JP2020197332A - Hot water supply method, hot water storage unit, hot water supply system and program - Google Patents

Abstract

To prevent fluctuation of a hot water supply temperature caused by start responsiveness of a heat source device to continue stable hot water supply, even when heat storage in a hot water storage tank runs short.SOLUTION: A hot water supply method includes processes of: acquiring heat accumulation state information (temperature sensor) of hot water in a hot water storage tank; causing hot water whose temperature is adjusted to a first set temperature (Temp1) to flow to auxiliary heating means (water heater) side in a mixing section (mixing water control valve) mixing water with hot water delivered from the hot water storage tank; and changing a set temperature in the mixing section to a second set temperature (Temp2) lower than the first set temperature (Temp1) when the heat accumulation state in the hot water storage tank reaches a state that enables hot water supply in accordance with a hot water supply request and that is less than a threshold value (P).SELECTED DRAWING: Figure 1

Description

The present invention relates to a hybrid hot water supply technique that uses, for example, a hot water storage unit as a heat storage source, a heat pump as a heat supply source, and a water heater as a hot water supply heating means.

A hybrid hot water supply system has been put into practical use that stores hot water by storing hot water heated by the heat of an external heat source such as a heat pump, discharges the stored hot water in response to a hot water supply request, and heats it with a water heater according to the heat storage state. There is.

Regarding a hot water supply system that supplies hot water by using such stored hot water and heats it with a heating device, a mixing unit that mixes a predetermined amount of tap water with hot water discharged from the hot water storage tank to lower the temperature. There is a mixing unit that mixes water with hot water to adjust the temperature and then flows it to the hot water outlet side. (For example, Patent Document 1 and Patent Document 2).

Japanese Unexamined Patent Publication No. 2005-42965 Japanese Unexamined Patent Publication No. 2007-315749

By the way, in a hot water supply system that supplies hot water using hot water stored in a hot water storage tank, the heat storage in the hot water storage tank is consumed as the demand for hot water supply increases. In the hot water supply system, when the heat in the hot water storage tank is consumed and the hot water that meets the hot water supply request cannot be supplied, the hot water is supplied by heating with a water heater that is an auxiliary heat source. When the heat storage in the hot water storage tank is insufficient during hot water supply and auxiliary heating by the water heater is started, the heating rate by the combustion part cannot keep up with the time from the ignition of the burner to the stabilization of the heating state and the temperature decrease rate of the hot water. There is a problem that the hot water supply temperature may drop temporarily.

In addition, when introducing a hybrid hot water supply system by installing a hot water storage tank unit in the hot water supply facility or replacing some of the existing hybrid hot water supply system equipment, the water heater and the hot water storage tank unit may be different manufacturers' equipment. is there. In this way, it is difficult to link and integrate the control contents because the operating specifications are different for different manufacturers, and it is impossible to perform integrated control and management with a common remote controller with control methods having different communication rules. Therefore, in order to control the combustion start timing of the hot water supply device based on the monitoring result of the heat storage state in the hot water storage tank, a new control device that controls the entire hybrid hot water supply system is added, and the remote control device of each device is used. There is a problem that it is difficult to introduce the system, such as increasing the cost of the device and increasing the workload, such as standardizing the control algorithm.
Such a problem is not disclosed or suggested in Patent Document 1 and Patent Document 2, and such a problem cannot be solved by the configuration disclosed in Patent Document 1 and Patent Document 2.

Therefore, an object of the present invention is to prevent fluctuations in the hot water supply temperature due to the start response of the heat source device even if a shortage of heat storage in the hot water storage tank occurs, and to continue stable hot water supply.

In order to achieve the above object, one aspect of the hot water supply method of the present invention is a step of acquiring heat storage state information of hot water in the hot water storage tank and a mixing unit for mixing water with hot water discharged from the hot water storage tank. When the step of flowing the hot water adjusted to the set temperature of the above to the auxiliary heating means side and the heat storage state of the hot water storage tank can supply hot water according to the hot water supply request and become less than the threshold value, the set temperature of the mixing unit is reached. Includes a step of changing the temperature to a second set temperature lower than the first set temperature.

In this hot water supply method, a step of adjusting the hot water from the mixing portion within the range of the ignition start temperature of the auxiliary heating means by the second set temperature may be included.
In this hot water supply method, further, a step of detecting the temperature of the hot water discharged from the hot water storage tank, and at least the first set temperature or the second set temperature, the water supply temperature, and the hot water discharged from the hot water storage tank It may include a step of calculating the mixing ratio of water according to the temperature and a step of controlling the amount of water supplied and the amount of hot water discharged from the hot water storage tank based on the calculated mixing ratio.
In this hot water supply method, further, a step of detecting a mixed hot water temperature of a mixture of hot water and water discharged from the hot water storage tank, and an ignition start of the auxiliary heating means when the mixed hot water temperature is higher than the hot water supply required temperature. It may include a step of determining whether or not it is within the temperature range.
In this hot water supply method, the range of the ignition start temperature may be such that the temperature of the water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature.

In order to achieve the above object, one aspect of the hot water storage unit of the present invention includes a hot water storage tank for storing heated hot water, a heat storage state information acquisition means for acquiring heat storage state information of hot water in the hot water storage tank, and the hot water storage tank. The heat storage state of the hot water storage tank and the mixing unit that mixes water with the hot water discharged from the hot water and flows the hot water adjusted to the first set temperature to the auxiliary heating means side can be supplied according to the hot water supply request and is less than the threshold value. A control unit for changing the set temperature of the mixing unit to a second set temperature lower than the first set temperature is provided.

In this hot water storage unit, the second set temperature is within the range of the ignition start temperature of the auxiliary heating means, and the control unit may adjust the temperature of the hot water to the second set temperature and allow it to flow. ..
In this hot water storage unit, the range of the ignition start temperature may be such that the temperature of water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature.
The hot water storage unit further includes a tank hot water temperature sensor that detects the temperature of hot water discharged from the hot water storage tank, and the control unit has at least the first set temperature or the second set temperature, the water supply temperature, and the above. The mixing ratio of water may be calculated from the temperature of the hot water discharged from the hot water storage tank to control the amount of water supplied and the amount of hot water discharged from the hot water storage tank.

In order to achieve the above object, one aspect of the hot water supply system of the present invention is a hot water storage tank for storing heated hot water, a heat storage state information acquisition means for acquiring heat storage state information of hot water in the hot water storage tank, and the hot water storage tank. The heat storage state of the hot water storage tank and the mixing unit that mixes water with the hot water discharged from the hot water and flows the hot water adjusted to the first set temperature to the auxiliary heating means side can be supplied according to the hot water supply request and is less than the threshold value. A control unit for changing the set temperature of the mixing unit to a second set temperature lower than the first set temperature is provided.

In this hot water supply system, the mixing unit may adjust the temperature of the hot water within the range of the ignition start temperature of the auxiliary heating means by changing to the second set temperature.
In this hot water supply system, the range of the ignition start temperature may be such that the temperature of the water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature.
In this hot water supply system, a tank hot water temperature sensor for detecting the temperature of hot water discharged from the hot water storage tank is further provided, and the control unit is at least at least the first set temperature or the second set temperature, the water supply temperature and the like. The mixing ratio of water may be calculated from the temperature of the hot water discharged from the hot water storage tank to control the amount of water supplied and the amount of hot water discharged from the hot water storage tank.

In order to achieve the above object, one aspect of the program of the present invention is a hot water supply program realized by a computer, which has a function of acquiring heat storage state information of hot water in a hot water storage tank and water in hot water discharged from the hot water storage tank. In the mixing section where the hot water is mixed, the function of adjusting the hot water to the first set temperature and flowing it to the auxiliary heating means side, and the state where the heat storage state of the hot water storage tank can supply hot water according to the hot water supply request and is less than the threshold value. It includes a function of changing the set temperature of the mixing unit to a second set temperature lower than the first set temperature.

In this hot water supply program, the mixing unit may include a function of adjusting the temperature of the hot water within the range of the ignition start temperature of the auxiliary heating means by changing the temperature to the second set temperature.
In this hot water supply program, the range of the ignition start temperature may be such that the temperature of the water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature.
In this hot water supply program, the function of acquiring the detection temperature information of the hot water discharged from the hot water storage tank, and at least the first set temperature or the second set temperature, the water supply temperature, and the high temperature discharged from the hot water storage tank The computer may be made to execute a function of calculating the mixing ratio of water based on the temperature of hot water and a function of controlling the amount of water supplied and the amount of hot water discharged from the hot water storage tank based on the calculated mixing ratio.

According to the present invention, any of the following effects can be obtained.
(1) By starting the hot water supply device, which is an auxiliary heat source, before the heat storage in the hot water storage tank becomes insufficient, temperature fluctuations during hot water discharge can be suppressed.
(2) Even if the water heater, which is an auxiliary heat source, is started due to insufficient heat storage in the hot water storage tank while using hot water supply, the hot water supply temperature does not drop, so the user who is using hot water supply does not feel unpleasant and the device is connected. The reliability can be increased.
(3) By changing the set temperature to adjust by mixing hot water discharged from the hot water storage tank and low temperature water, it is possible to adjust the timing of auxiliary heating without controlling the operation of the hot water supply device.
(4) By setting the temperature of the hot water discharged from the mixing part of the hot water storage tank unit to a value higher than the required hot water supply temperature and within the ignition start temperature range of the water heater, the heating capacity when the water heater is started Hot water can be supplied according to the required temperature by reducing the influence of fluctuations.

It is a flowchart which shows an example of the hot water supply control which concerns on 1st Embodiment. It is a figure which shows the structural example of the hot water supply system which concerns on 2nd Embodiment. It is a figure which shows the structural example of a water heater. It is a figure which shows the structural example of the control part of a hot water storage unit. It is a figure which shows the structural example of the control part of a water heater. It is a graph which shows the state example of the temperature change of hot water by a hot water supply system. It is a flowchart which shows an example of hot water supply control. It is a flowchart which shows an example of the operation control of a water heater. It is a figure which shows the structural example of the hot water supply system which concerns on 3rd Embodiment. It is a graph which shows the comparative example of a hot water supply process.

[First Embodiment]
FIG. 1 shows an example of hot water supply control according to the first embodiment. The processing content and processing procedure shown in FIG. 1 are examples, and the present invention is not limited to such content. This hot water supply control process is an example of the hot water supply method or program of the present invention.

In this hot water supply process, hot water is stored in the hot water storage unit 4 (S101), heat storage state information in the hot water storage tank 10 is acquired (S102), hot water in the hot water storage tank is discharged (S103), and hot water and water discharged from the hot water storage tank 10 are mixed. It includes a process of mixing by the mixed water control valve 12 which is a unit and adjusting to a set temperature (S104), a determination of a heat storage state (S105), and a change of a set temperature in the mixing unit (S106).
Hot water storage (S101) of the hot water storage unit 4: Hot water is stored in the hot water storage tank 10 of the hot water storage unit 4 using the heat pump 6 as a heat source. The heat pump 6, which is an example of the heat source unit, is usually maintained in a driven state, and the hot water HW heated by the heat pump 6 is stored in the hot water storage tank 10.

Acquisition of heat storage state information in the hot water storage tank 10 (S102): The temperature of hot water at a predetermined height in the hot water storage tank 10 is measured in order to determine whether or not hot water can be discharged at a temperature corresponding to the hot water supply request. The hot water storage tank 10 stores high-temperature hot water in the upper part, and performs hierarchical heat storage in which the temperature decreases toward the lower part. Therefore, by measuring the temperature of hot water at a predetermined height, it is possible to grasp the temperature distribution in the tank and the heat storage state such as the hot water supply capacity. In the determination of the heat storage state, for example, the temperature at one location in the hot water storage tank 10 may be detected, and the temperature at a plurality of locations having different heights may be detected. By increasing the position of temperature detection, a more detailed heat storage state can be grasped.
Hot water in the hot water storage tank is discharged (S103): When the water supply W flows through the water supply pipe 14 by the opening operation of the faucet 32, a part of the water supply W flows into the bottom side of the hot water storage tank 10 and the hot water is stored according to the inflow amount. The hot water HW on the upper layer side of the tank 10 flows into the hot water supply line 18. The hot water supply demand may be detected by, for example, a water flow sensor 40 installed in the water supply pipe 14.
Process of mixing hot water and water discharged from the hot water storage tank 10 with the mixed water control valve 12 and adjusting the temperature to the set temperature (S104): The hot water HW discharged from the hot water storage tank 10 is sent to the mixed water control valve 12 according to the hot water supply demand. Then, it is mixed with the water supply W to generate hot water at a set temperature. At this time, a first set temperature is set in the mixed water control valve 12 as a control process for supplying hot water without operating the water heater 8 which is an auxiliary heat source. The hot water HW that has passed through the mixed water control valve 12 passes through the water heater 8 from the hot water supply pipe 26 and flows to the hot water supply load through the hot water outlet pipes 28 and 30. In this hot water supply process, for example, the temperature of the water supply is detected by the temperature sensor 16-1, and the temperature of the hot water discharged from the hot water storage tank 10 is detected by the temperature sensor 16-2, and these temperature information and the mixed water control valve 12 are set. The mixing ratio of water in the mixed water control valve 12 is calculated based on the set temperature. Then, the amount of hot water discharged from the hot water storage tank 10 is adjusted by setting the opening degree of the mixed water control valve 12 based on the calculated mixing ratio.
Judgment of heat storage state (S105): When the hot water supply request continues, the heat storage state information in the hot water storage tank 10 is continuously collected, and whether or not the heat storage state in the hot water storage tank 10 is less than a preset threshold value is determined. Judgment The threshold used for this judgment may be determined by whether or not there is a hot water HW having a temperature at which hot water can be supplied according to the hot water supply request through the hot water supply system 2.
Change of hot water set temperature (S106): In the hot water storage unit 4, in order to start the auxiliary heat source before the amount of heat in the hot water storage tank 10 cannot meet the hot water supply demand, the mixed water control valve 12 on the hot water discharge side of the hot water storage unit 4 is used. The temperature of the hot water to be generated is changed to the second set temperature. The changed second set temperature is, for example, a temperature higher than the temperature of the hot water HW finally discharged from the hot water supply system 2 and a temperature in a range in which the water heater 8 ignites and starts the heat treatment.

<Effect of the first embodiment>
According to this first embodiment, any of the following effects can be obtained.
(1) By changing the set temperature of the hot water generated by the mixed water control valve 12 according to the heat storage state in the hot water storage tank 10 and starting the water heater, the heat treatment by the water heater 8 becomes unstable. Even if there is, the temperature of the hot water finally discharged from the curan 32 does not fluctuate.
(2) In the process of determining the heat storage state in the hot water storage tank, the water heater 8 is started without causing the hot water to run out by setting the heat storage state in which hot water can be discharged using the hot water HW in the hot water storage tank 10 as a threshold value. It is possible to prevent the temperature of the hot water from dropping and destabilization due to running out of hot water.
(3) By starting the auxiliary heating before the hot water in the hot water storage tank 10 runs out, the user does not feel uncomfortable due to the decrease in the hot water temperature.
(4) The start control of the water heater 8 which is an auxiliary heat source can be performed only by changing the set temperature at which hot water is discharged through the mixed water control valve 12 of the hot water storage unit 4, and the convenience is enhanced.

[Second Embodiment]
FIG. 2 shows a hot water supply system according to the second embodiment. The configuration shown in FIG. 2 is an example, and the present invention is not limited to such a configuration.

<About hot water supply system 2>
The hot water supply system 2 includes a hot water storage unit 4, a heat pump 6, and a water heater 8. The water heater 8 may be operated by, for example, one unit, or a plurality of water heaters 8 may be operated simultaneously or in accordance with a predetermined instruction control.
A water supply pipe 14 is connected to the bottom of the hot water storage tank 10, and water supply W such as tap water is supplied to the lower layer side of the hot water storage tank 10. On the water supply pipe 14, a temperature sensor 16-1 for detecting the inflow temperature (Tin) of the water supply W and a water flow sensor 40 for detecting the flow rate of the water supply W are installed.
In addition, the hot water supply system 2 is, for example, a water supply that branches from a hot water outlet pipe 28 for flowing hot water that has passed through the water heater 8, a hot water outlet pipe 30 for flowing to the curan 32 side, and a water supply pipe 14 to supply low temperature water supply W to the curan 32. It has a supply pipe 34. In this hot water supply system 2, hot water is supplied to the hot water outlet pipe 30 through the hot water storage unit 4 and the water heater 8, and is mixed with the low temperature water supply W in the faucet 32 to generate hot water according to the hot water supply request, so-called thermo. A mixing method is adopted.

<About hot water storage unit 4>
A hot water supply pipe 18 for flowing high-temperature hot water HW in the hot water storage tank 10 is connected to the upper side of the hot water storage tank 10. A temperature sensor 16-2 for detecting the hot water outlet temperature (Ttnk) is provided on the hot water supply pipe line 18.
Inside the hot water storage tank 10, a temperature sensor 16-3 for detecting the temperature (Tsto) of hot water installed at a predetermined height is provided. The temperature sensor 16-3 is an example of a heat storage state information acquisition means for monitoring the heat storage state in the hot water storage tank based on the temperature of the hot water in the tank and the height at which the hot water is installed. In the hot water storage tank 10 which is a hierarchical heat storage, the temperature of the hot water HW above the installation or temperature measurement position of the temperature sensor 16-3 is high. That is, when the temperature detected by the temperature sensor 16-3 satisfies the setting condition for hot water supply, at least the volume above the installation position of the temperature sensor 16-3 is the amount of heat storage that can be supplied. Therefore, when the detected temperature of the temperature sensor 16-3 does not satisfy the set temperature condition for hot water supply, it indicates that there is a high possibility that the heat storage available for hot water supply at the set temperature will be insufficient.
The temperature information detected by each sensor is provided to the control unit 49 that controls the hot water storage unit 4.

The mixed water control valve 12 is an example of the mixing unit of the present invention, and is installed between the water supply pipe 14 and the hot water supply pipe line 18. The mixed water control valve 12 is a distribution valve 22 that branches a part of the low-temperature water supply W flowing in the water supply pipe 14, and a bypass pipe 20 that bypasses the hot water storage tank 10 and allows the distributed water supply W to flow to the hot water supply pipe line 18 side. It has a water control valve 24 that merges the distributed water supply W with the hot water HW in the hot water supply pipe 18 and controls the flow rate of the merged hot water HW. The mixing ratio of the hot water HW and the water supply W is determined by the opening degree of the distribution valve 22. In the hot water supply control, for example, the amount of water supplied by the water supply W flowing through the water supply pipe 14 is detected by the water flow sensor 40, and based on the hot water discharge temperature of the hot water HW in the hot water storage tank 10 and the set temperature set in the mixed water control valve 12. The opening degree of the distribution valve 22 may be calculated.
A hot water supply pipe line 26 is connected to, for example, the mixed water control valve 12 in the hot water storage unit 4, and hot water HW adjusted to a set temperature by the mixed water control valve 12 flows to the water heater 8 side. A temperature sensor 16-4 for detecting the hot water discharge temperature (Tmix-tu) from the hot water storage unit 4 is installed in the hot water supply pipe line 26. Then, the control unit 49 adjusts the opening degree of the mixed water control valve 12 so that the hot water discharge temperature detected by the temperature sensor 16-4 becomes the set temperature.

The heat pump 6 is an example of a heat source that heats the hot water HW of the hot water storage tank 10 by, for example, electric heat. Between the hot water storage tank 10 and the heat pump 6, a heat giving circulation path for circulating hot water HW between the hot water storage tank 10 and the heat pump 6 is provided. In this heat-giving forward pipe, the low-temperature hot water or the water supply W stored in the lower side of the hot water storage tank 10 flows to the heat pump 6 side, and the high-temperature hot water from the heat pump 6 to the upper side of the hot water storage tank 10. The heat giving return pipe 44 through which HW flows is included. Further, the heat applying pipe 42 and the heat returning pipe 44 have a bypass pipe 46 that bypasses the heat pump 6.
On the heat-applying pipe 42, for example, a circulation pump 48 for pumping hot water into the heat-giving circulation path and a temperature sensor 16-5 for detecting the temperature of the hot water before heating by the heat pump 6 are provided.
On the heat applying return pipe 44, for example, a temperature sensor 16-6 for detecting the temperature of hot water after heating by the heat pump 6 is provided, and a switching valve 47 is provided. The switching valve 47 switches the flow of the hot water HW from the bypass pipe 46 to the heat supply return pipe 44 when the low temperature hot water or the water supply W stored in the lower side of the hot water storage tank 10 reaches the upper limit temperature.
The heat pump 6 has, for example, a circuit in which a heat medium circulates inside, and the circuit includes a heat exchanger in which the hot water flowing in the heat giving circulation path exchanges heat with the heat medium, or a heat exchanger in which the outside air and the heat medium exchange heat. It is equipped with a compressor, expansion valve, etc., and the circulating heat medium heats up due to compression and expansion, and this heat is used to heat hot water. The heat pump 6 is constantly maintained in an operating state, and is operated independently to supplement the amount of hot water heat in the hot water storage tank 10 in preparation for hot water supply demand. When the temperature of the lower layer water of the hot water storage tank 10 reaches the upper limit temperature, the operation of the heat pump 6 may be stopped based on the detected temperature of the hot water flowing in the heating forward pipeline.

In addition, the hot water storage unit 4 has a hot water storage tank remote controller 36. The hot water storage tank remote controller 36 is an example of means for setting conditions for the set temperature of hot water discharged through the mixed water control valve 12 of the hot water storage unit 4, heat storage state information in the hot water storage unit 4, and other information.

The control unit 49 provides information on the detected temperatures of the temperature sensors 16-1, 16-2, 16-3, 16-4, 16-5, 16-6 installed in the hot water storage unit 4 and the detected flow rate of the water flow sensor 40. And control the hot water supply in response to the hot water supply request. This hot water supply control includes, for example, opening degree control of the distribution valve 22 and the water regulation valve 24. Further, as the hot water supply control of the present invention, the control unit 49 determines the heat storage state information by the temperature sensor 16-3 in the hot water storage tank 10, and when the heat storage state in the hot water storage tank 10 becomes less than the threshold value, the mixture is mixed. A process of lowering the set temperature of the hot water HW generated by the water control valve 12 is performed. As the threshold value of this heat storage state, for example, a temperature condition is set within a range having a calorific value capable of discharging hot water at a temperature corresponding to a hot water supply request without auxiliary heating by the water heater 8.

<About water heater 8>
FIG. 3 shows a configuration example of a water heater.
When the hot water HW discharged from the hot water storage unit 4 flows in through the hot water supply pipe 26, the water heater 8 assists and discharges the hot water when the temperature of the hot water does not meet the set temperature, and meets the set temperature. It passes through and flows to the hot water supply line 28 side.
The water heater 8 includes a heat exchanger 50, a burner 52, and a mixing control valve 54.
The heat exchanger 50 is an example of means for exchanging heat between the heat generated by the burner 52, which is a heat source, and the hot water HW. The burner 52, for example, burns fuel gas to generate hot combustion exhaust, and also includes an electric heater and other heat generating means.
The mixing control valve 54 has a distribution valve 64, a bypass pipe 66, and a water control valve 68, and part or all of the hot water HW supplied from the water supply pipe 60 connected to the hot water supply pipe line 26 is on the bypass pipe 66 side. And flow to the hot water pipe line 28 side.
On the water supply pipe 60, a temperature sensor 16-7, a flow rate sensor 62 for detecting the water supply flow rate, a temperature sensor 16-8 for detecting the temperature of hot water after heat exchange, and a temperature of hot water discharged from the water supply device 8 are detected. It has a temperature sensor 16-9.
Further, the water heater 8 includes a control unit 70 that controls hot water supply and a water heater remote controller 38.
The control unit 70 acquires, for example, the temperature information detected by the temperature sensors 16-7, 16-8, 16-9 and the detected flow rate information of the flow rate sensor 62, and based on these detection information, the combustion control of the burner 52 and the like. The opening degree control of the distribution valve 64 and the water regulation valve 68 is executed.

<Control unit 49 of hot water storage unit 4>
FIG. 4 shows a configuration example of the control unit of the hot water storage unit 4.
The control unit 49 is composed of a computer having a communication function, and includes, for example, a processor 72, a memory unit 74, a system communication unit 76, and an input / output unit (I / O) 78.
The processor 72 executes arithmetic processing of the OS (Operating System) and the hot water supply control program stored in the memory unit 74. The memory unit 74 stores data necessary for hot water supply control in addition to the OS and control program, and also has temperature sensors 16-1, 16-2, which are installed in the hot water storage tank 10, the water supply pipe 14, and the hot water supply pipes 18 and 26. Stores the detected temperature information of 16-3 and 16-4. The memory unit 74 includes a ROM (Read-Only Memory) and a RAM (Random-Access Memory). A storage element such as a hard disk device or a non-volatile memory for storing data is used in the memory unit 74. RAM constitutes an information processing work area.

The system communication unit 76 is wirelessly or wiredly connected to the hot water storage tank remote controller 36, and in addition to transmitting and receiving instruction information of the set temperature of the mixed water control valve 12 and operation instruction information of the hot water storage unit 4, the hot water storage unit 76 is connected. Send and receive the operation status information of 4.
The I / O 78 acquires the detection information from the water flow sensor 40 and the temperature sensors 16-1, 16-2, 16-3, 16-4, and also transfers the control information generated by the processor 72 to the distribution valve 22 and the water regulation valve. It is transmitted to 24 and the like.

<Control unit 70 of water heater 8>
FIG. 5 shows a configuration example of the control unit of the water heater 8.
The control unit 70 is composed of a computer, and includes, for example, a processor 80, a memory unit 82, a communication unit 84, and an input / output unit (I / O) 86.
The processor 80 executes arithmetic processing of the OS (Operating System) and the hot water supply control program stored in the memory unit 82. The memory unit 82 stores data necessary for hot water supply control in addition to the OS and control program, and temperature sensors 16-7, 16-8, 16 for detecting the temperature of hot water flowing through the water supply pipe 60 and the hot water outlet pipe 28. -9 detected temperature information, hot water flow rate information detected by the flow rate sensor 62, and the like are stored. The memory unit 82 includes a ROM (Read-Only Memory) and a RAM (Random-Access Memory). A storage element such as a hard disk device or a non-volatile memory for storing data is used in the memory unit 74. RAM constitutes an information processing work area.

The communication unit 84 is wirelessly or wiredly connected to, for example, the water heater remote controller 38 or the control unit of another water heater connected to the water heater system 2, receives temperature information of a hot water supply request, and the water heater. The operating state information of 8 is transmitted.
The I / O 86 acquires the detection information from the flow rate sensor 62 and the temperature sensors 16-7, 16-8, 16-9, and also transmits the control information generated by the processor 80 to the water control valve 68, the distribution valve 64, and the like. And send.

<Control status by hot water supply system>
FIG. 6 shows an example of a state of temperature change of hot water by a hot water supply system. Here, an example of the set temperature for the hot water storage unit 4 and the water heater 8 of the hot water supply system 2 is shown, but the present invention is not limited to such setting conditions.
In this hot water supply system, for example, the curan temperature (Tout), which is the required hot water supply temperature (TempHW), is set to 40 [° C.], and the threshold value of the temperature detected by the temperature sensor 16-3 is set as the threshold value of the heat storage state in the hot water storage tank 10. P is 65 [° C.]. Further, the temperature of the hot water flowing through the hot water supply pipes 28 and 30 through the water heater 8 is set to 60 [° C.]. The temperature of the water supply W is assumed to be 15 [° C.].
As for the heat storage state in the hot water storage tank 10, heat is consumed with the passage of time by continuing to discharge hot water from the hot water storage tank 10 in response to a hot water supply request, so that the hot water storage tank temperature (Tsto) decreases. The mixed water control valve 12 adjusts the mixing amount of the water supply W according to the hot water storage tank temperature (Tso), so that the mixing temperature (Tmix-tu) is set as the first set temperature. Temp1 = 60 [° C.] Is maintained. As a result, in the hot water supply system 2, the hot water HW that can respond to the hot water supply request is discharged from the hot water storage unit 4, so that the hot water HW is bypassed without operating the water heater 8 and is supplied to the curan 32 side through the hot water supply pipes 28 and 30. Shed. In the faucet 32, the hot water HW at the first set temperature (Temp1) and the hot water supply W are mixed and discharged.

Further, in the hot water supply system 2, when the hot water supply request continues and the hot water storage tank temperature (Tso) drops to the threshold value P at time t1, the mixing temperature (Tmix-tu) is set as the second set temperature for the mixed water control valve 12. The temperature is lowered to Temp2 = 50 [° C.]. This second set temperature (Temp2) is a temperature higher than the required hot water supply temperature. Further, the second set temperature (Temp2) is a temperature within the ignition start temperature range of the burner 52 mounted on the water heater 8. The ignition start temperature is, for example, a threshold temperature at which the burner 52 is ignited according to the temperature of the water flowing into the water heater 8 or the hot water. The range is a temperature lower than the threshold temperature set as the ignition start temperature. That is, in this hot water supply system 2, hot water is discharged from the mixed water control valve 12 at a temperature at which the water heater 8 which is an auxiliary heat source is activated when the hot water storage unit 4 is in a heat storage state capable of responding to the hot water supply request.
In the hot water storage unit 4, the mixing temperature (Tmix-tu) of the hot water storage unit 4 drops to Temp2 during the time X1 from the time t1 to the time t2 due to the change of the set temperature. As a result, the hot water flowing into the water heater 8 during the time X1 becomes lower than the ignition temperature of the burner 52, and the burner 52 ignites. In the hot water supply system 2, as the mixing temperature (Tmix-tu) becomes the second set temperature (Temp2), the water heater outlet temperature (Tmix-bb) detected by the temperature sensor 16-9 also decreases, and the time When it reaches T3, it becomes stable at the set temperature Temp2. At this time, since the second set temperature (Temp2) is higher than the temperature required for hot water supply, the faucet temperature (Tout) does not change.
Then, in the hot water supply system 2, for example, when the time X2 from the ignition of the burner 52 to t4 elapses, the auxiliary heating by the water heater 8 stabilizes, so that the water heater outlet temperature (Tmix-bb) is set to the first setting. It rises to the temperature (Temp1). After that, in the hot water supply system 2, even if the hot water storage tank temperature (Tsto) drops, the water heater outlet temperature (Tmix-bb) is maintained at the first set temperature (Temp1) by the auxiliary heating of the water heater 8. The curan temperature (Tout) can continue to maintain the hot water supply required temperature (TemppW).
At this time, the mixed water control valve 12 maintains the set temperature of the second set temperature (Temp2), and even if the water heater outlet temperature (Tmix-bb) starts to rise, the second set temperature (Temp2) Take a hot water at.

<About hot water supply control>
FIG. 7 shows an example of the hot water supply control process of the hot water storage unit. The processing procedure and processing content shown in FIG. 7 are examples, and the present invention is not limited to such a configuration. This hot water supply control is an example of the hot water supply method or program of the present invention.
In the hot water supply system 2, the hot water in the hot water storage tank 10 is discharged at the first set temperature (Temp1) set in the hot water storage tank remote controller 36 by the hot water supply control of the hot water storage unit 4 (S201). At this time, since hot water having a temperature corresponding to the hot water supply request is being discharged from the hot water storage unit 4, the water heater 8 is bypassed and auxiliary heating is not performed. Further, in the hot water storage unit 4, as the hot water supply control, as described above, the temperature of the hot water in the hot water storage tank 10, the first set temperature, and the water supply temperature are used to calculate the mixing ratio and the mixing control by the mixed water control valve 12. And so on.
Further, on the water heater 8 side, it may be determined whether or not to operate the water heater 8 based on, for example, the detected temperature of the temperature sensor 16-7 installed in the water supply pipe 60 and the detected flow rate of the flow rate sensor 62. ..

As a result of discharging hot water from the hot water storage unit 4, it is monitored whether or not the hot water storage tank temperature (Tsto) is, for example, the set temperature α or less of the hot water storage tank remote controller 36. This set temperature α is an example of the threshold value P of the heat storage state, and for example, it is determined whether or not the temperature is in the range of 5 [° C.] higher than the first set temperature (Temp1) input to the hot water storage tank remote controller 36. In the control unit 49, when the temperature of the hot water in the hot water storage tank 10 is not equal to or lower than the set temperature α (NO in S202), that is, when hot water having a temperature higher than the set temperature α is stored, only the hot water storage unit 4 side is used. Continue to supply hot water.
Further, when the temperature of the hot water in the hot water storage tank 10 is equal to or lower than the set temperature α (YES in S202), the control unit 49 controls the mixed water control valve 12 to start the auxiliary heating by the water heater 8 to and the hot water. The mixing temperature (Tmix-tu) of water is discharged at the temperature β set in the hot water storage tank remote controller 36 (S203). This temperature β is the second set temperature (Temp2), which is higher than the required hot water supply temperature, and is within the ignition start temperature range of the burner 52 installed in the water heater 8.
In the hot water supply system 2, the heat storage of the hot water storage unit 4 is preheated and used by lowering the mixing temperature, and hot water is supplied by heating using the combustion exhaust of the water heater 8 (S204).

<Hot water supply control on the 8 side of the water heater>
FIG. 8 shows an example of the control process of the water heater. The processing content or processing procedure shown in FIG. 8 is an example.
When the water heater operation is started (S301), the control unit 70 detects the entry temperature of hot or cold water flowing through the water supply pipe 60. The water heater operation also includes, for example, an initialization process and a monitoring process for the presence or absence of hot water supply. Then, when the temperature of the entered hot water is equal to or lower than the ignition temperature (minimum combustion capacity) of the water heater 8 (YES in S302), the burner 52 is ignited and the hot water supply heating is started (S303).

<Effect of the second embodiment>
According to such a configuration, the following effects can be obtained.
(1) By changing the set temperature of the hot water generated by the mixed water control valve 12 according to the heat storage state in the hot water storage tank 10 and starting the water heater, the hot water can be discharged at the required hot water supply temperature.
(2) By starting the auxiliary heating by the water heater 8 when the heat storage state can meet the hot water supply request, the hot water supply is not affected by the unstable hot water supply temperature at the start of the water heater 8.
(3) By starting the auxiliary heating before the hot water in the hot water storage tank 10 runs out, the user does not feel uncomfortable due to the decrease in the hot water temperature.
(4) The start control of the auxiliary heat source can be performed only by changing the set temperature at which hot water is discharged through the mixed water control valve 12 of the hot water storage unit 4, which enhances convenience.

[Third Embodiment]
FIG. 9 shows a configuration example of the hot water supply system 2 according to the third embodiment. In FIG. 9, the same parts as those in FIGS. 2 and 3 are designated by the same reference numerals.
In the second embodiment, the case where auxiliary heating is performed by a single water heater 8 is shown, whereas in the hot water supply system 2 shown in FIG. 9, a plurality of gas water heaters 8-1, 8-2, ... .. 8-N is installed in parallel with the hot water supply pipe 26 of the hot water storage unit 4.
In such a configuration, the gas water heaters 8-1, 8-2, ... 8-N have, for example, their respective control units 70 connected by wire or wirelessly, and gas is supplied according to the flow rate of the hot water supply request. Water heaters 8-1, 8-2, ... 8-N may be interlocked, or a gas water heater that operates and a gas water heater that pauses according to the flow rate of the hot water supply request 8-1, 8-2. 8-3, 8-4 ..., 8-N may be selected. In addition, the plurality of gas water heaters 8-1, 8-2, ... 8-N are, for example, a priority device that is always activated when a hot water supply request occurs, and an auxiliary heating amount is adjusted according to the hot water supply demand. Subordinates that operate to do so may be set.

Then, in the hot water supply control process, for example, the second set temperature set in the mixed water control valve 12 of the hot water storage unit 4 may be adjusted according to the number of gas water heaters set according to the flow rate of the hot water supply request. That is, the minimum combustion number of the water heater may change depending on the number of gas water heaters 8-1, 8-2, 8-3, ... 8-N to be operated. In the hot water supply system 2, for example, hot water is branched into approximately the same amount with respect to the parallel gas water heaters 8-1, 8-2, and 8-3. Therefore, when a large number of water heaters that are ready for operation are activated, it may be necessary to adjust the flow rate of hot water discharged from the hot water storage unit 4. In this case, the hot water storage unit 4 may set a threshold value P calculated according to a required flow rate and a temperature measurement position in the hot water storage tank 10 with respect to the heat storage state in the hot water storage tank 10.

In addition, in the hot water supply system 2, for example, when the heat storage state becomes less than the threshold value with respect to the hot water supply demand, only a part of the plurality of gas water heaters 8-1 and 8-2 is started in advance, and the hot water discharge temperature is reached. When the temperature is stabilized, a plurality of water heaters 8 for heating the required flow rate may be started.

<Effect of the third embodiment>
According to this third embodiment, any of the following effects can be obtained.
(1) By providing a plurality of gas water heaters 8-1, 8-2, ... 8-N, the auxiliary heating capacity can be increased, and the hot water supply capacity of the gas water heaters 8-1 to 8-3 fluctuates. On the other hand, it is possible to realize a preheated water supply function with a margin.
(2) By using multiple gas water heaters 8-1, 8-2, ..., Hot water supply processing that meets a large amount of hot water supply demand can be performed.

[Comparative example]

Next, a comparative example of the state of hot water supply processing in the conventional hot water supply system will be described.
FIG. 10 shows a comparative example of a hot water supply system.
Such a hot water supply system includes, for example, a hot water storage unit and a water heater as an auxiliary heating means, as in the present application. Then, in the hot water supply control, for example, as shown in FIG. 10, the heat storage state in the hot water storage tank is determined by the hot water storage tank temperature (Tsto), and hot water is supplied based on the determination result. Then, in the hot water supply system, the temperature drops below the set temperature of Temp1 due to the use of hot water in the hot water storage tank, and follows, for example, the temperature (Tst) in the hot water storage tank 10 drops at time ta. The mixing temperature (Tmix-tu) at which hot water is discharged through the mixed water control valve 12 also decreases at about the same temperature as the hot water storage tank. Then, as the mixing temperature (Tmix-tu) continues to decrease, the temperature falls within the ignition temperature range of the water heater 8 at a predetermined time ta. Then, even if the predetermined time tb is reached, the operation of the water heater 8 is not stabilized, the water heater outlet temperature (Tmix-bb) is lowered, and the temperature becomes lower than the hot water supply required temperature TemppHW.

Then, when the operation of the water heater 8 is started and the predetermined time reaches tk, the operating state of the water heater 8 is stabilized, so that the water heater outlet temperature (Tmix-bb) rises and Temp1 which is the set temperature. It is possible to get hot water at.

In this way, in the hot water supply system and hot water storage unit that auxiliary heat the hot water in the hot water storage tank by the water heater, if the combustion of the water heater is started when the heat storage in the hot water storage tank decreases, the response of the auxiliary heating In addition to its poor properties, it can only produce hot water that is cooler than the minimum required hot water temperature. On the other hand, according to the hot water supply system and the hot water storage unit of the present invention, as shown in FIG. 6, the combustion start timing of the auxiliary combustion unit is advanced, and the water heater operates when the heat storage in the hot water storage tank is sufficient. To start. As a result, even if there are factors such as instability of operation when the water heater 8 is started, hot water that can meet the hot water supply request can be discharged from the hot water supply system 2, and it is possible to prevent the temperature of the hot water from the faucet from dropping. ..

[Other Embodiments]
(1) In the above embodiment, the case where the hot water storage tank 10 is single is shown, but the present invention is not limited to this. In this hot water supply system 2, for example, a plurality of hot water storage tanks can be connected in series to store heat in a huge hot water storage capacity. Then, in the hot water storage tank 10, for example, the installation position of the temperature sensor 16-3 for monitoring the heat storage state in the hot water storage tank 10 is set according to the distance to the hot water supply load supported by the hot water supply system 2 and the amount of hot water to be used. do it.

As described above, the most preferable embodiment of the present invention has been described. The present invention is not limited to the above description. Various modifications and modifications can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the form for carrying out the invention. Needless to say, such modifications and modifications are included in the scope of the present invention.

The present invention lowers the set temperature of the hot water discharged from the hot water storage unit at the stage where the amount of heat in the range corresponding to the hot water supply request is stored in the heat storage tank, and starts the water heater which is an auxiliary heat source. It is useful because the hot water can be discharged at a temperature according to the hot water supply request without showing the influence of the unstable state in the heat treatment during the start-up period of the above.

2 Hot water supply system 4 Hot water storage unit 6 Heat pump 8 Water heater 10 Hot water storage tank 12 Mixed water control valve 14, 60 Water supply pipe 16-1, 16-2, 16-3, 16-4, 16-5, 16-6, 16- 7, 16-8, 16-9 Temperature sensor 18, 26 Hot water supply pipe 20, 46, 66 Bypass pipe 22, 64 Distribution valve 24, 68 Water regulation valve 28, 30 Hot water supply pipe 32 Callan 34 Water supply pipe 36 Hot water storage tank Remote control 38 Water heater Remote control 40 Water flow sensor 42 Heat supply pipe 44 Heat supply return pipe 47 Switching valve 48 Circulation pump 49, 70 Control unit 50 Heat exchanger 52 Burner 54 Mixing control valve 62 Flow sensor 72, 80 Processor 74, 82 Memory Section 76 System communication section 78, 86 Input / output section (I / O)
84 Communication section

Claims (17)

The process of acquiring the heat storage status information of the hot water in the hot water storage tank,
In the mixing section where water is mixed with the hot water discharged from the hot water storage tank, the step of flowing the hot water adjusted to the first set temperature to the auxiliary heating means side and
When the heat storage state of the hot water storage tank is such that hot water can be supplied in response to the hot water supply request and is less than the threshold value, the set temperature of the mixing unit is changed to the second set temperature lower than the first set temperature. The process to change and
A hot water supply method characterized by including. The hot water supply method according to claim 1, further comprising a step of adjusting the temperature of the second set temperature to within the range of the ignition start temperature of the auxiliary heating means and discharging hot water from the mixing unit. Further, a step of detecting the temperature of the hot water discharged from the hot water storage tank and
A step of calculating the mixing ratio of water based on at least the first set temperature or the second set temperature, the water supply temperature, and the temperature of the hot water discharged from the hot water storage tank.
A step of controlling the amount of water supplied and the amount of hot water discharged from the hot water storage tank based on the calculated mixing ratio, and
The hot water supply method according to claim 1 or 2, wherein the hot water supply method comprises. Further, a step of detecting a mixed hot water temperature, which is a mixture of hot water and water discharged from the hot water storage tank, and
A step of determining whether or not the mixed hot water outlet temperature is higher than the hot water supply required temperature and within the range of the ignition start temperature of the auxiliary heating means.
The hot water supply method according to any one of claims 1 to 3, wherein the hot water supply method comprises. The hot water supply method according to claim 2 or 4, wherein the range of the ignition start temperature is such that the temperature of water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature. A hot water storage tank for storing heated water and
The heat storage state information acquisition means for acquiring the heat storage state information of the hot water in the hot water storage tank, and
A mixing unit that mixes water with the hot water discharged from the hot water storage tank and flows the hot water adjusted to the first set temperature to the auxiliary heating means side.
When the heat storage state of the hot water storage tank is such that hot water can be supplied in response to the hot water supply request and is less than the threshold value, the set temperature of the mixing unit is changed to the second set temperature lower than the first set temperature. The control unit to change and
A hot water storage unit characterized by being equipped with. The second set temperature is within the range of the ignition start temperature of the auxiliary heating means.
The hot water storage unit according to claim 6, wherein the control unit adjusts the temperature of the hot water to the second set temperature and flows the hot water. The hot water storage unit according to claim 7, wherein the range of the ignition start temperature is such that the temperature of water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature. Further, a tank hot water temperature sensor for detecting the temperature of hot water discharged from the hot water storage tank is provided.
The control unit calculates the mixing ratio of water based on at least the first set temperature or the second set temperature, the water supply temperature, and the temperature of the hot water discharged from the hot water storage tank, and calculates the water supply amount and the hot water storage. The hot water storage unit according to any one of claims 6 to 8, wherein the amount of hot water discharged from the tank is controlled. A hot water storage tank for storing heated water and
The heat storage state information acquisition means for acquiring the heat storage state information of the hot water in the hot water storage tank, and
A mixing unit that mixes water with the hot water discharged from the hot water storage tank and flows the hot water adjusted to the first set temperature to the auxiliary heating means side.
When the heat storage state of the hot water storage tank is such that hot water can be supplied in response to the hot water supply request and is less than the threshold value, the set temperature of the mixing unit is changed to the second set temperature lower than the first set temperature. The control unit to change and
A hot water supply system characterized by being equipped with. The tenth aspect of the present invention, wherein the mixing portion is changed to the second set temperature to adjust the temperature of the hot water within the range of the ignition start temperature of the auxiliary heating means. Hot water supply system. The hot water supply system according to claim 11, wherein the range of the ignition start temperature is such that the temperature of water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature. Further, a tank hot water temperature sensor for detecting the temperature of hot water discharged from the hot water storage tank is provided.
The control unit calculates the mixing ratio of water based on at least at least the first set temperature or the second set temperature, the water supply temperature, and the temperature of the hot water discharged from the hot water storage tank, and calculates the water supply amount and the water supply amount. The hot water supply system according to any one of claims 10 to 12, wherein the amount of hot water discharged from the hot water storage tank is controlled. A program realized by a computer
A function to acquire heat storage status information of hot water in the hot water storage tank, and
A mixing unit that mixes water with hot water discharged from the hot water storage tank, and has a function to adjust the hot water to the first set temperature and let it flow to the auxiliary heating means side.
When the heat storage state of the hot water storage tank is such that hot water can be supplied in response to the hot water supply request and is less than the threshold value, the set temperature of the mixing unit is changed to the second set temperature lower than the first set temperature. The ability to change and
A program characterized by including. The program according to claim 14, wherein the mixing unit includes a function of adjusting the temperature of the hot water within the range of the ignition start temperature of the auxiliary heating means by changing the temperature to the second set temperature. .. The program according to claim 15, wherein the range of the ignition start temperature is such that the temperature of water or hot water flowing into the auxiliary heating means is lower than the ignition start temperature. Furthermore, a function to acquire the detection temperature information of the hot water discharged from the hot water storage tank and
A function of calculating the mixing ratio of water based on at least the first set temperature or the second set temperature, the water supply temperature, and the temperature of the hot water discharged from the hot water storage tank.
A function to control the amount of water supplied and the amount of hot water discharged from the hot water storage tank based on the calculated mixing ratio, and
The program according to any one of claims 14 to 16, wherein the computer is executed.

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