Hot water supply system

Abstract

Provided is a hot water supply system that improves user convenience. 【Solution means】The hot water supply system 100 includes a tank 21 and a control unit 190. The control unit 190 controls the operation of the hot water supply device 1 having the tank 21. The control unit 190 receives a demand response request. When the amount of heat in the tank 21 becomes equal to or less than a first reference value during a second period which is a period other than a first period for suppressing power consumption set based on the demand response request, the control unit 190 performs a boiling operation to heat the hot water in the tank 21. When the amount of heat in the tank 21 becomes equal to or less than the first reference value during the first period, the control unit 190 determines whether or not to perform the boiling operation.

Description

Technical Field

[0001] Relates to a hot water supply system.

Background Art

[0002] Conventionally, there has been known a mechanism for adjusting the power supply-demand balance by requesting a demand response (DR) regarding power consumption or suppression from a power supplier (power company) to a power consumer, and having the power consumer adjust the power consumption amount.

[0003] When receiving a DR request for power reduction (down DR request), the storage type hot water supply device performs a planned boiling operation during time zones other than the time zone based on the down DR request, and stores the heated hot water in the hot water storage tank. Further, when the remaining hot water amount in the hot water storage tank becomes equal to or less than a certain reference value during time zones other than the time zone based on the down DR request, the storage type hot water supply device performs a boiling operation.

[0004] Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2019-105984) discloses a device control device that changes the setting conditions of an air conditioner to the setting conditions desired by the user during the performance of demand response control corresponding to a down DR request. The user selects the desired setting condition from one or more setting conditions posted by the device control device.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The storage type hot water supply device performs a planned boiling operation and automatically maintains the remaining hot water amount in the hot water storage tank at a certain reference value or more. Therefore, in the device control device of Patent Document 1 that requires user selection, the convenience of the user may be reduced.

[0006] The present disclosure provides a hot water supply system that improves user convenience.

Means for Solving the Problems

[0007] The hot water supply system from the first perspective includes a tank and a control unit. The control unit controls the operation of the hot water supply device having the tank. The control unit receives a demand response request. When the amount of heat in the tank becomes equal to or less than a first reference value during a second period, which is a period other than the first period for suppressing the power consumption set based on the demand response request, the control unit performs a boiling-up operation to heat the hot water in the tank. When the amount of heat in the tank becomes equal to or less than the first reference value during the first period, the control unit determines whether to perform the boiling-up operation.

[0008] Prohibiting the boiling-up operation during the first period will reduce the convenience for the user. With such a configuration, the convenience for the user is improved.

[0009] The hot water supply system from the second perspective is the hot water supply system from the first perspective, where the amount of heat in the tank is the remaining amount of hot water in the tank. The first reference value is a first amount of hot water, which is a predetermined amount of hot water.

[0010] The hot water supply system from the third perspective is the hot water supply system from the second perspective. When the control unit determines to perform the boiling-up operation during the first period, the control unit performs the boiling-up operation so that the remaining amount of hot water after the boiling-up operation is equal to or more than the first amount of hot water.

[0011] With such a configuration, the occurrence of running out of hot water can be suppressed. As a result, the convenience for the user is improved.

[0012] The hot water supply system from the fourth perspective is the hot water supply system from the second perspective. When the control unit determines to perform the boiling-up operation during the first period, the control unit performs the boiling-up operation so that the remaining amount of hot water after the boiling-up operation is equal to or more than a second amount of hot water, which is the predicted amount of hot water to be discharged after the end of the first period.

[0013] By boiling up the predicted amount of hot water in advance, there is no need to perform the boiling-up operation again, and the operating efficiency of the hot water supply device is improved. Also, by preparing in advance for the predicted hot water discharge, the convenience for the user is improved.

[0014] The hot water supply system from the fifth perspective is the hot water supply system from any of the first to fourth perspectives, and when the amount of heat in the tank becomes equal to or less than the first reference value during the first period, the control unit does not perform the boiling-up operation.

[0015] With such a configuration, it is possible to respond to the lowering DR request.

[0016] The hot water supply system from the sixth perspective is the hot water supply system from the fifth perspective, and the control unit performs the boiling-up operation after the first period has elapsed.

[0017] With such a configuration, it is possible to respond to the lowering DR request.

[0018] The hot water supply system from the seventh perspective is the hot water supply system from the fifth or sixth perspective. When there is a planned hot water discharge after the first period has elapsed, the control unit performs the boiling-up operation during the period from after the first period has elapsed to the planned hot water discharge time.

[0019] With such a configuration, it is possible to respond to the lowering DR request. Also, by preparing in advance for the planned hot water discharge, the convenience for the user is improved.

[0020] The hot water supply system from the eighth perspective is the hot water supply system from any of the fifth to seventh perspectives, and the control unit performs the boiling-up operation within a predetermined first hour after the first period has elapsed.

[0021] With such a configuration, it is possible to respond to the lowering DR request. Also, by preparing in advance for the hot water discharge, the convenience for the user is improved.

[0022] The hot water supply system from the ninth perspective is the hot water supply system from any of the fifth to eighth perspectives. After the control unit determines not to perform the boiling-up operation, no hot water discharge based on the hot water discharge instruction is performed during the period from after the determination to the end time of the first period.

[0023] With such a configuration, it is possible to respond to the lowering DR request.

[0024] The hot water supply system from the 10th perspective is the hot water supply system from the 2nd perspective, and when the remaining hot water volume is less than the first hot water volume and less than or equal to the third hot water volume, the control unit performs a boiling-up operation.

[0025] With such a configuration, the occurrence of running out of hot water can be suppressed. As a result, the convenience for the user is improved.

[0026] The hot water supply system from the 11th perspective is the hot water supply system from the 10th perspective, and when the remaining hot water volume is greater than the third hot water volume and less than or equal to the first hot water volume, the control unit suppresses the boiling-up operation.

[0027] With such a configuration, while suppressing power consumption, the occurrence of running out of hot water can be suppressed. As a result, it is possible to respond to the downward DR request, and the convenience for the user is improved.

[0028] The hot water supply system from the 12th perspective is the hot water supply system from any one of the 2nd, 3rd, 4th, 10th, and 11th perspectives, and the control unit determines whether to perform a boiling-up operation according to the second time from the time when the remaining hot water volume becomes less than or equal to the first hot water volume to the end time of the first period.

[0029] By determining whether to perform a boiling-up operation according to the time until the end of the downward DR period, the convenience for the user is improved.

[0030] The hot water supply system from the 13th perspective is the hot water supply system from the 12th perspective, and when the second time is greater than or equal to the predetermined third time, the control unit performs a boiling-up operation.

[0031] With such a configuration, the convenience for the user is improved.

[0032] The hot water supply system from the 14th perspective is the hot water supply system from the 12th or 13th perspective, and when the second time is less than the predetermined third time, the control unit does not perform a boiling-up operation.

[0033] With such a configuration, it is possible to respond to the downward DR request.

[0034] The hot water supply system of the 15th aspect is the hot water supply system of the 13th or 14th aspect, and the third hour is set by the user.

[0035] With such a configuration, the convenience of the user is improved.

[0036] The hot water supply system of the 16th aspect is the hot water supply system of any one of the 1st to 15th aspects, and the control unit controls the operation of two or more hot water supply devices. When performing a boiling operation with one hot water supply device in the first period, the control unit restricts the operation of other hot water supply devices.

[0037] With such a configuration, it is possible to respond to a lowering DR request.

[0038] The hot water supply system of the 17th aspect is the hot water supply system of any one of the 1st to 16th aspects, and the control unit sets the power consumption reduction target value to a value equal to or higher than the power consumption reduction level value set based on the demand response request.

[0039] With such a configuration, it is possible to respond to a lowering DR request.

[0040] The hot water supply system of the 18th aspect is the hot water supply system of any one of the 1st to 17th aspects, and the control unit restricts the number of hot water supply devices performing a boiling operation in the first period.

[0041] With such a configuration, it is possible to respond to a lowering DR request.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2

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Figure 7

Mode for Carrying Out the Invention

[0043] <First Embodiment> (1) Overall Configuration The hot water supply system 100 according to the first embodiment will be described with reference to the drawings.

[0044] The hot water supply system 100 adjusts the power consumption of the commercial power system in response to a demand response request (hereinafter sometimes referred to as a DR request).

[0045] Demand response is that a user (consumer) receiving power supply from the 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 a user a reward that is the consideration for the demand response according to the adjustment amount of the power consumption of the commercial power system.

[0046] FIG. 1 is a schematic configuration diagram of the hot water supply system 100. As shown in FIG. 1, the hot water supply system 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 unit 140, a bathtub 150, and a stop valve 160 are connected to the hot water storage unit 120.

[0047] 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 it 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 hot water supply device 1 that boils the hot water in the hot water storage tank (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.

[0048] Here, "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.

[0049] (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.

[0050] 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. It is preferable that the critical temperature of the refrigerant is 10°C or more 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).

[0051] 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 heating capacity of the heat pump unit 110 can be adjusted by controlling the operating frequency of the motor 11a.

[0052] 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 be a plate-type heat exchanger or the like. The heating 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.

[0053] The expansion valve 13 decompresses 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 be a capillary tube or the like.

[0054] The air heat exchanger 14 performs heat exchange between the refrigerant decompressed by passing through the expansion valve 13 and the outside air to heat the refrigerant. The outside air is supplied to the air heat exchanger 14 by, for example, an outside air fan. The refrigerant that has passed through the air heat exchanger 14 and undergone heat exchange is sent to the compressor 11.

[0055] (2-2) Hot water storage unit The hot water storage unit 120 mainly includes a hot water storage tank 21, a first drain valve 22, a water inlet valve 23, a boiling pump 24, a bypass valve 25, a boiling 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 supplementary heating pump 34, and a supplementary heating heat exchanger 35. These elements are connected by pipes L1 to L19 through which hot and cold water flows. Temperature sensors T1 to T10 are provided in the hot water storage tank 21 and pipes L10, L13, L14, and L16. The hot water storage unit 120 also has a second control device 20.

[0056] The hot water storage tank 21 stores hot and cold water. Six temperature sensors T1 to T6 are provided in the hot water storage tank 21. The six temperature sensors T1 to 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 face of the hot water storage tank 21. The first to fifth hot water volume temperature sensors T1 to T5 are provided on the side surface of the hot water storage tank 21 at intervals from the upper side to the lower side.

[0057] 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 to 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 (remaining hot water amount) in the hot water storage tank 21 can be obtained. The number of temperature sensors provided in the hot water storage tank 21 for obtaining the remaining hot water amount may be any number other than 6.

[0058] One end of the water inlet pipe L1 is connected to the lower end face 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. An inlet valve 23, a boiling pump 24, and a bypass valve 25 are provided in the water inlet pipe L1 from the hot water storage tank 21 toward the water heat exchanger 12. The inlet valve 23 and the bypass valve 25 are electric three-way valves.

[0059] The first drain pipe L2 branches off 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.

[0060] 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 - up valve 26. The boiling - up valve 26 is an electric three - way valve.

[0061] One end of the first return pipe L4 is connected to the boiling - up 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.

[0062] One end of the second return pipe L5 is connected to the boiling - up 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.

[0063] 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.

[0064] One end of the first boiling - up pipe L7 is connected to the upper end surface of the hot water storage tank 21, and the other end of the first boiling - up pipe L7 is connected to the first mixing valve 27. The first mixing valve 27 is an electric three - way valve.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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. Between the first flow rate sensor 30 and the hot water supply unit 140, a first hot water supply temperature sensor T8 is provided in the first hot water supply pipe L13. The first hot water supply temperature sensor T8 detects the temperature of the hot water flowing in the first hot water supply pipe L13.

[0069] 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 towards 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.

[0070] 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 to discharge a part of the hot water flowing through the second hot water supply pipe L14 to the outside, for example, to adjust the amount of hot water flowing through the second hot water supply pipe L14.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] (2-3) Remote Controller The remote controller 130 is a user interface for controlling the water heater 1. 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 1 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 may be used as a user interface of the water heater 1.

[0076] 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.

[0077] The display unit 130a displays information related to the state of the water heater 1 and information related to the settings of the water heater 1. For example, the display unit 130a displays 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 remaining hot water amount in the hot water storage tank 21.

[0078] The operation unit 130b includes buttons, dials, keys, etc. for the user of the water heater 1 to operate. The user of the water heater 1 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 serves as the function of the operation unit 130b.

[0079] 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.

[0080] (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 1 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.

[0081] 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 providing the first control device 10 and the second control device 20, a device having the functions of both the first control device 10 and the second control device 20 and provided in either the heat pump unit 110 or the hot water storage unit 120 may be provided. Such a device may be installed outside the water supply device 1 and connected to the heat pump unit 110 and the hot water storage unit 120 via a network.

[0082] Figure 2 is a functional block diagram of the water supply system 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, and the afterburning pump 34, etc., based on the signals from the temperature sensors T1 to 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.

[0083] The control unit 190 mainly performs boiling operation, water supply operation, hot water discharge operation, and afterburning operation. Also, as functional blocks, the control unit 190 has a receiving unit 191 and a DR control unit 192.

[0084] (2-4-1) Heating-up operation The heating-up operation is an operation of heating the hot water in the hot water storage tank 21 by the heat pump unit 110. In the heating-up operation, by driving the boiling-up 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 heating-up operation, the hot water in the hot water storage tank 21 is circulated through the water inlet pipe L1, the hot water outlet pipe L3, the first return pipe L4, and the second return pipe L5, and heated in the water heat exchanger 12.

[0085] The control unit 190 performs the heating-up operation by controlling the compressor 11, the expansion valve 13, the water inlet valve 23, the boiling-up pump 24, the bypass valve 25, and the boiling-up 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 heating capacity of the heat pump unit 110 and the temperature (hot water outlet temperature) of the hot water heated in the water heat exchanger 12, etc. The control unit 190 controls the rotation speed of the boiling-up pump 24 to adjust the hot water outlet temperature, the remaining hot water 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.

[0086] In the normal heating-up 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.

[0087] 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.

[0088] The control unit 190 can control the boiling-up valve 26 to switch between a state where 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 where hot water is supplied from the water heat exchanger 12 to the hot water storage tank 21 via the second return pipe L5.

[0089] The control unit 190 may acquire the hot water output temperature, the remaining 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 to T6 of the hot water storage tank 21.

[0090] 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 output temperature, the remaining hot water amount, and the storage flow rate reach predetermined target values.

[0091] The control unit 190 executes a boiling-up operation using the power of the commercial power system. The time zone for executing the boiling-up operation may be set by the user of the water supply device 1 operating the remote controller 130.

[0092] When the amount of heat in the hot water storage tank 21 becomes equal to or less than the first reference value, the control unit 190 executes a boiling-up operation. In the present embodiment, the amount of heat in the hot water storage tank 21 is the remaining hot water amount. The first reference value is the first hot water amount W1 which is a predetermined hot water amount.

[0093] Here, the amount of hot water used when the user takes a bath with a bathtub or a shower is generally 50 liters per person. If the remaining hot water amount is less than 50 liters, there is a high possibility of running out of hot water when taking a bath. Therefore, the predetermined first hot water amount W1 is, for example, 50 liters.

[0094] (2-4-2) Hot water supply operation The hot water supply operation is an operation to discharge the hot water in the hot water storage tank 21 from the hot water supply section 140. In the hot water supply operation, when the hot water supply section 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. Thereby, the high-temperature hot water stored in the hot water storage tank 21 is pushed out from the upper part in the hot water storage tank 21 through the first boiling-up pipe L7.

[0095] 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 section 140 through the first hot water supply pipe L13.

[0096] When the hot water supply section 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 section 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 section 140.

[0097] 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 section 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.

[0098] The time period during which the hot water supply operation is executed and the amount of hot water used are accumulated in the storage device as, for example, hot water discharge history information.

[0099] (2-4-3) 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 in the hot water storage tank 21 through the second boiling-up pipe L8.

[0100] 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.

[0101] 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, the control unit 190 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.

[0102] 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 and the like.

[0103] During the hot water filling operation, the control unit 190 may receive an end signal for the hot water filling operation by the user's operation of the remote controller 130, or may close the hot water filling solenoid valve 31 to end the hot water filling operation 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.

[0104] The time zone for executing the hot water filling operation may be set by the user of the water supply apparatus 1 operating the remote controller 130. The time zone for executing the hot water filling operation and the amount of hot water to be used are stored in the storage device as, for example, hot water supply schedule information.

[0105] (2-4-4) Supplementary heating operation The supplementary heating operation is an operation in which the hot water in the bathtub 150 is heated in the supplementary heating heat exchanger 35 and then returned to the bathtub 150. In the supplementary heating operation, by driving the supplementary heating pump 34, a part of the hot water in the bathtub 150 is guided to the supplementary heating heat exchanger 35 through the first bathtub return pipe L16 and heated. The hot water heated in the supplementary heating heat exchanger 35 is returned to the bathtub 150 through the second bathtub return pipe L17 and the second water supply pipe L14. Thus, in the supplementary heating 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 water supply pipe L14, and is heated in the supplementary heating heat exchanger 35.

[0106] The supplementary heating heat exchanger 35 performs heat exchange between the high-temperature hot water supplied from the hot water storage tank 21 through the second water supply pipe L14 and the first supplementary heating pipe L18, and the low-temperature hot water supplied from the bathtub 150 through the first bathtub return pipe L16. Thereby, the supplementary heating 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 supplementary heating heat exchanger 35 through the first supplementary heating pipe L18 is supplied to the water supply pipe L1 through the second supplementary heating pipe L19 and the water inlet valve 23 after heat exchange. The supplementary heating 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 and heat exchange is performed.

[0107] When the control unit 190 receives a start signal for the post-combustion operation by the user's operation of the remote controller 130, 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.

[0108] 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.

[0109] Also, during the execution of the post-combustion operation, when the control unit 190 receives an end signal for the post-combustion operation by the user's operation of the remote controller 130, 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.

[0110] The time period when the post-combustion operation is executed and the amount of hot water used are accumulated in the storage device as, for example, hot water discharge history information.

[0111] (2-4-5) Receiver The receiver 191 receives a DR request from the aggregator 90 via the network NW. The DR request includes a down DR request and an up DR request.

[0112] The lowering DR request is a request to reduce the power consumption of the water heater 1 during the first period below normal. The aggregator 90 makes a lowering DR request to the control unit 190 before the arrival of the first period predicted to have a tight supply of commercial power grid electricity.

[0113] The raising DR request is a request to increase the power consumption of the water heater 1 during the second period above normal. The aggregator 90 makes a raising DR request to the control unit 190 before the arrival of the second period predicted to have an excess supply of commercial power grid electricity.

[0114] The lowering DR request and the raising DR request may include target values related to power consumption.

[0115] (2-4-6) DR control unit The DR control unit 192 controls not to perform the boiling-up operation during the first period. However, as described later, if the DR control unit 192 determines to perform the boiling-up operation, it performs the boiling-up operation.

[0116] When the remaining hot water amount becomes less than or equal to the first hot water amount W1 during the first period, the DR control unit 192 determines whether to perform the boiling-up operation. The first hot water amount W1 is stored in the storage device in advance. The first hot water amount W1 may be set by the user operating the remote controller 130.

[0117] When the remaining hot water amount becomes less than or equal to the first hot water amount W1, as shown in the flowchart of FIG. 3, the DR control unit 192 determines whether to perform the boiling-up operation according to the remaining hot water amount.

[0118] When the remaining hot water amount becomes less than or equal to the first hot water amount W1, the DR control unit 192 determines whether it is the first period (step S11). If it is not the first period (NO in step S11), the DR control unit 192 does not determine whether to perform the boiling-up operation. In this case, the control unit 190 executes the boiling-up operation as usual.

[0119] When it is the first period (when YES in step S11), the DR control unit 192 determines whether the remaining hot water amount is equal to or less than the third hot water amount W3 (step S12). The third hot water amount W3 is a hot water amount smaller than the first hot water amount W1, and is, for example, 15 liters. When the remaining hot water amount is equal to or less than the third hot water amount W3, the possibility of hot water running out increases.

[0120] FIG. 4 is a diagram for explaining the first hot water amount W1, the second hot water amount W2, and the third hot water amount W3. 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 FIG. 4, the first hot water amount W1 is the amount of hot water above the broken line G1. The third hot water amount W3 is a hot water amount smaller than the first hot water amount W1, and is the amount of hot water above the broken line G3.

[0121] When the remaining hot water amount is greater than the third hot water amount W3 (when NO in step S12), the DR control unit 192 determines not to perform the boiling-up operation (step S16).

[0122] On the other hand, when the remaining hot water amount is equal to or less than the third hot water amount W3 (when YES in step S12), the DR control unit 192 determines to perform the boiling-up operation (step S13).

[0123] Based on the hot water discharge history information regarding the time period when the hot water supply operation was executed, the time period when the post-boiling operation was executed, and the amount of hot water used, the DR control unit 192 determines whether there is a hot water discharge plan after the end of the first period (step S14). Also, the DR control unit 192 determines whether there is a hot water discharge plan after the end of the first period based on the hot water discharge plan information regarding the time period when the hot water draining operation is executed and the amount of hot water used (step S14). Note that after the end of the first period is within a predetermined fourth time from the end time of the first period.

[0124] When it is determined that there is a planned hot water discharge after the end of the first period (YES in step S14), the DR control unit 192 determines to boil up more than the second hot water amount W2 in the boiling-up operation (step S15). The second hot water amount W2 is the amount of hot water planned to be discharged after the end of the first period (planned hot water discharge amount). The DR control unit 192 calculates the second hot water amount W2 based on the hot water discharge history information and the planned hot water discharge information. As shown in FIG. 4, the second hot water amount W2 is the amount of hot water above the broken line G2. In other words, when the remaining hot water amount is equal to or less than the third hot water amount W3 and there is a planned hot water discharge after the end of the first period, the DR control unit 192 determines to boil up more than the planned hot water discharge amount in the boiling-up operation.

[0125] On the other hand, when it is determined that there is no planned hot water discharge after the end of the first period (NO in step S14), the DR control unit 192 determines to boil up more than the first hot water amount W1 in the boiling-up operation (step S17). In other words, when the remaining hot water amount is equal to or less than the third hot water amount W3 and there is no planned hot water discharge after the end of the first period, the DR control unit 192 determines to boil up more than the first hot water amount W1 in the boiling-up operation.

[0126] (3) Features (3-1) Conventionally, there is known a device control device that changes the set conditions of an air conditioner to the set conditions desired by the user while demand response control corresponding to a lowering DR request is being performed. The user selects the desired set conditions from one or more set conditions posted by the device control device.

[0127] However, the storage-type water supply device performs a boiling-up operation in a planned manner and automatically keeps the remaining hot water amount in the storage tank above a certain reference value. Therefore, in the device control device of Patent Document 1 that requires user selection, the convenience for the user may be reduced.

[0128] The hot water supply system 100 of this embodiment includes a hot water storage tank 21 and a control unit 190. The control unit 190 controls the operation of the hot water supply device 1 having the hot water storage tank 21. The control unit 190 receives a demand response request. When the amount of heat in the hot water storage tank 21 becomes equal to or less than a first reference value in a second period, which is a period other than the first period for suppressing the power consumption set based on the demand response request, the control unit 190 performs a boiling-up operation to heat the hot water in the hot water storage tank 21. When the amount of heat in the hot water storage tank 21 becomes equal to or less than the first reference value in the first period, the control unit 190 determines whether to perform the boiling-up operation.

[0129] If the boiling-up operation is prohibited during the first period, the convenience for the user will decrease. With such a configuration, the convenience for the user is improved.

[0130] (3-2) In the hot water supply system 100 of this embodiment, the amount of heat in the hot water storage tank 21 is the remaining amount of hot water in the hot water storage tank 21. The first reference value is a first hot water amount W1, which is a predetermined amount of hot water.

[0131] (3-3) In the hot water supply system 100 of this embodiment, when the control unit 190 determines to perform the boiling-up operation during the first period, the control unit 190 performs the boiling-up operation so that the remaining amount of hot water after the boiling-up operation is equal to or more than the first hot water amount W1.

[0132] With such a configuration, the occurrence of running out of hot water can be suppressed. As a result, the convenience for the user is improved.

[0133] (3-4) In the hot water supply system 100 of this embodiment, when the control unit 190 determines to perform the boiling-up operation during the first period, the control unit 190 performs the boiling-up operation so that the remaining amount of hot water after the boiling-up operation is equal to or more than a second hot water amount W2, which is the estimated hot water supply amount after the end of the first period.

[0134] By pre-boiling the estimated hot water supply amount, it is not necessary to perform the boiling-up operation again, and the operation efficiency of the hot water supply device 1 is improved. Also, by preparing in advance for the estimated hot water supply, the convenience for the user is improved.

[0135] (3 - 5) In the hot water supply system 100 of this embodiment, when the remaining hot water amount is less than or equal to the third hot water amount W3 which is less than the first hot water amount W1, the control unit 190 performs a boiling operation.

[0136] With such a configuration, the occurrence of running out of hot water can be suppressed. As a result, the convenience for the user is improved.

[0137] (4) Modification (4 - 1) Modification 1A In this embodiment, when the remaining hot water amount is greater than the third hot water amount W3 and less than or equal to the first hot water amount W1, the DR control unit 192 determines not to perform a boiling operation. However, the DR control unit 192 may also determine to suppress the boiling operation when the remaining hot water amount is greater than the third hot water amount W3 and less than or equal to the first hot water amount W1. Specifically, the DR control unit 192 may determine to perform a boiling operation with a heating capacity smaller than the standard heating capacity. Note that the standard heating capacity is the heating capacity in a normal boiling operation, and indicates the heating capacity based on the rated power using commercial power (the maximum value of the power that can be used in a continuous operation state at a specified ambient temperature).

[0138] With such a configuration, it is possible to suppress the occurrence of running out of hot water while suppressing power consumption. As a result, it is possible to respond to a lower DR request, and the convenience for the user is improved.

[0139] (4 - 2) Modification 1B In this embodiment, when the remaining hot water amount is less than or equal to the third hot water amount W3, the DR control unit 192 determines to perform a boiling operation. However, the DR control unit 192 may also determine to perform a boiling operation when the remaining hot water amount is less than or equal to the first hot water amount W1.

[0140] With such a configuration, the occurrence of running out of hot water can be suppressed. As a result, the convenience for the user is improved.

[0141] (4 - 3) Modification 1C In this embodiment, the amount of heat in the hot water storage tank 21 is the remaining amount of hot water in the hot water storage tank 21. The first reference value is the first hot water amount W1 which is a predetermined hot water amount. However, the amount of heat in the hot water storage tank 21 may be the temperature of the hot water at a predetermined temperature sensor among the temperature sensors T1 to T6 provided in the hot water storage tank 21. The first reference value may be a predetermined temperature.

[0142] <Second Embodiment> The hot water supply system 200 according to the second embodiment will be described with reference to the drawings. The basic configuration and operation of the hot water supply system 200 are the same as those of the hot water supply system 100 of the first embodiment. Hereinafter, the hot water supply system 200 of the second embodiment will be described focusing on the differences from the hot water supply system 100 of the first embodiment.

[0143] The control unit 290 mainly performs a boiling operation, a hot water supply operation, a water pouring operation, and a supplementary heating operation. Further, the control unit 290 has, as functional blocks, a reception unit 291 and a DR control unit 292. Since the reception unit 291 is the same as the reception unit 191, the description thereof will be omitted.

[0144] (1) DR Control Unit When the remaining hot water amount becomes equal to or less than the first hot water amount W1 in the first period, the DR control unit 292 determines not to perform the boiling operation. The first hot water amount W1 is stored in the storage device in advance. The first hot water amount W1 may be set by the user operating the remote controller 130.

[0145] When the remaining hot water amount becomes equal to or less than the first hot water amount, the DR control unit 292 determines the schedule of the boiling operation after the first period according to the hot water supply schedule as shown in the flowchart of FIG. 5.

[0146] When the remaining hot water amount becomes equal to or less than the first hot water amount W1, the DR control unit 292 determines whether it is the first period (step S21). If it is not the first period (NO in step S21), the DR control unit 292 does not determine whether to perform the boiling operation. In this case, the control unit 290 executes the boiling operation as usual.

[0147] In the case of the first period (when YES in step S21), the DR control unit 292 determines not to perform the boiling-up operation (step S22).

[0148] The DR control unit 292 determines whether there is a hot water supply plan after the end of the first period based on the hot water supply history information (step S23). Also, the DR control unit 292 determines whether there is a hot water supply plan after the end of the first period based on the hot water supply plan information (step S23).

[0149] When it is determined that there is a hot water supply plan after the end of the first period (when YES in step S23), the DR control unit 292 determines to perform the boiling-up operation during the period until the hot water supply planned time after the first period has elapsed (step S24). The DR control unit 292 may store the time zone for executing the boiling-up operation in the storage device. Note that after the end of the first period means within a predetermined fourth hour from the end time of the first period.

[0150] On the other hand, when it is determined that there is no hot water supply plan after the end of the first period (when NO in step S23), the DR control unit 292 determines to perform the boiling-up operation within a predetermined first hour after the first period has elapsed (step S25). The DR control unit 292 may store the time zone for executing the boiling-up operation in the storage device. The first hour is, for example, 30 minutes. In this case, the DR control unit 292 determines to perform the boiling-up operation within 30 minutes after the first period has elapsed.

[0151] (2) Features (2-1) In the hot water supply system 200 of the present embodiment, when the heat quantity in the hot water storage tank 21 becomes equal to or less than the first reference value during the first period, the control unit 290 does not perform the boiling-up operation.

[0152] With such a configuration, the power consumption by the hot water supply device 1 during the first period can be suppressed, and it is possible to respond to the DR request reduction.

[0153] (2-2) In the hot water supply system 200 of this embodiment, the control unit 290 performs a boiling operation after the first period has elapsed.

[0154] With such a configuration, it is possible to suppress the power consumption by the hot water supply device 1 during the first period and respond to the downward DR request.

[0155] (2-3) In the hot water supply system 200 of this embodiment, when there is a scheduled hot water supply after the first period has elapsed, the control unit 290 performs a boiling operation during the period from after the first period has elapsed until the scheduled hot water supply time.

[0156] With such a configuration, it is possible to suppress the power consumption by the hot water supply device 1 during the first period and respond to the downward DR request. Also, by preparing in advance for the scheduled hot water supply, the convenience for the user is improved.

[0157] (2-4) In the hot water supply system 200 of this embodiment, the control unit 290 performs a boiling operation within a predetermined first hour after the first period has elapsed.

[0158] With such a configuration, it is possible to suppress the power consumption by the hot water supply device 1 during the first period and respond to the downward DR request. Also, by preparing in advance for the hot water supply, the convenience for the user is improved.

[0159] (3) Modification (3-1) Modification 2A After determining not to perform the boiling operation, the DR control unit 292 may control so as not to perform hot water supply based on the hot water supply instruction during the period from after the determination until the end time of the first period.

[0160] With such a configuration, it is possible to suppress the power consumption by the hot water supply device 1 during the first period and respond to the downward DR request.

[0161] <Third Embodiment> The hot water supply system 300 according to the third embodiment will be described with reference to the drawings. The basic configuration and operation of the hot water supply system 300 are the same as those of the hot water supply system 100 in the first embodiment. Hereinafter, the hot water supply system 300 of the third embodiment will be described centering on the differences from the hot water supply system 100 of the first embodiment.

[0162] The control unit 390 mainly performs a boiling operation, a hot water supply operation, a water filling operation, and a post-boiling operation. The control unit 390 includes a receiving unit 391 and a DR control unit 392 as functional blocks. Since the receiving unit 391 is the same as the receiving unit 191, the description thereof is omitted.

[0163] (1) DR control unit The DR control unit 392 controls not to perform a boiling operation during the first period. However, as described later, when the DR control unit 392 determines to perform a boiling operation, it performs a boiling operation.

[0164] The DR control unit 392 determines whether to perform a boiling operation when the remaining hot water amount becomes equal to or less than the first hot water amount W1 during the first period. The first hot water amount W1 is stored in the storage device in advance. The first hot water amount W1 may be set by the user operating the remote controller 130.

[0165] When the remaining hot water amount becomes equal to or less than the first hot water amount W1, the DR control unit 392 determines whether to perform a boiling operation according to the second time as shown in the flowchart of FIG. 6.

[0166] When the remaining hot water amount becomes equal to or less than the first hot water amount W1, the DR control unit 392 determines whether it is the first period (step S31). If it is not the first period (NO in step S31), the DR control unit 392 does not determine whether to perform a boiling operation. In this case, the control unit 390 executes a boiling operation as usual.

[0167] In the case of the first period (when YES in step S31), the DR control unit 392 calculates a second time from the time when the remaining hot water amount becomes equal to or less than the first hot water amount to the end time of the first period (step S32). The time when the remaining hot water amount becomes equal to or less than the first hot water amount may be the current time. The end time of the first period may be included in the lowering DR request.

[0168] When the second time is less than a predetermined third time (when NO in step S33), the DR control unit 392 determines not to perform the boiling-up operation (step S35). The third time is a time set by the user and is a time during which it is possible to wait for the boiling-up operation. The user can input the third time by operating the remote controller 130.

[0169] On the other hand, when the second time is equal to or greater than the third time (when YES in step S33), the DR control unit 392 determines to perform the boiling-up operation (step S34).

[0170] (2) Features (2-1) In the hot water supply system 300 of the present embodiment, the control unit 390 determines whether to perform the boiling-up operation according to the second time from the time when the remaining hot water amount becomes equal to or less than the first hot water amount to the end time of the first period.

[0171] By determining whether to perform the boiling-up operation according to the time until the end of the lowering DR period, the convenience for the user is improved.

[0172] (2-2) In the hot water supply system 300 of the present embodiment, when the second time is equal to or greater than a predetermined third time, the control unit 390 performs the boiling-up operation.

[0173] Since the boiling-up operation is performed when the second time is equal to or greater than the third time during which the user can wait for the gushing-up operation, the convenience for the user is improved.

[0174] (2-3) In the hot water supply system 300 of this embodiment, when the second time is less than a predetermined third time, the boiling operation is not performed.

[0175] When the second time is less than the third time during which the user can wait for the boiling operation, the boiling operation is not performed. With such a configuration, power consumption due to the boiling operation can be suppressed, and it is possible to respond to the reduction DR request.

[0176] (2-4) In the hot water supply system 300 of this embodiment, the third time is set by the user.

[0177] With such a configuration, the user can set the desired time, improving the convenience for the user.

[0178] (3) Modification (3-1) Modification 3A In this embodiment, the DR control unit 392 determines whether to perform the boiling operation according to the second time. However, the DR control unit 392 may determine whether to perform the boiling operation by combining the second time and the remaining hot water amount. Further, the DR control unit 392 may determine whether to perform the boiling operation by combining the second time, the remaining hot water amount, and the planned hot water output.

[0179] For example, even when the second time is less than the third time, the DR control unit 392 may determine to perform the boiling operation when the remaining hot water amount is less than the third hot water amount W3.

[0180] Also, for example, even when the second time is less than the third time, the DR control unit 392 may determine to perform the boiling operation when there is a planned hot water output after the first period has elapsed.

[0181] Also, for example, even when the second time is greater than or equal to the third time, the DR control unit 392 may determine not to perform the boiling operation when there is no planned hot water output after the first period has elapsed.

[0182] With such a configuration, the convenience for the user is further improved.

[0183] <Fourth Embodiment> The hot water supply system 400 according to the fourth embodiment will be described with reference to the drawings.

[0184] As shown in FIG. 7, the hot water supply system 400 according to the fourth embodiment includes two or more hot water supply devices 4. The basic configuration and operation of each hot water supply device 4 are the same as those of the hot water supply device 1 in the first embodiment. Hereinafter, the hot water supply system 400 of the fourth embodiment will be described focusing on the differences from the hot water supply system 100 of the first embodiment.

[0185] The control unit 490 mainly performs a boiling operation, a hot water supply operation, a water pouring operation, and a reheating operation on each hot water supply device 4. The control unit 490 also includes a receiving unit 491 and a DR control unit 492 as functional blocks. Since the receiving unit 491 is the same as the receiving unit 191, the description thereof will be omitted.

[0186] (1) DR Control Unit When the DR control unit 492 performs a boiling operation with one hot water supply device 4 in the first period, it restricts the operation of other hot water supply devices 4.

[0187] Specifically, the DR control unit 492 restricts the number of hot water supply devices 4 performing a boiling operation in the first period. The DR control unit 492 sets the reduction target value of power consumption to a value equal to or higher than the target value (reduction level value) regarding the power consumption included in the DR request. The DR control unit 492 calculates the restricted number of hot water supply devices 4 based on the reduction target value. Information associating the reduction target value and the restricted number may be stored in the storage device in advance as reference information. The DR control unit 492 may determine the restricted number based on the reference information.

[0188] The DR control unit 492 stores in the storage device the number of water heaters 4 that have performed the boiling operation during the first period. When the boiling operation of the water heater 4a has already started for the limited number of units and an instruction for the boiling operation of the water heater 4b is received, the DR control unit 492 determines not to perform the boiling operation of the water heater 4b.

[0189] (2) Features (2-1) In the water supply system 400 of the present embodiment, the control unit 490 controls the operation of two or more water heaters 4. When the control unit 490 performs the boiling operation with one water heater 4 during the first period, it restricts the operation of the other water heaters 4.

[0190] With such a configuration, the power consumption of the entire plurality of water heaters 4 can be restricted. As a result, it is possible to respond to the downward DR request.

[0191] (2-2) In the water supply system 400 of the present embodiment, the control unit 490 sets the power consumption reduction target value to a value equal to or higher than the power consumption reduction level value set based on the demand response request.

[0192] With such a configuration, even when performing the boiling operation of one or more water heaters 4, the power consumption of the entire plurality of water heaters 4 can be restricted. As a result, it is possible to respond to the downward DR request.

[0193] (2-3) In the water supply system 400 of the present embodiment, the control unit 490 restricts the number of water heaters 4 that perform the boiling operation during the first period.

[0194] With such a configuration, the power consumption of the entire plurality of water heaters 4 can be restricted. As a result, it is possible to respond to the downward DR request.

[0195] (3) Modification (3-1) Modification 4A In this embodiment, the DR control unit 492 restricts the number of water heaters 4 that perform boiling operation during the first period. However, when performing the boiling operation with one water heater 4, the DR control unit 492 may determine to perform the boiling operation with a heating capacity smaller than the standard heating capacity for other water heaters 4. The standard heating capacity refers to the heating capacity in a normal boiling operation, and indicates the heating capacity based on the rated power using commercial power (the maximum value of the power that can be used in a continuous operation state at a specified ambient temperature).

[0196] With such a configuration, the power consumption of the plurality of water heaters 4 as a whole can be restricted. As a result, it is possible to respond to the DR request for reduction.

[0197] 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 Signs

[0198] 1 Water heater 4 Water heaters 21 Hot water storage tank, tank 100 Hot water supply system 190 Control unit 200 Hot water supply system 290 Control unit 300 Hot water supply system 390 Control unit 400 Hot water supply system 490 Control unit

Prior Art Documents

Patent Documents

[0199]

Patent Document 1

Claims

1. A tank (21), a control unit (190, 290, 390, 490) that controls the operation of a water heating apparatus (1, 4) having the tank, and the control unit receives a demand response request, and when the amount of heat in the tank becomes equal to or less than a first reference value in a second period which is a period other than a first period for suppressing power consumption set based on the demand response request, performs a boiling-up operation to heat the hot water in the tank, in the first period, when the amount of heat in the tank becomes equal to or less than the first reference value, determines whether to perform the boiling-up operation, in the case where the amount of heat in the tank becomes equal to or less than the first reference value in the first period and it is determined to perform the boiling-up operation, performs the boiling-up operation based on the determination, in the case where the amount of heat in the tank becomes equal to or less than the first reference value in the first period and it is determined not to perform the boiling-up operation, does not perform the boiling-up operation based on the determination, a water heating system (100, 200, 300, 400).

2. The amount of heat in the tank is the remaining hot water amount of the tank, and the first reference value is a first hot water amount which is a predetermined hot water amount, The water heating system according to claim 1.

3. When the control unit determines to perform the boiling-up operation in the first period, the control unit performs the boiling-up operation so that the remaining hot water amount after the boiling-up operation becomes equal to or more than the first hot water amount, The water heating system according to claim 2.

4. When the control unit determines to perform the boiling-up operation in the first period, the control unit performs the boiling-up operation so that the remaining hot water amount after the boiling-up operation becomes equal to or more than a second hot water amount which is the estimated hot water supply amount after the end of the first period, The water heating system according to claim 2.

5. When the amount of heat in the tank becomes equal to or less than the first reference value in the first period, the control unit does not perform the boiling-up operation, The water heating system according to claim 1 or 2.

6. The control unit performs the boiling-up operation after the first period has elapsed, The water heating system according to claim 5.

7. When there is a scheduled hot water supply after the first period has elapsed, the control unit performs the boiling-up operation in the period from after the first period has elapsed until the scheduled hot water supply time, The water heating system according to claim 5.

8. The control unit performs the boiling-up operation within a predetermined first time after the first period has elapsed, The water heating system according to claim 5.

9. After determining not to perform the boiling operation, the control unit does not perform hot water supply based on a hot water supply instruction during the period from that determination until the end time of the first period. The hot water supply system according to claim 5.

10. When the remaining hot water amount is less than or equal to a third hot water amount that is less than the first hot water amount, the control unit performs the boiling operation. The hot water supply system according to claim 2.

11. When the remaining hot water amount is greater than the third hot water amount and less than or equal to the first hot water amount, the control unit suppresses the boiling operation. The hot water supply system according to claim 10.

12. The control unit determines whether to perform the boiling operation according to a second time period from the time when the remaining hot water amount becomes less than or equal to the first hot water amount until the end time of the first period. The hot water supply system according to claim 2.

13. When the second time is equal to or greater than a predetermined third time, the control unit performs the boiling operation. The hot water supply system according to claim 12.

14. When the second time is less than a predetermined third time, the control unit does not perform the boiling operation. The hot water supply system according to claim 12.

15. The third time is set by the user. The hot water supply system according to claim 13 or 14.

16. The control unit controls the operation of two or more of the hot water supply devices, and when performing the boiling operation with one of the hot water supply devices during the first period, restricts the operation of the other hot water supply devices. The hot water supply system according to claim 1.

17. The control unit sets a power consumption reduction target value to a value equal to or higher than a power consumption reduction level value set based on the demand response request. The hot water supply system according to claim 16.

18. The control unit restricts the number of hot water supply devices that perform the boiling operation during the first period. The hot water supply system according to claim 16 or 17.

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