JP7295779B2 - Heat pump hot water heating system - Google Patents

Description

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

Conventionally, this type includes a heat pump type heat source device having a compressor, a liquid refrigerant heat exchanger, an expansion valve, and an air heat exchanger, and a circulation pump for circulating the circulating fluid. When performing defrosting, there is a so-called positive cycle defrosting method in which the refrigerant is circulated in the same direction as the refrigerant flow during operation. I had something to do. (For example, see Patent Document 1.)

JP 2012-26636 A

By the way, when it is assumed that this conventional system is applied to a hot water heating system, the circulation pump is kept stopped during normal cycle defrosting. If the circulation pump is stopped, the circulating fluid will not be supplied to the heat exchange terminal for heating the room during normal cycle defrosting. In addition, if the circulation pump continues to be driven so that the flow rate is very small during normal cycle defrosting, the heat exchange between the refrigerant and the circulating liquid in the liquid refrigerant heat exchanger reduces the amount of heat retained by the refrigerant. heat is absorbed by the circulating fluid side, the amount of heat for defrosting the air heat exchanger is taken, defrosting of the air heat exchanger does not progress, and defrosting may not be completed.

In order to solve the above problems, in claim 1, the present invention includes a compressor that compresses a refrigerant, a liquid refrigerant heat exchanger that exchanges heat between a circulating liquid and the refrigerant, an expansion valve, and an air heat exchanger. the liquid refrigerant heat exchanger of the heat pump heat source device; a heat exchange terminal that heats an 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 device and the circulation pump are controlled so that the temperature of the circulating fluid supplied to the heat exchange terminal and the circulating circuit formed by connecting the pipes to circulate the circulating fluid reaches the target hot water temperature. A heat pump hot water heating system comprising: a controller for performing a heating operation; and a defrosting control means for defrosting the air heat exchanger when a predetermined defrosting start condition is satisfied during the heating operation. wherein a refrigerant temperature detection means is provided for detecting the refrigerant temperature on the outlet side of the air heat exchanger, and the defrosting control means circulates the refrigerant in the same direction as the refrigerant flow direction during the heating operation and the expansion of the refrigerant. The opening of the valve is expanded more than during the heating operation to perform positive cycle defrosting for defrosting the air heat exchanger, and at the start of the positive cycle defrosting, the circulation of the circulating fluid is stopped, and the During normal cycle defrosting , if it is determined, based on the refrigerant temperature detected by the refrigerant temperature detecting means, that a predetermined circulating pump drive start condition, which is satisfied before a predetermined defrosting end condition is satisfied, is reached. , while continuing the defrosting of the air heat exchanger, the circulating fluid is circulated.

Further, in claim 2, the defrosting control means stops the circulation pump when the normal cycle defrosting is started, and during the normal cycle defrosting, the refrigerant temperature detected by the refrigerant temperature detecting means is When it is determined that a predetermined condition for starting driving the circulation pump, which is satisfied before the predetermined defrosting end condition is satisfied, the rotation speed of the circulation pump is driven at a lower rotation speed than 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 forward cycle defrosting. As the refrigerant temperature detected by the refrigerant temperature detection means approaches the direction in which the predetermined defrosting end condition is established, the rotation speed of the circulation pump is increased.

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

Further, according to claim 2, the defrosting control means stops the circulation pump when the normal cycle defrosting is started, and during the normal cycle defrosting, the refrigerant temperature detected by the refrigerant temperature detecting means reaches a predetermined defrosting temperature. If it is determined that the specified circulation pump drive start condition is satisfied before the end condition is satisfied, the rotation speed of the circulation pump is driven at a lower rotation speed than during heating operation. At the start, the amount of frost formed on the air heat exchanger is large, so that the circulation pump is stopped and defrosting is performed intensively so that the amount of heat stored in the refrigerant is used only for defrosting. When the refrigerant temperature detected by the refrigerant temperature detection means reaches the circulation pump drive start condition, the circulation pump is started at a lower rotational speed than during heating operation to prevent excessive heat loss required for defrosting. Therefore, while defrosting is continued, the circulating fluid can be circulated to the heat exchange terminal to perform heating, and the non-heating time during the defrosting operation can be shortened.

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

1 is a schematic configuration diagram of a heat pump hot water heating system according to an embodiment of the present invention; FIG. The figure showing the example of a screen display of a remote control. The figure showing the example of a screen display of the remote control at the time of heating operation. Main part block diagram. The figure explaining the operation|movement at the time of heating operation. 4 is a flowchart showing a control procedure during heat storage operation; 4 is a flowchart showing a control procedure for setting a heat storage target temperature; 4 is a flowchart showing another control procedure for setting the heat storage target temperature; 4 is a flowchart showing still another control procedure for setting the heat storage target temperature; Table data showing the correspondence relationship between the measurement time t and the correction value α used for correcting the heat storage operation start condition. 4 is a flowchart showing a control procedure for correcting a heat storage operation start condition; Table data showing the correspondence relationship between the refrigerant temperature r and the circulation pump rotation speed used for controlling the rotation speed of the circulation pump during defrosting operation. 4 is a flowchart showing a control procedure during defrosting operation;

Next, the configuration of the heat pump hot water heating system 1 according to one 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 that supplies heated circulating fluid. The heat pump unit 2 includes a variable speed compressor 3 for compressing the refrigerant and heat exchange between the refrigerant and the circulating fluid. A liquid refrigerant heat exchanger 4 that performs the above, an expansion valve 5 as a decompression means for decompressing the refrigerant, and an air heat exchanger 7 that exchanges heat with the air (outside air) sent by the operation of the blower fan 6, are annularly connected by a refrigerant pipe 8 to form a heat pump circuit 9 in which the refrigerant circulates. Any refrigerant such as HFC refrigerant or carbon dioxide refrigerant can be used as the refrigerant circulating in the heat pump circuit 9 . The liquid-refrigerant heat exchanger 4 is composed of, for example, a plate-type heat exchanger. The flow paths are formed alternately with each heat transfer plate as a boundary.

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

Reference numeral 13 is connected to the heat pump unit 2 via a forward pipe 14 and a return pipe 15 as piping, to which the circulating fluid heated by the heat pump unit 2 is supplied, and the space to be air-conditioned is heated using the supplied circulating fluid as a heat source. 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 three or more.

Here, one outgoing header 16 is provided in the middle of the outgoing pipe 14 extending from the liquid refrigerant heat exchanger 4 of the heat pump unit 2 toward the heat exchange terminal 13 . The upstream portion is configured as one common supply pipe 14a, and is a circulating fluid (for example, water, antifreeze, etc.) heated by the liquid-refrigerant heat exchanger 4 of the heat pump unit 2. Hereinafter, the heated circulating fluid is appropriately expressed as hot water) is supplied. Further, from the portion of the feed pipe 14 on the downstream side of the feed header 16, the number of individual feed pipes 14b corresponding to the number of heat exchange terminals 13 (three pipes in the illustrated example) are branched. A thermal valve 17 (17A, 17B, 17C) as a flow control valve is attached to each of the branched individual feed pipes 14b.

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 . Separate return pipes 15b for the number of heat exchange terminals 13 (three in the illustrated example) are branched from the upstream portion. A portion of the return pipe 15 on the downstream side of the return header 18 is configured as one common return pipe 15a. 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 housing of the heat pump unit 2 .

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 a forward pipe 14 and a return pipe 15, in which the circulating liquid circulates. A circulating pump 20 with a variable rotational speed that circulates the circulating fluid in the circulating circuit 19 and a cistern 21 that stores the circulating fluid and adjusts the pressure of the circulating circuit 19 are provided. Each of the individual return pipes 15b of the return pipe 15 is provided with a return temperature sensor 22 (22A, 22B) as temperature detection means for detecting the temperature of the circulating fluid flowing into the liquid flow path of the liquid-refrigerant heat exchanger 4. , 22C) are provided.

Reference numeral 23 denotes a remote controller installed on the wall surface of a room such as a living room. A timer switch 26 for instructing the terminal 13 to operate by a timer, an operation changeover switch 27 for instructing switching of the operation mode (normal mode, save mode, etc.) of the heat exchange terminal 13, and a screen display to the previous one. A return switch 28 for returning to the screen, a menu/decision switch 29, and cross keys 30 for up, down, left, and right directions are provided. Note that 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 two-way communication with a control section 31 to be 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 this embodiment, levels 1 to 9 can be set as the temperature level.

Here, the display of the remote controller 23 will be described with reference to FIG. 2. The display unit 24 can switchably display a plurality of setting screens (screens 100 to 101) under the control of the CPU. That is, in the example shown in FIG. 2( a ), the display unit 24 displays an overall setting screen 100 for performing 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 displayed in the main tab TM. (in this example, "OFF" indicating a stopped state is displayed).

On the other hand, in the example shown in FIG. 2B, the display unit 24 displays a terminal setting screen 101 for performing settings related to the heat exchange terminal 13, including operation start/stop settings of the heat exchange terminal 13. . The number of terminal setting screens 101 corresponding to the number of heat exchange terminals 13 to be connected (three in the present embodiment) can be provided. 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 power supply to the heat exchange terminal 13 is displayed on the right side of the screen. The temperature level of the hot water to be heated and an indicator representing the temperature level are displayed. In this example, the terminal setting screen 101 of the heat exchange terminal 13A corresponding to the room A as the space to be air-conditioned is displayed. It is displayed that it is set to 5. In addition, in the tab TA, a state display (“OFF” notation) representing the operating state of the heat exchange terminal 13A corresponding to the A chamber is provided. Although detailed explanation is omitted, the contents displayed on the terminal setting screen 101 of the heat exchange terminal 13B corresponding to the B room and the terminal setting screen 101 of the heat exchange terminal 13C corresponding to the C room 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 this embodiment, one remote controller 23 is used to set the operation of the three heat exchange terminals 13A, 13B, and 13C. It may be possible to set the operation of one heat exchange terminal 13 .

Reference numeral 31 denotes a control unit having storage means for storing various data and programs, and control means for performing arithmetic and control processing. In response, it controls the driving of the compressor 3, the expansion valve 5, the blower fan 6, the thermal valve 17, and the circulation pump 20 so that the temperature of the hot water supplied to the heat exchange terminal 13 reaches the target hot water temperature. Second, 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 for controlling the rotation speed of the compressor 3, an expansion valve control means 33 for controlling the opening degree of the expansion valve 5, and a rotation speed for the circulation pump 20. Circulation pump control means 34 for controlling , target hot water temperature setting means 35 for setting the target hot water temperature of the circulating fluid supplied to the heat exchange terminal 13, and setting the target discharge temperature of the refrigerant discharged from the compressor 3 and a target discharge temperature setting means 36 . The details of the control and processing contents of each means described above will be described later.

Further, the control unit 31 increases the temperature of the circulating fluid 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. and a defrosting control means 38 for performing a defrosting operation for melting the frost of the air heat exchanger 7. The heat storage control means 37 controls the time from the start of the heat storage operation. a measuring means 40 for measuring the time from when the temperature of the circulating fluid reaches the heat storage target temperature to when a predetermined defrosting start condition is satisfied during the heat storage operation, and the status of the current heat storage operation. and a heat storage start condition correction means 41 for correcting the next heat storage operation start condition based on. The details of the control and processing contents of each means described above will be described later.

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

First, with the terminal setting screen 101 displayed on the display unit 24 of the remote controller 23, when the user operates the operation/stop switch 25 of the remote controller 23 to issue an instruction to start the heating operation of the heat exchange terminal 13A, the control unit 31 receives the instruction signal. At this time, as shown in FIG. 3B, the display unit 24 of the remote controller 23 displays the operating state (A room temperature water heating operation) and temperature level (level 5), and the tab TA shows It becomes "ON" notation. On the general setting screen 100, as shown in FIG. 3A, the operating state (operating) of the heat pump unit 2 is displayed in the center of the screen, and "ON" is displayed in the tab TM.

When the instruction to start the heating operation is given, 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 degree of opening), and further, The controller 31 opens the thermal valve 17A corresponding to the heat exchange terminal 13A and starts driving the circulation pump 20, thereby starting the heating operation. During the heating operation, in the heat pump circuit 9, the 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 that functions as a condenser. It exchanges heat with the hot water flowing through the circuit 19, releases heat to the hot water, heats the hot water, and changes into a high-pressure refrigerant in a gas-liquid mixed state. Then, the refrigerant in this state is decompressed by the expansion valve 5 to become a low-pressure refrigerant and becomes a state of being easy to evaporate. 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 refrigerant flow indicated by the arrows in FIG. 5.)

On the other hand, in the circulation circuit 19, the hot water flowing into the liquid-refrigerant heat exchanger 4 by driving 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 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 the heat is radiated at the heat exchange terminal 13A to lower the temperature. The warm 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 thermal valve 17B corresponding to the heat exchange terminal 13B and the thermal 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. (Refer to the hot water flow 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 this 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 (for example, the hot water temperature associated with the temperature level - the predetermined temperature). is set. The compressor control means 32 controls the rotation speed of the compressor 3 so that the hot water temperature detected by the return temperature sensor 22A reaches the target return temperature set by the target hot water temperature setting means 35. , the temperature of the hot water supplied to the heat exchange terminal 13A is set to the temperature level set by the remote controller 23. FIG. 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. be.

To explain the rotation speed control of the compressor 3 in more detail, the compressor control means 32 controls the 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 rotation speed of the compressor 3 is increased or decreased according to the load, and the hot water temperature detected by the return temperature sensor 22A has not reached the target return temperature. If so, the rotation speed 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 rotation speed of the compressor 3 is decreased in order to maintain the hot water temperature detected by the return temperature sensor 22A at the target return temperature. It is.

In this 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 controller 23, and the inlet side of the liquid-refrigerant heat exchanger 4 The rotation speed of the compressor 3 is controlled so that the hot water temperature detected by the return temperature sensor 22 provided in the (inflow side) return pipe 15 reaches the target return temperature, that is, so-called return temperature control is performed. 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 it is as the target hot water temperature (target outgoing temperature), and the outlet side of the liquid refrigerant heat exchanger 4 A supply temperature sensor (not shown) is provided as temperature detection means in the supply pipe 14 (outflow side), and the rotation speed of the compressor 3 is adjusted so that the temperature of the hot water detected by the supply temperature sensor reaches the target supply temperature. It is also possible to perform so-called forward temperature control.

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 sets, in addition to the target hot water temperature set by the target hot water temperature setting means 35, a coefficient related to the rotation speed of the compressor 3 during heating operation and the outside air temperature sensor 11. A corresponding target discharge temperature (=target hot water temperature+coefficient related to the number of revolutions of the compressor 3+coefficient related to the outside air temperature) is set based on the coefficient related to the outside air temperature during heating operation. The expansion valve control means 33 controls the 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 . controls the opening of the

More specifically, the expansion valve control means 33 controls 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 degree of opening 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 direction of narrowing the degree of opening of the expansion valve 5 ( 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 degree of opening of the expansion valve 5 is adjusted to maintain the temperature of the refrigerant detected by the discharge temperature sensor 10 at the target discharge temperature. This is to control the opening direction.

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. Here, the description will be based on the scene where the heating operation is performed by the heat exchange terminal 13A. The heat storage operation raises the temperature of the circulating fluid 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 a condition 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 , are conditions under which the defrosting operation is assumed to start soon (conditions that are met before the defrosting start conditions are met).

During the heating operation, the heat storage control means 37 determines whether or not the conditions for starting the heat storage operation are satisfied, and starts the heat storage operation when determining that the conditions for starting the heat storage operation are satisfied. At the same time as the start of the heat storage operation, the counting means 39 also starts counting. When the heat storage operation is started, a signal indicating that the heat storage operation is being performed is output from the heat storage control means 37, and the target hot water temperature setting means 35 receives the signal, and the target return during the heating operation that has been set up until then is output. 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 reaches the heat storage target temperature set by the target hot water temperature setting means 35. As for the actual operation, immediately after the start of heat storage operation, the target return temperature (target hot water temperature) is changed to a heat storage target temperature that is higher than the target return temperature during heating operation that was set up until then. Therefore, the temperature difference between the hot water temperature detected by the return temperature sensor 22A and the target return temperature (target heat storage temperature) becomes larger than during the heating operation immediately before the heat storage operation. The rotation speed of the compressor 3 is increased. When the hot water temperature detected by the return temperature sensor 22A reaches the target return temperature (target heat storage temperature), the compressor 3 is operated to maintain the hot water temperature detected by the return temperature sensor 22A at the target return temperature. Decrease the rpm.

Further, when the heat storage operation is started, a signal indicating that the heat storage operation is being performed 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 is performed. Control is performed to maintain the target discharge temperature set during the heating operation immediately before starting the operation. That is, during the heat storage operation, unlike the heating operation, the setting method of changing the target discharge temperature according to the target return temperature (target hot water temperature) is not used. Even if the temperature is changed to the target temperature, the target discharge temperature set during the heating operation immediately before starting the heat storage operation is maintained as it is, and the target discharge temperature is maintained until the heat storage operation ends.

At this time, the target discharge temperature that was set during the heating operation immediately before starting the heat storage operation is maintained as it is, so the expansion valve control means 33 does not greatly change the opening of the expansion valve 5 , and 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 fluctuates to some extent, 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 greatly throttling (closing) does not occur, and the temperature of the refrigerant circulated in the air heat exchanger 7 does not decrease significantly.

Further, when the heat storage operation is started, a signal indicating that the heat storage operation is being performed is output from the heat storage control means 37 to the circulation pump control means 34. Upon receiving the signal, the circulation pump control means 34 controls the circulation pump. Means 34 controls the rotation speed of circulation pump 20 to be lower than during heating operation.

Here, assuming that the temperature of the hot water flowing into the liquid-refrigerant heat exchanger 4 is constant and the hot water is given a constant amount of heat from the refrigerant in the liquid-refrigerant heat exchanger 4, the rotation speed of the circulation pump 20 is reduced. Since the circulating flow rate of hot water per unit time is decreased and the temperature efficiency is increased when the temperature is increased, the temperature of the hot water flowing out from the liquid-refrigerant heat exchanger 4 is increased. Therefore, when the rotational speed of the circulation pump 20 is reduced during the heat storage operation, the temperature of the hot water supplied to the heat exchange terminal 13A can be increased. Furthermore, 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 rotational 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. It becomes easy to raise the temperature of hot water. In addition, since the rotation speed of the circulation pump 20 is lower than during the heating operation, the amount of heat given from the refrigerant to the hot water in the liquid-refrigerant heat exchanger 4 is reduced, and the temperature of the refrigerant flowing out of the liquid-refrigerant heat exchanger 4 is high. Become. As a result, the temperature of the refrigerant circulated to the air heat exchanger 7 also rises, and the progression of frost on the air heat exchanger 7 can be suppressed. In addition, the temperature of the hot water supplied to the heat exchange terminal 13A is increased by reducing the rotation speed of the circulation pump 20 during the heat storage operation. The circulating flow rate decreases, heat is less likely to be radiated at the heat exchange terminal 13A, and the temperature of the hot water itself rises, but the room temperature of the room A corresponding to the heat exchange terminal 13A does not rise excessively, which gives discomfort to the user. never

More specifically, the circulation pump control means 34 controls the hot water temperature detected by the return temperature sensor 22A to reach the target heat storage temperature during the heat storage operation. Control is performed so that the number of revolutions of the circulation pump 20 is gradually decreased by a predetermined value every predetermined period of time until the target value is reached. The lower limit of the rotation speed of the circulation pump 20 that can be lowered during the heat storage operation is set in advance. 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 at 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 is gradually frosted. When 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 on the air heat exchanger 7 after the heat storage operation is finished. is. Details of the defrosting operation will be described later.

A 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. 6 . Here, a scene in which the heat exchange terminal 13A performs the heating operation will be described.

During the heating operation, when the heat storage control means 37 determines that the conditions for starting the heat storage operation are satisfied, the heat storage control means 37 starts the heat storage operation, 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 the process 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 continues to set 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. The control means 34 reduces the rotation speed of the circulation pump 20 by a predetermined value (eg, 100 rpm) from the rotation speed during the heating operation (eg, 3500 rpm).

Thereafter, in step S5, the heat storage control means 37 determines whether or not a predetermined time (here, one minute) has elapsed. If one minute has not elapsed, the determination is not satisfied and the loop waits (step S5: NO), and if one minute has elapsed, 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 the hot water temperature detected by the return temperature sensor 22A has reached the target hot water temperature (target heat storage temperature) set in step S2. If the hot water temperature detected by the return temperature sensor 22A has not reached 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 met. Here, the defrosting start condition is established based on 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 a predetermined temperature (for example, 2 ° C.) or less, and , the condition that the outside air temperature-refrigerant temperature on the outlet side of the air heat exchanger 7 > 8 ° C., or that a certain time (for example, 40 minutes) has elapsed since the start of the heat storage operation, that is, the counting means 39 counts Either one of the conditions that the time exceeds a certain period of time must be 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. is the lower limit number of revolutions. 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), and the process proceeds to step S4 to reduce the rotation speed of the circulation pump 20 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 (target heat storage 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), step S6: NO → step S7: NO → step S8: NO → step S4 → step S5 → step S6 is looped. Then, the rotation speed of the circulation pump 20 decreases by 100 rpm every minute. The hot water temperature detected by the return temperature sensor 22A has not reached the target hot water temperature (target heat storage temperature) (step S6: NO), and the defrosting start condition has not been met (step S7: NO). If the current rotation speed of the circulation pump 20 reaches the lower limit rotation speed (step S8: YES), the process proceeds to step S6. maintained in numbers.

In step S6, the hot water temperature detected by the return temperature sensor 22A has not reached the target hot water temperature (target heat storage temperature) (step S6: NO), but the defrosting start condition is satisfied (step S7: YES). In this case, the heat storage control means 37 terminates the heat storage operation. Then, the defrosting control means 38 starts the defrosting operation.

Further, in step S6, when the hot water temperature detected by the return temperature sensor 22A reaches the target hot water temperature (target heat storage temperature), the determination is satisfied (step S6: YES), the process proceeds to step S9, and in step S9, Defrosting control means 38 determines whether or not a predetermined defrosting start condition is satisfied. Until the defrosting start condition is satisfied, the determination in step S9 is not satisfied (S9: NO) and the loop waits. finish driving. Then, the defrosting control means 38 starts the defrosting 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 sets a predetermined heat storage target higher than the target hot water temperature during the heating operation that has been set up until then. 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 increases the rotation speed of the circulation pump 20 from that during the heating operation. is also reduced.

Then, during the heat storage operation, even if the target hot water temperature setting means 35 sets the target hot water temperature to a predetermined heat storage target temperature higher than before, the target discharge temperature setting means 36 sets the target discharge temperature to , the value set during 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 greatly changed by the expansion valve control means 33, and the air is circulated to the air heat exchanger 7. Since the temperature of the refrigerant supplied to the air heat exchanger 7 does not drop significantly, the situation in which frost adheres to the air heat exchanger 7 does not occur.

During the heat storage operation, the rotation speed of the circulation pump 20 is reduced by the circulation pump control means 34 compared to that during the heating operation. 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. Furthermore, by reducing the number of revolutions of the circulation pump 20 during the heat storage operation, the circulation flow rate of the hot water is reduced, making it difficult for the heat to be dissipated at the heat exchange terminals 13A. The room temperature of the corresponding space (room A) does not rise excessively, and the user does not feel uncomfortable.

By doing so, the situation in which frost adheres to the air heat exchanger 7 does not progress, and the defrosting time does not become long. It is possible to make up for the decrease in the temperature of the circulating fluid during the frosting operation, and the comfort is not impaired during the defrosting operation.

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

This is because when the rotation speed of the circulation pump 20 is rapidly reduced, the temperature of the hot water flowing out of the liquid-refrigerant heat exchanger 4 rises at once and becomes too high, and it is judged as a high temperature abnormality, and the heat exchange terminal 13A. This is because the heat pump unit 2 may stop before the required amount of heat is stored in the side. It is possible to bring the temperature of the hot water close to the heat storage target temperature and store the required amount of heat 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 preset lower limit rotation speed is reached, thereafter controls the circulation pump 20 at the lower limit rotation speed. ing.

This is because if the rotation speed of the circulation pump 20 is infinitely lowered, the circulation flow rate necessary for radiating the heat of the hot water at the heat exchange terminal 13A cannot be ensured, and the space (chamber A) corresponding to the heat exchange terminal 13A is filled. 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 necessary for radiating the heat of the hot water at the heat exchange terminal 13A is set in advance, and the heat storage operation is performed. In this case, when the rotation speed of the circulation pump 20 reaches the lower limit rotation speed, the circulation pump 20 is controlled at the lower limit rotation speed after that, so that a state in which heating is not performed during the heat storage operation does not occur. .

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

The target hot water temperature during heat storage operation is set to a higher target hot water temperature than during heating operation. The temperature difference between the target hot water temperature (target heat storage temperature) and the hot water at this time becomes larger, and the rotational 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. It becomes easy to raise the temperature of hot water, and heat storage to the heat exchange terminal 13A side can be promoted. In addition, 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 from the refrigerant to the hot water in the liquid-refrigerant heat exchanger 4 decreases, and the refrigerant flowing out of the liquid-refrigerant heat exchanger 4 temperature rises. As a result, the temperature of the refrigerant circulated to the air heat exchanger 7 also rises, and the progression of frost on the air heat exchanger 7 can be suppressed.

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

A load factor that affects the magnitude of the heating load is the number of heat exchange terminals 13 performing heating operation, and the heating load increases or decreases depending on the number of heat exchange terminals 13 performing heating operation. When the addition value corresponding to the number of heat exchange terminals 13 performing heating operation is set as the first addition value, the first addition value increases as the number of heat exchange terminals 13 performing heating operation decreases. A large value is set so that the target temperature is higher. The heating load itself increases as the number of heat exchange terminals 13 performing heating operation increases. In this case, the first additional value may be small. Therefore, as the first addition value, a larger value is set so that the heat storage target temperature increases as the number of heat exchange terminals 13 performing heating operation decreases. A smaller value is set as the number of heat exchange terminals 13 that are connected is larger.

The control procedure for achieving the target hot water temperature (target heat storage temperature) setting in step S2 according to the number of heat exchange terminals 13 performing the heating operation will be described with reference to the flow chart of FIG. The control means 37 acquires the number of heat exchange terminals 13 in heating operation (step S201A). Acquisition of the number of heat exchange terminals 13 in the heating operation is performed by the number of operation ON signals of the heat exchange terminals 13 that are in operation on the terminal setting screen 101 of the remote controller 23 (in this embodiment, the number of heat exchange terminals 13 in the heating operation The heat exchange terminal 13 is only the heat exchange terminal 13A, and the number of the heat exchange terminals 13 in the heating operation is 1.) is sufficient.

Subsequently, the heat storage control means 37 determines the first addition value X based on the acquired number of heat exchange terminals 13 in 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 in the heating operation and the first addition value X. The first additional value X is determined based on the table data. Here, when the number of heat exchange terminals 13 in heating operation is one, the first addition value X is determined to be 20° C., and when the number of heat exchange terminals 13 in heating operation is two, the first addition When the value X is determined to be 20° C. and the number of heat exchange terminals 13 in heating operation is three, the first additional value X is determined to be 15° C. and the number of heat exchange terminals 13 in heating operation is four. , the first additional value X is determined to be 15.degree.

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

In addition to the number of heat exchange terminals 13 performing heating operation, the load factors that affect the magnitude of the heating load include the outside air temperature. More specifically, the lower the outside air temperature, the greater the heating load. When the addition value corresponding to the outside air temperature is set as the second addition value, the second addition value is set to a large value so that the heat storage target temperature becomes higher as the outside air temperature becomes lower.

The control procedure for setting the target hot water temperature (target heat storage temperature) in step S2 will be described with reference to the flowchart of FIG. 37 determines the second addition value Y based on the outside air temperature detected by the outside air temperature sensor 11 (step S202B). Note that the heat storage control means 37 stores in advance table data indicating the correspondence relationship between the outside air temperature T and the second addition value Y, as shown in step S202B. A 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 between -10°C and less than -5°C, the second addition value Y is determined to be 10°C. The additional value Y is determined to be 7.degree. C., and the second additional value Y is determined to be 5.degree.

Then, the heat storage control means 37 outputs the information of the second addition value Y determined in step S202B to the target hot water temperature setting means 35, and the target hot water temperature setting means 35 changes the value during the heating operation that has been set until then. The heat storage target temperature is determined by adding the second addition value Y to the target hot water temperature of , and 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 After the setting is completed, the process proceeds to step S3 described above.

Further, in order to set the target hot water temperature (target heat storage temperature) in step S2, the first addition value according to the number of heat exchange terminals 13 during heating operation and the second addition value according to the outside air temperature An added value of both added values may be used, and the control procedure for realizing it will be explained with reference to the flow chart of FIG. 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 in heating operation, and determines 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 sets 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 setting of the target hot water temperature (target heat storage temperature) in step S2 is completed, and the process proceeds to step S3 described above.

As described above, in the heat pump hot water heating system 1 of the present embodiment, during the heat storage operation, the target hot water temperature setting means 35 sets the target hot water temperature during the heating operation to the load that affects the magnitude of the heating load. The heat storage target temperature is set by adding an addition value corresponding to the factor amount, 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 to the factor that lowers the temperature of the hot water circulating in the circulation circuit 19. If the size of the heating load is not taken into account, the heat storage amount required for the heat storage operation is reduced to the heat exchange terminal 13 This is because heat cannot be stored on the side. If the magnitude 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. It is not possible to compensate for the temperature drop of the hot water, and the feeling of heating may decrease during defrosting operation, which may impair comfort. The amount of heat stored on the 13 side may become excessive, and in that case, the excess amount will simply be radiated on the heat exchange terminal 13 side, and there is a risk of wasting energy.

Therefore, during the heat storage operation, the target hot water temperature setting means 35 sets the heat storage target temperature by adding an addition value corresponding to the load factor amount 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 necessary for the heat storage operation can be stored in the heat exchange terminal 13 side just enough.

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

As a load factor amount that affects the magnitude of the heating load, there is the number of heat exchange terminals 13 that are performing heating operation, and the first addition value corresponding to the number of heat exchange terminals 13 that are performing heating operation is calculated. By using this, it is possible to set the heat storage target temperature corresponding to the magnitude of the heating load.

Also, the first addition value is set such that the smaller the number of heat exchange terminals 13 performing 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 heating operation increases. In this case, the first addition value may be small because the temperature of the hot water is difficult to drop. Therefore, the smaller the number of heat exchange terminals 13 performing heating operation, the higher the target heat storage temperature. By setting the value, an appropriate heat storage target temperature corresponding to the magnitude of the heating load can be set.

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

In addition to the number of heat exchange terminals 13 performing heating operation, the outside air temperature can be considered as a load factor amount that affects the magnitude of the heating load. It is possible to set the heat storage target temperature corresponding to the magnitude of the heating load.

Further, the second addition value is set such that the lower the outside air temperature, the higher the heat storage target temperature.

This is because the lower the outdoor temperature, the larger the heating load. The second additional value is set to a larger value so that the lower the outdoor 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 both the first addition value and the second addition value, it is possible to set the heat storage target temperature corresponding to the magnitude of the heating load. Therefore, the target hot water temperature setting means 35 may use at least one of the first addition value and the second addition value when setting the heat storage target temperature.

Next, as a characteristic operation, control for correcting the condition for starting the heat storage operation will be described. As described above, the heat storage operation start condition is a condition that is satisfied before the defrost start condition is satisfied. The time from when 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 temperature of the hot water reaches the target hot water temperature (target heat storage temperature) to when 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 this embodiment, the heat storage control means 37 corrects the conditions for starting the heat storage operation. A condition for starting the heat storage operation, that is, the refrigerant temperature on the outlet side of the device 7>4° C.+α, is stored in advance. α in this equation is a correction value, and by changing this value, the conditions for starting the heat storage operation are corrected. Note that zero is input as the initial value of α. In addition, the upper limit value of the temperature difference between the outside air temperature and the refrigerant temperature on the outlet side of the air heat exchanger 7, which is the condition for starting the heat storage operation, is set to 6°C (4°C + α = 6°C). 2° C. (4° C.+α=2° C.) is set as the lower limit value of the temperature difference from the refrigerant temperature on the outlet side of the exchanger 7 and stored in the heat storage control means 37 in advance.

As shown in FIG. 10, the heat storage control means 37 has a correspondence between the time t from when the hot water temperature reaches the heat storage target temperature to when the defrosting start condition is satisfied and the correction value α. Table data indicating the relationship is stored in advance. During the heat storage operation, the time from when the hot water temperature reaches the heat storage target temperature to when the defrosting start condition is satisfied is measured by the measuring means 40, and the measured 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 for the next heat storage operation. do.

Further, when the measured 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 heat storage operation start condition for 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 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 defrost start condition, and the heat exchange terminal 13 side This means reducing the heat storage time and shortening the wasted heat radiation time.

Furthermore, when the measured 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 the next heat storage operation is performed. The condition for starting the heat storage operation is corrected so that the start of the heat storage operation is delayed more than when the measured time is within the second time range.

Further, when the measured time is within a 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 heat storage operation start condition for the next heat storage operation is corrected so that the start of the heat storage operation is hastened. Here, selecting a negative value (here, −1) as the correction value α means that the outside air temperature and the air heat exchanger 7 must be The temperature difference from the refrigerant temperature on the outlet side can be smaller than this time, and the direction in which the heat storage operation start condition is easily satisfied, that is, the direction further away from the defrost start condition, until the defrost operation starts. This means that the time for storing heat on the heat exchange terminal 13 side is increased.

Note that when the defrosting start condition is established 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 sets the correction value α=−1 is selected as the value, and the heat storage operation start condition for the next heat storage operation is corrected so that the start of the heat storage operation is hastened. Here, the fact that the defrosting start condition is met before the temperature of the hot water reaches the target heat storage temperature during the heat storage operation means that the temperature of the hot water on the heat exchange terminal 13 side is lower than the target heat storage temperature. The defrosting operation will be started before the heat storage amount is reached. Therefore, when the defrosting start condition is satisfied before the temperature of the hot water reaches the target heat storage 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 direction in which the condition for starting the heat storage operation is likely to be established, that is, the direction away from the condition for starting the defrosting operation is set to increase the time for storing heat on the heat exchange terminal 13 side before the start of the defrosting operation.

Next, a control procedure for correcting the conditions for starting the heat storage operation will be described with reference to the flowchart of FIG. 11 . Here, a scene in which the heat exchange terminal 13A performs the heating operation will be described.

When the heating operation is started, the heat storage start condition correcting means 41 sets the heat storage operation start condition (step S11). When the heating operation is performed for the first time after the installation, zero is stored as the initial value for the correction value α. 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 conditions are met (step S12). If the conditions for starting the heat storage operation are not met, the determination is not satisfied and the loop waits (step S12: NO). is started (step S13), the counting of the heat storage operation time by the counting means 39 is started (step S14), and the process proceeds to step S15.

In step S<b>15 , the heat storage control means 37 determines whether or not the hot water temperature detected by the return temperature sensor 22</b>A 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 has not reached the target hot water temperature, the determination is not satisfied (step S15: NO), and the process proceeds to step S16. It is determined whether or not the defrosting start condition is satisfied. Here, the defrosting start condition is established based on 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 a predetermined temperature (for example, 2 ° C.) or less, and , the condition that the outside air temperature-refrigerant temperature on the outlet side of the air heat exchanger 7 > 8 ° C., or that a certain time (for example, 40 minutes) has elapsed since the start of the heat storage operation, that is, the counting means 39 counts Either one of the conditions that the time exceeds a certain period of time must be 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. Thus, when the hot water temperature detected by the return temperature sensor 22A has not reached the target hot water temperature (target heat storage temperature) (step S15: NO) and the defrosting start condition is not satisfied (step S16: NO). , step S15: NO→step S16: NO→step S15 is looped. If the hot water temperature detected by the return temperature sensor 22A reaches the target hot water temperature (target heat storage 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 to when the defrosting start condition is satisfied, and the process proceeds to step S18.

In step S18, the defrosting control means 38 determines whether or not a predetermined defrosting start condition is satisfied. If the defrosting start condition is not satisfied, the determination is not satisfied and the loop waits (step S18: NO). transition to

In step S<b>19 , 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 this step S19, the heat storage start condition correcting means 41 uses the table data shown in FIG. Return to the processing of S11. When the heat storage operation is performed next time, in the heat storage operation start condition setting process of step S11, the heat storage operation start condition is set to which the correction value α determined and stored in step S19 is applied.

In step S19, if the measured 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/determines the correction value α=0, The heat storage operation start condition of is not changed from the heat storage operation start condition of the current heat storage operation, and is not substantially corrected.

In step S19, if the measured 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/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 compared to the condition for starting the heat storage operation during the current heat storage operation.

In step S19, if the measured time is within the third time range (30 minutes or more), the heat storage start condition correction means 41 selects/determines α=2 as the correction value, and determines the heat storage operation for the next heat storage operation. The start condition is corrected so that the start of the heat storage operation is delayed compared to the heat storage operation start condition during the current heat storage operation, and the start of the heat storage operation is earlier than when the measured time is within the second time range. Correction is made in the direction of being more delayed.

In step S19, if the measured 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/determines α=−1 as the correction value in step S19. , the heat storage operation start condition for the next heat storage operation is corrected so that the start of the heat storage operation is earlier than the heat storage operation start condition for the current heat storage operation.

On the other hand, in step S15, before the hot water temperature detected by the return temperature sensor 22A reaches the target hot water temperature (target heat storage temperature) (step S15: NO), the defrosting start condition is established by the defrosting control means 38. If it is determined that it has been done (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 for the next heat storage operation to Compensation is made so that the start of the heat storage operation is earlier than the heat storage operation start condition of the current heat storage operation.

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

The heat storage operation start condition is a condition that is satisfied before the defrosting start condition is satisfied. The time varies greatly depending on the environmental conditions (temperature, humidity, etc.) of each region. The heat accumulated in the 13A side is wastefully dissipated for a long time, and the time from when the temperature of the hot water reaches the heat storage target temperature to when the defrosting start condition is satisfied is short, or the temperature of the hot water does not reach the heat storage target temperature, there is a possibility that the amount of heat stored in the heat exchange terminal 13A is insufficient.

Therefore, a measuring means 40 for measuring the time from when the temperature of the hot water reaches a predetermined heat storage target temperature during the heat storage operation until a predetermined defrosting start condition is satisfied, and the measured time measured by the measuring means 40 is In addition, by providing a heat storage start condition correction means 41 for correcting the heat storage operation start condition for the next heat storage operation, the start timing of the heat storage operation is adjusted, and the heat storage operation start condition suitable for the environmental conditions of each region is provided. , and the heat can be stored to the heat exchange terminal 13A side in just the right amount.

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 to Correction is made in the direction of delaying the start of the heat storage operation.

The fact that the time from when the temperature of the hot water reaches the target heat storage temperature to when the defrosting start condition is satisfied during the heat storage operation is long means that the heat is wasted for a long time before the defrosting operation starts. In that case, by correcting in the direction of delaying the start of the heat storage operation (in the direction closer to the defrosting start condition) so that the next heat storage operation start condition will be less likely to be satisfied than this time, hot water will be supplied during the next heat storage operation. After the temperature reaches the heat storage target temperature, the time until the defrosting start condition is satisfied is shortened, and the wasteful heat radiation time until the defrosting operation is started is shortened, so that heat is stored on the heat exchange terminal 13A side. can be prevented from becoming excessive.

In addition, the heat storage start condition correction means 41 corrects so that 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 hot water temperature reaches the heat storage target temperature during the heat storage operation to when the defrosting start condition is satisfied, the longer the time for which heat is wasted before the start of the defrosting operation. That is, when the measured time is within the third time range, the start of the heat storage operation is more difficult to satisfy than when the measurement time is within the second time range. By making corrections in the direction of delay (direction closer to the defrosting start conditions), the time from when the temperature of the hot water reaches the heat storage target temperature to when the defrosting start conditions are satisfied in the next heat storage operation. is shortened to shorten the wasteful heat radiation time until the start of the defrosting operation, thereby preventing excessive heat accumulation on the heat exchange terminal 13A side.

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 I'm trying to correct it in the direction of speeding it up.

The short time from when the hot water temperature reaches the heat storage target temperature to when the defrosting start condition is satisfied during the heat storage operation means that there is no margin in the heat storage amount and it may be insufficient. is corrected so that the next heat storage operation start condition will be more likely to be satisfied than this time, so that the heat storage operation start will be earlier (the direction away from the defrosting start condition), so that the hot water temperature will be higher during the next heat storage operation. The time from when the heat storage target temperature is reached to when the defrosting start condition is satisfied is increased, and the time for storing heat to the heat exchange terminal 13A side is increased before the defrosting operation is started, so that the heat exchange terminal 13A side is supplied with heat. It is possible to prevent the heat storage from becoming insufficient.

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

This is because the time from when the temperature of the hot water reaches the heat storage target temperature during the heat storage operation to when the defrosting start condition is satisfied is optimal, and the heat can be stored to the heat exchange terminal 13A side in just the right amount. In that case, the next heat storage operation start condition is not changed from the current heat storage operation start condition. The time from when the heat storage target temperature is reached to when the defrosting start condition is satisfied is also an optimum time, and heat can be stored to the heat exchange terminal 13A side in just the right amount.

Further, during the heat storage operation, if the predetermined defrosting start condition is met before the temperature of the hot water reaches the predetermined heat storage target temperature, the heat storage start condition correction means 41 corrects the heat storage start condition at 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 heat storage operation starts earlier.

During 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 in the heat exchange terminal 13A 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 than this time, the removal will be performed at the next heat storage operation. By increasing the time for heat storage to the heat exchange terminal 13A side until the frost start condition is established, the heat storage to the heat exchange terminal 13A side is less likely to run short.

Next, a defrosting operation for melting frost on 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 forward cycle defrosting), and the refrigerant discharged from the compressor 3 passes through the liquid refrigerant heat exchanger 4. It passes through the expansion valve 5, is supplied to the air heat exchanger 7, and melts frost generated in the air heat exchanger 7. - 特許庁

In the defrosting operation, the defrosting control means 38 determines whether or not the defrosting start condition described above is satisfied, and when 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 as to whether or not a predetermined defrosting end condition has been established. Become. The defrosting termination 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 termination temperature (eg, 5° C.). .

When the defrosting operation is started, a signal indicating that the defrosting operation is being performed is output from the defrosting control means 38 to the compressor control means 32, and the compressor control means 32 receives the signal, and the compressor 3 is controlled by a preset number of revolutions during defrosting (constant number of revolutions). Here, the compressor control means 32 controls the rotation speed of the compressor 3 based on the instruction from the defrosting control means 38, but during the defrosting operation, the defrosting control means 38 directly , the number of revolutions of the compressor 3 can be controlled.

Further, when the defrosting operation is started, the defrosting control means 38 outputs a signal to the effect that the defrosting operation is being performed 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 degree of opening (for example, fully opened) larger than the degree of opening during heating operation, so that the refrigerant passing through the expansion valve 5 is prevented from being decompressed by the expansion valve 5. - 特許庁Here, the expansion valve control means 33 controls the degree of opening of the expansion valve 5 based on instructions from the defrosting control means 38, but during the defrosting operation, the defrosting control means 38 directly , the opening degree of the expansion valve 5 can be controlled.

Further, when the defrosting operation is started, the defrosting control means 38 outputs a signal to the effect that the defrosting operation is being performed to the circulation pump control means 34, and the circulation pump control means 34 receives the signal, and the refrigerant is The driving of the circulation pump 20 is controlled based on the coolant temperature detected by the temperature sensor 12 . Here, the circulation pump control means 34 controls the driving of the circulation pump 20 based on the instruction from the defrosting control means 38, but during the defrosting operation, the defrosting control means 38 directly Similar control can also be performed by controlling the driving of the circulation pump 20 . To simplify the explanation, it is assumed that the defrosting control means 38 directly controls the driving of the circulation pump 20 during the defrosting operation.

Here, the drive control (rotational speed control) of the circulation pump 20 during the defrosting operation will be described. Then, while defrosting the air heat exchanger 7 by fully opening the expansion valve 5 to allow high-temperature refrigerant to flow through the air heat exchanger 7, the circulation pump 20 is operated based on the temperature detected by the refrigerant temperature sensor 12. control the drive of Details will be described below.

First, at the start of the defrosting operation, the defrosting control means 38 stops driving the circulation pump 20 which has been 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, part of the heat quantity retained by the refrigerant is absorbed by the hot water side due to heat exchange between the refrigerant and 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 progress. In particular, when the defrosting operation is started, the amount of frost formed on the air heat exchanger 7 is large. Therefore, the circulation pump 20 is driven when the defrosting operation is started so that the amount of heat stored in the refrigerant is used only for defrosting. Better to stop. It should be noted that the stoppage of hot water circulation means that the flow of hot water is substantially stopped.

During the defrosting operation, the defrosting control means 38 detects that the temperature detected by the refrigerant temperature sensor 12 has reached a predetermined circulation pump driving start condition that is always satisfied before the defrosting end condition is satisfied. When the determination is made, the circulation pump 20 is driven at a lower rotation speed than during the heating operation to circulate the hot water.

The circulation pump drive start condition is, for example, a circulation pump drive start temperature (higher than 0° C. and defrosting end temperature) at 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 When the defrost control means 38 determines that the circulation pump drive start condition is satisfied, the circulation pump 20 is rotated at a predetermined speed lower than during the heating operation. (for example, 1000 rpm), and 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. It controls to increase the rotation speed of the pump 20 .

When the frost on the air heat exchanger 7 begins to melt during the defrosting operation, the amount of heat stored in 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, the surplus heat amount other than the heat amount required for defrosting is simply radiated from the air heat exchanger 7, resulting in heat radiation 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 and reaches or exceeds a predetermined temperature in order to use the heat loss for heating as the amount of heat for heating. , the circulation pump 20 is started to be driven at a lower rotational speed than during the heating operation, and part of the heat quantity of the refrigerant in the liquid refrigerant heat exchanger 4 is absorbed by the hot water side, and is used only for defrosting until then. A part of the heat that was stored 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 means that the amount of heat other than the amount of heat required for defrosting This means that the amount of excess heat is increasing, and in such a case, 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, circulation It is controlled to increase the rotation speed of the pump 20 and increase the amount of heat used for heating.

At the start of the defrosting operation, the amount of frost formed on the air heat exchanger 7 is large. When the refrigerant temperature detected by the refrigerant temperature sensor 12 during the frost operation rises to a predetermined temperature, the circulation pump 20 is started to be driven, and the hot water is circulated to the heat exchange terminal 13 while defrosting is continued. can also be done.

As shown in FIG. 12, the defrosting control means 38 stores in advance table data indicating the correspondence relationship 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. 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, it is stopped, and the refrigerant temperature detected by the refrigerant temperature sensor 12 is 1°C. If the temperature is above 2°C and below 2°C, the rotation speed of the circulation pump 20 is determined to be 1000 rpm. When the determined refrigerant temperature detected by the refrigerant temperature sensor 12 is 3° C. or more and less 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 flow chart of FIG. Here, a scene in which the defrosting operation is performed while the heating operation (including the heat storage operation) is being performed by the heat exchange terminal 13A will be described.

During the heating operation, when the defrosting control means 38 determines that the defrosting start condition is satisfied, the defrosting operation for melting the frost of the air heat exchanger 7 is started. Then, the circulation pump 20 is stopped to stop the circulation of hot water (step S21), and furthermore, the rotation speed of the compressor 3 is driven at the defrosting rotation speed, and the opening degree of the expansion valve 5 is expanded to fully open. (Step S22), the process proceeds to step S23.

In step S23, the defrosting control means 38 determines whether or not the conditions for starting the driving of the circulation pump are satisfied, that is, the refrigerant temperature detected by the refrigerant temperature sensor 12 is equal to or higher than the temperature for starting driving the circulation pump (here, 1° C.). determine whether or not If the refrigerant temperature detected by the refrigerant temperature sensor 12 has not reached 1°C, the determination is not satisfied (step S23: NO), and the loop waits until 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 defrosting control means 38 determines the driving rotation speed of the circulation pump 20 according to the refrigerant temperature detected by the refrigerant temperature sensor 12, and controls the driving of the circulation pump 20 at the determined rotation speed. circulation. In this step S24, the defrosting control means 38 uses the table data shown in FIG. determine the number.

In step S24, when the refrigerant temperature detected by the refrigerant temperature sensor 12 is 1° C. or more and less 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. C. and less than 3.degree. 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.degree. is determined by As for the actual operation, when the condition for starting the circulation pump is satisfied in step S23, the circulation pump 20 is first started to be driven at 1000 rpm from the stopped state in step S24, and the refrigerant temperature detected by the refrigerant temperature sensor 12 is detected by the refrigerant temperature sensor 12. increases, the rotation speed of the circulation pump 20 is gradually increased to 1200 rpm and then to 1500 rpm.

Then, in step S25, the defrosting control means 38 determines whether or not a predetermined defrosting end condition is satisfied, that is, the refrigerant temperature detected by the refrigerant temperature sensor 12 is the defrosting end temperature (here, 5° C.) or higher. It is determined whether or not it has become 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 S25: YES), and the defrosting operation is started. It ends and the heating operation by the heat exchange terminal 13A is restarted.

As described above, in the heat pump hot water heating system 1 of the present embodiment, when the defrosting operation (positive cycle defrosting) is started, the hot water circulation is stopped, and during the positive cycle defrosting, the air heat exchanger 7 While continuing defrosting, when it is determined that a predetermined condition has been reached based on the refrigerant temperature detected by the refrigerant temperature sensor 12, hot water is circulated. , the circulation pump 20 is appropriately driven to circulate hot water according to the refrigerant temperature on the outlet side of the air heat exchanger 7, and heating can also be performed by the heat exchange terminal 13A.

Further, the defrosting control means 38 stops the circulation pump 20 at the start of defrosting, and during the defrosting operation, the circulation pump is driven such that the refrigerant temperature detected by the refrigerant temperature sensor 12 is established before the defrosting end condition is established. When it is determined that the starting condition has been reached, the rotation speed of the circulation pump 20 is driven at a lower rotation speed than during the heating operation, so that when the defrosting operation is started, the amount of frost formed on the air heat exchanger 7 is reduced. Therefore, the circulation pump 20 is stopped to defrost intensively so that the stored heat amount of the refrigerant is used only for defrosting, and the refrigerant temperature detected by the refrigerant temperature sensor 12 rises. When the temperature rises to the circulation pump drive start condition, the circulation pump 20 is started to be driven at a lower rotational speed than during the heating operation so as not to take too much heat necessary for defrosting, and defrosting is continued. Also, heating can be performed by circulating hot water to the heat exchange terminal 13A, and the non-heating time during the defrosting operation can be shortened.

Furthermore, 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 moves in the direction in which the defrost end condition is satisfied (defrost end temperature). By increasing the number of rotations of the circulation pump 20 as it approaches, the refrigerant temperature detected by the refrigerant temperature sensor 12 reaches the circulation pump driving 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 amount of excess heat other than the amount of heat required for defrosting the air heat exchanger 7 is increasing. In that case, 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 rotation speed of the circulation pump 20 is increased. Therefore, the amount of heat used for heating can be increased, and the reduction in the feeling of heating during the defrosting operation can be suppressed.

It should be noted that the present invention is not limited to the embodiment described above, and in this embodiment, when the heating operation is performed only by the heat exchange terminal 13A, the target hot water temperature setting during the heat storage operation, the target The discharge temperature setting, the rotation speed control of the compressor 3, and the rotation speed control of the circulation pump 20 are applied. Target hot water temperature setting, target discharge temperature setting, rotation speed control of the compressor 3, and rotation speed control of the circulation pump 20 during heat storage operation can be applied.

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

1 Heat Pump 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 Controller 38 Defrosting Control Means

Claims (3)

a heat pump heat source device having a compressor for compressing a refrigerant, a liquid-refrigerant heat exchanger for exchanging heat between the circulating liquid and the refrigerant, an expansion valve, and an air heat exchanger;
The liquid-refrigerant heat exchanger of the heat pump type heat source device, 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 piping. a circulation circuit in which the circulation fluid circulates;
a control unit for performing a heating operation by controlling the heat pump type heat source device and the circulation pump so that the temperature of the circulating fluid supplied to the heat exchange terminal reaches a target hot water temperature;
Defrosting control means for defrosting the air heat exchanger when a predetermined defrosting start condition is satisfied during the heating operation, in a heat pump hot water heating system comprising:
Refrigerant temperature detection means for detecting the refrigerant temperature on the outlet side of the air heat exchanger is provided,
The defrosting control means defrosts the air heat exchanger by circulating the refrigerant in the same direction as the refrigerant flow direction during the heating operation and expanding the opening degree of the expansion valve more than during the heating operation. When the normal cycle defrosting is started, the circulation of the circulating fluid is stopped, and during the normal cycle defrosting , based on the refrigerant temperature detected by the refrigerant temperature detection means If it is determined that a predetermined circulation pump drive start condition, which is satisfied before a predetermined defrosting end condition is satisfied, the circulating fluid is circulated while continuing the defrosting of the air heat exchanger. A heat pump hot water heating system characterized by: The defrosting control means stops the circulation pump when the normal cycle defrosting is started, and during the normal cycle defrosting, the refrigerant temperature detected by the refrigerant temperature detecting means is determined to cause the predetermined circulation pump to start driving. 2. The heat pump type hot water heating system according to claim 1, wherein, when it is determined that the condition is reached, the rotation speed of the circulation pump is driven at a rotation speed lower than that during the heating operation. After determining that the refrigerant temperature detected by the refrigerant temperature detection means reaches the predetermined circulation pump drive start condition during the normal cycle defrost, the defrost control means determines that the refrigerant temperature detection means 3. The heat pump type hot water heating system according to claim 2, wherein the rotation speed of said circulation pump is increased as the detected refrigerant temperature approaches the direction in which said predetermined defrosting end condition is satisfied.

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