JP2008128616A - Hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply system capable of safely continuing operation by preventing a shutdown of an apparatus or unstable operation due to an overcurrent even when there is an overload. <P>SOLUTION: The hot water supply system is provided with a hot water storage tank storing hot water heated by a heat pump. The heat pump is provided with a compressor, a water heat exchanger, an expansion valve, an air heat exchanger, and a discharge temperature sensor detecting a temperature of a coolant discharged from the compressor. When a current value detected by a current sensor detecting a current supplied to the heat pump exceeds a predetermined current upper limit, a frequency of a driving power source supplied to the compressor is lowered, and the current value detected by the current sensor becomes less than a predetermined restoration current value less than the current upper limit, control is carried out such that the frequency of the driving power source is raised, an opening of the expansion value is increased, and a target discharge temperature of the coolant discharged from the compressor is lowered. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hot water supply apparatus, and more particularly to a heat pump hot water supply apparatus using a refrigerant.

  Recently, the use of hot water supply devices using heat pumps is expanding from the viewpoint of energy saving. As shown in FIG. 7, this type of hot water supply apparatus generally includes a bathtub 1, a heat pump 2 for heating water supplied from the outside, a hot water storage tank 3 for holding hot water heated by the heat pump 2, and the hot water storage. A hot water supply pipe 4 that guides hot water stored in the tank 3 to the bathtub 1 is provided.

  The heat pump 2 has a compressor 6 that compresses a predetermined refrigerant by controlling the compression force according to the frequency of the drive power supplied in detail, as shown in FIG. 8, and a first pipe line downstream of the compressor 6. 7a, a water heat exchanger 8 that exchanges heat and gives energy held by the refrigerant to the water held in the hot water storage tank 3, and a second pipe line 7b in the subsequent stage of the water heat exchanger 8. And an expansion valve 9 for expanding the refrigerant heat-exchanged by the water heat exchanger 8, and connected to a subsequent stage of the expansion valve 9 via a third pipe line 7c to exchange heat and become a refrigerant. An air heat exchanger 10 that gives energy held by air, a fourth pipe 7d that guides the refrigerant heat-exchanged by the air heat exchanger 10 to the compressor 6, and a temperature of the refrigerant discharged from the compressor 6 are detected. Discharge temperature sensor 11 and the discharge temperature Capacitors 11 is provided with a heat pump control unit 12 which compares the temperature with a predetermined target discharge temperature of the refrigerant detected, controls the operation of the compressor so as to reduce the deviation.

  Note that an accumulator that protects the compressor 6 from liquid compression when the refrigerant is not completely evaporated by the air heat exchanger 10 is provided in the fourth pipeline 7d that connects the air heat exchanger 10 and the compressor 6. 13 and the internal heat exchanger 14 for exchanging heat and cooling the refrigerant flowing in the second piping path 7b with the refrigerant (low-temperature refrigerant) flowing in the fourth piping path 7d is the second piping path 7b and the fourth piping. It is interposed in the road 7d.

  The heat pump control unit 12 has a current sensor (not shown in FIG. 8) that detects the current value of the drive power source supplied to the heat pump 2. The heat pump control unit 12 monitors the current value detected by the current sensor and controls the compressor 6 not to be overloaded. Incidentally, a heat pump controller that performs this type of heat pump control is known (see, for example, Patent Document 1).

Heat pump control represented by this type of heat pump controller performs control based on the current value detected by the current sensor when the compressor is overloaded. In other words, this type of heat pump control shifts to a so-called regulated operation mode in which the frequency of the drive power supplied to the compressor is reduced when the current supplied to the compressor exceeds a predetermined current upper limit value. Next, when it is detected that the heat pump control unit has fallen below a predetermined regulated current value that is equal to or lower than the current upper limit value, the heat pump control unit increases the frequency of the drive power supply to shift to the normal operation mode.
Japanese Patent Publication No. 5-54022

  However, the heat pump control described above has a problem that the control may become unstable soon after the transition from the regulated operation mode to the normal operation mode, and the control may become unstable again. In particular, as described above, the heat pump control only for controlling the compressor cannot cope with the phenomenon that the current supplied to the heat pump increases, and there is a problem that stable operation becomes difficult.

  The present invention has been made in consideration of such a conventional situation, and the object of the present invention is to prevent a hot water supply device from being stopped or unstable due to overcurrent even in an overload, and to be safe. An object of the present invention is to provide a hot water supply device capable of continuing operation.

In order to achieve the above-mentioned object, the hot water supply apparatus of the present invention is a hot water supply apparatus including a hot water storage tank for storing hot water heated by a heat pump,
The heat pump is connected to a compressor whose compression force is controlled by a frequency of a supplied driving power source and compresses a predetermined refrigerant, and connected to a subsequent stage of the compressor via a first pipe line, and the hot water storage tank. A water heat exchanger for exchanging the energy held by the refrigerant to the water held by the heat exchanger, and connected to the subsequent stage of the water heat exchanger via a second pipe line, and the water heat exchanger An expansion valve whose degree of opening for expanding the heat-exchanged refrigerant is variable, and an expansion valve connected to the subsequent stage of the expansion valve via a third pipe line, and the energy held by the air is given to the refrigerant through heat exchange An air heat exchanger, a fourth piping for guiding the refrigerant heat-exchanged by the air heat exchanger to the compressor, a discharge temperature sensor for detecting the temperature of the refrigerant discharged from the compressor, The cooling temperature detected by the discharge temperature sensor Temperature and compared with a predetermined target discharge temperature, comprising a heat pump control unit for the deviation to control the compressive force of the compressor so as to be 0,
The heat pump control unit further includes a current sensor that detects a current value of the driving power source supplied to the heat pump, and supplies the compressor when the current value detected by the current sensor exceeds a predetermined current upper limit value. When the current value detected by the current sensor falls below a predetermined return current value equal to or lower than the current upper limit value after lowering the frequency of the driving power source, the frequency of the driving power source is increased and the expansion valve A regulation operation mode is provided which increases the opening degree and further lowers the target discharge temperature of the refrigerant discharged from the compressor.

Preferably, the heat pump control unit supplies power to the compressor when a frequency of a power supply voltage for driving the compressor exceeds a predetermined minimum frequency and a current value detected by the current sensor exceeds a predetermined current value. It is desirable to cut off.
The heat pump control unit lowers the frequency of the drive power supply when a current value exceeding a predetermined current upper limit value is continuously detected for a predetermined time for each frequency of the power supply voltage applied to the compressor. Composed.

Preferably, the heat pump control unit increases the frequency of the drive power supply when a current value equal to or lower than a predetermined return current value is detected for a predetermined time for each frequency of the power supply voltage applied to the compressor. Is desirable.
Further, the heat pump control unit cancels the restricted operation mode when the frequency of the drive power source returns to the frequency before the restricted operation mode.

Preferably, the heat pump control unit cancels the restricted operation mode when the frequency of the drive power source returns to the target operation frequency when the compressor is started up and shifts to the restricted operation mode.
More preferably, when the heat pump control unit shifts to the restricted operation mode during the defrost operation, it is desirable that the restricted operation mode is canceled when the frequency of the drive power source returns to the target operation frequency.

The heat pump control unit is configured to continuously operate at a frequency of the drive power source for a predetermined time when the restricted operation mode is canceled.
The above-described hot water supply device prevents the device from being stopped or unstable due to an overcurrent during an overload, and continues to operate safely.

  According to the hot water supply device of the present invention, when the current value detected by the current sensor that detects the current value of the drive power source supplied to the heat pump exceeds the predetermined current upper limit value, the drive power source supplied to the compressor included in the heat pump When the current value detected by the current sensor falls below a predetermined return current value, the frequency of the drive power supply is increased, the opening of the expansion valve is increased, and the compressor is discharged from the compressor. Since the regulated operation mode for lowering the target refrigerant discharge temperature is provided, stable operation can be continued even if the heat pump is overloaded.

  Further, according to the hot water supply apparatus of the present invention, when the frequency of the power supply voltage for driving the compressor is the predetermined minimum frequency and the current value detected by the current sensor exceeds the predetermined current value, the power supply to the compressor is performed. Since it is refused, high safety can be obtained, and when the regulated operation mode is released, it is configured to operate continuously for a predetermined time at the frequency of the drive power supply, so it will return and regulate again Practical effects such as prevention of a phenomenon such as entering and stable control can be obtained.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIGS. 1-6 is an example of Embodiment which implements invention, Comprising: In the hot water supply apparatus which takes the structure similar to the conventional hot water supply apparatus and heat pump shown in FIG.7 and FIG.8, the flowchart which shows the action | operation of the heat pump control part 12 is shown. It is. Therefore, since these basic structures are the same as those of the conventional one shown in FIGS. 7 and 8, the description thereof is omitted.

  Incidentally, the compressor 6 is driven by, for example, an induction motor, and is driven by an inverter 20 that is controlled by varying the frequency of a driving power source that gives the rotational speed as shown in FIG. The input of the inverter 20 is supplied with DC power from a converter 22 that once converts AC of commercial frequency supplied from the commercial power supply 21 into DC. Further, a current sensor 23 for detecting a current supplied from a commercial power source is interposed on the primary side of the converter 22 and is given to the heat pump control unit 12.

As will be described in detail later, the heat pump control unit 12 includes control processes for starting up the compressor 6, normal control, and defrost control, as shown in the process control flowchart of FIG.
First, when the power is turned on, the heat pump control unit 12 shifts to a standby process waiting for an operation command input from an operation unit (not shown) (step S1). In the standby process, when the heat pump control unit 12 receives the boiling operation command (step S2), the heat pump control unit 12 proceeds to the operation process (step S3). The heat pump control unit 12 that has shifted to the operation process calculates the required hot water discharge capacity and the like from the outside air temperature detected by an outside air temperature sensor (not shown), the temperature of the feed water introduced to the heat pump 2, and the like, and determines the operation condition (step S4). ).

  The heat pump control unit 12 that has determined the operation condition executes the start-up control of the heat pump (step S5). In this start-up control, the frequency of the drive power supplied to the compressor 6 is increased stepwise at a predetermined time interval T, and at the same time, the opening of the expansion valve 9 is opened stepwise to meet the operating condition obtained in step S4. Let Then, the heat pump control unit 12 continues the rising control until the operating condition obtained in step S4 is reached, and when it is determined that the heat pump 2 has completed rising (step S6), the heat pump control unit 12 shifts to normal control (step S7).

When the heat pump control unit 12 that has shifted to the normal control determines that the temperature of the water returning to the heat pump 2 has become higher than the boiling completion temperature specified in advance, the boiling pump process ends (step S9), and step S1 again. The standby process is started.
In the case of performing the defrosting during the normal control in step S7, after the process shifts to the defrosting process (step S10), the control after step S5 is executed again.

  Schematically, the characteristic control of the hot water supply apparatus of the present invention that operates as described above will be described in more detail. Incidentally, the frequency of the drive power supply given to the compressor 6 by the heat pump control unit 12 can be changed for each of a plurality of frequency steps obtained by adding a predetermined frequency step Δf from the lowest frequency f, and the frequency gradually increases from the lowest frequency f. It is assumed that the output frequency of the inverter 20 is increased until a predetermined driving capability is obtained. As will be described in detail later, when an overcurrent flows to the compressor 6 due to an overload or the like, an upper limit value (current upper limit value) of the current supplied to the compressor 6 for each frequency, the drive capacity is lowered by once reducing the frequency. As shown in FIG. 3, it is assumed that a reference return current value that can raise the frequency again to increase the driving capability after the overcurrent state is avoided by reducing the current value is predetermined for each frequency.

In this figure, the current value for each frequency is I _r <I ₀ <I ₁ <I ₂ <... <I ₅ <I _6. For example, the current upper limit value at a certain operation frequency and the operation frequency The return current value having a frequency higher by the frequency step Δf is set to the same value.
Next, in the rise control in step S5 described above, the heat pump control unit 12 executes each process shown in FIG. First, the heat pump control unit 12 determines whether or not the current value detected by the current sensor 23 exceeds the current upper limit value at the frequency of the drive power supply provided to the compressor 6 (step S20). When the heat pump control unit 12 determines in step S20 that the current upper limit value in the frequency of the drive power source has been exceeded, whether or not the state continues for a predetermined time ta (for example, ta is about 5 seconds). It is determined whether or not (step S21).

When it is determined in step S21 that the time exceeding the current upper limit value is not continued for the predetermined time ta, the heat pump control unit 12 returns to step S20 again and continues the current detection.
In step S21, when the heat pump control unit 12 determines that the state in which the current upper limit value is exceeded continues for the predetermined time ta, whether or not the frequency of the drive power supply is the lowest frequency given to the compressor 6 further. Is determined (step S22). In step S22, when the heat pump control unit 12 determines that the frequency of the drive power supplied to the compressor 6 is not the lowest frequency, the heat pump control unit 12 decreases the frequency of the drive power supplied to the compressor 6 by one level. For example, if the frequency of the drive power supply is f + 4Δf, it is given to the compressor 6 as f + 3Δf, which is a frequency one step lower (by Δf) (step S22). And the heat pump control part 12 cancels | releases the stand-up control mentioned above (step S24), and transfers to a regulation operation mode (step S25).

  At this time, the heat pump control unit 12 determines whether or not the current value detected by the current sensor 23 is equal to or less than the return current value at a frequency one step lower than the current frequency at which the compressor 6 is driven. The determination is made with reference to (step S26). Next, the heat pump control unit 12 determines whether or not the current value equal to or lower than the return current value determined in step S26 continues for a predetermined time tb (for example, about 20 seconds) (step S27), When it is determined that the operation is continued for a while, it is further determined whether or not the frequency of the drive power supplied to the compressor 6 is the target operation frequency (step S28). In step S28, when the heat pump control unit 12 determines that the frequency of the drive power source is the target operation frequency, the heat pump control unit 12 cancels the restricted operation mode and shifts to normal operation (step S29).

  When the heat pump control unit 12 determines in step S27 that the time exceeding the current upper limit value has not continued for the predetermined time tb, the heat pump control unit 12 returns to step S26 again and continues the current detection. . Moreover, when it determines with the heat pump control part 12 not having reached | attained the target operation frequency by step S28, it performs the regulation operation mode after step S25 again.

  When the heat pump control unit 12 determines in step S22 that the frequency of the drive power supply is the lowest frequency, the heat pump control unit 12 stops driving the compressor 6 assuming that some abnormality (error) has occurred (step S22). In step S26, when the heat pump control unit 12 determines that the current value detected by the current sensor 23 is not less than the return current value at a frequency one step lower than the frequency of the drive power supply currently applied to the compressor 6, further driving is performed. It is determined whether or not the upper limit current value at a frequency one step below the frequency of the power supply has been exceeded (step S31).

  When it is determined in step S31 that the heat pump control unit 12 does not exceed the upper limit current value at a frequency that is one step lower than the frequency of the drive power supply, the heat pump control unit 12 executes the processing after step S25 again, while the upper limit current value is exceeded. When it is determined, it is determined whether or not this state continues for a predetermined time ta (step S32). When it is determined in step S32 that the predetermined time ta has not been exceeded, the heat pump control unit 12 executes the processing from step S25 onward again, and when it is determined that the predetermined time ta has been exceeded, the process returns to step S22. The subsequent processing is executed.

That is, when the current value detected by the current sensor 23 does not fall below the return current value and exceeds the current upper limit value at the frequency of the driving power source, the heat pump control unit 12 has the lowest driving power frequency applied to the compressor 6. If it is not a frequency, the frequency is lowered by one step, and the current upper limit value and the return current value determined in advance at that frequency are used as criteria.
Next, normal control of the heat pump control unit 12 in the hot water supply apparatus of the present invention will be described with reference to the flowchart shown in FIG. First, the heat pump control unit 12 determines whether or not the current value detected by the current sensor 23 exceeds the current upper limit value at the frequency of the drive power supply provided to the compressor 6 (step S40). When the heat pump control unit 12 determines in step S40 that the current upper limit value in the frequency of the drive power source has been exceeded, the state continues for a predetermined time ta (for example, ta is about 5 seconds). It is determined whether or not there is (step S41). When it is determined in step S41 that the time exceeding the current upper limit value is not continued for the predetermined time ta, the heat pump control unit 12 returns to step S40 again and continues the current detection.

  Next, when the heat pump control unit 12 determines in step S41 that the state where the current upper limit value is exceeded continues for a predetermined time ta, whether the frequency of the drive power supply is the lowest frequency given to the compressor 6 or not. It is determined whether or not (step S42). When the heat pump control unit 12 determines in step S42 that the frequency of the drive power supplied to the compressor 6 is not the lowest frequency, the heat pump control unit 12 decreases the frequency of the drive power supplied to the compressor 6 by one level (step S43).

  Then, the heat pump control unit 12 shifts to the regulated operation mode (step S44). At this time, the heat pump control unit 12 determines whether or not the current value detected by the current sensor 23 is equal to or less than the return current value at a frequency one step lower than the current frequency at which the compressor 6 is driven. The determination is made with reference to (step S45). Next, the heat pump control unit 12 determines whether or not the current value equal to or lower than the return current value determined in step S45 is continued for a predetermined time tb (for example, 20 seconds) (step S46), and for a predetermined time tb. When it is determined that the operation is continued, the frequency of the drive power supplied to the compressor 6 is lowered by one step, the opening degree of the expansion valve 9 is increased at the same time, and the temperature target value of the refrigerant discharged from the compressor 6 ( The target discharge temperature is decreased (step S47). That is, the heat pump controller 12 reduces the current flowing through the compressor 6 by reducing the load applied to the compressor 6 in step S47. And the heat pump control part 12 returns to step S44 again, and performs subsequent processing continuously.

  When the heat pump control unit 12 determines in step S42 that the frequency of the drive power supply is the lowest frequency, the heat pump control unit 12 stops driving the compressor 6 assuming that some abnormality (error) has occurred (step S48). In step S45, when the heat pump control unit 12 determines that the current value detected by the current sensor 23 is not less than or equal to the return current value at a frequency one step lower than the current frequency applied to the compressor 6, the current frequency is further decreased. Then, it is determined whether or not the upper limit current value at a frequency one level lower than the upper limit is exceeded (step S49).

  In step S49, when the heat pump control unit 12 determines that the upper limit current value is not exceeded at a frequency one step lower than the current frequency, the heat pump control unit 12 performs the processing after step S44 again, and determines that the upper limit current value has been exceeded. If so, it is determined whether or not this state continues for a predetermined time ta (step S50). When it is determined in step S50 that the predetermined time ta has not been exceeded, the heat pump control unit 12 executes the processing after step S44 again, and when it is determined that the predetermined time ta has been exceeded, the process returns to step S42 and thereafter. Execute the process.

  Next, defrost control executed by the heat pump control unit 12 in the hot water supply apparatus of the present invention will be described with reference to the flowchart shown in FIG. First, the heat pump control unit 12 determines whether or not the current value detected by the current sensor 23 exceeds the current upper limit value at the current frequency (step S60). When the heat pump control unit 12 determines in step S60 that the current upper limit value at the current frequency is exceeded, the state does not continue for a predetermined time ta (for example, ta is a time of about 5 seconds). Whether or not (step S61).

  When it is determined in step S61 that the time exceeding the current upper limit value has not continued for the predetermined time ta, the heat pump control unit 12 returns to step S60 again and continues the current detection. In step S61, when the heat pump control unit 12 determines that the state in which the current upper limit value is exceeded continues for the predetermined time ta, whether the frequency of the drive power supply is the lowest frequency given to the compressor 6 or not. It is determined whether or not (step S62).

In step S62, when the heat pump control unit 12 determines that the frequency of the drive power supplied to the compressor 6 is not the lowest frequency, the heat pump control unit 12 supplies the drive power supplied to the compressor 6 by reducing the frequency by one step (step S63). ).
Then, the heat pump control unit 12 shifts to the regulated operation mode (step S64). At this time, the heat pump control unit 12 determines whether or not defrost control is being performed (step S65). Then, the heat pump control unit 12 that has determined that the defrost control is being performed determines whether the current value detected by the current sensor 23 is equal to or less than the return current value at a frequency one step lower than the current frequency at which the compressor 6 is driven. Is determined (step S66). Next, the heat pump control unit 12 determines whether or not the current value equal to or lower than the return current value determined in step S66 continues for a predetermined time tb (for example, 20 seconds) (step S67), and for a predetermined time tb. When it is determined that it is not continued, the process returns to step S66 and the determination of the current value is continued. On the other hand, when it is determined that the current value continues for a predetermined time tb, the process returns to step S60 and the control is continued.

  When the heat pump control unit 12 determines that the frequency of the drive power supply is the lowest frequency in step S62, the heat pump control unit 12 stops driving the compressor 6 because there is some abnormality (error) (step S68). In step S66, when the heat pump control unit 12 determines that the current value detected by the current sensor 23 is not less than or equal to the return current value at a frequency one step lower than the current frequency, the heat pump control unit 12 further has a frequency one step lower than the frequency of the drive power supply. It is determined whether or not the upper limit current value is exceeded (step S70).

  When the heat pump control unit 12 determines in step S70 that the upper limit current value at a frequency one step below the current frequency is not exceeded, the process after step S64 is executed again, while the upper limit current value is determined to be exceeded. If so, it is determined whether or not this state continues for a predetermined time ta (step S71). When it is determined in step S71 that the predetermined time ta has not been exceeded, the heat pump control unit 12 executes the processing after step S64 again, and when it is determined that the predetermined time ta has been exceeded, the process returns to step S62 and thereafter. Execute the process.

  Thus, according to the hot water supply apparatus of the present invention, when the state in which the current value detected by the current sensor 23 for detecting the current value of the drive power source supplied to the heat pump exceeds the predetermined current upper limit value continues for a predetermined time, the heat pump is provided. When the frequency of the drive power source supplied to the compressor 6 is lowered and then the state in which the current value detected by the current sensor falls below the predetermined return current value continues for a predetermined time, the frequency of the drive power source is increased and the expansion valve 9 is provided, and a regulated operation mode for lowering the target discharge temperature of the refrigerant discharged from the compressor 6 is provided, so that stable operation can be continued even if the heat pump is overloaded.

  Further, according to the hot water supply apparatus of the present invention, when the frequency of the driving voltage for driving the compressor 6 is the predetermined minimum frequency and the current value detected by the current sensor 23 exceeds the predetermined current value, the power source for the compressor 6 is supplied. In addition to being able to obtain a high level of safety, the frequency of the drive power supply is changed to the frequency before the regulated operation mode after the transition to the regulated operation mode during startup (startup), normal operation, and defrost operation. When it returns, it is configured to cancel the regulated operation mode and continue to operate at that frequency for a predetermined time, thus preventing the hunting phenomenon that immediately returns to the regulated operation mode after the regulated operation mode is released In addition, there are significant practical effects such as being able to obtain stable control.

  The hot water supply apparatus of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

The hot water supply apparatus which concerns on one Embodiment of this invention WHEREIN: The block diagram which shows schematic structure of the power supply part which drives a compressor. The flowchart which shows the operation | movement procedure of the hot water supply apparatus which concerns on one Embodiment of this invention. The figure which shows the upper limit electric current value and return electric current value which were predetermined for every frequency of the drive power supply. The flowchart which shows the operation | movement procedure of the starting control shown in FIG. The flowchart which shows the operation | movement procedure of the normal control shown in FIG. The flowchart which shows the operation | movement procedure of the defrost control shown in FIG. The schematic block diagram which shows schematic structure of the hot water supply apparatus using a heat pump. The schematic block diagram which shows the principal part structure of a heat pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Hot water storage tank 6 Compressor 7a, 7b, 7c, 7d Pipe line 8 Water heat exchanger 9 Expansion valve 10 Air heat exchanger 11 Discharge temperature sensor 12 Heat pump control part 14 Internal heat exchanger 23 Current sensor

Claims (8)

A hot water supply apparatus having a hot water storage tank for storing hot water heated by a heat pump,
The heat pump is a compressor that compresses a predetermined refrigerant by controlling the compression force according to the frequency of the drive power supplied.
A water heat exchanger connected to the subsequent stage of the compressor via a first pipe line, and exchanging heat to give the energy held by the refrigerant to the water held in the hot water storage tank;
An expansion valve that is connected to the subsequent stage of the water heat exchanger via a second pipe line, and the opening degree of which can expand the refrigerant heat-expanded by the water heat exchanger,
An air heat exchanger connected to the latter stage of the expansion valve via a third pipe line, and giving the refrigerant the energy held by the air by heat exchange;
A fourth pipe that guides the refrigerant heat-exchanged by the air heat exchanger to the compressor;
A discharge temperature sensor for detecting a temperature of the refrigerant discharged from the compressor;
A heat pump control unit that compares the temperature of the refrigerant detected by the discharge temperature sensor with a predetermined target discharge temperature and controls the compression force of the compressor so that the deviation becomes zero;
The heat pump control unit further includes a current sensor that detects a current value of the drive power source supplied to the heat pump,
When the current value detected by the current sensor exceeds a predetermined current upper limit value, the frequency of the drive power supply supplied to the compressor is lowered, and then the current value detected by the current sensor is equal to or lower than the current upper limit value. A regulation operation mode for increasing the frequency of the drive power supply, increasing the opening of the expansion valve, and lowering the target discharge temperature of the refrigerant discharged from the compressor Hot water supply device characterized by   The heat pump controller cuts off the power supply to the compressor when the frequency of the power supply voltage for driving the compressor exceeds a predetermined minimum frequency and the current value detected by the current sensor exceeds a predetermined current value. The hot water supply apparatus according to claim 1, which is a thing.   The heat pump control unit lowers the frequency of the drive power supply when a current value exceeding a predetermined current upper limit value for each frequency of the power supply voltage applied to the compressor is continuously detected for a predetermined time. The hot-water supply apparatus of Claim 1 or 2.   The heat pump control unit increases the frequency of the drive power supply when a current value equal to or lower than a predetermined return current value is continuously detected for a predetermined time for each frequency of the power supply voltage applied to the compressor. The hot-water supply apparatus in any one of Claims 1-3.   The hot water supply device according to any one of claims 1 to 4, wherein the heat pump control unit is configured to cancel the regulated operation mode when the frequency of the drive power source returns to a frequency before the regulated operation mode.   The said heat pump control part cancels | releases this restriction | limiting operation mode, if the frequency of the said drive power supply returns to a target operation frequency, when it transfers to the said restriction | limiting operation mode at the time of starting of the said compressor. The hot water supply device according to crab.   The said heat pump control part cancels | releases this regulation operation mode, if the frequency of the said drive power supply returns to a target operation frequency when it transfers to the said regulation operation mode during defrost operation. The hot water supply device described.   The hot water supply device according to any one of claims 1 to 7, wherein the heat pump control unit continuously operates for a predetermined time at a frequency of a driving power source when the restricted operation mode is canceled.

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