JP7340283B2 - Methods, systems, programs and devices of hot water supply - Google Patents

Description

The present invention relates to a technology for controlling a heat exchanger that exchanges heat between a heat medium in a heat storage tank and water supply.

Exhaust heat is exchanged with a heat medium, and this heat medium is stored in a heat storage tank for heat storage. This heat storage tank employs a so-called hierarchical heat storage method in which a low-temperature heat medium is heated from the lower layer, raised to a high temperature, and returned to the upper layer of the heat storage tank with an upward gradient from the lower layer to the upper layer. To utilize heat storage from a heat storage tank using such a heat storage method, a heat medium is taken out from the upper layer side and heat exchanged with hot water.
Regarding such heat exchange, when heat is exchanged from the heat medium in the heat storage tank to the feed water, depending on the amount of heat stored in the heat storage tank, an insufficient amount of heat may occur when heating the feed water to a set temperature. It is known to compensate for this insufficient amount of heat with an auxiliary heating source and raise the hot water temperature to a set temperature (Patent Document 1).

Japanese Patent Application Publication No. 2011-214793

By the way, the technology described in Patent Document 1 can efficiently utilize the heat stored in the heat storage tank to heat the water supply, and its practicality is highly evaluated.
However, even if there is little heat stored in the heat storage tank, if it is to be fully utilized for heating the feed water, the amount of heat medium circulated with respect to the feed water flowing into the heat exchanger will be increased to the limit. In such control, pressure loss cannot be ignored in a heat exchanger such as a plate heat exchanger because the water supply passage is narrow.
SUMMARY OF THE INVENTION In view of the above-mentioned problems, an object of the present invention is to achieve efficient hot water supply by reducing pressure loss in a heat exchanger.

In order to achieve the above object, one aspect of the hot water supply method of the present invention includes a step of exchanging heat generated by power generation with a heat medium and storing the heat medium in a heat storage tank, and removing the heat medium from the heat storage tank. a step of circulating the heat medium through a heat exchanger and exchanging heat between the heat of the heat medium and the feed water; and when the heat medium of the heat storage tank can exchange heat with the feed water, the feed water before heat exchange is passed through the heat exchanger. and a step of mixing the supplied water distributed to the bypass path with hot water obtained by the heat exchanger, a first set temperature, and a first set temperature that is lower than the first set temperature by a predetermined temperature. The second set temperature is set, and it is determined based on the temperature of the heat medium whether hot water can be tapped at the first set temperature, and if hot water can be tapped, the water supply distributed to the bypass path and the heat exchanger are The obtained hot water is mixed with the hot water and discharged at the first set temperature, and if hot water cannot be discharged, the temperature is switched to the second set temperature, and the hot water is mixed with the hot water distributed to the bypass path and the hot water obtained by the heat exchanger. The amount of water supplied is mixed with the hot water, heated to the second set temperature, and flowed to the auxiliary heating section, heated in the auxiliary heating section, and discharged at the first set temperature, and flowed to the heat exchanger. and reducing the pressure loss of the heat exchanger.
This hot water supply method may further include the step of increasing the amount of water supplied distributed to the bypass path from the amount of water supplied to the heat exchanger when hot water is dispensed at the second set temperature.
In order to achieve the above object, one aspect of the hot water supply system of the present invention includes a heat storage tank that stores a heat medium with which heat generated during power generation has been exchanged, and a heat storage tank that circulates the heat medium from the heat storage tank. and a heat exchanger for exchanging heat between the heat of the heat storage tank and the feed water, and when the heat medium of the heat storage tank can exchange heat with the feed water, the feed water before heat exchange is caused to flow through the heat exchanger and the bypass path, and the bypass mixing means for mixing the water supply distributed to the heat exchanger with the hot water obtained by the heat exchanger; a first set temperature; and a second set temperature that is lower than the first set temperature by a predetermined temperature. and determining whether hot water can be tapped at the first set temperature based on the temperature of the heating medium, and if hot water can be tapped, mixing the supplied water distributed to the bypass path and the hot water obtained by the heat exchanger. If hot water cannot be dispensed, the temperature is switched to the second set temperature , and the supplied water distributed to the bypass path and the hot water obtained by the heat exchanger are mixed. heating the water to the second set temperature and flowing it to an auxiliary heating section, heating the water at the auxiliary heating section and discharging the water at the first set temperature, and reducing the amount of water to be distributed to the heat exchanger. and a control unit that reduces pressure loss of the heat exchanger.

In order to achieve the above object, one aspect of the program of the present invention is a program for a computer to execute, which has a function of acquiring temperature information of a heat medium to be circulated from a heat storage tank to a heat exchanger, and a function of acquiring temperature information of a heat medium to be circulated from a heat storage tank to a heat exchanger. A function of controlling the opening degree on the heat exchanger side and the opening degree on the bypass passage side of the mixing valve that allows the heat medium to flow into the heat exchanger and the bypass passage, and when the heat medium of the heat storage tank can exchange heat with the water supply, A first set temperature and a second set temperature lower than the first set temperature by a predetermined temperature are set, and whether hot water can be tapped at the first set temperature is determined based on the temperature of the heating medium, and whether hot water can be tapped or not is determined. If there is, the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed and hot water is discharged at the first set temperature, and if hot water cannot be discharged, the second set temperature is set. , the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed, heated to the second set temperature, flowed to the auxiliary heating section, and heated in the auxiliary heating section. and causing the computer to perform a function of dispensing hot water at the first set temperature and reducing a distribution amount of the feed water flowing to the heat exchanger to reduce pressure loss in the heat exchanger.

In order to achieve the above object, according to one aspect of the water heater of the present invention, the heat medium is circulated from a heat storage tank that stores the heat medium with which the heat generated during power generation has been exchanged, and the heat and the supplied water are heated. When the heat exchanger to be exchanged and the heat medium of the heat storage tank can exchange heat with the feed water, the feed water before heat exchange is caused to flow through the heat exchanger and the bypass path, and the feed water is distributed to the bypass path. and hot water obtained in the heat exchanger; a first set temperature; and a second set temperature that is lower than the first set temperature by a predetermined temperature; It is determined whether hot water can be tapped based on the temperature of the heating medium , and if hot water can be tapped, the supplied water distributed to the bypass path and the hot water obtained by the heat exchanger are mixed to meet the first setting. If hot water cannot be dispensed, the temperature is switched to the second set temperature, and the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed to reach the second set temperature. The hot water is heated to a temperature of 100% and flows to an auxiliary heating section, is heated in the auxiliary heating section and discharged at the first set temperature , and the distribution amount of the feed water to be flowed to the heat exchanger is reduced to reduce the pressure loss of the heat exchanger. and a control unit that reduces.

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

(1) Even when the heat storage in the heat storage tank does not reach the amount of heat required to produce hot water at the set temperature, the heat medium in the heat storage tank is used, so the amount of heat from the heat medium can be used effectively.
(2) If the heat stored in the heat storage tank does not reach the amount of heat required to produce hot water at the set temperature, the amount of water supplied for heat exchange flowing to the heat exchanger can be reduced, and the pressure loss on the heat exchanger side can be reduced.

(3) Circulation pumps are generally used to circulate heat medium through heat exchangers, but since the amount of circulation can be reduced, excessive rotation speed of the circulation pump can be suppressed, reducing consumption by the circulation pump. Electric power can be reduced.
(4) The stratified state of the heat medium stored in the heat storage tank is not disturbed, and the heat amount of the heat medium can be used efficiently.

FIG. 1 is a diagram showing a hot water supply system according to an embodiment. It is a figure for explaining temperature control of a hot water supply part. It is a flowchart which shows the processing procedure of hot water supply control. 1 is a diagram showing a hot water supply system according to Example 1. FIG. It is a block diagram showing a control system. A is a table showing the water supply temperature, temperature after heat exchange, heat exchange water amount, and minimum heat medium temperature when obtaining the hot water supply setting temperature Ts1 = 35 [°C], B is a table showing the water supply temperature when obtaining the hot water supply setting temperature Ts1 = 40 [°C] Table showing the water supply temperature, temperature after heat exchange, amount of heat exchanged water, and minimum heat medium temperature, C is the water supply temperature, temperature after heat exchange, amount of heat exchanged water, and minimum heat medium when obtaining the hot water supply setting temperature Ts1 = 45 [°C] This is a table showing temperatures. It is a figure which shows the minimum heat medium temperature with respect to the water supply temperature when hot water supply setting temperature is used as a parameter. FIG. 3 is a diagram for explaining a hot water supply operation corresponding to heat storage. It is a flowchart comprehensively showing the processing procedure of the hot water supply system. 3 is a flowchart showing the processing procedure of the fuel cell unit. It is a flowchart which shows the processing procedure of a hot water supply unit. It is a flowchart which shows the processing procedure of a backup hot water supply unit. It is a figure which shows the pressure loss with respect to a passing flow rate ratio. FIG. 3 is a diagram showing a hot water supply system according to a second embodiment. FIG. 3 is a diagram showing a hot water supply system according to a third embodiment.

[One embodiment]
FIG. 1 shows a hot water supply system according to an embodiment of the present invention. The configuration shown in FIG. 1 is an example, and the present invention is not limited to such a configuration.
The hot water supply system 2 includes a hot water supply section 4 and an auxiliary heating section 6. The hot water supply section 4 exchanges the heat of the heat medium ME1 with the water supply W, and guides the hot water HW to the auxiliary heating section 6. In the auxiliary heating section 6, if the hot water HW from the hot water supply section 4 is at the set temperature, the hot water HW is discharged as is, and if it is below the set temperature, the temperature is raised to the set temperature by auxiliary heating, and the hot water HW at the set temperature is heated. Take out the hot water.

The hot water supply section 4 is equipped with a heat storage tank 8, a pump 9, a heat exchanger 10, and a water amount adjustment section 12. Heat storage tank 8 stores heat using heat medium ME1. The heat medium ME1 taken out from the lower layer side of the heat storage tank 8 is circulated to the heat source side (not shown) and heated, and the heated heat medium ME1 is returned to the upper layer side of the heat storage tank 8. Thereby, heat is stored in the heat storage tank 8 in a stratified state rising from the lower layer to the upper layer.
The pump 9 is operated when exchanging the heat of the heat medium ME1 to the water supply W, and circulates the heat medium ME1 through the heat exchanger 10.
For example, a plate heat exchanger is used as the heat exchanger 10. During heat exchange, the heat medium ME1 taken out from the upper layer side of the heat storage tank 8 to the circulation path 13 is circulated through the circulation path 13 to the heat exchanger 10 by operating the pump 9, and after heat exchange, the heat medium ME1 is taken out from the upper layer side of the heat storage tank 8 to the heat exchanger 10. returned to the side.

The water amount adjustment unit 12 is an example of a water amount adjustment means for the heat exchanger 10, and distributes the water supply W to the heat exchanger 10 and the bypass pipe 16, which is an example of a bypass path, and adjusts the amount of water flowing through the heat exchanger 10. The water supply W from the water supply pipe 14 flows to the inlet side of the heat exchanger 10 through the water amount adjustment section 12 or flows to the outlet pipe 18 from the bypass pipe 16. In this water amount adjustment section 12, the control section 20 is equipped with a mixing valve M1 whose opening degree is controlled, and the distribution amount of the feed water W flowing into the heat exchanger 10 and the bypass pipe 16 is adjusted.
The temperature of the heat medium ME1 circulating from the heat storage tank 8 to the heat exchanger 10 is detected by a temperature sensor 22. The temperature of the hot water HW obtained by mixing the hot water HW in the outlet pipe 18 with the water supply W in the bypass pipe 16 is detected by the temperature sensor 24 .

Water supply W or hot water HW is supplied from this hot water supply section 4 to an auxiliary heating section 6 . The auxiliary heating unit 6 performs auxiliary heating of the water supply W or the hot water HW when the temperature of the water supply W or the hot water HW is low. This auxiliary heating section 6 is equipped with a heat exchanger 26 and a heat exchanger 28. The heat exchanger 26 exchanges heat between the water supply W or hot water HW supplied from the hot water supply section 4 through the water supply pipe 30 and the heat medium ME2. Heat exchanger 28 exchanges heat from heat source 34 with heat medium ME2. The temperature sensor 32 detects the temperature of the water supply W or hot water HW passing through the water supply pipe 30. A bypass pipe 36 is branched off from the water supply pipe 30, and a water volume adjustment unit 38 including the bypass pipe 36 and a mixing valve M2 is provided, and supply water W or hot water HW is discharged from the water supply pipe 30 according to the opening degree of the mixing valve M2. The hot water is mixed with the hot water HW in the pipe 40 and discharged.

The control unit 20 determines whether hot water can be tapped at the first set temperature Ts1 based on the detected temperature of the heating medium ME1, and if hot water cannot be tapped at the set temperature Ts1, the controller 20 sets a second set temperature Ts2 (<Ts1) lower than the set temperature Ts1. ), and the distribution amount of the water supply W flowing into the heat exchanger 10, which is adjusted by the water amount adjustment unit 12, is reduced from that at the time of hot water discharge at the set temperature Ts1. The set temperature Ts1 is, for example, a temperature arbitrarily set by the user using a remote control device, and is stored in the storage means. On the other hand, the set temperature Ts2 is a temperature set based on the judgment of the control unit 20, and is stored in the storage means and read out as necessary.

According to such a hot water supply system 2, hot water HW is obtained by heating the supply water W by heat exchange with the heat medium ME1, that is, hot water HW whose temperature is higher than the set temperature Ts1 by a predetermined temperature α1 (for example, 6 [°C]) (Ts1+α1). and unheated water supply W are mixed to supply hot water at a set temperature Ts1.
Regarding this control, reference is made to FIG. 2 which schematically shows the hot water supply section 4.
a) The rotation speed of the pump 9 is controlled so that the detected temperature To1 (temperature after heat exchange), which is the temperature of the hot water HW after passing through the heat exchanger 10, becomes the temperature (Ts1+α1). If To1>(Ts1+α1), the rotation speed of the pump 9 is decreased, and if To1<(Ts1+α1), the rotation speed of the pump 9 is increased.
b) Regarding the flow path of the water volume adjustment unit 12, if the heat exchanger 10 side port of the mixing valve M1 is set as route A, and the bypass pipe 16 side port of the mixing valve M1 is set as route B, the detected temperature Tm1 becomes the set temperature Ts1. The flow ratio (mixing ratio) of route A and route B is controlled as follows.
The relationship between the detected temperature To1 and the detected temperature Ti1 of the water supply W is usually To1>Ti1. Therefore, in controlling the flow rate, if Tm1>Ts1, the flow rate of route B is increased, and if Tm1<Ts1, the flow rate is increased. , control is performed to increase the flow rate ratio of route A.

Here, when the detected temperature T1 of the heat medium ME1 decreases, the rotation speed of the circulation pump 9 increases due to the control in a), and the detected temperature T1 decreases to a temperature at which the detected temperature To1 cannot maintain the temperature (Ts1+α1). When the rotation speed shifts to , the rotation speed of the circulation pump 9 reaches the upper limit rotation speed.
In the control b), if the detected temperature To1 is maintained at the temperature (Ts1+α1), the control continues, but as the detected temperature To1 decreases, the flow rate ratio of the A route increases, and eventually the A The flow rate ratio of the route will reach 100%.
In order to improve the increase in the rotation speed of the pump 9, in Japanese Patent No. 5577135, when the detected temperature T1 is lower than a predetermined temperature, the detected temperature To1 is lowered to a predetermined temperature α2 (for example, 5 [° C.]) than the detected temperature T1. The temperature is controlled so that the detected temperature To1=(T1-α2). Thereby, excessive increase in the rotational speed of the pump 9 can be prevented. However, when mixing control is performed so that the detected temperature Tm1 becomes the set temperature Ts1, the flow rate ratio of route A increases as the detected temperature To1 decreases, and the pressure loss of the water supply W tends to increase. Become.

Therefore, at the control switching timing, the set temperature Ts1 is switched to a lower set temperature Ts2, and this set temperature Ts2 is switched to a temperature between the detected temperature To1 and the detected temperature Ti1 as a realizable temperature. For example, as the set temperature Ts2,
Ts2=(To1+Ti1)/2=(T1-α2+Ti1)/2
, the flow rate ratio of route A and route B becomes 50%.
In the control for switching from the set temperature Ts1 to Ts2 in this way, hot water supply control that controls the mixing valve M1 can be used in combination while preventing hunting and the like so that the detected temperature Tm1 becomes a predetermined temperature.
Therefore, the set temperatures Ts1 and Ts2 are switched according to the detected temperature T1 of the heat medium ME1 in the heat storage tank 8, and hot water is supplied by the hot water supply section 4, hot water is supplied by the hot water supply section 4 and the auxiliary heating section 6, and hot water is supplied only by the auxiliary heating section 6. .
(1) When the water supply W can be heated to the set temperature Ts1 by the heating medium ME1: Hot water can be supplied to the set temperature Ts1 only by the hot water supply unit 4 without using auxiliary heating by the auxiliary heating unit 6.
(2) When the detected temperature T1 of the heating medium ME1 is higher than the temperature of the water supply W, but the water supply W cannot be heated to the set temperature Ts1: By using auxiliary heating by the auxiliary heating section 6, it is possible to supply hot water at the set temperature Ts1. be.

(3) When the detected temperature T1 of the heat medium ME1 is equal to the temperature of the feed water W and the feed water W cannot be heated even if heat is exchanged from the heat medium ME1 to the feed water W, that is, when there is no heat storage in the heat medium ME1: It is possible to supply hot water at the set temperature Ts1 using only the auxiliary heating section 6 without using heating by the hot water supply section 4. In this control, switching between the above (1) and the above (2) may be performed using, for example, the relationship between the feed water temperature and the minimum heat medium temperature shown in FIG. In (3) above, the relationship of detected temperature of heating medium≦(supply water temperature+α2) may be used.
In such control, the mixing valve M1 is normally controlled so that the hot water output temperature becomes the set temperature Ts1, but there is a case where hot water cannot be discharged at the set temperature Ts1 due to certain conditions, that is, heat storage in the heating medium ME1. , the set temperature Ts1 is switched to a lower set temperature Ts2, and the mixing ratio of the mixing valve M1 is forcibly changed by this set temperature Ts2.

<Hot water supply control>
FIG. 3 shows a processing procedure for hot water supply control of this hot water supply system 2.
The detected temperature of the heat medium ME1 is taken in (S11), and based on this detected temperature, it is determined whether hot water can be tapped at the set temperature Ts1 (S12).
If hot water can be dispensed at the set temperature Ts1 (YES in S12), hot water HW at the set temperature Ts1 is generated under the control of the water amount adjustment section 12 (S13). In this case, since the hot water HW at the set temperature Ts1 is supplied from the hot water supply unit 4, the auxiliary heating unit 6 does not shift to the auxiliary heating mode (YES in S17), and the hot water HW at the set temperature Ts1 is supplied from the hot water outlet pipe 40 (FIG. 1). Hot water HW is obtained (S18).

If hot water cannot be obtained at the set temperature Ts1 (NO in S12), it is determined whether the detected temperature T1 of the heat medium ME1 is a temperature at which heat exchange with the water supply W is possible (S14). If the detected temperature T1 of the heat medium ME1 is a temperature at which heat exchange with the water supply W is possible (YES in S14), the current set temperature Ts1 is switched to the set temperature Ts2, and the heat exchanger 10 is adjusted by the water amount adjustment unit 12. The distribution amount of the water supply W flowing into the water is reduced from that at the time of tap water at the set temperature Ts1 (S15).
If the detected temperature T1 of the heat medium ME1 is a temperature at which heat exchange with the feed water W is not possible (NO in S14), the water is flowed from the hot water supply section 4 to the auxiliary heating section 6 without passing the water supply W through the heat exchanger 10 ( S16).
The auxiliary heating unit 6 determines whether the supply water W or hot water HW flowing into the water supply pipe 30 is equal to or higher than the set temperature Ts1 (S17). If the temperature is equal to or higher than the set temperature Ts1 (YES in S17), hot water is supplied without performing auxiliary heating (S18). If it is less than the set temperature Ts1 (NO in S17), the system shifts to the auxiliary heating mode, heats the supplied water W or hot water HW by exchanging heat with the heat medium ME2, and heats it up to supply hot water at the set temperature Ts1 (S19). ).

<Effects of one embodiment>
According to this embodiment, the following effects can be obtained.
(1) When the hot water HW at the set temperature Ts1 cannot be obtained in the hot water supply section 4, the set temperature Ts1 is switched to a lower set temperature Ts2, and the amount of water flowing to the heat exchanger 10 on the side of the hot water supply section 4 is suppressed. 10 can be reduced.
(2) When hot water HW at the set temperature Ts1 cannot be obtained in the hot water supply section 4, hot water HW heated to the set temperature Ts1 can be supplied by auxiliary heating in the auxiliary heating section 6.
(3) Since the amount of water supplied to the heat exchanger 10 is adjusted according to the heat storage, the utilization efficiency of the heat medium ME1 in the heat storage tank 8 is increased, and the stratification state on the heat storage tank 8 side is not disturbed.

FIG. 4 shows a hot water supply system according to the first embodiment. In FIG. 4, the same parts as in FIG. 1 are given the same reference numerals.
The hot water supply system 2 of Example 1 includes a fuel cell unit 42, a hot water supply unit 44, and a backup hot water supply unit 46.
The fuel cell unit 42 is equipped with a fuel cell 48, a heat exchanger 50, and a circulation pump 52. The fuel cell 48 is an example of a heat source, and uses heat generated during power generation as a heat source. The heat exchanger 50 exchanges heat from the exhaust gas ME3 of the fuel cell 48 with the heat medium ME1 on the heat storage tank 8 side. The circulation pump 52 is installed in the circulation path 54 of the heat medium ME1, and when driven, circulates the heat medium ME1 from the lower side of the heat storage tank 8 to the heat exchanger 50, and also transfers the heat medium ME1 after heat exchange to the heat storage tank 8. Return to the upper layer.
When the fuel cell 48 generates electricity, the circulation pump 52 is driven, the heat medium ME1 is circulated from the lower side of the heat storage tank 8 to the heat exchanger 50, and the heat of the exhaust gas ME3 is exchanged with the heat medium ME1. The medium ME1 is returned to the upper layer side of the heat storage tank 8. Thereby, stratified heat storage is performed in the heat storage tank 8. A temperature sensor 56 is installed on the inlet side of the heat exchanger 50, and detects the temperature of the heat medium ME1 on the lower layer side of the heat storage tank 8. A temperature sensor 58 is installed on the exit side of the heat exchanger 50, and detects the temperature of the heat medium ME1 returned to the upper layer side of the heat storage tank 8.

The hot water supply unit 44 is equipped with a heat storage tank 8 and a plate heat exchanger 60. A circulation path 62 through which the heat medium ME1 of the heat storage tank 8 flows through the plate heat exchanger 60 is equipped with a heating pump 64 and a temperature sensor 22. When the heating pump 64 is driven, the heat medium ME1 circulates from the upper layer of the heat storage tank 8 to the plate heat exchanger 60 and is returned to the lower layer of the heat storage tank 8. The temperature sensor 22 detects the temperature of the heat medium in the upper layer of the heat storage tank 8 . A temperature sensor 66 installed in the heat storage tank 8 detects the temperature of the heat medium ME1 inside the tank.
A water pipe or the like is connected to the water supply pipe 14, and water supply W is supplied thereto. The water supply pipe 14 is equipped with a mixing valve 68 , a water flow sensor 70 , and a temperature sensor 72 , and is connected to the hot water outlet pipe 18 via the mixing valve 68 and the bypass pipe 16 . The hot water outlet pipe 18 is equipped with a water control valve 74 and temperature sensors 76 and 78. The bypass pipe 16 allows the water supply W separated by the mixing valve 68 to flow into the hot water outlet pipe 18 side. The water control valve 74 controls the amount of hot water HW or water supply W discharged from the hot water supply pipe 18 . Temperature sensor 76 detects the hot water temperature on the outlet side of plate heat exchanger 60. The temperature sensor 78 detects the temperature of the hot water HW obtained by mixing the hot water HW and the supply water W.

The backup hot water supply unit 46 is equipped with a plate heat exchanger 80 and a heat exchanger 82. The plate heat exchanger 80 is provided with a water supply pipe 30 on its inlet side and a hot water outlet pipe 40 on its outlet side. The water supply pipe 30 is supplied with water supply W or hot water HW from the hot water supply unit 44, and is equipped with a temperature sensor 84, a water amount sensor 85, a water control valve 86, and is connected to a mixing valve 88 that branches the bypass pipe 36. Temperature sensor 84 detects the temperature of hot water HW or water supply W flowing from hot water supply unit 44 . The water amount sensor 85 detects the amount of hot water HW or water supply W flowing from the hot water supply unit 44, and the water control valve 86 controls the amount of water.
The hot water outlet pipe 40 is equipped with temperature sensors 90 and 92. Temperature sensor 90 detects the hot water temperature on the outlet side of plate heat exchanger 80. The temperature sensor 92 detects the temperature of the hot water HW that is a mixture of the supplied water W or hot water HW from the bypass pipe 36 and the hot water HW on the outlet pipe 40 side.
The plate heat exchanger 80 is equipped with a circulation path 94 to circulate the heat medium ME2. The circulation path 94 is equipped with a heat exchanger 82, a circulation pump 96, an open tank 98, and a temperature sensor 100. The circulation pump 96 circulates the heat medium ME2 through the circulation path 94 when driven. Plate heat exchanger 80 exchanges heat of heat medium ME2 with supply water W or hot water HW. Heat exchanger 82 exchanges combustion heat of burner 102 with heat medium ME2. The open tank 98 absorbs volume fluctuations of the heat medium ME2 circulating in the circulation path 94.

<Control unit 20 of hot water supply system 2>
FIG. 5 shows the control unit 20 (FIG. 1) of the hot water supply system 2. As shown in FIG. The control section 20 includes a battery control section 104, a hot water supply unit control section 106, a backup control section 108, and a remote control control section 110. The battery control section 104 controls the fuel cell unit 42. Hot water supply unit control section 106 controls hot water supply unit 44 . Backup control section 108 controls backup hot water supply unit 46. The remote control control section 110 is included in the remote control device and communicates with the battery control section 104, the hot water supply unit control section 106, and the backup control section 108 by wire or wirelessly.
The battery control unit 104 is composed of a computer, and includes a processor 112, a memory unit 114, an input/output unit (I/O) 116, and a system communication unit 118. The processor 112 executes an OS (Operating System) and a battery control program stored in the memory unit 114. The memory unit 114 includes a ROM (Read-Only Memory) and a RAM (Random-Access Memory), and stores an OS and a battery control program. The system communication section 118 sends and receives control data to and from the remote controller control section 110, the system communication section 126 of the hot water supply unit control section 106, and the system communication section 134 of the backup control section 108. The temperatures detected by the temperature sensors 56 and 58 are input to the I/O 116 as control information, and the control output of the circulation pump 52 is obtained.

The hot water supply unit control section 106 is composed of a computer, and includes a processor 120, a memory section 122, an input/output section (I/O) 124, and a system communication section 126. The processor 120 executes the OS and hot water supply control program stored in the memory unit 122. The memory unit 122 includes a ROM, an electrically erasable programmable read-only memory (EEPROM), and a RAM, and stores an OS and a hot water supply control program. The system communication unit 126 sends and receives control data to and from the remote control control unit 110, the system communication unit 118 of the battery control unit 104, and the system communication unit 134 of the backup control unit 108. The temperatures detected by the temperature sensors 22, 66, 72, 76, and 78 and the amount of water detected by the water amount sensor 70 are input to the I/O 124 as control information, and control outputs from the heating pump 64 and the mixing valve 68 are obtained.
The backup control unit 108 is composed of a computer and includes a processor 128, a memory unit 130, an input/output unit (I/O) 132, and a system communication unit 134. The processor 128 executes the OS and backup control program stored in the memory unit 130. The memory unit 130 includes ROM, EEPROM, and RAM, and stores an OS and a backup control program. The system communication section 134 sends and receives control data to and from the remote control control section 110, the system communication section 118 of the battery control section 104, and the system communication section 126 of the hot water supply unit control section 106. The temperatures detected by the temperature sensors 84, 90, 92, and 100 and the amount of water detected by the water amount sensor 85 are input to the I/O 132 as control information, and the control outputs of the circulation pump 96, water control valve 86, and mixing valve 88 are obtained. It will be done.

<Hot water supply control using heat medium ME1>
6A shows the relationship between the water supply temperature and the minimum heating medium temperature when the hot water supply temperature setting (hereinafter referred to as "set temperature Ts1") is 35 [°C], and FIG. C in FIG. 6 shows the relationship between the feed water temperature and the minimum heat medium temperature when the set temperature Ts1 is 45 [° C.].
From these relationships, FIG. 7 shows a graph of the relationship between the supply water temperature and the lowest heat medium temperature using the set temperature Ts1 as a parameter. In FIG. 7, A is the case where the set temperature Ts1 = 35 [°C], B is the case where the set temperature Ts1 = 40 [°C], and C is the case where the set temperature Ts1 = 45 [°C].
From this relationship, for example, if the supply water temperature is 15 [°C] and the set temperature Ts1 is 40 [°C], the minimum heat medium temperature needs to be 60.6 [°C].

<When hot water can be supplied at the set temperature Ts1 using the heating medium ME1>
A in FIG. 8 shows the operation when the hot water supply unit 44 is capable of supplying hot water at the set temperature Ts1 using the heating medium ME1. In A of FIG. 8, thick lines indicate the flow of the supply water W, hot water HW, and heat medium ME1.
When it is possible to supply hot water at the set temperature Ts1 with the heating medium ME1, in the hot water supply unit 44, the detected temperature To1 (temperature after heat exchange) of the temperature sensor 76 is higher than the set temperature Ts1 by, for example, 6 [°C] (Ts1 + 6 [°C)]. ) (first target temperature for heat exchange). The opening degrees of ports a and b of the mixing valve 68 are controlled so that the temperature Tm1 detected by the temperature sensor 78 becomes the set temperature Ts1.

At this time, in the backup hot water supply unit 46, the temperature Ti2 detected by the temperature sensor 84 is equal to or higher than the set temperature Ts1, so the mixing valve 88 controls the opening degree of the port d side to 100%. Since the burner 102 does not cause combustion, water does not flow through the mixing valve 88 on the port c side. For example, when the set temperature Ts1 = 40 [°C] and the detected temperature Ti1 of the temperature sensor 72 = 20 [°C], the ratio of the flow rate on the port a side and the flow rate on the port b side of the mixing valve 68 is a:b=77 :23 is sufficient. In the mixing valve 88 of the backup hot water supply unit 46, the water amount on the port d side is 100%. In other words, when hot water can be supplied at the set temperature Ts1 using the heat medium ME1, 77% of the total amount of water flowing into the hot water supply system 2 flows to the heat exchanger 60, and 23% of the total amount of water flows to the bypass pipe 16. flows. As a result, 77% of the total amount of water is affected by the heat exchanger 60.

<When hot water cannot be supplied at the set temperature Ts1 using heating medium ME1>
B in FIG. 8 shows a hot water supply operation when the hot water supply unit 44 cannot supply hot water at the set temperature Ts1 using the heating medium ME1. In B of FIG. 8, thick lines indicate the flow of the supply water W, the hot water HW, and the heat medium ME1, ME2.
In this case, the rotation speed of the heating pump 64 is controlled so that the detected temperature To1=(T1-5 [° C.]). If the target temperature of the detected temperature Tm1 is the normal set temperature Ts1, the flow rate ratio of route a increases as the detected temperature To1 decreases, and the total water amount is ultimately affected by the heat exchanger 60. Therefore, the target temperature of the detected temperature Tm1 is set to the temperature at which mixing of route a and route b of the mixing valve 68 is performed. That is, the detected temperature Tm1 is changed from the set temperature Ts1 to the set temperature Ts2 (<Ts1). This set temperature Ts2 only needs to be lower than the set temperature Ts1. For example, if To1 is controlled to (T1-5 [°C]), firstly, the set temperature Ts2 = (Ti1 + (T1-5)). )/2 as the target temperature, the opening degree of the mixing valve 68 is adjusted to provide a flow rate of 50% to each port a and b. As a result, it is possible to reduce pressure loss due to the supply water W flowing to the a route side.

Second, if the target temperature is set closer to the detected temperature Ti1, such as set temperature Ts2=(Ti1+Ti1+(T1-5))/3, the flow rate flowing to route b of the mixing valve 68 can be increased. Therefore, the pressure loss of the water supply W flowing to the route a side can be further reduced.
In this way, there is no need to change the control form of the mixing valve 68 by simply changing the set temperature Ts1 to the set temperature Ts2. Therefore, there is no need to redesign the software.
In this case, on the backup hot water supply unit 46 side, the circulation pump 96 is driven, the burner 102 is fired, and the detected temperature Tj is controlled to be 80 [° C.]. Since the detected temperature Ti2 is lower than the set temperature Ts1, it is mixed with the detected temperature To2≈80 [° C.], and the opening degree of the mixing valve 88 is controlled so that the detected temperature Tm2 becomes the set temperature Ts1.
At this time, since the detected temperature Ti2 is closer to the set temperature Ts1 than the detected temperature To2, the flow rate on the port c side and the flow rate on the port d side of the mixing valve 88 are such that the flow rate on the port c side<the flow rate on the port d side.

For example, if the set temperature Ts1 = 40 [°C] and the detected temperature Ti1 = 20 [°C], then if the detected temperature T1 = 40 [°C], the detected temperature To1 = 35 [°C].
Here, the set temperature Ts2 is
(Ti1+T1-5)/2=(20+35)/2=27.5 [℃]
Therefore, if the target temperature of the detected temperature Tm1 is changed from the set temperature Ts1 to the set temperature Ts2, the a side flow rate and the b side flow rate of the mixing valve 68 become a side flow rate: b side flow rate = 50:50, and the detected temperature Tm1 =27.5 [°C].
Since the detected temperature Ti2 is 27.5 [°C], if the detected temperature To2 is mixed with hot water HW of 80 [°C] and the detected temperature Tm2 is controlled to 40 [°C], the flow rate on the port c side of the mixing valve 88, The flow rate on the port d side is the flow rate on the port c side: the flow rate on the port d side≈24:76. Therefore, 50% of the total amount of water is affected by the heat exchanger 60, and about 24% of the total amount of water is affected by the heat exchanger 80. This reduces pressure loss due to the heat exchangers 60, 80.

<When heat exchange by heat medium ME1 is not possible>
C in FIG. 8 shows the operation when heat exchange by the heat medium ME1 is not possible. In C of FIG. 8, thick lines indicate the flow of the water supply W and the heat medium ME2.
When heat exchange by the heat medium ME1 is not possible, the hot water supply unit 44 has low heat storage and cannot be used for heat exchange for hot water supply, so the mixing valve 68 is controlled to flow 100% of the water supply W to the port b side. , the heating pump 64 is in a stopped state. In this case, the detected temperature Tm1 becomes the detected temperature Ti1.

In the backup hot water supply unit 46, the circulation pump 96 is driven, the burner 102 is combusted, and the detected temperature Tj is controlled to be 80 [° C.].
Since the detected temperature Ti2 is less than the set temperature Ts1, the opening degree of the mixing valve 88 is controlled so that it is mixed with the hot water HW of the detected temperature To2≈80 [° C.] and the detected temperature Tm2 becomes the set temperature Ts1.
Since the detected temperature Ti2 is closer to the set temperature Ts1 than the detected temperature To2, the ratio of the flow rate on the port c side and the flow rate on the port d side of the mixing valve 88 is such that the flow rate on the port c side<the flow rate on the port d side.

For example, if the set temperature Ts1 = 40 [°C] and the detected temperature Ti1 = 20 [°C], then if the detected temperature T1 = 20 [°C], the heating pump 64 will be in a stopped state.
At this time, the ratio of the flow rate on the port a side and the flow rate on the port b side of the mixing valve 68 is the flow rate on the port a side: the flow rate on the port b side = 0:1. At this time, 100% of the total flow flows to the port b side.
Since the detected temperature Ti2 = Tm1 = Ti1 = 20 [°C], when mixing with the detected temperature To2≒80 [°C] and controlling the detected temperature Tm2 to the set temperature Ts1 = 40 [°C], the flow rate on the port c side of the mixing valve 88 , the ratio of the port d side flow rate is port c side flow rate:port d side flow rate≒1:2.
Therefore, 1/3 of the total amount of water is affected by the heat exchanger 80, and no pressure loss occurs due to the heat exchanger 60.

<Control of hot water supply system 2>
FIG. 9 shows a processing procedure for controlling the hot water supply system 2. As shown in FIG. This control includes each control of the remote control control section 110, battery control section 104, hot water supply unit control section 106, and backup control section 108, and each control is executed in conjunction with each other.
After initialization (S101), the remote control control unit 110 repeatedly executes input reception processing (S102) and display output processing (S103). In the display output process, status information obtained by the battery control section 104, hot water supply unit control section 106, or backup control section 108 is displayed on an LCD (Liquid Crystal Display).

After initialization (S104), the battery control unit 104 receives ON/OFF of the operation switch through the input reception process (S102), moves to the heat recovery process (S105) shown in FIG. 10, and changes the state obtained by this heat recovery process. The information is provided to the remote controller control unit 110.
After initialization (S106), the hot water supply unit control unit 106 receives an instruction for the set temperature Ts1 through the input reception process (S102), moves to the hot water supply process (S107) shown in FIG. 11, and uses the status information obtained in this hot water supply process. The information is provided to the remote control control unit 110.
After initialization (S108), the backup control unit 108 receives an instruction for the set temperature Ts1 through an input reception process (S102), moves to a backup hot water supply process (S109) shown in FIG. is provided to the remote controller control unit 110.

<Heat recovery treatment>
FIG. 10 shows a procedure for heat recovery processing by the battery control unit 104. In this processing procedure, the operation of the operation switch in the input reception process (S102) of the remote control control unit 110 is monitored (S201), and if the operation switch is ON (YES in S201), the fuel cell 48 is driven (S202), The rotation of the circulation pump 52 is controlled so that the output temperature of the temperature sensor 58 is, for example, 75 [° C.] (S203).
If the operation switch is OFF (NO in S201), the fuel cell 48 is stopped (S204), and the circulation pump 52 is stopped (S205).

<Hot water supply process>
FIG. 11 shows a procedure for hot water supply processing by the hot water supply unit 44. In this processing procedure, it is determined whether hot water supply is being used (S301), and if hot water supply is not being used (NO in S301), the heating pump 64 is stopped (S302), and this processing is ended.
If hot water is being used (YES in S301), it is determined whether the detected temperature T1 is equal to or higher than the temperature at which the set temperature Ts1 can be supplied (S303). If the detected temperature T1 is equal to or higher than the temperature at which the set temperature Ts1 can be supplied (S303: YES), the hot water supply process shown in A of FIG. 8 is executed (S304). In this process, the rotation of the heating pump 64 is controlled so that the detected temperature To1 becomes a constant temperature ΔT1 higher than the set temperature Ts1 by, for example, 6 [°C] (= set temperature Ts1 + ΔT1) (S305), and at the same time the detected temperature The opening degree of the mixing valve 68 is controlled so that Tm1 becomes the set temperature Ts1 (S306).

If the detected temperature T1 is not higher than the temperature at which the set temperature Ts1 can be supplied (NO in S303), the detected temperature T1 exceeds the temperature (=supply water temperature + ΔT2) higher by a constant temperature ΔT2 than the supply water temperature, for example, by 5 [°C]. (S307). If the detected temperature T1 exceeds the temperature (=water supply temperature +ΔT2) (YES in S307), the hot water supply process shown in B in FIG. 8 is executed (S308).
In this process, the rotation of the heating pump 64 is controlled so that the detected temperature To1 is a constant temperature ΔT2 lower than the detected temperature T1 by, for example, 5 degrees Celsius (=T1 temperature - ΔT2) (S309), and at the same time A target temperature of temperature Tm1 is calculated (S310).
In this process, the target temperature is calculated from the detected temperature To1 (=T1-ΔT2) and the detected temperature Ti1 of the water supply W. For example, the first target temperature may be (To1+Ti1)/2, or the second target temperature may be (To1+Ti1+Ti1)/3.
Then, the mixing valve 68 is controlled so that one of these target temperatures is obtained (S311).

In S307, if the detected temperature T1 is lower than the temperature (=supply water temperature +ΔT) (NO in S307), the process shown in C in FIG. 8 is executed (S312). In this process, the heating pump 64 is stopped (S313), and the mixing valve 68 is controlled so that 100% of water is supplied to port b (S314).

<Backup hot water processing>
FIG. 12 shows the processing procedure of the backup hot water supply process. In this processing procedure, it is determined whether or not hot water supply is used (S801). This determination may be made based on the amount of water detected by the water amount sensor 85.
If hot water supply is not being used (NO in S801), the hot water supply operation is stopped (S802), and this backup hot water supply process is ended.
If hot water is being used (YES in S801), it is determined whether the detected temperature Ti2 is lower than the set temperature Ts1 (S803). If the detected temperature Ti2 is lower than the set temperature Ts1 (YES in S803), the process shifts to feed water heating, and the circulation pump 96 is operated at a rotation speed corresponding to the required amount of heat (S804). At this time, the combustion of the burner 102 is controlled so that the detected temperature Tj becomes a predetermined temperature, for example, 80 [° C.] (S805). At the same time, the opening ratio of the mixing valve 88 is controlled so that the detected temperature Tm2 becomes the set temperature Ts1 (S806).
If the detected temperature Ti2 is equal to or higher than the set temperature Ts1 (NO in S803), the heating operation is stopped and the opening ratio of the mixing valve 88 is controlled so that the amount of water reaches 100% on the port d side.

<Relationship between heat exchanger side flow rate ratio and pressure loss>
FIG. 13 shows the relationship between the pressure loss and the flow rate ratio on the heat exchanger 60 side. This pressure loss relationship is based on a case where the total flow rate is 16 [liters/min]. According to this relationship, as the flow rate increases, the pressure loss also increases in a quadratic manner. Note that even at a flow rate of 0%, there is a pressure loss because the measurement is performed between the water supply inlet and the hot water supply inlet of the hot water supply unit 44, so the pressure loss on the common path and bypass pipe 16 side is It's for a reason.
Although such a relationship is a characteristic of the heat exchanger 60, the same tendency will occur in the heat exchanger 80 on the backup hot water supply unit 46 side if it has the same specifications as the heat exchanger 60.

<Effects of Example 1>
According to this first embodiment, the following effects can be obtained.
(1) Depending on the heat stored in the heat storage tank 8, the amount of heat can be used for hot water supply.
(2) When heat storage is low and cannot be used for hot water supply, the water supply W passed through the hot water supply unit 44 is heated to the set temperature Ts1 by the backup hot water supply unit 46, and hot water can be supplied at the set temperature Ts1.
(3) In heat storage, where the temperature of the water supply W cannot be raised to the set temperature Ts1, but a certain amount of heat exchange is possible, the amount of water supplied to the heat exchanger 60 is suppressed, reducing pressure loss and rotating the heating pump 64. It is possible to suppress the number of heat storages and achieve efficient use of heat storage.

(4) When the heat storage is low, forced circulation of the heat medium can be avoided and the stratification state of the heat storage tank 8 will not be disturbed.
(5) The opening ratio and flow rate ratio of the mixing valve 68 are generally not in a proportional relationship. This is because it becomes difficult to flow on the port side where pressure loss is high. This is because when the flow rate is small in the opening degree control, it is assumed that the flow rate ratio on the heat exchanger 60 side decreases. In other words, assuming such a phenomenon, the utilization rate of heat storage in the heat storage tank 8 will decrease, but with such control, the flow rate flowing to the heat exchanger 60 side is compensated, and the heat storage can be used effectively.

FIG. 14 shows a hot water supply system according to the second embodiment. In Example 1, the heat storage tank 8 was installed in the hot water supply unit 44, but as shown in FIG. 14 , the heat storage tank 8 was removed from the hot water supply unit 44, and the tank unit 43 provided with the heat storage tank 8 and the heat storage tank 8 were removed Similar control is possible even if the hot water supply unit 45 is used.

FIG. 15 shows a hot water supply system according to the third embodiment. In the second embodiment, the hot water supply unit 45 and the backup hot water supply unit 46 are configured separately, but as shown in FIG. It is possible.

In the above embodiment, the hot water supply unit 44 and the backup hot water supply unit 46 are configured independently, but the hot water supply unit 44, the backup hot water supply unit 46, and each control section may be configured as an integrated water heater.

[Other embodiments]
(1) In the above embodiment, the configuration in which the water amount adjustment section 12 is provided with the mixing valve M1 and the configuration in which the water amount adjustment section 38 is provided with the mixing valve M2 is exemplified, but the bypass pipe 16 is provided with a proportional valve to control the flow rate. May be adjusted.
(2) Although the fuel cell 48 is illustrated as the heat source of the heat medium ME1, it may be an exhaust heat source such as an engine.
(3) Although the burner 102 is used as the heat source for the heat medium ME2, other heat sources such as electric heat may be used.
(4) The memory units 122 and 130 may include storage units that individually store the set temperatures Ts1 and Ts2.
(5) In the above embodiment, when the set temperature Ts1 is switched to the set temperature Ts2, hot water HW at the set temperature Ts1 is discharged from the auxiliary heating section 6, but the present invention is not limited to this. Hot water HW having a temperature higher or lower than the set temperature Ts1 may be discharged from the auxiliary heating section 6.
(6) Regarding the control of the hot water temperature, the hot water temperature may be controlled to the set temperature Ts1 using the temperature detected by the temperature sensor 24, or the hot water temperature may be controlled to the set temperature Ts1 using the temperature detected by the temperature sensor 92. It's okay. In the latter case, when the piping from the hot water supply units 44, 45 to the backup hot water supply unit 46 is long, the temperature drop of the hot water HW from the hot water supply units 44, 45 can be backed up by auxiliary heating of the backup hot water supply unit 46.

As described above, the most preferred embodiment of the present invention has been described. The present invention is not limited to the above description. Various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the detailed description. It goes without saying that such modifications and changes are included within the scope of the present invention.

According to the present invention, waste heat and the like are stored in a heat medium, and hot water supply control is performed according to the heat storage of the heat medium, and in this hot water supply control, the amount of water flowing to the heat exchanger is controlled according to the heat storage, and the heat storage is By reducing the amount of water flowing into the heat exchanger when the water is low, pressure loss and power loss due to circulation can be reduced, and excellent effects such as not disturbing the stratified heat storage in the heat storage tank can be obtained, which is beneficial. It is.

2 Hot water supply system 4 Hot water supply section 6 Auxiliary heating section 8 Heat storage tank
9 pump
10 Heat exchanger 12 Water amount adjustment section
13 circulation route
14 Water supply pipe 16 Bypass pipe 18 Hot water outlet pipe 20 Control unit 22 Temperature sensor 24 Temperature sensor 26, 28 Heat exchanger 30 Water supply pipe 32 Temperature sensor 34 Heat source 36 Bypass pipe 38 Water amount adjustment unit 40 Hot water outlet pipe 42 Fuel cell unit
43 tank unit
44, 45, 47 Hot water supply unit 46 Backup hot water supply unit 48 Fuel cell 50 Heat exchanger 52 Circulation pump 54 Circulation path 56, 58 Temperature sensor 60 Plate heat exchanger 62 Circulation path 64 Heat pump 66 Temperature sensor 68 Mixing valve 70 Water amount sensor 72 Temperature sensor 74 Water control valve 76, 78 Temperature sensor 80 Plate heat exchanger 82 Heat exchanger 84 Temperature sensor 85 Water amount sensor 86 Water control valve 88 Mixing valve 90, 92 Temperature sensor 94 Circulation path 96 Circulation pump 98 Open tank 100 Temperature Sensor 102 Burner 104 Battery control section 106 Hot water supply unit control section 108 Backup control section 110 Remote control control section 112, 120, 128 Processor 114, 122, 130 Memory section 116, 124, 132 Input/output section (I/O)
118, 126, 134 System communication department

Claims (5)

a process of exchanging heat generated by power generation with a heat medium and storing the heat medium in a heat storage tank;
a step of circulating a heat medium from the heat storage tank to a heat exchanger and exchanging heat of the heat medium and water supply;
When the heat medium of the heat storage tank can exchange heat with the feed water, the feed water before heat exchange is passed through the heat exchanger and the bypass path, and the heat exchanger is exchanged with the feed water distributed to the bypass path. a step of mixing the heated water with
A first set temperature and a second set temperature that is lower than the first set temperature by a predetermined temperature are set, and whether hot water can be tapped at the first set temperature is determined based on the temperature of the heating medium, and hot water can be tapped. If so, the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed and hot water is discharged at the first set temperature, and if hot water cannot be discharged, the second set temperature is set. , the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed, heated to the second set temperature, flowed to the auxiliary heating section, and heated in the auxiliary heating section. a step of supplying hot water at the first set temperature and reducing the amount of water supplied to the heat exchanger to reduce pressure loss in the heat exchanger;
hot water supply methods, including Further, when hot water is tapped at the second set temperature, the amount of water supplied to the bypass path is increased from the amount of water supplied to the heat exchanger;
The hot water supply method according to claim 1, comprising: A heat storage tank that stores a heat medium with which heat generated during power generation is exchanged;
a heat exchanger that circulates a heat medium from the heat storage tank and exchanges heat between the heat of the heat medium and the water supply;
When the heat medium of the heat storage tank can exchange heat with the feed water, the feed water before heat exchange is passed through the heat exchanger and the bypass path, and the heat exchanger is exchanged with the feed water distributed to the bypass path. mixing means for mixing the hot water;
A first set temperature and a second set temperature that is lower than the first set temperature by a predetermined temperature are set, and whether hot water can be tapped at the first set temperature is determined based on the temperature of the heating medium, and hot water can be tapped. If so, the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed and hot water is discharged at the first set temperature, and if hot water cannot be discharged, the second set temperature is set. , the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed, heated to the second set temperature, flowed to the auxiliary heating section, and heated in the auxiliary heating section. a control unit that discharges hot water at the first set temperature and reduces the distribution amount of the feed water flowing to the heat exchanger to reduce pressure loss of the heat exchanger;
Including hot water system. A program to be executed by a computer,
A function to obtain temperature information of the heat medium circulated from the heat storage tank to the heat exchanger,
A function of controlling the opening degree on the heat exchanger side and the opening degree on the bypass path side of a mixing valve that causes the feed water to flow through the heat exchanger and the bypass path;
When the heat medium of the heat storage tank can exchange heat with the water supply, a first set temperature and a second set temperature lower than the first set temperature by a predetermined temperature are set, and the first set temperature is lower than the first set temperature. It is determined whether hot water can be tapped based on the temperature of the heating medium, and if hot water can be tapped, the supplied water distributed to the bypass path and the hot water obtained by the heat exchanger are mixed and the first The hot water is discharged at the set temperature, and if hot water cannot be discharged, the temperature is switched to the second set temperature, and the supplied water distributed to the bypass path and the hot water obtained by the heat exchanger are mixed to achieve the second setting. heating the water to a temperature and flowing it to an auxiliary heating section, heating it at the auxiliary heating section and discharging it at the first set temperature, reducing the distribution amount of the feed water flowing to the heat exchanger, and reducing the pressure of the heat exchanger. A function to reduce loss,
A program for causing the computer to execute. a heat exchanger that circulates the heat medium from a heat storage tank that stores the heat medium with which the heat generated during power generation has been exchanged, and exchanges the heat with the water supply;
When the heat medium of the heat storage tank can exchange heat with the feed water, the feed water before heat exchange is passed through the heat exchanger and the bypass path, and the heat exchanger is exchanged with the feed water distributed to the bypass path. mixing means for mixing the hot water;
A first set temperature and a second set temperature that is lower than the first set temperature by a predetermined temperature are set, and whether hot water can be tapped at the first set temperature is determined based on the temperature of the heating medium, and hot water can be tapped. If so, the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed and hot water is discharged at the first set temperature, and if hot water cannot be discharged, the second set temperature is set. , the water supply distributed to the bypass path and the hot water obtained by the heat exchanger are mixed, heated to the second set temperature, flowed to the auxiliary heating section, and heated in the auxiliary heating section. a control unit that discharges hot water at the first set temperature and reduces the distribution amount of the feed water flowing to the heat exchanger to reduce pressure loss of the heat exchanger;
including water heaters.

Images