Hot water supply method, system, and program

Abstract

To continue a hot water supply process in accordance with a hot water supply request without significantly affecting the heat storage state of a hot water storage tank with respect to a change in a total amount of hot water tapping.SOLUTION: A hot water supply method for a hot water supply system (2, 70) that can use both a first hot water supply means (4, 72) which supplies hot water heated by a first heat source (10, 74) and stored in a hot water storage tank (12) and a second hot water supply means (multi water heater 6) which supplies hot water heated by second heat sources (gas water heaters 24-1, 24-2). When a total amount of hot water tapping changes during hot water supply under a hot water tapping condition in which a control unit (14, 82) of the first hot water supply means decreases a hot water tapping temperature and an amount of hot water tapping of the first hot water supply means in response to reduction in a heat storage temperature in the hot water storage tank than a preset temperature of the hot water supply request and increases a hot water tapping temperature of the second hot water supply means higher than the hot water supply request, a hot water supply instruction is generated for modifying the amount of hot water tapping from the first hot water supply means, a hot water tapping temperature, and an amount of hot water tapping from the second hot water supply means with the total amount of hot water tapping after the change and the preset temperature of the hot water supply request with respect to the hot water tapping condition.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 stores hot water preheated by a heat source in a hot water storage tank, and a hot water supply means that generates hot water by heating cold water when supplying hot water. [Background technology]

[0002] Hybrid hot water systems that combine hot water supply means that include a heat pump or hot water storage tank as a heat source with hot water supply means that include a heat source other than a heat pump are already known, and multi-hot water supply systems that use multiple gas water heaters as 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 on the hot water supply route 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 to a lower temperature 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 and the target temperature before the temperature change is maintained even after the temperature change (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-349202 [Patent Document 2] Japanese Patent Application 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 that stores hot water heated by a heat source with a hot water supply means (or a multi-hot water supply system) that heats water to produce hot water when supplying hot water, for example, an HP water heater including a heat pump (HP) and a hot water storage tank, and a GB water heater that uses a heat source other than a heat pump, for example a gas boiler (GB), can be provided, and hot water can be supplied by selecting either the HP water heater or the GB water heater to operate alone, or by operating the HP water heater and the GB water heater together.

[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. Even if it is not possible to add more heat storage to the hot water storage tank, or even if it is possible to add more, if the amount of stored heat consumed by discharging the hot water is greater than the amount of stored heat, the temperature of the hot water at the outlet will drop. Furthermore, even when operating an HP water heater and a GB water heater together, if the amount of stored heat consumed is set to exceed the amount of heat stored in the tank unit, the temperature of the hot water at the outlet will similarly drop.

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

[0009] The inventors of the technology disclosed herein have discovered that when supplying hot water in a hot water outlet operation mode in which a GB water heater is used in combination with an HP water heater, which reduces the hot water outlet temperature and volume and outputs hot water at a temperature higher than the set temperature of the hot water supply request, if the total hot water output volume of the hot water supply request fluctuates, the responsiveness to changes in the total hot water output volume can be improved by readjusting the hot water output temperature and volume from the HP water heater.

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

[0011] Another object of the present disclosure is to continue hot water supply processing in accordance with hot water supply requests when the total amount of hot water output changes, without significantly affecting the heat storage state in the hot water storage tank. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, one aspect of the hot water supply method disclosed herein is a hot water supply method for a hot water supply system that can use both a first hot water supply means that supplies hot water using hot water heated by a first heat source and stored in a hot water storage tank, and a second hot water supply means that supplies hot water using hot water heated by a second heat source, and includes a step of monitoring the total hot water output based on the detection result of a flow detection means while supplying hot water in a hybrid hot water output mode in which a control unit of the first hot water supply means operates under hot water output conditions that reduce the hot water output temperature and hot water output rate of the first hot water supply means in response to the heat storage temperature in the hot water storage tank becoming lower than the set temperature of the hot water supply request, and set the hot water output temperature of the second hot water supply means to be higher than the set temperature of the hot water supply request, and a step of generating a hot water output instruction, when the control unit confirms a change in the total hot water output rate, to modify at least one of the hot water output rate or hot water output temperature from the first hot water supply means, or a combination of these, for the hot water output conditions of the hybrid hot water output mode, based on the changed total hot water output rate and the set temperature of the hot water supply request.

[0013] In the above hot water supply method, the control unit, upon determining that the total hot water output has changed, maintains the hot water output of the first hot water supply means and the hot water output temperature of the second hot water supply means among the hot water output conditions, calculates the hot water output of the second hot water supply means from the changed total hot water output, and modifies the hot water output conditions including the hot water output temperature of the first hot water supply means within a specified temperature limit range, and determines whether hot water can be output at the same value as the set temperature of the hot water supply request or within a certain range including that same value based on the heat quantity calculated from the hot water output and hot water output temperature of the first hot water supply means and the second hot water supply means; and if the control unit determines that hot water cannot be output at the set temperature of the hot water supply request under the modified hot water output conditions, adjusts the hot water output of the first hot water supply means, and adjusts the hot water output conditions based on the adjusted hot water output and the heat quantity of the hot water supplied from the first hot water supply means and the second hot water supply means. The above-mentioned hot water supply method includes a step in which the control unit sets the hot water discharge conditions in which the hot water discharge amount of the first hot water supply means is changed in stages by a predetermined value, and compares the difference between the discharge temperature of the hot water after mixing, calculated based on the heat quantity of the hot water discharged from the first hot water supply means and the set temperature of the hot water supply request, and a step in which the control unit adjusts the hot water discharge amount of the first hot water supply means among the hot water discharge conditions, based on the comparison, so that the positive and negative values ​​of the difference between the discharge temperature of the hot water after mixing and the set temperature are reversed.

[0014] In order to achieve the above-mentioned object, one aspect of the hot water supply system of the present disclosure is a hot water supply system that can use both a first hot water supply means that supplies hot water using hot water heated by a first heat source and stored in a hot water storage tank, and a second hot water supply means that supplies hot water using hot water heated by a second heat source, and is equipped with a flow detection means that detects the total hot water output amount of a hot water supply request, and a control means that, during hot water supply in a hybrid hot water supply mode in which the hot water output temperature and hot water output amount of the first hot water supply means are reduced in response to the heat storage temperature in the hot water storage tank becoming lower than the set temperature of the hot water supply request, and the second hot water supply means is operated under hot water output conditions that make the hot water output temperature higher than the set temperature of the hot water supply request, monitors changes in the total hot water output amount of the hot water supply request based on the detection results of the flow detection means, and when a change in the total hot water output amount is confirmed, generates a hot water output instruction to modify at least the hot water output amount or the hot water output temperature from the first hot water supply means, or a combination of these, for the hot water output conditions of the hybrid hot water supply mode, based on the changed total hot water output amount and the set temperature of the hot water supply request.

[0015] In the above-mentioned hot water supply system, the control means, in response to a change in the total hot water output volume, maintains the hot water output volume of the first hot water supply means and the hot water output temperature of the second hot water supply means among the hot water output conditions, calculates the hot water output volume of the second hot water supply means from the changed total hot water output volume, and modifies the hot water output conditions including the hot water output temperature of the first hot water supply means within a specified temperature limit range, and determines whether hot water can be output at the same value as the set temperature of the hot water supply request or within a certain range including that same value based on the heat quantity calculated from the hot water output volume and hot water output temperature of the first hot water supply means and, if it determines that hot water cannot be output at the set temperature of the hot water supply request under the modified hot water output conditions, adjusts the hot water output volume of the first hot water supply means, and adjusts the hot water output conditions based on this adjusted hot water output volume and the heat quantity of the hot water supplied from the first hot water supply means and the second hot water supply means. In the above-mentioned hot water supply system, the control means sets the hot water discharge conditions in which the hot water discharge amount of the first hot water supply means is changed in stages by predetermined values, compares the difference between the discharge temperature of the hot water after mixing, calculated based on the heat quantity of the hot water discharged from the first hot water supply means and the set temperature of the hot water supply request, and adjusts the hot water discharge amount of the first hot water supply means among the hot water discharge conditions based on this comparison so that the positive and negative values ​​of the difference between the discharge temperature of the hot water after mixing and the set temperature are reversed. In the above-mentioned hot water supply system, the first heat source of the first hot water supply means uses air heat using a heat pump or solar heat using a solar collector, and the second heat source of the second hot water supply means uses heat generated by burning fuel gas.

[0016] In order to achieve the above-mentioned object, one aspect of the program disclosed herein is a computer program for a hot water supply system that can use both a first hot water supply means that supplies hot water using hot water heated by a first heat source and stored in a hot water storage tank, and a second hot water supply means that supplies hot water using hot water heated by a second heat source, and the computer is caused to execute the following functions during hot water supply in a hybrid hot water supply mode in which the first hot water supply means operates under hot water supply conditions that reduce the hot water outlet temperature and hot water outlet volume in response to the heat storage temperature in the hot water storage tank becoming lower than the set temperature of the hot water supply request, and the second hot water supply means operates under hot water supply conditions that make the hot water outlet temperature higher than the set temperature of the hot water supply request: a function to monitor the total hot water output volume based on the detection results of a flow detection means; and a function to generate a hot water output instruction that, when a change in the total hot water output volume is confirmed, modifies at least one of the hot water output volume or hot water output temperature from the first hot water supply means, or a combination of these, for the hot water supply conditions of the hybrid hot water supply mode, based on the changed total hot water output volume and the set temperature of the hot water supply request.

[0017] In the above program, the computer is caused to execute the following functions: when a change in the total hot water output volume occurs, maintain the hot water output volume of the first hot water supply means and the hot water output temperature of the second hot water supply means among the hot water output conditions, calculate the hot water output volume of the second hot water supply means from the changed total hot water output volume, and modify the hot water output conditions including the hot water output temperature of the first hot water supply means within a specified temperature limit range; determine whether hot water can be output at the same value as the set temperature of the hot water supply request or within a certain range including that same value based on the heat quantity calculated from the hot water output volume and hot water output temperature of the first hot water supply means and the second hot water supply means; and if it is determined that hot water cannot be output at the set temperature of the hot water supply request under the modified hot water output conditions, adjust the hot water output volume of the first hot water supply means and modify the hot water output conditions based on this adjusted hot water output volume and the heat quantity of the hot water supplied from the first hot water supply means and the second hot water supply means. In the above program, the computer is caused to execute the following functions: setting the hot water discharge conditions in which the hot water discharge amount of the first hot water supply means is changed in stages by predetermined values; comparing the difference between the discharge temperature of the mixed hot water calculated based on the heat quantity of the hot water discharged from the first hot water supply means and the set temperature of the hot water supply request; and adjusting the hot water discharge amount of the first hot water supply means among the hot water discharge conditions based on this comparison so that the positive and negative values ​​of the difference between the discharge temperature of the mixed hot water and the set temperature are reversed. [Effects of the Invention]

[0018] According to the present invention, any of the following effects can be obtained.

[0019] (1) The heat stored in the tank unit can be effectively utilized, thereby improving hot water supply efficiency. (2) In response to a decrease in the heat storage temperature in the tank unit, the hot water temperature output from the first hot water supply means is reduced, and the hot water supply instruction on the second hot water supply means is set so that the hot water is output at a temperature higher than the set temperature of the hot water supply request, thereby enabling simple and quick hot water supply control in conjunction with the second hot water supply means. (3) When hot water is supplied using both the first hot water supply means and the second hot water supply means, it is possible to maintain hot water supply from the hot water supply system by issuing a hot water supply instruction that adjusts either the hot water supply amount or the hot water supply temperature from the first hot water supply means, or a combination of these, in response to changes in the total hot water supply amount requested. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram showing a hot water supply system according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating the configuration and cooperation functions of a control unit of the hot water supply system. [Figure 3] 10 is a flowchart showing an example of hot water supply control according to the setting of the hot water supply mode. [Figure 4] FIG. 10 is a diagram showing an example of a hot water supply control table. [Figure 5]It is a time chart showing an example of the state of the second hybrid hot water supply mode. [Figure 6] It is a flowchart showing an example of hot water supply control by the hybrid hot water supply mode. [Figure 7] It is a flowchart showing an example of hot water supply control in the second hybrid hot water supply mode. [Figure 8] It is a diagram showing a hot water supply system according to a second embodiment. [Figure 9] It is a flowchart showing an example of hot water supply control according to an example. [Figure 10] It is a flowchart showing an example of setting processing in the second hybrid hot water supply mode. [Figure 11] It is a flowchart showing an example of re-setting processing of hot water supply conditions with respect to fluctuations in the total hot water supply amount. [Figure 12] It is a diagram showing an example of calculation processing of the hot water supply amount and the hot water supply temperature. [Figure 13] It is a diagram showing an example of calculation processing of the hot water supply amount and the hot water supply temperature.

Mode for Carrying Out the Invention

[0021] 〔First Embodiment〕 FIG. 1 shows a hot water supply system according to the first embodiment of the present disclosure. The configuration shown in FIG. 1 is an example, and the technology of the present disclosure is not limited to such a configuration.

[0022] 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 (hereinafter abbreviated as "remote control") 8, etc., and constitutes a multi hybrid hot water supply system used for hot water supply services including stored hot water supply.

[0023] [[ID=4 2]]<HP water heater 4> HP water heater 4 has a heat pump as a first heat source and includes a hot water storage tank that stores heat from hot water heated by the heat source, and is an example of a first hot water supply means of the present disclosure. 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 (hereinafter simply referred to as "tank unit") 12, and an HP control unit 14. In addition, this HP water heater 4 includes means for controlling the outlet hot water temperature and outlet hot water amount, such as a bypass pipe and flow path switching means (not shown).

[0024] The HP unit 10 and the tank unit 12 are provided with a circulation path 16, through which water is supplied from the lower 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 part of the tank unit 12.

[0025] A water supply circuit 18 and a hot water supply circuit 20 are connected to the tank unit 12. When supplying hot water, the tank unit 12 supplies feed water W to a lower portion of the tank unit 12 through the water supply circuit 18, and hot water HW is discharged from an upper portion of the tank unit 12 to the hot water supply circuit 20. Clean water such as tap water is used to supply the feed water W to the water supply circuit 18. In addition, the water supply circuit 18 is equipped with a bypass pipe (not shown) that branches off a portion of the feed water W near the water intake on the bottom side of the tank unit 12 and flows it to the hot water supply circuit 20 side, bypassing the tank unit 12, and a distribution valve that controls the amount of feed water flowing to the bypass pipe and to the tank unit 12 side.

[0026] The HP unit 10 includes a heat pump circuit as a heat source. The heat pump circuit uses, for example, CO2 as a refrigerant and exchanges heat between the heat emitted from the condenser and the supply water. In this HP water heater 4, the supply water W or low-temperature hot water HW extracted from the lower part of the tank unit 12 is heated by heat exchange with the heat emitted 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, where the upper part is high temperature and the lower part is low temperature. The tank unit 12 is equipped with a temperature sensor 22 at a predetermined height on at least the upper side, which detects the stored heat temperature of the hot water HW stored therein. The tank unit 12 may also be equipped with multiple temperature sensors installed at different heights, for example, to monitor the stratification state of the hot water inside.

[0027] The HP control unit 14 is an example of a control unit of the present disclosure, and constitutes a parent unit control unit for the multi-water heater 6, and performs heat storage control of the HP water heater 4 included in the water heating system 2, hot water supply control of the HP water heater 4, and coordinated control between the HP water heater 4 and the multi-water heater 6.

[0028] HP control unit 14 is composed of a computer with communication capabilities, and includes a processing unit, a memory unit, an input / output unit, etc. The processing unit executes the 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 later), and perform cooperative control with multi-hot water heater 6. The memory unit stores the OS and 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 for hot water HW and supply water W, and calculation result information for the mixed temperature.

[0029] The heat storage control of the HP water heater 4 is performed using the HP unit 10 by acquiring temperature information from a temperature sensor 22 disposed in the upper part of the tank unit 12 and monitoring the heat storage temperature of the tank unit 12. The HP water heater 4 also detects the flow rate of the supply water W flowing through the water supply circuit 18 using 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 based on 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 the hot water output from the HP water heater 4 detected by, for example, flow rate sensor 25 and the hot water output detected by 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 based on the heat storage state of the tank unit 12. The hot water output amount in this hot water supply control is determined by the flow rate of hot water output 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. Furthermore, in the hot water supply control, for example, the HP control unit 14 adjusts the opening of a distribution valve (not shown) to control the temperature of hot water coming out of the HP water heater 4 by the ratio between the flow rate flowing from the water supply circuit 18 into the tank unit 12, i.e., the flow rate of hot water coming out of the tank unit 12, and the flow rate flowing from the water supply circuit 18 to the hot water supply circuit 20 via a bypass path (not shown).

[0030] 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 parent water heater and the multi-water heater 6 as the child water heater. This coordinated control includes control of hot water output by either the HP water heater 4 or the multi-water heater 6 operating alone (single hot water output mode), and control of hot water output by the combined operation of the HP water heater 4 and the multi-water heater 6 (hybrid hot water output mode).

[0031] 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 dispensed from HP water heater 4 is equal to or lower than a predetermined value, the individual hot water dispense mode of HP water heater 4 is selected. If the heat storage temperature of tank unit 12 is lower than a predetermined value, the individual hot water dispense mode of multi-water heater 6 is selected. Also, if the heat storage temperature of tank unit 12 is equal to or higher than a predetermined value and the total amount of hot water dispensed for hot water supply requests exceeds a predetermined value, the hybrid hot water dispense mode, which is a combined mode of HP water heater 4 and multi-water heater 6, is selected.

[0032] The hybrid hot water discharge mode of the HP water heater 4 and the multi-water heater 6 includes processes such as monitoring the heat storage temperature of the tank unit 12, monitoring the hot water discharge amount of the HP water heater 4, calculating the mixed temperature based on the hot water discharge temperatures of the HP water heater 4 and the multi-water heater 6, monitoring the mixed temperature using the target hot water discharge temperature (set temperature) set in the remote control 8 as a reference value, controlling the hot water discharge amount and hot water discharge temperature of the HP water heater 4, measuring the amount of water supply flowing into the hot water supply system 2 and monitoring its fluctuations.

[0033] <Multi-water heater 6> The multi-water heater 6 is an example of a second hot water supply means of the present disclosure that burns fuel gas as a second heat source and heats water with the combustion exhaust to generate hot water during hot water supply. This multi-water heater 6 is not limited to one that burns fuel gas as a heat source, but may be any device that uses a heat source other than a heat pump and is capable of generating hot water during hot water supply. This multi-water heater 6 is composed of, for example, a pair of gas water heaters 24-1 and 24-2. These gas water heaters 24-1 and 24-2 are equipped with hot water supply control units 26-1 and 26-2 that control hot water supply based on the hot water supply flow rate and 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, with the HP water heater 4 set as the main unit and the gas water heaters 24-1 and 24-2 set as sub units. Then, the multi-water heater 6 performs hot water supply processing using the gas water heaters 24-1 and 24-2 in accordance with instructions from the HP control unit 14, which is the control means of the parent unit. Furthermore, the multi-water heater 6 may be configured, for example, as a single gas water heater 24-1, or may be configured as a multi-water heater system in which two or more gas water heaters 24-1, 24-2, . . . are provided in parallel.

[0034] Each gas water heater 24-1, 24-2 is a device that supplies hot water to the hot water supply load side, for example, using a gas boiler (GB) that heats water using 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 each gas water heater 24-1, 24-2. In other words, when the multi-water heater 6 is operating independently or in cooperation with the HP water heater 4, it will supply hot water using only one of the gas water heaters 24-1, 24-2 depending on the hot water demand, or both will be operated in conjunction with each other to supply hot water.

[0035] Hot water supply control units 26-1 and 26-2, together with HP control unit 14, are an example of a control unit of the present disclosure, and constitute a control unit of a slave unit for HP control unit 14. These hot water supply control units 26-1 and 26-2 are configured by a computer with a communication function, similar to HP control unit 14, and include a processing unit, a memory unit, an input / output unit, etc.

[0036] The multi-water heater 6 controls the hot water supply of each gas water heater 24-1, 24-2 and performs coordinated control linking the gas water heaters 24-1, 24-2 based on hot water supply control commands from the HP control unit 14, which is set as the parent unit of the hot water supply means. This hot water supply control includes control of the hot water outlet temperature and amount of hot water supplied by each gas water heater 24-1, 24-2. The coordinated control also includes control such as selecting the gas water heater 24-1 if the amount of hot water supplied by the multi-water heater 6 in response to a hot water supply request to the hot water supply system 2 is less than the hot water supply capacity of the gas water heater 24-1, and selecting the gas water heater 24-2 to supply the excess amount of hot water if the amount of hot water supplied exceeds the hot water supply capacity of the gas water heater 24-1.

[0037] <Remote Control 8> Remote control 8 is connected in a state that allows transmission and reception of control information to and from HP control unit 14, which is the control unit of the parent unit, and is used to remotely control HP control unit 14 and hot water supply control units 26-1 and 26-2. Remote control 8 is equipped with a computer that communicates with HP control unit 14 and performs startup control of hot water supply control units 26-1 and 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 hot water outlet amount of HP control unit 14 and / or hot water supply control units 26-1 and 26-2.

[0038] In addition, hot water supply system 2 may be provided with a temperature sensor 27 that detects the hot water outlet temperature to a hot water outlet load (not shown), for example, on hot water supply circuit 20, downstream of multi-water heater 6. This allows HP control unit 14 to monitor, for example, whether the hot water outlet temperatures set for HP water heater 4 and multi-water heater 6, and the hot water discharged and mixed at the hot water supply flow rate set for HP water heater 4, match the set temperature of the hot water supply request or are within a predetermined range. If the hot water outlet temperature detected by temperature sensor 27 differs from the set temperature of the hot water supply request by more than the predetermined range, HP control unit 14 may perform a correction process for the hot water supply control of HP water heater 4 and multi-water heater 6.

[0039] <Control function of hot water supply system 2> Fig. 2 shows the configuration and cooperation functions of the control unit of the hot water supply system. The configuration shown in Fig. 2 is one example.

[0040] 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 functions as a processing unit of the hot water supply system 2 by executing the arithmetic processing of the OS and the hot water supply control program stored in the memory unit 32. The memory unit 32 functions as a storage unit that stores, for example, programs and detected values ​​of the temperature sensors 22 and 27 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 unit 26-1, and may be capable of communication processing via wired or wireless means, or other means such as near-field infrared communication. Input / output unit 36 ​​is an example of an interface that enables the transmission of control instructions and the reception of detected information between each functional unit of HP water heater 4. Input / output unit 36 ​​receives detected information such as the detected temperature inside tank unit 12 from temperature sensor 22, the water supply amount and hot water output amount from flow sensors 23 and 25, and the hot water output temperature from temperature sensor 27. Input / output unit 36 ​​also outputs instructions for heat storage operation generated by a processing unit such as processor 30 to HP unit 10 or a pump or the like installed on circulation path 16 (not shown).

[0041] 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 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 that store, for example, programs, the inlet water temperature detected by the temperature sensors 46-1, 46-2 installed in each gas water heater 24-1, 24-2, the temperature after heating detected by the temperature sensors 48-1, 48-2, and the outlet water temperature detected by the 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 the flow sensors 52-1, 52-2, and also function as a work area for the processors 38-1, 38-2 to perform calculations. The communication units 42-1 and 42-2 are examples of functional units that send and receive information and control instructions between the remote control 8 and the HP control unit 14, and may be any units capable of communication processing via wired or wireless means, or other means such as near-field infrared communication. Input / output units 44-1 and 44-2 are an example of an interface that enables the transmission of control instructions and the reception of detection information between each functional unit of multi-water heater 6. Input / output units 44-1 and 44-2 are connected to, for example, temperature sensors 46-1, 46-2, 48-1, 48-2, 50-1, and 50-2, and also output combustion control instructions from processors 38-1 and 38-2 to heat source units 51-1 and 51-2.

[0042] <Hot water mode selection setting> We will now explain the hot water supply mode set in the hot water supply system 2. This hot water supply mode is selected from among HP hot water supply mode, hybrid hot water supply mode, and multi-hot water supply mode depending on the heat storage and / or hot water supply amount of the tank unit 12.

[0043] In the HP water heater only hot water supply mode, only the HP water heater 4 is operated and hot water is supplied to meet the hot water demand. At this time, the multi-water heater 6 is in a sleep 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 supply W is supplied from the HP water heater 4 at the set temperature or a temperature within a predetermined temperature range including the set temperature. In addition, while supplying hot water, the HP water heater 4 stores heat in the tank unit 12.

[0044] In addition, the hybrid hot water supply mode is a hot water supply operation process that operates, for example, the HP water heater 4 and the multi-water heater 6 to supply hot water in response to hot water demand. In this mode, water supply W is supplied to the multi-water heater 6 and also to the tank unit 12. The hot water output from the HP water heater 4 and the multi-water heater 6 merge in the hot water supply circuit 20, and hot water HW is supplied at the set temperature or a mixed temperature adjusted within a certain range including the set temperature. Here, the number of gas water heaters 24-1 and 24-2 in operation and the devices to be operated are set according to the hot water demand. For example, if the hot water demand does not exceed the hot water output capacity of the gas water heater 24-1, only the gas water heater 24-1 is operated. If the hot water demand exceeds the hot water output capacity of the gas water heater 24-1, both the gas water heaters 24-1 and 24-2 are operated. Furthermore, the HP water heater 4 that is discharging hot water performs a heat storage operation in the tank unit 12. This hybrid hot water discharge mode includes, for example, a first hybrid hot water discharge mode, which is a hot water discharge mode with high-temperature heat storage control that is selected when the heat storage temperature in the HP water heater 4 is sufficiently high for the hot water supply request and the total amount of hot water required is large, and a second hybrid hot water discharge mode, which is a hot water discharge mode with low-temperature heat storage control that is selected when the heat storage temperature in the HP water heater 4 has dropped below the hot water supply request.

[0045] When the first hybrid hot water supply mode is set, the hot water supply system 2 controls, for example, the HP water heater 4 that supplies hot water at the set temperature and flow rate threshold of the hot water demand to bear part of the hot water supply load, and the multi-water heater 6 to bear the remaining load. 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.

[0046] When the second hybrid hot water supply mode is set, hot water supply system 2 adjusts the amount and temperature of hot water output 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 hot water demand, and controls the shortfall by outputting hot water from multi-water heater 6. In this hot water supply control of HP water heater 4, for example, based on the heat quantity calculated from the temperature and flow rate of the hot water demand and the hot water output temperature and heat quantity that can be supplied by tank unit 12, the amount of hot water output from HP water heater 4 is reduced to a predetermined range and the hot water output temperature is set to a temperature lower than the temperature of the hot water demand, thereby controlling to use as much of the heat stored in tank unit 12 as possible.

[0047] In the multi-water heater sole hot water supply mode, the hot water supply system 2 operates, for example, only the multi-water heater 6, and hot water is supplied to meet the hot water demand. At this time, the hot water 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 hot water W, and hot water HW is supplied from the multi-water heater 6 at a set temperature or a temperature within a predetermined temperature range including the set temperature. Here, 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 will operate. At this time, the HP water heater 4, which is disconnected from the hot water supply, operates the HP unit 10 and stores heat in the tank unit 12 under normal conditions.

[0048] <Hot water control> Fig. 3 shows an example of a process for controlling hot water supply. The process contents and procedure shown in Fig. 3 are merely an example, 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).

[0049] 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 change.

[0050] Heat accumulation determination step (S102): The HP control unit 14 determines the calculated heat accumulation state. This heat accumulation determination determines whether the upper layer temperature of the tank unit 12 is higher than a threshold temperature, which is the lower limit. In this case, it determines whether the temperature information acquired from the temperature sensor 22 installed at a predetermined height position of the tank unit 12 is within a temperature range suitable for hot water supply. Therefore, if the upper layer temperature of the tank unit 12 is below the threshold temperature (NO in S102) and there is no heat accumulation, the system transitions to the multi-water heater single hot water supply mode (S109), and if the upper layer temperature is higher than the threshold temperature (YES in S102) and there is heat accumulation, the HP control unit 14 executes the heat accumulation determination step (S103) for the hot water supply request.

[0051] Heat storage determination step (S103): To determine whether the hot water HW in tank unit 12 is at a temperature that can meet the hot water supply request, HP control unit 14 determines whether the temperature information acquired from temperature sensor 22 is higher than the remote control set temperature, which is the target temperature for 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 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 detecting the hot water output amount of HP water heater 4 (S104).

[0052] Hot water output amount detection step (S104): In this hot water output amount detection step, the flow rate sensor 25 detects the amount of hot water HW output from the tank unit 12, and the HP control unit 14 obtains flow rate information from the flow rate sensor 25.

[0053] Hot water output determination step (S105): HP control unit 14 monitors the change in the hot water output rate of HP water heater 4 and determines whether the hot water output rate 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 rate on the HP water heater 4 side is equal to or less than the flow rate threshold (YES in S105), the system transitions to HP water heater only hot water output mode (S106), and if the hot water output rate exceeds the flow rate threshold (NO in S105), the system transitions to first hybrid hot water output mode (S107) as heat storage high temperature control.

[0054] HP water heater sole hot water supply mode (S106): This HP water heater sole hot water supply mode is an example of the sole hot water supply mode selection process of the present disclosure. That is, in this mode, there is heat storage necessary for hot water supply from tank unit 12, so hot water is supplied only using HP water heater 4. At this time, multi-water heater 6 is in a sleep state.

[0055] 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 is met by sharing 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 reduce the operating rate of the multi-water heater 6.

[0056] 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 heat storage temperature within the tank unit 12 is not sufficient to supply hot water at the set temperature of the hot water supply request, 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 heat stored 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 storage in the tank unit 12 and to reduce the operating rate of the multi-water heater 6.

[0057] 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. In other words, in this mode, there is no heat storage required to supply hot water from the tank unit 12, so hot water is supplied using only the multi-water heater 6. At this time, the HP water heater 4 stops supplying hot water and performs heat storage operation for the tank unit 12.

[0058] <About hot water supply control table 60> FIG. 4 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, for example, has an HP water heater information section 61, a multi-water heater information section 62, and a mixed hot water discharge capacity section 63 vertically, and also has a hot water discharge amount information section 64 and a hot water discharge temperature information section 65 horizontally. Then, in the hot water supply control, the heat quantity is calculated using the hot water output amount information and hot water output temperature information input into hot water supply control table 60, for example, and the hot water output capacity of HP water heater 4 and multi-water heater 6 is adjusted based on this heat quantity, and a hot water output instruction is generated. Specifically, HP control unit 14 calculates the total hot water output amount A+B by combining the hot water output amount A of HP water heater 4 and the hot water output amount B of multi-water heater 6, and the hot water output temperature X from HP water heater 4 and the hot water output temperature Y from multi-water heater 6 are input. Then, in the hot water supply control, the hot water output temperature after mixing is calculated based on the hot water output amount and hot water temperature input into hot water supply control table 60. This calculation of the hot water output temperature is performed, for example, using the following formula. (Outlet water temperature) = [(A × X) + (B × Y)] / (A + B) (1) In hot water supply control, for example, this hot water outlet temperature can be set as the set temperature of the hot water supply request input into the remote control 8, and by back-calculating equation (1), either the hot water output amount or the hot water outlet temperature from the HP water heater 4 or multi-water heater 6, or both, can be calculated, and the hot water supply process can be performed.

[0059] In hot water supply control, for example, the hot water output conditions are set as follows: hot water output amount A of HP water heater 4, hot water output amount B of multi-water heater 6, and hot water output temperature Y of multi-water heater 6; and hot water output temperature X of HP water heater 4 is set within a predetermined range; the hot water output temperature after mixing is calculated based on the calorific value; and it is determined whether this calculated hot water output temperature matches the set temperature of the hot water supply request. If the calculated hot water output temperature is not within a predetermined range for the set temperature of the hot water supply request, HP control unit 14 may vary the hot water output temperature X of HP water heater 4.

[0060] Furthermore, in the hot water supply control, for example, when hot water supply is continuing in hybrid hot water supply mode, if the water supply amount changes by increasing or decreasing the opening of a water valve (not shown), i.e., if the total hot water supply amount requested for hot water supply changes, HP control unit 14 transitions to a process for resetting the water supply conditions. This water supply amount is the total hot water supply amount flowing from hot water supply system 2 to the hot water supply load side, and the water supply status is monitored by flow sensor 23 installed on water supply circuit 18. Alternatively, the water supply status may be monitored by flow sensor 25 installed on HP water heater 4 and flow sensors 52-1 and 52-2 installed on gas water heaters 24-1 and 24-2. In this water supply condition resetting process, for example, the hot water supply control table 60 is used to maintain the hot water output volume A of the HP water heater 4 and the hot water output temperature Y of the multi-water heater 6 at the set values ​​before the water supply volume changed, and then a heat calculation is performed based on the hot water output volume and hot water output temperature of the HP water heater 4 and the multi-water heater 6. In the process of resetting the water supply conditions, the HP control unit 14 sets the outlet hot water temperature X within a predetermined limit range relative to the hot water output A of the HP water heater 4 before the hot water output change, and determines the hot water output B of the multi-hot water heater 6 by subtracting the hot water output A from the total hot water output. The outlet hot water temperature Y of the multi-hot water heater 6 is not changed from before the hot water output change, but is maintained at a predetermined temperature higher than the remote control setting temperature, which is the hot water supply request. The HP control unit 14 also calculates the outlet hot water temperature after mixing using a heat quantity calculation process that uses these hot water supply conditions. It then determines whether this calculated outlet hot water temperature matches the remote control setting temperature or is within a predetermined range. If this outlet hot water temperature differs significantly from the remote control setting temperature, the HP water heater 4's outlet hot water temperature is adjusted. If this adjustment of the outlet hot water temperature does not match the remote control setting temperature, the HP control unit 14 adjusts the hot water output A. If this adjustment of the outlet hot water temperature does not match the remote control setting temperature, the HP control unit 14 adjusts the hot water output A.

[0061] <About hybrid hot water mode> Figure 5 shows an example of the state of the second hybrid hot water discharge mode. The state changes and processing execution timing shown in Figure 5 are examples, and the present invention is not limited to such a configuration. In Figure 5, the horizontal axis shows the passage of time, and the vertical axis shows the amount of hot water discharged and the hot water temperature, respectively.

[0062] For example, when the heat storage temperature in tank unit 12 is low relative to 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 to supply hot water to make up for the shortage of heat. The hot water supply process shown in Figure 5 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 an example of processing when the total hot water output required for hot water supply is small, for example, about 8 L / min, or when the hot water output from HP water heater 4 is increased.

[0063] 5, 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 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 supply mode and outputs a hot water supply instruction to multi-water heater 6.

[0064] At this time, the HP control unit 14 generates, for example, a hot water supply control table 60, and sets the hot water supply condition to a setting value that reduces the hot water supply volume on the HP water heater 4 side to within a predetermined range, as well as setting the set temperature for the hot water supply request and the total hot water supply volume, which is the water supply volume detected by the flow sensor 23, and from this information calculates each setting value for the hot water supply temperature on the multi-water heater 6 side, the hot water supply temperature and hot water supply volume from the HP water heater 4, etc., so as to utilize as much of the heat stored in the tank unit 12 as possible, and also sets the number of gas water heaters 24-1 and 24-2 in operation and the equipment to be operated. 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 volume from the gas water heater 24-1 or the gas water heater 24-2 at time t3 is equal to the total hot water supply volume minus the hot water supply volume from the HP water heater 4, so the actual hot water supply temperature, which is the mixed temperature of the hot water supplied from the HP water heater 4 and the hot water supplied from the gas water heater 24-1 or the gas water heater 24-2, can be adjusted to be the same as the set temperature of the hot water supply request or within a specified range.

[0065] In addition, in the hot water supply process, if a hot water supply request occurs, for example, at time t1, hot water supply may be started using the HP water heater 4 alone or the HP water heater 4 in combination with the gas water heater 24-1, regardless of whether the heat storage temperature in the tank unit 12 is higher than the set temperature of the hot water supply request.

[0066] After time t3, HP control unit 14 collects information on the detected amount of hot water supplied during hot water supply in the second hybrid hot water supply mode and monitors whether there is any change in the total amount of hot water supplied. If there is a change in the amount of hot water supplied, HP control unit 14 executes a process to reset the hot water supply conditions, such as the hot water supply temperature of HP water heater 4 and the hot water supply amount from gas water heaters 24-1, 24-2, etc., while maintaining the hot water supply amount of HP water heater 4 and the hot water supply temperature of gas water heaters 24-1, 24-2, etc., as described above.

[0067] <Hot water control> Figure 6 shows an example of hot water supply control in hybrid hot water supply mode. The process content and process procedure shown in Figure 6 are one example, and the technology of the present disclosure is not limited to such a configuration. Furthermore, the process content shown here is one example of the hot water supply method and hot water supply program of the present disclosure.

[0068] This hot water supply control shows an example of processing when, for example, in the hot water supply control of Figure 3, 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 Figure 6, a flow rate determination (S201), a heat storage determination process (S202), setting the first hybrid hot water supply mode (S203), hot water supply control (S204), determining the passage of time (S205), and setting the second hybrid hot water supply mode (S206).

[0069] Flow rate determination (S201): The HP control unit 14 is in a standby state until it acquires a flow rate detection from the flow rate sensor 23 (NO in S201), and when the water supply W is detected by the flow rate sensor 23 due to opening the hot water tap, etc. (YES in S201), it 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 in the tank unit 12. In this heat storage determination, 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 supply mode (S203), and transitions to hot water supply control (S204). Setting first hybrid hot water supply mode (S203): The HP control unit 14 sets the hot water supply temperature of the HP water heater 4 and the multi-water heater 6 to the set temperature of the hot water supply request, causes the HP water heater 4 to supply hot water at the flow rate threshold, and causes the hot water supply multi-water heater 6 to make up for any shortfall in the hot water supply amount in response to the hot water supply request. Hot water supply control (S204): The HP control unit 14 outputs the hot water outlet temperature and hot water outlet amount set in the hot water supply control table 60 to the HP hot water heater 4 and the hot water outlet temperature to the multi-hot water heater 6, thereby performing hot water supply using heat storage high temperature control.

[0070] Determining time elapse (S205): If the temperature of the upper layer inside the tank unit 12 is equal to or lower than the remote control set temperature (YES in S202), the HP control unit 14 waits until a standby time tm, for example, 3 seconds, 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. Once the standby time tm has elapsed, the process proceeds to determining the temperature of the upper layer inside the tank unit 12 (S206). Setting second hybrid hot water outlet mode (S206): HP control unit 14 sets the hot water outlet amount of HP water heater 4 to the minimum hot water outlet amount, for example as part of the hot water outlet conditions in hot water supply control table 60, and sets the hot water outlet temperature to a value within a predetermined range and lower than the remote control set temperature, and causes hot water to be dispensed. HP control unit 14 also issues instructions to hot water supply control units 26-1, 26-2 to execute hot water supply processing in the second hybrid hot water outlet mode, and generates and outputs hot water outlet instructions such as the remote control set temperature and the hot water outlet temperature to be set in multi-water heater 6.

[0071] <Hot water supply process in the second hybrid hot water supply mode> Figure 7 shows an example of hot water supply control in the second hybrid hot water supply mode. The process content and process procedure shown in Figure 7 are one example, and the technology of the present disclosure is not limited to such a configuration. Furthermore, the process content shown here is one example of the hot water supply method and hot water supply program of the present disclosure.

[0072] This hot water supply control includes, for example, a temperature determination process (S301), a hot water outlet condition setting process (S302), a process for setting the hot water outlet temperature of the HP water heater (S303), a hot water outlet process (S304), a process for monitoring fluctuations in the total hot water output (S305), a hot water outlet condition resetting process (S306), and a process for canceling the second hybrid hot water outlet mode (S307).

[0073] Temperature determination step (S301): The HP control unit 14 acquires the temperature detected by the temperature sensor 22 and determines whether the temperature of the upper portion of the tank unit 12 is higher than a threshold temperature Ts, for example, 45°C. This threshold temperature = 45°C is the temperature at which hot water can be dispensed in the second hybrid hot water supply mode, for example, within the set threshold temperature Ts or a temperature range including the threshold temperature, and is an example of the heat storage regulation temperature condition of the present disclosure. Note that in the hot water supply process, the threshold temperature is not limited to 45°C. If the upper temperature is greater than 45°C (YES in S301), the HP control unit 14 determines that this is the heat storage temperature required to execute the second hybrid hot water discharge mode in the tank unit 12, and proceeds to the hot water discharge condition setting process (S302).

[0074] Hot water discharge condition setting process (S302): The HP control unit 14 sets hot water discharge conditions for the HP water heater 4 and the multi-water heater 6 in the second hybrid hot water discharge mode. For example, these hot water discharge conditions include setting the amount of hot water discharged from the HP water heater 4 to the minimum amount, and setting hot water discharge conditions for the multi-water heater 6 to make up for the shortfall in hot water temperature and amount in response to the hot water supply request. For example, the hot water discharge conditions for the multi-water heater 6 set the hot water discharge temperature to a predetermined temperature, for example, 5°C higher than the temperature set on the remote control 8. This hot water discharge temperature may be increased or decreased depending on, for example, the difference between the hot water discharge temperature on the HP water heater 4 side and the temperature set on the remote control 8, the amount of hot water discharged from the HP water heater 4, etc. The setting process of these hot water discharge conditions is performed using hot water supply control table 60, and the set hot water discharge conditions become hot water supply instructions on the multi-water heater 6 side.

[0075] Setting the outlet temperature of the HP water heater (S303): As already described using Figure 4, the HP control unit 14 compares the amount of hot water discharged from the HP water heater 4 and the calculated value of the outlet temperature after mixing calculated using the hot water discharge instruction to the multi-water heater 6 to see if they match the set temperature of the hot water supply request or are within a specified range, and calculates and sets the outlet temperature of the HP water heater 4 based on the comparison result.

[0076] Hot water supply process (S304): As a hot water supply process in the second hybrid hot water supply mode, the hot water supply system 2 supplies hot water using both the HP hot water heater 4 and the multi-hot water heater 6 according to the set HP hot water supply temperature and hot water supply instruction, and performs hot water supply using heat storage low temperature control. After hot water supply starts and during second hybrid hot water supply, the HP control unit 14 executes S301 at a predetermined timing and monitors the heat storage temperature in the tank unit 12, thereby repeatedly determining whether to continue hot water supply.

[0077] Process for monitoring fluctuations in total hot water output (S305): When hot water output begins in the second hybrid hot water output mode, the HP control unit 14 collects detection information from the flow sensor 23 at predetermined intervals or continuously, or automatically collects the detection values ​​when there is a flow rate fluctuation, and monitors the flow rate of the supply water W flowing into the water supply circuit 18. Then, when the HP control unit 14 confirms a fluctuation in the total hot water output based on the collected detection values ​​(YES in S305), it proceeds to a process for resetting the hot water output conditions (S306). This monitoring process allows hot water to be supplied at a temperature corresponding to the hot water supply request set on the remote control 8 in response to changes in the opening degree of the hot water tap, etc.

[0078] Hot water discharge condition resetting process (S306): The HP control unit 14 resets the hot water discharge conditions as a correction process when the total hot water discharge volume of the hot water supply request changes. The HP control unit 14 activates the hot water supply control table 60 and sets the hot water discharge conditions, such as the hot water discharge temperature and hot water discharge volume set in the HP water heater 4. It also calculates and sets the hot water discharge temperature and hot water discharge volume of the HP water heater 4 using the changed total hot water discharge volume and the remote control setting temperature. That is, in this resetting process, for example, in response to a hot water discharge command for the hybrid hot water supply mode set previously, the HP water heater 4 adjusts the set values ​​for the hot water discharge volume and hot water temperature from the HP water heater 4 and determines whether these set values ​​allow hot water to be discharged at the remote control setting temperature, which is the hot water discharge volume and hot water temperature corresponding to the hot water supply request. If this determination indicates that the hot water supply request cannot be met, the HP water heater 4 adjusts the hot water discharge volume and hot water temperature and adjusts the hot water discharge conditions to correspond to the hot water supply request by calculating the heat amount. If the HP control unit 14 determines that the temperature matches the remote control setting or that hot water is being dispensed within a predetermined range, the process returns to S301 and the heat storage state of the tank unit 12 is repeatedly monitored.

[0079] Step of canceling second hybrid hot water discharge mode (S307): When the heat storage in tank unit 12 becomes insufficient and the upper layer temperature falls below the set threshold temperature Ts (NO in S301), HP control unit 14 determines that hot water supply using HP water heater 4 is impossible and cancels control of the second hybrid hot water discharge mode that is currently being executed. By canceling this second hybrid hot water discharge mode, the process returns to S201 in FIG. 6 or S101 in FIG. 3.

[0080] <Advantages of the First Embodiment> According to this configuration, 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 by setting a multi-stage hybrid hot water supply mode depending on the temperature and flow rate conditions of the hot water supply request, the heat stored in the HP water heater 4 can be utilized as effectively as possible. (2) By effectively utilizing the heat stored in the HP water heater 4, the energy efficiency of the water heater system 2 can be improved.

[0081] (3) By monitoring the decrease in the heat storage temperature in the tank unit 12 and immediately operating the multi-water heater 6 to compensate for the lack of heat when the heat storage temperature drops, hot water can be supplied at a temperature and flow rate that meets the hot water supply demand. (4) Even if the total amount of hot water dispensed fluctuates while dispensing hot water in the second hybrid hot water dispense mode, By issuing a hot water supply instruction that adjusts either the amount of hot water output or the temperature of hot water output from the HP hot water heater 4, or a combination of these, the hot water supply system 2 can continue to supply hot water. (5) By resetting the hot water discharge conditions in this way in response to fluctuations in the total hot water discharge volume, it is possible to easily and quickly discharge hot water at a temperature and flow rate that corresponds to the hot water supply demand.

[0082] Second Embodiment Fig. 8 shows a hot water supply system according to a second embodiment. The configuration shown in Fig. 8 is an example, and the technology of the present disclosure is not limited to such a configuration. In Fig. 8, the same parts as those in Fig. 1 are given the same reference numerals, and detailed description thereof will be omitted.

[0083] This hot water supply system 70 includes a solar tank unit 72 as first hot water supply means. This solar tank unit 72 is a means for heating hot water or water in the tank unit 12 using heat collected by a solar heat collector 74 (hereinafter referred to as "heat collector 74") as a first heat source to supply hot water. This heat collector 74 is an example of heat exchange means for collecting solar heat applied from the outside and exchanging that heat (calorie) with a heat medium HM circulating inside. Between the tank unit 12 and the solar collector 74, there is provided a solar heat collection circuit 76 (hereinafter referred to as the "heat collection circuit 76") with a sealed interior, and the heat collected by the solar collector 74 is heat-exchanged with the hot water or water in the tank unit 12 through a heat medium HM circulated inside the circuit. The heat medium HM may be water, or antifreeze or other liquid that is less susceptible to changes in the outside air temperature. The heat collection circuit 76 is equipped with a circulation pump 78 for circulating the heat medium HM inside the sealed interior, and a heat exchange section 80 for exchanging heat between the heat medium HM and the hot water or water in the tank unit 12 is formed in a part inserted inside the tank unit 12 or in a part adjacent to the tank unit 12. The circulation pump 78 is an example of a pumping means for causing the heat medium HM to flow between the heat collector 74 and the heat exchange section 80. This circulation pump 78 is, for example, a pump using a DC (direct current) motor, and may be provided with a backflow prevention function that prevents the heat medium HM from flowing backward when the pump is stopped.

[0084] The solar tank unit 72 is equipped with a control unit 82, which not only monitors the heat storage state within the tank unit 12, but also acquires detected temperature information from temperature sensors 84, 86 installed in the heat collection circuit 76 to monitor the temperature T1 of the heat medium HM before heat exchange in the heat exchange unit 80 and the temperature T2 of the heat medium HM returning to the heat collector 74 after heat exchange, thereby controlling the heat storage operation of the tank unit 12. The control unit 82 is also an example of a control unit for the hot water supply system 70 of the present disclosure, and, like the HP control unit 14 described above, constitutes the master unit control means for the multi-water heater 6, and performs hot water supply control of the solar tank unit 72 and hot water supply coordination control of the solar tank unit 72 and the multi-water heater 6 in hybrid hot water supply mode. This control unit 82 is configured by a computer equipped with, for example, a processor, memory, communication unit, etc. (not shown), and executes an OS for operating the solar tank unit 72 and the hot water supply control program of the present disclosure, as well as heat storage control for storing heat collected by the heat collector 74 in the tank unit 12. The control unit 82 is connected to the remote control 8 by wire or wirelessly, and, like the HP control unit 14 described above, acquires heat storage information such as the temperature detected by the temperature sensor 22, calculates the hot water outlet temperature, performs hot water supply control (described later), and performs cooperative control with the multi-hot water heater 6.

[0085] The control unit 82 receives temperatures T1 and T2 from temperature sensors 84 and 86, for example, and performs heat collection control, such as driving the circulation pump 78. To control the circulation pump 78, for example, a rotation speed table for the circulation pump 78 may be used, as drive control information (not shown), in which the rotation speed is set at multiple stages based on the states of temperatures T1 and T2 of the heat medium HM and the temperature inside the tank unit 12. The control unit 82 may then monitor, for example, the amount of heat applied to the heat collector 74, i.e., the amount of heat exchanged with the heat medium HM, and the temperature inside the tank unit 12, to control the rotation of the circulation pump 78 and control the flow rate of the heat medium HM.

[0086] <Heat collection control> In the solar tank unit 72, steps of the heat collection process for storing heat in the tank unit 12 include, for example, a heat collection start operation, a heat storage operation, a heat collection execution decision operation, and a heat collection stop operation. As the heat collection start operation, the control unit 82 determines whether heat collection is possible by, for example, determining whether it is within the set time period, i.e., the time period when the sun is out, and whether the temperature of the heat medium HM after heat exchange in the heat collector 74, which is the temperature detected by the temperature sensor 84, is higher than the temperature detected by the temperature sensor 22 in the tank unit 12. Next, the control unit 82 starts the circulation pump 78 as a heat storage operation and circulates the heat medium HM so that the temperature inside the tank unit 12 does not become higher than the temperature of the heat medium HM, thereby storing the recovered solar heat in the tank unit 12. As a heat collection execution determination operation, the control unit 82 monitors the state of solar heat collection by the heat collector 74 and compares the hot water temperature in the tank unit 12 with the temperature of the heat medium HM to determine whether heat collection is successful. As a heat collection stopping operation, the control unit 82 stops the circulation pump 78 and stops the heat collection process when the heat collector 74 is not in a state where it can collect solar heat, or depending on the temperature comparison result between the hot water and the heat medium HM in the tank unit 12, etc.

[0087] In this heat collection control, the control unit 82 sets a predetermined threshold temperature, for example, for the temperature of the heat medium HM and the detected temperature of the hot water in the tank unit 12, or the difference between these detected temperatures, and adjusts the operating rotation speed of the circulation pump 78 depending on whether or not the threshold temperature has been reached, and may also perform control such as intermittent operation in which the circulation pump 78 is repeatedly started and stopped.

[0088] <Hot water control> The control unit 82 controls the hot water supply of the hot water supply system 70, and performs hot water supply processing such as a single hot water supply mode in which hot water is supplied only by the solar tank unit 72, a first hybrid hot water supply mode in which the solar tank unit 72 and the multi-water heater 6 are used together when there is sufficient heat stored in the tank unit 12, or a second hybrid hot water supply mode in which the solar tank unit 72 and the multi-water heater 6 are used together when there is little heat stored in the tank unit 12. The determination and control processing of these hot water supply modes can be performed by performing processing similar to the previously described steps S101 to S109 (Fig. 3), steps S201 to S206 (Fig. 6), and steps S301 to S307 (Fig. 7).

[0089] <Effects of the second embodiment> According to this configuration, one of the following effects can be obtained. (1) The same effects as those of the first embodiment can be obtained. (2) By using solar heat as the heat source for the first hot water supply means, the environmental load can be reduced and natural energy can be used effectively. (3) The operation of the circulation pump 78 is controlled based on the state of heat storage in the tank unit 12 and the state of solar heat collection, thereby preventing the pump from operating unnecessarily, thereby achieving energy savings. [Example]

[0090] Next, an embodiment of hot water supply control will be described. Figure 9 shows an example of hot water supply control, Figure 10 is a flowchart showing an example of the setting process for the second hybrid hot water discharge mode, and Figure 11 shows an example of the resetting process for the hot water discharge conditions in response to fluctuations in the total hot water discharge amount. Also, Figures 12 and 13 show an example of the calculation process for setting and resetting the hot water discharge conditions.

[0091] HP control unit 14 monitors the operation of remote control 8 from, for example, a standby state (S401), and if remote control 8 operates (YES in S401), monitors whether a flow rate has occurred in hot water supply system 2 (S402). In hot water supply system 2, for example, before a flow rate is generated (NO in S402), the set temperatures on the HP water heater 4 and multi-water heater 6 sides are set to a hot water supply request temperature, for example, 60°C, and the hot water output rates of HP water heater 4 and multi-water heater 6 are both 0 L / min. Then, in hot water supply system 2, when a flow rate is generated (YES in S402), the hot water output rate of HP water heater 4 changes from 0 L / min to 15 L / min, and the hot water output rate of multi-water heater 6 changes from 0 L / min to 30 L / min. These hot water output rates, for example, are such that a total hot water output rate of 45 L / min flowing through the water supply circuit as a hot water supply request flows into HP water heater 4 at the set flow rate, and the remainder flows into multi-water heater 6.

[0092] 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 equal to or lower than the temperature set by the remote control (S403), and if the result of the determination is equal to or lower than the temperature set by the remote control (YES in S403), the HP control unit 14 proceeds to determine whether the heat stored in the tank unit 12 can be used for hot water supply, and sets the hot water output rate on the HP water heater 4 side to 0 [L / min], resulting in the hot water output rate on the multi-water heater 6 side being 45 [L / min]. In other words, the hot water output rate on the multi-water heater 6 side is set to be equal to the total hot water output rate of the hot water supply request, and the unit is in standalone operation.

[0093] After waiting for a predetermined time, for example, 3 seconds, during which hot water is being discharged from the multi-water heater 6 alone, HP control unit 14 determines whether the temperature of the upper layer of tank unit 12 is higher than a threshold temperature, for example, 45°C (S405). If the temperature of the upper layer of tank unit 12 is higher than the threshold temperature (YES in S405), 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 (S406), and calculates and sets the hot water discharge conditions for HP water heater 4 to supply hot water. Furthermore, while supplying hot water in the second hybrid hot water outlet mode, HP control unit 14 monitors flow rate fluctuations in water supply circuit 18 (S407), and if there is a flow rate fluctuation (YES in S407), immediately proceeds to a process (S408) of resetting the hot water outlet temperature of HP water heater 4 as a reset of the hot water outlet conditions. After the start of the hot water supply process, HP control unit 14 then repeatedly executes processes, for example, from monitoring the heat storage state in tank unit 12 (S405) to resetting the hot water outlet temperature in response to flow rate fluctuations (S408).

[0094] Furthermore, if the temperature of the upper layer of tank unit 12 is not higher than the threshold temperature (NO in S405), HP control unit 14 determines that the heat storage temperature is not high enough to execute the second hybrid hot water discharge mode, and sets the second hybrid hot water discharge mode to OFF (S409). In this case, HP control unit 14 may set the single hot water discharge mode by multi-water heater 6, for example.

[0095] <Second hybrid hot water outlet mode> In this setting process, for example, as shown in Figure 10, when the second hybrid hot water outlet mode is set to ON (S406), the post-mixing hot water outlet temperature calculation process (S501) is executed, the hot water outlet conditions corresponding to the hot water supply request are determined, and these are set as hot water supply instructions to the HP water heater 4 or the multi-water heater 6. When the HP control unit 14 generates the hot water supply control table 60, for example as shown in A of Figure 12, and sets the hot water output rate on the HP water heater 4 side to a fixed value of, for example, 3 [L / min], the hot water output rate of the multi-water heater 6 becomes 42 [L / min], which is the total hot water output rate of 45 [L / min] minus 3 [L / min]. In this case, the HP control unit 14 can select the number of gas water heaters 24-1, 24-2, ... and the equipment to be operated, depending on the hot water output rate.

[0096] Furthermore, HP control unit 14 sets the hot water outlet temperature on multi-water heater 6, which dispenses high-temperature hot water, to 65°C, calculated as the remote control set temperature + 5°C, which is the hot water supply request, and selects three temperatures within the limited range of 25°C to 45°C for HP water heater 4. The set temperature for HP water heater 4 may be, for example, a single temperature, or three or more temperatures may be set. Then, HP control unit 14 uses the hot water outlet conditions of selected HP water heater 4 and multi-water heater 6 to calculate the expected hot water outlet temperature after mixing based on the calorific value calculation process as shown in equation (1) (S501). As shown in A of Fig. 12, for the three types of hot water outlet temperatures for HP water heater 4, 25 [°C], 35 [°C], and 45 [°C], the expected hot water outlet temperatures after mixing, from lowest to highest, are 62.3 [°C], 63.0 [°C], and 63.7 [°C], respectively.

[0097] Next, the HP control unit 14 proceeds to a process (S502) to confirm whether the calculated hot water outlet conditions are sufficient to meet the hot water supply request. In this confirmation process, the HP control unit 14 determines whether each hot water outlet temperature after mixing is within a range of approximately 2°C of the remote control set temperature, and if it is not within this range, changes the hot water outlet conditions. Therefore, the HP control unit 14 calculates the difference between the calculated mixed temperature and the remote control set temperature (60°C) and determines whether the difference is less than 2°C. As a result, when the outlet temperature of the HP water heater 4 is 25°C, the mixed outlet temperature is the lowest at 62.3°C, but since the difference from the remote control set temperature of 60°C is more than 2°C, it is determined that the hot water outlet condition cannot be met (S502).

[0098] HP control unit 14 determines that the hot water supply demand cannot be met because HP water heater 4 is outputting a small amount of hot water at a low temperature, while multi-water heater 6 is outputting a large amount of hot water at a high temperature, and therefore performs processing to increase the hot water output from HP water heater 4. In other words, the ratio (flow rate ratio) between hot water supply with a high temperature and a large amount of hot water and hot water supply with a low temperature and a small amount of hot water has a significant impact on the hot water output temperature when mixed. If the HP control unit 14 sets the outlet hot water temperature of the HP water heater 4 to 25°C and the hot water output rate to 4 L / min, 5 L / min, and 6 L / min, which are increased by 1 from 3 L / min, as shown in Fig. 12B, the hot water output rate on the multi-hot water heater 6 side corresponding to this hot water output rate on the HP water heater 4 side will be 41 L / min, 40 L / min, and 39 L / min, respectively.The HP control unit 14 then calculates the outlet hot water temperatures after mixing using equation (1), which are 61.4°C, 60.6°C, and 59.7°C, respectively (S503). For example, as shown in C of Figure 12, the HP control unit 14 calculates the difference between the mixed temperature calculated from the hot water output rate of the HP water heater 4 and the remote control set temperature, selects 6 [L / min] as the hot water output rate when the mixed temperature is closest to the remote control set temperature, and adjusts the hot water output rate for the HP water heater 4 (S504). In addition, when selecting the hot water output volume of the HP water heater 4, for example, multiple flow rate values ​​for the HP water heater 4 can be selected by increasing or decreasing them by 1 L / min, and the difference between the mixed temperature calculated corresponding to these flow rate values ​​and the remote control set temperature can be calculated, and the flow rate value when the positive or negative value of the difference value is reversed as the flow rate value increases or decreases can be used.

[0099] <Resetting of hot water discharge conditions> In this resetting process, as shown in FIG. 11, for example, a calculation example is shown in which the hot water discharge conditions are reset when the total hot water discharge amount decreases. When the HP control unit 14 determines that the total hot water output has decreased from 45 L / min to 15 L / min (S601) based on the detection value of the flow sensor 23, it executes a post-mixing hot water output temperature calculation process (S602) to correspond to that total hot water output, determines the hot water output conditions, and sets them as a hot water output instruction to the HP water heater 4.

[0100] When the HP control unit 14 generates the hot water supply control table 60, as shown in A of Figure 13, for example, it maintains the hot water output rate of 6 [L / min] set for the HP water heater 4, and uses this hot water output rate to calculate 9 [L / min], which is the total hot water output rate of 15 [L / min] minus 6 [L / min], as the hot water output rate of the multi-water heater 6. At this time, the HP control unit 14 may reduce the number of operating gas water heaters 24-1, 24-2, etc., depending on the hot water output rate of the multi-water heater 6, and may also perform processing such as selecting equipment to be stopped. In addition, the HP control unit 14, for example, maintains the outlet hot water temperature on the multi-water heater 6 side at 65 [°C], while selecting three outlet hot water temperatures for the HP water heater 4: 25 [°C], 35 [°C], and 45 [°C] within the limited range of 25 [°C] to 45 [°C].

[0101] Then, HP control unit 14 uses the hot water outlet conditions of selected HP water heater 4 and multi-water heater 6 to calculate the expected hot water outlet temperature after mixing based on the heat quantity calculation process as shown in equation (1). As shown in A of Fig. 13, for the three types of hot water outlet temperatures for HP water heater 4, 25 [°C], 35 [°C], and 45 [°C], the hot water outlet temperatures after mixing, from lowest to highest, are 49.0 [°C], 53.0 [°C], and 57.0 [°C], respectively.

[0102] Next, the HP control unit 14 proceeds to a process (S603) to confirm whether the calculated hot water outlet conditions are sufficient to meet the hot water supply request. In this confirmation process, the HP control unit 14 determines whether each hot water outlet temperature after mixing is within a range of approximately 2°C of the remote control set temperature, and if it is not within this range, changes the hot water outlet conditions. Therefore, the HP control unit 14 calculates the difference between the calculated mixed temperature and the remote control set temperature (60°C) and determines whether the difference is less than 2°C. As a result, when the outlet temperature of the HP water heater 4 is 45°C, the mixed outlet temperature is 57.0°C, which is the highest temperature, but since the difference from the remote control set temperature of 60°C is more than 2°C, it is determined that the hot water outlet condition cannot be met (S603). The reason why the temperature of the hot water discharged after mixing is low is that, for example, the proportion of the hot water discharged from the low-temperature HP water heater 4 is large compared to the total hot water discharge, and at the same time the proportion of the hot water discharged from the high-temperature multi-water heater 6 is small, so that insufficient heat is provided for the total hot water discharge. Therefore, in the hot water supply condition resetting process, the proportion of hot water supply from the low-temperature HP water heater 4 is reduced and the proportion of hot water supply from the high-temperature multi-water heater 6 is increased to calculate hot water supply conditions that can meet the hot water supply demand (S604).

[0103] If the HP control unit 14 selects the hot water output rate of the HP water heater 4 to 5 L / min, 4 L / min, or 3 L / min, each reduced by 1 from 6 L / min, as shown in B of Figure 13, the hot water output rate on the multi-water heater 6 side corresponding to the hot water output rate on the HP water heater 4 side will be 10 L / min, 11 L / min, or 12 L / min, respectively. Then, the HP control unit 14 calculates the outlet hot water temperatures after mixing using formula (1), and the results are 58.3°C, 59.7°C, and 61.0°C, respectively (S604).

[0104] For example, as shown in C of Figure 13, the HP control unit 14 takes the difference between the mixed temperature calculated from the hot water outlet temperature (45°C) of the HP hot water heater 4 and the hot water outlet volume value and the remote control set temperature, selects 3 [L / min], which is the hot water outlet volume when the positive and negative signs of the difference between the mixed temperature and the remote control set temperature are reversed, and adjusts the hot water outlet volume of the HP hot water heater 4 (S605).

[0105] In this embodiment, an example of the process for resetting the hot water discharge conditions when the total hot water discharge amount decreases significantly during hot water supply processing using the second hybrid hot water discharge mode is shown, but such a calculation method can also be performed in the same way when the total hot water discharge amount increases. Additionally, although this embodiment describes the processing in the hot water supply system 2 that uses the HP hot water heater 4 as the first hot water supply means, the technology of the present disclosure is not limited to this content. In the hot water supply system 70 that uses the solar tank unit 72, the control unit 82 can similarly perform the processing to set the hot water outlet temperature and hot water output amount on the solar tank unit 72 side and the hot water outlet temperature on the multi-hot water heater 6 side when executing the second hybrid hot water outlet mode. [Modification]

[0106] The features and modifications of the above-described embodiments and examples are listed below.

[0107] (1) In the above embodiment and example, as an example of a process to be performed when the total hot water output volume fluctuates during hot water supply in hybrid hot water supply mode, a process to reset the hot water output conditions is described as being performed when a fluctuation in the hot water output volume is detected. However, this is not limited to this. For example, if the detected value of the flow sensor 23 fluctuates, the HP control unit 14 and the control unit 82 may wait for a predetermined time and monitor the fluctuation in the flow rate during that time. After the predetermined time has elapsed, the HP control unit 14 and the control unit 82 may reset the hot water output conditions based on a stable detected flow rate value, the average value of the flow rate values ​​detected during the predetermined time, or upper and lower limit values ​​as the fluctuation value of the total hot water output volume. Furthermore, if the detected flow rate value repeatedly fluctuates significantly over a short period of time, the set hot water output conditions may be maintained, or an error warning may be issued using a notification means (not shown) provided in the HP control unit 14, the control unit 82, the hot water supply control units 26-1 and 26-2, or the remote control 8. This prevents unnecessary calculation processes in response to temporary fluctuations in flow rate, as well as preventing the reset process from being repeated in a short period of time, thereby reducing the load on the HP control unit 14, control unit 82, HP water heater 4, solar tank unit 72, and multi-water heater 6. It also prevents the hot water temperature from fluctuating frequently for users of the hot water supply system 2.

[0108] (2) In the above-described embodiment and example, the hot water supply system 2, 70 includes an HP water heater 4 or a solar tank unit 72 having one tank unit 12 and a multi-water heater 6 having two gas water heaters 24-1, 24-2. However, this is not limited to this. In the hot water supply system 2 of the present disclosure, for example, one HP water heater 4 or solar tank unit 72 may include two or more tank units 12, or multiple HP water heaters 4 or solar tank units 72 having one or more tank units 12 may be linked together. Furthermore, the hot water supply system 2 may include 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. Furthermore, the HP water heater 4 and the solar tank unit 72 may be used together as the first hot water supply means.

[0109] (3) In the second embodiment, the solar collector 74 and the tank unit 12 are connected by the heat collection circuit 76, and the heat medium HM flows into the heat exchanger 80 by operating the circulation pump 78. However, this configuration is not limited to this. The heat collection circuit 76 may be provided with a bypass passage that bypasses the heat exchanger 80 and allows the heat medium HM to flow from the return pipe to the supply pipe. This bypass passage may be provided with a bypass valve that limits or blocks the flow of the heat medium HM into the heat exchanger 80. This prevents the hot water supply system 70 from flowing low-temperature heat medium HM into the tank unit 12 when solar heat is not being collected. This can also be used to limit heat exchange between the hot water in the tank unit 12 and the heat medium HM when the hot water supply mode is switched to the second hybrid hot water supply mode. In other words, the bypass passage and the bypass valve can be used to control the temperature of the hot water stored in the tank unit 12 by adjusting the frequency of heat exchange between the heat medium HM and the hot water.

[0110] (4) In the second embodiment described above, the control unit 82 performs heat collection processing by combining information such as the hot water temperature in the tank unit 12 with information on the season, weather, and hours of sunshine, and may also use these as information for determining whether or not to switch to hybrid hot water discharge mode.

[0111] As explained 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. Various modifications and changes are possible for those skilled in the art based on the gist of the invention as described in the claims or disclosed in the description for carrying out the invention. It goes without saying that such modifications and changes are included in the technical scope of the present disclosure. [Industrial Applicability]

[0112] The hot water supply method, system, and program disclosed herein are useful in a hot water supply system that combines a first hot water supply means including a tank unit for storing heated hot water and a second hot water supply means equipped with one or more gas hot water heaters.By setting a hot water supply mode that changes the hot water supply conditions on the first hot water supply means side depending on the heat storage state in the tank unit and supplying hot water together with the second hot water supply means, the efficiency of utilizing the heat stored in the tank unit can be increased. [Explanation of symbols]

[0113] 2.70 Hot water system 4 HP water heater 6 Multi-water heater 8 Remote Control Device 10 HP unit 12 Hot water storage tank unit 14 HP control unit 16 Circulation path 18 Water supply circuit 20 Hot water circuit 22, 27, 46-1, 46-2, 48-1, 48-2, 50-1, 50-2, 84, 86 Temperature sensors 23, 25, 52-1, 52-2 Flow sensors 24-1, 24-2 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 Control Table 61 HP Water Heater Information Department 62 Multi-water heater information department 63 Mixed water outlet capacity section 64 Flow rate information section 65 Hot water temperature information section 72 Solar Tank Unit 74 Solar collector 76 Solar heat collection circuit 78 Circulation Pump 80 Heat exchange section 82 Control Unit

Claims

1. A hot water supply method for a hot water supply system capable of using a first hot water supply means that supplies hot water using hot water heated by a first heat source and stored in a hot water storage tank, and a second hot water supply means that supplies hot water using hot water heated by a second heat source, a step of monitoring the total amount of hot water discharged based on the detection result of a flow rate detection means while supplying hot water in a hybrid hot water discharge mode in which the control unit of the first hot water supply means operates under hot water discharge conditions in which the hot water discharge temperature and amount of hot water discharged from the first hot water supply means are reduced in response to the heat storage temperature in the hot water storage tank becoming lower than the set temperature of the hot water supply request, and the hot water discharge temperature of the second hot water supply means is made higher than the set temperature of the hot water supply request; When the control unit confirms a change in the total amount of hot water discharged, it generates a hot water discharge instruction for correcting at least one of the amount of hot water discharged from the first hot water supply means, or a combination thereof, based on the changed total amount of hot water discharged and the set temperature of the hot water supply request, for the hot water discharge conditions of the hybrid hot water discharge mode; A hot water supply method including:

2. a step in which, when the control unit determines that the total hot water output volume has changed, it maintains the hot water output volume of the first hot water supply means and the hot water output temperature of the second hot water supply means among the hot water output conditions, calculates the hot water output volume of the second hot water supply means from the total hot water output volume after the change, modifies the hot water output conditions including the hot water output temperature of the first hot water supply means within a predetermined temperature limit range, and determines whether hot water can be output at the same value as the set temperature of the hot water supply request or within a certain range including said same value based on the heat quantity calculated from the hot water output volume and hot water output temperature of the first hot water supply means and the second hot water supply means; a step of adjusting the hot water discharge amount of the first hot water supply means when the control unit determines that hot water cannot be discharged at the set temperature of the hot water supply request under the modified hot water discharge conditions, and adjusting the hot water discharge conditions based on the adjusted hot water discharge amount and the heat quantity of the hot water supplied from the first hot water supply means and the second hot water supply means; The hot water supply method according to claim 1, comprising:

3. The control unit sets the hot water discharge conditions by gradually changing the amount of hot water discharged from the first hot water supply means by a predetermined value, and compares the difference between the hot water discharge temperature after mixing, calculated based on the calorific value of the hot water discharged from the first hot water supply means and the set temperature of the hot water supply request; the control unit adjusts the hot water outlet amount of the first hot water supply means among the hot water outlet conditions by the comparison so that the sign of the difference between the outlet temperature of the hot water after mixing and the set temperature is reversed; The hot water supply method according to claim 2, comprising:

4. A hot water supply system capable of using a first hot water supply means that supplies hot water using hot water heated by a first heat source and stored in a hot water storage tank, and a second hot water supply means that supplies hot water using hot water heated by a second heat source, a flow rate detection means for detecting a total hot water supply amount requested; a control means for monitoring changes in the total hot water output amount of the hot water supply request based on the detection results of the flow rate detection means during hot water supply in a hybrid hot water supply mode in which the first hot water supply means is operated under hot water supply conditions in which the hot water output temperature and hot water output amount are reduced in response to the heat storage temperature in the hot water storage tank becoming lower than the set temperature of the hot water supply request, and the second hot water supply means is operated under hot water supply conditions in which the hot water output temperature is higher than the set temperature of the hot water supply request, and when a change in the total hot water output amount is confirmed, generating a hot water output instruction to modify at least the hot water output amount or hot water output temperature from the first hot water supply means, or a combination thereof, for the hot water supply conditions of the hybrid hot water supply mode based on the changed total hot water output amount and the set temperature of the hot water supply request; A hot water system comprising:

5. The control means, in response to a change in the total hot water output volume, maintains the hot water output volume of the first hot water supply means and the hot water output temperature of the second hot water supply means among the hot water output conditions, calculates the hot water output volume of the second hot water supply means from the changed total hot water output volume, and modifies the hot water output conditions including the hot water output temperature of the first hot water supply means within a predetermined temperature limit range, and determines whether hot water can be output at the same value as the set temperature of the hot water supply request or within a certain range including that same value based on the heat quantity calculated from the hot water output volumes and hot water output temperatures of the first hot water supply means and the second hot water supply means, A hot water supply system as described in claim 4, wherein if it is determined that the modified hot water supply conditions do not allow hot water to be supplied at the set temperature of the hot water supply request, the hot water supply amount of the first hot water supply means is adjusted, and the hot water supply conditions are adjusted based on this adjusted hot water supply amount and the heat quantity of the hot water supplied from the first hot water supply means and the second hot water supply means.

6. The hot water supply system of claim 5, wherein the control means sets the hot water discharge conditions in which the hot water discharge amount of the first hot water supply means is changed in stages by a predetermined value, compares the difference between the discharge temperature of the mixed hot water calculated based on the heat quantity of the hot water discharged from the first hot water supply means and the set temperature of the hot water supply request, and adjusts the hot water discharge amount of the first hot water supply means among the hot water discharge conditions based on this comparison so that the positive and negative values ​​of the difference between the discharge temperature of the mixed hot water and the set temperature are reversed.

7. The hot water supply system of claim 4, characterized in that the first heat source of the first hot water supply means uses air heat using a heat pump or solar heat using a solar collector, and the second heat source of the second hot water supply means uses heat generated by burning fuel gas.

8. A computer program for a hot water supply system capable of using a first hot water supply means that supplies hot water using hot water heated by a first heat source and stored in a hot water storage tank, and a second hot water supply means that supplies hot water using hot water heated by a second heat source, a function of monitoring the total amount of hot water discharged based on the detection result of the flow rate detection means during hot water supply in a hybrid hot water supply mode in which the hot water supply temperature and amount of hot water discharged from the first hot water supply means are reduced in response to the heat storage temperature in the hot water storage tank becoming lower than the set temperature of the hot water supply request, and the hot water supply temperature of the second hot water supply means is set to a temperature higher than the set temperature of the hot water supply request; When a change in the total amount of hot water discharged is confirmed, a function of generating a hot water discharge instruction for correcting at least one of the amount of hot water discharged from the first hot water supply means, the hot water discharge temperature, or a combination thereof, based on the changed total amount of hot water discharged and the set temperature of the hot water supply request, for the hot water discharge conditions of the hybrid hot water discharge mode; A program for causing the computer to execute the above.

9. a function of, in response to a change in the total hot water output amount, maintaining the hot water output amount of the first hot water supply means and the hot water output temperature of the second hot water supply means among the hot water output conditions, calculating the hot water output amount of the second hot water supply means from the total hot water output amount after the change, and correcting the hot water output conditions including the hot water output temperature of the first hot water supply means within a predetermined temperature limit range; a function of determining whether hot water can be dispensed at the same temperature as the set temperature of the hot water supply request or within a certain range including the same temperature, based on the heat quantity calculated from the hot water dispensed amount and the hot water dispensed temperature of the first hot water supply means and the second hot water supply means; a function of adjusting the hot water discharge amount of the first hot water supply means when it is determined that hot water cannot be dispensed at the set temperature of the hot water supply request under the modified hot water discharge conditions, and modifying the hot water discharge conditions based on the adjusted hot water discharge amount and the heat quantity of the hot water supplied from the first hot water supply means and the second hot water supply means; The program according to claim 8, which causes the computer to execute the following.

10. a function of setting the hot water discharge conditions by changing the amount of hot water discharged from the first hot water supply means in stages by a predetermined value, and comparing the difference between the hot water discharge temperature after mixing, calculated based on the calorific value of the hot water discharged from the first hot water supply means and the set temperature of the hot water supply request; a function of adjusting the hot water discharge amount of the first hot water supply means among the hot water discharge conditions by this comparison so that the positive and negative values ​​of the difference between the hot water discharge temperature after mixing and the set temperature are reversed; The program according to claim 9, which causes the computer to execute the following.

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