Hot water system

Abstract

To suppress total power consumed by a plurality of hot water storage type water heaters while suppressing hot water shortage.SOLUTION: In a hot water supply system having control means for controlling a plurality of hot water storage type water heaters installed in a plurality of dwelling houses, the control means comprises total power calculation means for calculating a total value of water heater consumption power being power which is consumed by the plurality of hot water storage type water heaters as total power, and limit means for limiting the water heater consumption power so that the total power in a concentration load time band in which a power load is concentrated becomes less than or equal to a total power allowable value. When the total power reaches the total power allowable vale or larger in the concentration load time band, the limit means sets a heating capacity at a boil operation to a capacity which is the same as the heating capacity in the boil operation when the water heater consumption power is not limited, and controls the water heaters so that a tapping temperature at the boil operation reaches a second tapping temperature which is lower than a first tapping temperature being the tapping temperature at the boil operation when the water heater consumption power is not limited.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to hot water systems. [Background technology]

[0002] Storage-type water heaters are widely used, which are configured to store high-temperature hot water heated by a heat pump unit in a hot water storage tank, and to extract hot water from the hot water storage tank when needed and supply it to a hot water supply terminal. In storage-type water heaters, it is common to store the amount of heat required for hot water supply in a day in the hot water storage tank by performing boiling operation mainly during late-night hours when electricity rates are cheaper.

[0003] There are also cases where storage-type water heaters are installed in each house in an apartment building. Assuming that a storage-type water heater is used in each house in an apartment building, the storage-type water heaters in all houses will perform boiling operation near the end of the night hours (for example, from 11:00 pm to 7:00 am the next morning), and the power demand of the entire apartment building may become high. Patent Document 1 describes a water heating system having two operating modes with different heating capacities that level out the power demand of the entire apartment building. Specifically, this water heating system divides the boiling operation of multiple storage-type water heaters during the night hours into two modes with different heating capacities, and by making the time periods for starting and stopping the boiling operation different, the maximum power consumption of the entire apartment building is reduced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-137200 A Summary of the Invention [Problem to be solved by the invention]

[0005] During the daytime hours excluding late-night hours, power consumption in an average household increases during the nighttime hours after 6 p.m. During this concentrated load period, hot water is consumed for filling and keeping the bathtub warm, showers, etc., and hot water in the hot water storage tank may be insufficient. In this case, the hot water storage type water heater performs additional boiling operation. In Patent Document 1, the timing of the boiling operation is shifted for each household in order to reduce power consumption throughout the entire apartment building, but if the timing of the additional boiling operation during the daytime hours is shifted, there is a risk that the heat storage capacity of the storage type water heater of the household for which the timing is delayed will not be able to recover in time and will run out of hot water.

[0006] The present disclosure has been made to solve the problems described above, and aims to provide a hot water supply system that is advantageous in reducing the total power consumed by multiple storage type water heaters while suppressing the occurrence of hot water shortages. [Means for solving the problem]

[0007] A hot water supply system including a control means for controlling a plurality of hot water storage type hot water heaters installed in a plurality of houses, Each of the plurality of hot water storage type hot water heaters includes a heat pump unit; The control means includes a total power calculation means for calculating the total value of the water heater power consumption, which is the power consumed by each of the plurality of storage type water heaters, as the total power, and a limiting means for limiting the water heater power consumption so that the total power during a concentrated load time period when the power load is concentrated is equal to or less than the total power allowable value. Heat pump unit The heating capacity is set to the same capacity as the heating capacity in boiling operation when power consumption is not limited, and the outlet hot water temperature in the boiling operation is controlled to be a second outlet hot water temperature lower than a first outlet hot water temperature, which is the outlet hot water temperature in the boiling operation when power consumption is not limited. Effect of the Invention

[0008] According to the hot water supply system of the present disclosure, it is possible to reduce the total power consumed by multiple storage type water heaters while preventing hot water shortages in multiple storage type water heaters during concentrated load periods when the load is concentrated. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing the configuration of a storage type hot water heater according to a first embodiment of the present disclosure. [Diagram 2] 1 is a block diagram showing a control configuration of a water heater control device of a storage type water heater according to embodiment 1 of the present disclosure. FIG. [Diagram 3] 1 is a schematic diagram showing a configuration of a hot water supply system according to a first embodiment of the present disclosure. [Figure 4] FIG. 2 is a diagram showing the flow of water and refrigerant during boiling operation of the storage type water heater according to the first embodiment of the present disclosure. [Diagram 5] 4 is a flowchart showing a control operation executed by the hot water supply system according to the first embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Elements common to each figure are given the same reference numerals, and duplicated descriptions will be omitted. In addition, in this embodiment, when describing the calorific value of hot water, the calorific value of hot water may be described in units of the amount of hot water [L] when converted into the calorific value of hot water at a predetermined reference hot water supply temperature. The value of the reference hot water supply temperature is, for example, 42°C. In addition, in this disclosure, expressions such as "water", "hot water", and "hot water and water" are used, but these do not strictly limit the temperature of water, and if there is no particular limit on the temperature, liquid water of any temperature, from low temperature water to high temperature hot water, may be included.

[0011] Embodiment 1 1 is a schematic diagram showing the configuration of a storage type water heater 101 according to the present embodiment 1. The storage type water heater 101 includes a heat pump unit 200 that uses a refrigeration cycle to collect heat from air and heat water, a tank unit 300 having a hot water storage tank 11 that stores the heated hot water, and a remote control 400.

[0012] The heat pump unit 200 has devices such as a compressor 1, a water-refrigerant heat exchanger 2, an expansion valve 3, and an air heat exchanger 4. These devices are connected in a ring shape with piping to form a refrigerant circuit 201 that circulates the refrigerant by the compressor 1. The refrigerant circulating through the refrigerant circuit 201 is preferably a refrigerant capable of producing hot water at high temperatures, such as carbon dioxide, R410A, or propane, but is not limited to these refrigerants.

[0013] The water-refrigerant heat exchanger 2 exchanges heat between water and a refrigerant, and has a water inlet and outlet, and a refrigerant inlet and outlet. Water flowing in from the water inlet is heated by heat exchange with the refrigerant, and flows out from the outlet as hot water with an increased temperature. The air heat exchanger 4 exchanges heat between air and the refrigerant. A fan 5 is attached to the air heat exchanger 4, and takes in outside air and blows it to the air heat exchanger 4.

[0014] The heat pump unit 200 includes an inlet water temperature sensor 13a that detects the temperature of water flowing into the water-refrigerant heat exchanger 2, an outlet hot water temperature sensor 13b that detects the temperature of heated water flowing out from the water-refrigerant heat exchanger 2, and an outside air temperature sensor 13c that detects the outside air temperature around the heat pump unit 200. The outlet hot water temperature sensor 13b detects the hot water temperature (hereinafter referred to as the "outlet hot water temperature") in the vicinity of the outlet of the water-refrigerant heat exchanger 2. The refrigerant circuit 201 also includes a discharge temperature sensor 13d that detects the temperature of the refrigerant discharged from the compressor 1, a suction temperature sensor 13e that detects the temperature of the refrigerant sucked into the compressor 1, and an evaporation temperature sensor 13f that detects the temperature of the refrigerant at the inlet or intermediate position of the air heat exchanger 4.

[0015] The heat pump control device 14 includes a calculation means for executing a program by a microprocessor, a measurement means for collecting detection data of each of the temperature sensors 13a to 13f, a storage means such as a RAM (Random Access Memory) for storing the measurement data and data on the operation state and an EEPROM (Electrically Erasable Programmable Read-Only Memory) for storing the program, a communication means for communicating with a water heater control device 18 described later, and a control means (none of which are shown) for controlling the rotation speed of the compressor 1, the opening degree of the expansion valve 3, the rotation speed of the fan 5, and the like. The heat pump control device 14 controls the heating capacity of the heat pump unit 200 based on the detection values ​​of the temperature sensors 13a to 13f and input information from the water heater control device 18 of the tank unit 300. The water heating means provided in the storage type water heater 101 according to the present disclosure is not limited to the heat pump unit 200. The water heating means may be, for example, an electric heater.

[0016] The tank unit 300 is provided with a hot water storage tank 11, a circulation pump 6a, a reheating pump 6b, a switching valve 7, a switching valve 8, a switching valve 9, a medium temperature water mixing valve 10, a hot water supply mixing valve 15a, and a bath mixing valve 15b. The circulation pump 6a circulates water or heated hot water through a hot water storage circuit 301 (described later) and causes it to flow into the water-refrigerant heat exchanger 2, and constitutes a part of the hot water storage circuit 301. The reheating pump 6b sends hot water from a bathtub (not shown) to the bath heat exchanger 12. The bath heat exchanger 12 uses the hot water supplied from the hot water storage tank 11 to heat the bathtub water on the secondary side.

[0017] The hot water tank 11 stores hot water heated by the heat pump unit 200. The hot water tank 11 is provided with a high-temperature water outlet 11a located at the top of the hot water tank 11, a hot water outlet 11b located at the top of the hot water tank 11, a medium-temperature water return port 11c located at the middle height of the hot water tank 11 and returning to the hot water tank 11 medium-temperature water that has been used for reheating and has returned with a reduced temperature, a medium-temperature water outlet 11d located at the middle height of the hot water tank 11, a low-temperature boiled water return port 11e located at the bottom of the hot water tank 11, a water intake port 11f located at the bottom of the hot water tank 11, and a water supply port 11g located at the lower side of the hot water tank 11.

[0018] The switching valve 7 is an electromagnetically driven four-way valve having four ports A, B, C, and D, and constitutes a switching mechanism that switches the flow path of hot water flowing out of the water-refrigerant heat exchanger 2 between the switching valve 8 and the low-temperature boiling water return port 11e. The switching valve 8 is an electromagnetically driven four-way valve having four ports E, F, G, and H, and constitutes a switching mechanism that causes water flowing in from port E to flow out to either the hot water storage port 11b, the medium-temperature water return port 11c, or the bath heat exchanger 12. The switching valve 9 is an electromagnetically driven three-way valve having three ports I, J, and K, and constitutes a switching mechanism that causes water flowing out of the water intake port 11f of the hot water storage tank 11 or the bath heat exchanger 12 to flow out to the water-refrigerant heat exchanger 2 through the circulation pump 6a. The medium temperature water mixing valve 10 has three ports L, M, and N, mixes water from the medium temperature water outlet 11 d and water from the water supply end 20 , and causes the water to flow out to the hot water supply mixing section 15 .

[0019] The heat pump unit 200 and the tank unit 300 are connected via a heat pump forward pipe 16a, a heat pump return pipe 16k, and electrical wiring (not shown). The water outlet of the water-refrigerant heat exchanger 2 is connected to port A of the switching valve 7 via the heat pump forward pipe 16a. Port B of the switching valve 7 is connected to port E of the switching valve 8 via pipe 16b. Port F of the switching valve 8 is connected to the high-temperature water outlet 11a via pipe 16c and pipe 16d. Port F is connected to the primary-side inlet of the bath heat exchanger 12 via pipe 16c and pipe 16e. The primary-side outlet of the bath heat exchanger 12 is connected to port J of the switching valve 9 via pipe 16f, and is connected to the medium-temperature water outlet 11d of the hot water storage tank 11 via pipe 16g. Port I of the switching valve 9 is connected to the water intake 11f via pipe 16i, and port K is connected to the suction port of the circulation pump 6a via pipe 16j.

[0020] The discharge port of the circulation pump 6a is connected to the inlet of the water-refrigerant heat exchanger 2 via a heat pump return pipe 16k, and is connected to a port C of the switching valve 7 via a pipe 16l. A port D of the switching valve 7 is connected to a low-temperature boiling water return port 11e via a pipe 16m. A port H of the switching valve 8 is connected to the hot water outlet 11b via a pipe 16h and a pipe 16p, and a port G is connected to the medium-temperature water return port 11c via a pipe 16o. A water supply port 11g of the hot water tank 11 is connected to a water supply end 20 via a pipe 16n.

[0021] The hot water storage tank 11 is equipped with a plurality of hot water temperature sensors 13g-13j. The hot water temperature sensors 13g-13j are installed at different height positions on the surface of the hot water storage tank 11, and detect the water temperature in the hot water storage tank 11 at each installation location. The temperature measured by each of the hot water temperature sensors 13g-13j represents the temperature of a partial amount of water of several tens of liters within the range in which the sensor is installed. By detecting the temperature distribution of hot water in the hot water storage tank 11 with these hot water temperature sensors 13g-13j, the amount of hot water remaining in the hot water storage tank 11 is grasped, and this is used to determine operating conditions such as starting and stopping the boiling operation by the heat pump unit 200.

[0022] In addition, the piping of the storage type water heater 101 is provided with a water supply temperature sensor 13k that detects the water temperature supplied from the water supply end 20, a hot water temperature sensor 13l that detects the hot water temperature of the hot water supplied from the hot water supply mixing valve 15a, a hot water supply flow rate sensor 17a that detects the hot water supply flow rate, a bath temperature sensor 13m that detects the temperature of the hot water supplied to the bathtub, and a bath flow rate sensor 17b that detects the flow rate.

[0023] The hot water heater control device 18 is connected to the remote control 400 by wire or wirelessly so as to be able to communicate bidirectionally. The hot water heater control device 18 and the remote control 400 may be able to communicate via a network. The remote control 400 is an example of a user interface. The remote control 400 has a display unit that displays information and an operation unit that can be operated by a user. The remote control 400 may have a touch screen that has the functions of both the display unit and the operation unit. The operation unit of the remote control 400 has a function as an input means that accepts operation input of commands related to the operation and setting values ​​of the hot water storage type hot water heater 101. A person such as a user can remotely operate the hot water storage type hot water heater or perform various settings by operating a switch or the like of the operation unit. The display unit has a function as a notification unit that notifies a person such as a user of information. The remote control 400 in this embodiment has a display unit as a notification unit, but as a modified example, it may have other notification means such as a voice guide device such as a speaker and a microphone. In addition, a mobile information terminal such as a smartphone may be configured to have a function as a user interface like the remote control 400. A configuration may be possible in which a plurality of remote controls 400 are capable of communicating with the water heater control device 18.

[0024] FIG. 2 is a block diagram showing a control configuration of the water heater control device 18 provided in the storage type water heater 101. The water heater control device 18 shown in FIG. 2 is built into the tank unit 300. The water heater control device 18 includes a measurement means 181, a storage means 182, a calculation means 183, a drive means 184, and a communication means 185. The measurement means 181 measures the detection values ​​of the temperature sensors 13g to 13m and the flow rate sensors 17a and 17b. The storage means 182 stores data measured by the measurement means 181, a control program, and data to be used as a control judgment condition. The calculation means 183 calculates the control judgment condition and the like using the data in the storage means 182. The drive means 184 operates a valve, a pump, and the like based on the calculation result of the calculation means 183. The communication means 185 communicates with the heat pump control device 14, the remote control 400, and the central controller 500 to transmit and receive data. Specifically, the communication means 185 communicates with the heat pump control device 14 to collect status monitoring data and transmit control commands to start and stop the heat pump unit 200. The communication means 185 also communicates with the remote control to collect operation command values ​​input to the remote control 400 and transmit data stored in the storage means 182 to the remote control 400. Furthermore, the communication means 185 communicates with the centralized controller 500 to receive commands from the centralized controller 500 and transmit information regarding the operating status of the hot water storage type water heater 101.

[0025] FIG. 3 is a schematic diagram showing a configuration of a hot water supply system according to the first embodiment of the present disclosure. As shown in FIG. 3, the hot water supply system 100 according to the first embodiment includes a central controller 500 and a plurality of storage type hot water heaters 101. The plurality of storage type hot water heaters 101 are provided, for example, for a plurality of households in a facility such as an apartment building. In the example of FIG. 3, the number of houses is three, but the number of houses may be two or four or more. In the following description, the power consumption of the storage type hot water heater 101 may be referred to as "hot water heater power consumption". In addition, the total power consumption of the hot water heaters in the apartment building may be referred to as "total power".

[0026] The centralized controller 500 is connected to the water heater control device 18 of the storage type water heater 101 in each house by wired communication or wireless communication. The centralized controller 500 may be connected to a router in each house via a network. The centralized controller 500 may be installed, for example, within the premises of an apartment building and connected to a network that is a LAN (Local Area Network) of the apartment building. Alternatively, the centralized controller 500 may be installed in a facility outside the premises of the apartment building, such as a management company, and connected to a network that is the Internet.

[0027] The centralized controller 500 includes a communication means 501, a storage means 502, a total power calculation means 503, and a limiting means 504. The communication means 501 connects to the water heater control devices 18 of each house and a power measurement device (not shown) via a network such as a LAN or the Internet to transmit and receive data. For example, each water heater control device 18 transmits to the centralized controller 500 data such as the start and stop times of the boiling operation, the amount of heat stored and the heat dissipation rate of the hot water storage tank 11, the amount of heat supplied to hot water, the amount of heat heated, and the like in addition to the detected values ​​of the temperature sensors 13g to 13m and the detected values ​​of the flow rate sensors 17a and 17b of the hot water storage type hot water heater 101.

[0028] The storage means 502 stores data received from the water heater control device 18 of each residence and a power measuring device (not shown), other calculation data used for each storage type water heater 101, control programs, data used as control judgment conditions, etc. The total power calculation means 503 acquires the water heater power consumption of each residence from the data stored in the storage means 502, and calculates the total power by adding up the water heater power consumption. The limiting means 504 limits the power consumption consumed by the boiling operation of the storage type water heater 101 of each residence based on the value of the total power calculated by the total power calculation means 503.

[0029] In the hot water supply system 100 of this embodiment, the centralized controller 500 cooperates with the heat pump control device 14 and the water heater control device 18 of each residence to achieve a control means for controlling a plurality of storage type water heaters 101 installed in a plurality of residences. In the hot water supply system according to the present disclosure, which control device executes which process is not limited to what is described in this specification. For example, the process described in this specification as being executed by the centralized controller 500 may be executed by the water heater control device 18 or the heat pump control device 14, and the process described in this specification as being executed by the water heater control device 18 or the heat pump control device 14 may be executed by the centralized controller 500.

[0030] Also, instead of the heat pump control device 14 and the water heater control device 18 of each house, for example, each remote control 400 may execute part or all of the processing. In that case, the remote control 400 corresponds to the control device. Also, the control means of the hot water supply system 100 in the present disclosure is not limited to a configuration in which multiple control devices work together, and may be configured by a single control device.

[0031] Next, the operation of the boiling operation of the hot water supply system will be described with reference to Fig. 4. Fig. 4 is an explanatory diagram of the operation during the boiling operation. The boiling operation for storing hot water in the hot water storage tank 11 is an operation in which the refrigerant circuit 201 and the hot water storage circuit 301 are operated, low-temperature water flowing out from the water intake 11f is heated by the refrigerant circuit 201, and high-temperature water flowing out from the water-refrigerant heat exchanger 2 is caused to flow into the upper part of the hot water storage tank 11 from the hot water storage port 11b via the B port of the switching valve 7 and the H port of the switching valve 8. In this boiling operation, hot water is stored in the hot water storage tank 11 while maintaining a temperature stratification in which the upper part is high-temperature water and the lower part is low-temperature water.

[0032] Next, the hot water temperature control during the boiling operation will be described. In this temperature control, the heat pump control device 14 feedback controls the rotation speed of the circulation pump 6a so that the hot water outlet temperature of the water-refrigerant heat exchanger 2 detected by the outlet temperature sensor 13b becomes equal to a predetermined target hot water outlet temperature. In the boiling operation, heat is stored in a state where the target hot water outlet temperature is set to a predetermined target hot water storage outlet temperature. The target hot water outlet temperature is set based on the operation of the remote control 400, or is set so that a required amount of heat calculated from the past hot water usage amount can be secured. Alternatively, the target hot water outlet temperature is changed according to a command value set by the limiting means 504 of the central controller 500, which will be described later. The target hot water outlet temperature may be set by any of the heat pump control device 14, the water heater control device 18, and the remote control 400.

[0033] The determination of whether or not the boiling is completed is made, for example, based on whether or not the temperature detected by the hot water temperature sensor 13j or the inlet water temperature sensor 13a, which is provided at the bottom of the hot water tank 11 among the multiple hot water temperature sensors 13g-13j, is equal to or higher than a preset boiling stop temperature, or whether or not the amount of boiled heat has reached a target heat storage amount. When the boiling is completed, the water heater control device 18 issues a boiling operation stop command to the heat pump control device 14. Upon receiving this command, the heat pump control device 14 stops the heat pump unit 200 and the circulation pump 6a, and ends the boiling operation.

[0034] In the hot water supply system 100 according to this embodiment, when the boiling operation of the multiple storage type hot water heaters 101 is performed during a concentrated load time period when the power load is concentrated, the centralized controller 500 performs power limit control to limit the total power so as not to exceed a total power allowable value which is a threshold value. Fig. 5 is a flow chart for explaining the control operation of the power limit control. The power limit control will be explained below with reference to Fig. 5.

[0035] In the control of Fig. 5, in step S1, the target hot water outlet temperature is set to a first hot water outlet temperature, and boiling operation is started. The first hot water outlet temperature is a temperature that is set in normal boiling operation when power consumption restriction is not required.

[0036] Next, in step S2, a total power allowable value is set, which is a threshold value for the total power available in the entire hot water supply system 100. For example, when electricity charges are composed of a basic charge determined according to the maximum power consumption and an energy charge proportional to the amount of power used, it is desirable to keep the maximum power consumption low. The total power allowable value is determined, for example, according to the power obtained by subtracting from the maximum power consumption the total value of the power consumption of devices other than the storage type hot water heater 101 used in each residence during the concentrated load period. The centralized controller 500 has a function as an allowable value setting means for setting the total power allowable value, and may calculate the total power allowable value each time. Alternatively, the total power allowable value may be a value stored in advance. Alternatively, it may be possible for a user or the like to directly input it.

[0037] Next, in step S3, it is determined whether the total power, which is the total value of the current hot water heater power consumption of each house calculated by the total power calculation means 503, is greater than the total power allowable value set in step S2. If it is determined that the total power is not greater than the total power allowable value, the process returns to step S3. Thereafter, the determination process of step S3 is repeatedly executed at regular control intervals until it is determined that the total power is greater than the total power allowable value.

[0038] On the other hand, if it is determined in step S3 that the total power is greater than the total power allowable value, the process proceeds to S4. In step S4, the target hot water outlet temperature of the hot water boiling operation of the storage type hot water heater 101 currently performing the boiling operation is changed to the second hot water outlet temperature. In each storage type hot water heater 101, the boiling operation is performed at the second hot water outlet temperature. The second hot water outlet temperature may be a value lower than the first hot water outlet temperature, set in advance, and stored in the storage means 502 of the centralized controller 500 or the storage means 182 of the hot water heater control device 18. Alternatively, the centralized controller 500 may have a function as a hot water outlet temperature setting means for setting the second hot water outlet temperature, and may calculate and set the second hot water outlet temperature each time. For example, the centralized controller 500 may be configured to calculate the second hot water outlet temperature based on, for example, the total power allowable value and the number of storage type hot water heaters 101 currently performing the boiling operation.

[0039] In step S4, when the target hot water outlet temperature is changed, the heating capacity of heat pump unit 200 is maintained at the current capacity and is not changed. In other words, the heating capacity of heat pump unit 200 is maintained at the heating capacity in normal boiling operation when the total power is not limited. After step S4, the current process ends.

[0040] As described above, according to hot water supply system 100 of the present embodiment, the target hot water outlet temperature is changed based on whether the total power exceeds the total power allowable value. This makes it possible to effectively suppress the total power while preventing hot water shortages.

[0041] In the present embodiment, a case has been described in which when the total power of hot water supply system 100 exceeds the total power allowable value, the target hot water outlet temperature of all hot water storage type hot water heaters 101 is uniformly lowered to the second hot water outlet temperature to suppress the total power. This makes it possible to reduce the total power consumed in the apartment building. However, the power limit control in hot water supply system 100 according to the present disclosure is not limited to this.

[0042] For example, if it is determined that the total power is greater than the total power allowable value, the centralized controller 500 may select one storage type water heater from among the storage type water heaters 101 currently in boiling operation, and transmit a command to the water heater control device 18 of the selected storage type water heater 101 to set the target hot water outlet temperature to the second hot water outlet temperature, thereby lowering only the hot water outlet temperature of the selected storage type water heater 101. In this case, the process of sequentially selecting one storage type water heater 101 from the storage type water heaters 101 currently in boiling operation and lowering the target hot water outlet temperature of the selected storage type water heater 101 may be repeatedly performed until the total power becomes equal to or less than the total power allowable value.

[0043] Alternatively, if it is determined that the total power is greater than the total power allowable value, a number of storage type water heaters 101 that can reduce the total power to below the total power allowable value can be selected, and the target water outlet temperature for the selected storage type water heaters 101 can be set to the second water outlet temperature.

[0044] Furthermore, hot water supply system 100 may be configured to change the target hot water outlet temperature to a third hot water outlet temperature that is lower than the second hot water outlet temperature if the temperature at the top of hot water storage tank 11 is equal to or higher than a predetermined temperature, for example. Specifically, the third hot water outlet temperature is a temperature that is set so that the temperature of hot water storage tank 11 is equal to or higher than 60°C, which is the temperature at which Legionella bacteria die. In other words, if hot water at a temperature of 60°C or higher is stored in the top of hot water storage tank 11, the third hot water outlet temperature may be set to less than 60°C. This makes it possible to more effectively reduce the total power consumption of hot water supply system 100.

[0045] In the present embodiment, a case has been described in which, when performing boiling operation with the second or third hot water outlet temperature as the target hot water outlet temperature, boiling operation is performed with a heating capacity equivalent to the heating capacity when the target hot water outlet temperature is the first hot water outlet temperature. This makes it possible to prevent hot water shortages in each hot water storage type hot water heater 101. However, hot water supply system 100 may be configured to perform a combination of controls to reduce heating capacity within a range that can prevent hot water shortages when the total power exceeds the total power allowable value.

[0046] Furthermore, in this embodiment, when a certain storage type water heater 101 performs a boiling operation with the second hot water outlet temperature or the third hot water outlet temperature as the target hot water outlet temperature, the display unit of the remote controller 400 corresponding to that storage type water heater 101 may be configured to display that the boiling operation is being performed at the second hot water outlet temperature or the third hot water outlet temperature. This allows the user to recognize that a boiling operation with reduced power is being performed.

[0047] Furthermore, the hot water supply system 100 may be configured so that the user can input a refusal setting, which is a command not to perform the boiling operation at the second hot water outlet temperature or the third hot water outlet temperature, from the operation unit of each remote control 400. In this case, the fact that the refusal setting has been set may be displayed on a display unit of the remote control 400 or the like. This allows high-temperature hot water to be stored in the tank unit 300, reducing the user's concern about running out of hot water, and notifying the user that the refusal setting may increase the total amount of power consumed. [Explanation of symbols]

[0048] 1 compressor, 2 water-refrigerant heat exchanger, 3 expansion valve, 4 air heat exchanger, 5 fan, 6a circulation pump, 6b reheating pump, 7-9 switching valve, 10 medium temperature water mixing valve, 11 hot water storage tank, 11a high temperature water outlet, 11b hot water storage outlet, 11c medium temperature water return outlet, 11d medium temperature water outlet, 11e low temperature boiling water return outlet, 11f water intake, 11g water supply inlet, 12 heat exchanger, 13 hot water storage temperature sensor, 13a inlet water temperature sensor, 13b outlet hot water temperature sensor, 13c outside air temperature sensor, 13d discharge temperature sensor, 13e suction temperature sensor, 13f evaporation temperature sensor, 13j hot water storage temperature sensor, 13k water supply temperature sensor, 13l hot water temperature sensor, 13m temperature sensor, 14 heat pump control device, 15 hot water mixing section, 15a hot water mixing valve, 15b bath mixing valve, 16a heat pump forward piping, 16k heat pump return piping, 16b-16p piping, 17a hot water flow rate sensor, 17b bath flow rate sensor, 18 hot water heater control device, 20 water supply end, 100 hot water system, 101 hot water storage type hot water heater, 181 measuring means, 182 memory means, 183 calculation means, 184 driving means, 185 communication means, 200 heat pump unit, 201 refrigerant circuit, 300 tank unit, 301 hot water storage circuit, 400 remote control, 500 central controller, 501 communication means, 502 storage means, 503 total power calculation means, 504 limiting means, A to L ports

Claims

1. A hot water supply system including a control means for controlling a plurality of hot water storage type hot water heaters installed in a plurality of houses, Each of the plurality of hot water storage type hot water heaters includes a heat pump unit, The control means a total power calculation means for calculating a total value of water heater power consumption, which is the power consumed by each of the plurality of hot water storage type water heaters, as a total power; a limiting means for limiting the power consumption of the water heater so that the total power during a concentrated load time period during which the power load is concentrated is equal to or less than a total power allowable value; Equipped with The limiting means is If the total power during the concentrated load period becomes greater than the total power allowable value, The heating capacity of the heat pump unit during boiling operation is set to the same capacity as the heating capacity during boiling operation when the water heater power consumption is not limited, and The hot water outlet temperature during the boiling operation is controlled to be a second hot water outlet temperature that is lower than a first hot water outlet temperature, which is the hot water outlet temperature during the boiling operation when the power consumption of the water heater is not limited. A hot water supply system comprising:

2. The limiting means is a control for sequentially selecting one of the storage type hot water heaters in the boiling operation and limiting the outlet temperature of the selected storage type hot water heater to the second outlet temperature; Repeatedly executing the process until the total power becomes equal to or less than the total power allowable value. The hot water supply system according to claim 1 .

3. The limiting means is selecting a number of storage type hot water heaters that can make the total power equal to or less than the total power allowable value from among the storage type hot water heaters that are in the boiling operation; executing control for limiting the outlet hot water temperature of the selected storage type hot water heater to the second outlet hot water temperature; The hot water supply system according to claim 1 .

4. The limiting means includes an allowable value setting means for setting the value of the total allowable power value, The hot water supply system according to any one of claims 1 to 3, further comprising:

5. The limiting means includes an outlet heated water temperature setting means for setting a value of the second outlet heated water temperature, The hot water supply system according to any one of claims 1 to 4, further comprising:

6. Each of the plurality of hot water storage type hot water heaters includes a notification means for notifying information regarding an operating state of each of the plurality of hot water storage type hot water heaters, The control means The information notified by each of the notification means is controllable, and The notification means of the hot water storage type hot water heater, in which the outlet temperature is limited to the second outlet temperature, notifies that a boiling operation is being performed at the second outlet temperature. The hot water supply system according to any one of claims 1 to 5.

7. Each of the plurality of hot water storage type hot water heaters includes an input means capable of receiving an input of a refusal setting which is a setting for refusing to execute a control in which the outlet hot water temperature is limited to the second outlet hot water temperature, The limiting means is When the input means of one of the plurality of hot water storage type hot water heaters receives the input of the refusal setting, the limiting means does not execute control of the one hot water storage type hot water heater to limit the outlet hot water temperature to the second outlet hot water temperature. The hot water supply system according to any one of claims 1 to 6.

8. Each of the plurality of hot water storage type hot water heaters further includes a notification means for notifying information regarding an operating state of each of the plurality of hot water storage type hot water heaters, The control means The information notified by the notifying means is controllable, and When the input means of the one hot water storage type hot water heater accepts the input of the refusal setting, the notification means of the one hot water storage type hot water heater notifies that the boiling operation at the second hot water outlet temperature is refused. The hot water supply system according to claim 7 .

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