JPWO2020225905A1 - Hot water storage type hot water supply system - Google Patents

Abstract

The hot water storage type hot water supply system of the present invention is supplied with power from a grid power facility (36) and a power generation device (30) connected to the grid power facility (36) to generate power using renewable energy. Will be installed in. The hot water storage type hot water supply system includes a hot water storage tank (10), a heating means (101) that consumes electric power to heat water, and a control device (17) that controls a boiling operation for heating water in the hot water storage tank by the heating means. And. The control device (17) sets the target hot water temperature in the boiling operation to at least two, the maximum hot water temperature which is the highest temperature among the target hot water temperatures that can be set, and the low hot water temperature which is lower than the maximum hot water temperature. It can be changed to temperature. The control device (17) uses the surplus power with the maximum hot water temperature as the target hot water temperature when the power sale of the surplus power obtained by excluding the power used from the power generated by the power generation device (30) is being suppressed. Perform boiling operation.

Description

The present invention relates to a hot water storage type hot water supply system.

The hot water storage type hot water supply system has a hot water storage tank, and can perform a boiling operation in which hot water in the hot water storage tank is boiled to store heat. In this boiling operation, there is known a hot water storage type hot water supply system that performs boiling operation by utilizing the surplus power when there is surplus power generated by power generation equipment such as solar power generation minus the power used. There is.

For example, in Japanese Patent Application Laid-Open No. 2017-036842, regarding the control of boiling operation, when surplus electric power exists, the surplus electric power is used to perform boiling operation at a relatively low low temperature target temperature for boiling. It is described that after the operation is completed, the boiling operation is performed at a high temperature target temperature when surplus electric power is present.

Japanese Patent Application Laid-Open No. 2017-036842

As a result of boiling operation utilizing surplus electric power, the amount of electric power to be sold is reduced. Therefore, if the feasibility of the boiling operation is determined only by the presence or absence of surplus electric power, the amount of electricity sold by the user may decrease, resulting in a decrease in the cost merit of the user. Further, a stepwise boiling operation in which boiling is performed at a low temperature and then again at a high temperature as described in Japanese Patent Application Laid-Open No. 2017-036842 is not preferable because the operating efficiency is low.

The present invention has been made to solve the above-mentioned problems, and provides an improved hot water storage type hot water supply system that efficiently utilizes surplus electric power to perform boiling operation and improve the cost merit of the user. The purpose is to do.

The hot water storage type hot water supply system of the present invention is installed so as to be supplied with power from a grid power facility and a power generation device connected to the grid power facility and generating power by using renewable energy. The hot water storage type hot water supply system includes a hot water storage tank, a heating means for heating water by consuming electric power, and a control device for controlling a boiling operation for heating the water in the hot water storage tank by the heating means. The control device changes the target hot water temperature in the boiling operation to at least two temperatures, the maximum hot water temperature, which is the highest temperature among the target hot water temperatures that can be set, and the low hot water temperature, which is lower than the maximum hot water temperature. It is configured to be possible. The control device uses the surplus power with the maximum hot water temperature as the target hot water temperature when the power sale of the surplus power excluding the used power from the generated power, which is the power generated by the power generation device, is being suppressed. Perform boiling operation.

According to the present invention, in the boiling operation, when there is sufficient surplus electric power, boiling is performed at once with the maximum hot water temperature as the target hot water temperature. As a result, the surplus power can be used efficiently.

It is a schematic block diagram which shows the hot water storage type hot water supply system of Embodiment 1 of this invention. It is a flowchart of an example of the control of the boiling operation executed by the control device of Embodiment 1 of this invention. It is a flowchart of an example of the control of the boiling operation executed by the control device of Embodiment 2 of this invention. It is a flowchart of an example of the control of the boiling operation executed by the control device of Embodiment 3 of this invention.

Hereinafter, embodiments will be described with reference to the drawings. Common or corresponding elements in the drawings are designated by the same reference numerals to simplify or omit duplicate description.

Embodiment 1.
FIG. 1 is a schematic configuration diagram showing a hot water storage type hot water supply system according to the first embodiment of the present invention. As shown in FIG. 1, the hot water storage type hot water supply system according to the first embodiment includes a hot water storage tank unit 100 having a built-in hot water storage tank 10 and a heat pump unit 101.

The heat pump unit 101 is a heating means that heats water by consuming electric power and operating a heat pump cycle. A compressor 1, a water refrigerant heat exchanger 2, an expansion valve 3, and an air heat exchanger 4 are cyclically connected to the heat pump unit 101 by a refrigerant circulation pipe 5, forming a heat pump cycle. The refrigerant circulation pipe 5 circulates a refrigerant (for example, CO2). The air heat exchanger 4 exchanges heat between the outside air and the refrigerant. The compressor 1 compresses the refrigerant to a high temperature and high pressure. The water-refrigerant heat exchanger 2 is for exchanging heat between the refrigerant flowing through the refrigerant circulation pipe 5 and the water guided from the hot water storage tank unit 100. The expansion valve 3 reduces the pressure of the refrigerant after the heat exchange is completed to a low temperature and a low pressure.

The heating capacity of the heat pump unit 101 is the amount of heat given to water per unit time, and the unit is watts. The heating capacity of the heat pump unit 101 is adjustable. For example, the heating capacity of the heat pump unit 101 may be adjustable by making the operating frequency of the compressor 1 variable. By changing the heating capacity of the heat pump unit 101, the power consumption of the heat pump unit 101 is adjusted.

The hot water storage tank unit 100 and the heat pump unit 101 are connected to each other via an HP going pipe 13, an HP return pipe 14, and electrical wiring (not shown). HP is an abbreviation for heat pump. The HP going pipe 13 connects the lower part of the hot water storage tank 10 and the water inlet of the heat pump unit 101. The HP return pipe 14 connects the hot water outlet of the heat pump unit 101 and the switching valve 12 described later.

The water supply pipe 21 of the hot water storage tank unit 100 connects the water inlet at the bottom of the hot water storage tank 10 to a water source such as water. The water supplied from the water supply pipe 21 is adjusted to a predetermined pressure by a pressure reducing valve (not shown) and then flows into the lower part of the hot water storage tank 10, so that the inside of the hot water storage tank 10 is maintained in a full state.

A hot water supply mixing valve 22 is provided in the hot water storage tank unit 100. A water supply pipe branched from the water supply pipe 21 is connected to the water side inlet of the hot water supply mixing valve 22. The hot water outlet pipe 23 connects the upper part of the hot water storage tank 10 and the hot water side inlet of the hot water supply mixing valve 22. A hot water supply pipe 24 is connected to the outlet of the hot water supply mixing valve 22. The hot water that has passed through the hot water supply pipe 24 is supplied to a hot water supply terminal such as a bathtub, a shower, a sink, and a wash basin.

A switching valve 12 is provided in the hot water storage tank unit 100. The hot water storage pipe 15 connects the outlet of the switching valve 12 and the upper part of the hot water storage tank 10. In the boiling operation, the hot water heated by the heat pump unit 101 flows into the hot water storage tank 10 from the upper part of the hot water storage tank 10 through the hot water storage pipe 15. As a result, in the hot water storage tank 10, a temperature stratification can be formed in which the upper side is high temperature and the lower side is low temperature due to the difference in water density depending on the temperature, and the high temperature hot water is gradually accumulated from the top to the bottom. .. Further, one end of the bypass pipe 16 is connected to the switching valve 12, and the other end of the bypass pipe 16 is the lower part of the hot water storage tank 10 and is connected to a position above the connection position between the heat pump going pipe 13 and the hot water storage tank 10. Has been done. A pump 11 for circulating hot water is arranged in the heat pump going pipe 13.

A control device 17 is provided in the hot water storage tank unit 100. The control device 17 can detect the temperature distribution of hot water in the hot water storage tank 10 based on the outputs of a plurality of hot water storage temperature sensors (not shown) attached to the surface of the hot water storage tank 10 at different heights. As a result, the amount of hot water stored and the amount of heat stored in the hot water storage tank 10 can be detected. The control device 17 may control the start and stop of the boiling operation according to the detected amount of hot water stored or the amount of heat stored in the hot water storage tank 10.

The hot water storage type hot water supply system includes a remote control device 20. The remote control device 20 and the control device 17 can communicate in both directions by wired communication or wireless communication. The control device 17 and the remote control device 20 may be able to communicate with each other via a network. The remote control device 20 is an example of a user interface. The remote controller 20 may be installed on a wall such as a kitchen, a living room, or a bathroom. Alternatively, for example, a mobile information terminal such as a smartphone may be configured to have a function as a user interface such as the remote control device 20. A plurality of remote control devices 20 may be able to communicate with the control device 17. By operating the remote controller 20, the user can remotely control the hot water storage type hot water supply system and make various settings. The control device 17 can acquire various information such as information input by the user via the remote control device 20.

As shown in FIG. 1, a house or facility (hereinafter, collectively referred to as “house”) in which the hot water storage type hot water supply system of the first embodiment is used is provided with a photovoltaic power generation facility 30. .. The photovoltaic power generation facility 30 corresponds to a power generation device that uses renewable energy.

The photovoltaic power generation facility 30 has a photovoltaic power generation panel and a power conditioner connected to the photovoltaic power generation panel. The electric power generated by the photovoltaic power generation panel is converted from direct current to alternating current in the power conditioner, and is transmitted to the distribution board 34 in a state where the voltage and frequency are adjusted. Further, the distribution board 34 is connected to a power system 36 of an electric power company or the like, which is an external power source, and power is supplied from the power system 36. In the embodiment, the electric power supplied from the photovoltaic power generation facility 30 is also referred to as “generated electric power”, and the electric power supplied from the electric power system 36 is also referred to as “system electric power”.

Electric power is supplied to the hot water storage type hot water supply system and other electric devices in the house through the distribution board 34. As a result, the electric equipment including the hot water storage type hot water supply system in the house where the hot water storage type hot water supply system according to the present embodiment is installed can be operated by the generated power or the grid power.

Further, the solar power generation facility 30 supplies (that is, reverse power flow) the surplus power obtained by excluding the power used for the electric equipment in the house from the generated power to the power system 36 via the distribution board 34. It has an electric function.

However, in order to stabilize the balance between supply and demand of electric power, when an electric power company or the like having the electric power system 36 issues an output suppression command to temporarily suppress or stop the reverse power flow to the electric power system 36. There is. Here, suppression of reverse power flow means that, for example, an upper limit value for power sales is set and the amount of power to be reverse power flow is limited to the upper limit value for power sales. It means that it will be completely stopped.

In the present embodiment, when the reverse power flow of the generated power to the power system 36 is not possible due to the output suppression command from the electric power company or the like, and the amount of power to be reverse power flow is set by setting the upper limit value for selling power. The case of being restricted shall be referred to as "output suppression in progress".

However, what kind of restrictions on power sales are included in "output suppression" in the embodiment is not particularly limited, and if power sales are prohibited for some reason, it is set to "output suppression". Can be included. What kind of restrictions on power sales should be included in "output suppression" is set in advance in the control device 17 based on the status of system cooperation with the power system in the area where the hot water storage type hot water supply system is used. It may be an item, or it may be an item appropriately set by the user via the remote controller 20.

Specifically, for example, in the power conditioner of the photovoltaic power generation facility 30, when the voltage on the power system 36 side rises to the specified upper limit of voltage rise suppression, the voltage that suppresses the voltage so that the voltage does not rise any more. It has an ascending suppression function. When this function works, even if there is surplus power, it cannot be reverse-fed to the power system 36 side. Therefore, the restriction of reverse power flow by the output suppression command from the electric power company or the like described above may be set to "output suppression in progress" including such a case.

An energy management device 31 that integrates and manages electrical equipment in a house is connected to the photovoltaic power generation facility 30. The energy management device 31 can measure the amount of power generated by the photovoltaic power generation facility 30 and calculate the surplus power. Further, the energy management device 31 receives the information from the power conditioner or the information during output suppression in which the buying and selling of the generated power is restricted via the Internet or the like. The control device 17 is connected to the energy management device 31 via the communication adapter 32, and can receive information on surplus power calculated by the energy management device 31, information during output suppression, and the like.

As described above, the control device 17 controls the start and stop of the boiling operation. When the boiling operation is executed, for example, the hot water in the hot water storage tank 10 is heated to the target hot water temperature and stored in the heat pump unit 101. Further, particularly in the present embodiment, when there is surplus electric power, the control device 17 utilizes the surplus electric power to execute the boiling operation.

FIG. 2 is a diagram showing an example of control of boiling operation utilizing surplus electric power executed by the control device 17 of the first embodiment in a flowchart. The control of this boiling operation will be described with reference to FIG. It is assumed that the control of FIG. 2 is repeatedly executed at regular control intervals.

In the control shown in FIG. 2, first, in step S102, it is determined whether or not the surplus power is equal to or more than the reference power. As described above, the surplus power is acquired from the information from the energy management device 31. The reference power is a predetermined value stored in the control device 17, and is, for example, 2 kW. The reference power is preferably set to be equal to or higher than the power consumption during boiling operation. As a result, it is possible to use up the surplus power during the boiling operation and to avoid boiling due to the system power. In step S102, if it is determined that the surplus power is equal to or greater than the reference power, the process proceeds to step S104, and if it is determined to be less than the reference power, the process proceeds to step S110.

In step S104, the target hot water temperature at the time of boiling is set to the maximum hot water temperature. Here, the maximum hot water discharge temperature is the highest temperature among the target hot water discharge temperatures that can be set in the boiling operation. An example of a specific maximum hot water temperature is 90 ° C. Since the surplus power is equal to or higher than the reference power in step S102, it is presumed that the boiling operation can be completed at the maximum hot water temperature due to the surplus power. Therefore, in the process of step S104, the heat storage amount of the hot water storage type hot water supply system is maximized by setting the target hot water temperature as the maximum hot water temperature, so that the surplus electric power can be effectively utilized. After that, the process proceeds to step S106 to start boiling.

Next, in step S108, it is determined whether or not the boiling of the entire amount of hot water stored in the hot water storage tank 10 is completed. That is, here, it is determined whether or not the entire amount of hot water stored in the hot water storage tank 10 has been stored by the boiling operation. For example, when the temperature of the hot water in the hot water storage tank detected by the temperature sensor installed at the bottom of the hot water storage tank 10 becomes higher than the target hot water discharge temperature (that is, the maximum hot water discharge temperature), the boiling of the entire amount is completed. It can be determined that the test has been performed.

Normally, the hot water storage tank 10 is maintained in a full state. Therefore, when it is determined in S108 that the boiling of the entire amount is completed, it can be determined that the maximum amount of heat has been stored in the hot water storage tank 10. If it is determined in step S108 that the boiling of the entire amount has been completed, the process proceeds to step S110, and the boiling operation is terminated.

If it is determined in step S108 that the boiling of the entire amount has not been completed, the process of step S108 is repeatedly executed until it is determined that the boiling of the entire amount has been completed.

However, even when it is determined in step S102 that the surplus power is less than the reference power, the process of step S110 is executed. Since the control routine of FIG. 2 is repeatedly executed at regular control intervals, the control routine of FIG. 2 is started while the determination process of step S108 is being repeatedly executed, and the surplus power is used as a reference in step S102. If it is determined that the power is less than the power, the boiling operation is terminated.

As described above, in the present embodiment, when the surplus electric power has a margin for the boiling operation, the boiling operation is started, and at that time, the target hot water temperature is set to the maximum hot water temperature. Set and boil at once. As a result, the surplus power can be utilized efficiently.

In the present embodiment, the configuration for simply ending the boiling operation when the surplus power is not equal to or higher than the reference power has been described. However, in the present embodiment, it is possible to select between a surplus power utilization mode in which the boiling operation is performed by utilizing the surplus power and a grid power utilization mode in which the system power is used for the boiling operation, and the surplus power is used as a reference. When the power is not more than the power, the grid power utilization mode may be selected.

As a method of switching to the selected mode in this case, for example, in the case of a system having a means for switching the electric power supplied to the hot water storage type hot water supply system between the generated electric power and the grid electric power, the electric power is selected. Depending on the mode, the supplied power may be switched between surplus power and grid power.

In addition, the mode switching includes the case where the surplus power utilization mode or the grid power utilization mode is switched as a result by selecting the time zone in which the generated power is supplied and the time zone in which the grid power is supplied. Is done. For example, when the photovoltaic power generation facility 30 using photovoltaic power generation is used as a power generation device as described in the present embodiment, surplus power is not generated during the night time. On the other hand, the unit price of electricity when purchasing grid power (hereinafter referred to as "unit price of power purchase") is often cheaper in the night time zone than in other daytime hours. Therefore, when the surplus power is less than the reference power and the grid power mode is selected, for example, the boiling operation is executed in the night time zone when there is no surplus power and the unit purchase price is low. It may be configured as follows.

Further, for example, even if the surplus power is equal to or higher than the standard power, if the unit price of the generated power is higher than the unit price of the purchased power and the cost merit of the user is greater if the surplus power is sold, the grid power is used. The mode may be selected.

Embodiment 2.
The configuration of the hot water storage type hot water supply system of the second embodiment is the same as that of the hot water storage type hot water supply system shown in FIG. The hot water storage type hot water supply system of the second embodiment is the same as the hot water storage type hot water supply system of the first embodiment except that the boiling operation utilizing the surplus power is executed while the output of the surplus power is restricted. It is the same.

FIG. 3 is a diagram showing an example of control executed by the control device in the hot water storage type hot water supply system of the second embodiment in a flowchart. This control is repeatedly executed at regular control intervals instead of the control of FIG. In the control shown in FIG. 3, first, in step S202, it is determined whether or not the output is currently suppressed. Information on whether or not output suppression is in progress can be obtained via an external network such as the cloud using, for example, the communication adapter 32. Alternatively, the configuration may be such that the information input by the user from the remote controller 20 is obtained. Further, it may be configured to determine that the output is being suppressed based on the state of the power conditioner.

If it is determined in step S202 that the output is being suppressed, the process proceeds to step S102. Since the processes of steps S102 to S110 are the same as those in FIG. 2, the description thereof will be omitted. On the other hand, if it is determined in step S202 that the output is not suppressed, the process proceeds to step S110, the boiling operation is terminated, and the current process is terminated. Alternatively, if it is determined in step S202 that the output is not being suppressed, the control of FIG. 3 may be terminated as it is.

As described above, according to the present embodiment, even if the surplus power is equal to or more than the reference power, the boiling operation is not executed unless the output is suppressed. That is, the boiling operation using the surplus electric power is carried out only while the output is suppressed, and is carried out at once with the maximum hot water discharge temperature as the target hot water discharge temperature. As a result, surplus electric power can be efficiently utilized, and a hot water storage type hot water supply system with high cost merit for the user can be provided.

In this embodiment as well, as described in the first embodiment, the configuration may be such that the surplus power utilization mode and the grid power utilization mode can be switched. In this case, which mode is selected is, for example, the difference between the unit price of generated power and the unit price of power purchased from the grid power, and the difference between the upper limit of power sold and the surplus power during output suppression. It can be decided in consideration. For example, when the unit price of generated power is higher than the unit price of system power purchased during the nighttime, and the upper limit of power sold during output suppression is slightly smaller than the surplus power, surplus power in boiling operation. If the cost merit is reduced due to the decrease in the amount of power sold due to the use of the power grid, the mode can be switched to the grid power use mode.

Embodiment 3.
The configuration of the hot water storage type hot water supply system of the third embodiment is the same as the configuration of the hot water storage type hot water supply system of FIG. The hot water storage type hot water supply system of the third embodiment is the same as the hot water storage type hot water supply system of the first embodiment except that the heating capacity of the heat pump unit 101 and the target hot water discharge temperature are changed according to the magnitude of the surplus electric power. ..

FIG. 4 is a diagram showing an example of control executed by the control device 17 of the hot water storage type hot water supply system according to the third embodiment of the present invention in a flowchart. The control of FIG. 4 is repeatedly executed at regular control intervals instead of the control of FIG.

In the routine of FIG. 4, first, in step S302, it is determined whether or not the surplus power is equal to or greater than the first reference power. Here, the first reference power is set to, for example, equal to or higher than the rated power consumption during the boiling operation of the hot water storage type hot water supply system. The specific value of the rated power consumption is, for example, 2 kW. In step S302, if it is determined that the surplus power is equal to or greater than the first reference power, the process proceeds to step S304, and if it is determined to be less than the first reference power, the process proceeds to step S314. ..

In step S304, the heating capacity of the heat pump unit 101 is set to the rated capacity. Then, the process proceeds to step S104. Since the processes of steps S104 to S110 are the same as the processes of FIG. 2, the description thereof will be omitted.

In step 302, it is determined that the surplus power is less than the first reference power, and when the process proceeds to step S314, it is determined whether or not the surplus power is equal to or more than the second reference power. The second reference power is a value smaller than the first reference power, and for example, the heating capacity of the heat pump unit 101 is set to the power consumption when performing the boiling operation with a low capacity. The specific value is, for example, 1 kW. By setting the second reference power to the power consumption when the boiling operation is performed at a low capacity, it is possible to avoid using up the surplus power when the boiling operation is performed at a low capacity. can.

If it is determined in step S314 that the surplus power is equal to or greater than the second reference power, the process proceeds to step S316. On the other hand, when it is determined that the surplus power is less than the second reference power, the process proceeds to step S110, the current boiling operation is terminated, and the current routine is also terminated once.

In step S316, the boiling operation capacity is set to low capacity. After that, in step S318, the target hot water temperature at the time of boiling is set to a temperature lower than the maximum hot water temperature by a reference value. Here, the reference value is a value that is preset and stored in the control device 17 so that the target hot water temperature becomes an appropriate temperature for boiling at a low capacity. As an example, the maximum hot water temperature is 90 ° C. If so, the reference value is a temperature of about 10 ° C. Since the surplus power is equal to or higher than the second reference power in step S314, it is presumed that the boiling operation can be completed by the surplus power if the target hot water temperature is low. Therefore, in the process of step S314, by setting the target hot water discharge temperature to a temperature lower than the maximum hot water discharge temperature, the maximum heat storage is performed within the range possible with the current surplus power, and the surplus power is effectively utilized. ing.

Next, the process proceeds to step S320, and the boiling operation is started. Next, the process proceeds to step S322, and it is determined whether or not the boiling of the entire amount of hot water stored in the hot water storage tank 10 is completed by boiling. That is, it is determined whether or not the entire amount of hot water stored in the hot water storage tank 10 has been stored at the set target hot water discharge temperature. When it is determined in step S322 that the boiling of all the amount of hot water in the hot water storage tank 10 is completed, the boiling operation is terminated in step S110.

If it is determined in step S322 that the boiling is not completed, the process of step S322 is repeated until the boiling of the entire amount of hot water in the hot water storage tank 10 is completed. However, the control routine of FIG. 4 is repeatedly executed at regular control intervals. Therefore, while the process of step S322 is being repeated, the control routine of FIG. 4 is started, and when it is determined in step S314 that the surplus power is less than the second reference power, the process of step S110 causes boiling. The operation is terminated.

As described above, according to the present embodiment, the reference value for determining whether or not to perform the boiling operation in the surplus power utilization mode is set in two stages of the first reference power and the second reference power. NS. As a result, the amount of heat stored in the hot water storage tank 10 can be increased to the extent possible even when the surplus electric power is insufficient for the boiling operation in which the maximum hot water temperature is set as the target hot water temperature. As a result, the surplus electric power can be utilized more effectively, and the cost merit of the user can be further improved.

Further, in the present embodiment, as in the case of the second embodiment, a configuration may be added in which the boiling operation is executed only during the output suppression in which the sale of surplus power is restricted. In this case, as in the case of the routine of FIG. 3, first, it is determined whether or not the output is being suppressed, and when it is determined that the output is being suppressed, the process proceeds to step S302 and the above-described processing is performed. Are executed sequentially. On the other hand, if it is determined that the output is not being suppressed, the control routine may be configured to be terminated as it is. Alternatively, if it is determined that the output is not being suppressed, the process may be configured to proceed to step S110 and immediately execute the process of ending the boiling operation.

Further, in the present embodiment, when the surplus power is less than the first reference power and more than the second reference power, the capacity is set to be lower than the rated operation, and the power is boiled at a low power consumption and a low target hot water temperature. The case of executing the operation has been described. However, the present invention is not limited to this, and a configuration may be appropriately modified so that the capacity of the heating means is lower when the surplus power is small than when the surplus power is large. As a result, the boiling operation can be performed according to the surplus electric power, and the surplus electric power can be efficiently utilized.

Further, also in the present embodiment, in addition to the surplus utilization mode in which the boiling operation is performed by utilizing the surplus power, a configuration having a grid power utilization mode in which the power from the grid power equipment is used for boiling may be added. .. When the surplus power utilization mode and the grid power utilization mode are provided, the mode with the higher cost merit of the user can be selected. The following configuration can be considered as a specific mode selection method. First, the profit when the surplus power is sold is compared with the cost when the boiling operation is executed in the grid power utilization mode. As a result of the comparison, if the profit obtained by selling the power is larger, the grid power utilization mode is selected. On the other hand, when the cost of executing the boiling operation in the grid power utilization mode is higher, the surplus power utilization mode is selected.

As described in the first embodiment, the method of switching to the selected mode has a configuration in which the power consumption is switched according to the selected mode when there is a means for switching between the use of surplus power and the use of system power. And it is sufficient.

Alternatively, when it is determined that the surplus power is equal to or higher than the first or second reference output, the boiling operation is immediately performed by the control shown in FIG. 4, and as a result, the surplus utilization mode is selected. good. In this case, if the surplus power is less than the second reference output, set a nighttime time zone in which surplus power is unlikely to be generated and the unit purchase price of grid power is cheap, and in this time zone. By automatically starting the boiling operation, the system power utilization mode may be selected as a result.

By adding such a configuration, for example, if the unit price of power sale is high and the upper limit of power sale is slightly smaller than the generated power even if the output is suppressed, the person who sells power up to the upper limit of power sale. However, when the cost merit is higher than that of the boiling operation by utilizing the surplus power, it is possible to switch to the system power use mode, and the merit of the user can be further improved.

In the first to third embodiments, the hot water storage type hot water supply system has been described as having a heat pump as a heating means, but the heating means is not limited to this, and heating may be performed by other means such as a boiler and an electric heater. ..

Further, in the first to third embodiments, a case where a photovoltaic power generation facility that generates electricity by using sunlight as renewable energy is used has been described. However, the renewable energy is not limited to this, and may be an energy source such as solar power, wind power, hydropower, geothermal heat, solar heat, and biomass.

1 Compressor, 2 Water refrigerant heat exchanger, 3 Expansion valve, 4 Air heat exchanger, 5 Coolant circulation piping, 10 Hot water storage tank, 11 Pump, 12 Switching valve, 13 HP Outbound piping, 14 HP Return piping, 15 Hot water storage piping , 16 Bypass pipe, 17 Control device, 20 Remote control device, 21 Water supply piping, 22 Hot water supply mixing valve, 23 Hot water supply piping, 24 Hot water supply piping, 30 Solar power generation equipment, 31 Energy management device, 32 Communication adapter, 34 Distribution board, 36 power system, 100 hot water storage tank unit, 101 heat pump unit

The hot water storage type hot water supply system of the present invention is installed so as to be supplied with power from a grid power facility and a power generation device connected to the grid power facility and generating power by using renewable energy. The hot water storage type hot water supply system includes a hot water storage tank, a heating means for heating water by consuming electric power, and a control device for controlling a boiling operation for heating the water in the hot water storage tank by the heating means. The control device changes the target hot water temperature in the boiling operation to at least two temperatures, the maximum hot water temperature, which is the highest temperature among the target hot water temperatures that can be set, and the low hot water temperature, which is lower than the maximum hot water temperature. It is configured to be possible. The control device uses the surplus power with the maximum hot water temperature as the target hot water temperature when the sale of surplus power excluding the used power from the generated power, which is the power generated by the power generation device, is being suppressed. If the boiling operation is executed and the output of the generated power is not suppressed, the boiling operation using the surplus power with the maximum hot water temperature as the target hot water temperature is not executed.

Claims (7)

It is applied to a hot water storage type hot water supply system that is installed so as to be supplied with power from a grid power facility, a power generation device connected to the grid power facility and generated by using renewable energy, and so on.
Hot water storage tank and
A heating means that consumes electricity to heat water,
A control device that controls a boiling operation for heating the water in the hot water storage tank by the heating means, and
With
The control device is
The target hot water temperature in the boiling operation can be changed to at least two temperatures, the maximum hot water temperature which is the highest temperature among the target hot water temperatures that can be set, and the low hot water temperature lower than the maximum hot water temperature. Configured and
When the sale of surplus power excluding the power used from the generated power, which is the power generated by the power generation device, is being suppressed, the surplus power is used with the maximum hot water temperature as the target hot water temperature. And execute the boiling operation,
A hot water storage type hot water supply system that is characterized by this. The hot water storage type hot water supply system according to claim 1, wherein the control device does not execute the boiling operation when the sales of the generated power are not restricted and the output is not suppressed. The control device is used in the boiling operation.
The surplus power utilization mode in which the heating means consumes the surplus power to heat water,
A system power utilization mode in which the heating means consumes the system power supplied from the system power facility to heat water.
The hot water storage type hot water supply system according to claim 1 or 2, wherein any of the modes can be selected. The control device is
A claim characterized in that the surplus power utilization mode is selected only when the surplus power is equal to or higher than the reference power which is the power required to perform the boiling operation with the maximum hot water temperature as the target hot water temperature. The hot water storage type hot water supply system according to Item 3. The control device is
The hot water storage type hot water supply system according to any one of claims 1 to 4, wherein the heating capacity of the heating means is set according to the electric energy of the surplus electric power. The control device is
When the amount of surplus power is lower than the rated power consumption of the heating means, the heating capacity of the heating means is set to a capacity lower than that during the rated operation, and the boiling is performed with less power consumption than during the rated operation. The hot water storage type hot water supply system according to claim 5, wherein the operation is performed. The control device is
When the electric energy of the surplus power is lower than the rated power consumption of the heating means, the heating capacity of the heating means is set to a capacity lower than that during the rated operation.
The hot water storage type hot water supply system according to claim 5 or 6, wherein the boiling operation is executed with the target hot water discharge temperature set to a temperature lower than the maximum hot water discharge temperature.

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