting end condition is satisfied. Approaching means that the temperature of the refrigerant on the outlet side of the air heat exchanger 7 is rising, and the excess heat amount other than the amount of heat required for defrosting the air heat exchanger 7 is increasing. In that case, the rotation speed of the circulation pump 20 is increased as the temperature of the refrigerant on the outlet side of the air heat exchanger 7 detected by the refrigerant temperature sensor 12 approaches the direction in which the defrosting end condition is satisfied. Therefore, the amount of heat used for heating can be increased, and the decrease in the feeling of heating during the defrosting operation can be suppressed.

The present invention is not limited to the one embodiment described above. In the present embodiment, the target hot water temperature setting and the target during the heat storage operation are performed in the case where the heating operation is performed only by the heat exchange terminal 13A. Although the discharge temperature setting, the rotation speed control of the compressor 3, and the rotation speed control of the circulation pump 20 are applied, if at least one of the plurality of heat exchange terminals 13 is in the heating operation, It is possible to apply the target hot water temperature setting, the target discharge temperature setting, the rotation speed control of the compressor 3, and the rotation speed control of the circulation pump 20 during the heat storage operation.

Further, in the present embodiment, the heat pump unit 2 is supposed to be capable of only heating operation, but may be a heat pump unit 2 capable of performing heating operation and cooling operation.

1 Heat pump type hot water heating system 2 Heat pump unit 3 Compressor 4 Liquid refrigerant heat exchanger 5 Expansion valve 7 Air heat exchanger 12 Refrigerant temperature sensor 13 Heat exchange terminal 19 Circulation circuit 20 Circulation pump 31 Control unit 38 Defrost control means

Claims (3)

A compressor for compressing the refrigerant, a liquid refrigerant heat exchanger for heat exchange between the circulating liquid and the refrigerant, a heat pump type heat source machine having an expansion valve and an air heat exchanger.
The liquid refrigerant heat exchanger of the heat pump type heat source machine, a heat exchange terminal that heats the air-conditioned space using the circulating liquid as a heat source, and a circulation pump that circulates the circulating liquid are connected by a pipe to form the above. A circulation circuit in which the circulating fluid circulates,
A control unit that controls the heat pump type heat source machine and the circulation pump to perform a heating operation so that the temperature of the circulating liquid supplied to the heat exchange terminal becomes the target hot water temperature.
In a heat pump type hot water heating system provided with a defrost control means for defrosting the air heat exchanger when a predetermined defrost start condition is satisfied during the heating operation.
A refrigerant temperature detecting means for detecting the refrigerant temperature on the outlet side of the air heat exchanger is provided.
The defrost control means circulates the refrigerant in the same direction as the flow direction of the refrigerant during the heating operation and expands the opening degree of the expansion valve as compared with the heating operation to defrost the air heat exchanger. The positive cycle defrosting is performed, the circulation of the circulating fluid is stopped at the start of the positive cycle defrosting, and the refrigerant is continued while the defrosting of the air heat exchanger is continued during the positive cycle defrosting. A heat pump type hot water heating system, characterized in that, when it is determined that a predetermined condition has been reached based on the refrigerant temperature detected by the temperature detecting means, the circulating liquid is circulated. The defrost control means stops the circulation pump at the start of the positive cycle defrosting, and the refrigerant temperature detected by the refrigerant temperature detecting means during the positive cycle defrosting has a predetermined defrosting end condition. Claim 1 is characterized in that, when it is determined that a predetermined circulation pump drive start condition that is satisfied before the establishment is reached, the rotation speed of the circulation pump is driven at a rotation speed lower than that during the heating operation. The heat pump type hot water heating system described. After determining that the refrigerant temperature detected by the refrigerant temperature detecting means has reached the predetermined circulation pump drive start condition during the positive cycle defrosting, the defrosting control means is used by the refrigerant temperature detecting means. The heat pump type hot water heating system according to claim 2, wherein the number of rotations of the circulation pump is increased as the detected refrigerant temperature approaches the direction in which the predetermined defrosting end condition is satisfied.

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