Heat pump hot water heat source machine

Abstract

To sufficiently melt frost adhered even when frost formation occurs in an air heat exchanger during electric power suppression control.SOLUTION: A heat pump unit 3 includes: a start determination section 410Ad that determines whether or not a predetermined defrosting start condition is satisfied during a boiling-up operation; and a pump control section 410F and a compressor control section 410B that start a defrosting operation of an air heat exchanger 17 after the satisfaction of the defrosting start condition is determined. In accordance with a determination result from an electric power suppression determination section 410Ga, a condition switching section 410Ag switches which one of a first defrosting start condition where elapsed time after start of execution of the boiling-up operation is a predetermined threshold value or larger or a second defrosting start condition including a state where an outside air temperature Tair is within a predetermined temperature range is applied. Due to this configuration, when the electric power suppression control is being performed, triggered by elapse of time to some extent after the start of the execution of the boiling-up operation, start of the defrosting operation is enabled, regardless of whether or not the second defrosting start condition is satisfied in S16.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Conventionally, in this type of heat pump hot water heat source machine, 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] When power consumption is suppressed as in the conventional system described above, power suppression control is usually performed so that the power consumption of the heat pump device is within an upper limit value, and the compressor rotation speed is limited. If frost forms on the heat source side heat exchanger of the heat pump device during such power suppression control, even if a defrosting operation is performed to remove the frost, there is a problem that the frost on the heat exchanger may not be sufficiently melted because the compressor rotation speed is kept low. [Means for solving the problem]

[0005] In order to solve the above problem, in claim 1 of the present invention, there is provided a heat pump device having a compressor, a pressure reducer, and an air heat exchanger connected by refrigerant piping, a water-refrigerant heat exchanger that receives refrigerant from the heat pump device through the refrigerant piping and generates hot water for a hot water circulation circuit side by heat exchange with water, a 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, a 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 an outside air temperature detection means that detects an outside air temperature, and the heat received from the refrigerant in the water-refrigerant heat exchanger is used. The heat pump hot water heat source machine performs a boiling operation to generate hot water on the hot water circulation circuit side by using a start determination means for determining whether a predetermined defrost start condition is satisfied during the boiling operation, a defrost start control means for starting a defrosting operation of the air heat exchanger by using heat received by a refrigerant in the water-refrigerant heat exchanger after the start determination means determines that the defrost start condition is satisfied, and a condition switching means for switching, depending on a determination result of the power suppression determination means, whether to apply, as a determination criterion for the start determination means, either a first defrost start condition in which the elapsed time since the start of execution of the boiling operation is equal to or greater than a predetermined threshold, or a second defrost start condition including that the outside air temperature detected by the outside air temperature detection means is within a predetermined temperature range.

[0006] In addition, in claim 2, the power restriction determination means further has a power restriction value acquisition means for acquiring a power consumption suppression value indicated by the power restriction signal when the power restriction determination means determines that the power restriction signal has been input, and the condition switching means performs the switching depending on the determination result of the power restriction determination means and the suppression value acquired by the power restriction value acquisition means.

[0007] In addition, in claim 3, the power suppression device further comprises a threshold setting means for switching and setting the threshold value according to the suppression value acquired by the power suppression value acquisition means.

[0008] In addition, in claim 4, the system further includes an end determination means for determining whether a predetermined defrost end condition is satisfied after the defrost start control means has started the defrost operation, and a boiling control means for resuming the boiling operation when the end determination means determines that the defrost end condition is satisfied, and the defrost end condition is a common condition regardless of whether the condition switching means switches to either the first defrost start condition or the second defrost start condition to start the defrost operation. Effect of the Invention

[0009] According to claim 1 of this invention, during boiling operation, the water-refrigerant heat exchanger functions as a condenser, and hot water is generated on the hot water circulation circuit side using heat received from the refrigerant (=boiling operation). During boiling operation, the air heat exchanger functions as an evaporator, so frost may form over the course of operation, in which case a defrosting operation is performed. During defrosting operation, the frost that has formed on the air heat exchanger is melted and defrosted by the heat of the refrigerant heated by compression in the compressor.

[0010] Here, when power suppression control is being performed, the compressor rotation speed is kept low when the defrosting operation is performed, so there is a possibility that the frost adhering to the air heat exchanger may not be melted sufficiently. Therefore, the present invention includes a power suppression determination means for determining whether or not a power suppression signal instructing suppression of power consumption in the heat pump device has been input, and a condition switching means for switching a defrost start condition depending on a determination result of the power suppression determination means. When the start determination means determines whether or not the defrost start condition is satisfied during the boiling operation, the condition switching means switches between applying either a first defrost start condition in which the elapsed time since the start of the boiling operation is equal to or greater than a predetermined threshold, and a second defrost start condition in which the outside air temperature is within a predetermined temperature range.

[0011] This makes it possible to apply the second defrost start condition when the power suppression signal is not input, and to apply the first defrost start condition when the power suppression signal is input. As a result, when the power suppression control is being performed, it becomes possible to start the defrost operation when a certain amount of time has elapsed since the start of the boiling operation, regardless of whether the second defrost start condition is satisfied. Therefore, even if it is expected that the frost cannot be sufficiently melted if the boiling operation is continued until the second defrost start condition is satisfied due to the influence of the power suppression control, the defrost operation can be started at a timing earlier than the second defrost start condition is satisfied, so that the frost attached to the air heat exchanger can be sufficiently melted and removed.

[0012] According to claim 2, when a power restriction signal is input, a power consumption restriction value instructed by the power restriction signal is acquired, and the condition switching means switches the defrost start condition taking the restriction value into consideration. This allows for detailed defrost start control to be performed according to the level of the compressor's capacity during power restriction control, and ensures that the frost adhering to the air heat exchanger is melted.

[0013] According to claim 3, when a power restriction signal is input, the threshold value serving as the first defrost start condition is variably set according to the power consumption restriction value instructed by the power restriction signal. This allows for more detailed defrost start control to be executed according to the level of the compressor capacity during power restriction control, and makes it possible to more reliably melt the frost adhering to the air heat exchanger.

[0014] According to claim 4, when a predetermined defrost end condition is satisfied, the defrosting operation ends and the operation returns to the boiling operation. The defrost end condition at this time is common regardless of whether the defrost start condition is the first or second defrost start condition. Even if the conditions at the start of the defrosting operation are different, the conditions at the end of the defrosting operation are common, making it possible to smoothen and simplify the control. [Brief description of the drawings]

[0015] [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] A flowchart showing a control procedure executed by the operation switching unit. [Figure 4] A functional block diagram showing the functional configuration of a heating control device in a modified example in which a threshold value is changed according to an upper power limit value. [Diagram 5] A flowchart showing a control procedure executed by the operation switching unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Next, an embodiment of the present invention will be described with reference to the drawings.

[0017] <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 heat source device).

[0018] The heat pump unit 3 includes a water-refrigerant heat exchanger 15 and a heating circulation pump 19 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 as hot water piping, 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.

[0019] The heating supply 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 midway along the heating supply pipe 5, and circulates the hot water in the hot water storage tank 2 while circulating the hot water from the heating supply pipe 5 to the heating return pipe 6 via the water-side flow path 15a. The heating return pipe 6 is provided with a boiling temperature sensor 24 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] In the refrigerant circulation circuit 30, for example, R32 refrigerant is used as a refrigerant, forming a heat pump cycle. A discharge temperature sensor 20 is provided at the discharge side of the compressor 14 of the refrigerant piping 18 to detect a refrigerant discharge temperature Tout of the refrigerant discharged from the compressor 14, and an outside air temperature sensor 22 (corresponding to an outside air temperature detection means) is provided at the air inlet side of the air heat exchanger 17 to detect an outside air temperature Tair. In addition, a refrigerant temperature sensor 52 is provided at the refrigerant piping 18 midway through the air heat exchanger 17 to detect a refrigerant temperature Tc on the low pressure side. In this embodiment, the temperature detected by the refrigerant temperature sensor 52 essentially functions as the refrigerant temperature Tc in the air heat exchanger 17.

[0025] 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, 24, and 52 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 coordinating with each other based on the detection results of the sensors 24, 12, 11, 20, 22, and 52, etc.

[0026] 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, where, for example, the hot water control device 40 outputs 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 controls 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 the sensors 20, 22, 24, 52. In the following, this specification will be described taking such a case as an example.

[0027] <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.

[0028] 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 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.

[0029] <Heating control device> Next, the heating control device 50 provided in the heat pump unit 3 will be described. 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.

[0030] 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, and a power control unit 410G.

[0031] 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 to actually perform a boiling operation or a defrosting operation in the heat pump unit 3 according 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 to perform the boiling operation or the defrosting operation) to the compressor control unit 410B, the expansion valve control unit 410C, the outdoor fan control unit 410D, and the pump control unit 410F. 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 determined appropriately. The end determination unit 410Ac, the start determination unit 410Ad, the timer unit 410Ae, the threshold setting unit 410Af, and the condition switching unit 410Ag will be described later.

[0032] In this example, the outside air temperature Tair detected by the outside air temperature sensor 22 and the operation information corresponding to the operation command of the hot water storage control device 40 are input to the compressor control unit 410B (this may be input directly or indirectly; the same applies below). The compressor control unit 410B also receives a determination result from a power suppression determination unit 410Ga, which will be described later, and a current suppression value from a power suppression value acquisition unit 410Gb. The compressor control unit 410B has a maximum rotation speed setting unit 410Bb and a target rotation speed determination unit 410Bc.

[0033] 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 a predetermined condition. The target rotation speed determination unit 410Bc sets a target rotation speed of the compressor 14 within the range of the set maximum target rotation speed based on the input outside air temperature Tair, the target boiling temperature Tbo, the power suppression signal, and the judgment result of the power suppression judgment unit 410Ga, 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).

[0034] 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.

[0035] 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 controls the rotation speed of the outdoor fan 67 based on the input operation information and the outdoor air temperature Tair.

[0036] The pump control unit 410F receives the boiling temperature Tb detected by the boiling temperature sensor 24 and the operating information 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. The power control unit 410G will be described later.

[0037] <Boiling operation> 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).

[0038] <Defrost start conditions> As the boiling operation is performed as described above and the refrigerant circulates in the refrigerant pipe 18 connecting the compressor 14, the water-refrigerant heat exchanger 15, the electronic expansion valve 16, and the air heat exchanger 17, frost may form in the air heat exchanger 17. In this embodiment, when the frost has progressed to a certain extent and a predetermined defrosting start condition is established, the operation switching unit 410A of the heating control device 50 interrupts the boiling operation and performs a positive cycle defrosting operation. That is, the boiling operation is switched to the positive cycle defrosting operation by the control of the compressor control unit 410B, the expansion valve control unit 410C, the outdoor fan control unit 410D, and the pump control unit 410F based on the operation information from the operation information output unit 410Aa of the operation switching unit 410A. That is, the operation switching unit 410A determines whether or not to switch from the boiling operation to the defrosting operation depending on whether the defrosting start condition is established during the boiling operation. The operation information output from the operation information output unit 410Aa includes information on whether or not a boiling operation is to be performed and whether or not a defrosting operation is to be performed.

[0039] As the defrost start condition, for example, the outside air temperature Tair detected by the outside air temperature sensor 22 is within a predetermined range (for example, -10°C or higher and less than 2°C), and the temperature difference Tair - Tc obtained by subtracting the refrigerant temperature Tc in the air heat exchanger 17 detected by the refrigerant temperature sensor 52 from the outside air temperature Tair is within a predetermined range (for example, greater than 8°C). That is, when the outside air temperature Tair is considerably low and the refrigerant temperature Tc in the air heat exchanger 17 is considerably lower than the outside air temperature Tair, it is estimated that the frost accumulation amount is so large that defrosting is necessary. The outside air temperature Tair and the refrigerant temperature Tc are input to the operation switching unit 410A, and based on them, the operation switching unit 410A determines whether or not the defrost start condition is satisfied.

[0040] <Positive cycle defrost operation> In the positive cycle defrost operation, in a state where the boiling-up operation is stopped (a state where the heating circulation pump 19 is substantially stopped under the control of the pump control unit 410F), the expansion valve control unit 410C opens the electronic expansion valve 16 more than during the boiling-up operation, and the refrigerant circulates in the same direction as during the boiling-up operation, that is, in the direction of compressor 14 → water-refrigerant heat exchanger 15 → electronic expansion valve 16 → air heat exchanger 17 → compressor 14. As a result, the refrigerant heated by compression in the compressor 14 is supplied to the air heat exchanger 17 via the refrigerant pipe 18, and the air heat exchanger 17 is defrosted by heating the refrigerant. Note that the "state where the heating circulation pump 19 is substantially stopped" specifically means a state where the heating circulation pump 19 is stopped under the control of the pump control unit 410F, or a state where the heating circulation pump 19 is driven continuously or intermittently at a rotation speed significantly lower than the rotation speed during the boiling-up operation under the control of the pump control unit 410F.

[0041] <Power saving control> Here, 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 operation switching unit 410A and 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.

[0042] At this time, as described above, the heating control device 50 is provided with a power control unit 410G. In this example, the power control unit 410G receives a power reduction signal from the hot water storage control device 40 and HP power consumption from the heat pump power consumption detection device 200. The power control unit 410G also has a power reduction determination unit 410Ga (corresponding to a power reduction determination means) and a power reduction value acquisition unit 410Gb (corresponding to a power reduction value acquisition means).

[0043] The power restriction determination unit 410Ga determines whether 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 and a condition switching unit 410Ag of the operation switching unit 410A described later. 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 value (corresponding to the power consumption restriction value) 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 condition switching unit 410Ag of the operation switching unit 410A described later.

[0044] 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.

[0045] <Possible impacts of power suppression control> As described above, when power restriction control is performed, the compressor control unit 410B restricts the rotation speed of the compressor 14 so that the HP power consumption is within the power consumption upper limit. For example, if frost forms on the air heat exchanger 17 of the heat pump unit 3 during such power restriction control, even if the positive cycle defrosting operation is performed to remove the attached frost, the rotation speed of the compressor 14 is kept low, and the amount of heat generated in the air heat exchanger 17 is insufficient, so that the frost attached to the air heat exchanger 17 may not be melted sufficiently.

[0046] Therefore, in this embodiment, in addition to the driving information output unit 410Aa, the driving switching unit 410A is provided with an end determination unit 410Ac (corresponding to an end determination means), a start determination unit 410Ad (corresponding to an start determination means), a timing unit 410Ae, and a condition switching unit 410Ag (corresponding to a condition switching means).

[0047] The start determination unit 410Ad determines whether or not a predetermined defrost start condition is satisfied during the boiling operation. When the start determination unit 410Ad determines that the defrost start condition is satisfied, the operation information output unit 410Aa outputs the operation information indicating that the defrost operation is to be performed, thereby starting the defrost operation of the air heat exchanger 17.

[0048] At this time, a condition switching unit 410Ag switches the defrost start condition, which is the judgment criterion in the start judgment unit 410Ad, between a first defrost start condition and a second defrost start condition according to the judgment result of the power suppression judgment unit 410Ga of the power control unit 410G and the power suppression value acquired by the power suppression value acquisition unit (details will be described later). A timing unit 410Ae functions as a timer for counting time.

[0049] Then, after the defrosting operation is started, the termination determination unit 410Ac determines whether or not a predetermined defrost termination condition (described in detail later) is satisfied, and if it is determined that the defrosting termination condition is satisfied, the operation information output unit 410Aa outputs the operation information indicating that boiling operation will be performed, thereby resuming the boiling operation.

[0050] <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.

[0051] 3, first, in S2, the operation information output unit 410Aa of the operation switching unit 410A determines whether or not an operation command to perform a boiling operation has been received from the hot water storage control device 40. If the operation command has been received, the determination is Yes, and the process proceeds to S4.

[0052] In S4, the compressor control unit 410B starts the compressor 14 to start the boiling operation. Then, in S5, the target rotation speed determination unit 410Bc of the compressor control unit 410B starts temperature adjustment control of the rotation speed of the compressor 14. Then, the process proceeds to S6.

[0053] In S6, the condition switching unit 410Ag of the operation switching unit 410A judges whether or not the power suppression signal has been input from the hot water storage control device 40 based on the judgment result from the power suppression judgment unit 410Ga of the power control unit 410G. If the power suppression signal has not been input, the judgment is No and the process moves to S16 described below, and if the power suppression signal has been input, the judgment is Yes and the process moves to S7.

[0054] In S7, the power suppression value acquisition unit 410Gb of the power control unit 410G determines whether the outside air temperature Tair detected by the outside air temperature sensor 22 is a predetermined temperature, in this example, 0° C. or less. If Tair>0° C., the result is No and the process moves to S16 described below, and if Tair≦0° C., the result is Yes and the process moves to S10.

[0055] In S10, the condition switching unit 410Ag of the operation switching unit 410A determines whether the power consumption upper limit value represented by the power suppression signal is a predetermined value, in this example, 500VA or less, based on the acquisition result from the power suppression value acquisition unit 410Gb of the power control unit 410G. If it exceeds 500VA, S10 is determined as No and the process moves to S16 described below. If it is 500VA or less, the process moves to S11, and the threshold setting unit 410Af of the operation switching unit 410A sets the elapsed time threshold T used in S14 described below to a predetermined time, in this example, 30 minutes. After S11, the process moves to S14.

[0056] In S14, the start determination unit 410Ad of the operation switching unit 410A determines whether or not the elapsed time after the start of the boiling operation in S4 (specifically, the elapsed time from the start of the temperature adjustment control execution in S5) is equal to or greater than the threshold value T defined in S11 above, based on the counting result in the timer unit 410Ae. While the elapsed time is less than the threshold value T, S14 is determined as No, and when the elapsed time is equal to or greater than the threshold value T, S14 is determined as Yes, and the process proceeds to S20 described below. Note that the fact that the elapsed time is equal to or greater than the threshold value T corresponds to a first defrost start condition.

[0057] On the other hand, in S16, which is entered after a No judgment is made in S6, S7, or S10, the start judgment unit 410Ad of the operation switching unit 410A judges whether a predetermined defrost start temperature condition is satisfied. This defrost start temperature condition is an index for judging whether frost has formed in the air heat exchanger 17 during the boiling operation and defrosting is necessary (corresponding to a second defrost start condition). For example, the defrost start temperature condition is defined based on the outdoor air temperature Tair detected by the outdoor air temperature sensor 22 and the refrigerant temperature Tc in the air heat exchanger 17 detected by the refrigerant temperature sensor 52. In detail, as described above, the condition is that the outdoor air temperature Tair is within a predetermined range (for example, -10°C or more and less than 2°C) and the temperature difference Tair-Tc obtained by subtracting the refrigerant temperature Tc from the outdoor air temperature Tair is within a predetermined range (for example, greater than 8°C). If the defrost start temperature condition is not satisfied in S16, a No judgment is made and the process returns to S5 and the above-mentioned processing is repeated. If the defrost start temperature condition is satisfied in S16, a Yes judgment is made and the process proceeds to S20.

[0058] In S20, the heating circulation pump 19 is substantially stopped by the control of the pump control unit 410F, and the above-mentioned positive cycle defrosting operation is started. The pump control unit 410F that executes S20 and the compressor control unit 410B that executes S20 function as a defrosting start control means.

[0059] Thereafter, in S30, the end determination unit 410Ac of the operation switching unit 410A determines whether a predetermined defrost end condition is satisfied. The defrost end condition is an index for determining whether the frost in the air heat exchanger 17 is sufficiently melted and the defrost is completed during the defrosting operation. For example, the defrost end condition is defined based on the refrigerant temperature Tc in the air heat exchanger 17 detected by the refrigerant temperature sensor 52. In detail, the condition is that the refrigerant temperature Tc in the air heat exchanger 17 continues to be a predetermined value (e.g., 8°C) or higher for a certain period (e.g., about 60 seconds) or more. This is because, when this condition is satisfied, it is estimated that the frost in the air heat exchanger 17 is sufficiently melted and the defrost is completed. As shown in FIG. 3, in the determination in S30, a common defrost end condition is applied whether the first defrost start condition is satisfied in S14 and the defrosting operation is started, or the second defrost start condition is satisfied in S16 and the defrosting operation is started.

[0060] In S30, if the defrosting end condition is satisfied, a Yes is determined, and the process proceeds to S35. In S35, the heating circulation pump 19 is started to be driven under the control of the pump control unit 410F, and the defrosting operation is ended. After that, in S50, the boiling operation described above is resumed. The compressor control unit 410B that executes S50 functions as a boiling control unit. After that, the process proceeds to S80.

[0061] In S80, the operation information output unit 410Aa of the operation switching unit 410A judges whether or not there is an operation command from the hot water storage control device 40 to instruct the end of the boiling operation. If there is no operation command, S80 is judged as No, and the process returns to S5 and the same procedure is repeated. If there is an operation command, it is judged as Yes, and the process proceeds to S85.

[0062] In S85, the compressor control unit 410B stops driving the compressor 14 to stop the boiling operation, and this flow is ended.

[0063] <Effects of the embodiment> As described above, in this embodiment, during boiling operation, the water-refrigerant heat exchanger 15 functions as a condenser, and hot water is generated on the heating circulation circuit 4 side by using heat received from the refrigerant (=boiling operation). During boiling operation, the air heat exchanger 17 functions as an evaporator, so frost may form over the course of operation, in which case a positive cycle defrosting operation is performed. That is, the heating circulation pump 19 is substantially stopped by the control of the pump control unit 410F, and the frost attached to the air heat exchanger 17 is melted by heat due to the heating of the refrigerant heated by compression in the compressor 14, and defrosted. Here, when power reduction control is being performed, the rotation speed of the compressor 14 is kept low when the above-mentioned defrosting operation is performed, so that the frost adhering to the air heat exchanger 17 may not be melted sufficiently.

[0064] Therefore, in this embodiment, a power reduction determination unit 410Ga that determines whether or not a power reduction signal instructing reduction of power consumption in the heat pump unit 3 has been input, and a condition switching unit 410Ag that switches the defrost start condition according to the determination result of the power reduction determination unit 410Ga are provided. When the start determination unit 410Ad determines whether or not the defrost start condition is satisfied during the boiling operation, the condition switching unit 410Ag switches between the first defrost start condition (see S11 and S14 in FIG. 3) in which the elapsed time after the start of the boiling operation is equal to or greater than a predetermined threshold, and the second defrost start condition (see S16 in FIG. 3) in which the outside air temperature Tair is within a predetermined temperature range.

[0065] As a result, when the power suppression signal is not input, the second defrost start condition is applied in S16, whereas when the power suppression signal is input, the first defrost start condition is applied in S11 and S14. As a result, when the power suppression control is being performed, it is possible to start the defrosting operation when a certain amount of time has elapsed since the start of the boiling operation, regardless of whether the second defrost start condition in S16 is satisfied. Therefore, even if it is expected that the frost cannot be sufficiently melted if the boiling operation is continued until the second defrost start condition is satisfied due to the influence of the power suppression control, the defrosting operation can be started at a timing earlier than the second defrost start condition is satisfied, so that the frost adhering to the air heat exchanger 17 can be sufficiently melted and removed.

[0066] Furthermore, particularly in this embodiment, when a power restriction signal is input, the power consumption upper limit value instructed by the power restriction signal is acquired by the power restriction value acquisition unit 410Gb, and the condition switching unit 410Ag switches the defrost start condition taking into account the upper limit value (see S10 in FIG. 3). This allows for detailed defrost start control to be executed according to the level of capacity of the compressor 14 during power restriction control, and the frost adhering to the air heat exchanger 17 to be reliably melted.

[0067] Furthermore, particularly in this embodiment, when a predetermined defrost end condition is satisfied (see S30 in FIG. 3), the defrosting operation ends and the operation returns to the boiling operation (see S35, S50 in FIG. 3). The defrost end condition at this time is common regardless of whether the defrost start condition is the first defrost start condition in S11, S14 or the second defrost start condition in S16. By making the condition at the end of the defrosting operation common even if the condition at the start of the defrosting operation is different, smoother and simpler control can be achieved.

[0068] The present invention is not limited to the above-mentioned embodiment, and can be applied within the scope of the present invention. Such modified examples will be described below.

[0069] (1) Changing the threshold T according to the power upper limit A functional block diagram showing the functional configuration of the heating control device of this modified example is shown in Fig. 4. As shown in the figure, in this modified example, a threshold setting unit 410Af (corresponding to a threshold setting means) is newly provided in the operation switching unit 410A. In this modified example, the threshold setting unit 410Af switches and sets the threshold according to the power suppression value acquired by the power suppression value acquisition unit 410Gb (details will be described later).

[0070] A flowchart showing the control procedure executed by the heating control device 50 of this modified example is shown in Fig. 5. In this modified example, S8 is provided between S7 and S10 in Fig. 5. If the outside air temperature Tair is greater than 0°C in S7, a No decision is made and the process moves to S16 as described above, and if Tair 0°C or less, a Yes decision is made and the process moves to the newly provided S8.

[0071] In S8, the condition switching unit 410Ag of the operation switching unit 410A judges whether the power consumption upper limit value represented by the power suppression signal is equal to or less than a first predetermined value, in this example, 800 VA, based on the result of acquisition from the power suppression value acquisition unit 410Gb of the power control unit 410G. If it exceeds 800 VA, the result is No and the process proceeds to S16, whereas if it is equal to or less than 800 VA, the result is Yes and the process proceeds to S10' which is similar to S10.

[0072] In S10', the condition switching unit 410Ag of the operation switching unit 410A judges whether the power consumption upper limit value represented by the power suppression signal is equal to or less than a second predetermined value, 500VA in this example, based on the result of acquisition from the power suppression value acquisition unit 410Gb of the power control unit 410G. If it is equal to or less than 500VA, a Yes judgment is made and the process proceeds to a newly provided S11, and the threshold setting unit 410Af of the operation switching unit 410A sets the threshold T of the elapsed time used in the S14 to the first hour, 30 minutes in this example. If it exceeds 500VA, a No judgment is made in S10' and the process proceeds to a newly provided S12, and the threshold setting unit 410Af of the operation switching unit 410A sets the threshold T of the elapsed time used in the S14 to the second hour, 40 minutes in this example. After S11 and S12, the process proceeds to S14.

[0073] The other processing steps are the same as those in the previous embodiment, and therefore the description thereof will be omitted.

[0074] In this modified example, the same effects as those of the above embodiment are obtained. In this modification, when a power restriction signal is input, the threshold value serving as the first defrost start condition is variably set by the threshold setting unit 410Af according to the upper limit of power consumption indicated by the power restriction signal (see S11 and S12 in FIG. 5). This allows for more detailed defrost start control to be executed according to the level of capacity of the compressor 14 during power restriction control, thereby making it possible to more reliably melt the frost adhering to the air heat exchanger 17.

[0075] (2)Other In the above, the hot water storage tank 2 is connected to the load side of the water-refrigerant heat exchanger 15 via the heating circulation circuit 4 consisting of the heating forward pipe 5 and the heating return pipe 6, and the hot water generated in the water-refrigerant heat exchanger 15 is supplied to the hot water storage tank 2 to perform the boiling operation, but the present invention is not limited to this. That is, a heating operation may be performed as a hot water generating operation in which appropriate heat exchange terminals such as a fan coil, a floor heating panel, a panel convector, etc. are connected via a circulation circuit that circulates hot water similar to the heating circulation circuit 4, and hot water is supplied to the heat exchange terminals to perform heating. In this case, the same effect can be obtained by the same method as described above.

[0076] The heat pump cycle may be an ejector cycle using an ejector as a pressure reducer.

[0077] 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.

[0078] In the above, the arrows shown in each of the drawings such as FIG. 2 and FIG. 4 show an example of the flow of signals, and do not limit the direction of the signal flow.

[0079] Furthermore, the flowcharts shown in Figures 3 and 5 do not limit the present invention to the procedures shown in the above flows, and steps may be added or deleted, or the order of steps may be changed, etc., within the scope that does not deviate from the spirit and technical concept of the invention.

[0080] In addition to the above, the methods according to the above embodiments and their modifications may be used in appropriate combination.

[0081] 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]

[0082] 1 Tank Unit 2 Hot water tank 3. Heat pump unit (heat pump hot water source unit) 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 (pressure reducer) 17 Air heat exchanger 18 Refrigerant piping 22 Outside air temperature sensor (outside air temperature detection means) 30 Refrigerant circulation circuit 40 Hot water storage control device 50 Heating control device 52 Refrigerant temperature sensor 410A Operation Switching Unit 410Aa Operation information output section 410Ac End determination unit (end determination means) 410Ad Start determination section (start determination means) 410Af Threshold setting unit (threshold setting means) 410Ag Condition switching unit (condition switching means) 410B Compressor control section (compressor 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) Tair Outside temperature Tc Refrigerant temperature

Claims

1. A heat pump device in which a compressor, a pressure reducer, 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 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; An outside air temperature detection means for detecting an outside air temperature; having In a heat pump hot water heat source machine that performs a boiling operation to generate hot water on the hot water circulation circuit side by using heat received from a refrigerant in the water-refrigerant heat exchanger, A start determination means for determining whether a predetermined defrost start condition is satisfied during the boiling operation; A defrost start control means for starting a defrosting operation of the air heat exchanger by using heat received by the refrigerant in the water-refrigerant heat exchanger after the start determination means determines that the defrost start condition is satisfied; a condition switching means for switching, as a judgment criterion in the start judgment means, whether to apply a first defrost start condition in which the elapsed time since the start of the boiling operation is equal to or longer than a predetermined threshold value, or a second defrost start condition including that the outside air temperature detected by the outside air temperature detection means is within a predetermined temperature range, depending on a judgment result of the power suppression judgment means; A heat pump hot water heat source machine comprising:

2. a power restriction value acquisition unit that acquires a power restriction value of power consumption instructed by the power restriction signal when the power restriction determination unit determines that the power restriction signal has been input; The condition switching means is The switching is performed according to a determination result of the power restriction determination means and the restriction value acquired by the power restriction value acquisition means.

2. The heat pump hot water heat source device according to claim 1.

3. The power control unit further includes a threshold setting unit that switches and sets the threshold value according to the power control value acquired by the power control value acquisition unit.

3. The heat pump hot water heat source device according to claim 2.

4. an end determination means for determining whether or not a predetermined defrost end condition is satisfied after the defrost operation is started by the defrost start control means; A boiling control means for restarting the boiling operation when the end determination means determines that the defrost end condition is satisfied; and The defrosting termination condition is The defrosting operation is started when the condition switching means switches to either the first defrosting start condition or the second defrosting start condition, which is a common condition. The heat pump hot water heat source machine according to any one of claims 1 to 3.

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