JP7116907B2 - hot water storage system - Google Patents

Description

The present invention relates to a hot water storage and hot water supply system that is equipped with a heat pump heat source and an auxiliary heat source and is operated by electric power from a power generator for household use that utilizes a commercial power source and sunlight, and in particular, according to the hot water supply usage situation that has been learned and stored. The present invention relates to a hot water storage and hot water supply system that predicts future hot water supply use based on the prediction and performs hot water storage operation based on the prediction.

2. Description of the Related Art Conventionally, a hot water storage and hot water supply apparatus equipped with a heat pump heat source for heating hot water to be used for hot water supply and storing it in a hot water storage tank and a combustion auxiliary heat source for heating hot water when hot water is used has been widely used. ing. Since the operating efficiency of the heat pump heat source machine is generally superior to that of the auxiliary heat source machine, such a hot water storage/hot water supply apparatus predicts future hot water supply use based on the learned and stored hot water use status, and determines the hot water supply use. In order to store hot water required for hot water supply in the hot water storage tank, the hot water storage operation using the heat pump heat source is configured to be performed.

On the other hand, households equipped with power generators that use solar or wind power supply the generated power to the household's power consumers, and if the generated power exceeds the power consumption of the household, the surplus power is used. By selling electricity to the outside, household energy costs are reduced. Since the selling price of this power is on a downward trend and the difference between it and the price of commercial power is getting smaller, there is a need to give priority to household use over selling power. For example, as in Patent Document 1, in a domestic hot water storage and hot water supply device equipped with a photovoltaic power generation device and an electricity storage device, the remaining amount after subtracting the future predicted power consumption from the total of the future predicted power generation amount and the remaining power amount of the power storage device There is known a technique of changing the stored hot water temperature according to the amount of surplus electric power obtained and storing hot water using the surplus electric power.

JP 2017-36842 A

However, in the technique disclosed in Patent Document 1, hot water is stored until the hot water storage tank is filled with hot water at the hot water storage temperature. In addition, since surplus power cannot be used to heat hot water that is not used for hot water supply and sold, there is room for improvement in reducing energy costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hot water storage and hot water supply system that stores the amount of heat required for hot water supply before using the hot water and uses the surplus electric power of the power generator for the stored hot water to reduce the energy cost.

The hot water storage and hot water supply system according to claim 1 comprises a heat pump heat source device driven by electric power, a hot water storage tank for storing hot water heated by the heat pump heat source device, an auxiliary heat source device for reheating the hot water in the hot water storage tank, and power generation . and a control means for controlling the hot water storage operation so as to store the required amount of heat corresponding to the future hot water consumption amount predicted based on the learned and stored hot water consumption before using the hot water supply. In a hot water storage and hot water supply system in which power measuring means for measuring power and household power consumption are communicably connected, the control means learns and stores information on surplus power obtained by subtracting household power consumption from the power generated by the power generator. a surplus power prediction function for predicting future surplus power by using the predicted surplus power; setting means for setting a permission time zone for permitting the hot water storage operation using the predicted surplus power; When there is surplus electricity generated, the heat pump heat source machine is operated with electric power from the power generation device, and in other cases, the heat pump heat source machine is operated with commercial power, and the control means comprises: Predicting the hot water supply start time, calculating the necessary time required to store the required amount of hot water with the heating capacity of the heat pump heat source device limited so as not to exceed the predicted surplus power, and calculating the required time from the hot water supply start time It is characterized by setting the start time of the hot water storage operation advanced by the necessary time.

According to the above configuration, the required amount of heat can be stored before the hot water supply is used, and by maximally using the surplus power for the hot water storage operation of the required amount of heat, the electric power of the commercial power supply used for the hot water storage operation can be reduced and the energy can be saved. Cost can be reduced.

In addition, it is possible to set the time periods when household power consumption is low as permitted time periods, and during the permitted time periods when there is a large amount of surplus power, hot water storage operation is performed to maximize the use of surplus power, thereby reducing the use of commercial power supply. can do.

According to the hot water storage and hot water supply system of the present invention, the amount of heat necessary for hot water supply can be stored before hot water supply is used, and the surplus electric power of the power generation device can be used for the hot water storage, thereby reducing the energy cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole hot-water storage hot-water supply system structure which concerns on the Example of this invention. It is a figure which shows the structure of the heat pump heat-source equipment and hot-water storage hot-water supply unit which concern on the Example of this invention. 4 is a flow chart of a hot water storage operation with a required amount of heat according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of storing the required amount of heat with the maximum heating capacity of the heat pump heat source equipment; FIG. 10 is a diagram showing an example of storing the required amount of heat with a limited heating capacity based on surplus electric power;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on an Example.

First, based on FIGS. 1 and 2, the overall configuration of a hot water storage and hot water supply system 1 of the present invention will be described.
The hot water storage and hot water supply system 1 includes a heat pump heat source device 2, a hot water storage and hot water supply unit 3, and a solar power generation device 4 as a household power generation device. The hot water storage and hot water supply unit 3 includes a hot water storage tank 11 for storing hot water heated by the heat pump heat source device 2 in the hot water storage operation, a combustion auxiliary heat source device 12 for reheating the hot water in the hot water storage tank 11, and future hot water supply use. A control unit 13 (control means) or the like is provided for controlling the hot water storage operation so as to predict and store the required amount of heat in the hot water storage tank 11 before hot water supply is used. The heat pump heat source device 2 absorbs heat from the outside air to heat hot water in the hot water storage tank 11 based on a hot water storage operation command from the control unit 13, and returns the heated hot water to the hot water storage tank 11 for storage.

The photovoltaic power generation device 4 includes a junction box 6 connected to combine the DC power generated by the solar panel 5 that generates power from sunlight, and for converting the DC power from the junction box 6 into AC power (generated power). and a power distribution board 8 connected so that the power generated by the power conditioner 7 can be distributed to the points of use in the home. The distribution board 8 also distributes AC power (commercial power) from the commercial power supply line 9 to locations of use in the home. This distribution board 8 is also a power measuring means for measuring the power generated by the photovoltaic power generation device 4 and the power used by the household. The power generated by the power conditioner 7 is distributed in the home, and the surplus power is sent from the distribution board 8 to the outside through the commercial power line 9 and sold.

A part of the electric power distributed from the distribution board 8 is supplied to the hot water storage and hot water supply unit 3 via the power supply line 3a, and is supplied from the hot water storage and hot water supply unit 3 to the heat pump heat source device 2 via the power supply line 2a. The heat pump heat source device 2 and the hot water storage and hot water supply unit 3 are driven using the generated power and the commercial power distributed from the distribution board 8, either alone or in combination.

The hot water storage unit 3 uses the hot water stored in the hot water storage tank 11 in the hot water storage operation to supply hot water and fill the bathtub 29 with hot water. In addition, in the case of hot water supply at a temperature at which the hot water in the hot water storage tank 11 cannot be used or reheating operation of the bathtub 29, the hot water heated by burning fuel in the auxiliary heat source device 12 is used for hot water supply or reheating operation.

A hot water discharge passage 14 for discharging hot water stored in the hot water storage tank 11 is connected to the upper portion of the hot water storage tank 11 . The outlet hot water passage 14 is connected to a hot water mixing valve 15 and has a hot water temperature sensor 14 a for detecting the temperature of hot water supplied to the hot water mixing valve 15 . A water supply passage 16 for supplying clean water from a clean water source to the hot water storage tank 11 is connected to the lower portion of the hot water storage tank 11 . The water supply passage 16 is provided with a water supply temperature sensor 16a for detecting the temperature of tap water.

The hot water mixing valve 15 mixes the hot water in the hot water outlet passage 14 and the clean water in the bypass passage 17 branched from the water supply passage 16 and connected to the hot water mixing valve 15 so as to supply clean water. By adjusting the mixing ratio of the hot water mixing valve 15, the hot water supply temperature is adjusted. A hot water supply passage 18 is connected to the hot water mixing valve 15, and the hot water mixed by the hot water mixing valve 15 flows through the hot water supply passage 18 during hot water supply and is supplied to a hot water supply valve (not shown) or the like, and is supplied from the hot water supply passage 18 when hot water is filled. The hot water is supplied to the bathtub 29 through the hot water filling passage 19 branched and connected to the reheating circuit 32 . The hot water supply passage 18 is provided with a hot water supply temperature sensor 18a for detecting the temperature of the hot water supply.

An upstream heating passage 21 a that supplies hot water to the heat pump heat source device 2 is connected to the lower portion of the hot water storage tank 11 , and a downstream heating passage 21 b that returns hot water heated by the heat pump heat source device 2 to the hot water storage tank 11 is connected to an upper portion of the hot water storage tank 11 . , and a circulation heating circuit 21 in which hot water can be circulated between the hot water storage tank 11 and the heat pump heat source device 2 by a boiling pump 22 is formed. In the hot water storage operation, hot water in the hot water storage tank 11 is heated to a hot water storage temperature set by the heat pump heat source device 2 and is stored from the top of the hot water storage tank 11 . A temperature sensor 23a is provided in the upstream heating passage 21a, and a temperature sensor 23b is provided in the downstream heating passage 21b.

A plurality of stored hot water temperature sensors 11a to 11d for detecting the temperature and amount of hot water in the hot water storage tank 11 are provided on the outer periphery of the hot water storage tank 11 at predetermined intervals in the vertical direction. These hot water temperature sensors 11a to 11d and the hot water tank 11 are covered with a heat insulating material (not shown) that reduces heat radiation from the hot water tank 11. As shown in FIG.

An auxiliary heating passage 24 for heating the hot water in the hot water storage tank 11 with the auxiliary heat source machine 12 is branched from the hot water discharge passage 14 and connected to the auxiliary heat source machine 12 . An auxiliary hot water discharge passage 25 for discharging hot water heated by the auxiliary heat source machine 12 is connected to the hot water discharge passage 14 on the downstream side of the branch portion of the auxiliary heating passage 24 via a water proportional valve 26 . The auxiliary heating passage 24 is provided with a three-way valve 27 and a pump 28 for sending hot water to the auxiliary heat source machine 12 .

A heat exchanger passage 30 branched from the auxiliary hot water outlet passage 25 is connected to a three-way valve 27 . The three-way valve 27 is switched so that hot water in the hot water storage tank 11 or hot water in the heat exchanger passage 30 can be supplied to the auxiliary heat source device 12 . The heat exchanger passage 30 is provided with a heat exchanger 30a and an on-off valve 30b. A branch passage portion 16 b branched from the water supply passage 16 is connected between the on-off valve 30 b of the heat exchanger passage 30 and the three-way valve 27 . The heat exchanger 30 a is used for a reheating operation in which the hot water in the bathtub 29 flowing through the reheating circuit 32 is heated by the operation of the reheating pump 31 and the hot water heated by the auxiliary heat source device 12 .

The heat pump heat source device 2 includes a heat pump circuit 37 in which a compressor 33, a condensing heat exchanger 34, an expansion valve 35, and an evaporative heat exchanger 36 are connected by refrigerant pipes. The heat pump heat source device 2 compresses the refrigerant enclosed in the refrigerant pipe with the compressor 33 to raise the temperature, and heats the hot water flowing through the circulation heating circuit 21 by exchanging heat with the high-temperature refrigerant in the condensation heat exchanger 34. and stores hot water in the hot water storage tank 11. After the heat exchange, the refrigerant expands in the expansion valve 35 to be lower in temperature than the outside air, absorbs heat from the outside air in the evaporative heat exchanger 36 , and is introduced into the compressor 33 again.

The evaporative heat exchanger 36 includes an outside air temperature sensor 36a for detecting outside air temperature and a blower 36b. The heat pump heat source device 2 also includes an auxiliary control section 38 that controls the compressor 33, the expansion valve 35, the blower 36b, and the like. The auxiliary control unit 38 is communicably connected to the control unit 13 that is the main control means of the hot water storage and hot water supply system 1 , and controls the heat pump heat source device 2 based on commands from the control unit 13 .

A distribution board 8 is communicably connected to the control unit 13, and the control unit 13 receives power information such as generated power and household power consumption, and stores surplus power that can be sold (generated power minus used power Remaining power) information is obtained. The control unit 13 is also connected to an operation terminal 13a (setting means) for various settings and operations such as setting of hot water supply temperature by the user.

The control unit 13 controls the hot water supply operation and the like based on detection signals from the outlet hot water temperature sensor 14a and the like, as well as the amount of hot water supplied in the past, various temperatures, the hot water supply usage status such as the hot water supply start time, and past power information. etc. are learned and memorized. Then, it has a hot water supply usage prediction function for predicting future hot water supply usage based on this hot water supply usage status, and a surplus power prediction function for predicting future surplus power based on this power information. Then, this hot water supply usage prediction and surplus power prediction are repeatedly performed at predetermined time intervals (for example, every 5 minutes).

In predicting the hot water supply usage, the control unit 13 calculates the required heat quantity corresponding to the predicted hot water supply usage amount. In addition, in order to maximize the use of surplus power and suppress the use of commercial power, the heating capacity of the heat pump heat source device 2 in the hot water storage operation using the surplus power is reduced so as not to exceed the predicted surplus power in the prediction of the surplus power. Set limits. At this time, the operation terminal 13a sets the permitted time period so that the hot water storage operation using the surplus power can be performed only during the permitted time period when household power consumption is low. Set heating capacity based on predictions. If the required amount of hot water can be stored with the set heating capacity by the predicted hot water supply start time, the time required to store the required amount of heat with the set heating capacity will be advanced from the predicted hot water supply start time. Set the operation start time.

On the other hand, if the required amount of hot water cannot be stored by the predicted hot water supply start time with the set heating capacity, the shortest time required to store the required amount of hot water with the maximum heating capacity of the heat pump heat source device 2 from the predicted hot water supply start time. Set the hot water storage operation start time to the time advanced by The control unit 13 starts the hot water storage operation at the set hot water storage operation start time, and controls the hot water storage operation so that the required amount of hot water is stored by the predicted hot water supply use start time. The control of the hot water storage operation based on the hot water supply usage prediction by the control unit 13 will be described with reference to the flowchart of FIG. Si (i=1, 2, . . . ) in the figure represents steps.

First, in S1, based on the learned and stored hot water supply usage condition, the required heat amount corresponding to the future hot water supply usage amount and the hot water supply start time are predicted, and the process proceeds to S2. Next, in S2, the set permitted time period is read, and the process proceeds to S3. In S3, the current power information is acquired, and the process proceeds to S4. At this time, future surplus power is predicted based on the learned and stored power information.

Next, in S4, the heating capacity of the heat pump heat source device 2 for hot water storage operation using surplus power is set, and the process proceeds to S5. Although the heating capacity may be set based on the power information acquired in S3, it is preferable to set the heating capacity based on the prediction of the surplus power. For example, even if there is surplus power that can be set to the maximum heating capacity at present, if the situation of surplus power that limits the heating capacity continues intermittently before this, it is predicted that the same situation of surplus power will continue in the future. This is because the use of commercial power can be expected to be reduced by setting the limited heating capacity based on the above.

Next, in S5, the required time required for storing the required amount of hot water by the hot water storage operation with the set heating capacity is calculated, and the process proceeds to S6. The required time may be corrected in consideration of heat dissipation. Next, in S6, it is determined whether or not to execute the hot water storage operation using the surplus electric power. Specifically, if the time obtained by advancing the required time calculated in S5 from the hot water supply use start time predicted in S1 is within the permitted time period, the determination is made Yes and the process proceeds to S7, and if not, the determination is made No and the process proceeds to S10. proceed to Even if the calculated time is within the permitted time period, if the heating capacity (for example, less than 1 kW) is such that the heat pump heat source unit 2 cannot be efficiently driven due to a small amount of surplus power, the hot water storage operation using the surplus power is performed. may not be executed.

Next, in S7, the time calculated in S6 (the time calculated in S5 by the required time calculated in S5 from the time calculated in S1) is set as the start time of the hot water storage operation using the surplus electric power, and the process proceeds to S8. . Then, in S8, if the hot water storage operation using the surplus electric power reaches the start time before the next hot water supply usage prediction timing, the process proceeds to S9 to execute the hot water storage operation using the surplus electric power, and if the start time does not come, S1. back to

Next, in S9, the hot water storage operation using the surplus electric power is executed, and when the required amount of hot water has been stored, the hot water storage operation ends. At this time, the heating capacity of the heat pump heat source unit 2 is the heating capacity set in S4. This heating capacity is maintained until the end of the hot water storage operation. When the surplus power is temporarily reduced due to weather or the like, commercial power is also used to maintain the heating capacity of the heat pump heat source device 2 .

On the other hand, if the determination in S6 is No, in S10, the hot water storage operation start time is set to a time advanced from the hot water supply use start time predicted in S1 by the shortest time required to store the required amount of hot water with the maximum heating capacity of the heat pump heat source device 2. is set, and the process proceeds to S11. In S11, if the start time comes before the timing of the next hot water supply use prediction, the process proceeds to S12, and if the start time does not come, the process returns to S1. Next, in S12, the hot water storage operation is performed with the maximum heating capacity of the heat pump heat source device 2 to store the necessary amount of hot water, and the operation ends. Even in the hot water storage operation at the maximum heating capacity, if there is surplus power that can be used together with the commercial power, it is used together.

The hot water storage operation based on the prediction of hot water supply usage will be described with reference to FIGS. 4 and 5. FIG. In the figure, the vertical axis represents the heating capacity, the horizontal axis represents the time, and the rectangular area represents the required amount of heat. For ease of understanding, assume that the maximum heating capacity of the heat pump heat source device 2 is 3 kW, the predicted required amount of heat is 6 kWh, and the predicted hot water supply start time is 17:00. The permitted time period is set from 13:00 to 16:00 in FIG.

In FIG. 4, the hot water storage operation start time is set to 15:00 so that the hot water storage operation is completed at the predicted hot water supply usage start time of 17:00 by executing the hot water storage operation at the maximum heating capacity of the heat pump heat source device 2. have set. When the hot water storage operation using surplus power is not executed due to insufficient surplus power or the permitted time period is not set close to the hot water supply start time, the predicted required heat amount (rectangular part) is set to the maximum This is an example of storing hot water in the hot water storage operation of the heating capacity.

FIG. 5 shows an example in which the hot water storage operation start time is set to 14:00 so that the hot water storage of the required amount of heat is completed before the hot water supply use start time predicted by the hot water storage operation using the surplus electric power. When limiting the heating capacity of the heat pump heat source unit 2 to, for example, 2 kW in order to maximize the use of surplus power and suppress the use of commercial power, the hot water storage operation using the surplus power is started at 14:00 and the predicted hot water supply use is started. By 17:00 of the time, hot water storage of the necessary heat amount is completed.

As described above, the hot water storage and hot water supply system 1 of the present invention can store the required amount of heat before using the hot water supply based on the prediction of hot water supply use, and can maximize the use of surplus power for the hot water storage operation of the required amount of heat. can. Therefore, commercial power used for hot water storage operation can be reduced, and energy costs can be reduced. In addition, it is possible to set a time period in which household power consumption is low as the permitted time period, and perform hot water storage operation that maximizes the use of surplus power during the permitted time period in which there is a large amount of surplus power, thereby reducing the use of commercial power. In addition, the prediction of surplus power is used to set the heating capacity for hot water storage operation using surplus power and to calculate the required time. can be improved.

In addition, those skilled in the art can implement various modifications to the above embodiment without departing from the scope of the present invention, and the present invention includes such modifications.

1: hot water storage and hot water supply system 2: heat pump heat source device 3: hot water storage and hot water supply unit 4: solar power generation device 8: distribution board (power measuring means)
9: Commercial power line 11: Hot water storage tank 12: Auxiliary heat source device 13: Control unit (control means)
13a: operation terminal (setting means)

Claims (1)

A heat pump heat source device driven by electric power, a hot water storage tank for storing hot water heated by the heat pump heat source device, an auxiliary heat source device for reheating the hot water in the hot water storage tank,a power generator;A control means is provided for controlling the hot water storage operation so as to store the necessary amount of heat corresponding to the future hot water consumption amount predicted based on the learned and stored hot water consumption before using the hot water supply. In a hot water storage and hot water supply system in which a power measuring means for measuring the power used is communicably connected,
The control means has a surplus power prediction function for predicting future surplus power by learning and storing information on surplus power obtained by subtracting household power from the power generated by the power generator,
setting means for setting a permitted time zone for permitting the hot water storage operation using the predicted surplus electric power;
If there is surplus power predicted during the permitted time period, the heat pump heat source machine is operated with power from the power generation device, and in other cases, the heat pump heat source machine is operated with commercial power. ,
The control means predicts a hot water supply use start time, andsaid predictedsurplus powerso as not to exceedA required time required for storing the required amount of hot water is calculated with the limited heating capacity of the heat pump heat source device, and a start time of the hot water storage operation is set by advancing the required time from the hot water supply use start time. hot water system.

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