Fuel cell unit and fuel cell system

Abstract

This fuel cell unit is provided with a plurality of fuel cell stacks, a cooling water path, a supply device, a plurality of regulating valves, a first measuring device, and a control device. The cooling water path is a path through which cooling water for cooling the plurality of fuel cell stacks circulates. The supply device is a device that supplies the cooling water to the plurality of fuel cell stacks. The plurality of regulating valves regulate the supply flow rate of the cooling water to each of the plurality of fuel cell stacks. The first measuring device measures the temperature of the cooling water discharged from each of the plurality of fuel cell stacks. The control device controls the supply device and the plurality of regulating valves to regulate the flow rate of the cooling water according to the temperature of the cooling water measured by the first measuring device.

Description

Fuel cell unit and fuel cell system

[0001] This disclosure relates to fuel cell units and fuel cell systems.

[0002] Patent Document 1 describes a cooling water circulation supply system for a fuel cell. This cooling water circulation supply system has a circulation path for circulating cooling water to a fuel cell. The cooling water circulation supply system includes a cooling water circulation pump, a cooler, and a temperature control device in the circulation path. The cooling water circulation pump is a pump that circulates the cooling water. The cooler cools the cooling water. The temperature control device adjusts the temperature of the cooling water supplied to the fuel cell by increasing or decreasing the amount of cooling water distributed to the cooler.

[0003] Japanese Patent Publication No. 2004-14484

[0004] Conventional technology deserves re-examination from the perspective of reducing power consumption and manufacturing costs of fuel cell units equipped with multiple fuel cell stacks.

[0005] The fuel cell unit in this disclosure comprises: a plurality of fuel cell stacks; a cooling water path through which cooling water circulates for cooling the plurality of fuel cell stacks; a supply unit for supplying the cooling water to the plurality of fuel cell stacks; a plurality of control valves for adjusting the flow rate of the cooling water supplied to each of the plurality of fuel cell stacks; a first measuring instrument for measuring the temperature of the cooling water discharged from each of the plurality of fuel cell stacks; and a controller for controlling the supply unit and the plurality of control valves to adjust the flow rate of the cooling water supplied according to the temperature of the cooling water measured by the measuring instrument.

[0006] According to this disclosure, it is possible to reduce the power consumption and manufacturing costs of a fuel cell unit equipped with multiple fuel cell stacks.

[0007] Configuration diagram of the fuel cell unit in Embodiment 1 Flowchart showing an example of control of the fuel cell unit in Embodiment 1 Flowchart showing another example of control of the fuel cell unit in Embodiment 1 Flowchart showing yet another example of control of the fuel cell unit in Embodiment 1 Flowchart showing yet another example of control of the fuel cell unit in Embodiment 1 Timing chart showing the control period in the fuel cell unit in Embodiment 1 Configuration diagram of the fuel cell system in Embodiment 2 Flowchart showing an example of control of the fuel cell system in Embodiment 2

[0008] (Knowledge and other information forming the basis of this disclosure) At the time the inventors conceived of this disclosure, it was known that cooling water was circulated to cool fuel cell stacks. In order to increase the output of a fuel cell unit, it is conceivable to configure the fuel cell unit to include multiple fuel cell stacks. In this case, it is considered necessary to supply cooling water to each of the multiple fuel cell stacks in the fuel cell unit and circulate the cooling water.

[0009] It is conceivable to place multiple pumps or other supply devices in the fuel cell unit to provide cooling water to each of the multiple fuel cell stacks. However, such a fuel cell unit tends to consume a lot of power, or its manufacturing cost tends to be high.

[0010] The inventors of this invention have focused on a configuration for supplying cooling water to multiple fuel cell stacks in a fuel cell unit equipped with multiple fuel cell stacks, from the viewpoint of reducing power consumption and manufacturing costs, and have come to form the subject of this disclosure.

[0011] This disclosure provides a fuel cell unit and a fuel cell system that can reduce power consumption and manufacturing costs of a fuel cell unit equipped with multiple fuel cell stacks.

[0012] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art.

[0013] The attached drawings and the following description are provided to help the parties fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0014] (Embodiment 1) Embodiment 1 will be described below with reference to Figures 1 to 6.

[0015] [1-1. Configuration] Figure 1 is a configuration diagram of the fuel cell unit in Embodiment 1. As shown in Figure 1, the fuel cell unit 1a comprises a plurality of fuel cell stacks 10, a cooling water path 11, a supply unit 12, a plurality of control valves 13, a first measuring instrument 14, and a controller 15. The cooling water path 11 is a path through which cooling water circulates to cool the plurality of fuel cell stacks 10. The supply unit 12 is a device that supplies cooling water to the plurality of fuel cell stacks 10. The plurality of control valves 13 adjust the flow rate of cooling water supplied to each of the plurality of fuel cell stacks 10. The first measuring instrument 14 measures the temperature of the cooling water discharged from each of the plurality of fuel cell stacks 10. The controller 15 controls the supply unit 12 and the plurality of control valves 13 to adjust the flow rate of the cooling water according to the temperature of the cooling water measured by the first measuring instrument 14.

[0016] Each of the multiple fuel cell stacks 10 comprises, for example, an electrolyte membrane, an anode, and a cathode. The electrolyte membrane is positioned between the anode and the cathode. The anode and cathode are each provided with a catalyst for extracting electrons and hydrogen ions from hydrogen molecules, and a catalyst for generating water from electrons, hydrogen ions, and oxygen ions. A hydrogen-containing gas supply path is connected to the anode. An oxygen-containing gas supply path is connected to the cathode. Hydrogen-containing gas is supplied to the anode from a hydrogen-containing gas source through the hydrogen-containing gas supply path. Oxygen-containing gas is supplied to the cathode from an oxygen-containing gas source through the oxygen-containing gas supply path.

[0017] The hydrogen-containing gas may be pure hydrogen gas, or it may be a gas obtained by steam reforming, partial oxidation reaction, autothermal reaction, etc. Examples of hydrogen-containing gas sources include hydrogen storage tanks, other hydrogen gas infrastructure, and reformers. The oxygen-containing gas is, for example, air. An example of an oxygen-containing gas source is an air blower. Other equipment, such as flow control valves, is installed in the hydrogen-containing gas supply route and the oxygen-containing gas supply route.

[0018] Each of the multiple fuel cell stacks 10 is, for example, a polymer electrolyte fuel cell (PEFC). Each of the multiple fuel cell stacks 10 may also be other types of fuel cells, such as direct methanol fuel cells (DMFCs) and alkaline fuel cells (AFCs).

[0019] The number of fuel cell stacks 10 included in the fuel cell unit 1a is not limited to a specific value, as long as it is two or more. The number of fuel cell stacks 10 included in the fuel cell unit 1a may be three or more, four or more, or five or more, and for example, it may be 10 or less. In the fuel cell unit 1a, the multiple fuel cell stacks 10 are connected electrically in series, for example.

[0020] As shown in Figure 1, a supply unit 12 is located in the cooling water path 11. An example of a supply unit 12 is a pump.

[0021] As shown in FIG. 1, the cooling water path 11 includes, for example, a branch point 11j and a confluence point 11k. The cooling water path 11 includes a plurality of flow paths 11b arranged in parallel between the branch point 11j and the confluence point 11k. Each of the plurality of flow paths 11b extends through any one of the plurality of fuel cell stacks 10.

[0022] The plurality of control valves 13 are each provided in the plurality of flow paths 11b. The control valve 13 is arranged, for example, between the branch point 11j and the fuel cell stack 10.

[0023] The first measuring device 14 includes, for example, a plurality of first measuring devices 14. The plurality of first measuring devices 14 are each provided in the plurality of flow paths 11b. The first measuring device 14 is arranged between the fuel cell stack 10 and the confluence point 11k. The first measuring device 14 is, for example, a contact-type temperature sensor, and includes a thermocouple, a platinum resistance temperature detector, a thermistor, or the like.

[0024] As shown in FIG. 1, the fuel cell unit 1a further includes, for example, a tank 11t. The tank 11t is arranged, for example, between the confluence point 11k and the supplier 12 in the cooling water path 11. The cooling water that has passed through the plurality of flow paths 11b is collected and stored in the tank 11t. The cooling water stored in the tank 11t is supplied toward the plurality of fuel cell stacks 10 by the supplier 12.

[0025] As described above, the controller 15 controls the supplier 12 and the plurality of control valves 13. The controller 15 is, for example, a DSP (Digital Signal Processor) including an arithmetic circuit, a storage circuit, and the like. A CPU can be cited as an example of the arithmetic circuit. A memory can be cited as an example of the storage circuit. A control program for the fuel cell unit 1a and a fuel cell system including the fuel cell unit 1a is stored in the storage circuit.

[0026] [1-2. Operation] The operation and effect of the fuel cell unit 1a configured as described above will be described below.

[0027] Fig. 2 is a flowchart showing an example of control of the fuel cell unit according to Embodiment 1. When the fuel cell unit 1a is generating power, the feeder 12 operates to circulate cooling water through a cooling water path, thereby cooling the plurality of fuel cell stacks 10. As shown in Fig. 2, when a predetermined condition is satisfied, the controller 15 obtains the measurement value V of the first measuring device 14 in step S11 14 . Next, proceeding to step S12, the controller 15 calculates the average temperature T based on the measurement value V of the first measuring device 14 14 14A . The average temperature T 14A is the average temperature of cooling water discharged from the plurality of fuel cell stacks 10. The average temperature T 14A is calculated, for example, as the arithmetic average of the measurement values V of the plurality of first measuring devices 14 14 .

[0028] Next, proceeding to step S13, the manipulated variable M of the feeder 12 is determined based on the average temperature T 14A and the target temperature T tA 12 . The manipulated variable M 12 is determined such that the average temperature of cooling water discharged from the plurality of fuel cell stacks 10 approaches the target temperature T tA . Next, proceeding to step S14, the controller 15 controls the feeder 12 in accordance with the manipulated variable M 12 and ends the control of the feeder 12. For example, a control signal is sent from the controller 15 to the feeder 12, the rotation speed of the motor of the pump that serves as the feeder 12 is adjusted in accordance with the manipulated variable M 12 , and the flow rate of cooling water supplied by the feeder 12 is adjusted. In this way, the controller 15 controls the feeder 12 and adjusts the flow rate of cooling water supplied by the feeder 12, thereby bringing the average temperature of cooling water discharged from the plurality of fuel cell stacks 10 closer to the target temperature T tA . The series of processes shown in Fig. 2 is performed periodically, for example, when the fuel cell unit 1a is generating power.

[0029] ​​Figure 3 is a flowchart showing another example of control of the fuel cell unit in Embodiment 1. As shown in Figure 3, when a predetermined condition is met while the fuel cell unit 1a is generating power, the controller 15, in step S21, measures the measured value V of the first measuring instrument 14. 14 Next, the process proceeds to step S22, where the controller 15 obtains the measured value V of the first measuring instrument 14. 14 Based on the average temperature T 14A Calculate the average temperature T. 14A This is the average temperature of the cooling water discharged from multiple fuel cell stacks 10. 14A For example, the measured values ​​V of multiple first measuring instruments 14. 14 It is calculated as the arithmetic mean of [the given values].

[0030] Next, proceed to step S23, and measure the value V 14 and average temperature T 14A Based on this, the opening degree VT of the multiple control valves 13 13 The opening degree VT of the multiple control valves 13 is determined. 13 The temperature of the cooling water discharged from each of the multiple fuel cell stacks 10 is the average temperature T. 14A It is determined to approach this. Opening angle VT 13 This is determined for each of the multiple control valves 13. Next, the process proceeds to step S24, where the controller 15 controls the opening degree VT 13 The control valves 13 are controlled accordingly, and the control of the control valves 13 is terminated. For example, a control signal is sent from the controller 15 to the control valves 13, and the opening degree VT of each of the control valves 13 is controlled. 13 The opening degrees of the multiple control valves 13 are adjusted accordingly. In this way, the controller 15 adjusts the opening degrees of the multiple control valves 13 to bring the temperature of the cooling water discharged from each of the multiple fuel cell stacks 10 closer to the average temperature of the cooling water discharged from the multiple fuel cell stacks 10. The series of processes shown in Figure 3 are performed periodically, for example, when the fuel cell unit 1a is generating power.

[0031] Figure 4 is a flowchart showing yet another example of the control of the fuel cell unit in Embodiment 1. For example, the controller 15 obtains the current values ​​of the multiple fuel cell stacks 10. Next, in step S32, the controller 15 sets a target value VT of the average value of the opening degrees of the multiple control valves 13 based on these current values. 13A Determine the target value VT. 13A In determining this, the generated voltage in the multiple fuel cell stacks 10, the theoretical generated voltage in the multiple fuel cell stacks 10, and the number of cells in the fuel cell stacks 10 may also be taken into consideration. For example, as this current value increases, the target value VT 13A It is also determined to increase. Next, the process proceeds to step S33, where the controller 15 sets the target value VT 13A The controller controls the multiple control valves 13 accordingly, and then terminates the control of the multiple control valves 13. For example, a control signal is sent from the controller 15, and the opening degree of the multiple control valves 13 is adjusted. In this way, the controller 15 adjusts the average value of the opening degrees of the multiple control valves 13 according to the current values ​​of the multiple fuel cell stacks 10.

[0032] Figure 5 is a flowchart showing yet another example of the control of the fuel cell unit in Embodiment 1. As shown in Figure 5, in step S41, the controller 15 acquires data on the rotational speed MV of the feeder 12. Next, the process proceeds to step S42, when the rotational speed MV is a predetermined value MV t It is determined whether it is greater or less. If the result of the determination in step S42 is positive, the process proceeds to step S43, and the opening degree VT of the multiple control valves 13 is adjusted so that the pressure loss of the control valves 13 decreases. 13 This is adjusted. As a result, the rotational speed MV of the feeder 12 decreases. On the other hand, if the judgment result in step S42 is negative, the process proceeds to step S44 and the opening degree VT of the multiple control valves 13 is adjusted. 13 It will be adjusted as usual.

[0033] The control of the supply unit 12 and the plurality of control valves 13 is performed, for example, at a predetermined period. Figure 6 is a timing chart showing the control period in the fuel cell unit in Embodiment 1. As shown in Figure 6, the controller 15 controls, for example, the plurality of control valves 13 in a first period P1 and the supply unit 12 in a second period P2. The first period P1 is, for example, longer than the second period P2.

[0034] (Embodiment 2) Embodiment 2 will be described below with reference to Figures 7 and 8.

[0035] [2-1. Configuration] Figure 7 is a configuration diagram of the fuel cell system 2a in Embodiment 2. As shown in Figure 7, the fuel cell system 2a comprises the fuel cell unit 1a in Embodiment 1, a heat recovery path 20, a circulator 21, and a flow rate regulator 22. The heat recovery path 20 is a path through which a heat transfer medium flows that exchanges heat with the cooling water supplied to the fuel cell stack 10 of the fuel cell unit 1a. The heat recovery path 20 includes a flow path 20b that extends inside the fuel cell unit 1a. The circulator 21 is provided on the heat recovery path 20 and circulates the heat transfer medium. The circulator 21 is, for example, a pump. The circulator 21 is, for example, located outside the fuel cell unit 1a. The flow rate regulator 22 is a device that adjusts the supply flow rate of the heat transfer medium. The flow rate regulator 22 is, for example, a control valve. The heat transfer medium is, for example, water.

[0036] As shown in Figure 7, the fuel cell unit 1a further includes a heat exchanger 30. The heat exchanger 30 is provided, for example, in the cooling water path 11 between the confluence point 11k and the tank 11t. The heat exchanger 30 includes part of the cooling water path 11 and part of the heat recovery path 20, and heat exchange between the cooling water and the heat transfer medium takes place in the heat exchanger 30. The heat exchanger 30 is a liquid-liquid heat exchanger such as a double-tube heat exchanger, a shell-and-tube heat exchanger, or a plate heat exchanger. The heat exchanger 30 is configured, for example, so that the flow of cooling water and the flow of the heat transfer medium are in counterflow. The heat recovery path 20 may be provided with another heat exchanger for exchanging heat between gas or air and the heat transfer medium.

[0037] The flow regulator 22 is located, for example, inside the fuel cell unit 1a and is positioned downstream of the heat exchanger 30 in the heat recovery path 20.

[0038] The fuel cell system 2a further includes, for example, a heat utilization device 50. A heat recovery path 20 is connected to the heat utilization device 50. The heat transfer medium, delivered by the circulator 21, recovers heat from the cooling water by passing through the heat exchanger 30, and the heat transfer medium that has passed through the heat exchanger 30 is supplied to the heat utilization device 50. In this way, the heat recovered by the heat transfer medium is utilized in the heat utilization device 50. The heat utilization device 50 is, for example, equipment for hot water supply, heating, or other heat utilization processes.

[0039] As shown in Figure 7, the fuel cell system 2a comprises, for example, a plurality of fuel cell units 1a. The heat recovery path 20 includes a plurality of branching channels 20b. Each of the channels 20b extends inside one of the plurality of fuel cell units 1a. The channels 20b are arranged in parallel.

[0040] The fuel cell unit 1a further includes, for example, a second measuring instrument 18. The second measuring instrument 18 measures the temperature of the cooling water supplied to the fuel cell stack 10. The second measuring instrument 18 measures, for example, the temperature of the cooling water flowing between the heat exchanger 30 and the branching point 11j in the cooling water path 11. The second measuring instrument 18 is, for example, a contact-type temperature sensor and includes a thermocouple, a platinum resistance thermometer, or a thermistor.

[0041] The number of fuel cell units 1a included in the fuel cell system 2a is not limited to a specific value. The number of fuel cell units 1a included in the fuel cell system 2a may be 1, or it may be 2 to 9 or 11 or more.

[0042] [2-2. Operation] The operation and function of the fuel cell system 2a configured as described above will be explained below.

[0043] When the fuel cell unit 1a is generating power, cooling water circulates in the cooling water path 11, cooling the multiple fuel cell stacks 10. The cooling water, having received heat by passing through the fuel cell stacks 10, is supplied to the heat exchanger 30 by the supply unit 12. The cooling water is cooled by passing through the heat exchanger 30. After that, the cooling water is supplied back to the fuel cell stacks 10. When the fuel cell unit 1a is generating power, the circulator 21 operates, and the heat transfer medium flows through the heat recovery path 20. The heat transfer medium recovers heat from the cooling water by passing through the heat exchanger 30. After that, the heat transfer medium is supplied to the heat utilization equipment 50 via the heat recovery path 20, and the heat recovered by the heat transfer medium is utilized in the heat utilization equipment 50.

[0044] Figure 8 is a flowchart showing an example of control of the fuel cell system in Embodiment 2. As shown in Figure 8, when the fuel cell system 2a is generating power and a predetermined condition is met, in step S51, the controller 15 measures the measured value V of the second measuring instrument 18. 18 Next, the process proceeds to step S52, where the controller 15 obtains the measured value V. 18 Based on this, the operating amount M of the flow regulator 22 22 Determine the manipulated variable M. 22 For example, the temperature of the cooling water supplied to the fuel cell stack 10 is determined to approach the target temperature. Next, the process proceeds to step S53, where the controller 15 controls the manipulated variable M 22 The flow regulator 22 is controlled accordingly. For example, a control signal is sent from the controller 15 to the flow regulator 22, and the manipulated amount M 22 Accordingly, the opening degree of the control valve, which is the flow regulator 22, is adjusted. In this way, the controller controls the flow regulator 22 to adjust the supply flow rate of the heat transfer medium, thereby bringing the temperature of the cooling water supplied to the fuel cell stack 10 closer to the target temperature.

[0045] (Other Embodiments) As described above, Embodiments 1 and 2 have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these and can be applied to embodiments that have been modified, replaced, added, omitted, etc. Furthermore, it is possible to create new embodiments by combining the components described in the above embodiments.

[0046] Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the scope of the claims or equivalents thereof.

[0047] (Note) The above description of embodiments discloses the following technology.

[0048] (Technology 1) A fuel cell unit comprising: a plurality of fuel cell stacks; a cooling water path through which cooling water circulates for cooling the plurality of fuel cell stacks; a supply unit for supplying the cooling water to the plurality of fuel cell stacks; a plurality of control valves for adjusting the flow rate of the cooling water supplied to each of the plurality of fuel cell stacks; a first measuring instrument for measuring the temperature of the cooling water discharged from each of the plurality of fuel cell stacks; and a controller for controlling the supply unit and the plurality of control valves to adjust the flow rate of the cooling water supplied according to the temperature of the cooling water measured by the measuring instrument.

[0049] According to the fuel cell unit of Technology 1, although it has multiple fuel cell stacks, it is equipped with multiple control valves that adjust the flow rate of cooling water supplied to each of the multiple fuel cell stacks, so that the flow rate of cooling water can be adjusted with a single supply. As a result, the power consumption of the fuel cell unit and the manufacturing cost of the fuel cell unit can be reduced.

[0050] (Technology 2) The fuel cell unit according to Technology 1, wherein the controller controls the supplyer and adjusts the flow rate of the cooling water supplied by the supplyer, thereby bringing the average temperature of the cooling water discharged from the plurality of fuel cell stacks closer to a target temperature.

[0051] According to the fuel cell unit of Technology 2, although it has multiple fuel cell stacks, the flow rate of the cooling water can be adjusted with a single supply. Therefore, the power consumption of the fuel cell unit and the manufacturing cost of the fuel cell unit can be reduced.

[0052] (Technology 3) The fuel cell unit according to Technology 1 or 2, wherein the controller adjusts the opening degree of the plurality of control valves to bring the temperature of the cooling water discharged from each of the plurality of fuel cell stacks closer to the average temperature of the cooling water discharged from the plurality of fuel cell stacks.

[0053] According to the fuel cell unit of Technology 3, although it has multiple fuel cell stacks, the flow rate of the cooling water can be adjusted with a single supply. Therefore, the power consumption of the fuel cell unit and the manufacturing cost of the fuel cell unit can be reduced.

[0054] (Technology 4) The fuel cell unit according to any one of Technology 1 to 3, wherein the controller adjusts the average value of the opening degrees of the plurality of control valves according to the current values ​​of the plurality of fuel cell stacks.

[0055] According to the fuel cell unit of Technology 4, the accuracy of adjusting the cooling water temperature by the control valve tends to be higher.

[0056] (Technical 5) The fuel cell unit according to any one of Technical 1 to 4, wherein the controller reduces the rotational speed of the supply unit by adjusting the opening of the plurality of control valves so as to reduce the pressure loss of the control valves when the rotational speed of the supply unit exceeds a predetermined value.

[0057] According to the fuel cell unit of Technology 5, the pressure loss in the cooling water path is easily reduced, and the rotation speed of the water supply does not easily increase. Therefore, the power consumption of the fuel cell unit is more easily reduced.

[0058] (Technical 6) The fuel cell unit according to any one of Technical 1 to 5, wherein the controller controls the plurality of control valves in a first cycle and controls the supply unit in a second cycle, and the first cycle is longer than the second cycle.

[0059] According to the fuel cell unit of Technology 6, the control valve is controlled with a longer period than the control cycle of the supply unit, which makes it easier to suppress an increase in the power consumption of the fuel cell unit, and prevents deterioration such as wear of the control valve components over a long period of time. In addition, it is possible to prevent temperature instability caused by interference between the control of the supply unit and the control valve.

[0060] (Technical 7) A fuel cell system comprising: a fuel cell unit according to any one of Technical 1 to 6; a heat recovery path through which a heat transfer medium that exchanges heat with the cooling water flows; a circulator provided on the heat recovery path for circulating the heat transfer medium; and a flow regulator provided on the heat recovery path for adjusting the supply flow rate of the heat transfer medium.

[0061] According to the fuel cell system of Technology 7, for example, even when multiple fuel cell units are provided, the heat transfer medium can be supplied by a single circulator. This reduces the power consumption of the fuel cell system and the manufacturing cost of the fuel cell system.

[0062] (Technical 8) The fuel cell system according to Technical 7, further comprising a second measuring instrument for measuring the temperature of the cooling water supplied to the fuel cell stack, wherein the controller controls the flow rate regulator to adjust the supply flow rate of the heat transfer medium, thereby bringing the temperature of the cooling water supplied to the fuel cell stack closer to a target temperature.

[0063] According to the fuel cell system of Technology 8, for example, even when multiple fuel cell units are provided, the flow rate of the heat transfer medium can be adjusted with a single circulator. This reduces the power consumption of the fuel cell system and the manufacturing cost of the fuel cell system.

[0064] The technology disclosed herein is applicable to fuel cell units equipped with multiple fuel cell stacks, and is also applicable to power generation systems that supply electricity by linking solar power generation facilities, fuel cell facilities, battery storage facilities, and commercial power sources. The technology disclosed herein is also applicable to environmental protection initiatives such as RE100 (Renewable Energy 100%).

Claims

1. A fuel cell unit comprising: a plurality of fuel cell stacks; a cooling water path through which cooling water circulates for cooling the plurality of fuel cell stacks; a supply unit for supplying the cooling water to the plurality of fuel cell stacks; a plurality of control valves for adjusting the flow rate of the cooling water supplied to each of the plurality of fuel cell stacks; a first measuring instrument for measuring the temperature of the cooling water discharged from each of the plurality of fuel cell stacks; and a controller for controlling the supply unit and the plurality of control valves to adjust the flow rate of the cooling water according to the temperature of the cooling water measured by the first measuring instrument.

2. The fuel cell unit according to claim 1, wherein the controller controls the supplyer and adjusts the flow rate of the cooling water supplied by the supplyer, thereby bringing the average temperature of the cooling water discharged from the plurality of fuel cell stacks closer to a target temperature.

3. The fuel cell unit according to claim 1, wherein the controller adjusts the opening degree of the plurality of control valves to bring the temperature of the cooling water discharged from each of the plurality of fuel cell stacks closer to the average temperature of the cooling water discharged from the plurality of fuel cell stacks.

4. The fuel cell unit according to claim 1, wherein the controller adjusts the average value of the opening degrees of the plurality of control valves according to the current values ​​of the plurality of fuel cell stacks.

5. The fuel cell unit according to claim 1, wherein the controller reduces the rotational speed of the supply unit by adjusting the opening of the plurality of control valves so as to reduce the pressure loss of the control valves when the rotational speed of the supply unit exceeds a predetermined value.

6. The fuel cell unit according to claim 1, wherein the controller controls the plurality of control valves in a first cycle and controls the supply unit in a second cycle, and the first cycle is longer than the second cycle.

7. A fuel cell system comprising: a fuel cell unit according to any one of claims 1 to 6; a heat recovery path through which a heat transfer medium that exchanges heat with the cooling water flows; a circulator provided on the heat recovery path for circulating the heat transfer medium; and a flow regulator provided on the heat recovery path for adjusting the supply flow rate of the heat transfer medium.

8. The fuel cell system according to claim 7, comprising a second measuring instrument for measuring the temperature of the cooling water supplied to the fuel cell stack, wherein the controller controls the flow rate regulator to adjust the supply flow rate of the heat transfer medium, thereby bringing the temperature of the cooling water supplied to the fuel cell stack closer to a target temperature.

Images