JP7220487B2 - Systems, methods and units of hot water supply - Google Patents

Description

The present invention relates to, for example, a hot water supply technology that utilizes thermal energy generated in a fuel cell to heat hot water.

2. Description of the Related Art There is known a hot water supply system that uses thermal energy, such as thermal energy generated by an engine generator using gas or the like as a fuel or a fuel cell, or solar heat, to heat hot water.
In such a hot water supply system, auxiliary heating is performed when the amount of heat stored is insufficient for the amount of heat required for hot water supply. When gas combustion heat is used as an auxiliary heat source, the required water supply is used to guarantee the lower limit of the combustion heat.
In such a hot water supply system, if the hot water temperature in the hot water storage tank is lower than the set temperature at the start of hot water supply, the temperature of the auxiliary heat source is adjusted to a low level that does not exceed the lower limit capacity of the auxiliary heat source from the start of hot water supply to the stop of hot water supply. It is known to perform additional heating by (Patent Document 1). Regarding the efficient use of the auxiliary heat source, it is known to operate the auxiliary heat source during hot water supply to reduce heat radiation to the atmosphere and fuel consumption compared to keeping hot water in the hot water storage tank ( For example, Patent Document 2).

JP 2003-148804 A JP 2007-311036 A

By the way, regarding the mode of use of the auxiliary heat source, when the unused state is changed to the used state, the amount of water supply mixed with hot water is increased in order to guarantee the lower limit capacity. In other words, increasing the amount of water supply means that the heat utilization from the heat storage tank is reduced accordingly. Such a state may result in insufficient utilization of the heat storage amount and cause fluctuations in the hot water supply temperature.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such problems by increasing the utilization rate of the amount of heat stored by a heat medium that is heated by exchanging heat with the exhaust heat of a fuel cell, and stabilizing the supply of hot water. .

In order to achieve the above object, according to the hot water supply system of the present invention, a hot water supply unit for generating hot water from supplied water, and an auxiliary heat source for heating the hot water when the hot water generated by the hot water supply unit is lower than a set temperature. A hot water supply system used in combination, wherein a heat storage tank for storing heat by storing a first heat medium and heat exchange between the first heat medium taken out from the upper layer of the heat storage tank and water supply, and the first heat medium and a second heat exchange means for supplying hot water at a set temperature by heat exchange between the second heat medium heated by the combustion heat of the combustion means and the hot water. a temperature sensor for correlating the time to complete the start-up of combustion of the combustion means with the volumetric position of the heat storage tank, and detecting the temperature of the first heat medium at the volumetric position; a control unit that controls the circulation amount of the first heat medium using the detected temperature of the heat medium.
In order to achieve the above object, according to the hot water supply method of the present invention, a hot water supply unit for generating hot water from supplied water and an auxiliary heat source for heating the hot water when the hot water generated by the hot water supply unit is lower than a set temperature are provided. A hot water supply method used in combination, wherein a heat storage tank stores and stores heat with a first heat medium; and a step of controlling the circulation amount of the first heat medium; and a second heat exchange means exchanging heat between the second heat medium heated by the combustion heat of the combustion means and the hot water. a step of discharging hot water at a set temperature by means of a temperature sensor, relating a time to complete combustion start-up of the combustion means and a volume position of the heat storage tank, and determining the temperature of the first heat medium at the volume position; and a step of the controller controlling at least the circulation amount of the first heat medium using the detected temperature of the first heat medium.

In order to achieve the above object, according to the hot water supply unit of the present invention, a hot water supply unit for generating hot water from water supply and an auxiliary heat source for heating the hot water when the hot water generated by the hot water supply unit is lower than a set temperature. A hot water supply unit used in a hot water supply system used in combination, wherein heat is exchanged between a heat storage tank that stores and stores a first heat medium, and the first heat medium taken out from the upper layer of the heat storage tank and water supply, A first heat exchange means for controlling the circulation amount of the first heat medium, and a second heat medium heated by the combustion heat of the combustion means and the hot water for supplying hot water at a set temperature by heat exchange between the hot water and the second heat medium. 2, a heat exchange means, a temperature sensor for correlating the time to complete the start-up of combustion of the combustion means and the volume position of the heat storage tank, and detecting the temperature of the first heat medium at the volume position; and a control unit for controlling the circulation amount of the first heat medium using the detected temperature of the first heat medium.

ADVANTAGE OF THE INVENTION According to this invention, one of the following effects is acquired.
(1) Effective use of stored heat can be achieved by associating the detection position of the heat storage temperature of the heat medium tank with the capacity of the auxiliary heat source of hot water.
(2) Exhaust heat from the fuel cell can be stored and effectively used for hot water heating, and efficient use of exhaust heat can be achieved.
(3) Fluctuations in hot water supply temperature can be suppressed, and hot water supply can be stabilized.
(4) Hot water supply capacity can be improved.

1 is a diagram showing a hot water supply system according to an embodiment; FIG. 4 is a flowchart showing hot water supply control of a hot water supply unit 4-1. 4 is a flowchart showing hot water supply control of a hot water supply unit 4-2. It is a figure which shows the operation pattern in case of T4>=T. FIG. 10 is a diagram showing an operation pattern when T1<(T+β); It is a figure which shows the operation pattern in case of T4<T. FIG. 4 is a diagram showing operation timing; 1 is a diagram showing a cogeneration system according to Example 1; FIG. It is a figure which shows the position of the temperature sensor of a heat-medium tank. It is a figure which shows a control part. 4 is a flowchart showing cooperative control; 4 is a flow chart showing control of the fuel cell unit; 4 is a flowchart showing hot water supply control of a hot water supply unit 4-1. 4 is a flowchart showing hot water supply control of a hot water supply unit 4-1. 4 is a flowchart showing hot water supply control of a hot water supply unit 4-2. 4 is a flowchart showing hot water supply control of a hot water supply unit 4-2. 4 is a flow chart showing a sequence of communication control; FIG. 11 is a diagram for explaining control according to the second embodiment; FIG. FIG. 10 is a diagram showing a fuel cell and a hot water supply unit according to Example 3; FIG. 10 is a diagram showing a hot water supply apparatus according to Embodiment 4;

FIG. 1 shows a hot water supply system according to one embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to the configuration.
The hot water supply system 2 includes a first hot water supply unit 4-1 and a second hot water supply unit 4-2. The hot water supply unit 4-1 has a heat storage function and a hot water supply function. The hot water supply unit 4-1 is provided with a heat medium tank 6 in which the first heat medium HM1 is stored. , the high-temperature heat medium HM1 heated by circulating through the exhaust heat source is returned to the upper layer of the heat medium tank 6 . As a result, heat storage is performed in a hierarchical state. For example, an open heat storage tank is used as the heat medium tank 6 . The heat medium HM<b>1 is a heat medium for cooling on the exhaust heat source side, recovers heat from the exhaust heat source, and stores the heat in the heat medium tank 6 . The heat medium tank 6 is provided with a plurality of temperature sensors for detecting the temperatures of the upper, middle and lower heat medium, and the detected temperature T1 of the third temperature sensor 10-1 represents the temperature of the upper heat medium. Due to this heat storage function, in the hot water supply function, the heat of the heat medium HM1 is heat-exchanged with the water supply W, and the hot water HW is supplied.

During hot water supply, the water supply W supplied to the water supply path 8-2 flows into the heat exchanger 12-1. At this time, by driving the circulation pump 14-1, the heat medium HM1 flows from the upper layer side of the heat medium tank 6 through the heat medium circulation path 8-3 to the heat exchanger 12-1. The heat exchanger 12-1 is an example of a first heat exchange section. In the heat exchanger 12-1, the heat of the heat medium HM1 is heat-exchanged with the feed water W, and the heat of the heat medium HM1 produces hot water HW from the feed water W. This hot water HW is supplied from the first hot water supply passage 8-4.

In this hot water supply unit 4-1, if the set temperature of the hot water HW is T, heat exchange between the water supply W and the heat medium HM1 is performed at a temperature (T+α ), heat exchange is performed. A temperature T2 of the feed water W is detected by a first temperature sensor 10-2 installed on the inlet side of the water supply passage 8-2. A temperature T3 of the hot water HW on the outlet side is detected by the second temperature sensor 10-3. The hot water HW in the hot water supply path 8-4 flows to the mixing valve 16-1, which is an example of mixing means, in the hot water supply path 8-4. This mixing valve 16-1 is connected to a bypass 8-5 on the side of the water supply line 8-2, and the opening ratio of the hot water supply line 8-4 side and the bypass line 8-5 side of the mixing valve 16-1 is It is possible to mix the feed water W with the hot water HW in a corresponding mixing ratio. Therefore, if the amount of heat of the heat medium HM1 in the heat medium tank 6 is equal to or greater than the amount of heat necessary to obtain the hot water HW at the set temperature T, the hot water HW at the set temperature T can be obtained by using only the hot water HW or the mixed water of the hot water HW and the feed water W. However, the outlet temperature of the hot water HW will be lower than the set temperature T if the amount of heat is insufficient.

The hot water supply path 8-4 of the hot water supply unit 4-1 is connected to the hot water supply path 8-6 of the hot water supply unit 4-2, and the hot water supply path 8-6 constitutes a continuous water supply path with the hot water supply path 8-4. As a result, hot water HW discharged from hot water supply unit 4-1 is supplied to hot water supply path 8-6 of hot water supply unit 4-2. If the temperature of the hot water HW flowing through the hot water supply path 8-6 is the set temperature T, the hot water supply unit 4-2 does not need to be heated, and the hot water can be directly discharged from the hot water supply unit 4-2. That is, hot water can be discharged through the second mixing valve 16-2 from the bypass 8-7 branching from the hot water supply passage 8-6. The mixing valve 16-2 is an example of hot water switching means.

When the temperature T1 detected by the temperature sensor 10-1 for detecting the upper layer temperature of the heat medium tank 6 falls below the temperature (T+β) higher than the set temperature T by β (β>α) degrees {T1<(T+β)} , predicts a heat shortage and operates the auxiliary heat source 18 . The auxiliary heat source 18 uses, for example, a burner 19 for burning fuel gas as a heat source. In this case, the auxiliary heat amount is combustion heat, but may be electric heat or solar heat. When the auxiliary heat source 18 is operated, the circulation pump 14-2 is operated to circulate the second heat medium HM2 in the heat medium circulation path 8-8, and the combustion heat of the burner 19 is an example of the third heat exchange section. is heat-exchanged to the heat medium HM2 by the heat exchanger 12-3. At this time, the combustion heat amount of the burner 19 is adjusted so that the heat medium HM2 after heat exchange reaches a predetermined temperature (for example, 80 [° C.]). As a result, the heat medium HM2 is heated by the burner 19 to compensate for the shortage of the heat amount of the heat medium HM1.

When the temperature T4 detected by the temperature sensor 10-4 is below the set temperature T (T4<T), the hot water HW is supplied from the hot water supply passage 8-6 to the heat exchanger 12-2, which is an example of the second heat exchange unit. is introduced to perform heat exchange between the heat medium HM2 and the hot water HW. The hot water HW is thereby heated. A temperature sensor 10-5 detects the temperature T5 of the hot water HW on the outlet side of the heat exchanger 12-2. Hot water HW after heat exchange in the heat exchanger 12-2 flows to the mixing valve 16-2. A bypass 8-7 on the side of the hot water supply path 8-6 communicates with the mixing valve 16-2. It is possible to mix the hot water HW before heat exchange with the hot water HW after heat exchange at the mixed ratio. If the temperature T5 of the hot water HW after heat exchange is higher than the set temperature T, the hot water HW before heat exchange and the hot water hHW after heat exchange are mixed from the bypass passage 8-7 at a mixing ratio corresponding to the opening ratio, Mixed water mHW (=HW+hHW) at a set temperature T is discharged. The temperature of this mixed water mHW is detected by the temperature sensor 10-6 in the hot water supply passage 8-6, and this detected temperature T6 is used to adjust the opening of the mixing valve 16-2 that adjusts the mixed water mHW to the set temperature T. .

<Control of hot water supply units 4-1 and 4-2>
Control during hot water supply is as follows.
(1) The heat of the heat medium HM1 is heat-exchanged with the feed water W to generate hot water HW having a temperature higher than the set temperature T by α degrees, and the outlet temperature of the hot water HW is controlled to the set temperature T by the mixing valve 16-1.
(2) If T1<(T+β), start the operation of the auxiliary heat source 18 of the hot water supply unit 4-2.
(3) If the temperature of the hot water HW supplied from the hot water supply unit 4-1 to the hot water supply unit 4-2 is the set temperature T, the hot water HW is discharged from the bypass 8-7 through the mixing valve 16-2.
(4) When T4<T, the mixed water mHW at the set temperature T is discharged by adjusting the opening ratio of the mixing valve 16-2 by exchanging the heat of the heating medium HM2 with the hot water HW.

<Hot water supply control of hot water supply unit 4-1>
FIG. 2 shows a processing procedure of hot water supply control of the hot water supply unit 4-1. When the hot water supply unit 4-1 starts operating, it is determined whether or not hot water supply is in use (S11). If hot water supply is not used (NO in S11), circulation pump 14-1 is stopped (S12), and this hot water supply process ends. If hot water supply is used (YES in S11), it is determined whether the detected temperature T1 of the upper layer of the heat medium tank 6 exceeds the detected temperature T2 of the feed water W (T1>T2) (S13). If T1>T2 (YES in S13), the rotation speed of the circulation pump 14-1 is controlled so that the detected temperature T3 of the hot water HW on the outlet side of the heat exchanger 12-1 becomes the temperature (T+α) (S14 ), and if T1>T2, that is, if T2≧T1 (NO in S13), the circulation pump 14-1 is stopped (S15).

Through S14 or S15, it is determined whether the detected temperature T1 is T1<(T+β) (S16). If T1<(T+β) (YES in S16), it is determined that there is no heat storage in the heat medium tank 6 (S17). ), it is determined that heat is stored in the heat medium tank 6 (S18).
Then, the mixture ratio of the hot water HW and the water supply W is adjusted by the opening degree ratio of the mixing valve 16-1, and the hot water HW to be discharged is controlled to the set temperature T (S19).

<Hot water supply control of hot water supply unit 4-2>
FIG. 3 shows the hot water supply control processing procedure of the hot water supply unit 4-2. It is determined whether or not the hot water supply unit 4-2 is also used for hot water supply (S21). If the hot water supply is not used (NO in S21), the circulation of the heating medium HM2 is stopped by stopping the circulation pump 14-2 (S22), and this hot water supply process ends. If hot water is to be supplied (YES in S21), it is determined whether or not heat is stored in the heat medium tank 6 of the hot water supply unit 4-1 (S23).

If no heat is stored (YES in S23), circulation of the heat medium HM2 is started to operate the auxiliary heat source 18 (S24). If no heat is stored (NO in S23), it is determined whether the detected temperature T4 of the hot water HW flowing from the hot water supply unit 4-1 to the hot water supply unit 4-2 is less than the set temperature T (T4<T) (S25). . If T4<T (YES in S25), circulation of the heat medium HM2 is started (S24). If T4<T, that is, if T4≧T (NO in S25), circulation of the heat medium HM2 is started. Stop and stop the auxiliary heat source 18 (S26).

After starting circulation of the heat medium HM2 (S24), it is determined whether the detected temperature T4 of the hot water HW is less than the set temperature T (T4<T) (S27). If T4<T (YES in S27), the hot water HW flowing from the hot water supply unit 4-1 to the hot water supply unit 4-2 is heated by the heat exchanger 12-2 by changing the opening ratio of the mixing valve 16-2. By using the replaced hot water hHW, the temperature of the discharged hot water HW is controlled to the set temperature T (S28). In this case, mixed water mHW (=HW+hHW) of hot water hHW after heat exchange and hot water HW before heat exchange is discharged.
If not T4<T, that is, if the detected temperature T4 is the set temperature T (NO in S27), the opening of the mixing valve 16-2 is switched to the side of the bypass 8-7, and hot water is supplied from the hot water supply unit 4-1. The hot water HW flowing into the unit 4-2, that is, the hot water HW before heat exchange flowing to the bypass 6-7 side is discharged (S29).

<Operation pattern>
When T4≧T, the amount of heat stored in the heat medium tank 6 is sufficient to discharge hot water at the set temperature T. Therefore, as shown in FIG. The hot water HW controlled to T is discharged from the bypass 8-7 through the mixing valve 16-2.
In this way, when hot water is started at T4≧T, and T1<(T+β) occurs during the hot water tapping, as shown in FIG. Circulate through the circulation path 8-8.

In the case of T4<T, the amount of heat stored in the heat medium tank 6 is insufficient to discharge hot water at the set temperature T, so the heat of the heat medium HM2 heated by the auxiliary heat source 18 is heat-exchanged with the hot water HW, and hot water is produced. Auxiliary heating of HW is performed. As shown in FIG. 6, when T4<T while the hot water HW is being discharged (FIG. 4), the bypass passage 8-5 of the mixing valve 16-1 is closed and the hot water supply passage 8-4 side is opened. and As a result, only the hot water HW passes through the mixing valve 16-1. At this time, the temperature sensor 10-4 detects the temperature of the hot water HW.

The heat of the heat medium HM2 is heat-exchanged with the hot water HW, and the hot water hHW is obtained from the heat exchanger 12-2. The mixing valve 16-2 mixes the hot water HW before heat exchange from the bypass 8-7 with the hot water hHW after heat exchange in the heat exchanger 12-2 to obtain mixed water mHW. The outlet temperature of the mixed water mHW is detected by the temperature sensor 10-6, and the ratio of the degree of opening of the mixing valve 16-2 on the side of the bypass passage 8-7 and the degree of opening on the side of the hot water hHW is controlled. Thus, the mixed water mHW controlled to be discharged is obtained.

A, B, C, D, E and F in FIG. 7 indicate operation timings of hot water supply control.
A in FIG. 7 shows the temperature drop of the heat medium HM1 in the heat medium tank 6. FIG. T is the set temperature of the hot water HW, T1 is the change in temperature detected by the temperature sensor 10-1, T4 is the change in temperature detected by the temperature sensor 10-4, and Tx is the change in temperature of the hot water HW entering the mixing valve 16-1. showing. Thus, the temperature (T4) of the hot water HW is controlled to the set temperature T even if the temperature (T1) of the heat medium HM1 changes. The reason why the temperature Tx is higher than the detected temperature T1 is that the hot water HW heat-exchanged with the high-temperature heat medium HM1 flows from the upper layer side of the heat medium tank 6 to the mixing valve 16-1. This temperature is detected by the temperature sensor 10-3.
At time t1 when T1≧T+β changes to T1<T+β, the operation of the auxiliary heat source 18 is started. If the auxiliary heat source 18 is a burner, combustion starts at time t1. That is, the auxiliary heat source 18 is operated in advance before the temperature T4 detected by the temperature sensor 10-4 drops. As a result, as shown in FIG. 7B, the heat medium temperature Tm is increased by the heat of the burner 19 from the operation start time t1 of the auxiliary heat source 18, and is maintained at a constant temperature.

At time t2 when the detected temperature T4 falls below the set temperature T, the control area C1 of the mixing valve 16-1 is switched to the control area C2 of the mixing valve 16-2, as shown in FIG. 7C. There is a time Δt between time t1 and time t2. In other words, this means that the operation of the auxiliary heat source 18 precedes the time t2 by the time Δt. As a result, the operation of the auxiliary heat source 18 is started before switching to the control region C2 of the mixing valve 16-2, and the heat medium temperature Tm is maintained at a constant temperature.

D in FIG. 7 shows a case where the heat storage temperature of the heat medium tank 6 rises during the tapping of mixed water mHW. T is the set temperature of the outlet hot water, T1 is the temperature detected by the temperature sensor 10-1 (=heat medium temperature), T4 is the temperature detected by the temperature sensor 10-4 (= outlet hot water temperature), and Tx is the hot water entering the mixing valve 16-1. An example of HW temperature transition is shown. Time t3 is when the detected temperature T4 rises above the set temperature T, and time t4 is when the detected temperature T1 exceeds the set temperature T+β, which is when the auxiliary heat source 18 stops operating.

As shown in E of FIG. 7, the heat medium temperature Tm is maintained at a constant temperature by heating by the burner 19 in the auxiliary heat source 18, and at time t4, the operation of the auxiliary heat source 18 is stopped and the heat medium temperature Tm gradually decreases.
Then, as shown in FIG. 7F, at time t3 when T4<T changes to T4≧T, the control area C2 of the mixing valve 16-2 is switched to the control area C1 of the mixing valve 16-1. As a result, the hot water HW and the feed water W are mixed or the hot water at the set temperature T is discharged only with the hot water HW.

<Effect of one embodiment>
According to this embodiment, the following effects are obtained.
(1) When T4≧T, hot water is supplied at the set temperature T using hot water HW and feed water W obtained on the hot water supply unit 4-1 side. Since hot water supply at the set temperature T is realized without operating the auxiliary heat source 18, it is economical.
(2) When T4<T, the heat of the heating medium HM2 heated by the auxiliary heat source 18 is heat-exchanged to the hot water HW together with the hot water HW on the hot water supply unit 4-1 side. hot water HW is used entirely, the utilization rate of the heat storage amount of the heat medium HM1 in the heat medium tank 6 is high, and hot water can be supplied efficiently.
(3) When T1≧T+β changes to T1<T+β during hot water supply, the auxiliary heat source 18 is operated in advance at that time, and the heat of the heat medium HM2 can be quickly exchanged with the hot water HW. Therefore, undershoot due to insufficient heat storage in the heat medium tank 6 can be suppressed, and hot water at the set temperature T can be stably supplied.
(4) When the detected temperature T1 of the upper layer of the heat medium tank 6 is equal to or higher than the predetermined set temperature T+β, the hot water of the set temperature T is supplied, and when it is lower than the set temperature T, the hot water is supplied with the hot water HW of the same temperature and supplemented. The heat source 18 can be controlled to the set temperature T regardless of the temperature difference between the set temperature T and the hot water HW.

FIG. 8 shows a cogeneration system according to the first embodiment. The configuration shown in FIG. 8 shows one aspect of the present invention, and the present invention is not limited to such a configuration. In FIG. 8, the same reference numerals are given to the same parts as in FIG.
This cogeneration system 20 is an application example of the hot water supply system 2 already described, and in addition to the hot water supply units 4-1 and 4-2, this cogeneration system 20 is provided with a fuel cell unit 22 as an exhaust heat source. In other words, this cogeneration system 20 is also an example of a hot water supply system including the fuel cell unit 22 .
The fuel cell unit 22 is provided with a fuel cell 24 as an example of a heat source unit, and a heat exchanger 12-4, which is an example of a fourth heat exchanging portion, through an exhaust passage 8-9. flow to The heat of the exhaust gas HM3 is heat-exchanged with the heat medium HM1 circulating in the heat exchanger 12-4, and the heat medium HM1 heats the heat medium HM1 with the exhaust heat of the fuel cell . The heat medium HM1 is circulated through the heat medium circuit 8-1 by driving the circulation pump 14-3. The temperature on the inlet side of the heat exchanger 12-4 that circulates the heat medium HM1 is detected by the temperature sensor 10-7, and the temperature on the outlet side is detected by the temperature sensor 10-8.

The heat medium HM1 in the heat medium tank 6 of the hot water supply unit 4-1 circulates from the lower layer side of the hot water supply unit 4-1 to the heat medium circulation path 8-1, and after heat exchange with exhaust heat in the heat exchanger 12-4. , is returned to the upper layer side of the heat medium tank 6 . Thereby, hierarchical heat storage of the heat medium HM1 is performed. In the heat medium tank 6, the upper layer temperature of the heat medium HM1 is detected by the temperature sensor 10-1, the middle layer temperature is detected by the temperature sensors 10-9 and 10-10, and the lower layer temperature is detected by the temperature sensor 10-11. be.
During heat exchange between the heat medium HM1 of the hot water supply unit 4-1 and the water supply W, the flow rate of the water supply W flowing through the water supply path 8-2 is detected by the flow rate sensor 26-1. A temperature sensor 10-12 detects the temperature of the hot water HW discharged from the hot water supply unit 4-1.

During hot water supply, the flow rate of hot water HW flowing from hot water supply unit 4-1 to hot water supply path 8-6 is detected by flow rate sensor 26-2. The heating medium circuit 8-8 is provided with an accumulator 28 to control the pressure of the heating medium HM2. The outlet temperature of the heat exchanger 12-3 through which the heat medium HM2 circulates is detected by the temperature sensor 10-13, and the inlet temperature of the circulation pump 14-2 that circulates the heat medium HM2 is detected by the temperature sensor 10-14. be. The auxiliary heat source 18 for heating the heat medium HM2 by the heat exchanger 12-3 is provided with a burner 19 for generating combustion heat by burning gas fuel.

<Temperature sensor 10-1 of heat medium tank 6>
FIG. 9 shows the IX section of FIG. 8 in an enlarged manner. As shown in FIG. 9, the temperature sensor 10-1 of the heat medium tank 6 is installed in the upper layer of the heat medium tank 6. As shown in FIG. The position of this temperature sensor 10-1 may be determined according to the heating capacity and heating rate of the auxiliary heat source 18 of the burner 19. FIG. The position of the temperature sensor 10-1 is at least a volume level position that can secure time to complete the start-up of the burner 19 before the heat quantity of the heat medium HM1 is used for hot water supply, and detects the temperature of the heat medium HM1. If it is For example, if the regulated flow rate of 24 [liters/min] can be heated in 10 [seconds], set the volume level position corresponding to 4 [liters] or more of the heat medium amount, and set the heat medium temperature at that position. To detect. In the drawing, a dashed line 34 indicates a watershed line between the heat medium HM1 on the upper layer side and the low-temperature heat medium LHM1 on the lower layer side.

<Control Unit of Cogeneration System 20>
FIG. 10 shows an example of a control section of the cogeneration system 20. As shown in FIG. The controller 32 includes hot water supply unit controllers 36-1 and 36-2, a fuel cell unit controller 36-3, and a remote control controller 36-4, each of which is a computer having a communication function.
Hot water supply unit control section 36-1 is control means for hot water supply unit 4-1, and includes processor 38-1, memory section 40-1, system communication section 42-1, and input/output section (I/O) 44-1. In preparation, the hot water supply control of the hot water supply unit 4-1 is performed. The processor 38-1 executes an OS (Operating System) and a hot water supply control program in the memory unit 40-1, and communicates with the hot water supply unit control unit 36-2 and the fuel cell unit control unit 36- through the system communication unit 42-1. 3 and remote controller 36-4 to execute information processing necessary for hot water supply control. The memory unit 40-1 includes ROM (Read-Only Memory) and RAM (Random-Access Memory). A storage element such as a hard disk device or a non-volatile memory for storing data is used for the memory unit 40-1. The RAM constitutes a work area for information processing. The system communication unit 42-1 communicates with the system communication units of the hot water supply unit control unit 36-2, the fuel cell unit control unit 36-3, and the remote control control unit 36-4 by wire or wirelessly, and provides information necessary for control. send and receive The I/O 44-1 receives detection signals from various temperature sensors such as the temperature sensor 10-1 in the hot water supply unit 4-1 and the flow rate sensor 26-1, and receives control signals for the mixing valve 16-1 and circulation pump 14-1. to output

The hot water supply unit control section 36-2 is control means for the hot water supply unit 4-2, and includes a processor 38-2, a memory section 40-2, a system communication section 42-2, and an I/O 44-2. 2 hot water supply control. The processor 38-2 executes the OS and the hot water supply control program in the memory unit 40-2, and controls the hot water supply unit control unit 36-1, the fuel cell unit control unit 36-3, and the remote controller through the system communication unit 42-2. In cooperation with the unit 36-4, information processing necessary for hot water supply control is executed. The memory unit 40-2 includes ROM and RAM. A storage element such as a hard disk device or a non-volatile memory for storing data is used for the memory unit 40-2. The RAM constitutes a work area for information processing. The system communication unit 42-2 communicates with the system communication units of the hot water supply unit control unit 36-1, the fuel cell unit control unit 36-3, and the remote control control unit 36-4 by wire or wirelessly, and provides information necessary for control. send and receive The I/O 44-2 receives detection signals from various temperature sensors such as the temperature sensor 10-4 in the hot water supply unit 4-2, and the flow rate sensor 26-2. A control signal for the combustion control unit 46 is output.

The fuel cell unit control section 36-3 is control means for the fuel cell unit 22, and includes a processor 38-3, a memory section 40-3, a system communication section 42-3, and an I/O section 44-3. drive control. The processor 38-3 executes the OS and the hot water supply control program in the memory unit 40-3, and communicates with the hot water supply unit control units 36-1 and 36-2 and the remote control unit 36-4 via the system communication unit 42-3. It cooperates and executes the information processing necessary for hot water supply control. The memory unit 40-3 includes ROM and RAM. A storage element such as a hard disk device or a non-volatile memory for storing data is used for this memory section 40-3. The RAM constitutes a work area for information processing. The system communication unit 42-3 communicates with the system communication units of the hot water supply unit control units 36-1, 36-2 and the remote controller control unit 36-4 by wire or wirelessly, and transmits and receives information necessary for control. The I/O 44-3 receives detection signals from the temperature sensors 10-7 and 10-8 in the fuel cell unit 22 and outputs control signals for the circulation pump 14-3 and the fuel cell controller 48. FIG.

A remote control unit 36-4 is provided in a remote control device 50 independent of the hot water supply units 4-1 and 4-2 and the fuel cell unit 22. 3 through computer communication.

<Procedure for cooperative control>
FIG. 11 shows a main flow of cooperative control including hot water supply control of the control unit 32 . In this processing procedure, the remote control device 50 performs initialization (S41), input reception processing (S42), and display output processing (S43) when it is activated. Initial settings are performed by the user in the input acceptance process. This initial setting includes inputting the set temperature T of hot water supply to the hot water supply units 4-1 and 4-2 and switching ON/OFF of the operation of the fuel cell unit 22. FIG. In the display output process, input information and output information are presented on the display section of the remote control device 50 .

The fuel cell unit 22 executes initialization (S51), heat recovery processing (S52), and other management processing (S53). The heat recovery process is instructed to start or end by switching operation ON/OFF from the remote control device 50 . Management processing includes processing such as maintenance.

The hot water supply unit 4-1 executes initialization (S61), hot water supply processing (S62), and other management processing (S63). In the hot water supply process, a set temperature T for hot water supply is received from the remote control device 50 and the temperature of the hot water HW is controlled to the set temperature T. FIG. Then, in this hot water supply process, the hot water supply unit 4-2 is notified of the heat storage state of the heat medium tank 6 as "with heat storage" or "without heat storage". Other management includes processing such as maintenance.

The hot water supply unit 4-2 executes initialization (S71), hot water supply processing (S72), and other management processing (S73). In this hot water supply process, the set temperature T for hot water supply is received from the remote control device 50, the temperature of the hot water HW is controlled to the set temperature T, and the notification of "with heat storage" or "without heat storage" is received from the hot water supply unit 4-1. In response, temperature adjustment including heating control of the hot water HW by combustion control of the burner 19 is performed. As for other management, processing such as maintenance is reduced in the same manner as the hot water supply unit 4-1.

<Heat recovery treatment>
FIG. 12 shows the procedure of the heat recovery process of the fuel cell unit 22. As shown in FIG.
In the control of the fuel cell unit 22, it is determined whether the operation is ON (S81), and if the operation is ON (YES in S81), the fuel cell 24 is driven (S82). In driving the fuel cell 24, the rotation of the circulation pump 14-3 is controlled so that the temperature T8 detected by the temperature sensor 10-8 becomes a constant temperature, for example, 75[° C.] (S83).
If the operation is not ON (NO in S81), the driving of the fuel cell 24 is stopped (S84). When the driving of the fuel cell 24 is stopped, the rotation of the circulation pump 14-3 is stopped (S85).

<Hot water supply processing [1-1]>
FIG. 13 shows the procedure of the hot water supply process [1-1] of the hot water supply unit 4-1.
It is determined whether hot water supply is used (S91), and if not hot water supply (NO in S91), circulation pump 14-1 is stopped (S92), and this hot water supply process ends.
If hot water supply is used (YES in S91), it is determined whether T1>T2 (S93). ] The rotation speed of the circulation pump 14-1 is controlled so as to reach (or approach) a high temperature (T+α) (S94). If not T1>T2 (NO in S93), the circulation pump 14-1 is stopped (S95).
After S94 or S95, it is determined whether T1<T+β (S96), and if T1<T+β (YES in S96), hot water supply unit control section 36-1 sends hot water supply unit control section 36-2 "no heat storage ' is transmitted (S97), and if T1<T+β is not satisfied (NO in S96), 'Heat accumulation is present' is transmitted (S98). After these transmissions, the hot water supply unit 4-1 controls the temperature of the hot water HW to be discharged to the set temperature T (or approaches T) and discharges hot water (S99).

<Hot water supply processing [1-2]>
FIG. 14 shows the procedure of the hot water supply process [1-2] of the hot water supply unit 4-1.
It is determined whether hot water supply is to be used (S101), and if not hot water supply (NO in S101), circulation pump 14-1 is stopped (S102), and this hot water supply process ends.
If hot water supply is used (YES in S101), it is determined whether T1>T2 (S103). The rotational speed of the circulating pump 14-1 is controlled to (or approach) (T+α) (S104). If not T1>T2 (NO in S103), the circulation pump 14-1 is stopped (S105).
After S104 or S105, it is determined whether T1<T+β (S106), and if T1<T+β (YES in S106), hot water supply unit control section 36-1 sends hot water supply unit control section 36-2 "no heat storage ' is transmitted (S107), and if T1<T+β is not satisfied (NO in S106), 'Heat accumulation is present' is transmitted (S108).

In this control, it is determined whether T3<T (S109), and if T3<T (YES in S109), the mixing valve 16-1 controls the hot water supply passage 8-4 side to be fully opened (S110). , T3<T (NO in S109), based on the detected temperature T12, the opening ratio of the mixing valve 16-1 is controlled so that the hot water HW reaches the set temperature T (S111).

<Hot water supply processing [2-1]>
FIG. 15 shows the procedure of the hot water supply process [2-1] of the hot water supply unit 4-2.
It is determined whether hot water supply is used (S121), and if not hot water supply (NO in S121), the circulation of the heating medium HM2 is stopped, and this hot water supply process ends.
If hot water supply is used (YES in S121), it is determined whether "no heat storage" has been received (S123). If "no heat storage" is received (YES in S123), the heat medium HM2 is circulated (S124). If "no heat storage" is not received (NO in S123), it is determined whether T4<T (S125). If T4<T (YES in S125), the process proceeds to S124. If not T4<T (NO in S125), the circulation of the heat medium HM2 is stopped (S126).
When the heat medium HM2 is circulated in S124, it is determined whether T4<T (S127). If T4<T (YES in S127), the temperature of the mixed water mHW is set by the mixing valve 16-2. The temperature is controlled to T (S128). If not T4<T (NO in S127), the mixing valve 16-2 is fully opened to the side of the bypass 8-7, and only hot water HW is supplied from the hot water supply unit 4-1 (S129).

<Hot water supply processing [2-2]>
FIG. 16 shows the procedure of the hot water supply process [2-2] of the hot water supply unit 4-2.
It is determined whether hot water supply is used (S131), and if hot water supply is used (YES in S131), it is determined whether "no heat storage" is received (S132). If "no heat storage" is received (YES in S132), the circulation pump 14-2 is driven (S133) to circulate the heat medium HM2. Based on the temperature T13 detected by the temperature sensor 10-13, the combustion amount of the burner 19 is controlled so that the temperature of the heat medium HM2 becomes a constant temperature. This control is executed by the combustion control section 46 of the burner 19 . If "no heat storage" is not received (NO in S132), the circulation pump 14-2 is stopped (S136), and combustion of the burner 19 is stopped (S137).
After S134 and S137, it is determined whether T4<T (S138). If T4<T (YES in S138), the mixed water mHW reaches the set temperature T based on the temperature T4 detected by the temperature sensor 10-4. (S139). If T4<T (NO in S138), the hot water supply path 8-6 is supplied with the hot water HW controlled to the set temperature T from the hot water supply unit 4-1, so the bypass path 8-7 side is fully opened. Then, the mixing valve 16-2 is controlled to discharge hot water HW at the set temperature T (S140).
In S131, if hot water supply is not used (NO in S131), circulation of heat medium HM2 is stopped by stopping circulation pump 14-2 (S141), combustion of burner 19 is stopped (S142), and mixing valve 16- 2 controls the bypass 8-7 to be fully closed (S143), and terminates this control. In the case of "with heat storage", the bypass 8-7 may be controlled to be fully open.

<Linked communication processing>
FIG. 17 shows a sequence of cooperative communication processing of hot water supply units 4-1 and 4-2, fuel cell unit 22 and remote control device 50. In FIG.
Regarding the power generation-related process F1, the remote control device 50 gives an ON instruction for the fuel cell (S201), an operation display for the fuel cell 24 (S202), an OFF instruction for the fuel cell 24 (S203), an OFF display for the fuel cell 24 (S204), and the like. processing is included.

In the power generation-related process F1, the fuel cell unit 22 drives the circulation pump 14-3 in response to the fuel cell ON instruction (S201) (S211), and notifies the activation of the fuel cell 24 in response to the operation display of the fuel cell 24 (S202). S212), control of circulation pump 14-3 for target hot water temperature: 75°C (S213), fuel cell 24 OFF instruction (S203) to stop operation of fuel cell 24 (S214), circulation pump until heat quantity drops 14-3 includes exhaust heat recovery (S215) and stopping the fuel cell 24 (S216).

In the hot water supply unit 4-1, exhaust heat recovery (no control or communication) (S221) is included as processing F1 related to power generation. (S222), send "with heat storage" (S223), start heat storage hot water supply (S224), decrease heat storage (warm-up instruction) (S225), turn off hot water supply flow rate (S226), stop heat storage hot water supply (S227). In addition, as processing F3 for "no heat storage" related to hot water supply, "no heat storage" is transmitted (S228), the hot water supply flow rate is turned on (S229), and if there is a calorie, heating and hot water supply is started (S230), and the hot water supply flow rate is turned off (S231). ), and stopping hot water supply (S232).

In the hot water supply unit 4-2, the hot water supply flow rate is turned ON (S241), the hot water supply mode is determined (storage hot water supply) (S242), the warm-up operation is performed (S243), and mixing control is performed based on the outlet hot water temperature. (S244) and hot water supply flow rate OFF (S245). In addition, as a process F3 in the case of "no heat storage" in relation to hot water supply, hot water supply mode determination (water supply heat gas hot water supply or gas hot water supply) (S246) is performed in response to transmission of "no heat storage" from hot water supply unit 4-1. Flow rate ON (S247), transmission of hot water supply use (S248), gas combustion hot water supply (S249), hot water supply flow rate OFF (S250), hot water supply stop transmission (S251) in response to hot water supply stop (S232) of hot water supply unit 4-1, etc. processing is included.

<Effect of Example 1>
According to the first embodiment, the following effects are obtained.
(1) The hot water HW stored in the heat medium tank 6 can be effectively used, and the hot water supply capacity can be improved.
(2) Exchanging the exhaust heat obtained from the gas engine or the fuel cell with the heat medium HM1 in the heat medium tank 6, heat-exchanging the heat of the heat medium HM1 with the hot water HW, storing the hot water HW, and supplying the hot water. Available.
(3) In the hot water supply unit 4-1, heat exchange is performed so that the temperature of the water supply W is higher than the set temperature T by, for example, α=5° C. (T+α). The hot water HW (temperature=T+α) after heat exchange and the feed water W before heat exchange can be mixed by the mixing valve 16-1, adjusted to the set temperature T, and hot water can be supplied.
(4) When the temperature T1 detected by the temperature sensor 10-1 in the heat medium tank 6 becomes less than the temperature (T+β), the temperature of the hot water HW after heat exchange is expected to fall below the temperature (T+α). Therefore, when the detected temperature T1 becomes lower than the temperature (T+β), the combustion of the burner 19 of the auxiliary heat source 18 is started to prevent the temperature of the hot water HW from dropping.
(5) Even if the temperature of the heat medium HM1 in the heat medium tank 6 becomes lower, if it is higher than the temperature T2 of the feed water W, the heat of the heat medium HM1 is exchanged with the feed water W and used. can be effectively used.
(6) Since the heat medium HM1 in the heat medium tank 6 is not used for heat exchange to directly supply hot water, there is no need to secure the water quality of the heat medium HM1 in the heat medium tank 6 (countermeasures against Legionella bacteria), and the heat medium tank 6 is heated. It is economical because no treatment such as sterilization is required.
(7) The heat medium tank 6 may be open to the atmosphere, there is no need to consider the pressure resistance function of the heat medium tank 6, and the pressure reducing valve on the water supply W side is not required. The configuration of 8-3 can be simplified.
(8) Combustion heat of the burner 19 of the auxiliary heat source 18 is used to exchange heat with the heat medium HM2, and the heat of the heat medium HM2 is used to heat the hot water hHW. The temperature is raised.
(9) Using the mixing valve 16-1 of the hot water supply unit 4-1, if the temperature of the hot water HW from the heat exchanger 12-1 is equal to or higher than the set temperature T, the hot water HW and the feed water W are mixed, The temperature of the hot water HW is adjusted to the set temperature T. In this case, when the hot water supply unit 4-1 can discharge hot water at the set temperature T, the mixing valve 16-2 of the hot water supply unit 4-2 is fully opened on the side of the bypass 8-7, and the heat medium HM2 is supplied by the burner 19. Do not heat.
(10) When the temperature of the heat medium on the upper layer side of the heat medium tank 6 becomes lower than the set temperature T+β, the burner 19 is started to be driven. The burner 19 is provided with a heat medium circuit 8-8 and a heat exchanger 12-2, and exchanges the heat of the heat medium HM2 with the hot water HW. That is, the hot water HW is indirectly heated by the burner 19 to obtain the hot water hHW.
(11) During hot water supply, when the temperature of the upper layer of the heat medium tank 6 drops below the set temperature T+β, the burner 19 is driven first to heat the heat medium HM2, and the heat medium of the hot water supply unit 4-1 is Prepare for running out of hot water due to insufficient heat of HM1.
(12) When the detected temperature T4 becomes less than the set temperature T due to the lack of hot water in the hot water supply unit 4-1, the combustion heat of the burner 19 is heat-exchanged with the heat medium HM2, the heat of the heat medium HM2 is heat-exchanged with the hot water HW, Mixed water mHW to be discharged is adjusted to a set temperature T by a mixing valve 16-2 using the heated hot water HW and the hot water HW before heat exchange.
(13) Even if the temperature of the hot water HW obtained from the mixing valve 16-1 of the hot water supply unit 4-1 drops rapidly, the heating medium HM2 on the burner 19 side is preheated. The mixed water mHW can be controlled to the set temperature T by the mixing ratio of the hot water HW before heating and the hot water HW after heating, and the hot water temperature can be stabilized.
(14) When the heat amount of the heat medium tank 6 is insufficient, the mixing valve 16-1 is fully opened on the hot water HW side so that the heat amount of the heat medium HM1 in the heat medium tank 6 can be fully utilized when the hot water HW is discharged.
(15) Hot water supply units 4-1 and 4-2 may be integrated or separated. If the hot water supply units 4-1 and 4-2 are made separable, the degree of freedom of installation and the facilitation of maintenance can be achieved.
(16) When the hot water is not to be discharged, under the condition that the temperature T5 detected by the temperature sensor 10-5 is less than the set temperature T (T5<T), the mixing valve 16-2 is fully opened to the heat exchanger 12-2 side. In other words, since the bypass 8-7 side is fully closed, even if the bypass 8-7 side is fully opened at the start of hot water supply, a corresponding amount of time is required for switching, and the mixing valve 16-2 has Since the hot water HW after heating on the side of the heat exchanger 12-2 flows out, it is possible to prevent the hot water HW from stagnation.
(17) For example, when a maximum flow rate of 24 [liters/min] is passed as the water supply flow rate, there is a grace time of about 10 [seconds] until the hot water HW that has exchanged heat with the heat medium HM1 of the temperature sensor 10-1 flows out. Therefore, even if the detected temperature T1 of the temperature sensor 10-1 becomes less than the set temperature T+β (T1<T+β), the heat medium HM2 in the heat exchanger 12-2 can be sufficiently heated during such grace time. Therefore, the temperature of discharged hot water can be stabilized even if the circulation delay of the heat medium HM1 occurs.

FIG. 18 shows the relationship between the water supply temperature of the hot water supply unit 4-2 and the heat medium HM2 according to the second embodiment.
Embodiment 2 shows an example of the hot water supply capacity of the hot water supply unit 4-2 alone, with the horizontal axis representing the temperature of the supplied water and the vertical axis representing the transition of the temperature of the heat medium HM2. As is clear from this result, in the hot water supply unit 4-2, the set temperatures Ta, Tb, and Tc of the water supply temperature and hot water HW (for example, Ta = 35 [°C], Tb = 40 [°C], Tc = 45 [°C] °C]), the temperature of the heat medium HM2 is controlled.

FIG. 19 shows a hot water supply system 52 according to the third embodiment. 19, the same reference numerals are given to the same parts as those of the hot water supply system 2 shown in FIG. 1 or the cogeneration system 20 shown in FIG.
The hot water supply system 52 includes the hot water supply unit 4-1 and the fuel cell unit 22 described above, and is configured independently of the hot water supply unit 4-2. That is, the hot water supply system 52 can be configured as a hot water source that supplies hot water not only to the hot water supply unit 4-2 but also to other hot water supply systems and hot water supply devices. Since each part is as described above, it is given the same reference numeral and its explanation is omitted.

FIG. 20 shows a hot water supply system according to the fourth embodiment. In FIG. 20, the same parts as in FIG. 1 or 8 are given the same reference numerals.
This hot water supply system 52 is an example of a hot water supply unit 4-2 separated from the hot water supply unit 4-1. Hot water HW to be controlled can be discharged.
This hot water supply system 52 has a hot water supply function, a heating function and a bathtub water reheating function. Hot water HW is supplied to the hot water supply path 8-6 from the hot water supply unit 4-1 side, and hot water HW or mixed water mHW is discharged. In this embodiment, heat exchangers 12-31, 12-32, 12-33 for exchanging combustion heat of the burner 19 are provided. The heat exchanger 12-31 heat-exchanges mainly the sensible heat of the combustion heat to the heat medium HM2, the heat exchanger 12-32 heat-exchanges mainly the latent heat of the combustion heat to the heat medium HM2, and the heat exchanger 12-33 exchanges mainly the latent heat of the combustion heat with the hot water HW in the hot water supply passage 8-6. Therefore, in this embodiment, the heat of the heat medium HM2 is exchanged with the hot water HW by the heat exchanger 12-2, and mainly the latent heat of the combustion heat is exchanged by the heat exchanger 12-33.

The burner 19 has its gas combustion amount controlled by a combustion control unit 46, and the control of this combustion control unit 46 includes air supply control by a fan, proportional valve control for the hot water supply request of the fuel gas G, and combustion switching control of the burner 19. be
A remote control device 50 is connected to the control unit 32 via a communication line 56, and the remote control device 50 is provided with the above-described remote control control unit 36-4. The communication line 56 may be connected to the hot water supply system 52 to acquire information on the temperature T1 detected by the temperature sensor 10-1, notify the set temperature T, and the like.
During heating, the heating medium HM2 is circulated through the heating panel 58-1, the convector 58-2, and other radiators through a heating circuit 8-10 branched from the heating medium circulation path 8-8.
A heat exchanger 12-5 for exchanging the heat of the heat medium HM2 with the bath water BW is installed in the heat medium circulation path 8-8. A bathtub 60 is connected to the heat exchanger 12-5 via a reheating circuit 8-11. Therefore, when the bathtub water BW is reheated, the circulation pump 14-4 is driven to circulate the bathtub water BW through the reheating circulation path 8-11 to the heat exchanger 12-5, and the heat of the heating medium HM2 is transferred to the bathtub water BW. is heat exchanged.

The hot water supply system 52 may use the control unit 32 (FIG. 10) already described. In this embodiment 4, control of the mixing valve 16-2 and combustion control of the burner 19 are carried out based on the determination by the controller 32 that there is no remaining hot water. The determination that there is no remaining hot water can be made by comparing the temperature T1 detected by the temperature sensor 10-1 and the set temperature T. For example, when T1<T, only the hot water HW is clogged, which is set without using auxiliary heating. When hot water cannot be supplied at temperature T, it is sufficient that there is no remaining hot water.
According to such a hot water supply system 52, it is possible to heat and control the hot water HW by the heating medium HM2 by the hot water adjustment function similar to that of the hot water supply unit 4-2.

<Effects of Examples 1 to 4>
According to Examples 1 to 4, the following effects can be obtained.
(1) According to such a configuration, the hot water supply function of the hot water supply system 52 can be utilized for the temperature adjustment function of the hot water supply unit 4-2. Therefore, an existing water heater can be used when installing the hot water supply unit 4-2.
(2) By using such a system, as described above, the heat medium HM1 in the heat medium tank 6 is used first, so that the utilization efficiency of the heat medium HM1 in the heat medium tank 6 can be improved. Moreover, the hot water HW can be stably discharged at the set temperature T.
(3) In the above embodiment, the heat medium HM2 is heated to 75° C. or higher by performing a combustion operation in advance. Heated hot water HW is obtained and is extremely hygienic.

[Other embodiments]
a) In the above embodiment, the hot water supply system 52 does not have a hot water storage tank, but it may be configured to have a hot water storage tank.
b) In the first embodiment, the heating medium circuit 8-8 is provided with the accumulator 28, but the accumulator 28 may be omitted.

As described above, the most preferable embodiment and the like of the present invention have been described. The invention is not limited to the above description. Various modifications and changes are possible for those skilled in the art based on the gist of the invention described in the claims or disclosed in the detailed description. It goes without saying that such modifications and changes are included in the scope of the present invention.

In the hot water supply system of the present invention, heat is stored by the heat medium in the heat medium tank, and the heat of this heat medium can be efficiently used for heating hot water, and the hot water outlet temperature can be stabilized during hot water supply.

2 Hot water supply system 4-1 First hot water supply unit 4-2 Second hot water supply unit 6 Heating medium tank 8-1 Heating medium circulation path 8-2 Water supply path 8-3 Heating medium circulation path 8-4 Hot water supply path 8-5 Bypass path 8-6 Hot water supply path 8-7 Bypass path 8-8 Heat medium circulation path 8-9 Heat medium path 10-1, 10-2, 10-3, 10-4, 10-5, 10-6, 10 -7, 10-8, 10-9, 10-10, 10-11, 10-12, 10-13, 10-14 Temperature sensor 12-1, 12-2, 12-3, 12-4, 12- 31, 12-32, 12-33 heat exchanger 14-1, 14-2, 14-3 circulation pump 16-1, 16-2 mixing valve 18 auxiliary heat source 19 burner 20 cogeneration system 22 fuel cell unit 24 fuel cell 26-1, 26-2 Flow rate sensor 28 Accumulator 32 Control section 34 Broken line 36-1, 36-2 Hot water supply unit control section 36-3 Fuel cell unit control section 36-4 Remote control section 38-1, 38-2, 38 -3 processors 40-1, 40-2, 40-3 memory units 42-1, 42-2, 42-3 system communication units 44-1, 44-2, 44-3 input/output units (I/O)
46 combustion control unit 48 fuel cell control unit 50 remote controller 52 hot water supply system 56 communication line 58-1 heating panel 58-2 convector 60 bathtub

Claims (3)

A hot water supply system using a hot water supply unit for generating hot water from water supply and an auxiliary heat source for heating the hot water when the hot water generated by the hot water supply unit is lower than a set temperature,
a heat storage tank for storing and storing the first heat medium;
a first heat exchange means for exchanging heat between the first heat medium taken out from the upper layer of the heat storage tank and feed water, and for controlling the circulation amount of the first heat medium;
a second heat exchange means for supplying hot water at a set temperature by heat exchange between the second heat medium heated by the combustion heat of the combustion means and the hot water;
a temperature sensor that correlates the time to complete the combustion start-up of the combustion means with the volumetric position of the heat storage tank and detects the temperature of the first heat medium at the volumetric position;
a control unit that controls at least the circulation amount of the first heat medium using the detected temperature of the first heat medium;
hot water system. A hot water supply method using a hot water supply unit for generating hot water from water supply and an auxiliary heat source for heating the hot water when the hot water generated by the hot water supply unit is lower than a set temperature,
a step of storing heat by storing the first heat medium in the heat storage tank;
A step in which a first heat exchange means exchanges heat between the first heat medium taken out from the upper layer of the heat storage tank and feed water, and a circulating amount of the first heat medium is controlled;
a step in which the second heat exchange means discharges hot water at a set temperature by heat exchange between the second heat medium heated by the combustion heat of the combustion means and the hot water;
a temperature sensor correlating the time at which the combustion means completes combustion startup and the volumetric position of the heat storage tank, and detecting the temperature of the first heat medium at the volumetric position;
a step in which a control unit controls at least the circulation amount of the first heat medium using the detected temperature of the first heat medium;
hot water supply method including; A hot water supply unit for use in a hot water supply system using both a hot water supply unit that generates hot water from supplied water and an auxiliary heat source that heats the hot water when the hot water generated by the hot water supply unit is lower than a set temperature,
a heat storage tank for storing and storing the first heat medium;
a first heat exchange means for exchanging heat between the first heat medium taken out from the upper layer of the heat storage tank and feed water, and for controlling the circulation amount of the first heat medium;
a second heat exchange means for supplying hot water at a set temperature by heat exchange between the second heat medium heated by the combustion heat of the combustion means and the hot water;
a temperature sensor that correlates the time to complete the combustion start-up of the combustion means with the volumetric position of the heat storage tank and detects the temperature of the first heat medium at the volumetric position;
a control unit that controls at least the circulation amount of the first heat medium using the detected temperature of the first heat medium;
hot water unit.

Images