JP7640348B2 - Energy Supply System - Google Patents

Description

This disclosure relates to an energy supply system and a control device.

A system is known that can promote self-consumption of electricity by giving priority to the supply of electricity from storage batteries and solar power generation over fuel cell power in response to electricity demand (see, for example, Patent Document 1).

JP 2020-58102 A

In general, a system equipped with a storage battery that charges surplus electricity generated by solar power can promote self-consumption of electricity generated by solar power. It is required to promote self-consumption of electricity generated by solar power regardless of the charge state of the storage battery or even if there is no storage battery.

The objective of this disclosure is to provide an energy supply system and control device that can promote self-consumption of electricity generated from renewable energy sources.

An energy supply system according to one embodiment of the present disclosure includes an electric water heater and a plurality of gas water heaters to which hot water is supplied from the electric water heater. The plurality of gas water heaters are configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility. The electric water heater operates using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, heats pre-heated water, and supplies heated water at a first temperature or higher to each of the gas water heaters.

A control device according to one embodiment of the present disclosure controls each of a plurality of mixing valves that supply hot water to a gas water heater that is configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility to a set temperature. Each of the mixing valves mixes heated water at a first temperature or higher supplied by an electric water heater that operates using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities and heats the pre-heated water, and supplies the pre-heated water to the gas water heater.

The energy supply system and control device according to one embodiment of the present disclosure promote self-consumption of electricity generated from renewable energy sources.

1 is a block diagram showing an example of the configuration of power wiring of an energy supply system according to an embodiment. FIG. 2 is a block diagram showing an example of the configuration of gas piping and water supply piping of an energy supply system according to one embodiment. FIG.

(Configuration example of energy supply system 1)
An energy supply system 1 according to one embodiment is installed in a complex consumer facility including a plurality of consumer facilities. The complex consumer facility may be an apartment house 4 (see FIG. 1). When the complex consumer facility is an apartment house 4, the complex consumer facility may include, as consumer facilities, each of the plurality of dwelling units 2 (see FIG. 1) of the apartment house 4, or may include a common area 3 (see FIG. 1) of the apartment house 4. The complex consumer facility may be a commercial facility including a store as a consumer facility. Hereinafter, an example of an embodiment will be described assuming that the complex consumer facility is an apartment house 4.

The apartment complex 4 may be in various forms, such as a condominium, an apartment, or a maisonette. The apartment complex 4 may be managed by a management entity. The management entity of the apartment complex 4 may be the owner of the apartment complex 4 or a business operator that manages the apartment complex 4. The management entity of the apartment complex 4 may enter into individual occupancy contracts with the residents of each dwelling unit 2.

<Electricity supply line>
1 , an energy supply system 1 according to one embodiment is connected to a power grid 50 that supplies electric power. The energy supply system 1 is connected to the power grid 50 via a collective trading meter 45. The collective trading meter 45 measures the amount of electric power that the energy supply system 1 receives from the power grid 50. The collective trading meter 45 may also measure the amount of electric power that flows back from the energy supply system 1 to the power grid 50.

The energy supply system 1 includes an electric water heater 43 installed in the common area 3. The electric water heater 43 may be configured to include equipment that heats water using various methods, such as a heat pump method. The electric water heater 43 also includes a tank that stores heated water.

The energy supply system 1 includes a power load 40 that consumes power received from a power grid 50. The power load 40 includes a shared load 41 installed in the common area 3 and a dwelling load 42 installed in the dwelling 2. The energy supply system 1 further includes a shared meter 47, although this is not essential. The shared meter 47 measures the amount of power supplied to the shared load 41 installed in the common area 3. The shared meter 47 is also connected to an electric water heater 43 installed in the common area 3 and measures the amount of power supplied to the electric water heater 43. The energy supply system 1 further includes a dwelling meter 46, although this is not essential. The dwelling meter 46 measures the amount of power supplied to the dwelling load 42 installed in the dwelling 2.

The shared load 41 is an electric power load 40 provided in the common area 3 of the apartment building 4. The common area 3 may be, for example, a corridor or staircase of the apartment building 4. The shared load 41 may include equipment provided in the common area 3, such as lighting fixtures such as outdoor lights, septic tank blower power supplies, emergency equipment such as fire alarms, and other equipment such as air conditioning equipment. The dwelling unit load 42 is an electric power load 40 provided in each dwelling unit 2 of the apartment building 4, and may be, for example, electrical equipment such as lighting fixtures, refrigerators, televisions, or air conditioners used in each dwelling unit 2. The apartment building 4 includes multiple dwelling units 2. Each dwelling unit 2 is provided with a dwelling unit load 42. In other words, the apartment building 4 is provided with multiple dwelling unit loads 42.

The energy supply system 1 further includes a distributed power source 60. The distributed power source 60 includes a photovoltaic power generation facility (hereinafter also referred to as PV) 62 and a power conditioner (hereinafter also referred to as PCS) 61. The PV 62 may be replaced with other renewable energy power generation facilities such as wind power generation facilities, or may be used in combination with the PV 62. The PCS 61 controls the power output from the PV 62 by converting the DC power output from the PV 62 to AC power, for example. The PCS 61 may include an inverter or a converter. The distributed power source 60 may include a storage battery and a fuel cell. The number of the PV 62 and the PCS 61 is not limited to one, and may be two or more. For example, the PV 62 may be provided separately on the roof of the apartment building 4, the roof of the parking lot of the apartment building 4, or within the premises of the apartment building 4.

In the energy supply system 1 according to this embodiment, the amount of electricity received from the power grid 50 is measured by the collective transaction meter 45. In this case, the management entity of the apartment building 4 concludes a collective power receiving contract with an electric power supplier that supplies electricity from the power grid 50. The electric power supplier supplies electricity from the power grid 50 to the apartment building 4 based on the collective power receiving contract. The electric power load 40 included in the apartment building 4 consumes the collectively received electricity. The collective transaction meter 45 measures the amount of electricity supplied from the power grid 50 to the apartment building 4. The collective transaction meter 45 is a certified meter. The electric power supplier manages the collective transaction meter 45 and obtains the measurement results from the collective transaction meter 45. The electric power supplier calculates an electricity fee corresponding to the total power consumption of the apartment building 4 based on the measurement results of the collective transaction meter 45. The electric power supplier charges the electricity fee calculated based on the measurement results of the collective transaction meter 45 to the management entity of the apartment building 4. The management entity of the apartment complex 4 may bill the residents of each dwelling unit 2 for electricity based on the measurement results of the amount of power consumed by each dwelling unit load 42 by the dwelling unit meter 46, or may bill the residents of each dwelling unit 2 for electricity based on other criteria.

When the management entity of the apartment building 4 enters into a lump-sum power receiving contract, either a high-voltage lump-sum power receiving contract or a low-voltage lump-sum power receiving contract is selected. A high-voltage lump-sum power receiving contract is a contract for receiving electricity collectively with an electrical capacity equal to or greater than a predetermined value. A low-voltage lump-sum power receiving contract is a contract for receiving electricity collectively with an electrical capacity less than a predetermined value. The predetermined value is determined appropriately by the electric power company. The predetermined value may be, for example, 50 kW. The management entity of the apartment building 4 may enter into either a high-voltage lump-sum power receiving contract or a low-voltage lump-sum power receiving contract based on the number of dwelling units 2 of the apartment building 4. Regardless of whether a high-voltage lump-sum power receiving contract or a low-voltage lump-sum power receiving contract is entered into, peak power consumption can be cut by leveling out the power consumption of the entire apartment building 4. As a result, the management entity of the apartment building 4 can enjoy the benefit of a reduction in the unit price of electricity due to peak power consumption cuts. By the management entity of the apartment building 4 entering into a lump-sum power receiving contract, the residents of each dwelling unit 2 do not have to go through the trouble of entering into a power receiving contract. When the apartment building 4 is equipped with a distributed power source 60, the power loads 40 of the apartment building 4 as a whole receive power from the distributed power source 60. By leveling out the power consumption, the power loads 40 of the apartment building 4 can constantly consume power from the distributed power source 60. As a result, self-consumption can be promoted.

The energy supply system 1 may be provided with a calibration meter as the shared meter 47 and the dwelling meter 46. In this case, the amount of electricity received from the power grid 50 is measured by the shared meter 47 and the dwelling meter 46. The residents of each dwelling unit 2 of the apartment building 4 may enter into a power receiving contract for the dwelling unit load 42 installed in each dwelling unit 2 with the management entity of the apartment building 4. The management entity of the apartment building 4 bills the residents of each dwelling unit 2 for electricity charges calculated based on the measurement results of the power consumption of the dwelling unit load 42 by the dwelling unit meter 46. The management entity of the apartment building 4 may also bill the residents of each dwelling unit 2 for electricity charges calculated based on the measurement results of the power consumption of the shared load 41 and the electric water heater 43 by the shared meter 47 ... a fixed electricity charge, regardless of the measurement results of the power consumption, or the charge may be included in the rent.

<Gas and water supply lines>
As shown in Fig. 2, the energy supply system 1 according to one embodiment is further connected to a gas supply source 20 that supplies gas and a water supply source 30 that supplies water. The water supply source 30 includes a water supply system. The water supply source 30 may include various other water sources, such as a well or spring water. In Fig. 2, the gas supply line is represented by a dashed line. The water supply line is represented by a solid line.

The energy supply system 1 controls the temperature of water and supplies it to each consumer facility. In this embodiment, the water supplied from the gas water heater 24 to the hot water tap 36 of each dwelling unit 2 is called hot water. In addition, the water present in the piping until it is supplied to the gas water heater 24 is distinguished by different names depending on the location of the water. The water supplied from the water supply source 30 to the electric water heater 43 and the water supplied from the water supply source 30 to the mixing valve 34 are called pre-heated water. The water generated by heating the pre-heated water with the electric water heater 43 and supplied to the mixing valve 34 is called post-heated water. In other words, the electric water heater 43 heats the pre-heated water to generate post-heated water. In addition, the electric water heater 43 has a tank for storing the post-heated water. The electric water heater 43 controls the heating of the pre-heated water so that the temperature of the post-heated water discharged from the tank is equal to or higher than the first temperature. The electric water heater 43 may mix pre-heated water with post-heated water and discharge the water, provided that the temperature of the post-heated water discharged from the tank is kept at or above the first temperature. The water generated by mixing the pre-heated water and the post-heated water in the mixing valve 34 and supplied to the gas water heater 24 is called mixed water. In other words, the mixing valve 34 generates mixed water.

The following describes the configuration for supplying hot water generated from unheated water supplied from the water supply source 30 to the hot water tap 36.

The energy supply system 1 includes a gas water heater 24 connected to a gas supply source 20. The energy supply system 1 also includes a mixing valve 34 that sends at least one of heated water supplied from the electric water heater 43 and pre-heated water supplied from the water supply source 30 to the gas water heater 24. The heated water supplied from the electric water heater 43 is mixed with pre-heated water in the mixing valve 34. That is, the mixing valve 34 generates mixed water by mixing the heated water and the pre-heated water. The temperature of the mixed water is controlled to a second temperature lower than the first temperature. The mixing valve 34 may mix the heated water supplied from the electric water heater 43 and the pre-heated water supplied from the water supply source 30 at a predetermined ratio and supply the mixed water to the gas water heater 24. The mixing valve 34 may supply only the heated water supplied from the electric water heater 43 to the gas water heater 24. The mixing valve 34 may supply only pre-heated water supplied from the water supply source 30 to the gas water heater 24. The mixing valve 34 is controlled by the control device 10 described below. The mixing valve 34 may be configured as, for example, an electromagnetic valve that can automatically change the mixing ratio of pre-heated water and post-heated water, or may be configured as a pressure valve.

The mixing valve 34 may be connected to the water supply source 30 via a water meter 31. The water meter 31 measures the amount of pre-heated water supplied from the water supply source 30 to the gas water heater 24 via the mixing valve 34. The water meter 31 may also measure the amount of pre-heated water supplied to the faucet of each dwelling unit 2 without passing through the gas water heater 24.

The mixing valve 34 may be connected to the electric water heater 43 via the on-off valve 32. The on-off valve 32 controls the opening and closing of a line that supplies heated water from the electric water heater 43 to the mixing valve 34. The on-off valve 32 is controlled by the control device 10, which will be described later. The on-off valve 32 may be configured as an electromagnetic valve or a pressure valve.

The gas water heater 24 heats the mixed water supplied from the mixing valve 34. The gas water heater 24 controls the temperature of the mixed water to the temperature set in the gas water heater 24 and supplies it as hot water to the hot water tap 36. The gas water heater 24 is installed corresponding to each dwelling unit 2. The gas water heater 24 may be connected to the gas supply source 20 via a gas meter 22. The gas meter 22 may also measure the amount of gas supplied to the gas tap of each dwelling unit 2 without going through the gas water heater 24.

The unheated water supplied from the water supply source 30 may be supplied to the gas water heater 24 without passing through the mixing valve 34. The unheated water supplied from the water supply source 30 may be supplied directly to the water faucet of each dwelling unit 2 without passing through the electric water heater 43 and the gas water heater 24, i.e., without being heated.

The energy supply system 1 may further include a calorimeter 38 between the gas water heater 24 and the hot water tap 36. The calorimeter 38 measures the calorific value of the hot water flowing out from the hot water tap 36. The calorimeter 38 may measure the flow rate and temperature of the hot water flowing out from the hot water tap 36, and calculate the calorific value of the hot water flowing out from the hot water tap 36.

<Control device 10>
As shown in Fig. 1 and Fig. 2, the energy supply system 1 may further include a control device 10. The control device 10 is communicatively connected to a PCS 61 as shown by a dashed line in Fig. 1, and acquires the amount of power generated by the distributed power source 60. The control device 10 is communicatively connected to a collective transaction meter 45 as shown by a dashed line in Fig. 1, and acquires the amount of power received from the power grid 50. The control device 10 may acquire the amount of power flowing back to the power grid 50. The control device 10 is communicatively connected to an electric water heater 43 as shown by a dashed line in Fig. 1, and controls the electric water heater 43. The control device 10 is communicatively connected to an on-off valve 32 and a mixing valve 34 as shown by a dashed line in Fig. 2, and controls the opening and closing of the on-off valve 32 and the mixing ratio of pre-heated water and post-heated water in the mixing valve 34.

The control device 10 may be configured to include at least one processor to provide control and processing power for executing various functions. Each component of the control device 10 may be configured to include at least one processor. A plurality of components among the components of the control device 10 may be realized by a single processor. The entire control device 10 may be realized by a single processor. The processor may execute a program that realizes the various functions of the control device 10. The processor may be realized as a single integrated circuit. An integrated circuit is also called an IC (Integrated Circuit). The processor may be realized as a plurality of communicatively connected integrated circuits and discrete circuits. The processor may be realized based on various other known technologies.

The control device 10 may include a memory unit. The memory unit may include an electromagnetic storage medium such as a magnetic disk, or may include a memory such as a semiconductor memory or a magnetic memory. The memory unit stores various information and programs executed by the control device 10. The memory unit may be configured as a non-transitory readable medium. The memory unit may function as a work memory for the control device 10. At least a part of the memory unit may be configured as a separate entity from the control device 10.

The functions of the control device 10 may be realized by the PCS 61 or by the electric water heater 43. The operation of the electric water heater 43, the opening and closing of the on-off valve 32, and the mixing ratio of the pre-heated water and the heated water in the mixing valve 34 may not be controlled by the control device 10 but may be controlled by each component. In this embodiment, an example configuration in which the control device 10 controls the electric water heater 43, the on-off valve 32, and the mixing valve 34 is described.

(Example of operation for supplying hot water to each consumer facility)
In the configuration illustrated in FIG. 1, the control device 10 of the energy supply system 1 determines whether there is surplus power generated from the distributed power source 60 that is not consumed by the dwelling load 42 and the shared load 41. That is, the control device 10 determines whether the power supplied by the distributed power source 60 exceeds the power demand of the complex consumer facility. When there is surplus power, the control device 10 may operate the electric water heater 43 in the common area 3 using the surplus power. The electric water heater 43 may heat pre-heated water supplied from the water supply source 30 as illustrated in FIG. 2 using the surplus power of the distributed power source 60. The control device 10 may operate the electric water heater 43 regardless of the generation of surplus power. That is, the electric water heater 43 may operate using power including the surplus power.

The electric water heater 43 heats pre-heated water supplied from the water supply source 30 to generate heated water, and stores the heated water in a tank. The electric water heater 43 controls the discharge of the heated water so that the temperature at which the heated water stored in the tank is discharged, or the temperature at which the heated water stored in the tank is mixed with pre-heated water and discharged, is equal to or higher than a first temperature. The electric water heater 43 may set the first temperature to, for example, 35°C.

The mixing valve 34 and the gas water heater 24 are installed corresponding to each dwelling unit 2. In other words, the energy supply system 1 includes a plurality of mixing valves 34 and a plurality of gas water heaters 24. The energy supply system 1 supplies heated water stored in the tank of the electric water heater 43 to the mixing valve 34 through piping branching from the electric water heater 43 to the mixing valve 34 corresponding to each dwelling unit 2. When an on-off valve 32 is connected between the mixing valve 34 and the electric water heater 43, the control device 10 further controls the opening and closing of the on-off valve 32. The control device 10 opens the on-off valve 32 when heated water is supplied from the tank of the electric water heater 43 to the mixing valve 34, and closes the on-off valve 32 when heated water is not supplied to the mixing valve 34.

The mixing valve 34 corresponding to each dwelling unit 2 mixes heated water supplied through a pipe branching off from the electric water heater 43 with unheated water supplied from the water supply source 30, and supplies the mixed water to the gas water heater 24 corresponding to each dwelling unit 2. The temperature of the hot water supplied from the electric water heater 43 is equal to or higher than the first temperature. The control device 10 controls the mixing ratio of the heated water and the unheated water in the mixing valve 34. The control device 10 may set a mixing ratio such that either the heated water or the unheated water is 0%.

The gas water heater 24 is configured to be able to control the temperature of the hot water supplied to the hot water tap 36 of each dwelling unit 2 to a set temperature by heating the mixed water supplied from the mixing valve 34. A user such as a resident of each dwelling unit 2 may set the temperature of the hot water supplied from the gas water heater 24 to the hot water tap 36. The temperature set in the gas water heater 24 may be, for example, 35°C or higher. The temperature set in the gas water heater 24 is also referred to as the user-set temperature. The control device 10 obtains the user-set temperature from the gas water heater 24 and controls the mixing ratio of the pre-heated water and the post-heated water in the mixing valve 34 so that the temperature of the mixed water supplied from the mixing valve 34 to the gas water heater 24 is at least equal to or lower than the user-set temperature.

The control device 10 may also set an upper limit for the temperature of the mixed water supplied from the mixing valve 34 to the gas water heater 24 based on the specifications of the gas water heater 24. The upper limit for the temperature of the mixed water supplied to the gas water heater 24 is also referred to as the acceptable temperature of the gas water heater 24. The acceptable temperature corresponds to the temperature of the mixed water at which the gas water heater 24 may malfunction or be damaged when the mixed water is supplied to the gas water heater 24. For example, the gas water heater 24 is designed to generate hot water by boiling water at room temperature (15°C to 30°C) supplied from the water supply source 30. In this case, for example, if mixed water of 35°C or higher is supplied to the gas water heater 24, the gas water heater 24 may malfunction or be damaged. Therefore, the control device 10 sets the acceptable temperature of the gas water heater 24 so that the temperature of the mixed water supplied to the gas water heater 24 is not higher than the temperature assumed by the gas water heater 24. The control device 10 controls the mixing ratio of the heated water supplied from the electric water heater 43 and the unheated water supplied from the water supply source 30 at the mixing valve 34 so that the temperature of the mixed water supplied to the gas water heater 24 is equal to or lower than the acceptable temperature. The acceptable temperature may be set to, for example, 40°C, or the like, as a temperature at which the gas water heater 24 will not be damaged before the mixed water reaches the gas water heater 24. Also, to ensure a sufficient margin, it may be set to, for example, 35°C, or the like, as a temperature at which at least the gas water heater 24 will not be damaged at the mixing valve 34.

The mixing valve 34 mixes the heated water supplied from the electric water heater 43 and the unheated water supplied from the water supply source 30 so that the temperature of the mixed water supplied to the gas water heater 24 is at least equal to or lower than the user-set temperature. The temperature of the unheated water supplied from the water supply source 30 is lower than the temperature of the heated water supplied from the electric water heater 43. In other words, the temperature of the unheated water supplied from the water supply source 30 is at least lower than the first temperature. For example, the temperature of the unheated water supplied from the water supply source 30 may be lower than the user-set temperature or may be room temperature. In this embodiment, room temperature is a temperature of 15°C or higher and 30°C or lower. The gas water heater 24 heats the mixed water supplied from the mixing valve 34 to raise the temperature to the user-set temperature, and supplies the hot water to the hot water tap 36 of each dwelling unit 2.

As described above, the energy supply system 1 according to this embodiment heats pre-heated water in the electric water heater 43 using surplus power from the distributed power source 60. This promotes self-consumption of the power supplied by the distributed power source 60 in the complex consumer facility. As a result, the energy supply system 1 becomes surplus wiring in the complex consumer facility so that the complex consumer facility meets the ZEH (Zero Emission House) standard or the ZEH-M standard for apartment buildings 4, thereby increasing the self-consumption rate. In other words, the ZEH-M standard is met because the energy supply system 1 is surplus wiring. Furthermore, the self-consumption rate is increased.

Other Embodiments
Hereinafter, a configuration example of the energy supply system 1 according to another embodiment will be described.

<Example of configuration for reducing heat radiation in piping>
In the piping connecting from the tank of electric water heater 43 to mixing valve 34, while the heated water at or above the first temperature is being transported, heat is likely to be dissipated from the heated water to the outside of the piping. The piping connecting from electric water heater 43 to mixing valve 34 may have a heat insulating structure so as to make it difficult for heat to be dissipated to the outside of the piping. In addition, the piping connecting from electric water heater 43 to mixing valve 34 may be as short as possible.

The amount of heat dissipated from the heated water transported through the pipe is reduced as the ratio of the surface area of the pipe to the volume inside the pipe is reduced. The ratio of the surface area of the pipe to the volume inside the pipe can be reduced, for example, by increasing the diameter of the pipe that transports the heated water.

Here, the piping connecting the tank of the electric water heater 43 to the mixing valve 34 corresponding to the gas water heater 24 in each dwelling unit 2 branches at least at one point. In other words, the energy supply system 1 is equipped with piping that branches from the tank of the electric water heater 43 toward the mixing valve 34 corresponding to the gas water heater 24 in each dwelling unit 2. The piping that branches toward the mixing valve 34 is represented by P1 and P2 in FIG. 2. The branching point of the piping is represented by J. P1 corresponds to the portion from the electric water heater 43 to the branching point (J), that is, the portion before branching. P2 corresponds to the portion from the branching point (J) to the mixing valve 34 or the on-off valve 32, that is, the portion after branching.

The diameter of the pipe (P1) before branching is larger than the diameter of the pipe (P2) after branching, based on the difference in the amount of heated water to be transported. The larger the diameter of the pipe, the less heat is released from the heated water. Therefore, by shortening the pipe (P2) from the branch point (J) to the mixing valve 34 or on-off valve 32 as much as possible, the amount of heat released from the entire pipe (P1 and P2) connecting the tank of the electric water heater 43 to the mixing valve 34 or on-off valve 32 corresponding to each dwelling unit 2 can be reduced. Specifically, by making the pipe (P2) shorter than the pipe (P1), the amount of heat released from the entire pipe (P1 and P2) can be reduced.

In addition, the amount of heat dissipation increases as heated water at or above the first temperature flows into the branched pipe (P2). The on-off valve 32 may be installed as close as possible to the branching point (J) of the pipe. Specifically, the length from the branching point (J) of the pipe to the on-off valve 32 is made shorter than the length from the on-off valve 32 to the mixing valve 34. When hot water is not used at the hot water tap 36 of each dwelling unit 2, the control device 10 can reduce the amount of heated water flowing into the branched pipe (P2) by closing the on-off valve 32.

In FIG. 2, the piping connecting the mixing valve 34 to the gas water heater 24 is represented by P3. When the on-off valve 32 is provided, the length from the on-off valve 32 to the mixing valve 34 and the length of the piping (P3) are not particularly limited. When the on-off valve 32 is not provided, the temperature of the mixed water flowing through the piping (P3) is equal to or lower than the acceptable temperature determined based on the specifications of the gas water heater 24 due to the mixing of the pre-heated water in the mixing valve 34. Since the temperature of the mixed water is lower than the temperature of the heated water, the amount of heat released from the mixed water flowing through the piping (P3) after the mixing valve 34 is less than the amount of heat released from the heated water flowing through the piping (P1 or P2) before the mixing valve 34. Therefore, the piping (P3) after the mixing valve 34 may be longer than the piping (P1 and P2) before the mixing valve 34. In this way, the amount of heat released in the entire piping (P1, P2, and P3) can be reduced.

The on-off valve 32 can shut off the outflow of heated water from the tank of the electric water heater 43 by closing. If the state of the on-off valve 32 becomes uncontrollable due to a power outage in the power grid 50 or the like, the on-off valve 32 may be configured to close. In other words, the on-off valve 32 may be configured with a normally closed specification. If the on-off valve 32 becomes uncontrollable in the open state, heated water may flow out of the tank of the electric water heater 43, which may increase the loss of thermal energy. By configuring the on-off valve 32 with a normally closed specification, the risk of thermal energy loss is reduced.

<Equalization of hot water usage in each dwelling unit 2>
In the apartment building 4, when a large amount of hot water flows out from the hot water tap 36 of some of the dwelling units 2, a situation may occur in which the heated water generated by heating the pre-heated water with the electric water heater 43 is consumed in some of the dwelling units 2. In this case, the hot water supplied to the hot water taps 36 of the other dwelling units 2 cannot use the heated water generated by the electric water heater 43, and is generated by heating the pre-heated water supplied from the water supply source 30 as it is with the gas water heater 24. As a result, the gas consumption in the other dwelling units 2 may be greater than the gas consumption in some of the dwelling units 2 that use the heated water generated by heating the pre-heated water with the electric water heater 43. Inequality occurs between the dwelling units 2 in terms of gas consumption. Therefore, the control device 10 may control the mixing valve 34 or the opening/closing valve 32 so that the supply amount of the heated water generated by heating the pre-heated water with the electric water heater 43 to each dwelling unit 2 approaches equality.

Specifically, the control device 10 may control the amount of heated water supplied to the mixing valve 34 corresponding to each dwelling unit 2 based on the amount of heated water stored in the tank of the electric water heater 43. For example, the control device 10 sets a lower mixing ratio of heated water in the mixing valve 34 corresponding to each dwelling unit 2 the greater the amount of heat measured by the calorimeter 38 corresponding to that dwelling unit 2. In this case, the control device 10 acquires calorimeter information from the calorimeter corresponding to each dwelling unit 2. The calorimeter may be disposed in the piping (P3). As a result, the amount of heated water supplied from the electric water heater 43 to each dwelling unit 2 can be made closer to uniform.

<<Control based on power supply information>>
Even if the amount of heated water supplied from electric water heater 43 to each dwelling unit 2 is made as close as possible to equal, if there is excess heated water in electric water heater 43, a situation may arise in which the surplus electricity cannot be consumed by electric water heater 43. Therefore, controller 10 controls the amount of heated water supplied from electric water heater 43 to each dwelling unit 2, on the premise that the heated water in electric water heater 43 will be used up. Specifically, controller 10 controls the amount of heated water supplied to mixing valve 34 corresponding to each dwelling unit 2 based on a prediction of the amount of heated water generated by electric water heater 43.

The control device 10 may acquire information regarding the amount of power supplied by the distributed power source 60 from the PCS 61. Information regarding the amount of power supplied by the distributed power source 60 is also referred to as power supply information. The power supply information may include the amount of power supplied by the distributed power source 60. The power supply information may include a predicted value of the amount of power supplied by the distributed power source 60 for a period beyond the present time (i.e., the future). The power supply information may include a predicted value of surplus power of the distributed power source 60. The surplus power of the distributed power source 60 may be predicted based on seasonal fluctuations. When the distributed power source 60 includes PV 62, the surplus power of the distributed power source 60 may be predicted based on, for example, sunrise time and sunset time. When the distributed power source 60 includes PV 62, the surplus power of the distributed power source 60 may be predicted based on, for example, weather information. The surplus power of the distributed power source 60 is calculated as the difference between the amount of power generated and the amount of power consumed, and may be predicted based on the results of measurements of the amount of power consumed by each dwelling load 42 by the dwelling meter 46 of the resident of each dwelling unit 2 or the results of measurements of the amount of power consumed by the shared load 41 by the shared meter 47.

The control device 10 controls the mixing ratio of heated water to unheated water in the mixing valve 34 based on the power supply information. For example, the control device 10 may increase the ratio of heated water in the mixing valve 34 when the surplus power of the distributed power source 60 is predicted to increase in a specified period from the present time. The control device 10 may decrease the ratio of heated water in the mixing valve 34 when the surplus power of the distributed power source 60 is predicted to decrease in a specified period from the present time.

<<Control based on heat quantity information>>
The control device 10 may acquire information regarding the calorific value of the hot water flowing out from the hot water tap 36 of each dwelling unit 2. Information regarding the calorific value of the hot water flowing out from the hot water tap 36 of each dwelling unit 2 is also referred to as calorific value information. The calorific value of the hot water is represented by the product of the amount of hot water and the temperature of the hot water. The calorific value information may include actual data on the calorific value of the hot water flowing out from the hot water tap 36 of each dwelling unit 2 in the past. The calorific value of the hot water flowing out from the hot water tap 36 of each dwelling unit 2 is measured by a calorimeter 38. The control device 10 may be connected to the calorimeter 38 and acquire the calorific value information from the calorimeter 38. The calorific value information may include a predicted value of the calorific value of the hot water used by the resident of each dwelling unit 2 in a period beyond the present time (i.e., in the future). The calorific value of the hot water used in each dwelling unit 2 may be predicted based on the calorific value measurement results by the calorimeter 38 of each dwelling unit 2, or may be predicted based on seasonal fluctuations.

The control device 10 controls the mixing ratio of heated water to unheated water in the mixing valve 34 based on the heat information. For example, when the control device 10 predicts that the heat amount of the hot water flowing out of the hot water tap 36 of a certain dwelling unit 2 will increase in a specified period from the present time, the control device 10 may lower the ratio of heated water in the mixing valve 34 corresponding to that dwelling unit 2. When the control device 10 predicts that the heat amount of the hot water flowing out of the hot water tap 36 of a certain dwelling unit 2 will decrease in a specified period from the present time, the control device 10 may increase the ratio of heated water in the mixing valve 34 corresponding to that dwelling unit 2.

<<Summary>>
As described above, the control device 10 can control the mixing ratio of the heated water in the mixing valve 34 based on various information such as power generation information or heat quantity information. In this way, the control device 10 can both make the amount of heated water supplied from the electric water heater 43 to each dwelling unit 2 closer to uniform, and make it less likely that a shortage or surplus of heated water will occur in the electric water heater 43.

<Charges for hot water use>
As shown in FIG. 2, the energy supply system 1 may include a calibrated calorimeter 38 connected between the gas water heater 24 and the hot water tap 36. The calorimeter 38 measures the calorific value of the hot water flowing from the hot water tap 36 of each dwelling unit 2. The management entity of the apartment building 4 may bill the residents of each dwelling unit 2 for the use of hot water based on the measurement results of the calorimeter 38. The hot water usage fee corresponds to a combined fee for the use of pre-heated water supplied from the water supply source 30 and the gas fee. This makes billing easier than when the use fee for pre-heated water and the gas fee are billed separately. In addition, if the residents of each dwelling unit 2 do not individually contract for the supply of pre-heated water and gas, but the management entity or owner of the apartment building 4 contracts for them all at once, the fee for pre-heated water supplied from the water supply source 30 and the fee for gas can be easily calculated together based on the measurement results of the calorimeter 38. As a result, convenience is improved for both the party that bills and the party that pays the fee.

In addition, when the shared meter 47 measures the amount of electricity supplied to the electric water heater 43, the management entity of the apartment complex 4 may calculate the electricity fee based on the measurement results of the amount of power consumed by the electric water heater 43 and bill the user for this amount by including it in the fee for hot water use. This simplifies billing.

<Facility owner>
The distributed power source 60 and the electric water heater 43 may be included in the facilities of the apartment building 4. In this case, the owner of the distributed power source 60 and the electric water heater 43 may be the same as the owner of the apartment building 4. In this way, it is easy for the management entity of the apartment building 4 to manage the distributed power source 60 and the electric water heater 43 collectively.

On the other hand, the owner of the electric water heater 43 and the distributed power source 60 may be different from the management entity of the apartment building 4. For example, the electric water heater 43 and the distributed power source 60 may be owned by a gas company that supplies gas to the apartment building 4. The energy supply system 1 according to this embodiment generates heated water by heating pre-heated water in the electric water heater 43 using surplus power from the distributed power source 60, and mixes the pre-heated water in the mixing valve 34 to supply the mixed water to the gas water heater 24. In this case, the amount of gas consumed to heat the mixed water in the gas water heater 24 to generate hot water at a user-set temperature is reduced compared to the amount of gas consumed to heat the pre-heated water to generate hot water at a user-set temperature. When the fee for hot water is charged based on the measurement result of the calorimeter 38, the gas company owns the electric water heater 43 and the distributed power source 60, and the decrease in income due to the decrease in gas consumption at the gas company can be compensated for by the increase in income from the hot water fee allocated to the electric water heater 43.

<Operation timing of gas water heater 24>
If the temperature (second temperature) of the mixed water supplied from the mixing valve 34 to the gas water heater 24 is too low, the amount of gas consumed by the gas water heater 24 increases. Therefore, when a resident of each dwelling unit 2 starts to turn on hot water from the hot water tap 36, the gas water heater 24 does not operate if the temperature (second temperature) of the mixed water supplied from the mixing valve 34 is less than the third temperature, and may wait until the temperature reaches or exceeds the third temperature before starting operation. In this way, the amount of gas consumed by the gas water heater 24 can be reduced.

The control device 10 may control the on-off valve 32 based on the amount of hot water used in each dwelling unit 2. In this way, when the amount of hot water used in the dwelling unit 2 is high, heat loss due to heat radiation from the piping can be reduced by controlling the electric water heater 43 to supply heated water to the gas water heater 24. The control device 10 may control the on-off valve 32 in conjunction with the bath filling function of each dwelling unit 2, for example. The control device 10 may also control the time for which the on-off valve 32 is opened based on the hot water usage history of each dwelling unit 2. The control device 10 may set the third temperature to, for example, 28°C.

The figures illustrating the embodiments of the present disclosure are schematic. The dimensional ratios and other details in the drawings do not necessarily correspond to the actual ones.

Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that a person skilled in the art would be able to make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications or alterations are included in the scope of the present disclosure. For example, the functions included in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined into one or divided.

In this disclosure, descriptions such as "first" and "second" are identifiers for distinguishing the configuration. In the configurations distinguished by descriptions such as "first" and "second" in this disclosure, the numbers in the configurations can be exchanged. For example, the first temperature can exchange the identifiers "first" and "second" with the second temperature. The exchange of identifiers is performed simultaneously. The configurations remain distinguished even after the exchange of identifiers. Identifiers may be deleted. A configuration from which an identifier has been deleted is distinguished by a code. Descriptions of identifiers such as "first" and "second" in this disclosure alone should not be used to interpret the order of the configurations or to justify the existence of identifiers with smaller numbers.

1 Energy supply system 4 Apartment complex (2: dwelling unit, 3: common area)
10 Control device 20 Gas supply source 22 Gas meter 24 Gas water heater 30 Water supply source 31 Water meter 32 Opening/closing valve 34 Mixing valve 36 Hot water tap 38 Calorimeter 40 Load (41: shared load, 42: dwelling load, 43: electric water heater)
45 Centralized transaction meter 46 Residential meter 47 Shared meter 50 Power grid 60 Distributed power source (61: PCS, 62: PV)

Claims (12)

A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Pipes branching from the electric water heater toward each mixing valve;
an on-off valve connected between the branch point of the piping and each of the mixing valves;
Equipped with
Each of the mixing valves supplies mixed water obtained by mixing the heated water and the unheated water to each of the gas water heaters,
The on-off valve is an energy supply system that is closed during a power outage . A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Pipes branching from the electric water heater toward each mixing valve;
an on-off valve connected between the branch point of the piping and each of the mixing valves;
Equipped with
Each of the mixing valves supplies mixed water obtained by mixing the heated water and the unheated water to each of the gas water heaters,
A diameter of a pipe connecting from the electric water heater to a branch point of the pipe is larger than a diameter of a pipe connecting from the branch point of the pipe to the mixing valve,
The portion of the piping from the electric water heater to the branch point of the piping is longer than the portion from the branch point of the piping to the mixing valve,
The on-off valve is an energy supply system that is closed during a power outage . A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Equipped with
Each of the mixing valves supplies mixed water obtained by mixing the heated water and the unheated water to each of the gas water heaters,
The mixing valve is an energy supply system that controls the mixing ratio of the heated water and the unheated water based on information regarding the amount of electricity supplied by the distributed power source . A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Equipped with
Each of the mixing valves is
A mixed water obtained by mixing the heated water and the unheated water is supplied to each of the gas water heaters,
The temperature of the mixed water is controlled to a second temperature that is lower than a temperature set in each of the gas water heaters;
The mixing valve is an energy supply system that controls the mixing ratio of the heated water and the unheated water based on information regarding the amount of electricity supplied by the distributed power source . A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Pipes branching from the electric water heater toward each mixing valve;
an on-off valve connected between the branch point of the piping and each of the mixing valves;
Equipped with
Each of the mixing valves supplies mixed water obtained by mixing the heated water and the unheated water to each of the gas water heaters,
The mixing valve is an energy supply system that controls the mixing ratio of the heated water and the unheated water based on information regarding the amount of electricity supplied by the distributed power source . A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Pipes branching from the electric water heater toward each mixing valve;
an on-off valve connected between the branch point of the piping and each of the mixing valves;
Equipped with
Each of the mixing valves supplies mixed water obtained by mixing the heated water and the unheated water to each of the gas water heaters,
A diameter of a pipe connecting from the electric water heater to a branch point of the pipe is larger than a diameter of a pipe connecting from the branch point of the pipe to the mixing valve,
The portion of the piping from the electric water heater to the branch point of the piping is longer than the portion from the branch point of the piping to the mixing valve,
The mixing valve is an energy supply system that controls the mixing ratio of the heated water and the unheated water based on information regarding the amount of electricity supplied by the distributed power source . A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Pipes branching from the electric water heater toward each mixing valve;
an on-off valve connected between the branch point of the piping and each of the mixing valves;
Equipped with
Each of the mixing valves supplies mixed water obtained by mixing the heated water and the unheated water to each of the gas water heaters,
The on-off valve is closed during a power outage,
The mixing valve is an energy supply system that controls the mixing ratio of the heated water and the unheated water based on information regarding the amount of electricity supplied by the distributed power source . A plurality of gas water heaters configured to be capable of controlling the temperature of hot water supplied to each of a plurality of consumer facilities in a complex consumer facility;
an electric water heater that generates heated water having a first temperature or higher by heating pre-heated water using electricity including surplus electricity from a distributed power source that supplies electricity to each of the consumer facilities, and supplies the heated water to each of the gas water heaters ;
a plurality of mixing valves connected to each of the gas water heaters between the electric water heater and the plurality of gas water heaters;
Equipped with
Each of the mixing valves supplies mixed water obtained by mixing the heated water and the unheated water to each of the gas water heaters,
A pipe connecting the electric water heater to the mixing valve is shorter than a pipe connecting the mixing valve to the gas water heater,
The mixing valve is an energy supply system that controls the mixing ratio of the heated water and the unheated water based on information regarding the amount of electricity supplied by the distributed power source . An energy supply system as described in any one of claims 1 to 8, wherein each of the gas water heaters does not operate when the temperature of the mixed water is below a third temperature, and waits until the temperature of the mixed water becomes equal to or higher than the third temperature before operating. The energy supply system according to any one of claims 1 to 9, further comprising a calorimeter that measures the calorific value of the hot water supplied by each of the gas water heaters to each of the consumer facilities. The complex consumer facility includes an apartment building,
Each of the consumer facilities includes each of the dwelling units and common areas of the housing complex,
The common area has a common meter,
The energy supply system according to claim 1 , wherein the electric water heater is connected to the shared meter. The energy supply system according to any one of claims 1 to 11, wherein the owner of the electric water heater and the distributed power source is different from the management entity of the complex consumer facility.

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