Hot water supply method, system and program

Abstract

To realize hot water supply for enhancing utilization efficiency of heat storage in a hot water storage tank and corresponding to hot water supply demand.SOLUTION: A hot water supply method includes combinedly using first hot water supply means (HP water heater 4) of storing hot water heated by a heat pump (HP unit 10) in a hot water storage tank (hot water storage tank unit 12), and delivering hot water from the hot water storage tank, and second hot water supply means (multiple water heater 6) of heating supply water by heat sources (gas water heaters 24-1, 24-2) excluding the heat pump and delivering hot water. The method includes a step of selecting a single delivery mode of determining a hot water supply capacity by a heat storage state of the hot water storage tank based on a temperature of hot water at least at a predetermined height position in the hot water storage tank, detected by temperature detection means (temperature sensor 22) by a control section (HP control section 14) of the first hot water supply means, and delivering by any one of the first hot water supply means and the second hot water supply means based on the temperature, or the temperature and a total delivery amount of hot water supply demand, or a hybrid delivery mode of combinedly using the first hot water supply means and the second hot water supply means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a hot water supply method, system, and program that uses a hot water supply means that includes a heat pump or a hot water storage tank as a heat source, in combination with a hot water supply means that includes a heat source other than a heat pump. [Background technology]

[0002] Hybrid hot water supply systems that use a heat pump as a heat source and a hot water storage tank in combination with a hot water supply means that includes a heat source other than a heat pump are already known, and multi-hot water supply systems that use multiple gas water heaters as a heat source means other than a heat pump are also known.

[0003] It is known that this hybrid hot water supply system is provided with an auxiliary hot water supply means as a gas-fired or oil-fired heat source directly or indirectly in the hot water supply path from the hot water storage tank to the hot water supply load (for example, Patent Document 1).

[0004] In such a hot water supply system, when the hot water supply set temperature is changed downward during heating operation of the auxiliary heat source unit, it is known that the target temperature is lowered so that the difference temperature between the hot water supply set temperature before the change downward and the target temperature is maintained even after the change downward (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-349202 A [Patent Document 2] Patent Publication No. 2023-75435 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in a hybrid hot water supply system that combines a hot water supply means including a hot water storage tank with a heat pump as a heat source, and a hot water supply means including a heat source other than a heat pump (or a multi-hot water supply system), for example, an HP water heater including a heat pump (hereinafter referred to as "HP") and a hot water storage tank, and a GB water heater including a heat source other than a heat pump, for example a gas boiler (hereinafter referred to as "GB"), are provided, and it is possible to supply hot water by selecting either the HP water heater or the GB water heater alone, or by selecting the combined operation of the HP water heater and the GB water heater.

[0007] HP water heaters are equipped with a hot water storage tank, and store the hot water generated by the HP in the tank unit to store heat. Discharging the hot water from the hot water storage tank is beneficial because it utilizes the stored heat. If it is not possible to add heat storage to the hot water storage tank, or even if it is possible to add more, if the amount of heat stored in the tank is greater than the amount of heat stored, the temperature of the hot water being discharged will drop. Also, even when HP water heaters and GB water heaters are operated in parallel, if the temperature of the hot water being discharged is set in the tank unit to exceed the hot water supply capacity of the heat storage, the HP water heater will not be able to supply hot water as requested, and the temperature of the hot water being discharged from the hybrid hot water system will drop.

[0008] On the other hand, there is a problem in that if the burden share of the GB water heater is made too high, the significance of having an HP water heater installed in addition will be lost.

[0009] The inventors of the present disclosure have discovered that achieving balanced utilization of the HP water heater and the GB water heater depending on the heat storage state and total hot water supply volume is beneficial in increasing the utilization efficiency of the heat stored in the hot water tank.

[0010] Therefore, an object of the present disclosure is to increase the efficiency of utilizing the heat stored in the hot water storage tank and realize hot water supply that meets hot water demand. [Means for solving the problem]

[0011] In order to achieve the above-mentioned object, according to one aspect of the hot water supply method disclosed herein, there is provided a hot water supply method that uses in combination a first hot water supply means that stores hot water heated by a heat pump in a hot water storage tank and supplies hot water from this hot water storage tank, and a second hot water supply means that heats water using a heat source other than the heat pump and supplies hot water, and the method includes a step in which a control unit of the first hot water supply means determines the hot water supply capacity due to the heat storage state of the hot water storage tank based on the temperature of the hot water at least at a predetermined height position in the hot water storage tank detected by a temperature detection means, and selects a single hot water supply mode in which either the first hot water supply means or the second hot water supply means supplies hot water based on the temperature, or the temperature and the total hot water supply amount requested, or a hybrid hot water supply mode in which the first hot water supply means and the second hot water supply means are used in combination.

[0012] In the above hot water supply method, the control unit includes a step of selecting the single hot water supply mode in which hot water is supplied only by the second hot water supply means if the temperature is below a threshold value, or selecting the single hot water supply mode in which hot water is supplied only by the first hot water supply means if the temperature is higher than the threshold value and the total hot water supply amount is below a predetermined value. In the above hot water supply method, the control unit includes a step of selecting either a first hybrid hot water supply mode in which, when the temperature is higher than the threshold value but the total hot water supply volume is greater than the flow rate threshold, either the first hybrid hot water supply mode adjusts either the hot water supply volume or the hot water supply temperature from the first hot water supply means or both within a predetermined range and supplies hot water in conjunction with the second hot water supply means, or a second hybrid hot water supply mode in which, when the temperature is higher than the threshold value but the temperature in the hot water storage tank is below the requested hot water supply temperature, the control unit suppresses the hot water supply volume from the first hot water supply means and adjusts the hot water supply temperature, and supplies hot water in conjunction with the second hot water supply means. In the above hot water supply method, if the control unit defines the amount of hot water discharged from the first hot water supply means as Q1, the hot water discharge temperature from the first hot water supply means as T1, the amount of hot water discharged from the second hot water supply means as Q2, the hot water discharge temperature from the second hot water supply means as T2, and the total amount of hot water discharged as Q, then the mixed temperature T obtained from this total amount of hot water discharged Q is: T = (Q1 × T1 + Q2 × T2) ÷ Q and determining the value by

[0013] In order to achieve the above-mentioned object, according to one aspect of the hot water supply system disclosed herein, the hot water supply system uses a first hot water supply means that stores hot water heated by a heat pump in a hot water storage tank and supplies hot water from this hot water storage tank, and a single or multiple second hot water supply means that heat water using a heat source other than the heat pump and supply hot water, and is equipped with a temperature detection means that detects the temperature of the hot water at a predetermined height position in the hot water storage tank, a flow rate monitoring means that monitors the total hot water output volume required for hot water supply, and a control means that determines the hot water supply capacity due to the heat storage state of the hot water storage tank based on the detected temperature in the hot water storage tank, and selects a single hot water output mode in which either the first hot water supply means or the second hot water supply means supplies hot water based on the temperature, or the temperature and the total hot water output volume, or a hybrid hot water output mode in which the first hot water supply means and the second hot water supply means are used in combination.

[0014] In the above-mentioned hot water supply system, the control means selects the single hot water supply mode in which hot water is supplied only by the second hot water supply means if the temperature is below a threshold value, or selects the single hot water supply mode in which hot water is supplied only by the first hot water supply means if the temperature is higher than the threshold value and the total hot water supply amount is below a predetermined value. In the above hot water supply system, when the temperature is higher than the threshold value but the total hot water output volume is greater than the flow rate threshold, the control means selects either a first hybrid hot water output mode in which either one or both of the hot water output volume and the hot water output temperature from the first hot water supply means are adjusted within a predetermined range and used in conjunction with the second hot water supply means to output hot water, or a second hybrid hot water output mode in which, when the temperature is higher than the threshold value but the temperature in the hot water storage tank is below the required hot water supply temperature, the control means selects either a first hybrid hot water output mode in which either one or both of the hot water output volume and the hot water output temperature from the first hot water supply means are adjusted and hot water is output in conjunction with the second hot water supply means to output hot water, In the above-mentioned hot water supply system, while the hybrid hot water supply mode is being executed, the control means controls the mixed temperature obtained by the hot water outlet temperature from the first hot water supply means calculated from the hot water outlet amount of the first hot water supply means and the temperature of hot water at a predetermined height position in the hot water storage tank, and the hot water outlet temperature from the second hot water supply means calculated from the hot water outlet amount of the second hot water supply means, to be the same as the hot water outlet set temperature or to a certain range including that same value.

[0015] In order to achieve the above-mentioned object, according to one aspect of the program of the present disclosure, there is provided a computer program for a hot water supply system that uses a first hot water supply means that stores hot water heated by a heat pump in a hot water storage tank and supplies hot water from this hot water storage tank, and a single or multiple second hot water supply means that heat water using a heat source other than the heat pump and supply hot water, and causes the computer to execute a function of determining the hot water supply capacity based on the heat storage state of the hot water storage tank based on the temperature of the hot water at least at a predetermined height position in the hot water storage tank detected by a temperature detection means, and selecting a single hot water supply mode in which either the first hot water supply means or the second hot water supply means supplies hot water based on the temperature, or the temperature and the total hot water supply amount requested, or a hybrid hot water supply mode in which the first hot water supply means and the second hot water supply means are used together.

[0016] In the above program, the computer is caused to execute a function of selecting the single hot water supply mode in which hot water is supplied only by the second hot water supply means if the temperature is below a threshold value, or selecting the single hot water supply mode in which hot water is supplied only by the first hot water supply means if the temperature is higher than the threshold value and the total hot water supply amount is below a predetermined value. In the above program, the computer is caused to execute a function of selecting either a first hybrid hot water outlet mode in which, when the temperature is higher than the threshold value but the total hot water outlet volume is greater than the flow rate threshold, either one or both of the hot water outlet volume and hot water outlet temperature from the first hot water supply means are adjusted within a predetermined range and hot water is supplied in conjunction with the second hot water supply means, or a second hybrid hot water outlet mode in which, when the temperature is higher than the threshold value but the temperature in the hot water storage tank is below the required hot water supply temperature, the hot water outlet volume from the first hot water supply means is suppressed and the hot water outlet temperature is adjusted, and hot water is supplied in conjunction with the second hot water supply means. In the above program, during execution of the hybrid hot water outlet mode, the computer is caused to execute a function of controlling the mixed temperature obtained by the hot water outlet temperature from the first hot water supply means calculated from the hot water outlet amount of the first hot water supply means and the temperature of the hot water at a predetermined height position in the hot water storage tank, and the hot water outlet temperature from the second hot water supply means calculated from the hot water outlet amount of the second hot water supply means, to be the same as the hot water outlet set temperature or to a certain range including the same value. Effect of the Invention

[0017] According to the present invention, any one of the following effects can be obtained. (1) By improving the utilization rate of the thermal storage in the hot water tank, the hot water supply efficiency can be improved. (2) Based on the thermal storage status of the hot water storage tank and the total amount of hot water required, the operating modes of the HP water heater and GB water heater can be set to prioritize the use of thermal storage, thereby making it possible to provide hot water in response to hot water demand while making effective use of the thermal storage. (3) In response to changes in the heat storage state of the hot water storage tank, in an operating mode in which the HP water heater and the GB water heater are used together, the amount of hot water supplied from the HP water heater is reduced and the hot water is controlled to be discharged at a higher temperature, thereby making effective use of the heat stored in the hot water storage tank. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing a hot water supply system according to an embodiment. [Diagram 2] 2 is a diagram showing the configuration and linking functions of a control unit of the hot water supply system. FIG. [Diagram 3] 11A to 11C are diagrams illustrating examples of hot water supply states in each hot water supply mode. [Figure 4] 11A to 11C are diagrams illustrating examples of hot water supply states in each hot water supply mode. [Diagram 5] 10 is a flowchart showing an example of hot water supply control according to a hot water supply mode setting. [Figure 6] FIG. 11 is a diagram showing an example of a hot water supply control table. [Figure 7] 11 is a time chart showing an example of a state of the second hybrid hot water discharge mode. [Figure 8] 11 is a time chart showing an example of a state of the second hybrid hot water discharge mode. [Figure 9] 10 is a flowchart showing an example of hot water supply control in a hybrid hot water supply mode. [Figure 10] 10 is a flowchart showing an example of hot water supply control in a hybrid hot water supply mode according to an embodiment. [Figure 11] It is a diagram showing an example of a calculation process for the optimum values of the flow rate and the hot water outlet temperature according to the embodiment.

Mode for Carrying Out the Invention

[0019] 〔One Embodiment〕 FIG. 1 shows a hot water supply system according to an embodiment of the present disclosure. The configuration shown in FIG. 1 is an example, and the present disclosure is not limited to the configuration of FIG. 1.

[0020] This hot water supply system 2 includes, for example, as shown in FIG. 1, a heat pump (HP) water heater 4 (hereinafter referred to as "HP water heater 4"), a multi water heater 6 including two or more gas water heaters, a remote control device 8 (hereinafter abbreviated as "remote control 8"), etc., and constitutes, for example, a commercial multi hybrid hot water supply system suitable for commercial use in medium to large scale facilities such as hotels, schools, and hospitals.

[0021] <HP water heater 4> The HP water heater 4 is an example of the first hot water supply means of the present disclosure that uses a heat pump as a heat source and includes a hot water storage tank. This HP water heater 4 includes a heat pump unit 10 (hereinafter simply referred to as "HP unit 10"), a hot water storage tank unit 12 (hereinafter simply referred to as "tank unit 12"), and an HP control unit 14.

[0022] The HP unit 10 and the tank unit 12 are provided with a circulation path 16, and water is supplied from the lower layer part of the tank unit 12 to the HP unit 10, and hot water HW is supplied from the HP unit 10 to the upper layer part of the tank unit 12.

[0023] A water supply circuit 18 and a hot water supply circuit 20 are connected to the tank unit 12. During hot water supply, the tank unit 12 supplies hot water HW from the upper layer part of the tank unit 12 to the hot water supply circuit 20 by supplying water W to the lower layer part of the tank unit 12 through the water supply circuit 18. Tap water such as city water is used as the water supply W to the water supply circuit 18.

[0024] The HP unit 10 includes a heat pump circuit as a heat source. The heat pump circuit uses, for example, CO 2 The heat radiation from the condenser is used to exchange heat between the condenser and the supply water. In this HP water heater 4, the supply water W or low-temperature hot water HW taken out from the lower part of the tank unit 12 is heated by heat exchange with the heat radiation from the condenser, and the hot water HW heated by this heat exchange is returned to the upper part of the tank unit 12. Therefore, the tank unit 12 stores heat in a so-called temperature stratified state in which the upper part is high temperature and the lower part is low temperature. The tank unit 12 is provided with a temperature sensor 22 at least at a predetermined position on the upper side, and detects the heat storage temperature of the hot water HW stored inside. The tank unit 12 may also be provided with a plurality of temperature sensors installed at different heights, for example, to monitor the stratified state of the hot water inside.

[0025] The HP control unit 14 is an example of a control unit of the present disclosure, and constitutes a master control unit for the multi-water heater 6, and performs heat storage control of the HP water heater 4 included in the hot water heating system 2, hot water output control of the HP water heater 4, and coordinated control between the HP water heater 4 and the multi-water heater 6.

[0026] HP control unit 14 is composed of a computer equipped with a communication function, and is composed of a processing unit, a memory unit, an input / output unit, etc. The processing unit executes an OS (Operating System) stored in the memory unit and the hot water supply control program of the present disclosure, etc., to acquire input information from remote control 8 and heat storage information such as the temperature detected by temperature sensor 22, calculate the outlet hot water temperature, perform hot water supply control described below, and control cooperation with multi-hot water heater 6. The memory unit stores the OS and the hot water supply control program. This hot water supply control program includes a database that stores temperature information such as heat storage temperature, outlet hot water temperature, and set temperature, flow rate information of hot water HW and supply water W, and calculation result information of the mixed temperature.

[0027] The heat storage control of the HP water heater 4 monitors the heat storage temperature of the tank unit 12 by acquiring temperature information from a temperature sensor 22 arranged in the upper part of the tank unit 12, acquires flow rate information from a flow rate sensor 25 arranged on the hot water outlet side of the tank unit 12, and performs heat storage control by the hot water of the tank unit 12. The HP water heater 4 also detects the flow rate of the water supply W flowing through the water supply circuit 18 with a flow rate sensor 23 to grasp the total hot water output required for the hot water supply system 2, and determines the hot water supply capacity according to the heat storage state of the tank unit 12 to perform hot water supply control. Alternatively, the HP control unit 14 may calculate the total hot water output of the hot water supply system 2 by summing up the hot water output from the HP water heater 4 detected by the flow rate sensor 25 and the flow rate detected by the flow rate sensors 52-1 and 52-2 (FIG. 2) installed in the gas water heaters 24-1 and 24-2. The HP control unit 14 may then perform hot water supply control based on the calculated total hot water output and the hot water supply capacity according to the heat storage state of the tank unit 12. The amount of hot water discharged in this hot water supply control is determined by the flow rate of hot water discharged from the HP water heater 4 or the multi-water heater 6, hot water flowing in the circuit, and other hot water flowing to the hot water supply load.

[0028] The coordinated control by the HP water heater 4 and the multi water heater 6 is performed with the HP water heater 4 as the master water heater and the multi water heater 6 as the slave water heater. This coordinated control includes control of hot water output by operating either the HP water heater 4 or the multi water heater 6 alone (single mode), and control of hot water output by operating the HP water heater 4 and the multi water heater 6 together (combined mode).

[0029] In this control, if the heat storage temperature of tank unit 12 is equal to or higher than a predetermined value and the amount of hot water output from HP water heater 4 is equal to or lower than a predetermined value, the HP water heater 4 independent mode is selected. If the heat storage temperature of tank unit 12 is lower than a predetermined value, the multi water heater 6 independent mode is selected. Also, if the heat storage temperature of tank unit 12 is equal to or higher than a predetermined value and the amount of hot water output from HP water heater 4 exceeds a predetermined value, the HP water heater 4 and multi water heater 6 combined mode is selected.

[0030] The combined mode of HP water heater 4 and multi water heater 6 includes processes such as monitoring the heat storage temperature of tank unit 12, monitoring the regulated flow rate of HP water heater 4, calculating the mixed temperature based on the outlet temperatures of HP water heater 4 and multi water heater 6, monitoring the mixed temperature using the outlet target temperature (set temperature) set in remote control 8 as the reference value, controlling the outlet amount of HP water heater 4 and multi water heater 6, and controlling the outlet temperature of HP water heater 4.

[0031] <Multi-water heater 6> The multi-water heater 6 is an example of the second hot water supply means of the present disclosure that uses a heat source other than a heat pump. The multi-water heater 6 is composed of, for example, a pair of gas water heaters 24-1, 24-2. These gas water heaters 24-1, 24-2 are equipped with hot water supply control units 26-1, 26-2, which perform hot water supply control based on the hot water supply flow rate and the set temperature. In the multi-water heater 6, for example, the hot water supply control unit 26-1 is connected to the HP control unit 14 of the HP water heater 4 and is also connected to the hot water supply control unit 26-2, and the HP water heater 4 is set as the parent unit and the gas water heaters 24-1, 24-2 as child units. The multi-water heater 6 performs hot water supply processing by the gas water heaters 24-1, 24-2 according to instructions from the HP control unit 14, which is the control means of the parent unit. Furthermore, multi-water heater 6 may be constituted, for example, by gas water heater 24-1 alone, or may constitute a multi-water heater system in which two or more gas water heaters 24-1, 24-2, . . . are provided in an annex.

[0032] Each gas water heater 24-1, 24-2 heats water using, for example, the heat of gas combustion as a heat source. The same or different gas water heaters can be used for each gas water heater 24-1, 24-2, and the hot water output of the multi-water heater 6 is shared between the gas water heaters 24-1, 24-2. That is, when the multi-water heater 6 is operated independently or when it supplies hot water in conjunction with the HP water heater 4, it supplies hot water using only one of the gas water heaters 24-1, 24-2 depending on the hot water supply demand, or both are connected to supply hot water.

[0033] Hot water supply control units 26-1, 26-2, together with HP control unit 14, are an example of a control unit of the present disclosure, and function as a slave control unit to HP control unit 14. These hot water supply control units 26-1, 26-2 are configured by computers equipped with communication functions, similar to HP control unit 14, and include a processing unit, a storage unit, an input / output unit, etc.

[0034] Based on hot water discharge control instructed by HP control unit 14 set as the parent unit of the hot water supply means, multi-water heater 6 performs hot water discharge control of each gas water heater 24-1, 24-2, and coordinated control linking gas water heaters 24-1, 24-2. This hot water discharge control includes control of the discharge temperature and amount of hot water discharged from each gas water heater 24-1, 24-2. The coordinated control also includes control such as selecting gas water heater 24-1 if the amount of hot water discharged shared by multi-water heater 6 among hot water supply requests to hot water supply system 2 is less than the hot water discharge capacity of gas water heater 24-1, and selecting gas water heater 24-2 to share the excess amount of hot water discharge if it exceeds the hot water discharge capacity of gas water heater 24-1.

[0035] <Remote Control 8> Remote control 8 is connected in a state enabling transmission and reception of control information with HP control unit 14, which is the master control unit, and is used to remotely control HP control unit 14 and hot water supply control units 26-1, 26-2. Remote control 8 is equipped with a computer, which communicates with HP control unit 14, and performs startup control of hot water supply control units 26-1, 26-2 via HP control unit 14, and sets the hot water supply target temperature (set temperature) of hot water supply system 2. Remote control 8 may also set the hot water outlet temperature and amount of hot water outlet for HP control unit 14 and / or hot water supply control units 26-1, 26-2.

[0036] <Control function of hot water supply system 2> Fig. 2 shows the configuration and interlocking functions of the control unit of the hot water supply system. The configuration shown in Fig. 2 is one example. The HP control unit 14 is made up of, for example, a processor 30, a memory unit 32, a communication unit 34, and an input / output unit 36. The processor 30 executes arithmetic processing of the OS and the hot water supply control program stored in the memory unit 32, and thereby functions as a processing unit of the hot water supply system 2. The memory unit 32 functions as a storage unit that stores, for example, programs and detection values ​​of the temperature sensor 22 and the flow rate sensors 23 and 25, and also functions as a work area for the processor 30 to execute arithmetic processing. The communication unit 34 is an example of a functional unit that sends and receives information and control instructions between the remote control 8 and the hot water supply control units 26-1 and 26-2, and may be capable of communication processing via wired or wireless means or other means such as near-field infrared communication. The input / output unit 36 ​​is an example of an interface that enables the transmission of control instructions or the reception of detection information between each functional unit of the HP water heater 4. The input / output unit 36 ​​receives detection information such as the detected temperature in the tank unit 12 from the temperature sensor 22 and the amount of water supplied and the amount of hot water discharged from the flow sensors 23, 25. The input / output unit 36 ​​also outputs instructions for heat storage operation generated by a processing unit such as the processor 30 to the HP unit 10 or a pump installed on the circulation path 16 (not shown).

[0037] The hot water supply control units 26-1 and 26-2 are respectively composed of processors 38-1 and 38-2, memory units 40-1 and 40-2, communication units 42-1 and 42-2, and input / output units 44-1 and 44-2, for example. The processors 38-1 and 38-2 execute the arithmetic processing of the OS and the hot water supply control program stored in the memory units 40-1 and 40-2. The memory units 40-1, 40-2 function as storage units for storing, for example, programs, the inlet water temperature detected by temperature sensors 46-1, 46-2 installed in each gas water heater 24-1, 24-2, the heated temperature detected by temperature sensors 48-1, 48-2, or the outlet water temperature detected by temperature sensors 50-1, 50-2, as well as the inlet water flow rate to the gas water heaters 24-1, 24-2 detected by flow sensors 52-1, 52-2, and also function as a work area for processors 38-1, 38-2 to execute calculations. The communication units 42-1 and 42-2 are examples of functional units that transmit and receive information and control instructions between the remote control 8 and the HP control unit 14, and may be capable of communication processing via wired or wireless means or other means such as short-range infrared communication. Input / output units 44-1, 44-2 are an example of an interface that enables the transmission of control instructions or the reception of detection information between each functional unit of multi-water heater 6. Input / output units 44-1, 44-2 are connected to, for example, temperature sensors 46-1, 46-2, 48-1, 48-2, 50-1, 50-2, and output combustion control instructions from processors 38-1, 38-2 to heat source units 51-1, 51-2.

[0038] <Hot water mode selection setting> 3 and 4 show the hot water supply modes of the hot water supply system 2. The hot water supply mode is selected from among the HP hot water supply unit sole hot water supply mode (A in FIG. 3), the first hybrid hot water supply mode (B in FIG. 3), the second hybrid hot water supply mode (C in FIG. 3), and the multi hot water supply unit sole hot water supply mode (FIG. 4) depending on the heat storage and / or hot water supply amount of the tank unit 12.

[0039] In the HP water heater only hot water supply mode, as shown in A of Fig. 3, only the HP water heater 4 is operated to supply hot water in response to hot water demand. At this time, the multi water heater 6 is in a paused state, water supply W is supplied to the tank unit 12 of the HP water heater 4, and hot water HW pushed out from the tank unit 12 according to the supply amount of this water W is supplied from the HP water heater 4 at the set temperature or at a temperature in a predetermined temperature range including the set temperature. In addition, while supplying hot water, the HP water heater 4 causes the HP unit 10 to perform a heat storage process for the tank unit 12.

[0040] In the first hybrid hot water supply mode, as shown in B of Fig. 3, for example, HP water heater 4 and multi water heater 6 are operated to supply hot water in response to hot water demand. At this time, water supply W is supplied to multi water heater 6 and also to tank unit 12, the hot water output from HP water heater 4 and the hot water output from multi water heater 6 merge in hot water supply circuit 20, and hot water HW at the set temperature or a mixed temperature adjusted to a certain range including the set temperature is discharged. In this example, only gas water heater 24-1 is in operation, but if the hot water demand exceeds the hot water output capacity of gas water heater 24-1, both gas water heaters 24-1 and 24-2 are operated. Moreover, while discharging hot water, HP water heater 4 causes HP unit 10 to perform a heat storage process in tank unit 12. This first hybrid hot water supply mode is a hot water supply mode with heat storage high temperature control that is selected when the heat storage temperature in HP water heater 4 is high and the heat storage amount is sufficient for the hot water supply request, but the total hot water supply amount required is large. In this case, hot water supply system 2 controls the hot water supply load to be borne by utilizing the heat storage in tank unit 12 for the hot water supply demand, for example, or at least half or more of the hot water supply load, and the remaining load is borne by multi-water heater 6. For example, HP control unit 14 adjusts either the hot water supply amount or the hot water supply temperature of HP water heater 4 or both to a predetermined ratio to the hot water supply request temperature or the total hot water supply amount, and performs hot water supply control on the multi-water heater 6 side in response to the hot water supply amount or hot water supply temperature on the HP water heater 4 side. In this way, the first hybrid hot water supply mode aims to improve the energy efficiency of the hot water supply system 2 by preferentially using the stored heat.

[0041] In the second hybrid hot water supply mode, as shown in C of Fig. 3, for example, HP water heater 4 and multi water heater 6 are operated to supply hot water in response to hot water demand. At this time, water supply W is supplied to multi water heater 6 and also to tank unit 12, the hot water output from HP water heater 4 and the hot water output from multi water heater 6 merge in hot water supply circuit 20, and hot water HW at a mixed temperature is discharged. In this example, only gas water heater 24-1 is in operation, but if the hot water demand exceeds the hot water output capacity of gas water heater 24-1, both gas water heaters 24-1 and 24-2 are operated. Moreover, while discharging hot water, HP water heater 4 causes HP unit 10 to perform a heat storage process in tank unit 12. The second hybrid hot water discharge mode is a hot water discharge mode with heat storage low temperature control that is selected when the heat storage temperature in HP water heater 4 is low for the hot water supply request. When the second hybrid hot water discharge mode is set, hot water supply system 2 adjusts the amount and temperature of hot water discharged from HP water heater 4 so as to use as much of the heat stored in energy-efficient tank unit 12 as possible in response to the hot water supply demand, and controls so that the shortfall is made up by discharging hot water from multi water heater 6. In this hot water supply control of HP water heater 4, for example, control is performed to increase the hot water discharge temperature while suppressing the amount of hot water discharged from HP water heater 4, based on the amount of heat calculated from the temperature and flow rate of the hot water supply request and the amount of heat that can be supplied by tank unit 12.

[0042] In the multi-water heater sole hot water supply mode, as shown in Fig. 4, only the multi-water heater 6 is operated to supply hot water in response to hot water demand. At this time, water supply W is supplied only to the multi-water heater 6, the heat of gas combustion by the multi-water heater 6 is heat exchanged with the water supply W, and hot water HW is supplied from the multi-water heater 6 at a set temperature or a predetermined temperature range including the set temperature. In this example, both gas water heaters 24-1, 24-2 are in operation, but if the hot water demand can be met by either gas water heater 24-1, 24-2, only one of the gas water heaters 24-1 or 24-2 is operated. At this time, HP water heater 4, which is disconnected from the hot water supply, operates HP unit 10 and stores heat in tank unit 12 under normal conditions.

[0043] <Hot water supply control> Fig. 5 shows a processing example of hot water supply control. The processing contents and processing procedures shown in Fig. 5 are merely examples, and the technology of the present disclosure is not limited to such a configuration. This hot water supply control is an example of the hot water supply method or program disclosed herein, and includes an upper layer temperature detection process (S101), a heat storage determination process (S102, S103), a hot water output detection process (S104), a hot water output determination process (S105), an HP water heater only hot water output mode (S106), a first hybrid hot water output mode (S107), a second hybrid hot water output mode (S108), and a multi-water heater only hot water output mode (S109).

[0044] Upper layer temperature detection step (S101): The temperature sensor 22 detects the upper layer temperature of the tank unit 12, and transmits this upper layer temperature information to the HP control unit 14. The HP control unit 14 uses the acquired temperature information to calculate the heat storage temperature of the tank unit 12, and monitors its transition.

[0045] Heat storage determination step (S102): HP control unit 14 determines the heat storage temperature of tank unit 12. This heat storage determination is a determination of whether or not the heat storage temperature of tank unit 12 is higher than a threshold value. In this case, it is determined whether or not the temperature information acquired from temperature sensor 22 installed in tank unit 12 is within a temperature range suitable for hot water supply. Therefore, if there is no heat storage in tank unit 12 (NO in S102), the mode transitions to multi-water heater single hot water supply mode (S109), and if there is heat storage (YES in S102), the heat storage determination step (S103) for the hot water supply request is executed.

[0046] Heat storage determination step (S103): The HP control unit 14 determines whether the temperature information acquired from the temperature sensor 22 is higher than the remote control set temperature, which is the target temperature of the hot water supply request, to determine whether the hot water in the tank unit 12 is at a temperature that can meet the hot water supply request. If this determination shows that the upper layer temperature is lower than the remote control set temperature (NO in S103), it is determined that there is no stored heat in the tank unit 12 that can supply hot water alone, and the process transitions to a second hybrid hot water supply mode, which is a heat storage low temperature control (S108). If the upper layer temperature is higher than the remote control set temperature (YES in S103), the process transitions to detection of the hot water supply amount on the HP water heater 4 side (S104).

[0047] Hot water output detection step (S104): In this hot water output detection step, the flow rate of the hot water HW output from the tank unit 12 is detected by the flow rate sensor 25, and the flow rate information detected by the flow rate sensor 25 is notified to the HP control unit .

[0048] Hot water output determination step (S105): HP control unit 14 monitors the transition of the hot water output of HP water heater 4, and determines whether the hot water output on the HP water heater 4 side is equal to or less than a predetermined value, such as a flow rate threshold. If the hot water output on the HP water heater 4 side is equal to or less than the flow rate threshold (YES in S105), the mode transitions to HP water heater only hot water output mode (S106), and if the hot water output exceeds the flow rate threshold (NO in S105), the mode transitions to a first hybrid hot water output mode (S107) as heat storage high temperature control.

[0049] HP water heater only hot water supply mode (S106): This HP water heater only hot water supply mode is an example of the selection process of the only hot water supply mode of the present disclosure. That is, in this mode, since the tank unit 12 has the heat storage required for hot water supply, hot water is supplied only using the HP water heater 4. At this time, the multi-water heater 6 is in a pause state.

[0050] First hybrid hot water discharge mode (S107): This first hybrid hot water discharge mode combines the hot water discharge from the HP water heater 4 and the hot water discharge from the multi water heater 6. In other words, although there is heat storage in the tank unit 12, the hot water discharge rate exceeds the flow rate threshold, so it is determined that the hot water demand cannot be met by the hot water discharge from the HP water heater 4 alone, or that hot water supply alone cannot be continued for a long period of time, and the multi water heater 6 is operated, and the hot water demand that cannot be met is shared between the hot water discharge from the HP water heater 4 and the hot water discharge from the multi water heater 6. In this first hybrid hot water discharge mode (S107), high-temperature heat storage control is performed to efficiently utilize the heat stored in the tank unit 12 and to reduce the operating rate of the multi water heater 6.

[0051] Second hybrid hot water supply mode (S108): This second hybrid hot water supply mode uses both the hot water supply from the HP water heater 4 and the hot water supply from the multi water heater 6 to supply hot water. In other words, although there is heat storage in the tank unit 12, the temperature of the stored heat in the tank unit 12 is not sufficient to meet the hot water demand, so the hot water demand cannot be met by the hot water supply from the HP water heater 4 alone, and the multi water heater 6 is operated. The HP water heater 4 supplies hot water in a manner that uses as much of the stored heat in the tank unit 12 as possible, and the remaining portion is shared by the hot water supply from the multi water heater 6 to meet the hot water demand. In this second hybrid hot water supply mode (S108), heat storage low temperature control is performed to efficiently utilize the heat stored in the tank unit 12 and to reduce the operating rate of the multi water heater 6.

[0052] Multi-water heater single hot water supply mode (S109): This multi-water heater single hot water supply mode is an example of the single hot water supply mode selection process of the present disclosure. That is, in this mode, tank unit 12 does not have the heat storage required for hot water supply, so hot water is supplied only using multi-water heater 6. At this time, HP water heater 4 stops supplying hot water, and tank unit 12 starts storing heat.

[0053] <About hot water supply control table 60> FIG. 6 shows an example of the hot water supply control table 60. This hot water supply control table 60 is formed, for example, in memory unit 32, and is an example of a processing area that calculates the hot water discharge capacity of each of HP water heater 4 and multi water heater 6, and the mixed hot water discharge capacity when these are combined. Hot water supply control table 60 has, for example, an HP water heater information section 61, a multi water heater information section 62, and a post-mixed hot water discharge capacity section 63 formed vertically, and a flow rate information section 64 and a discharge hot water temperature information section 65 formed horizontally. In the hot water supply control, for example, the heat quantity is calculated using the flow rate information and hot water outlet temperature information input into hot water supply control table 60, and the hot water outlet capacity of HP water heater 4 and multi water heater 6 is adjusted based on this heat quantity, and a hot water outlet instruction is generated. Specifically, HP control unit 14 calculates a total hot water outlet amount A+B by combining the hot water outlet amount A on the HP water heater 4 side and the hot water outlet amount B on the multi water heater 6 side, and the hot water outlet temperature X from HP water heater 4 and the hot water outlet temperature Y from multi water heater 6 are input. In the hot water supply control, the outlet hot water temperature after mixing is calculated based on the hot water outlet amount and hot water temperature input into hot water supply control table 60. This calculation of the outlet hot water temperature is performed, for example, using the following formula. (Outlet temperature) = [(A × X) + (B × Y)] / (A + B) (1) In addition, in hot water supply control, for example, this (hot water outlet temperature) may be set as the set temperature for the hot water supply request, for example the set temperature input into remote control 8, and by back-calculating equation (1), the optimal value for either the hot water outlet amount or the hot water outlet temperature from HP water heater 4 or multi-water heater 6, or both, may be calculated, and the hot water supply process may be executed.

[0054] <About hybrid hot water mode> Figures 7 and 8 show examples of the state of the second hybrid hot water discharge mode. The state changes and processing execution timings shown in Figures 7 and 8 are merely examples, and the present invention is not limited to such configurations. In Figures 7 and 8, the horizontal axis shows the passage of time, and the vertical axis shows the flow rate and the hot water discharge temperature, for example.

[0055] For example, when the heat storage temperature in tank unit 12 is low for the hot water supply request, or when the heat storage temperature drops below the set temperature for the hot water supply request during hot water supply, hot water supply system 2 uses multi-water heater 6 in combination to supply hot water to make up for the shortage of heat. The hot water supply process shown in Figure 7 shows a case where only one of gas water heater 24-1 or gas water heater 24-2 on the multi-water heater 6 side is operated as a processing example when the total hot water output amount for the hot water supply request is small, for example, about 8 [L / min], or when the hot water output amount from tank unit 12 is increased.

[0056] 7, hot water supply system 2 is in a standby state until a hot water supply request occurs at or before time t1, and when the hot water supply request is issued, hot water supply processing is started by HP water heater 4 at time t1. Then, for example, if the heat storage temperature in tank unit (TU) 12 falls below the set temperature of the hot water supply request while hot water supply is continuing, hot water supply system 2 transitions to the second hybrid hot water supply mode and outputs a hot water supply instruction to multi water heater 6.

[0057] At this time, the HP control unit 14 generates, for example, a hot water supply control table 60, sets a value that suppresses the hot water output from the HP water heater 4, and sets the total hot water output based on the set temperature of the hot water supply request and the water supply volume detected by the flow sensor 23. From this information, it calculates optimal values ​​for the output temperature, flow rate, and hot water output temperature from the HP water heater 4 on the multi-water heater 6 side in order to make the most of the heat stored in the tank unit 12, and sets the number of gas water heaters 24-1, 24-2 in operation and the equipment to be operated. In hot water supply system 2, for example, when the hot water supply process is started in the second hybrid hot water supply mode, the hot water supply amount of gas water heater 24-1 or gas water heater 24-2 becomes the calculated set value at time t3, so that the actual hot water supply temperature, which is the mixed temperature with the hot water supplied from HP water heater 4, can be adjusted to be the same as the set temperature of the hot water supply request or within a specified range.

[0058] In addition, in the hot water supply process, for example, when a hot water supply request occurs at time t1, hot water supply may be started by combining the HP water heater 4 and the gas water heater 24-1 regardless of whether the heat storage temperature in the tank unit 12 is at a temperature that can meet the hot water supply request.

[0059] The hot water supply process shown in Figure 8 shows a case where the total hot water output required is large, for example 18 L / min, or as an example of processing to suppress the amount of hot water output from tank unit 12 and make the hot water output temperature as high as possible, a case where both gas water heater 24-1 and gas water heater 24-2 on the multi-water heater 6 side are operated.

[0060] In hot water supply system 2, when a hot water supply request is issued, hot water supply processing by HP water heater 4 in combination with gas water heater 24-1 is started at time t1, as shown in Fig. 8 for example. In this case, the hot water supply control, for example, equalizes the hot water output amount and output temperature between tank unit 12 and gas water heater 24-1, and realizes the total hot water supply amount and output temperature corresponding to the hot water supply request. Then, for example, when the heat storage temperature in tank unit (TU) 12 drops below the set temperature of the hot water supply request while hot water supply is continuing, hot water supply system 2 transitions to the second hybrid hot water output mode and outputs an operation start instruction to gas water heater 24-2 of multi-water heater 6 that is paused.

[0061] At this time, the HP control unit 14 controls, for example, the hot water control table 60 to a predetermined value set in order to suppress the amount of hot water output from the HP water heater 4, and recalculates the output temperature and flow rate, etc. on the multi-water heater 6 side based on the set temperature of the hot water supply request and the total amount of hot water output, increases the output temperature to the gas water heaters 24-1, 24-2, adjusts the amount of hot water output, and further adjusts the amount of hot water output, output temperature, etc. from the HP water heater 4. In the hot water supply system 2, for example, when the hot water supply process is started in the second hybrid hot water supply mode, the hot water supply amount of the added gas water heater 24-2 at time t3 becomes the recalculated set value, so that the actual hot water supply temperature, which is the mixed temperature with the hot water supplied from the HP water heater 4, can be adjusted to be the same as the set temperature of the hot water supply request or within a specified range. In the hot water supply system 2, for example, the heat storage state in the tank unit 12 is continuously monitored, and in response to changes in that state, the hot water output amount and output temperature of the HP water heater 4 and the hot water output amount and output temperature of the multi-water heater 6 are recalculated based on the heat quantity of the hot water request and the heat quantity of hot water output from the hot water supply system 2.

[0062] 8 shows a case where the heat storage temperature of tank unit 12 drops, the amount of hot water output from HP water heater 4 is suppressed, and the actual amount of hot water output decreases after time t2 when gas water heater 24-2 starts operating, but is not limited to such processing. In hot water control, for example, around time t2, the amount of hot water output from gas water heaters 24-1, 24-2 may be set to compensate for the decrease in the amount of hot water output from HP water heater 4, thereby maintaining the actual amount of hot water output.

[0063] <Hot water supply control> Fig. 9 shows an example of hot water supply control in the hybrid hot water supply mode. The process contents and process procedures shown in Fig. 9 are examples, and the technology of the present disclosure is not limited to such configuration. In addition, the process contents shown here are an example of the hot water supply method and hot water supply program of the present disclosure.

[0064] This hot water supply control shows an example of processing when, for example, in the hot water supply control of Figure 5, the first hybrid hot water supply mode (S107) or the second hybrid hot water supply mode (S108) is transitioned to, and hot water supply processing is performed according to the heat storage state in the tank unit 12 and the set temperature of the hot water supply request, etc. This hot water supply process includes, for example, as shown in FIG. 9, a flow rate determination process (S201), a heat storage determination process (S202), a heat storage high temperature control process (S203), hot water discharge control (S204), a time passage determination process (S205), a temperature determination process (S206), a heat storage low temperature control process (S207), hot water discharge control (S208), a heat storage low temperature control cancellation process (S209), and a hybrid hot water discharge mode cancellation process (S210).

[0065] Flow rate determination process (S201): The HP control unit 14 is in a standby state until it obtains a flow rate detection signal from the flow rate sensor 23 (NO in S201), and when water supply W is detected by the flow rate sensor 23, for example, by opening the hot water tap (YES in S201), the HP control unit 14 starts the hot water supply process. Heat storage determination step (S202): The HP control unit 14 acquires temperature information indicating the heat storage temperature from the temperature detected by the temperature sensor 22, and determines the heat storage temperature of the tank unit 12. In this heat storage determination step, it determines whether the upper layer temperature is equal to or lower than the remote control set temperature, and if it is higher than the remote control set temperature (NO in S202), it sets the heat storage high temperature control to ON as the first hybrid hot water discharge mode (S203), and transitions to hot water discharge control (S204). Heat storage high temperature control process (S203): The HP control unit 14 sets the hot water outlet temperature and hot water outlet volume from the HP water heater 4 to values ​​close to the hot water supply request, for example in the hot water supply control table 60, and generates a hot water supply instruction for the multi-water heater 6 side to make up for the shortfall in the hot water supply volume relative to the hot water supply request. Hot water discharge control (S204): HP control unit 14 outputs the hot water discharge temperature and hot water discharge amount set in hot water supply control table 60 to HP water heater 4 and multi water heater 6, and causes them to supply hot water by heat storage high temperature control.

[0066] Time lapse determination step (S205): If the temperature of the upper layer in the tank unit 12 is lower than the remote control set temperature (S202), the HP control unit 14 waits until a standby time tm, for example, 3 [sec] has elapsed. This standby time tm is intended to suppress the influence of temperature fluctuations caused by the inflow of water W into the tank unit 12 when hot water supply starts, for example. When the standby time tm has elapsed, the process proceeds to a temperature determination step (S206) of the upper layer temperature in the tank unit 12. Temperature determination step (S206): The HP control unit 14 determines whether the temperature of the upper layer inside the tank unit 12 is higher than, for example, 45°C as a threshold value P. This temperature threshold value P is, for example, the lowest heat storage temperature at which hot water can be dispensed at the set temperature or a temperature range including the set temperature in the second hybrid hot water dispensing mode, and the temperature threshold value is not limited to this temperature.

[0067] Heat storage low temperature control process (S207): When the upper layer temperature in tank unit 12 is higher than threshold value P (YES in S206), HP control unit 14 sets the heat storage low temperature control, which is the second hybrid hot water discharge mode, to ON and transitions to hot water discharge control (S208). Also, when the upper layer temperature is equal to or lower than threshold value P (NO in P206), HP control unit 14 cancels (OFF) the heat storage low temperature control setting (S209). For example, as the heat storage low temperature control process, HP control unit 14 sets the hot water discharge amount from HP water heater 4 to a set amount in hot water supply control table 60 that is suppressed, and generates a hot water supply instruction for multi water heater 6 to make up for the shortfall in hot water discharge temperature and hot water discharge amount in response to the hot water supply request. Hot water discharge control (S208): HP control unit 14 outputs the hot water discharge temperature and hot water discharge amount set in hot water supply control table 60 to HP water heater 4 and multi water heater 6, and causes them to supply hot water by heat storage low temperature control.

[0068] Processing to cancel heat storage low temperature control (S209): When the HP control unit 14 determines that hot water cannot be supplied using the HP water heater 4 based on the heat storage state in the tank unit 12 (S206), it performs processing to stop the hybrid hot water supply control. Hybrid hot water discharge mode release process (S210): Due to the release of the heat storage low temperature control (S209), the HP control unit 14 determines that the tank unit 12 does not have the amount of stored heat required to execute the hybrid hot water discharge mode, and returns to S101 in FIG.

[0069] <Effects of one embodiment> According to this configuration, any one of the following effects can be obtained. (1) The heat storage state is determined from the temperature of the upper layer in the tank unit 12, and a multi-stage hybrid hot water supply mode is set according to the required hot water temperature and flow rate conditions, thereby making it possible to utilize the heat stored in the HP water heater 4 as effectively as possible. (2) By adjusting the outlet temperature and amount of hot water so as to make greater use of the heat stored in the HP water heater 4, the energy efficiency of the hot water supply system 2 can be improved. (3) By monitoring the decrease in the heat storage state within tank unit 12 and immediately operating multi-water heater 6 to compensate for the lack of heat when the amount of stored heat is insufficient, hot water can be supplied at a temperature and flow rate that meets the hot water supply demand. EXAMPLES

[0070] Next, an example of the heat storage low temperature control, which is the second hybrid hot water discharge mode, will be described. Fig. 10 is a flow chart showing an example of hot water supply control in the hybrid hot water supply mode. The process contents and process steps shown in Fig. 10 are only an example.

[0071] HP control unit 14 monitors operation of remote control 8 from, for example, a standby state (S301), and if remote control 8 operates (YES in S301), monitors whether a flow rate has occurred in hot water supply system 2 (S302). In hot water supply system 2, for example, before a flow rate occurs (NO in S302), the hot water outlet temperature on the HP water heater 4 and multi water heater 6 sides is set to the remote control set temperature Tx (for example, 60 [°C]), which is the target temperature of the hot water supply request, and the hot water output rates of HP water heater 4 and multi water heater 6 are both set to 0 [L / min]. Then, in hot water supply system 2, when the flow rate sensor detects a flow rate (YES in S302), the hot water output rate of HP water heater 4 changes from 0 [L / min] to hot water output rate Q1 [L / min], and the hot water output rate of multi water heater 6 changes from 0 [L / min] to hot water output rate Q2 [L / min]. These hot water output rates Q1 and Q2 may be values ​​obtained by equally dividing the total hot water output rate of the hot water supply request, for example.

[0072] When a flow rate is generated, the HP control unit 14 determines whether the temperature of the upper layer of the tank unit 12 detected by the temperature sensor 22 is lower than the temperature set by the remote control (S303), and if the temperature of the upper layer is less than the temperature set by the remote control (YES in S303), it moves on to determining whether the heat stored in the tank unit 12 can be used for hot water supply, and sets the hot water output from the HP water heater 4 to 0 [L / min] and the hot water output from the multi water heater 6 to Q3 [L / min]. This hot water output Q3 is equal to the total hot water output requested.

[0073] When HP control unit 14 waits for a predetermined time tn, for example 3 seconds, of the hot water discharge state from multi water heater 6 alone, it determines whether the temperature of the upper layer of tank unit 12 is higher than a threshold temperature Ts, for example 45°C (S305). If the temperature of the upper layer of tank unit 12 is >Ts (YES in S305), HP control unit 14 sets the second hybrid hot water discharge mode, which also uses multi water heater 6 as heat storage low temperature control, to ON (S306), calculates the hot water discharge temperature of HP water heater 4 (S307), and discharges hot water (S308). In this calculation process for the hot water outlet temperature, for example, the regulated hot water outlet rate QL on the HP water heater 4 side is set to a suppressed set value of 3 [L / min], and the hot water outlet temperature Tm is set to a lower value than the remote control set temperature Tx, for example 40 [°C]. Also, on the multi-water heater 6 side, for example, the flow rate Qx [L / min] is set to 12 [L / min] based on the regulated hot water outlet rate QL on the HP water heater 4 side, and the hot water outlet temperature TH is set to 65 [°C], for example, to mix with the hot water outlet from the HP water heater 4 and output hot water at the remote control set temperature Tx.

[0074] In addition, in the heat storage low temperature control, conditions may be set such as calculating the optimal values ​​of the outlet temperatures Tm, TH and outlet amounts QL, Qx of the HP water heater 4 and the multi water heater 6 so that the mixed temperature of the HP water heater 4 and the multi water heater 6 is within a range of approximately 2°C of the remote control set temperature Tx, or setting the outlet temperature TH on the multi water heater 6 side to a predetermined temperature, for example 5°C higher than the remote control set temperature.

[0075] Furthermore, if the temperature of the upper layer side of tank unit 12 is not greater than Ts (NO in S305), HP control unit 14 determines that there is no heat storage amount sufficient for hot water discharge processing in the second hybrid hot water discharge mode, and sets the heat storage low temperature control to OFF (S309). In this case, HP control unit 14 may set the single operation mode by multi-hot water heater 6, for example.

[0076] When hot water supply processing is performed in the second hybrid hot water supply mode, a hot water supply control table 60 is generated in HP control unit 14, as shown in Fig. 11, for example, and when the hot water output amounts for HP water heater 4 and multi water heater 6 are set, a calculation process is performed to calculate the optimal hot water output temperature to meet the hot water supply request. In the calculation process of the optimal hot water output temperature in heat storage low temperature control, the optimal hot water output amount Qx of multi water heater 6 is calculated based on the hot water output amount QL and hot water output temperature Tm on the HP water heater 4 side for the remote control set temperature and total hot water output amount, which are the target temperatures for the hot water supply request. The hot water output temperature Tm of HP water heater 4 is affected by the amount of heat stored in tank unit 12. The flow rate Qx of multi-water heater 6 is set to a value obtained by subtracting the flow rate QL of HP water heater 4 from the total hot water output amount Q3 after mixing, for example. Also, the outlet temperature TH of the multi-water heater 6 may be set to a value obtained by adding, for example, 5°C to the remote control set temperature Tx as a predetermined temperature. In this case, the set temperature on the multi-water heater 6 side is fixed at TH, and the outlet temperature of the HP water heater 4 is changed to Tm1, Tm2, ​​and Tm3 to obtain the optimal value of the outlet temperature of the HP water heater 4. The outlet temperatures Tx1, Tx2, and Tx3 after mixing corresponding to the outlet temperatures Tm1, Tm2, ​​and Tm3 of the HP water heater 4 are calculated, and the outlet temperature of the HP water heater 4 when the outlet temperature after mixing can be kept within a range of about 2°C from the remote control set temperature is calculated. The outlet temperature of the HP water heater 4 is the highest possible value, that is, the temperature that utilizes the heat stored in the tank unit 12 as much as possible, which is the optimal value here. In the calculation process of the hot water outlet temperature of this HP water heater 4, for example, if the mixed hot water outlet temperatures Tx1, Tx2, Tx3 corresponding to the set hot water outlet temperatures Tm1, Tm2, ​​Tm3 do not fall within a range of 2°C from the remote control set temperature, the regulated hot water outlet amount QL of the HP water heater 4 can be changed and the calculation process can be performed again.

[0077] In the process of calculating the optimum value of the hot water outlet temperature of multi water heater 6, for example, when the ratio of the hot water outlet volume of HP water heater 4 to the total hot water outlet volume is large, or when the hot water outlet temperature after mixing differs by more than 2°C from the remote control set temperature which is the target temperature of the hot water supply request, the optimum value of the hot water outlet temperature of multi water heater 6 may be calculated from the heat storage temperature and heat storage volume on the HP water heater 4 side and the heat volume of the hot water supply request. This calculation process based on the heat volume is found, for example, by integrating the flow rate and the hot water outlet temperature.

[0078] [Modifications] The features and modifications of the above-described embodiment will be listed below.

[0079] (1) In the above embodiment and example, the hot water supply system 2 includes an HP water heater 4 having one tank unit 12 and a multi-water heater 6 having two gas water heaters 24-1, 24-2, but is not limited to this. In the hot water supply system 2 of the present disclosure, for example, one HP water heater 4 may include two or more tank units 12, or multiple HP water heaters 4 having one or more tank units 12 may be linked together. In addition, the hot water supply system 2 may include one gas water heater 24, a multi-water heater 6 having three or more gas water heaters 24-1, 24-2, 24-3, etc., or multiple multi-water heaters 6 having two gas water heaters 24-1, 24-2 may be linked together.

[0080] (2) In the above embodiment and example, a processing example was shown in which the amount of hot water output from HP water heater 4 is fixed to a minimum set value as heat storage low temperature control, and the heat amount that is insufficient for the hot water supply request is made up for by multi water heater 6, but this is not limited to the above. In the hot water supply processing of heat storage low temperature control, for example, the amount of hot water output from HP water heater 4 may be adjusted to increase or decrease stepwise at a predetermined timing based on the heat storage temperature in tank unit 12, and the shortfall may be made up for by multi water heater 6. In this case, the amount and temperature of hot water output from multi water heater 6 may be controlled to be higher than those from HP water heater 4, and to output more hot water.

[0081] (3) In the above embodiment and example, in the second hybrid hot water discharge mode, the amount of hot water discharged from HP water heater 4 is suppressed based on the heat storage state of tank unit 12, and hot water supply control is performed to increase the hot water discharge temperature, thereby making greater use of the heat stored in tank unit 12; however, the present invention is not limited to such processing. For example, in the heat storage low temperature control, hot water supply system 2 may suppress the amount of hot water discharged from HP water heater 4 and suppress the hot water discharge temperature to be lower than a predetermined threshold value. The threshold value for this hot water discharge temperature may be set, for example, based on a temperature that is a predetermined temperature lower than the heat storage temperature in tank unit 12. As a result, in the hot water supply system 2, the heat stored in the tank unit 12 can be utilized for a long period of time in the heat storage low temperature control.

[0082] As described above, preferred embodiments and examples of the technology of the present disclosure have been described. The technology of the present disclosure is not limited to the above description. Based on the gist of the invention described in the claims or disclosed in the form for carrying out the invention, those skilled in the art can make various modifications and changes. It goes without saying that such modifications and changes are included in the technical scope of the present disclosure. [Industrial Applicability]

[0083] The hot water supply method, system, and program disclosed herein are useful in a hot water supply system that combines an HP water heater that stores heat from a heat pump in a tank unit and a multi-water heater equipped with a gas water heater, because they can optimize the hot water outlet conditions on the HP water heater side according to the heat storage state in the tank unit and supply hot water together with the multi-water heater, thereby increasing the efficiency of utilization of the heat stored in the hot water tank. [Explanation of symbols]

[0084] 2. Hot water system 4 HP Water Heater 6. Multi-water heater 8. Remote Control 10 HP Unit 12 Hot water tank unit 14 HP control unit 16 Circulation path 18 Water supply circuit 20 Hot water circuit 22, 46-1, 46-2, 48-1, 48-2, 50-1, 50-2 Temperature Sensor 23, 25, 52-1, 52-2 Flow sensor 24-1, 24-2, 24-3 Gas water heater 26-1, 26-2 Hot water supply control unit 30, 38-1, 38-2 processors 32, 40-1, 40-2 Memory section 34, 42-1, 42-2 Communications Department 36, 44-1, 44-2 Input / output section 51-1, 51-2 Heat source machine 60 Hot water supply control table 61 HP Water Heater Information Department 62 Multi-water heater information department 63 Mixed molten metal outlet capacity 64 Flow rate information section 65 Hot water temperature information section

Claims

1. A hot water supply method using a first hot water supply means for storing hot water heated by a heat pump in a hot water storage tank and supplying hot water from the hot water storage tank in combination with a second hot water supply means for heating water by a heat source other than the heat pump and supplying the water, a control unit of the first hot water supply means determining a hot water supply capacity due to a heat storage state of the hot water storage tank based on a temperature of hot water at least at a predetermined height position in the hot water storage tank detected by a temperature detection means, and selecting a single hot water supply mode in which hot water is supplied from either the first hot water supply means or the second hot water supply means, or a hybrid hot water supply mode in which the first hot water supply means and the second hot water supply means are used in combination, based on the temperature, or on the temperature and a total hot water supply amount requested; A hot water supply method comprising:

2. The control unit selects the single hot water supply mode in which hot water is supplied only by the second hot water supply means if the temperature is equal to or lower than a threshold value, or selects the single hot water supply mode in which hot water is supplied only by the first hot water supply means if the temperature is higher than the threshold value and the total hot water supply amount is equal to or lower than a predetermined value; The hot water supply method according to claim 1 , comprising:

3. a step of selecting either a first hybrid hot water outlet mode in which, when the temperature is higher than the threshold value but the total hot water outlet volume is greater than a flow rate threshold value, either one or both of the hot water outlet volume and the hot water outlet temperature from the first hot water supply means are adjusted within a predetermined range and hot water is supplied in combination with the second hot water supply means, or a second hybrid hot water outlet mode in which, when the temperature is higher than the threshold value but the temperature in the hot water storage tank is equal to or lower than the required hot water supply temperature, the hot water outlet volume from the first hot water supply means is suppressed and the hot water outlet temperature is adjusted, and hot water is supplied in combination with the second hot water supply means; The hot water supply method according to claim 1 or 2, comprising:

4. a step in which the control unit controls a mixed temperature obtained by the hot water outlet temperature from the first hot water supply means calculated from the hot water outlet amount of the first hot water supply means and the temperature of the hot water at a predetermined height position in the hot water storage tank, and the hot water outlet temperature from the second hot water supply means calculated from the hot water outlet amount of the second hot water supply means, to be the same as the hot water outlet set temperature or to a certain range including the same value, during execution of the hybrid hot water outlet mode; The hot water supply method according to claim 1 , comprising:

5. If the control unit defines the amount of hot water discharged from the first hot water supply means as Q1, the hot water discharge temperature from the first hot water supply means as T1, the amount of hot water discharged from the second hot water supply means as Q2, the hot water discharge temperature from the second hot water supply means as T2, and the total amount of hot water discharged as Q, then the mixed temperature T obtained from this total amount of hot water discharged Q is: T=(Q1×T1+Q2×T2)÷Q The process of obtaining The hot water supply method according to claim 4, comprising:

6. A hot water supply system using a first hot water supply means that stores hot water heated by a heat pump in a hot water storage tank and supplies hot water from the hot water storage tank, and a single or multiple second hot water supply means that heats water using a heat source other than the heat pump and supplies hot water, a temperature detection means for detecting a temperature of the hot water at a predetermined height position in the hot water storage tank; A flow rate monitoring means for monitoring a total hot water supply amount requested; a control means for determining a hot water supply capacity according to a heat storage state of the hot water storage tank based on the temperature detected in the hot water storage tank, and for selecting a single hot water supply mode in which hot water is supplied from either the first hot water supply means or the second hot water supply means based on the temperature or the temperature and the total hot water supply amount, or a hybrid hot water supply mode in which the first hot water supply means and the second hot water supply means are used in combination; A hot water supply system comprising:

7. The control means selects the single hot water supply mode in which hot water is dispensed only by the second hot water supply means if the temperature is equal to or lower than a threshold value, or selects the single hot water supply mode in which hot water is dispensed only by the first hot water supply means if the temperature is higher than the threshold value and the total amount of dispensed hot water is equal to or lower than a predetermined value. The hot water supply system according to claim 6 .

8. When the temperature is higher than the threshold value but the total hot water output is greater than the flow rate threshold value, the control means selects either a first hybrid hot water output mode in which either one or both of the hot water output and the hot water output temperature from the first hot water supply means are adjusted within a predetermined range and hot water is output in combination with the second hot water supply means, or when the temperature is higher than the threshold value but the temperature in the hot water storage tank is equal to or lower than the hot water supply request temperature, the control means selects either a first hybrid hot water output mode in which the hot water output and the hot water output temperature from the first hot water supply means are suppressed and the hot water output temperature is adjusted and hot water is output in combination with the second hot water supply means.

8. The hot water supply system according to claim 6 or 7.

9. During execution of the hybrid hot water discharge mode, the control means controls a mixed temperature obtained by the hot water discharge temperature from the first hot water supply means calculated from the hot water discharge amount of the first hot water supply means and the hot water temperature at a predetermined height position in the hot water storage tank, and the hot water discharge temperature from the second hot water supply means calculated from the hot water discharge amount of the second hot water supply means, to be the same as the hot water discharge setting temperature or to a certain range including the same value. The hot water supply system according to claim 6 .

10. A computer program for a hot water supply system using a first hot water supply means that stores hot water heated by a heat pump in a hot water storage tank and supplies hot water from the hot water storage tank, and a single or multiple second hot water supply means that heats water using a heat source other than the heat pump and supplies hot water, a function of determining the hot water supply capacity according to the heat storage state of the hot water storage tank based on the temperature of the hot water at least at a predetermined height position in the hot water storage tank detected by a temperature detection means, and selecting a single hot water supply mode in which hot water is supplied from either the first hot water supply means or the second hot water supply means based on said temperature or on said temperature and the total hot water supply amount requested, or a hybrid hot water supply mode in which the first hot water supply means and the second hot water supply means are used in combination; A program for causing the computer to execute the above.

11. A function of selecting the single hot water supply mode in which hot water is dispensed only by the second hot water supply means if the temperature is equal to or lower than a threshold value, or selecting the single hot water supply mode in which hot water is dispensed only by the first hot water supply means if the temperature is higher than the threshold value and the total amount of hot water dispensed is equal to or lower than a predetermined value; The program according to claim 10, which causes the computer to execute the steps of:

12. a function of selecting either a first hybrid hot water outlet mode in which, when the temperature is higher than the threshold value but the total hot water outlet volume is greater than the flow rate threshold value, either one or both of the hot water outlet volume and the hot water outlet temperature from the first hot water supply means are adjusted within a predetermined range and hot water is supplied in combination with the second hot water supply means, or a second hybrid hot water outlet mode in which, when the temperature is higher than the threshold value but the temperature in the hot water storage tank is equal to or lower than the required hot water supply temperature, the hot water outlet volume from the first hot water supply means is suppressed and the hot water outlet temperature is adjusted, and hot water is supplied in combination with the second hot water supply means; The program according to claim 10 or 11, which causes the computer to execute the steps of:

13. a function of controlling, during execution of the hybrid hot water discharge mode, a mixed temperature obtained by the hot water discharge temperature from the first hot water supply means calculated from the hot water discharge amount of the first hot water supply means and the temperature of the hot water at a predetermined height position in the hot water storage tank, and the hot water discharge temperature from the second hot water supply means calculated from the hot water discharge amount of the second hot water supply means, to be the same as the hot water discharge set temperature or to a certain range including the same value; The program according to claim 10 or 11, which causes the computer to execute the steps of:

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