JP2017152267A - Fuel cell system, fuel cell unit, and method of controlling operation of fuel cell unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively produce hot water by utilizing the waste heat of a fuel cell unit.SOLUTION: A fuel cell system 1 includes fuel cell units 100-102, hot water tanks 210-212, and a transfer means 300. The transfer means 300 transfers hot water produced by recovering waste heat of the fuel cell units 100-102 to the hot water tanks 210-212. A control section 150 of the fuel cell unit 100 that is set as a master device controls the transfer means 300 so as to transfer the hot water from the fuel cell unit 100-102 to the hot water tank 211 that has the smallest amount of hot water storage.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel cell system, a fuel cell unit, and a fuel cell unit operation control method.

  In recent years, it has become widespread that hot water is generated using the exhaust heat of a fuel cell unit, and the generated hot water is stored in a hot water storage unit for use in a bath or a heating device. In addition, in order to stabilize power supply, a plurality of fuel cell units are increasingly installed in customer facilities. Thus, a fuel cell system including a plurality of fuel cell units and a plurality of hot water storage units has been proposed (Patent Documents 1 and 2).

  In the fuel cell system described in Patent Document 1, hot water generated in each fuel cell unit is stored in a hot water tank connected to each fuel cell unit, and the hot water stored in each hot water tank is collectively collected as a heating demand or the like. It is used as a heat source.

  Moreover, in the fuel cell system described in Patent Document 2, a fuel cell unit and a hot water tank for a dwelling unit are installed for each dwelling unit of the apartment, and a hot water tank for a dwelling unit installed in a dwelling unit on the same floor is connected to each other. The hot water tanks for each dwelling unit installed in the dwelling unit on another floor are connected with the floor hot water tank. Hot water is transferred between the dwelling units on the same floor via a hot water tank for the dwelling unit, and hot water is transferred between dwelling units on different floors via the floor hot water tank. ing.

JP 2004-221021 A JP 2007-101004 A

  In the fuel cell system disclosed in Patent Document 1, for example, if an error occurs in the hot water storage unit due to a failure of the hot water storage unit, the fuel cell unit connected to the hot water storage unit cannot generate power. In addition, when the hot water storage unit is full, if you try to continue power generation with the fuel cell unit connected to the hot water storage unit, the fuel cell unit will throw away the generated hot water and continue power generation. Hot water is wasted.

  Moreover, in the fuel cell system described in Patent Document 2, since the hot water is transferred through the hot water storage tank for the dwelling unit or the floor hot water storage tank, the temperature of the hot water may change due to the transfer. Therefore, in order to obtain hot water having a temperature desired by the user, it is necessary to reheat the hot water or add water after the transfer to the hot water storage tank for the dwelling unit.

  As described above, the conventional fuel cell system has a problem that hot water cannot be efficiently generated using the exhaust heat of the fuel cell unit.

  An object of the present invention has been made in view of the above problems, and is a fuel cell system, a fuel cell unit, and a plurality of fuel cell units capable of efficiently generating hot water using exhaust heat of the fuel cell unit. An operation control method is provided.

  A fuel cell system according to an embodiment of the present invention is a fuel cell system including a fuel cell unit and a plurality of hot water storage units, wherein the plurality of hot water generated by collecting waste heat of the fuel cell unit is collected. And a controller for controlling the transfer means to transfer hot water to the hot water storage unit having the smallest amount of hot water storage among the plurality of hot water storage units. And

The fuel cell unit according to an embodiment of the present invention is a fuel cell unit, and the fuel cell unit can transfer hot water generated by recovering exhaust heat of the fuel cell unit to a hot water storage unit. And a control unit that controls the transfer means to transfer hot water to the hot water storage unit having the smallest amount of hot water storage in the plurality of hot water storage units.

  A fuel cell unit operation control method according to an embodiment of the present invention is a fuel cell unit operation control method in a fuel cell system including a fuel cell unit and a plurality of hot water storage units. Comprises a transfer means configured to transfer hot water generated by recovering exhaust heat of the fuel cell unit to the plurality of hot water storage units, and detecting the hot water storage unit with the least amount of hot water stored; And a first control step for controlling the transfer means to transfer hot water generated by the fuel cell unit to the hot water storage unit having the smallest amount.

  According to the fuel cell system, the fuel cell unit, and the operation control method for the fuel cell unit according to one embodiment of the present invention, hot water can be efficiently generated using the exhaust heat of the fuel cell unit.

It is a figure which shows an example of a structure of the fuel cell system which concerns on one Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the fuel cell system which concerns on one Embodiment of this invention. It is a figure which shows an example of a structure of the fuel cell system which concerns on the modification of this invention. It is a figure which shows an example of a structure of the fuel cell system which concerns on the modification of this invention.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

[System configuration]
FIG. 1 is a diagram illustrating an example of a configuration of a fuel cell system 1 according to an embodiment of the present invention. The fuel cell system 1 includes fuel cell units 100, 101, 102, hot water storage units 200, 201, 202, transfer means 300, and transfer means 400. The fuel cell system 1 shown in FIG. 1 includes three fuel cell units 100 to 102 and three hot water storage units 200 to 202. The number of fuel cell units and hot water storage units included in the fuel cell system 1 is as follows. It is not limited to. In the line connecting the fuel cell units 100 to 102 and the hot water storage units 200 to 202 shown in FIG. 1, the solid line indicates the hot water path, and the broken line indicates the water path.

  Each of the fuel cell units 100 to 102 generates electric power by an electrochemical reaction of gas, and supplies the generated electric power to the customer facility 500. In addition, each of the fuel cell units 100 to 102 generates hot water using exhaust heat generated when generating electric power. The generated hot water is transferred to the hot water storage units 200 to 202 by the transfer means 300. For the fuel cell units 100 to 102, for example, a polymer electrolyte fuel cell (PEFC) or a solid oxide fuel cell (SOFC) can be used.

  In the fuel cell system 1, the fuel cell units 100 to 102 are set as a parent device or a child device, and the child device performs power generation or the like based on an instruction or the like of the parent device. In the example of FIG. 1, it is assumed that the fuel cell unit 100 is set as a parent device, and the fuel cell units 101 and 102 are set as child devices. Details of the functions of the fuel cell units 100 to 102 will be described later.

  The hot water storage unit 200 has a hot water storage tank 210 and a backup heat source machine 220, the hot water storage unit 201 has a hot water storage tank 211 and a backup heat source machine 221, and the hot water storage unit 202 has a hot water storage tank 212 and a backup heat source machine 222.

  Hot water generated by collecting exhaust heat from the fuel cell units 100 to 102 is transferred and stored in the hot water storage tanks 210 to 212 by the transfer means 300. Hot water stored in the hot water storage tanks 210 to 212 is transferred to the customer facility 500 by the transfer means 400.

  The hot water storage tanks 210 to 212 may be set so as to store hot water at different temperatures. In the example of FIG. 1, the hot water tank 210 is set to store 75 ° C. hot water, the hot water tank 211 is set to store 60 ° C. hot water, and the hot water tank 212 is set to store 45 ° C. hot water. ing. The temperature setting of the hot water stored in the hot water storage tanks 210 to 212 may be performed by the fuel cell unit 100 which is the parent apparatus using the hot water usage history in the customer facility 500, for example. For example, if the fuel cell unit 100 that is the parent device determines from the usage history of hot water that the usage frequency of hot water near 75 ° C., 60 ° C., and 45 ° C. is high in the customer facility 500, The temperature settings of hot water stored in 212 are set to 75 ° C., 60 ° C., and 45 ° C., respectively. Moreover, the temperature setting of the hot water tanks 210 to 212 may be performed directly by the user, for example.

  In addition, when hot water is supplied to the customer facility 500, the hot water stored in the hot water storage tanks 210 to 212 is heated by the backup heat source units 220 to 222, or water is added, respectively. After adjusting to the desired temperature, the customer facility 500 may be supplied. For example, when the customer facility 500 desires 62 ° C. hot water, the hot water stored in the hot water storage tank 211 may be heated to 62 ° C. by the backup heat source unit 221 and then supplied to the customer facility 500. . For example, when the customer facility 500 desires hot water of 42 ° C., the hot water stored in the hot water storage tank 212 may be added to water at 42 ° C. and then supplied to the customer facility 500.

  The transfer means 300 includes, for example, an on-off valve, a pipe, a pump, and the like, and includes on-off valves 310, 320, and 330. The on-off valve 310 is connected between all of the fuel cell units 100 to 102 and the hot water storage tank 210, the on-off valve 320 is connected between all of the fuel cell units 100 to 102 and the hot water storage tank 211, and the on-off valve 330 is It is connected between all of the fuel cell units 100 to 102 and the hot water tank 212. The transfer means 300 generates hot water generated by collecting the exhaust heat of the fuel cell units 100 to 102 with the on-off valves 310 to 330 being closed or open based on the control from the fuel cell unit 100 which is a parent device. Is transferred to a selected hot water storage tank among the hot water storage tanks 210 to 212. For example, when all the hot water generated in the fuel cell units 100 to 102 is transferred to the hot water storage tank 211, the open / close valve 310 is closed, the open / close valve 320 is open, and the open / close valve 330 is closed.

  The transfer unit 400 includes, for example, an on-off valve, a pipe, a pump, and the like, and includes the on-off valves 410, 420, and 430. The on-off valve 410 is connected between the hot water tank 210 and the customer facility 500, the on-off valve 420 is connected between the hot water tank 211 and the customer facility 500, and the on-off valve 430 is connected to the hot water tank 212 and the customer facility 500. Connected between. The transfer means 400 transfers the hot water stored in the hot water storage tanks 210 to 212 to the customer facility 500 by closing the open / close valves 410 to 430 based on the control from the fuel cell unit 100 which is the parent device. To do. For example, when 60 ° C. hot water is transferred to the customer facility 500, the on-off valve 410 is closed, the on-off valve 420 is opened, and the on-off valve 430 is closed. In addition, when the customer facility 500 requests hot water having a temperature intermediate between the temperatures set in the hot water tanks 210 to 212, two or more of the on-off valves 410 to 430 are opened to supply hot water to the customer facility 500. You may supply. For example, when the customer facility 500 requests hot water of 52 ° C., the on / off valve 410 is closed and the on / off valves 420 and 430 are opened to transfer the hot water of 52 ° C. to the customer facility 500. Good.

  The customer facility 500 uses hot water supplied from the hot water tanks 210 to 212 for a bath, a heating device, and the like. In addition, the customer facility 500 consumes the power supplied from the fuel cell units 100 to 102.

  Next, details of the functions of the fuel cell units 100 to 102 will be described. The fuel cell unit 100 that is the parent device and the fuel cell units 101 and 102 that are the child devices can adopt the same configuration. Therefore, the details of the function will be described below using the fuel cell unit 100 as an example. .

  The fuel cell unit 100 includes a fuel reforming unit 110, a fuel cell stack 120, an inverter 130, an exhaust heat recovery unit 140, a control unit 150, a storage unit 160, and a communication unit 170.

  The fuel reforming unit 110 steam reforms a gas supplied from the outside to generate hydrogen gas. Then, the fuel reforming unit 110 supplies the generated hydrogen gas to the fuel cell stack 120. The gas supplied from the outside is, for example, city gas or propane gas. Kerosene can also be used instead of gas.

  The fuel cell stack 120 reacts hydrogen gas supplied from the fuel reforming unit 110 with oxygen in the air to generate DC power. The fuel cell stack 120 supplies the generated DC power to the inverter 130. In addition, the fuel cell stack 120 discharges the exhaust heat generated with the generation of DC power to the exhaust heat recovery unit 140.

  The inverter 130 converts the DC power supplied from the fuel cell stack 120 into AC power, and supplies the converted AC power to the customer facility 500.

  The exhaust heat recovery unit 140 recovers exhaust heat generated with the generation of DC power in the fuel cell stack. The exhaust heat recovery unit 140 generates hot water by exchanging the recovered exhaust heat with water circulating from the outside. The exhaust heat recovery unit 140 can generate hot water at a desired temperature by changing the amount of water circulating under the control of the control unit 150.

  The control unit 150 controls and manages the entire fuel cell unit 100, and can be configured by a processor, for example. The control unit 150 reads out and executes a program stored in the storage unit 160 to realize various functions. Details of the processing of the control unit 150 will be described later.

  The storage unit 160 stores information necessary for processing of the fuel cell unit 100 and a program describing processing contents for realizing each function of the fuel cell unit 100.

  The communication unit 170 communicates with the fuel cell units 101 and 102 as the child devices, the on-off valves 310 to 330, the on-off valves 410 to 430, and the like.

  Hereinafter, details of the processing of the control unit 150 of the fuel cell unit 100 which is the parent device will be described. The hot water storage tanks 210 to 212 will be described assuming that the hot water storage capacity of the hot water storage tank 211 is the smallest.

  First, when the power consumption of the customer facility 500 increases and the power generation of the fuel cell units 100 to 102 is necessary, the control unit 150 detects the hot water storage tank 211 having the smallest amount of hot water storage. The amount of hot water stored in the hot water storage tanks 210 to 212 can be detected by, for example, float-type water amount sensors provided in the hot water storage tanks 210 to 212, respectively.

  Next, in the fuel cell units 100 to 102, the control unit 150 sets so as to generate hot water having a set temperature of 60 ° C. in the hot water storage tank 211 having the smallest amount of hot water storage. For example, the control unit 150 sets the temperature of hot water generated by the own device (fuel cell unit 100) to 60 ° C., which is the set temperature of the hot water storage tank 211 having the smallest amount of stored hot water. In addition, the control unit 150 instructs the fuel cell units 101 and 102 that are child devices to generate 60 ° C. hot water that is the set temperature of the hot water storage tank 211 with the smallest amount of hot water storage and generate power. To do. Thereafter, the fuel cell unit 100 which is the parent device starts power generation, and the fuel cell units 101 and 102 which are child devices also start power generation when receiving this instruction. Thereby, in the fuel cell units 100 to 102, power generation is performed, and exhaust heat generated by the power generation is recovered to generate hot water of 60 ° C.

  Then, the control part 150 controls the transfer means 300 so that the hot water produced | generated by the fuel cell units 100-102 may be transferred to the hot water storage tank 211 with the least amount of hot water storage. Based on this control, in the transfer means 300, the on-off valve 310 is closed, the on-off valve 320 is open, and the on-off valve 330 is closed. And the hot water of 60 degreeC produced | generated by the fuel cell units 100-102 is transferred to the hot water storage tank 211 with the least amount of hot water storage.

  Note that the control unit 150 may control the fuel cell units 100 to 102 so as to generate hot water of the hot water storage unit having a relatively high temperature when there are a plurality of hot water storage units having the smallest amount of hot water storage. Good. For example, in the fuel cell system 1 shown in FIG. 1, it is assumed that the amount of hot water stored in the hot water storage tanks 210 and 211 is the smallest. In this case, the control unit 150 generates hot water of the hot water storage unit 200 (set temperature 75 ° C.) having a relatively high temperature in the hot water storage units 200 and 201 having the hot water storage tanks 210 and 211 having the smallest amount of hot water storage, respectively. As such, the fuel cell units 100 to 102 may be controlled. When there are a plurality of hot water storage units having the smallest amount of hot water storage, it is possible to improve the convenience for the user by generating hot water of the hot water storage unit having a relatively high temperature.

  In addition, when there are a plurality of hot water storage units having the smallest amount of hot water storage, the control unit 150 may control the fuel cell units 100 to 102 so as to generate hot water of the hot water storage units that are relatively frequently used. For example, in the fuel cell system 1 shown in FIG. 1, the amount of hot water stored in the hot water storage tanks 210 and 211 is the smallest, and the hot water usage frequency of the hot water storage tank 210 is relatively high. In this case, the control unit 150 generates the hot water of the hot water storage unit 200 that is relatively frequently used in the hot water storage units 200 and 201 having the hot water storage tanks 210 and 211 having the smallest amount of hot water storage, respectively. -102 may be controlled. When there are a plurality of hot water storage units having the smallest amount of hot water storage, it is possible to improve the convenience for the user by generating hot water of the hot water storage units that are relatively frequently used.

  Hereinafter, an example of the operation of the fuel cell system 1 according to an embodiment of the present invention will be described.

[System operation]
FIG. 2 is a flowchart showing an example of the operation of the fuel cell system 1 according to one embodiment of the present invention. In the following, it is assumed that the amount of hot water stored in the hot water storage tank 211 is the smallest because the customer facility 500 uses hot water of 60 ° C.

  First, the control unit 150 of the fuel cell unit 100 that is the parent device detects the hot water storage tank 211 with the smallest amount of hot water storage when the power consumption of the customer facility 500 increases and the power generation of the fuel cell units 100 to 102 is required. (Step S101). Next, in the fuel cell units 100 to 102, the control unit 150 sets so as to generate hot water having a set temperature of 60 ° C. in the hot water storage tank 211 having the smallest amount of hot water storage (step S102). For example, the control unit 150 sets the temperature of hot water generated by the own device (fuel cell unit 100) to 60 ° C., which is the set temperature of the hot water storage tank 211 having the smallest amount of stored hot water. In addition, the control unit 150 instructs the fuel cell units 101 and 102 as child devices to generate hot water having a set temperature of 60 ° C. in the hot water storage tank 211 having the smallest amount of hot water storage and generate power.

  Thereafter, the fuel cell unit 100 that is the parent device starts power generation, and the fuel cell units 101 and 102 that are the child devices also start power generation when receiving the instruction in the process of step S102 (step S103). Thereby, in the fuel cell units 100 to 102, power generation is performed, and exhaust heat generated by the power generation is recovered to generate hot water of 60 ° C.

  Then, the control part 150 controls the transfer means 300 so that the hot water produced | generated by the fuel cell units 100-102 may be transferred to the hot water storage tank 211 with the least amount of hot water storage (step S104). Based on this control, hot water is transferred by the transfer means 300 to the hot water storage tank 211 having the smallest amount of hot water storage.

  In the process of step S102, the control unit 150 controls all the fuel cell units 100 to 102 to generate power together, but the fuel cell units 100 to 102 have the same power generation time. The battery units 100 to 102 may be generated in order.

  Further, in the process of steps S101 to S104, the 60 ° C. hot water generated in the fuel cell units 100 to 102 is transferred until the hot water storage tank 211 having the smallest amount of hot water detected in the process of step S101 is full. It may be. Alternatively, while the fuel cell units 100 to 102 are generating electric power, the control unit 150 periodically detects the hot water storage tank with the smallest amount of hot water storage, and uses hot water at a temperature set in the detected hot water storage tank as fuel. You may generate electric power by producing | generating with the battery units 100-102. At this time, the generated hot water is controlled to be transferred to the hot water storage tank with the smallest amount of hot water detected by the transfer means 300 periodically.

  In the present embodiment, the example in which the control unit 150 of the fuel cell unit 100 that is the parent apparatus executes the control according to the embodiment of the present invention has been described, but the present invention is not limited to this. For example, instead of the control unit 150 of the fuel cell unit 100 that is the parent device, an EMS (Energy Management System), a control unit of a remote server, or the like may execute the control according to the embodiment of the present invention.

  As described above, in the fuel cell system 1 according to one embodiment of the present invention, hot water having a temperature set in the hot water storage tank 211 having the smallest amount of hot water is generated, and the generated hot water is stored in the hot water storage tank having the smallest amount of hot water. 211 is transferred. Thereby, for example, even if the hot water storage tanks 210 and 212 are full, the fuel cell units 100 and 102 can generate power without throwing away hot water. Therefore, hot water can be efficiently generated using the exhaust heat of the fuel cell units 100 to 102.

  Furthermore, in the fuel cell system 1 according to an embodiment of the present invention, all the fuel cell units 100 to 102 are controlled to generate power together (or the power generation times of the fuel cell units 100 to 102 are equalized). The power generation times in all the fuel cell units 100 to 102 are made equal by generating power in order. Thereby, since the power generation time of the fuel cell units 100 to 102 can be averaged, the progress of deterioration of the fuel cell units 100 to 102 can be made uniform.

  Moreover, in the fuel cell system 1 which concerns on one Embodiment of this invention, the hot water storage tanks 210-212 can be set to a different temperature. Therefore, the hot water which a user desires can be provided promptly.

  The fuel cell system according to the present invention is not limited to the fuel cell system 1 described above. Hereinafter, modifications that can be employed in the fuel cell system according to the present invention will be described.

(Modification 1)
FIG. 3 is a diagram showing an example of the configuration of a fuel cell system 1a according to a modification of the present invention. 3 that are the same as those shown in FIG. 1 are assigned the same reference numerals, and descriptions thereof are omitted.

  The fuel cell system 1 a includes fuel cell units 100, 101, hot water storage units 200, 201, 202, transfer means 301, and transfer means 400. That is, the fuel cell system 1a includes two fuel cell units 100 and 101 and three hot water storage units 200 to 202 (three hot water storage tanks 210 to 212).

  The transfer unit 301 includes, for example, an on-off valve, a pipe, a pump, and the like, and includes on-off valves 311, 321, and 331. The on / off valve 311 is connected between all of the fuel cell units 100 and 101 and the hot water storage tank 210, the on / off valve 321 is connected between all of the fuel cell units 100 and 101 and the hot water storage tank 211, and the on / off valve 331 is It is connected between all of the fuel cell units 100 and 101 and the hot water tank 212. Based on control from the fuel cell unit 100 that is the parent device, the transfer means 301 closes or opens the on-off valves 311 to 331, collects the exhaust heat of the fuel cell units 100 and 101, and generates hot water. Is transferred to hot water tanks 210-212.

  Even in such a fuel cell system 1a in which the number of fuel cell units 100 and 101 is smaller than the number of hot water storage tanks 210 to 212, the same control and effects as the fuel cell system 1 according to the embodiment of the present invention are used. Can be realized.

(Modification 2)
FIG. 4 is a diagram illustrating an example of a configuration of a fuel cell system 1b according to a modification of the present invention. 4 that are the same as those shown in FIG. 1 are assigned the same reference numerals and explanations thereof are omitted.

  The fuel cell system 1 b includes fuel cell units 100, 101, 102, hot water storage units 200, 201, transfer means 302, and transfer means 401. That is, the fuel cell system 1b includes three fuel cell units 100 to 102 and two hot water storage units 200 and 201 (two hot water storage tanks 210 and 211).

  The transfer unit 302 includes, for example, an on-off valve, a pipe, a pump, and the like, and includes on-off valves 312 and 322. The on-off valve 312 is connected between all of the fuel cell units 100 to 102 and the hot water tank 210, and the on / off valve 322 is connected between all of the fuel cell units 100 to 102 and the hot water tank 211. Based on control from the fuel cell unit 100 that is the parent device, the transfer means 302 closes the open / close valves 312 and 322 or opens the hot water generated by recovering the exhaust heat of the fuel cell units 100 to 102. Is transferred to the hot water storage tanks 210 and 211.

  The transfer unit 401 includes, for example, an on-off valve, piping, a pump, and the like, and includes on-off valves 411 and 421. The on-off valve 411 is connected between the hot water storage tank 210 and the customer facility 500, and the on-off valve 421 is connected between the hot water storage tank 211 and the customer facility 500. The transfer means 401 transfers the hot water stored in the hot water storage tanks 210 and 211 to the customer facility 500 by closing the open / close valves 411 and 421 based on the control from the fuel cell unit 100 as the parent device. To do.

  Even in the fuel cell system 1b in which the number of the fuel cell units 100 to 102 is larger than the number of the hot water storage tanks 210 and 211, the same control and effect as the fuel cell system 1 according to the embodiment of the present invention. Can be realized.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each component, each step, etc. can be rearranged so that there is no logical contradiction, and multiple components, steps, etc. can be combined or divided into one It is. Further, although the present invention has been described mainly with respect to the apparatus, the present invention can also be realized as a method, a program executed by a processor included in the apparatus, or a storage medium storing the program, and is within the scope of the present invention. It should be understood that these are also included.

1, 1a, 1b Fuel cell system 100, 101, 102 Fuel cell unit 110 Fuel reforming unit 120 Fuel cell stack 130 Inverter 140 Waste heat recovery unit 150 Control unit 160 Storage unit 170 Communication unit 200, 201, 202 Hot water storage unit 210, 211,212 Hot water storage tank 220,221,222 Backup heat source machine 300,301,302,400,401 Transfer means 310,311,312,320,321,322,330,331,410,411,420,421,430 Open / close Valve 500 Customer facility

Claims (7)

A fuel cell system including a fuel cell unit and a plurality of hot water storage units,
A transfer means configured to transfer hot water generated by recovering exhaust heat of the fuel cell unit to the plurality of hot water storage units;
A fuel cell system comprising: a controller for controlling the transfer means to transfer hot water to a hot water storage unit having the smallest amount of hot water storage among the plurality of hot water storage units. Each of the plurality of hot water storage units is configured to store hot water having different temperatures,
2. The fuel cell system according to claim 1, wherein the control unit controls each of the fuel cell units to generate hot water having a temperature set by the hot water storage unit having the smallest amount of hot water storage. A fuel cell unit,
The fuel cell unit is connected to transfer means configured to be able to transfer hot water generated by recovering the exhaust heat of the fuel cell unit to the hot water storage unit,
A fuel cell unit comprising a controller that controls the transfer means to transfer hot water to the hot water storage unit having the smallest amount of hot water storage among the plurality of hot water storage units. A fuel cell unit operation control method in a fuel cell system including a fuel cell unit and a plurality of hot water storage units, wherein the fuel cell system collects hot water generated by recovering exhaust heat of the fuel cell unit. A transfer means configured to be transferable to the hot water storage unit of
Detecting the hot water storage unit having the smallest amount of hot water storage;
A first control step for controlling the transfer means to transfer the hot water generated by the fuel cell unit to the hot water storage unit having the least amount of hot water;
An operation control method for the fuel cell unit, comprising: Each of the plurality of hot water storage units is configured to store hot water having different temperatures,
The first control step includes
5. The operation of the fuel cell unit according to claim 4, further comprising a second control step of controlling the fuel cell unit to generate hot water having a temperature set in the hot water storage unit having the smallest amount of hot water storage. Control method. And a third control step of controlling the fuel cell unit so as to generate hot water of the hot water storage unit having a relatively high temperature when there are a plurality of the hot water storage units having the smallest hot water storage amount. The operation control method of the fuel cell unit according to claim 4. 4. The fourth control step of controlling the fuel cell unit so as to generate hot water of a hot water storage unit that is relatively frequently used when there are a plurality of hot water storage units having the smallest hot water storage amount. 5. An operation control method for a fuel cell unit according to 4.

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