Water heater

Abstract

To solve the problem in which, when a positive DR request is received for increasing power consumption of a boiling device in a first period further than usual, and during the night time right before the first period, for example, a water amount which is projected to be consumed before the next hot water filling is boiled, the power consumption of the boiling device in the first period cannot be increased sufficiently.SOLUTION: A boiling device 1 has a control part 190. The control part 190 controls a boiling operation for heating hot water in a hot water storage tank. The control part 190 receives a positive DR request. The control part 190 boils a second water amount by a night time boiling operation during the night time right before a first period. The control part 190 boils a first water amount by a day time boiling operation in the first period. The second water amount is a water amount equal to or greater than the water amount that is predicted to be consumed from the end of a second boiling operation to the elapse of the first period.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] It relates to a water supply device.

Background Art

[0002] As shown in Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2021-18021), it is known to increase the power consumption of the boiling device in the first period in response to a demand response request from an aggregator more than usual.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In Patent Document 1, there is a possibility that the power consumption of the boiling device in the first period cannot be sufficiently increased because the amount of water predicted to be consumed by the next water pouring is boiled up during the night immediately before the first period.

Means for Solving the Problems

[0004] The water supply device of the first aspect includes a tank and a boiling device. The boiling device has a control unit. The control unit controls a boiling operation for heating the hot water in the tank. The control unit receives a first request for demand response. The first request is a request to increase the power consumption of the boiling device in the first period more than usual. The control unit boils up a second amount of water by a second boiling operation during the night immediately before the first period. The control unit boils up a first amount of water by a first boiling operation during the first period. The second amount of water is an amount of water that is more than the amount of water predicted to be consumed from the end of the second boiling operation until the elapse of the first period.

[0005] In the water heater of the first aspect, when the control unit receives the first demand response request to increase the power consumption of the boiling device in the first period more than usual, it boils the second water volume by the second boiling operation at night immediately before the first period. The second water volume is greater than or equal to the water volume whose consumption is predicted from the end of the second boiling operation to the elapse of the first period. As a result, the water heater boils the water volume whose consumption is predicted from the end of the second boiling operation to the elapse of the first period at night immediately before the first period, so that the power consumption of the boiling device in the first period can be sufficiently increased.

[0006] The water heater of the second aspect is the water heater of the first aspect, and the second water volume is less than the water volume obtained by subtracting the first water volume from the capacity of the tank.

[0007] The water heater of the third aspect is the water heater of the first or second aspect, and the first water volume is the water volume that can be boiled by the power consumption required by the first request.

[0008] The water heater of the fourth aspect is the water heater of any one of the first to third aspects, and the first water volume is the water volume that can be boiled by continuously performing the first boiling operation during the first period.

[0009] The water heater of the fifth aspect is the water heater of any one of the first to fourth aspects. After the first period, when the consumption of a third water volume of a predetermined amount or more is predicted, the control unit further boils the third water volume at night.

[0010] With such a configuration, the water heater of the fifth aspect can continuously supply hot water at the temperature desired by the user to the user.

[0011] The water heater of the sixth aspect is the water heater of any one of the first to fifth aspects, and the heating capacity of the first boiling operation is higher than the heating capacity of the second boiling operation.

[0012] The water supply device from the sixth perspective can increase the power consumption of the boiling device during the first period more than usual with such a configuration.

[0013] The water supply device from the seventh perspective is the water supply device from the sixth perspective, and the boiling completion temperature at the end of the first boiling operation is higher than the boiling completion temperature at the end of the second boiling operation. The boiling completion temperature is the temperature of the water inlet pipe connected to the water heat exchanger.

[0014] The water supply device from the seventh perspective can increase the power consumption of the boiling device during the first period more than usual with such a configuration.

[0015] The water supply device from the eighth perspective is any one of the water supply devices from the first to the seventh perspectives. When the first request is cancelled before the start of the first period after the night has passed, the control unit boils the first water volume during the day after the cancellation of the first request.

[0016] The water supply device from the eighth perspective can suppress the power consumption and boil the first water volume by boiling the first water volume during the day when the outside air temperature is relatively high with such a configuration.

[0017] The water supply device from the ninth perspective is any one of the water supply devices from the first to the eighth perspectives. When the first request is cancelled before the start of the first period after the night has passed, the control unit boils the first water volume by the third boiling operation after the cancellation of the first request. The third boiling operation is a boiling operation with a lower heating capacity than the second boiling operation.

[0018] The water supply device from the ninth perspective can suppress the power consumption and boil the first water volume with such a configuration.

[0019] The water supply device from the tenth perspective is any one of the water supply devices from the first to the ninth perspectives. When the first request is cancelled at night, the control unit further boils the first water volume at night.

[0020] Generally, since the unit price of electricity in a commercial power system is lower at night than during the day, the water heater from the tenth perspective can raise the first water volume while suppressing costs.

[0021] The water heater from the eleventh perspective is any one of the water heaters from the first to the tenth perspective, and the control unit further receives a second request for demand response. The second request is a request to reduce the power consumption of the boiling device during the third period compared to normal. The first water volume is not less than the water volume predicted to be consumed during the third period.

[0022] With such a configuration, the water heater from the eleventh perspective can increase the power consumption of the boiling device during the first period and decrease the power consumption of the boiling device during the third period.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0024] (1) Overall Configuration The water heater 100 adjusts the power consumption of the commercial power system in response to a request for demand response (hereinafter, may be referred to as a DR request).

[0025] Demand response is that a user (consumer) receiving power supply from a commercial power system adjusts the power consumption of the commercial power system in response to a request from an aggregator 90 such as an electric power company that supplies power to the commercial power system. The aggregator 90 pays the user a reward as the consideration for demand response according to the adjustment amount of the power consumption of the commercial power system.

[0026] FIG. 1 is a schematic configuration diagram of a hot water supply apparatus 100. As shown in FIG. 1, the hot water supply apparatus 100 mainly includes a heat pump unit 110, a hot water storage unit 120, a remote controller 130, and a control unit 190. A hot water supply section 140, a bathtub 150, and a stop valve 160 are connected to the hot water storage unit 120.

[0027] The heat pump unit 110 heats the hot water supplied from the hot water storage unit 120 and supplies the heated hot water to the hot water storage unit 120. The hot water storage unit 120 stores the heated hot water supplied from the heat pump unit 110, mixes the stored hot water with the water supplied from the stop valve 160, and supplies the mixture to the hot water supply section 140 and the bathtub 150. The heat pump unit 110 and the hot water storage unit 120 constitute a boiling-up device 1 that boils up the hot water in a hot water storage tank 21 included in the hot water storage unit 120. The hot water supply section 140 is, for example, a faucet and a shower. The stop valve 160 is connected to an external water supply source such as a water supply. The stop valve 160 is operated to supply water to the hot water storage unit 120.

[0028] Here, the "hot water" means at least one of hot water and water. Therefore, both the water before being heated by the heat pump unit 110 and the water after being heated by the heat pump unit 110 are referred to as hot water.

[0029] (2) Detailed configuration (2-1) Heat pump unit The heat pump unit 110 mainly includes a compressor 11, a water heat exchanger 12, an expansion valve 13, and an air heat exchanger 14. The compressor 11, the water heat exchanger 12, the expansion valve 13, and the air heat exchanger 14 are connected in a loop by refrigerant pipes to form a heat pump cycle. The discharge side of the compressor 11 is connected to the water heat exchanger 12, and the suction side of the compressor 11 is connected to the air heat exchanger 14. One end of the expansion valve 13 is connected to the water heat exchanger 12, and the other end of the expansion valve 13 is connected to the air heat exchanger 14. Further, the heat pump unit 110 has a first control device 10.

[0030] The refrigerant circulating in the heat pump cycle has a critical temperature higher than the temperature of the heated hot water supplied from the heat pump unit 110 to the hot water storage unit 120. The critical temperature of the refrigerant is preferably 10°C or higher than the temperature of the heated hot water. The refrigerant is, for example, R32 (critical temperature 78.1°C), HFO-1234yf (critical temperature 95.0°C), and R410 (critical temperature 71.4°C).

[0031] The compressor 11 has a compression mechanism that compresses the refrigerant by driving the motor 11a. The refrigerant compressed by the compressor 11 is sent to the water heat exchanger 12. The capacity of the heat pump unit 110 can be adjusted by controlling the operating frequency of the motor 11a.

[0032] The water heat exchanger 12 performs heat exchange between the high-temperature refrigerant compressed by the compressor 11 and the hot water supplied from the hot water storage unit 120 to heat the hot water. The water heat exchanger 12 is, for example, a double-tube heat exchanger composed of an outer tube and an inner tube inserted inside the outer tube. The water heat exchanger 12 may also be a plate-type heat exchanger or the like. The capacity of the heat pump unit 110 is, for example, the amount of heat that the water heat exchanger 12 imparts to the hot water supplied from the hot water storage unit 120 per unit time.

[0033] The expansion valve 13 reduces the pressure of the refrigerant that has passed through the water heat exchanger 12 and undergone heat exchange. The expansion valve 13 is, for example, an electric expansion valve. The expansion valve 13 may also be a capillary tube or the like.

[0034] The air heat exchanger 14 performs heat exchange between the refrigerant that has passed through the expansion valve 13 and been depressurized and the outside air to heat the refrigerant. For example, the outside air is supplied to the air heat exchanger 14 by an outside air fan. The refrigerant that has undergone heat exchange through the air heat exchanger 14 is sent to the compressor 11.

[0035] (2-2) Hot water storage unit The hot water storage unit 120 mainly includes a hot water storage tank 21 (tank), a first drain valve 22, a water inlet valve 23, a boiling-up pump 24, a bypass valve 25, a boiling-up valve 26, a first mixing valve 27, a second mixing valve 28, a pressure reducing valve 29, a first flow sensor 30, a hot water supply solenoid valve 31, a second drain valve 32, a second flow sensor 33, a post-combustion pump 34, and a post-combustion heat exchanger 35. These elements are connected by pipes L1-L19 through which hot and cold water flows. Temperature sensors T1-T11 are provided in the hot water storage tank 21 and pipes L10, L13, L14, L16. The hot water storage unit 120 also has a second control device 20.

[0036] The hot water storage tank 21 stores hot and cold water. Six temperature sensors T1-T6 are provided in the hot water storage tank 21. The six temperature sensors T1-T6 are composed of a first hot water volume temperature sensor T1, a second hot water volume temperature sensor T2, a third hot water volume temperature sensor T3, a fourth hot water volume temperature sensor T4, a fifth hot water volume temperature sensor T5, and an upper temperature sensor T6. The upper temperature sensor T6 is provided near the upper end surface of the hot water storage tank 21. The first-fifth hot water volume temperature sensors T1-T5 are provided on the side surface of the hot water storage tank 21 at intervals from the upper side to the lower side.

[0037] Since the density of water changes according to temperature, the hot and cold water stored in the hot water storage tank 21 forms a layer with a high temperature on the upper side and a low temperature on the lower side. Therefore, based on the output signals of the temperature sensors T1-T6, by detecting the temperature distribution of the hot and cold water in the hot water storage tank 21 in the vertical direction, the amount of hot and cold water (hot water storage amount) in the hot water storage tank 21 can be obtained. The number of temperature sensors provided in the hot water storage tank 21 to obtain the hot water storage amount of the hot water storage tank 21 may be any number other than 6.

[0038] One end of the water inlet pipe L1 is connected to the lower end surface of the hot water storage tank 21, and the other end of the water inlet pipe L1 is connected to the inlet side of the water heat exchanger 12 of the heat pump unit 110. From the hot water storage tank 21 towards the water heat exchanger 12, a water inlet valve 23, a boiling pump 24, and a bypass valve 25 are provided in the water inlet pipe L1. The water inlet valve 23 and the bypass valve 25 are electric three-way valves. Between the bypass valve 25 and the water heat exchanger 12, a boiling completion temperature sensor T11 is provided in the water inlet pipe L1. The boiling completion temperature sensor T11 detects the temperature of the hot water flowing in the water inlet pipe L1 after the boiling operation is completed.

[0039] The first drain pipe L2 branches from the water inlet pipe L1 between the hot water storage tank 21 and the water inlet valve 23. A first drain valve 22 is provided in the first drain pipe L2. The first drain pipe L2 is connected to a drain pipe outside the hot water storage unit 120. The first drain valve 22 is operated, for example, to discharge the hot water in the hot water storage tank 21 to the outside.

[0040] One end of the hot water outlet pipe L3 is connected to the outlet side of the water heat exchanger 12 of the heat pump unit 110, and the other end of the hot water outlet pipe L3 is connected to the boiling valve 26. The boiling valve 26 is an electric three-way valve.

[0041] One end of the first return pipe L4 is connected to the boiling valve 26, and the other end of the first return pipe L4 is connected to the upper end surface of the hot water storage tank 21.

[0042] One end of the second return pipe L5 is connected to the boiling valve 26, and the other end of the second return pipe L5 is connected to the lower end surface of the hot water storage tank 21.

[0043] One end of the bypass pipe L6 is connected to the bypass valve 25, and the other end of the bypass pipe L6 is connected to the hot water outlet pipe L3.

[0044] One end of the first boiling pipe L7 is connected to the upper end surface of the hot water storage tank 21, and the other end of the first boiling pipe L7 is connected to the first mixing valve 27. The first mixing valve 27 is an electric three-way valve.

[0045] One end of the second boiling-up pipe L8 is connected to the upper end surface of the hot water storage tank 21, and the other end of the second boiling-up pipe L8 is connected to the second mixing valve 28. The second mixing valve 28 is an electric three-way valve.

[0046] One end of the tank water supply pipe L9 is connected to the stop valve 160 outside the hot water storage unit 120, and the other end of the tank water supply pipe L9 is connected to the lower end surface of the hot water storage tank 21. A pressure reducing valve 29 is provided in the tank water supply pipe L9. The pressure reducing valve 29 is operated to adjust the pressure (water supply pressure) of the water supplied to the hot water storage unit 120 via the stop valve 160.

[0047] The branched water supply pipe L10 branches from the tank water supply pipe L9 between the pressure reducing valve 29 and the hot water storage tank 21. The branched water supply pipe L10 branches into a first mixed water pipe L11 and a second mixed water pipe L12. The first mixed water pipe L11 is connected to the first mixing valve 27. The second mixed water pipe L12 is connected to the second mixing valve 28. A mixed water temperature sensor T7 is provided in the branched water supply pipe L10. The mixed water temperature sensor T7 detects the temperature of the hot water flowing in the branched water supply pipe L10.

[0048] One end of the first hot water supply pipe L13 is connected to the first mixing valve 27, and the other end of the first hot water supply pipe L13 is connected to the hot water supply unit 140. A first flow rate sensor 30 is provided in the first hot water supply pipe L13. The first flow rate sensor 30 detects the flow rate of the hot water in the first hot water supply pipe L13. A first hot water supply temperature sensor T8 is provided in the first hot water supply pipe L13 between the first flow rate sensor 30 and the hot water supply unit 140. The first hot water supply temperature sensor T8 detects the temperature of the hot water flowing in the first hot water supply pipe L13.

[0049] One end of the second hot water supply pipe L14 is connected to the second mixing valve 28, and the other end of the second hot water supply pipe L14 is connected to the bathtub 150. In the second hot water supply pipe L14 from the second mixing valve 28 toward the bathtub 150, a hot water filling solenoid valve 31 and a second flow rate sensor 33 are provided. The second flow rate sensor 33 detects the flow rate of the hot water in the second hot water supply pipe L14.

[0050] The second drain pipe L15 branches from the second hot water supply pipe L14 between the hot water supply solenoid valve 31 and the second flow sensor 33. A second drain valve 32 is provided in the second drain pipe L15. The second drain pipe L15 is connected to a drain pipe outside the hot water storage unit 120. The second drain valve 32 is operated, for example, to discharge a part of the hot water flowing through the second hot water supply pipe L14 to the outside in order to adjust the amount of hot water flowing through the second hot water supply pipe L14.

[0051] One end of the first bathtub return pipe L16 is connected to the bathtub 150, and the other end of the first bathtub return pipe L16 is connected to the inlet side of the afterburner heat exchanger 35. An afterburner pump 34 is provided in the first bathtub return pipe L16. A bathtub return temperature sensor T10 is provided in the first bathtub return pipe L16 between the bathtub 150 and the afterburner pump 34. The bathtub return temperature sensor T10 detects the temperature of the hot water flowing in the first bathtub return pipe L16.

[0052] One end of the second bathtub return pipe L17 is connected to the outlet side of the afterburner heat exchanger 35, and the other end of the second bathtub return pipe L17 is connected to the second hot water supply pipe L14 between the second flow sensor 33 and the bathtub 150. A second hot water supply temperature sensor T9 is provided in the second hot water supply pipe L14 between the connection point of the second bathtub return pipe L17 and the second hot water supply pipe L14 and the bathtub 150. The second hot water supply temperature sensor T9 detects the temperature of the hot water flowing in the second hot water supply pipe L14.

[0053] The first afterburner pipe L18 branches from the second hot water supply pipe L14 between the second mixing valve 28 and the hot water supply solenoid valve 31. The first afterburner pipe L18 is connected to the inlet side of the afterburner heat exchanger 35.

[0054] One end of the second afterburner pipe L19 is connected to the outlet side of the afterburner heat exchanger 35, and the other end of the second afterburner pipe L19 is connected to the water inlet valve 23.

[0055] (2-3) Remote Controller The remote controller 130 is a user interface for controlling the water heater 100. The remote controller 130 is installed, for example, in the kitchen and the bathroom. As shown in FIG. 2, the remote controller 130 is connected to the first control device 10 and the second control device 20 so as to be capable of two-way data communication by wireless communication or wired communication. Signals for instructing the operation of the water heater 100 are input from the remote controller 130 to the first control device 10 and the second control device 20 by wireless communication or wired communication. In addition to the remote controller 130, a portable information terminal such as a smartphone 91 may be used as a user interface of the water heater 100.

[0056] The remote controller 130 has a display unit 130a and an operation unit 130b. The display unit 130a is, for example, a liquid crystal display or an organic EL display.

[0057] The display unit 130a displays information regarding the state of the water heater 100 and information regarding the settings of the water heater 100. The display unit 130a displays, for example, the set value of the temperature of the hot water supplied to the hot water supply unit 140 and the bathtub 150 (hot water supply temperature) and the amount of stored hot water in the hot water storage tank 21.

[0058] The operation unit 130b includes buttons, dials, keys, etc. for the user of the water heater 100 to operate. The user of the water heater 100 operates the operation unit 130b to input information such as the set value of the hot water supply temperature. The display unit 130a may be a touch screen that also has the function of the operation unit 130b.

[0059] The remote controller 130 may further have a speaker, a microphone, etc. In this case, the remote controller 130 may notify the information displayed on the display unit 130a by the speaker and acquire the information input by the operation unit 130b via the microphone.

[0060] (2-4) Control Unit The control unit 190 mainly consists of the first control device 10 of the heat pump unit 110 and the second control device 20 of the hot water storage unit 120. The first control device 10 and the second control device 20 typically consist of a microcomputer equipped with a control arithmetic unit and a storage device, and an input / output circuit. The control arithmetic unit is a processor such as a CPU or a GPU. The control arithmetic unit reads out the control program stored in the storage device and controls the operation of the water supply device 100 according to the control program. The control arithmetic unit can write the calculation result into the storage device or read out the information stored in the storage device according to the control program.

[0061] However, the configuration of the control unit 190 is not limited to the above. For example, the first control device 10 and the second control device 20 may communicate with each other to perform cooperative operations. Also, instead of including the first control device 10 and the second control device 20, the water supply device 100 may have the functions of both the first control device 10 and the second control device 20, and be equipped with a device provided in either the heat pump unit 110 or the hot water storage unit 120. Such a device may be installed outside the water supply device 100 and connected to the heat pump unit 110 and the hot water storage unit 120 via a network.

[0062] Figure 2 is a functional block diagram of the water supply device 100. As shown in Figure 2, the control unit 190 controls the compressor 11, the expansion valve 13, the water inlet valve 23, the boiling pump 24, the bypass valve 25, the boiling valve 26, the first mixing valve 27, the second mixing valve 28, the hot water discharge solenoid valve 31, the afterburning pump 34, etc. based on the signals from the temperature sensors T1 - T10, the first flow sensor 30, and the second flow sensor 33. Also, the control unit 190 is communicably connected to the aggregator 90 via the network NW.

[0063] The control unit 190 mainly performs boiling operation, hot water supply operation, hot water discharge operation, and afterburning operation. Also, the control unit 190 has, as functional blocks, a receiving unit 191 and a DR control unit 192.

[0064] (2-4-1) Boiling operation The boiling operation is an operation in which the heat pump unit 110 heats the hot water in the hot water storage tank 21. In the boiling operation, by driving the boiling pump 24, the hot water in the hot water storage tank 21 is guided to the water heat exchanger 12 through the water inlet pipe L1 and heated. The hot water heated in the water heat exchanger 12 is returned into the hot water storage tank 21 through the hot water outlet pipe L3, the first return pipe L4, and the second return pipe L5. Thus, in the boiling operation, while circulating the hot water in the hot water storage tank 21 through the water inlet pipe L1, the hot water outlet pipe L3, the first return pipe L4, and the second return pipe L5, it is heated in the water heat exchanger 12.

[0065] The control unit 190 performs the boiling operation by controlling the compressor 11, the expansion valve 13, the water inlet valve 23, the boiling pump 24, the bypass valve 25, and the boiling valve 26. The control unit 190 controls the operating frequency of the motor 11a of the compressor 11 and the opening degree of the expansion valve 13 to adjust the capacity of the heat pump unit 110 and the temperature of the hot water (hot water outlet temperature) heated in the water heat exchanger 12, etc. The control unit 190 controls the rotation speed of the boiling pump 24 to adjust the hot water outlet temperature, the hot water storage amount in the hot water storage tank 21, and the flow rate of the hot water supplied to the hot water storage tank 21 (storage flow rate), etc.

[0066] In the normal boiling operation of circulating the hot water in the hot water storage tank 21, the control unit 190 controls the water inlet valve 23 so that the water inlet pipe L1 does not communicate with the second reheating pipe L19, and controls the bypass valve 25 so that the water inlet pipe L1 does not communicate with the bypass pipe L6. The control unit 190 controls the water inlet valve 23 when performing the reheating operation as described later.

[0067] The control unit 190 can control the bypass valve 25 to switch between a state where the hot water flowing through the water inlet pipe L1 passes through the water heat exchanger 12 and is supplied to the hot water outlet pipe L3, and a state where the hot water flowing through the water inlet pipe L1 bypasses the water heat exchanger 12 and is supplied to the hot water outlet pipe L3. In the state of bypassing the water heat exchanger 12, the water inlet pipe L1 communicates with the bypass pipe L6, and the hot water in the hot water storage tank 21 circulates without being heated in the water heat exchanger 12.

[0068] The control unit 190 can control the boiling-up valve 26 to switch between a state in which hot water is supplied from the water heat exchanger 12 to the hot water storage tank 21 via the first return pipe L4 and a state in which hot water is supplied from the water heat exchanger 12 to the hot water storage tank 21 via the second return pipe L5.

[0069] The control unit 190 may obtain the hot water outlet temperature, the stored hot water amount, and the storage flow rate based on the operating frequency of the motor 11a of the compressor 11, the opening degree of the expansion valve 13, the rotation speed of the boiling-up pump 24, the states of the bypass valve 25 and the boiling-up valve 26, and the output signals of the temperature sensors T1 - T6 of the hot water storage tank 21.

[0070] The control unit 190 may perform feedback control on the operating frequency of the motor 11a of the compressor 11, the opening degree of the expansion valve 13, the rotation speed of the boiling-up pump 24, and the states of the bypass valve 25 and the boiling-up valve 26 so that the hot water outlet temperature, the stored hot water amount, and the storage flow rate reach predetermined target values.

[0071] The control unit 190 uses the power of the commercial power system to execute a nighttime boiling-up operation (second boiling-up operation) and a daytime boiling-up operation (first boiling-up operation). The nighttime boiling-up operation is a boiling-up operation performed during at least a part of the nighttime time period. The daytime boiling-up operation is a boiling-up operation performed during at least a part of the daytime time period. The daytime time period is the time period other than the nighttime time period. The nighttime time period and the daytime time period may be set by the user of the water supply device 100 operating the remote controller 130. In this embodiment, it is assumed that the nighttime time period is the time period from 23:00 to 7:00 of the next day, and the daytime time period is the time period from 7:00 to 23:00.

[0072] (2 - 4 - 2) Hot water supply operation The hot water supply operation is an operation of discharging the hot water in the hot water storage tank 21 from the hot water supply unit 140. In the hot water supply operation, when the hot water supply unit 140 is a faucet, by opening the faucet, water from the outside is supplied into the hot water storage tank 21 from the lower part of the hot water storage tank 21 through the tank water supply pipe L9 by the water supply pressure. As a result, the high-temperature hot water stored in the hot water storage tank 21 is pushed out from the upper part of the hot water storage tank 21 through the first boiling-up pipe L7.

[0073] Then, the high-temperature hot water is supplied from the hot water storage tank 21 to the first mixing valve 27 through the first boiling-up pipe L7, and water from the outside is supplied to the first mixing valve 27 through the tank water supply pipe L9, the branch water supply pipe L10, and the first mixed water pipe L11. In the first mixing valve 27, the high-temperature hot water from the first boiling-up pipe L7 is mixed with the water from the first mixed water pipe L11. The mixed hot water is discharged from the hot water supply unit 140 through the first hot water supply pipe L13.

[0074] When the hot water supply unit 140 is opened by the user and the first flow rate sensor 30 detects an increase in the flow rate of the hot water in the first hot water supply pipe L13, the control unit 190 starts the hot water supply operation. During the execution of the hot water supply operation, the control unit 190 controls the first mixing valve 27 according to the temperature of the hot water discharged from the hot water supply unit 140. The control unit 190 may use the temperature detected by the first hot water supply temperature sensor T8 as the temperature of the hot water discharged from the hot water supply unit 140.

[0075] The control unit 190 may perform feedback control on the mixing ratio of the high-temperature hot water and water in the first mixing valve 27 so that the temperature of the hot water discharged from the hot water supply unit 140 reaches a predetermined target value based on the output signals of the mixed water temperature sensor T7 and the first hot water supply temperature sensor T8, etc.

[0076] (2-4-3) Hot water draining operation The hot water supply operation is an operation of supplying the hot water in the hot water storage tank 21 into the bathtub 150. In the hot water supply operation, by opening the hot water supply solenoid valve 31, water from the outside is supplied into the hot water storage tank 21 from the lower part of the hot water storage tank 21 through the tank water supply pipe L9 by the water supply pressure. As a result, the high-temperature hot water stored in the hot water storage tank 21 is pushed out from the upper part of the hot water storage tank 21 through the second boiling-up pipe L8.

[0077] Then, the high-temperature hot water is supplied from the hot water storage tank 21 to the second mixing valve 28 through the second boiling-up pipe L8, and water from the outside is supplied to the second mixing valve 28 through the tank water supply pipe L9, the branch water supply pipe L10, and the second mixed water pipe L12. In the second mixing valve 28, the high-temperature hot water from the second boiling-up pipe L8 is mixed with the water from the second mixed water pipe L12. The mixed hot water is supplied into the bathtub 150 through the second hot water supply pipe L14.

[0078] When the control unit 190 receives a start signal for the hot water supply operation by the operation of the remote controller 130 by the user, it opens the hot water supply solenoid valve 31. As a result, when the second flow rate sensor 33 detects an increase in the flow rate of the hot water in the second hot water supply pipe L14, the hot water supply operation is started. During the execution of the hot water supply operation, the control unit 190 controls the second mixing valve 28 according to the temperature of the hot water supplied into the bathtub 150. The control unit 190 may use the temperature detected by the second hot water supply temperature sensor T9 as the temperature of the hot water supplied into the bathtub 150.

[0079] The control unit 190 may perform feedback control on the mixing ratio of the high-temperature hot water and water in the second mixing valve 28 so that the temperature of the hot water supplied into the bathtub 150 reaches a predetermined target value based on the output signals of the mixed water temperature sensor T7 and the second hot water supply temperature sensor T9, etc.

[0080] During the hot water filling operation, the control unit 190 may also close the hot water filling solenoid valve 31 to end the hot water filling operation when it receives an end signal for the hot water filling operation through the operation of the remote controller 130 by the user, or when the water level in the bathtub 150 detected by a water level sensor (not shown) provided in the bathtub 150 reaches a predetermined target value.

[0081] (2-4-4) Afterburning operation The afterburning operation is an operation in which the hot water in the bathtub 150 is heated in the afterburning heat exchanger 35 and then returned to the bathtub 150. In the afterburning operation, by driving the afterburning pump 34, a part of the hot water in the bathtub 150 is guided to the afterburning heat exchanger 35 through the first bathtub return pipe L16 and heated. The hot water heated in the afterburning heat exchanger 35 is returned to the bathtub 150 through the second bathtub return pipe L17 and the second hot water supply pipe L14. Thus, in the afterburning operation, the hot water in the bathtub 150 is circulated through the first bathtub return pipe L16, the second bathtub return pipe L17, and the second hot water supply pipe L14 while being heated in the afterburning heat exchanger 35.

[0082] The afterburning heat exchanger 35 performs heat exchange between the high-temperature hot water supplied from the hot water storage tank 21 through the second hot water supply pipe L14 and the first afterburning pipe L18, and the low-temperature hot water supplied from the bathtub 150 through the first bathtub return pipe L16. Thereby, the afterburning heat exchanger 35 heats the hot water supplied from the bathtub 150 through the first bathtub return pipe L16. The high-temperature hot water supplied to the afterburning heat exchanger 35 through the first afterburning pipe L18 is supplied to the water inlet pipe L1 through the second afterburning pipe L19 and the water inlet valve 23 after heat exchange. The afterburning heat exchanger 35 may be, for example, a counter-flow type heat exchanger in which the high-temperature hot water and the low-temperature hot water flow in opposite directions for heat exchange.

[0083] When the control unit 190 receives a start signal for post-combustion operation through the operation of the remote controller 130 by the user, it controls the water inlet valve 23 to communicate the water inlet pipe L1 and the second post-combustion pipe L19, drives the boiling pump 24 and the post-combustion pump 34, and starts the post-combustion operation. During the execution of the post-combustion operation, the control unit 190 controls the rotation speeds of the boiling pump 24 and the post-combustion pump 34 according to the temperature of the hot water in the bathtub 150 and the temperature of the hot water returned from the post-combustion heat exchanger 35 into the bathtub 150. The control unit 190 may use the temperature detected by the bathtub return temperature sensor T10 as the temperature of the hot water in the bathtub 150, and use the temperature detected by the second hot water supply temperature sensor T9 as the temperature of the hot water returned from the post-combustion heat exchanger 35 into the bathtub 150.

[0084] Based on the output signals of the second hot water supply temperature sensor T9 and the bathtub return temperature sensor T10, etc., the control unit 190 may perform feedback control on the rotation speeds of the boiling pump 24 and the post-combustion pump 34 so that the temperature of the hot water in the bathtub 150 reaches a predetermined target value.

[0085] Also, during the execution of the post-combustion operation, when the control unit 190 receives an end signal for the post-combustion operation through the operation of the remote controller 130 by the user, or when the temperature of the hot water in the bathtub 150 reaches a predetermined target value, it controls the water inlet valve 23 so that the second post-combustion pipe L19 does not communicate with the water inlet pipe L1, stops the post-combustion pump 34, and may end the post-combustion operation.

[0086] (2-4-5) Receiver The receiver 191 receives a DR request from the aggregator 90 via the network NW. The DR request has a first request and a second request.

[0087] The first request is a request to increase the power consumption of the boiling device 1 in the first period more than usual. The aggregator 90 makes the first request to the control unit 190 before the arrival of the first period when it is predicted that the power of the commercial power system will be surplus. Hereinafter, the first request may be described as an up-DR request.

[0088] The second request is a request to reduce the power consumption of the boiling device 1 during the third period. Before the arrival of the third period, which is predicted to be a period when the power of the commercial power system is in short supply, the aggregator 90 makes the second request to the control unit 190. Hereinafter, the second request may be referred to as a down DR request.

[0089] In the present embodiment, the case where the receiving unit 191 receives the up DR request immediately before the nighttime period of the boiling operation will be described. Assume that the first period is a part of the daytime period (for example, from 11:00 to 14:00) following the nighttime period.

[0090] (2-4-6)DR control unit The DR control unit 192 controls the boiling operation according to the DR request.

[0091] When the DR control unit 192 receives the up DR request from the receiving unit 191, it boils up the second water volume W2 by the nighttime boiling operation during the nighttime period immediately before the first period. Further, the DR control unit 192 boils up the first water volume W1 by the daytime boiling operation during the first period. Here, the "nighttime period immediately before the first period" can also be expressed as the nighttime period of the day before the day when the first period is set.

[0092] FIG. 3 is a diagram for explaining the first water volume W1 and the second water volume W2. The hot water in the hot water storage tank 21 is boiled up from the upper part of the hot water storage tank 21 toward the lower part of the hot water storage tank 21. As shown in the left diagram of FIG. 3, the second water volume W2 is the amount of hot water above the broken line G1. The first water volume W1 is the amount of hot water below the broken line G3.

[0093] The second water volume W2 is an amount of water greater than or equal to the amount of water predicted to be consumed from the end of the nighttime boiling operation to the end of the first period. In FIG. 3, the amount of hot water above the broken line G2 indicates the amount of water predicted to be consumed from the end of the nighttime boiling operation to the end of the first period. The central diagram of FIG. 3 shows the case where the second water volume W2 is the amount of water predicted to be consumed from the end of the nighttime boiling operation to the end of the first period. In other words, the upper limit of the broken line G1 is the broken line G2.

[0094] Furthermore, the second water volume W2 is less than the water volume obtained by subtracting the first water volume W1 from the capacity of the hot water storage tank 21. In FIG. 3, the amount of hot and cold water above the broken line G3 indicates the water volume obtained by subtracting the first water volume W1 from the capacity of the hot water storage tank 21. The right diagram of FIG. 3 shows the case where the second water volume W2 is the water volume obtained by subtracting the first water volume W1 from the capacity of the hot water storage tank 21. In other words, the lower limit of the broken line G1 is the broken line G3.

[0095] The DR control unit 192 does not boil up the first water volume W1 during the night-time boiling-up operation and boils up the first water volume W1 during the daytime boiling-up operation in the first period in order to increase the power consumption of the boiling-up device 1 in the first period more than usual. In other words, the DR control unit 192 deliberately does not boil up the first water volume W1 during the night-time boiling-up operation and leaves it, in order to boil up the first water volume W1 during the daytime boiling-up operation in the first period.

[0096] The first water volume W1 is, for example, the water volume that can be boiled up by the power consumption required by the upward DR request. Also, the first water volume W1 is, for example, the water volume that can be boiled up by continuously performing the daytime boiling-up operation during the first period.

[0097] The DR control unit 192 may make the heating capacity of the daytime boiling-up operation higher than the heating capacity of the night-time boiling-up operation in order to increase the power consumption of the boiling-up device 1 in the first period more than usual. For example, the DR control unit 192 makes the operating frequency of the motor 11a of the compressor 11 in the daytime boiling-up operation higher than the operating frequency of the motor 11a of the compressor 11 in the night-time boiling-up operation. Also, for example, the DR control unit 192 may make the boiling completion temperature at the end of the daytime boiling-up operation higher than the boiling completion temperature at the end of the night-time boiling-up operation.

[0098] (3) Features (3-1) Conventionally, it has been known to increase the power consumption of the boiling-up device in the first period more than usual in response to a demand response request from an aggregator.

[0099] However, if the water volume predicted to be consumed by the next water heating, for example, is boiled up during the night immediately before the first period, it may not be possible to sufficiently increase the power consumption of the boiling-up device during the first period.

[0100] The water heater 100 of the present embodiment includes a hot water storage tank 21 and a boiling-up device 1. The boiling-up device 1 has a control unit 190. The control unit 190 controls a boiling-up operation for heating the hot water in the hot water storage tank 21. The control unit 190 receives an increase DR request. The increase DR request is a request to increase the power consumption of the boiling-up device 1 during the first period more than usual. The control unit 190 boils up a second water volume W2 by a night boiling-up operation during the night immediately before the first period. The control unit 190 boils up a first water volume W1 by a daytime boiling-up operation during the first period. The second water volume W2 is a water volume equal to or greater than the water volume predicted to be consumed from the end of the second boiling-up operation to the elapse of the first period.

[0101] In the water heater 100 of the present embodiment, when the control unit 190 receives an increase DR request to increase the power consumption of the boiling-up device 1 during the first period more than usual, the control unit 190 boils up a second water volume W2 by a night boiling-up operation during the night immediately before the first period. The second water volume W2 is equal to or greater than the water volume predicted to be consumed from the end of the night boiling-up operation to the elapse of the first period. As a result, since the water heater 100 boils up the water volume predicted to be consumed from the end of the night boiling-up operation to the elapse of the first period during the night immediately before the first period, it is possible to sufficiently increase the power consumption of the boiling-up device 1 during the first period.

[0102] (3-2) In the water heater 100 of the present embodiment, the second water volume W2 is less than the water volume obtained by subtracting the first water volume W1 from the capacity of the hot water storage tank 21.

[0103] (3-3) In the water heater 100 of the present embodiment, the first water volume W1 is a water volume that can be boiled up by the power consumption required by the increase DR request.

[0104] (3-4) In the water heater 100 of the present embodiment, the first water volume W1 is the water volume that can be boiled by continuously performing the daytime boiling operation during the first period.

[0105] (3-5) In the water heater 100 of the present embodiment, the heating capacity of the daytime boiling operation is higher than that of the nighttime boiling operation. As a result, the water heater 100 can increase the power consumption of the boiling device 1 during the first period more than usual.

[0106] (3-6) In the water heater 100 of the present embodiment, the boiling completion temperature at the end of the daytime boiling operation is higher than the boiling completion temperature at the end of the nighttime boiling operation. The boiling completion temperature is the temperature of the water inlet pipe L1 connected to the water heat exchanger 12.

[0107] As a result, the water heater 100 can increase the power consumption of the boiling device 1 during the first period more than usual.

[0108] (4) Modification (4-1) Modification 1A In the present embodiment, when the control unit 190 receives the boost DR request by the reception unit 191, it boils the second water volume W2 by the nighttime boiling operation in the nighttime time zone immediately before the first period. When the consumption of the third water volume of a predetermined amount or more is predicted after the elapse of the first period, the control unit 190 may further boil the third water volume in the nighttime time zone.

[0109] As a result, the water heater 100 can continuously supply hot water at the temperature desired by the user to the user.

[0110] (4-2) Modification 1B In the present embodiment, when the control unit 190 receives the boost DR request by the reception unit 191, it boils the second water volume W2 by the nighttime boiling operation in the nighttime time zone immediately before the first period. When the boost DR request is cancelled before the start of the first period after the elapse of the nighttime time zone, the control unit 190 may boil the first water volume W1 in the daytime time zone after the cancellation of the boost DR request.

[0111] As a result, during the daytime when the outside air temperature is relatively high, the water heater 100 can suppress power consumption and boil the first water volume W1 by boiling the first water volume W1.

[0112] (4-3) Modification Example 1C In the present embodiment, when the control unit 190 receives the raise DR request by the reception unit 191, it boils the second water volume W2 by the night boiling operation in the night time zone immediately before the first period. When the raise DR request is cancelled before the start of the first period after the elapse of the night time zone, the control unit 190 may boil the first water volume W1 by the third boiling operation after the cancellation of the raise DR request. The third boiling operation is a boiling operation with a lower heating capacity than the night boiling operation. For example, the third boiling operation boils the first water volume W1 over a longer time than the night boiling operation.

[0113] As a result, the water heater 100 can suppress power consumption and boil the first water volume W1.

[0114] (4-4) Modification Example 1D In the present embodiment, when the control unit 190 receives the raise DR request by the reception unit 191, it boils the second water volume W2 by the night boiling operation in the night time zone immediately before the first period. When the raise DR request is cancelled in the night time zone, the control unit 190 may further boil the first water volume W1 in the night time zone.

[0115] Normally, the unit price of electricity in the commercial power system is lower at night than during the day. Therefore, the water heater 100 can boil the first water volume W1 while suppressing costs.

[0116] (4-5) Modification Example 1E When the control unit 190 further receives a lower DR request to reduce the power consumption of the boiling device in the third period more than normal after receiving the raise DR request by the reception unit 191, the first water volume W1 boiled by the daytime boiling operation in the first period may be equal to or more than the water volume predicted to be consumed in the third period.

[0117] As a result, the control unit 190 can increase the power consumption of the boiling-up device 1 in the first period and decrease the power consumption of the boiling-up device 1 in the third period.

[0118] Also, in the third period, the control unit 190 may execute the boiling-up operation using the surplus power generated by the solar power generation device. Since the boiling-up operation is executed using the surplus power, the boiling-up device 1 will not consume the power of the commercial power system.

[0119] The solar power generation device is installed on the roof or the like of the facility where the water supply device 100 is installed. The solar power generation device is connected to the first control device 10 and the second control device 20 so as to be capable of two-way data communication by wireless communication or wired communication. The water supply device 100 and other electrical equipment used in the facility can be operated by the power generated by the solar power generation device.

[0120] (4-6) Modification Example 1F In this embodiment, the water supply device 100 directly received the DR request from the aggregator 90. However, the water supply device 100 may receive the DR request from the aggregator 90 via the server.

[0121] For example, when the server receives a DR request for the water supply device 100 from the aggregator 90, the server transmits the received DR request to the water supply device 100 and controls the water supply device 100 according to the received DR request. For example, the server periodically obtains operation data such as the operation frequency of the motor 11a of the compressor 11 from the water supply device 100, compares the power consumption when the DR request is received with the power consumption when the DR request is not received, and can output information for determining the validity of the incentive.

[0122] (4-7) As described above, the embodiments of the present disclosure have been described. It will be understood that various changes in form and details are possible without departing from the spirit and scope of the present disclosure described in the claims.

Explanation of Reference Numerals

[0123] 1 Boiling-up device 12 Heat exchanger 21 Hot water storage tank (tank) 100 Hot water supply device 190 Control unit L1 Water inlet pipe W1 First water volume W2 Second water volume

Prior art documents

Patent documents

[0124]

Patent Document 1

Claims

1. A hot water supply device (100) comprising: a tank (21); and a control unit (190) configured to control a boiling operation for heating hot water in the tank, wherein the control unit: receives a first demand response request to increase power consumption of the boiling device during a first period more than normal; boils a second water volume (W2) by a second boiling operation at night immediately before the first period; boils a first water volume (W1) by a first boiling operation during the first period; and the second water volume is not less than a water volume that is predicted to be consumed from the end of the second boiling operation to the passage of the first period.

2. The hot water supply device (100) according to claim 1, wherein the second water volume is less than a water volume obtained by subtracting the first water volume from a capacity of the tank.

3. The hot water supply device (100) according to claim 1 or 2, wherein the first water volume is a water volume that can be boiled by power consumption required by the first request.

4. The hot water supply device (100) according to claim 1 or 2, wherein the first water volume is a water volume that can be boiled by continuously performing the first boiling operation during the first period.

5. The hot water supply device (100) according to claim 1 or 2, wherein when consumption of a third water volume equal to or more than a predetermined amount is predicted after the passage of the first period, the control unit further boils the third water volume at night.

6. The hot water supply device (100) according to claim 1 or 2, wherein a heating capacity of the first boiling operation is higher than a heating capacity of the second boiling operation.

7. The hot water supply device (100) according to claim 6, wherein a boiling completion temperature, which is a temperature of an inlet water pipe (L1) connected to a water heat exchanger (12) at the completion of boiling of the first boiling operation, is higher than the boiling completion temperature at the completion of boiling of the second boiling operation.

8. The hot water supply device (100) according to claim 1 or 2, wherein when the first request is cancelled after the passage of the night and before the start of the first period, the control unit boils the first water volume during the day after the cancellation of the first request.

9. The hot water supply device (100) according to claim 1 or 2, wherein when the first request is cancelled after the passage of the night and before the start of the first period, the control unit boils the first water volume by a third boiling operation having a lower heating capacity than the second boiling operation after the cancellation of the first request.

10. ​ ​ ​ ​ ​ ​ ​ ​ ​ When the first request is canceled at night, the control unit further boils the first water volume at night. The water heater (100) according to claim 1 or 2.

11. The control unit further receives a second request for demand response to reduce the power consumption of the boiling device in the third period below normal. The first water volume is not less than the water volume predicted to be consumed in the third period. The water heater (100) according to claim 1 or 2.

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