WO2016098141A1 - Heat pump hot water supply device and control method therefor - Google Patents

Abstract

Provided is a heat pump hot water supply device that is combined with a power storage device, and that suppresses power losses and improves power efficiency. In the heat pump hot water supply device 1 according to the present invention, a power storage device 12 is connected, via a switch, to a wiring 32 which connects rectifying means (rectifier 10, power-factor improving reactor 30, smoothing circuit 31) and an inverter 13. A power supply control unit 11, depending on the period of time, disconnects the power storage device 12 from the wiring 32 and controls charge/discharge of the power storage device 12. By charging or discharging the power storage device 12 according to the hot water storing operation or heat retaining operation for each period of time in consideration of operation costs, power losses can be reduced.

Description

Heat pump water heater and control method thereof

The present invention relates to a heat pump hot-water supply device that stores and uses electrical energy in a power storage device, and a control method therefor.

As an air conditioner using a heat pump, a rectifier circuit that converts alternating current of a commercial power source into direct current, a smoothing circuit that smoothes direct current, a frequency control means that converts the smoothed direct current into alternating current of any frequency and supplies electric power to the motor There is known an inverter circuit having a power storage means having a voltage control means for supplying a secondary power source to the smoothing circuit (see, for example, Patent Document 1).

In addition, as a conventional heat pump hot water supply device, a heat pump water heater operated with AC power fed from a commercial power system, and DC power stored and stored in a storage battery by converting AC power fed from the commercial power system into DC power It is equipped with a power storage device that converts power into AC power and supplies power, and stores the AC power of the commercial power system in the power storage device in the midnight hours when the electricity rate is set lower than the daytime, and operates the heat pump water heater in the daytime. In this case, it is known that the operation cost is reduced by supplying electric power from the power storage device (for example, see Patent Document 2 and Patent Document 3).

JP 2001-178177 A Japanese Patent No. 5405963 JP 2013-44466 A

A conventional heat pump water heater configured by combining a power storage device converts AC power of a commercial power system fed to the heat pump water heater into DC power, stores it in the power storage device, and once again stores the stored DC power as AC power. Since power is supplied to the heat pump hot water supply device after conversion, power loss due to repeated conversion between AC and DC has been caused.

In addition, the conventional heat pump water heater operates by appropriately switching between the hot water storage operation and the heat insulation operation based on the hot water amount and the water temperature of the hot water storage tank that changes with fluctuations in the hot water supply, and is not necessarily suitable for the operation of the heat pump water heater. In some situations, power cannot be supplied from the power storage device to the hot water supply device.

The present invention has been made to solve the above problems, and a first object is to suppress power loss and improve power efficiency. The second object is to obtain a method for controlling the power supply from the power storage device in accordance with the operation of the heat pump water heater.

The heat pump water heater according to the present invention is
A heat pump type water heater composed of a compressor, two heat exchangers, a refrigerant circuit for circulating a refrigerant between the compressor and the two heat exchangers, and a water circuit connected to a load side heat exchanger;
An inverter that supplies AC power of an arbitrary frequency to the compressor;
Rectifying means that rectifies AC power supplied from the external power source into DC power and supplies the DC power to the inverter;
A power storage device connected to a wiring connecting the rectifying means and the inverter via a switch, storing DC power output from the rectifying means, and supplying DC power to the inverter;
First control means for controlling the operation of the inverter and the power storage device,
The first control unit controls connection and disconnection of the power storage device to the wiring and charge / discharge of the power storage device according to a time zone.

A heat pump water heater according to the present invention connects a power storage device via a switch in the middle of a wiring connecting a rectifier that converts AC power supplied from an external AC power source into DC power and an inverter that drives a compressor. However, the first control means can control the connection of the power storage device to the wiring and the charge / discharge of the power storage device, and the loss of power can be reduced by reducing the conversion between AC and DC.

It is a block diagram which shows the structure of the heat pump hot-water supply apparatus in Embodiment 1 of this invention. FIG. 3 is a flowchart showing a control method in a chargeable period according to the first embodiment. FIG. 3 is a flowchart showing a control method in a discharge priority period according to the first embodiment. 3 is a diagram illustrating a relationship between a state of a hot water supply device and a storage capacity of a power storage device when operated by the control method according to Embodiment 1. FIG. FIG. 3 is a block diagram showing a configuration of a heat pump hot water supply apparatus having a control circuit for a power storage device configured by a separate circuit in the first embodiment. It is a figure which shows the relationship between the state of the hot water supply apparatus at the time of making it operate | move with the control method in Embodiment 3 of this invention, and the electrical storage capacity of an electrical storage apparatus.

Hereinafter, a heat pump hot water supply apparatus and a control method thereof according to an embodiment of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
In FIG. 1, the structure of the heat pump hot-water supply apparatus concerning this Embodiment is shown. In FIG. 1, a heat pump water heater 1 includes a rectifier 10, a hot water controller 11, a power storage device 12, an inverter 13, a compressor 14, a load side heat exchanger 15, a primary side heat exchanger 16, a power factor improving reactor 30, and a smoothing. The circuit 31 is configured.

The AC power supplied from the external AC power source 2 via the wiring 4 is rectified to DC power by a rectifier 10 formed of a diode, an output waveform is formed by a power factor improving reactor 30, and smoothed by a smoothing circuit 31. After that, it is supplied to the inverter 13 via the wiring 32. Here, the rectifier 10, the power factor improving reactor 30, and the smoothing circuit 31 constitute a rectifying means.

The inverter 13 converts the smoothed DC power into AC power having an arbitrary frequency by using a built-in frequency control means, and supplies it to the compressor 14. The refrigerant compressed by the compressor 14 is supplied to the primary side heat exchanger 16 and the load side heat exchanger 15 via the refrigerant circuit 17. The water supplied through the water supply valve 7 is heated by the load side heat exchanger 15 and stored in the hot water storage tank 3. A circulating water valve 6 is attached to the water circuit 5 connecting the load side heat exchanger 15 and the hot water storage tank 3. The compressor 14, the refrigerant circuit 17 and the water circuit 5 constitute the water heater of the present invention.

The power storage device 12 is connected to a wiring 32 connecting the smoothing circuit 31 and the inverter 13. The power storage device 12 includes a bus voltage detection circuit 21 that detects the voltage across the smoothing circuit 31, a DC switch 25, a storage battery 26, a storage battery voltage detection circuit 22 that detects the voltage across the storage battery 26, and a converter control circuit. 24 and a power storage controller 20 that controls the operation of these circuits. In addition, the power storage control unit 20 is connected to the bus voltage detection circuit 21, the storage battery voltage detection circuit 22, and the converter control circuit 24 through a wiring 27.

Furthermore, the inverter 13 and the power storage control unit 20 are connected to the hot water supply control unit 11 via the wiring 19, and the operation of the inverter 13 and the power storage device 12 is controlled by the hot water supply control unit 11.

In the heat pump hot water supply apparatus 1 according to the above-described embodiment, rectification means (rectifier 10, power factor improving reactor 30, smoothing circuit 31) that converts AC power supplied from the external AC power source 2 into DC power, and a compressor The power storage device 12 is connected to the wiring 32 connecting the inverter 13 that drives the power supply 14 via the DC switch 25, and the hot water supply control unit 11 connects and disconnects the power storage device 12 to the wiring 32 (ON / OFF) and stores the power. The charging / discharging to the apparatus 12 can be controlled.

Next, the basic operation of the heat pump hot water supply apparatus 1 will be described. The AC power fed from the external AC power source 2 is converted into DC power by the rectifier 10, shaped into a waveform by the power factor improving reactor 30, converted to DC power with less pulsating current by the smoothing circuit 31, and supplied to the inverter 13. Is done. The inverter 13 converts the supplied DC power into AC power and drives the compressor 14.

On the other hand, power storage control unit 20 switches on DC switch 25 in response to a control command from hot water supply control unit 11 and outputs a target voltage value command to converter control circuit 24. The converter control circuit 24 drives the switching element 28 of the converter 23 to perform operations of storing energy in the reactor 29 and discharging energy from the reactor 29.

While the storage battery voltage detection circuit 22 detects the voltage of the storage battery 26, the storage control unit 20 controls on / off of the switching element 28 so that the DC bus voltage value matches the target voltage suitable for charging the storage battery 26. To store in the storage battery 26.

Next, the discharging operation from the storage battery 26 of the power storage device 12 will be described. The power storage control unit 20 turns on the DC switch 25 and outputs a target voltage value command to the converter control circuit 24. The converter control circuit 24 detects the bus voltage by the bus voltage detection circuit 21 by driving the switching element 28, and targets the voltage of the storage battery 26 in the energy storage operation in the reactor 29 and the energy release operation from the reactor 29. The on / off state of the switching element 28 is controlled so as to coincide with the DC bus voltage value. At this time, the storage battery 26 is connected to the wiring 32 via the DC switch 25, and DC power is supplied to the inverter 13.

Next, the operation in the hot water supply control unit 11 during the chargeable period will be described with reference to the flowchart of FIG.

Prior to the operation, a time period during which the power storage device 12 may be charged is determined as a chargeable period, and an arbitrary time period is set in advance. As a chargeable period, it is desirable to set a midnight time zone in which the power rate is set lower than the daytime.

First, the hot water supply control unit 11 determines whether or not the current period is a chargeable period (step S201), and if it is a chargeable period (Yes), the process proceeds to step S202, but is not a chargeable period. (No) ends this processing.

Next, it is determined whether or not the heat pump hot-water supply apparatus 1 is not performing a hot water storage operation and a heat retaining operation and is stopped (step S202). If the operation is stopped (Yes), the process proceeds to step S203. When driving (No), the process returns to step S201.

In step S203, which is shifted from step S202, the hot water supply control unit 11 instructs the power storage control unit 20 to start charging, and direct current power is stored in the storage battery 26.

Next, the hot water supply control unit 11 determines whether or not the hot water storage operation or the heat insulation operation should be started (step S204). If the hot water storage operation or the heat insulation operation should be started (Yes), the process proceeds to step S205. When it transfers and does not start hot water storage operation or heat retention operation (No), it transfers to step S207.

In step S205, which is shifted from step S204, the hot water supply control unit 11 instructs the power storage control unit 20 to end charging, and power storage in the storage battery 26 is stopped.

If there is a margin in electric power even if the hot water storage operation or heat insulation operation of the heat pump hot water supply apparatus 1 is performed, it is possible to continue to store electricity in the storage battery 26 with a charge amount commensurate with the margin of electric power.

After the hot water storage operation or the heat retaining operation is started in step S206, which is shifted from step S205, the flow shifts to step S201.

In step S207 to which the process proceeds from step S204, it is determined whether or not the chargeable period ends. When the chargeable period ends (Yes), the process proceeds to step S208 and the chargeable period does not end (No). Proceeds to step S209.

In step S209 which shifts from step S207, it is determined whether or not the storage capacity of the storage battery 26 has reached the full charge state. If the full charge state has been reached (Yes), the flow moves to step S208 and the full charge is performed. If it does not reach (No), the process proceeds to step S204.

In step S208, which shifts from steps S207 and S209, the hot water supply control unit 11 instructs the power storage control unit 20 to end charging, and power storage to the storage battery 26 is stopped.

Next, the operation of the hot water supply control unit 11 in the discharge priority period will be described with reference to the flowchart of FIG.

Prior to the operation, a time zone in which the power storage device 12 wants to discharge is determined as a discharge priority period, and an arbitrary time zone is set in advance. As the discharge priority period, it is desirable to set a daytime period in which a high effect of power leveling can be expected and the power rate is set high.

First, the hot water supply control unit 11 determines whether or not the present is the discharge priority period (step S301), and if it is the discharge priority period (Yes), the process proceeds to step S302, but is not the discharge priority period ( No) ends this process.

Next, it is determined whether or not it is possible to discharge with the amount of power stored in the storage battery 26 (S302). If there is a stored power amount that can be discharged (Yes), the process proceeds to step S303, but the stored power that can be discharged. When there is no electric energy (No), this process is terminated.

Next, it is determined whether the hot water storage operation or the heat insulation operation should be started (step S303). If the hot water storage operation or the heat insulation operation should be started (Yes), the process proceeds to step S304, and the hot water storage operation or the heat insulation operation is started. If not started (No), the process returns to step S301.

In step S304, which is shifted from step S303, the hot water supply control unit 11 instructs the power storage control unit 20 to start discharging, the power storage control unit 20 turns on the DC switch 25, and the converter control circuit 24 causes the switching element 28 of the converter 23 to be turned on. On / off control is performed, and feeding of DC power from the storage battery 26 to the inverter 13 is started. Subsequently, after hot water storage operation or heat insulation operation is started (step S305), the process proceeds to step S306.

Next, it is determined whether the amount of power stored in the storage battery 26 can continue to be discharged (step S306). If there is a stored amount of power that can be discharged (Yes), the process proceeds to step S307, and the stored power amount that can be discharged. If there is no (No), the process proceeds to step S310.

In step S307 to which the process proceeds from step S306, it is determined whether the hot water storage operation or the heat insulation operation during operation is stopped and terminated. When the operation is stopped (Yes), the process proceeds to step S308 and the operation is continued ( No) again proceeds to step S306.

In step S308 which moves from step S307, the hot water storage operation or the heat insulation operation is stopped, and the process moves to step S309.

Next, the hot water supply control unit 11 instructs the power storage control unit 20 to end the discharge, and the power storage control unit 20 switches off the DC switch 25 and stops the supply of DC power from the storage battery 26 via the discharger 23. (Step S309), the process returns to Step S301.

In step S310, which is shifted from step S306, the hot water supply control unit 11 instructs the power storage control unit 20 to end the discharge, and the power storage control unit 20 switches off the DC switch 25 and stops supplying DC power from the storage battery 26. Then, this process ends.

FIG. 4 is a diagram showing the relationship between the operating state of the heat pump hot water supply device 1 when operated by the control method in the present embodiment and the transition 405 of the storage capacity in the operating state of the power storage device 12. The upper stage of FIG. 4 shows the operating state of the hot water supply device, and the lower stage shows the operating state of the power storage device. The horizontal axis represents the time zone of the day.

In FIG. 4, in the hot water storage operation period 401 among the chargeable periods set in the midnight time zone, the operation of charging the storage battery 26 by the power storage device 12 is stopped. On the other hand, in the chargeable period other than the hot water storage operation period 401, the storage battery 26 is charged by the power storage device 12.

On the other hand, the heat retention operation period 402 is a period that does not correspond to either the chargeable period or the discharge priority period. In this period, the power storage device 12 is not charged, and the heat is maintained with the power supplied from the external AC power supply 2. Do the driving.

Moreover, in the heat insulation operation period 403 in the discharge priority period set in the daytime time zone, the power storage device 12 discharges the storage battery 26 and supplies DC power to perform the heat insulation operation.

Then, in the hot water storage operation period 404 due to sudden boiling of the heat pump hot water supply device 1, during the discharge priority period, the storage battery 26 is discharged by the power storage device 12 to supply DC power and the hot water storage operation is performed. In such a case, discharging of the storage battery 26 by the power storage device 12 is stopped, and the hot water storage operation is continued by switching to the power from the external AC power source 2.

As described above, in the present embodiment, the switch 25 is provided in the middle of the wiring 32 that connects the rectifier that converts AC power supplied from the external AC power source 2 to DC power and the inverter 13 that drives the compressor 14. The hot water control unit 11 can control the connection of the power storage device 12 to the wiring 32 and the charge / discharge of the power storage device 12.

As a result, by charging and discharging the power storage device 12 in accordance with hot water storage operation and heat insulation operation for each time zone in consideration of operation costs, it is possible to reduce power loss and reduce operation costs. Moreover, it can contribute to power leveling.

In this Embodiment, the structure of the heat pump hot-water supply apparatus 1 is not limited to the structure shown in FIG. FIG. 5 shows that the converter 23 of the power storage device 12 is realized by another circuit, and includes a charging switching element 40, a step-up chopper switching element 41, and a discharging switching element 42.

When charging the storage battery 26, the converter control circuit 24 switches the charging switching element 40 on. On the other hand, when the charging is stopped, the converter control circuit 24 switches the charging switching element 40 off.

Moreover, when discharging from the storage battery 26, the converter control circuit 24 switches the discharge switching element 42 on. When the discharge is stopped, the converter control circuit 24 switches the discharge switching element 42 to OFF.

Needless to say, by connecting a direct current power generation system such as solar power generation or a fuel cell to the power storage device 12, it is possible to operate a heat pump water heater with a further reduced utilization rate of commercial power.

Embodiment 2. FIG.
In the present embodiment, the power storage capacity of the power storage device 12 of the heat pump hot water supply device 1 is increased, and the hot water storage operation and the heat insulation operation are made longer by feeding DC power from the storage battery 26 of the power storage device 12 during the daytime. I can do it.

Specifically, the wiring for charging and discharging the storage battery 26 of the power storage device 12 disposed between the rectifier 10 and the inverter 13 of the heat pump water heater 1 shown in FIG. 1 and the signal wiring from the power storage control unit 20 are externally connected. A terminal block is provided so that it can be pulled out, and each wiring is connected to the terminal of the terminal block. Then, the charge / discharge wiring of the storage battery prepared outside and the signal wiring 27 are connected to the terminal of the terminal block.

As described above, in the present embodiment, a storage battery prepared outside the heat pump hot water supply apparatus 1 is connected and controllable, so the power storage capacity of the power storage apparatus 12 is increased, and the power storage apparatus is operated during the daytime. Thus, the operation period can be extended by supplying electric power by discharging from 12, and as a result, even when a larger hot water storage tank is provided, the operation cost can be reduced.

Embodiment 3 FIG.
In this embodiment, whenever hot water stored in the hot water storage tank 3 is used and reduced by the hot water supply control unit 11 of the heat pump hot water supply device 1 during the discharge priority period, DC power is supplied by discharging from the storage battery 26 of the power storage device 12. Control hot water storage operation to make hot water.

Specifically, the control in the discharge priority period in the power supply control unit 11 is given priority to hot water storage operation by supplying DC power by discharge from the storage battery 26 of the power storage device 12 every time the amount of hot water stored in the hot water storage tank 3 decreases. In the heat insulation operation, the operation is changed to control in which the operation is performed with the electric power supplied from the external AC power supply 2 and the electric power from the power storage device 12 is not supplied.

FIG. 6 shows the relationship between the operating state of heat pump water heater 1 in the operation of the present embodiment and the transition of the storage capacity in the operating state of power storage device 12.

In FIG. 6, in the hot water storage operation period 601 within the chargeable period set in the midnight time zone, the operation of charging the storage battery 26 by the power storage device 12 is stopped. In the chargeable period other than the hot water storage operation period 601, the storage battery 26 is charged by the power storage device 12.

On the other hand, the heat insulation operation period 602 is a case in which neither the chargeable period nor the discharge priority period is applicable, and the power storage device 12 is not charged, and the heat insulation operation is performed with the electric power supplied from the external AC power supply 2. Do.

Further, in the heat insulation operation period 603 in the discharge priority period set in the daytime time zone, the heat insulation operation is performed with the electric power supplied from the external AC power supply 2 without performing the power supply due to the discharge from the power storage device 12.

In the hot water storage operation period 604 due to the increase in boiling of the heat pump water heater 1 during the discharge priority period due to the decrease in the amount of hot water in the hot water storage tank 3 due to the use of hot water, the storage battery 26 is discharged by the power storage device 12 to supply DC power. Perform hot water storage operation.

Furthermore, in the hot water storage operation period 605 due to increased boiling, during the discharge priority period, the storage battery 26 is discharged by the power storage device 12 and DC power is supplied to perform the hot water storage operation. The discharging of the storage battery 26 is stopped, the electric power supplied from the external AC power supply 2 is switched to continue the hot water storage operation.

As described above, since the hot water supply control unit 11 of the heat pump hot water supply device 1 preferentially performs the hot water storage operation by the power supply from the power storage device 12 during the discharge priority period, the amount of stored hot water can be stored by the amount of power stored in the power storage device 12. Since hot water can be replenished to the hot water storage tank, the capacity of the hot water storage tank 3 can be reduced.

Moreover, it can contribute to restraining peak electric power by using the electric power charged in the time zone of midnight by the electrical storage apparatus 12 with respect to the hot water storage operation which consumes electric power more compared with the heat insulation operation.

DESCRIPTION OF SYMBOLS 1 Heat pump hot water supply apparatus 2 External AC power supply 3 Hot water storage tank 4, 18, 32, 33, 34 Wiring 5 Water circuit 6 Circulating water valve 7 Water supply valve 10 Rectifier 11 Hot water supply control part 12 Power storage device 13 Inverter 14 Compressor 15 Load side heat exchange Unit 16 Primary side heat exchanger 17 Refrigerant circuit 19, 27 Signal wiring 20 Storage control unit 21 Bus voltage detection circuit 22 Storage battery voltage detection circuit 23 Converter 24 Converter control circuit 25 DC switch 26 Storage battery 30 Power factor improving reactor 31 Smoothing circuit

Claims (6)

1. A heat pump type water heater composed of a compressor, two heat exchangers, a refrigerant circuit for circulating a refrigerant between the compressor and the two heat exchangers, and a water circuit connected to a load side heat exchanger;
   An inverter that supplies AC power of an arbitrary frequency to the compressor;
   Rectifying means that rectifies AC power supplied from the external power source into DC power and supplies the DC power to the inverter;
   A power storage device connected to a wiring connecting the rectifying means and the inverter via a switch, storing DC power output from the rectifying means, and supplying DC power to the inverter;
   First control means for controlling the operation of the inverter and the power storage device,
   The first control means controls connection / disconnection of the power storage device to / from the wiring and charge / discharge of the power storage device according to a time zone.
2. The power storage device includes: a first storage battery; and a second control unit that controls charging / discharging of the first storage battery and disconnection of the switch according to an instruction of the first control unit. The heat pump hot water supply apparatus described in 1.
3. The heat pump hot-water supply apparatus according to claim 1 or 2, wherein the power storage device includes a connection terminal to which an external second storage battery can be connected.
4. It is a control method of the heat pump hot-water supply apparatus in any one of Claim 1 thru | or 3, Comprising: The 1st time slot | zone which may be charged with the said electrical storage apparatus beforehand is set, In the said 1st time slot | zone, A method of controlling a heat pump hot water supply apparatus, wherein the power storage device is charged in a period excluding a period of hot water storage operation and heat insulation operation.
5. It is a control method of the heat pump hot-water supply apparatus in any one of Claims 1 thru | or 3, Comprising:
   A second time zone in which power discharged from the power storage device is preferentially supplied to the inverter is set in advance, and the power storage device is discharged during the hot water storage operation and the heat insulation operation in the second time zone. A method for controlling a heat pump water heater, wherein power is supplied to the inverter.
6. 6. The method of controlling a heat pump hot water supply apparatus according to claim 5, wherein hot water storage operation is preferentially performed by power supply from the power storage device each time the amount of hot water stored in a hot water storage tank for storing hot water supplied from the water heater decreases. A method of controlling a heat pump hot water supply device that covers hot water.

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