Heat pump water heater

Abstract

To avoid instantaneous shutdown due to excess of power source capacity, etc. even when electric power consumption of a heat pump device is largely changed when finishing boiling.SOLUTION: An electric power control section 410G of a heating control device 50 includes: a zone setting section 410Gc that sets a zone A from an electric power consumption upper limit value X to electric power values B1, B2 and zones B, C on a low electric power side; and a boundary change section 410Gd that changes the electric power values B1, B2 on the basis of a target boiling-up temperature Tbo of hot water and an inflow water temperature T1 of a water-refrigerant heat exchanger 15. When a boiling finish state where the inflow water temperature T1 raises is reached, the electric power values B1, B2 are lowered to electric power values B1', B2' so that the zone A is expanded to the low electric power side, and HP electric power consumption is located within the zone A at a relatively early stage. As the result, forced lowering of a rotational frequency of a compressor 14 can be executed at an early stage.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a heat pump water heater that generates hot water by heat exchange with a refrigerant on a heat pump device side in a water-refrigerant heat exchanger. [Background technology]

[0002] Conventionally, in this type of heat pump water heater, as described in Patent Document 1, when an instruction to reduce power consumption in the heat pump device is input, the heat pump device is controlled so that the power consumption is kept below an upper limit value corresponding to the instruction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-96510 A Summary of the Invention [Problem to be solved by the invention]

[0004] A specific example of a case where power suppression control is performed to keep the power consumption of the heat pump device within the upper limit as in the above-mentioned conventional system is when the heat pump device operates by receiving power supply from an AC 100V household power source, etc. In such a case, in order to share the limited power supply capacity between the heat pump device and ordinary household electrical appliances, the rotation speed of the compressor is limited so that the power consumption of the heat pump device falls within the power consumption upper limit.

[0005] For example, when the generated hot water is stored in a small domestic hot water storage tank, the tank capacity is small, so the number of times boiling starts and stops during hot water generation operation (so-called boiling operation) increases. Just before boiling stops, the inlet temperature of the hot water flowing into the water-refrigerant heat exchanger rises, and the outlet temperature of the refrigerant from the water-refrigerant heat exchanger also rises, reaching a so-called end-of-boiling state. As a result, the temperature difference between the compressor discharge temperature and the above-mentioned refrigerant outlet temperature from the water-refrigerant heat exchanger becomes smaller, reducing the efficiency of the refrigeration cycle and causing a sudden increase in power consumption.

[0006] If there is a large change in the power consumption of the heat pump device when boiling ends, as described above, the compressor rotation speed cannot be suppressed in time using conventional current suppression control, and there is a risk that operation will be immediately stopped due to the power supply capacity being exceeded, etc. [Means for solving the problem]

[0007] In order to solve the above problem, claim 1 of the present invention provides a heat pump device having a compressor, an expansion valve, and an air heat exchanger connected by a refrigerant piping; a water-refrigerant heat exchanger that receives refrigerant from the heat pump device via the refrigerant piping and generates hot water for a hot water circulation circuit side by heat exchange with water; a circulation pump that circulates the hot water generated by the water-refrigerant heat exchanger; power reduction determination means that determines whether or not a power reduction signal that instructs reduction of power consumption in the heat pump device has been input; compressor control means that, when it is determined by the power reduction determination means that the power reduction signal has been input, controls the rotation speed of the compressor to increase or decrease so that the target compressor rotation speed corresponds to the power consumption upper limit value allowed by the power reduction signal; and a zone setting means for setting a first control zone which is a zone from the power consumption upper limit value to a first power reduction target value lower than the power consumption upper limit value, and a second control zone which is a zone on the lower power side than the first control zone, the first control zone being defined in order to control the rotation speed of the compressor in accordance with an actual power consumption value in the apparatus, and the compressor control means controls to forcibly reduce the rotation speed of the compressor when the actual power consumption value is within the first control zone.In a heat pump water heater, the heat pump water heater has a boundary changing means for changing the first power reduction target value which is the boundary between the first control zone and the second control zone, based on a target hot water temperature of hot water generated in the water-refrigerant heat exchanger and an inlet water temperature of hot water flowing into the water-refrigerant heat exchanger.

[0008] In addition, in claim 2, the second control zone includes a third control zone that is lower than the first power reduction target value and is an area up to a second power reduction target value that is lower than the first power reduction target value, and a fourth control zone that is an area on the lower power side of the second power reduction target value, and the compressor control means performs control to prohibit an increase in the compressor rotation speed when the actual power consumption value is within the third control zone, and the boundary change means changes the first power reduction target value, which is the boundary between the first control zone and the third control zone, and changes the second power reduction target value, which is the boundary between the third control zone and the fourth control zone, based on the target hot water temperature and the inlet water temperature.

[0009] In addition, in claim 3, the boundary change means changes the first power suppression target value to a lower value when the deviation between the target hot water temperature and the inlet water temperature becomes small, and changes the first power suppression target value to a higher value when the deviation between the target hot water temperature and the inlet water temperature becomes large.

[0010] In addition, in claim 4, the boundary change means changes the first power suppression target value to a lower value when the deviation between the target hot water temperature and the inlet water temperature becomes equal to or less than a first predetermined value, and changes the first power suppression target value to a higher value when the deviation between the target hot water temperature and the inlet water temperature becomes equal to or greater than a second predetermined value that is greater than the first predetermined value.

[0011] In addition, in claim 5, the zone setting means sets the first power reduction target value to be applied when the actual power consumption value increases and the first power reduction target value to be applied when the actual power consumption value decreases to be different values ​​from each other.

[0012] In addition, in claim 6, the hot water circulation circuit further includes an inlet water temperature detection means for detecting the inlet water temperature, a hot water temperature detection means for detecting the hot water temperature generated in the water-refrigerant heat exchanger in the hot water circulation circuit, and a pump control means for controlling the circulation pump, wherein the compressor control means and the pump control means perform hot water generation operation to generate the hot water in either of the following operating modes: a normal boiling operation mode in which the compressor is controlled to a predetermined first rotation speed and the flow rate of the circulation pump is controlled so that the hot water temperature detected by the hot water temperature detection means becomes the target hot water temperature, or a final boiling operation mode in which, in the normal boiling operation mode, when the inlet water temperature detected by the inlet water temperature detection means satisfies a predetermined temperature condition before the end of boiling, the compressor is controlled to a second rotation speed lower than the first rotation speed and the flow rate of the circulation pump is controlled to a flow rate higher than that in the normal boiling operation mode, and the boundary change means changes the first power suppression target value when the operation mode is the final boiling operation mode.

[0013] Furthermore, claim 7 relates to a zone setting means for setting the first power reduction target value based on the difference from the corresponding power consumption upper limit value, and the boundary change means for changing the first power reduction target value to a lower value by changing the difference to a larger value when the deviation between the target hot water temperature and the inlet water temperature becomes small, and for changing the first power reduction target value to a higher value by changing the difference to a smaller value when the deviation between the target hot water temperature and the inlet water temperature becomes large. Effect of the Invention

[0014] According to claim 1 of the present invention, in order to control the compressor rotation speed in accordance with the power consumption upper limit value when a power curtailment signal is input, a first control zone and a second control zone are set in advance by a zone setting means. The first control zone is set as a region from the power consumption upper limit value allowed by the power curtailment signal to a first power curtailment target value that is lower than the power consumption upper limit value. When the actual power consumption value in the heat pump device falls within this first control zone, the compressor rotation speed is forcibly reduced by the control of the compressor control means. At this time, in the present invention, the boundary changing means can change the first power suppression target value, which is the boundary between the first control zone and the second control zone, based on the target hot water temperature of the hot water generated in the water-refrigerant heat exchanger and the inlet water temperature of the hot water flowing into the water-refrigerant heat exchanger. As a result, when the inlet water temperature of the hot water rises and boiling is finished, the first power suppression target value can be lowered and the first control zone can be expanded to the low power side. When the first control zone is expanded to the low power side in this manner, the actual power consumption value of the heat pump device falls within the first control zone at a relatively early stage, and the compulsory reduction in the compressor speed is executed at an early stage. As a result, even if there is a large change in the power consumption of the heat pump device when boiling is finished, the compressor speed can be quickly suppressed, and an immediate operation stop due to exceeding the power supply capacity can be avoided.

[0015] According to claim 2, a first control zone, a third control zone, and a fourth control zone are set in advance by a zone setting means. The third control zone is set as a region from a first power suppression target value corresponding to the lower limit of the first control zone to a second power suppression target value lower than the first power suppression target value. When the actual power consumption value in the heat pump device falls within the second control zone, an increase in the compressor rotation speed is prohibited by control of the compressor control means. In the present invention, the boundary change means can change the first power suppression target value, which is the boundary between the first and third control zones, based on the target hot water temperature and the inlet water temperature. As a result, as in the above, when boiling is completed, the first power suppression target value can be lowered and the first control zone can be expanded toward the third control zone, which is on the low power side, so that the actual power consumption value in the heat pump device is located in the first control zone at a relatively early stage, and the compulsory reduction in the compressor speed is executed at an early stage. In particular, in the present invention, the power consumption upper limit value is located in the third control zone before it is in the first control zone, and the control to prohibit the increase in the speed is executed, so that the increase in the compressor speed can be more reliably avoided. As a result, the compressor speed can be reliably suppressed even if there is a large change in the power consumption of the heat pump device at the time of boiling completion.

[0016] According to claim 3, when the deviation between the target hot water temperature and the inlet water temperature becomes small, the first power suppression target value is changed to a lower value. This reliably expands the first control zone to the low power side in the end-of-boiling state where the inlet water temperature of the hot water rises, making it possible to avoid immediate operation shutdown due to exceeding the power supply capacity.

[0017] According to claim 4, when the boundary changing means changes (switches) the first power suppression target value in accordance with the deviation between the target hot water temperature and the inlet water temperature as described above, a threshold value (first predetermined value) when the deviation changes to a smaller value and a threshold value (second predetermined value) when the deviation changes to an larger value are set to different values. Specifically, the second predetermined value is set to a value larger than the first predetermined value. By providing such hysteresis, control instability such as the occurrence of hunting can be avoided, and smooth control can be performed.

[0018] According to claim 5, the first power suppression target value applied as the zone boundary between the first control zone and the second control zone (or the third control zone) as described above is set to a value (first power suppression target value) that is applied when the actual power consumption value in the heat pump device increases and a value (first power suppression target value) that is applied when the actual power consumption value decreases. By providing such hysteresis, it is possible to avoid control instability such as the occurrence of hunting and perform smooth control.

[0019] According to claim 6, the compressor control means and the pump control means, which respectively control the compressor and the circulating pump, have a normal boiling operation mode and a boiling end operation mode as operation modes. The boiling end operation mode is executed when the detected inlet water temperature satisfies a predetermined temperature condition before the end of boiling, and controls the compressor rotation speed to a second rotation speed lower than that in the normal boiling operation mode, and controls the flow rate of the circulating pump to a flow rate higher than that in the normal boiling operation mode. Then, when the boiling end operation mode is entered, the boundary change means controls to lower the first power suppression target value and expand the first control zone to the low power side. This makes it possible to suppress the compressor rotation speed more reliably when there is a large change in the power consumption at the end of boiling.

[0020] According to claim 7, when the boundary changing means expands the first control zone as described above, the expansion is performed by setting the first power suppression target value based on the difference from the corresponding power consumption upper limit value. This makes it possible to ensure that the difference between the first power suppression target value and the corresponding power consumption upper limit value is equal to or greater than a predetermined value, regardless of the value of the power consumption upper limit value, unlike when, for example, the first power suppression target value is defined as a ratio to the corresponding power consumption upper limit value. As a result, when boiling is complete, the actual power consumption value in the heat pump device can be reliably brought into the first control zone at an early stage, and the compressor rotation speed can be forcibly reduced at an early stage. [Brief description of the drawings]

[0021] [Figure 1] Schematic diagram of a hot water storage type hot water supply device according to one embodiment of the present invention. [Diagram 2] A functional block diagram showing the functional configuration of a heating control device [Diagram 3] An explanatory diagram illustrating the switching behavior between the normal boiling operation mode and the end-of-boiling operation mode. [Figure 4] FIG. 11 is an explanatory diagram showing an example of the behavior of the operation mode switching state, compressor rotation speed, boiling temperature, current consumption in the heat pump unit, discharge flow rate of the heating circulation pump, and inlet water temperature when switching from the normal boiling operation mode to the boiling end operation mode. [Diagram 5] An explanatory diagram explaining the three zone setting behaviors by the zone setting unit [Figure 6] A flowchart showing a control procedure executed by the heating control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Next, an embodiment of the present invention will be described with reference to the drawings.

[0023] <Schematic circuit configuration> As shown in FIG. 1, a storage type hot water supply device 100 according to this embodiment includes a tank unit 1 having a hot water storage tank 2 for storing hot water, and a heat pump unit 3 (corresponding to a heat pump hot water supply device).

[0024] The heat pump unit 3 includes a water-refrigerant heat exchanger 15 and a heating circulation pump 19 (corresponding to a circulation pump) for heating the hot water in the hot water storage tank 2. The water-refrigerant heat exchanger 15 has a refrigerant-side flow path 15b through which the refrigerant flows and a water-side flow path 15a, and exchanges heat between the high-temperature, high-pressure refrigerant and the hot water in the hot water storage tank 2. That is, the water-side flow path 15a of the water-refrigerant heat exchanger 15 and the hot water storage tank 2 are connected in a ring shape by a heating forward pipe 5 and a heating return pipe 6, and a heating circulation circuit 4 is formed as a hot water circulation circuit spanning the tank unit 1 and the heat pump unit 3.

[0025] The heating forward pipe 5 is connected to the lower part of the hot water storage tank 2, and the heating return pipe 6 is connected to the upper part of the hot water storage tank 2. The heating circulation pump 19 is provided in the middle of the heating forward pipe 5, and circulates the hot water in the hot water storage tank 2 while circulating the hot water from the heating forward pipe 5 to the heating return pipe 6 via the water side flow path 15a. The heating forward pipe 5 is provided with an inlet water temperature sensor 23 (corresponding to an inlet water temperature detection means) that detects the inlet water temperature T1 (hot water inlet temperature) sent from the hot water storage tank 2 to the water side flow path 15a of the water-refrigerant heat exchanger 15, and the heating return pipe 6 is provided with a boiling temperature sensor 24 (corresponding to a hot water temperature detection means) that detects the boiling temperature Tb of the water flowing out from the water side flow path 15a toward the hot water storage tank 2.

[0026] In the tank unit 1, a plurality of hot water temperature sensors 12 for detecting the temperature Tw of hot water in the hot water tank 2 are provided on the side surface of the hot water tank 2 from top to bottom. A water supply pipe 7 that supplies water to the hot water storage tank 2 is also connected to the lower part of the hot water storage tank 2, and a hot water outlet pipe 8 that discharges the stored high-temperature water is also connected to the upper part of the hot water storage tank 2. The hot water outlet pipe 8 is provided with a negative pressure intake valve 119 that opens to introduce air into the hot water storage tank 2 when negative pressure is created inside the hot water storage tank 2, and a water supply bypass pipe 9 branches off from the water supply pipe 7. In addition, there is provided a mixing valve 10 that mixes hot water from the hot water outlet pipe 8 with water from the water supply bypass pipe 9 to produce hot water at the hot water supply set temperature, a hot water supply pipe 108a for supplying the hot water mixed in the mixing valve 10 to the hot water supply terminal 125, and a hot water supply temperature sensor 11 that detects the hot water supply temperature in the hot water supply pipe 108a.

[0027] In addition, a hot water supply pipe 108b is provided on the hot water terminal 125 side of the hot water supply pipe 108a outside the tank unit 1, and a gas heat source unit 130 capable of heating the hot water mixed in the mixing valve 10 is provided between these hot water supply pipes 108a, 108b.

[0028] The heat pump unit 3 also includes a compressor 14 that compresses the refrigerant, an electronic expansion valve 16 as a pressure reducer that reduces the pressure of the refrigerant after passing through the water-refrigerant heat exchanger 15, an air heat exchanger 17 that exchanges heat between the refrigerant and air as a heat source, and an outdoor fan 67 that sends outside air to the air heat exchanger 17. The compressor 14, a flow path 15b on the refrigerant side of the water-refrigerant heat exchanger 15 through which the refrigerant discharged from the compressor 14 flows, the electronic expansion valve 16, and the air heat exchanger 17 are connected in a circular manner by refrigerant piping 18 to form a refrigerant circulation circuit 30.

[0029] The refrigerant circulation circuit 30 and the compressor 14, air heat exchanger 17, and electronic expansion valve 16 connected thereto correspond to a heat pump device. In this embodiment, the heat pump unit 3 including the compressor 14 and the tank unit 1 constituting the heat pump device are not provided with a dedicated power source, and both the heat pump unit 3 and the tank unit are configured to operate by receiving power supply from a household power source or a storage battery, which is an external power source that supplies, for example, AC 100V.

[0030] In the refrigerant circulation circuit 30, for example, an R32 refrigerant is used as a refrigerant, forming a heat pump cycle. A discharge temperature sensor 20 for detecting a refrigerant discharge temperature Tout of the refrigerant discharged from the compressor 14 is provided at a portion of the refrigerant piping 18 on the discharge side of the compressor 14, and an outside air temperature sensor 22 (corresponding to an outside air temperature detection means) for detecting an outside air temperature Tair is provided at an air inlet side of the air heat exchanger 17.

[0031] The tank unit 1 is provided with a hot water storage control device 40 to which the detection results of the sensors 12 and 11 are input. Similarly, the heat pump unit 3 is provided with a heating control device 50 to which the detection results of the sensors 20, 22, 23 and 24 are input. The heating control device 50 and the hot water storage control device 40 are connected to each other so as to be able to communicate with each other, and control the operation of each device in the tank unit 1 and the heat pump unit 3 while cooperating with each other based on the detection results of the sensors 24, 23, 12, 11, 20 and 22, etc.

[0032] Note that there may be a master-slave relationship in terms of control between the heating control device 50 and the hot water control device 40, and for example, the hot water control device 40 may output an operation command or a power suppression signal (described later) based on the detection results of the sensors 12, 11 to the heating control device 50, and the heating control device 50 may control the operation of each device in the heat pump unit 3 based on the operation command or power suppression signal and the detection results of each sensor 20, 22, 23, 24. In the following, this specification will be described taking such a case as an example.

[0033] <Heat pump input voltage / current detection device> The heat pump unit 3 is provided with a heat pump input voltage detection device 210 and a heat pump input current detection device 220 that detect the voltage value and current value input to the heat pump unit 3 from the external power supply using known sensors.

[0034] Furthermore, the heat pump unit 3 is provided with a heat pump power consumption detection device 200 that detects the power consumed within the heat pump unit 3 (hereinafter simply referred to as "HP power consumption" as appropriate, and the same applies to the drawings). The input voltage value detected by the heat pump input voltage detection device 210 and the input voltage value detected by the heat pump input current detection device 220 are each output to the heat pump power consumption detection device 200. The heat pump power consumption detection device 200 calculates the HP power consumption (corresponding to the actual power consumption value in the heat pump device) by integrating the voltage value detected by the heat pump input voltage detection device 210 and the current value detected by the heat pump input current detection device 220. The calculated HP power consumption is output to the heating control device 50.

[0035] <Heating control device> Next, a description will be given of the heating control device 50 provided in the heat pump unit 3. Although detailed illustration is omitted, the heating control device 50 includes a storage unit that stores various data and programs, and a control unit that performs calculation and control processing. The functional configuration of this heating control device 50 will be described with reference to FIG.

[0036] As shown in FIG. 2, the heating control device 50 functionally includes an operation switching unit 410A, a compressor control unit 410B (corresponding to a compressor control means), an expansion valve control unit 410C, an outdoor fan control unit 410D, a pump control unit 410F (corresponding to a pump control means), and a power control unit 410G.

[0037] The heat pump unit 3 of this embodiment performs various controls based on an operation command output from the hot water storage control device 40. That is, the operation command output from the hot water storage control device 40 is input to the operation switching unit 410A. The operation switching unit 410A determines whether or not to perform a boiling operation described below, which causes the air heat exchanger 17 to function as an evaporator, in response to the operation command. At this time, the operation switching unit 410A has an operation information output unit 410Aa. The operation information output unit 410Aa outputs operation information corresponding to the above-mentioned determination result (whether or not to perform the boiling operation) to the compressor control unit 410B, the expansion valve control unit 410C, the outdoor fan control unit 410D, the pump control unit 410F, and the power control unit 410G. The operation information includes the temperature Tw of the hot water in the hot water storage tank 2 detected by the hot water storage temperature sensor 12, and a target boiling temperature Tbo (corresponding to a target hot water temperature) determined appropriately.

[0038] In this example, the compressor control unit 410B receives the outdoor air temperature Tair detected by the outdoor air temperature sensor 22, the inlet water temperature T1 detected by the inlet water temperature sensor 23, and the operation information corresponding to the operation command of the hot water storage control device 40 (these may be input directly or indirectly, as below). The compressor control unit 410B also receives a determination result from a power suppression determination unit 410Ga described below, a current suppression value from a power suppression value acquisition unit 410Gb, the HP power consumption from the heat pump power consumption detection device 200, and a change result of the zone boundary by the boundary change unit 410Gd. The compressor control unit 410B has an operation mode determination unit 410Ba, a maximum rotation speed setting unit 410Bb, and a target rotation speed determination unit 410Bc.

[0039] The operation mode determination unit 410Ba determines, based on the inlet water temperature T1 from the inlet water temperature sensor 23, whether the heat pump unit 3 of this embodiment will operate in a normal boiling operation mode or a finish-boiling operation mode that are pre-prepared in advance.

[0040] That is, the normal boiling operation mode is a mode in which the rotation speed of the compressor 14 is controlled to a predetermined target rotation speed (corresponding to a first rotation speed) based on the outside air temperature Tair detected by the outside air temperature sensor 22 and the target boiling temperature Tbo, and the rotation speed of the heating circulation pump 19 is increased or decreased so that the boiling temperature Tb detected by the boiling temperature sensor 24 matches the target boiling temperature Tbo. The pump discharge flow rate of the heating circulation pump 19 at this time is hereinafter referred to as the "first flow rate" as appropriate.

[0041] The end-of-boiling operation mode is a mode in which, when the inlet water temperature T1 detected by the inlet water temperature sensor 23 during operation in the above-mentioned normal boiling operation mode satisfies the temperature conditions before the end of boiling (corresponding to the specified temperature conditions), the target rotation speed of the compressor 14 is controlled to be a rotation speed (second rotation speed) lower than the first rotation speed, and the discharge flow rate of the heating circulation pump 19 is controlled to be a flow rate (hereinafter referred to as the second flow rate) higher than the flow rate (first flow rate) in the normal boiling operation mode. The result of the operation mode determination by the operation mode determination unit 410Ba is input to the pump control unit 410F and the power control unit 410G.

[0042] The maximum rotation speed setting unit 410Bb determines the maximum value of the target rotation speed (maximum target rotation speed) of the corresponding compressor 14 based on the operation mode determination result by the operation mode determination unit 410Ba. The target rotation speed determination unit 410Bc sets a target rotation speed of the compressor 14 within the range of the maximum target rotation speed set by the maximum rotation speed setting unit 410Bb as described above, based on the input outside air temperature Tair and the target boiling temperature Tbo and the change result of the boundary change unit 410Gd, and controls the rotation speed of the compressor 14 to increase or decrease so as to achieve this target rotation speed (in detail, controls the motor that rotates the compressor 14).

[0043] Here, a specific switching method between the normal boiling operation mode and the boiling end operation mode is shown in FIG. 3. In FIG. 3, in this example, the predetermined temperature condition is defined by the difference between the target boiling temperature Tbo and the inlet water temperature T1. That is, when the difference between Tbo-T1 decreases and becomes Tbo-T1=15[°C] or less during operation in a state in which the operation mode is switched to the normal boiling operation mode by the operation mode decision unit 410Ba, the operation mode is switched from the normal boiling operation mode to the boiling end operation mode by the operation mode decision unit 410Ba. As a result, the target rotation speed of the compressor 14 is controlled from the first rotation speed to the second rotation speed, which is smaller than the first rotation speed, by the maximum rotation speed setting unit 410Bb and the target rotation speed decision unit 410Bc.

[0044] Conversely, when the difference between Tbo-T1 increases and Tbo-T1=17°C or more during operation in the end-of-boiling operation mode, the operation mode decision unit 410Ba switches from the end-of-boiling operation mode to the normal boiling operation mode. As a result, the target rotation speed of the compressor 14 is controlled by the maximum rotation speed setting unit 410Bb and the target rotation speed decision unit 410Bc from the second rotation speed to the first rotation speed, which is greater than the second rotation speed.

[0045] As described above, the value of Tbo-T1 (17°C) at which the operation mode is switched from the end-of-boiling operation mode to the normal boiling operation mode is different from the value of Tbo-T1 (15°C) at which the operation mode is switched from the normal boiling operation mode to the end-of-boiling operation mode. In other words, the former is larger, and a so-called control hysteresis is provided.

[0046] In this example, the expansion valve control unit 410C receives the refrigerant discharge temperature Tout detected by the discharge temperature sensor 20 and the operation information corresponding to the operation command of the hot water storage control device 40. In this example, the expansion valve control unit 410C controls the opening degree of the electronic expansion valve 16 to increase or decrease so that the refrigerant discharge temperature Tout becomes a desired target temperature for control.

[0047] The outdoor fan control unit 410D receives the outdoor air temperature Tair detected by the outdoor air temperature sensor 22 and the operation information corresponding to the operation command of the hot water storage control device 40. In this example, the outdoor fan control unit 410D sets a target rotation speed of the outdoor fan 67 based on the input operation information and the outdoor air temperature Tair, and controls the rotation speed of the outdoor fan 67 to increase or decrease to the target rotation speed.

[0048] The pump control unit 410F receives the boiling temperature Tb detected by the boiling temperature sensor 24 and the operation information (including the target boiling temperature Tbo) corresponding to the operation command of the hot water storage control device 40, and controls the rotation speed of the heating circulation pump 19 based on these so that the boiling temperature Tb coincides with the target boiling temperature Tbo. As already described, the operation mode determination result by the operation mode determination unit 410Ba of the compressor control unit 410B is also input to the pump control unit 410F. As a result, when the operation mode determination unit 410Ba switches from the normal boiling operation mode to the boiling end operation mode, the rotation speed is increased so that the discharge rate of the heating circulation pump 19 becomes a flow rate larger than the previous flow rate. Conversely, when the operation mode determination unit 410Ba switches from the boiling end operation mode to the normal boiling operation mode, the rotation speed is decreased so that the discharge rate of the heating circulation pump 19 becomes a flow rate smaller than the previous flow rate. The power control unit 410G will be described later.

[0049] <Power suppression control> On the other hand, when the compressor 14 of the heat pump unit 3 and the like operate by receiving power supply from a household power source or a storage battery as described above, the limited power supply capacity is shared with the tank unit 1 and each electrical appliance in the home. For this reason, in this embodiment, a power suppression signal instructing suppression of power consumption in the compressor 14 and the like is input from the hot water storage control device 40 to the power control unit 410G of the heating control device 50. The power suppression signal indicates an upper limit value of power consumption permitted to be consumed by the compressor 14 and the like.

[0050] In this example, the power control unit 410G receives a power restriction signal from the hot water storage control device 40 and the inlet water temperature T1 detected by the inlet water temperature sensor 23. The power control unit 410G also has a power restriction determination unit 410Ga (corresponding to a power restriction determination means) and a power restriction value acquisition unit 410Gb.

[0051] The power restriction determination unit 410Ga determines whether or not the power restriction signal has been input, and outputs the determination result to the target rotation speed determination unit 410Bc of the compressor control unit 410B. When it is determined that the power restriction signal has been input, the power restriction value acquisition unit 410Gb acquires the value of the power consumption upper limit specified by the power restriction signal, and outputs it to the target rotation speed determination unit 410Bc of the compressor control unit 410B and a zone setting unit 410Gc, which will be described later.

[0052] In response to the above, a target rotation speed determination unit 410Bc of the compressor control unit 410B sets a target rotation speed of the compressor 14 within the range of the maximum target rotation speed set by the maximum rotation speed setting unit 410Bb and within a range in which the HP power consumption input from the heat pump power consumption detection device 200 is equal to or less than the power consumption upper limit value from the power suppression determination unit 410Ga (=power suppression control). The target rotation speed determination unit 410Bc controls the rotation speed of the compressor 14 to increase or decrease so as to reach the target rotation speed set as described above.

[0053] <Concerns about switching to end-of-boil operation mode during power reduction control> As described above, in the heat pump unit 3 of this embodiment, the discharge side of the compressor 14 communicates with the inlet side of the water-refrigerant heat exchanger 15, and the suction side of the compressor 14 communicates with the outlet side of the air heat exchanger 17, thereby allowing the air heat exchanger 17 to function as an evaporator that evaporates the low-temperature, low-pressure refrigerant from the electronic expansion valve 16. That is, in the water-refrigerant heat exchanger 15, heat is released by the release of heat from the refrigerant in the refrigerant pipe 18, and hot water is generated in the heating circulation circuit 4. The generated hot water is supplied to the hot water storage tank 2 via the heating return pipe 6 by the flow of hot water in the heating circulation circuit 4 induced by the heating circulation pump 19, and the temperature of the hot water in the hot water storage tank 2 can be increased (= boiling operation as hot water generation operation).

[0054] Here, for example, as shown diagrammatically in FIG. 4, when the normal boiling operation mode is selected by the operation mode determination unit 410Ba during the boiling operation, the rotation speed N of the compressor 14 is controlled to be the first rotation speed N1 as described above, and the rotation speed of the heating circulation pump 19 is controlled so that the pump discharge flow rate V becomes the first flow rate V1. Then, when the operation in the normal boiling operation mode is performed for a certain period of time, the boiling of the hot water in the hot water storage tank 2 progresses, and the inlet water temperature T1 meets the predetermined temperature condition, the operation mode determination unit 410Ba switches to the boiling end operation mode at the timing of time to. As a result, the rotation speed N of the compressor 14 is controlled to the second rotation speed N2, which is smaller than before, and the pump discharge flow rate V of the heating circulation pump 19 is controlled to the second flow rate V2, which is larger than before, as a result of the control to make the boiling temperature Tb match the target boiling temperature Tbo. As a result, even if the temperature of the hot water circulating in the heating circulation circuit 4 becomes relatively high, the boiling can be continued by maintaining the boiling temperature Tb almost constant while suppressing the increase in the discharge pressure of the compressor 14.

[0055] However, in this boiling end operation mode, the inlet water temperature T1 of hot water flowing into the water side flow path 15a of the water-refrigerant heat exchanger 15 rises, and the outlet temperature of the refrigerant from the refrigerant side flow path 15b of the water-refrigerant heat exchanger 15 also rises. As a result, the temperature difference between the refrigerant discharge temperature Tout of the compressor 14 and the refrigerant outlet temperature from the water-refrigerant heat exchanger 15 decreases, reducing the efficiency of the refrigeration cycle and increasing the power consumption on the heat pump unit 3 side. Specifically, as shown in the figure, the pump discharge flow rate V (in other words, the pump rotation speed) of the heating circulation pump 19 increases rapidly, and as a result, the current consumption I (here, the current consumption is described as current consumption, but it may also be power consumption) in the heat pump unit 3 after switching to the boiling end operation mode increases rapidly compared to when operating in the normal boiling operation mode. When a large change in power consumption occurs in the heat pump unit 3 like this, the suppression of the rotation speed of the compressor 14 by the normal current suppression control as described above is not enough, and there is a risk of immediate operation stop due to exceeding the power supply capacity.

[0056] Therefore, in this embodiment, in addition to the power suppression determination unit 410Ga and the power suppression value acquisition unit 410Gb, the power control unit 410G is provided with a zone setting unit 410Gc (corresponding to a zone setting means) and a boundary change unit 410Gd (corresponding to a boundary change means).

[0057] <Setting the control zone using the zone setting section> The zone setting unit 410Gc sets a plurality of control zones for controlling the rotation speed of the compressor 14 in response to the HP power consumption from the heat pump power consumption detection device 200. The setting of these control zones will be explained with reference to Fig. 5(a). As shown in Fig. 5(a), in this example, three zones A, B, and C are set by the zone setting unit 410Gc.

[0058] Zone A is an area below the power consumption limit value X [VA], and is an area above B1 [VA] which is lower than the power consumption limit value X (in this example, by a difference of 30 [VA]), or above B2 [VA] which is lower than the power consumption limit value X (in this example, by a difference of 80 [VA]). That is, a so-called control hysteresis is provided by setting a zone boundary value B1 applied when the HP power consumption increases and moves into zone A, and a zone boundary value B2 applied when the HP power consumption decreases and moves out of zone A, to different values. Note that zone A corresponds to the first control zone, and B1 and B2 correspond to the first power suppression target value.

[0059] Zone B is a lower power region than Zone A, a region less than B1 and B2 [VA], and a region equal to or greater than B3 [VA], which is lower than the power consumption upper limit value X (in this example, by a difference of 150 [VA]). Specifically, in the direction in which the HP power consumption increases, it is a region equal to or greater than B3 [VA] and less than B1, and in the direction in which the HP power consumption decreases, it is a region equal to or greater than B3 [VA] and less than B2. Zone C is an area on the lower power side than zone B, and is an area below B3 [VA]. Zone B corresponds to the third control zone, zone C corresponds to the fourth control zone, and the entirety of zones B and C corresponds to the second control zone. Moreover, B3 corresponds to the second power suppression target value.

[0060] Furthermore, the control manner of the rotation speed of the compressor 14 by the target rotation speed determination unit 410Bc of the compressor control unit 410B differs depending on which of the zones A, B, and C the value of the HP power consumption corresponds to. That is, as shown in the table on the right side of FIG. 5(a), in the case of zone A, a target rotation speed that forcibly reduces the rotation speed of the compressor 14 from the current value is set regardless of the values ​​of the first rotation speed and the second rotation speed, and control based on the target rotation speed is performed. In the case of zone B, a target rotation speed that prohibits the rotation speed of the compressor 14 from increasing above the current value is set regardless of the values ​​of the first rotation speed and the second rotation speed, and control based on the target rotation speed is performed. Note that in the case of zone C, normal control is performed in which the target rotation speed is the first rotation speed or the second rotation speed as described above.

[0061] <Expansion of Zone A due to boundary changes> In this embodiment, in order to respond to the sudden fluctuation in HP power consumption during the end-of-boil operation, a process is performed to expand zone A to the low power side (in other words, a process to change the first power suppression target value, which is the boundary value between zones A and B) as shown in Figure 5(b) for zones A, B, and C set by the zone setting unit 410Gc as described above.

[0062] In this example, shown in Fig. 5(b) which has been changed from Fig. 5(a), zone A is an area below the power consumption upper limit value X [VA], and is an area above B1' [VA] which is lower than the power consumption upper limit value X (in this example, by a difference of 50 [VA]), or above B2' [VA] which is lower than the power consumption upper limit value X (in this example, by a difference of 100 [VA]). As in the above, a control hysteresis is provided, and B1' and B2' correspond to the first power suppression target value.

[0063] Zone B is an area less than B1' and B2' [VA] and is equal to or greater than B3' [VA], which is lower than the power consumption upper limit value X (in this example, by a difference of 170 [VA]). Zone C is an area less than B3' [VA], on the lower power side than Zone B. B3' corresponds to the second power suppression target value.

[0064] In the case of zones A, B, and C shown in FIG. 5(b), the control manner by the target rotation speed determination unit 410Bc of the compressor control unit 410B is the same as that shown on the right side of FIG. 5(b), where in zone A, control is performed to forcibly reduce the rotation speed, in zone B, control is performed to prohibit an increase in the rotation speed, and in zone C, normal control is performed.

[0065] The change between zones A, B, and C shown in Fig. 5(a) and zones A, B, and C shown in Fig. 5(b) is made based on the target boiling temperature Tbo and the inlet water temperature T1, similar to the change between the normal boiling operation mode and the end-of-boiling operation mode. In particular, in this example, similar to the change between the two operation modes, when the difference between Tbo-T1 decreases and becomes Tbo-T1=15[°C] (corresponding to the first predetermined value) or less, the change is made from Fig. 5(a) to Fig. 5(b), and when the difference between Tbo-T1 increases and becomes Tbo-T1=17[°C] (corresponding to the second predetermined value) or more, the change is made from Fig. 5(b) to Fig. 5(a).

[0066] <Control procedure> The control procedure executed by the heating control device 50 of this embodiment to realize the above method will be described with reference to the flowchart of FIG.

[0067] In Fig. 6, this flow starts in the operating state in the normal boiling operation mode. That is, the operation mode determination unit 410Ba determines the operation in the normal boiling operation mode, and based on the determination result, the compressor 14 is controlled to the first rotation speed via the maximum rotation speed setting unit 410Bb and the target rotation speed determination unit 410Bc. Also, the rotation speed is controlled by the pump control unit 410F so that the discharge amount of the heating circulation pump 19 becomes the first flow rate. Then, first, in S2, a flag F indicating the presence or absence of an input of a power suppression command is initialized to 0.

[0068] Thereafter, in S5, the operation mode determination unit 410Ba determines whether the condition for switching to the end-of-boiling operation mode (end-of-boiling condition) is satisfied based on the inlet water temperature T1 from the inlet water temperature sensor 23. In the example shown in FIG. 3, it determines whether the difference between Tbo and T1 has decreased to Tbo-T1=15°C. If the end-of-boiling condition is not satisfied, the determination is No, and the process proceeds to S10.

[0069] In S10, the operation in the normal boiling operation mode that has been started as described above is continued. That is, as described above, the compressor 14 is controlled to have the first rotation speed, and the rotation speed is controlled so that the discharge amount of the heating circulation pump 19 becomes the first flow rate.

[0070] Then, in S12, it is determined whether F = 1. For example, if F = 1 at this point due to processing in S20 or S55 described later, the determination is Yes, and the process moves to S30 described later. If F remains 0, the determination is No, and the process moves to S15.

[0071] In S15, the power restriction determination unit 410Ga of the power control unit 410G determines whether or not the power restriction signal is input from the hot water storage control device 40. If the power restriction signal is not input, the result is No and the process proceeds to S42 described below, and if the power restriction signal is input, the result is Yes and the process proceeds to S20. In S20, the flag F is set to 1.

[0072] After S20, in S30, the zone setting unit 410Gc and the boundary changing unit 410Gd of the power control unit 410G perform the zone division setting shown in Fig. 5(a). That is, in the above-mentioned example, the values ​​of B1, B2, and B3 are set using the difference from the power consumption upper limit value X [VA] acquired by the power suppression value acquisition unit 410Gb, such as B1 = X-30 [VA], B2 = X-80 [VA], and B3 = X-150 [VA], and the ranges of the zones A, B, and C are determined by these values. This determination result is output to the target rotation speed determination unit 410Bc of the compressor control unit 410B, and the control of the rotation speed of the compressor 14 for each of the zones A, B, and C is executed as described above.

[0073] Thereafter, in S32, it is determined whether or not F = 0. If F = 0, the determination is Yes, and the process moves to S42, which will be described later. If F = 1, the determination is No, and the process moves to S35.

[0074] In S35, the power restriction determination unit 410Ga of the power control unit 410G determines whether or not an instruction signal to end the power restriction has been input from the hot water storage control device 40. If no instruction signal has been input, the determination is No, and the process returns to the above-mentioned S5 and the same procedure is repeated, whereas if an instruction signal has been input, the determination is Yes, and the process proceeds to S40. In S40, the flag F is set to 0.

[0075] After S40, in S42, the operation mode determination unit 410Ba determines whether a predetermined boiling end condition is satisfied. The boiling end condition is, for example, whether the temperature Tw detected by the sensor 12 at a predetermined position (e.g., the lowest position) among the multiple hot water temperature sensors 12 provided in the hot water storage tank 2 is greater than the target boiling temperature Tbo. Tw≧Tbo-5[℃] (Formula 1) The state where the above condition is satisfied continues for a predetermined period (5 seconds in this example), or the inlet water temperature T1 is lower than the target boiling temperature Tbo. T1≧Tbo-5[℃] (Formula 2) has continued for a predetermined period (5 seconds in this example), etc.

[0076] If the boiling end condition is satisfied, a Yes determination is made in S42, and this flow is terminated. If the boiling end condition is not satisfied, a No determination is made in S42, and the process returns to S5 and the same procedure is repeated.

[0077] On the other hand, if the end-of-boiling condition is met in S5, that is, in the example shown in FIG. 3, if the difference between Tbo and T1 has decreased to Tbo-T1=15° C., the determination is Yes and the process proceeds to S45.

[0078] In S45, operation in the boiling end operation mode is started. That is, the operation mode determination unit 410Ba determines operation in the boiling end operation mode, and based on the determination result, the compressor 14 is controlled to the second rotation speed via the maximum rotation speed setting unit 410Bb and the target rotation speed determination unit 410Bc. In addition, the pump control unit 410F controls the rotation so that the discharge amount of the heating circulation pump 19 becomes the second flow rate.

[0079] Thereafter, in S50, it is determined whether or not F = 1. If F = 1, the determination is Yes, and the process proceeds to S60, which will be described later. If F = 0, the determination is No, and the process proceeds to S52.

[0080] In S52, the power restriction determination unit 410Ga of the power control unit 410G determines whether the power restriction signal is input from the hot water storage control device 40. If the power restriction signal is not input, the result is No and the process proceeds to S62 described below, and if the power restriction signal is input, the result is Yes and the process proceeds to S55. In S55, the flag F is set to 1.

[0081] After S55, in S60, the zone setting unit 410Gc and the boundary changing unit 410Gd of the power control unit 410G perform the zone division setting shown in Fig. 5(b). That is, in the above-mentioned example, the values ​​of B1', B2', and B3' are set using the difference from the power consumption upper limit value X [VA] acquired by the power suppression value acquisition unit 410Gb, such as B1' = X-50 [VA], B2' = X-100 [VA], and B3' = X-170 [VA], and the ranges of the zones A, B, and C are determined by these values. This determination result is output to the target rotation speed determination unit 410Bc of the compressor control unit 410B, and the control of the rotation speed of the compressor 14 for each of the zones A, B, and C is executed as described above.

[0082] Thereafter, in S62, the operation mode determination unit 410Ba determines whether the above-mentioned condition for switching from the end-of-boiling operation mode to the normal mode is satisfied based on the inlet water temperature T1 from the inlet water temperature sensor 23. In the example shown in FIG. 3, it determines whether the difference Tbo-T1 has increased to Tbo-T1=17°C. If this condition is satisfied, S62 is determined as Yes, and the process proceeds to S10 described above, and the above-mentioned processing is performed thereafter. If this condition is not satisfied, S62 is determined as No, and the process proceeds to S65.

[0083] In S65, it is determined whether F = 0. If F = 0, the determination is Yes, and the process moves to S42. If F = 1, the determination is No, and the process moves to S70.

[0084] In S70, the power restriction determination unit 410Ga of the power control unit 410G determines whether or not an instruction signal to end the power restriction has been input from the hot water storage control device 40. If no instruction signal has been input, the determination is No and the process returns to the above-mentioned S45 and the same procedure is repeated, and if the instruction signal has been input, the determination is Yes and the process proceeds to S72. In S72, the flag F is set to 0, and the process proceeds to S42.

[0085] <Effects of the embodiment> As described above, in this embodiment, in order to control the rotation speed of the compressor 14 in accordance with the power consumption upper limit value X when a power restriction signal is input, the zone setting unit 410Gc of the power control unit 410G of the heating control device 50 sets the zone A and the zones B and C shown in FIG. 5 in advance. Zone A is set as a region from the power consumption upper limit value X allowed by the power restriction signal to the power values ​​B1 and B2 that are lower than the power consumption upper limit value X. When the HP power consumption falls within zone A, the rotation speed of the compressor 14 is forcibly reduced by the control of the compressor control unit 410B. At this time, in this embodiment, the boundary change unit 410Gd can change the power values ​​B1, B2 (or B1', B2') that are the boundaries between zone A and zones B, C based on the target boiling temperature Tbo of the hot water generated in the water-refrigerant heat exchanger 15 and the inlet water temperature T1 of the hot water flowing into the water-refrigerant heat exchanger 15. As a result, when the inlet water temperature T1 of the hot water rises and the boiling is completed, the power values ​​B1, B2 are lowered to the power values ​​B1', B2', and zone A is expanded to the low power side. This expansion to the low power side causes the HP power consumption to be located in zone A at a relatively early stage, and as a result, the rotation speed of the compressor 14 is forcibly reduced at an early stage. As a result, even if there is a large change in the power consumption of the compressor 14 of the heat pump unit 3 at the time of boiling completion, the rotation speed of the compressor 14 can be quickly suppressed, and the immediate operation stop of the heat pump unit 3 due to the power supply capacity being exceeded can be avoided.

[0086] Particularly in this embodiment, zone A, zone B, and zone C are set in advance by the zone setting unit 410Gc. Zone B is set as a region ranging from power values ​​B1, B2 (or B1', B2') corresponding to the lower limit of zone A to a power value B3 (or B3') lower than that power value. When the HP power consumption falls within zone B, an increase in the rotation speed of the compressor 14 is prohibited by control of the compressor control unit 410B. In this embodiment, the boundary change unit 410Gd can change the power values ​​B1 and B2, which are the boundaries between zone A and zone B, to power values ​​B1' and B2' based on the target boiling temperature Tbo and the inlet water temperature T1. As a result, as in the above, when the boiling is completed, the power values ​​B1 and B2 are reduced to the power values ​​B1' and B2', and zone A can be expanded toward the low-power zone B side, so that the HP power consumption is located in zone A at a relatively early stage, and the forced reduction in the rotation speed of the compressor 14 is executed at an early stage. In particular, in this embodiment, the power consumption upper limit value X is located in zone B before it is in zone A, and the control to prohibit the increase in the rotation speed is executed in advance, so that the increase in the rotation speed of the compressor 14 can be more reliably avoided. As a result, even if there is a large change in the power consumption of the compressor 14 of the heat pump unit 3 at the time of the boiling completion, the rotation speed of the compressor 14 can be reliably suppressed.

[0087] Furthermore, in particular in this embodiment, as described above, when the deviation between the target boiling temperature Tbo and the inlet water temperature T1 becomes small, the boundary change unit 410Gd changes the power values ​​B1, B2 to lower values, B1', B2', and when the deviation between the target boiling temperature Tbo and the inlet water temperature T1 becomes large, the boundary change unit 410Gd changes the power values ​​B1', B2' to higher values, B1, B2. As a result, when the water has finished boiling and the inlet water temperature T1 is rising as described above, zone A can be reliably expanded to the low power side, making it possible to avoid immediate operation shutdowns due to exceeding the power supply capacity.

[0088] Furthermore, in particular in this embodiment, as described above, the boundary change unit 410Gd changes the power values ​​B1, B2 to lower power values ​​B1', B2' when the deviation between the target boiling temperature Tbo and the inlet water temperature T1 becomes equal to or less than a first predetermined value (15°C in the above example), and changes the power values ​​B1', B2' to higher power values ​​B1, B2 when the deviation between the target boiling temperature Tbo and the inlet water temperature T1 becomes equal to or greater than a second predetermined value (17°C in the above example) that is greater than the first predetermined value. In this way, by providing hysteresis when the boundary change unit 410Gd changes (switches) the power values ​​B1, B2 (or B1', B2') in accordance with the deviation between the target boiling temperature Tbo and the inlet water temperature T1, control instability such as the occurrence of hunting can be avoided and smooth control can be performed.

[0089] In particular, in this embodiment, the power values ​​applied as the zone boundaries between zones A and B as described above are different from each other when the HP power consumption increases (power values ​​B1, B1') and decreases (power values ​​B2, B2'). By providing such hysteresis, control instability such as hunting can be avoided, and smooth control can be performed.

[0090] In particular, in this embodiment, the compressor control unit 410B and the pump control unit 410F, which control the compressor 14 and the heating circulation pump 19, respectively, have a normal boiling operation mode and a boiling end operation mode as operation modes. In the boiling end operation mode, the rotation speed of the compressor 14 is controlled to a second rotation speed lower than that in the normal boiling operation mode, and the flow rate of the heating circulation pump 19 is controlled to be a flow rate higher than that in the normal boiling operation mode. Then, when the boiling end operation mode is entered, the boundary change unit 410Gd controls to lower the power values ​​B1 and B2 to power values ​​B1' and B2' to expand zone A to the low power side. This makes it possible to reliably suppress the rotation speed of the compressor 14 when there is a large change in power consumption at the time of boiling end.

[0091] Furthermore, particularly in this embodiment, the zone setting unit 410Gc sets the power values ​​B1, B2 (or B1', B2') based on the difference from the corresponding power consumption upper limit value X, and the boundary changing unit 410Gd changes the power values ​​B1, B2 to lower power values ​​B1', B2' by changing the difference to a larger value when Tbo-T1 becomes small, and changes the power values ​​B1', B2' to higher power values ​​B1, B2 by changing the difference to a smaller value when Tbo-T1 becomes large. This makes it possible to ensure that the difference between the power values ​​B1, B2 (or B1', B2') and the corresponding power consumption upper limit value X is equal to or greater than a predetermined value, regardless of the value of the power consumption upper limit value X, unlike, for example, when the power values ​​B1, B2 (or B1', B2') are regulated by a ratio with the corresponding power consumption upper limit value X. As a result, when the water has finished boiling, the HP power consumption is reliably positioned within zone A at an early stage, and the rotation speed of compressor 14 can be reliably and forcibly reduced at an early stage.

[0092] In the above, the heat pump cycle may be an ejector cycle using an ejector as a pressure reducer.

[0093] In the above description, the heat source unit is an air-source heat pump having an outdoor fan 67 that blows outside air while passing a refrigerant through the air heat exchanger 17 as a heat source-side heat exchanger, and heat is exchanged between the outside air as a heat source and the refrigerant, but the present invention is not limited to this. That is, the heat source unit may be configured such that water or antifreeze liquid is supplied to the heat source-side heat exchanger, and the liquid and the refrigerant exchange heat in the heat source-side heat exchanger. In addition, a heat source side heat exchanger may be provided underground or in a relatively large-capacity water source, and the heat source side heat exchanger may exchange heat between the refrigerant and the underground or water source. Furthermore, a composite heat source type may be configured with a heat pump circuit using heat from the underground or water source and another heat pump circuit using air heat. Furthermore, in place of the liquid, the outside air, or the water source, other materials (for example, gases including smoke, exhaust fumes, and various high-temperature gases, or fluid solids including hot sand, dust, and various particles) may be passed through the heat source side heat exchanger as long as they are capable of exchanging heat with the refrigerant in the heat source side heat exchanger, or heat from sunlight, reflected light, and other radiation may be supplied to the heat source side heat exchanger.

[0094] In the above, the arrows shown in each figure such as FIG. 2 show an example of the flow of signals, and do not limit the direction of the signal flow.

[0095] Furthermore, the flowchart shown in FIG. 6 does not limit the present invention to the procedures shown in the above flow, and procedures may be added or deleted or the order of procedures may be changed without departing from the spirit and technical concept of the invention.

[0096] In addition to the above, the methods according to the above embodiments and their modifications may be used in appropriate combination.

[0097] Although not specifically illustrated, the present invention can be implemented with various modifications without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0098] 1 Tank Unit 2 Hot water tank 3. Heat pump unit (heat pump water heater) 4 Heating circulation circuit (hot water circulation circuit) 5. Heated feed pipe 6 Heat return pipe 14 Compressor 15 Water-refrigerant heat exchanger 16 Electronic expansion valve (expansion valve) 17 Air heat exchanger 18 Refrigerant piping 19 Heating circulation pump (circulation pump) 22 Outside air temperature sensor (outside air temperature detection means) 23 Inlet water temperature sensor (inlet water temperature detection means) 24 Boiling temperature sensor (hot water temperature detection means) 30 Refrigerant circulation circuit 40 Hot water storage control device 50 Heating control device 410A Operation switching unit 410Aa Operation information output section 410B Compressor control section (compressor control means) 410Ba Operation mode determination unit 410F Pump control section (pump control means) 410G Power Control Unit 410Ga Power Suppression Judgment Unit (Power Suppression Judgment Means) 410Gb power suppression value acquisition unit (power suppression value acquisition means) 410Gc Zone setting unit (zone setting means) 410Gd Boundary change unit (boundary setting means) Tair Outside temperature Tbo Target boiling temperature (target hot water temperature) T1 Inlet water temperature

Claims

1. A heat pump device in which a compressor, an expansion valve, and an air heat exchanger are connected by refrigerant piping; A water-refrigerant heat exchanger that receives a refrigerant from the heat pump device through the refrigerant piping and generates hot water for the hot water circulation circuit side by heat exchange with water; A circulation pump that circulates the hot water generated in the water-refrigerant heat exchanger; a power reduction determination means for determining whether a power reduction signal instructing reduction of power consumption in the heat pump device has been input; a compressor control means for increasing or decreasing a rotation speed of the compressor when it is determined that the power restriction signal has been inputted by the power restriction determination means so that the rotation speed of the compressor becomes a target compressor rotation speed corresponding to a power consumption upper limit value allowed by the power restriction signal; a zone setting means for setting a first control zone, which is a zone from the power consumption upper limit value to a first power suppression target value lower than the power consumption upper limit value, and a second control zone, which is a zone on the lower power side than the first control zone, the first control zone being defined in order to control a rotation speed of the compressor in response to an actual power consumption value in the heat pump device; having The compressor control means When the actual power consumption value is within the first control zone, a control is performed to forcibly reduce a rotation speed of the compressor. The water-refrigerant heat exchanger includes a boundary change means for changing the first power suppression target value, which is a boundary between the first control zone and the second control zone, based on a target hot water temperature of the hot water generated in the water-refrigerant heat exchanger and an inlet water temperature of the hot water flowing into the water-refrigerant heat exchanger. A heat pump water heater characterized by the above.

2. The second control zone is a third control zone that is an area lower than the first power suppression target value and up to a second power suppression target value that is lower than the first power suppression target value, and a fourth control zone that is an area on the lower power side than the second power suppression target value, The compressor control means When the actual power consumption value is within the third control zone, a control is performed to prohibit an increase in the rotation speed of the compressor. The boundary changing means is The first power suppression target value, which is the boundary between the first control zone and the third control zone, is changed based on the target hot water temperature and the inlet water temperature, and the second power suppression target value, which is the boundary between the third control zone and the fourth control zone, is changed.

2. The heat pump water heater according to claim 1.

3. The boundary changing means is When the deviation between the target hot water temperature and the inlet water temperature becomes small, the first power suppression target value is changed to a lower value, When the deviation between the target hot water temperature and the inlet water temperature becomes large, the first power suppression target value is changed to a higher value.

3. The heat pump water heater according to claim 1 or 2.

4. The boundary changing means is When a deviation between the target hot water temperature and the inlet water temperature becomes equal to or smaller than a first predetermined value, the first power suppression target value is changed to a lower value, When the deviation between the target hot water temperature and the inlet water temperature becomes equal to or greater than a second predetermined value that is greater than the first predetermined value, the first power suppression target value is changed to a higher value.

4. The heat pump water heater according to claim 3.

5. The zone setting means includes: The first power suppression target value that is applied when the actual power consumption value increases and the first power suppression target value that is applied when the actual power consumption value decreases are set to be different values ​​from each other.

4. The heat pump water heater according to claim 3.

6. an inlet water temperature detection means for detecting the inlet water temperature; A hot water temperature detection means for detecting the temperature of hot water generated in the water-refrigerant heat exchanger in the hot water circulation circuit; A pump control means for controlling the circulation pump; and The compressor control means and the pump control means a normal boiling operation mode in which the compressor is controlled to a predetermined first rotation speed and the flow rate of the circulation pump is controlled so that the hot water temperature detected by the hot water temperature detection means becomes the target hot water temperature, or a boiling end operation mode in which, in the normal boiling operation mode, when the inlet water temperature detected by the inlet water temperature detection means satisfies a predetermined temperature condition before the end of boiling, the compressor is controlled to a second rotation speed which is smaller than the first rotation speed and the flow rate of the circulation pump is controlled to a flow rate which is larger than that in the normal boiling operation mode, The boundary changing means is When the operation mode is the end-of-boiling operation mode, the first power suppression target value is changed.

4. The heat pump water heater according to claim 3.

7. The zone setting means includes: The first power suppression target value is set based on a difference between the first power suppression target value and a corresponding power consumption upper limit value, The boundary changing means is When the deviation between the target hot water temperature and the inlet water temperature becomes small, the difference is changed to a larger value, thereby changing the first power suppression target value to a lower value; When the deviation between the target hot water temperature and the inlet water temperature becomes large, the difference is changed to a smaller value, thereby changing the first power suppression target value to a higher value.

4. The heat pump water heater according to claim 3.

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