JP5750570B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system including a circulation pump and a supply pump.

  A polymer electrolyte fuel cell (hereinafter abbreviated as “fuel cell”) using a polymer electrolyte membrane as an electrolyte is incorporated in a fuel cell system. This fuel cell generates electricity by an electrochemical reaction that is an exothermic reaction between hydrogen in fuel gas containing hydrogen gas as a main component and oxygen in air. The fuel gas is obtained, for example, by steam reforming a hydrocarbon gas such as city gas.

  In the power generation of the fuel cell, the above-described electrochemical reaction (exothermic reaction) proceeds, so that the operating temperature during power generation of the fuel cell is maintained at a temperature suitable for the reaction (for example, about 70 ° C. to 80 ° C.). Thus, a mechanism for keeping the internal temperature of the fuel cell constant is generally employed.

  For example, a cooling water path through which cooling water flows is arranged in the fuel cell, and the internal temperature of the fuel cell is adjusted by controlling the flow rate of the cooling water flowing through the path. On the other hand, when the heat medium recovers the heat of the high-temperature cooling water that has passed through the fuel cell by heat exchange, and such a heat medium is stored in the heat accumulator, the heat can be stored in the fuel cell system.

  FIG. 5 shows an exhaust heat recovery device mounted on a fuel cell system disclosed in Patent Document 1. As shown in FIG.

  In FIG. 5, the cooling water in the stack cooling water tank 103 is circulated again from the fuel cell stack 102 through the heat exchanger 108 to the stack cooling water tank 103 by the stack circulation pump 104.

  Further, hydrogen discharged from the hydrogen production apparatus 101 passes through the heat exchanger 109, passes through the anode electrode of the fuel cell stack 102, undergoes an electrochemical reaction (exothermic reaction), passes through the heat exchanger 106, and is discharged outside the apparatus.

  On the other hand, the exhaust heat recovery water is conveyed to the heat exchanger 108 by the exhaust heat recovery water pump 105. The amount of heat generated by the power generation in the fuel cell stack 102 is heat-exchanged by the heat exchanger 108 and is recovered as hot water in a hot water storage tank (not shown).

Japanese Patent Laid-Open No. 2005-100903

  However, in the conventional configuration, it is necessary to use a non-self-contained centrifugal pump for the stack circulation pump 104 or the exhaust heat recovery water pump 105.

  This is because the stack circulation pump 104 circulates the cooling water so that the operating temperature during power generation of the fuel cell is maintained at a temperature suitable for the reaction. This amount of circulation needs to be controlled to a very small amount, and must be continuously operated during the operation time of the fuel cell system. For this purpose, the non-self-contained centrifugal pump having high durability is selected in consideration of cost.

  However, at the initial stage of operation, the non-self-contained centrifugal pump supplies the supply water to the stack cooling water tank 103 using the stack circulation pump 104, and further supplies the cooling water supplied to the stack cooling water tank 103 to the stack cooling water tank 103. When the fuel cell 102 is circulated using the cooling water circulation pump 104 to cool the fuel cell 102, there is a possibility that air trapping may occur in the stack circulation pump 104 or the exhaust heat recovery water pump 105.

  In other words, the air biting of the stack circulation pump 104 takes time to supply water to the stack cooling water tank 103, and the test run time of the equipment becomes long, and the air biting of the stack cooling water tank 103 has sufficient cooling water in the cooling water circuit. It was not possible to circulate, and there was a problem that power generation efficiency was reduced due to insufficient cooling of the fuel cell.

  In addition, there is a complex problem that cavitation occurs inside the stack circulation pump 104 or the exhaust heat recovery water pump 105 due to bubbles generated in the pump due to air biting, leading to a reduction in pump life.

  In consideration of the above problems, the present invention shortens the initial water filling time for a cooling circuit used in a fuel cell system and the like, and thus shortens the power generation start time, and prevents air from being caught in the cooling circuit. An object is to provide a fuel cell system that is easy to use and excellent in durability.

  In order to solve the conventional problems, the fuel cell system of the present invention performs initial water filling by directly supplying water to the makeup water supply circuit using direct water pressure. As a result, it is possible to fill the makeup water supply circuit and the supply pump directly with makeup water, and to achieve initial water filling without air biting and cavitation. As a result, filling of the cooling water tank with the supplementary water can be completed without waiting for the filling time of the water supply tank, and the initial filling time of the supplementary water can be shortened.

  The fuel cell of the present invention performs initial water filling by directly supplying water to the cooling water circulation circuit using direct water pressure. Thereby, it is possible to fill the cooling water circulation circuit and the cooling water circulation pump directly with the circulating water, and it is possible to realize the initial water filling without air biting and cavitation. As a result, filling of the cooling water circulation circuit with the supplementary water can be completed without waiting for the filling time of the cooling water tank, and the initial filling time with the supplementary water can be shortened.

  Moreover, the fuel cell of the present invention performs initial water filling by directly supplying water to the cooling water circulation pump using direct water pressure. As a result, the cooling water circulation pump can be directly filled with circulating water, and initial water filling without air biting and cavitation can be realized. As a result, it is possible to shorten the initial filling time by shortening the waiting time for filling the cooling water by natural dripping from the cooling water tank into the cooling water circulation circuit.

  The fuel cell system of the present invention shortens the initial water filling time to the cooling circuit or makeup water supply circuit used in the fuel cell system and the like, shortens the power generation start time, and prevents air from being caught in the cooling circuit. Thus, it is possible to provide a fuel cell system that can obtain a sufficient cooling effect of the fuel cell, does not generate cavitation, and can improve the durability of the pump.

1 is a configuration diagram showing a fuel cell system according to Embodiment 1 of the present invention. The block diagram which shows the fuel cell system in Embodiment 2 of this invention The block diagram which shows the fuel cell system in Embodiment 3 of this invention The block diagram which shows the fuel cell system in Embodiment 4 of this invention Configuration diagram showing a conventional fuel cell system

  According to a first aspect of the present invention, there is provided a fuel cell that generates power by supplying hydrogen and air, a cooling water circulation circuit that circulates cooling water that cools the fuel cell that generates heat when the fuel cell generates power, and a cooling water circulation circuit. A cooling water tank that stores the cooling water, a cooling water circulation pump that circulates the cooling water in the cooling water circulation circuit, a hot water storage tank, a supplementary water circulation circuit that returns makeup water that has flowed out of the hot water storage tank to the hot water storage tank, A cooling water heat exchanger for exchanging heat between the cooling water in the cooling water circulation circuit and the makeup water in the makeup water circulation circuit, a water supply tank for storing makeup water from the hot water storage tank, and the makeup water in the water supply tank for the cooling water tank A supply pump that supplies the supply water to the supply pump, bypassing the water supply tank, bypassing the water supply tank, and supply water from the water storage tank and the supply water to the supply pump. First switching means for switching water flow is provided in any one of the first bypass paths, and the first switching means is controlled so that water flows through the first bypass path during water flush operation. A fuel cell system including a control unit is configured to perform initial water filling by directly supplying water to a makeup water supply circuit using direct water pressure. Thereby, the air biting of the pump can be prevented, stable water filling can be realized, and as a result, the initial water filling time can be shortened.

  According to a second invention, in particular, in the first invention, a second bypass path for bypassing the cooling water tank and supplying makeup water from the supply pump to the cooling water heat exchanger, and the supply pump And a second switching means for switching the supply water to either one of the cooling water tank and the second bypass path, and the control unit is configured to supply the second bypass path during water flush operation. In this fuel cell system, the second switching means is controlled so as to pass through the water, and the initial water filling is performed by directly supplying water to the makeup water supply circuit and the cooling water circuit using direct water pressure. As a result, it is possible to prevent the air from biting in the pump, realize stable water filling, and thus shorten the initial water filling time.

  According to a third invention, in particular, in the first invention, the water treatment device is disposed between the supply pump and the cooling water tank to purify water, and between the water treatment device and the cooling water tank. A third bypass path that bypasses the cooling water tank and supplies makeup water from the supply pump to the cooling water circulation pump, and supplies makeup water from the supply pump to the cooling water tank and the third bypass path. And further comprising a third switching means for switching the water flow to any one of them, wherein the control unit controls the third switching means to flow the water to the third bypass path during the water flush operation. In the battery system, by directly filling the cooling water circulation pump with water, stable air filling can be realized by preventing the pump from being caught by air, and thus the initial filling time can be shortened.

  According to a fourth aspect of the invention, there is provided a fuel cell that generates power by supplying hydrogen and air, a cooling water circulation circuit that circulates cooling water that cools the fuel cell that generates heat during power generation of the fuel cell, and a cooling water circulation circuit. A cooling water tank that stores the cooling water, a cooling water circulation pump that circulates the cooling water in the cooling water circulation circuit, a hot water storage tank, a supplementary water circulation circuit that returns makeup water that has flowed out of the hot water storage tank to the hot water storage tank, A cooling water heat exchanger for exchanging heat between the cooling water in the cooling water circulation circuit and the makeup water in the makeup water circulation circuit, a water supply tank for storing makeup water from the hot water storage tank, and the makeup water in the water supply tank for the cooling water tank A supply pump that supplies to the coolant, a second bypass path that bypasses the cooling water tank and supplies makeup water from the supply pump to the cooling water heat exchanger, and supplies makeup water from the supply pump to the front. A second switching means for switching water flow to either one of the cooling water tank and the second bypass path is provided, and the second switching is performed so as to pass water to the second bypass path during watering operation. It is a fuel cell system provided with the control part which controls a means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram showing a configuration example of the fuel cell system according to the first embodiment of the present invention.

  As shown in FIG. 1, a fuel cell system 100 is a fuel cell that generates hydrogen by generating a reforming reaction between a fuel cell 1 that generates and generates heat using fuel gas (hydrogen gas) and methane in the combustion gas. A machine 10 is provided.

  In the fuel cell 1, the fuel gas supplied to the anode (not shown) of the fuel cell 1 and the oxidizing gas (for example, air) supplied to the cathode (not shown) of the fuel cell 1 are electrochemical. In response to heat (exothermic reaction), power and heat are generated. The electric power generated by the fuel cell 1 can be used in various electric devices, for example. Further, the heat generated by the fuel cell 1 can be used for various purposes, for example, at home heating or hot water supply.

  The internal structure of the fuel cell 1 is known. Therefore, the detailed description is abbreviate | omitted. In the power generation of the fuel cell 1, since the above-described electrochemical reaction (exothermic reaction) proceeds, the operating temperature during power generation of the fuel cell 1 is maintained at a temperature suitable for the reaction (for example, about 70 ° C. to 80 ° C.). In general, a mechanism for keeping the temperature of the fuel cell 1 constant is generally employed.

  First, the fuel cell cooling circuit will be described.

  As shown in FIG. 1, the fuel cell cooling circuit includes a cooling water circulation circuit 2 that circulates cooling water for cooling the fuel cell 1 during power generation of the fuel cell 1, and a surplus provided in the cooling water circulation circuit 2. A cooling water tank 4 provided with a heater 3 for storing cooling water, a cooling water cooling water circulation pump 6 for circulating cooling water in the cooling water circulation circuit 2, and a hot water storage tank 20 that absorbs waste heat of the cooling water circulation circuit 2 A cooling water heat exchanger 5 for storing heat therein and a temperature detector 7 provided at the cooling water outlet of the fuel cell 1 are provided. In FIG. 1, the flow direction of the cooling water is indicated by a solid arrow. The cooling water circulation circuit 2 includes a cooling water circulation circuit a2a that connects the cooling water tank 4 and the cooling water heat exchanger 5, a cooling water circulation circuit b2b that connects the cooling water heat exchanger 5 and the fuel cell 1, and the fuel cell 1 and the cooling water circulation pump. 6, a cooling water circulation circuit c 2 c that connects the cooling water 6, and a cooling water circulation circuit d 2 d that connects the cooling water circulation pump 6 and the cooling water tank 4.

  Next, a reformed water supply circuit for supplying reaction water for the reforming reaction to the fuel processor 10 for supplying fuel gas (hydrogen gas) using city gas or the like to the fuel cell 1 will be described.

  The reforming water supply circuit includes a water supply circuit 12 branched from the cooling water circulation circuit d2d of the cooling water circulation circuit 2, a supply pump 11 for supplying reaction water to the fuel processor, and water for reaction to the fuel processor 10. The first fuel processing valve 15a for turning on and off, the condensed water circuit 14 branched from the supply pump 11, the second fuel processing valve 15b, the water supply tank (condensed water tank) 16, the supply pump 13, and the cooling A water supply circuit 17b is provided. In FIG. 1, the flow direction of the cooling water is indicated by dotted arrows. The water supply circuit 12 branches from a cooling water circulation circuit c2c that connects the fuel cell 1 and the cooling water circulation pump 6, and connects the water supply circuit a31 that connects the supply pump 11, the supply pump 11, and the first fuel processing valve 15a. b32, a water supply circuit c33 connecting the first fuel processing valve 15a and the fuel processor 10, a water supply circuit d34 branching from the water supply circuit b32 and connecting the second fuel processing valve 15b, and a second fuel A water supply circuit e35 connecting the processing valve 15b and a water supply tank (condensate water tank) 16 is formed.

  The cooling water supply circuit 17b includes a cooling water supply circuit c17c, a cooling water supply circuit d17d, and a cooling water supply circuit e17e.

  Next, the fuel cell power generation process will be described in the order of water flow, circulating water filling operation of the circulation circuit (hereinafter referred to as initial water filling) fuel treatment, and fuel cell power generation.

  Initial filling is performed to fill the circulation circuit of the fuel cell system with water.

  First, the circuit of the first switching means 61 provided in the first bypass circuit 60 is set to “open”. Thus, the makeup water in the hot water tank 20 passes through the hot water circulation circuit 41, the hot water circulation pump 21, and the makeup water circuit 51, passes through the first bypass circuit 60, and is supplied with the cooling water supply circuit c17c, the cooling water supply circuit d17d, and the ion exchange. The resin 18 and the cooling water supply circuit e17e are passed to the cooling water tank 4. These series of operations are performed by the supply pressure of the water supply applied to the hot water tank 20.

  When the water level in the cooling water tank 4 rises, the cooling water tank level switch 8 detects that the water level is full and “closes” the circuit of one switching means 61.

  Simultaneously with the initial water filling, water is supplied to the water supply tank (condensate water tank) 16. The water supply tank valve 22 is set to “open”, and the water stored in the hot water tank 20 is supplied through the hot water circulation circuit 41, the hot water circulation pump 21 and the hot water circulation circuit b42 through the makeup water circuit a51 and the makeup water circuit b52. Water tank) 16. When the water level in the feed water tank (condensate water tank) 16 rises, the feed water tank (condensate water tank) level switch 17 detects full water, stops the hot water circulation pump 21 and turns the feed water tank (condensate water tank) valve 22 to “ Closed. The operation is performed regardless of whether or not the hot water circulation pump 21 is in operation.

  When filling of the cooling water in the cooling water circulation circuit 2 is completed, fuel gas (hydrogen gas) is supplied from the fuel processor 10 to the fuel cell 1 and reacts with the oxidizing gas (for example, air) to start power generation. . Then, electric power and heat are generated by this power generation. This electric power is consumed by the electrical equipment, and the generated heat is heat-exchanged by the cooling water heat exchanger 5 from the hot water storage tank 20 by the hot water circulating through the makeup water circulation circuit 40 by the hot water storage circulation pump 21 and stored in the hot water storage tank 20. .

  The makeup water circulation circuit 40 includes a hot water storage circuit a41 that connects the hot water tank 20 and the hot water circulation pump 21, a supplementary water circuit b42 that connects the hot water circulation pump 21 and the cooling water heat exchanger 5, the cooling water heat exchanger 5 and the hot water tank. It is comprised from the makeup water circulation circuit c43 which connects 20.

  Further, when surplus electricity is generated during power generation in the fuel cell system, the surplus power is converted into heat by a heater and stored in the hot water tank 20. Specifically, surplus power is converted into hot water by the surplus heater 3 provided in the cooling water tank 4. The hot water in this cooling water tank is sent to the cooling water heat exchanger 5 by the cooling water circulation pump 6, and heat is exchanged from the hot water storage tank 20 by the hot water circulating through the makeup water circulation circuit 40 by the hot water storage circulation pump 21, and heat is stored in the hot water storage tank 20. Is done. The cooling water circulation pump 6 cannot be installed directly under the cooling water tank 4 because the water stored in the cooling water tank 4 heated by the surplus heater 3 becomes high temperature, and is downstream of the cooling water heat exchanger 5 and the fuel cell 1. It is installed at a position sufficiently away from the cooling water tank 4.

  As described above, according to the cooling water supply circuit of the cooling device used in the configured fuel cell system or the like, when filling the cooling water tank 4 as the initial water filling with the makeup water, the direct water pressure is used. Since the initial water filling is performed by supplying water directly, the initial water filling time can be shortened, and stable water filling can be performed without causing air clogging and cavitation in the supply pump.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIG.

  The description of the order of the power generation process of the fuel cell, water flow, circulating water filling operation of the circulation circuit, fuel processing, and power generation of the fuel cell is the same as (Embodiment 1), and is therefore omitted. The present embodiment is characterized by having a second bypass circuit 64 and a second switching means 65.

  That is, the second bypass circuit 64 is continuously connected to the initial water filling for filling the circulation circuit of the fuel cell system used in the first bypass circuit 60 and the first switching means 61 described in the first embodiment. And the initial water filling of the cooling water circulation circuit 2 is performed using the second switching means 65.

  First, the circuit of the first switching means 61 provided in the first bypass circuit 60 is set to “open”. As a result, the makeup water in the hot water tank 20 passes through the first hot water circulation circuit 41, the hot water circulation pump 21, the makeup water circuit 51, the first bypass circuit 60, the cooling water supply circuit c17c, the cooling water supply circuit d17d, and the ion exchange resin. 18 through the cooling water supply circuit e17e and led to the second bypass circuit 64. At this time, the circuit of the second switching means 65 is “open”. As a result, the makeup water in the hot water tank 20 is guided to the cooling water tank 4 through the cooling water heat exchanger 5 and the fuel cell 1 and the cooling water circulation pump 6.

  Next, when the water level in the cooling water tank 4 rises, the cooling water tank level switch 8 detects full water and closes the circuit of the second switching means 65 and the circuit of the first switching means 61.

  These series of operations are performed by the supply pressure of the water supply applied to the hot water tank 20. The subsequent operation is the same as that described in the first embodiment, and the description thereof is omitted.

(Embodiment 3)
Next, a third embodiment of the present invention will be described with reference to FIG.

  The description of the order of the power generation process of the fuel cell, water flow, circulating water filling operation of the circulation circuit, fuel processing, and power generation of the fuel cell is the same as (Embodiment 1), and is therefore omitted. The present embodiment is characterized by having a third bypass circuit 68 and a third switching means 69.

  That is, the third bypass circuit 68 continues to the initial water filling for filling the circulation circuit of the fuel cell system used in the first bypass circuit 60 and the first switching means 61 described in the first embodiment. And the initial water filling is performed directly on the cooling water circulation pump 6 of the cooling water circulation circuit 2 using the third switching means 69.

  First, the circuit of the first switching means 61 provided in the first bypass circuit 60 is set to “open”. As a result, the makeup water in the hot water tank 20 passes through the first hot water circulation circuit 41, the hot water circulation pump 21, the makeup water circuit 51, the first bypass circuit 60, the cooling water supply circuit c17c, the cooling water supply circuit d17d, and the ion exchange resin. 18, through the cooling water supply circuit e <b> 17 e, and led to the cooling water tank 4.

  Next, the circuit of the third switching means of the third bypass circuit 68 is set to “open”. As a result, the makeup water in the hot water tank 20 is led to the cooling water circulation pump 6 through the hot water storage circuit 41, the hot water circulation pump 21, the makeup water circuit 51, the first bypass circuit 60, the third bypass circuit 68. It is burned.

  Next, when the water level in the cooling water tank 4 rises, the cooling water tank level switch 8 detects full water, and the cooling tank valve 4b, the first switching means 61, and the third switching means 69 are closed. .

  These series of operations are performed by the supply pressure of the water supply applied to the hot water tank 20. The subsequent operation is the same as that described in the first embodiment, and the description thereof is omitted.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described with reference to FIG.

  The description of the order of the power generation process of the fuel cell, water flow, circulating water filling operation of the circulation circuit, fuel processing, and power generation of the fuel cell is the same as (Embodiment 1), and is therefore omitted. The present embodiment is characterized by having a second bypass circuit 64 and a second switching means 65.

  When the initial water filling is started, the water supply tank valve 22 is opened, and the hot water circulation pump 21 starts operation. Thereby, the makeup water in the hot water tank 20 is guided to the water supply tank 16 through the hot water circulation circuit 41, the hot water circulation pump 21, and the makeup water circuit 51.

  Next, when the water supply tank level switch 17 of the water supply tank 16 detects that the water supply tank 16 is full, the water supply tank valve 22 is “closed” and water supply to the water supply tank is stopped. Next, the supply pump 13 starts operation, and the replenishing water in the water supply tank 16 passes through the cooling water supply circuit c17c, the cooling water supply circuit d17d, the ion exchange resin 18, and the cooling water supply circuit e17e, and passes through the second bypass. Guided to circuit 64. At this time, the circuit of the second switching means 65 is “open”. As a result, the makeup water in the hot water tank 20 is guided to the cooling water tank 4 through the cooling water heat exchanger 5 and the fuel cell 1 and the cooling water circulation pump 6.

  Next, when the water level in the cooling water tank 4 rises, the cooling water tank level switch 8 detects that the water is full, and the circuit of the second switching means 65 is closed.

  The subsequent operation is the same as that described in the first embodiment, and the description thereof is omitted.

  As described above, the fuel cell system according to the present invention can fill the cooling water circulation circuit, the heat exchanger, and the fuel cell with cooling water without biting the air, and can realize the cooling water supply circuit and the cooling water circulation circuit that are pumped with air. . As a result, it is possible to provide a fuel cell system capable of ensuring sufficient heat exchange performance that satisfies the initial setting performance and performing stable power generation.

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Cooling water circulation circuit 3 Surplus heater 4 Cooling water tank 5 Cooling water heat exchanger 6 Cooling water circulation pump 7 Temperature detector 8 Cooling water tank level switch 10 Fuel processor 11 Supply pump 12 Water supply circuit 13 Supply pump 14 Condensed water Circuit 15a First fuel processing valve 15b Second fuel processing valve 16 Water supply tank (condensed water tank)
16b Overflow 17 Supply tank level switch 17b Cooling water supply circuit 18 Ion exchange resin 20 Hot water storage tank 21 Hot water storage circulation pump 40 Supply water circulation circuit

Claims (4)

A fuel cell that is supplied with hydrogen and air to generate electricity;
A coolant circulation circuit that circulates coolant for cooling the fuel cell that generates heat during power generation of the fuel cell;
A cooling water tank arranged in the cooling water circulation circuit and storing cooling water;
A cooling water circulation pump for circulating cooling water in the cooling water circulation circuit;
A hot water tank,
A makeup water circulation circuit for returning makeup water flowing out of the hot water tank to the hot water tank;
A cooling water heat exchanger for exchanging heat between the cooling water of the cooling water circulation circuit and the makeup water of the makeup water circulation circuit;
A water supply tank for storing makeup water from the hot water tank;
A supply pump for supplying makeup water from the water supply tank to the cooling water tank;
A first bypass path that bypasses the water supply tank and supplies makeup water from the hot water tank to the supply pump;
Comprising a first switching means for switching the supply water from the hot water storage tank to one of the water supply tank and the first bypass path;
A fuel cell system comprising a control unit for controlling the first switching means so that water flows through the first bypass path by water supply pressure applied to the hot water tank during a water beam operation. A second bypass path that bypasses the cooling water tank and supplies makeup water from the supply pump to the cooling water heat exchanger;
A second switching means for switching the supply water from the supply pump to one of the cooling water tank and the second bypass path;
2. The fuel cell system according to claim 1, wherein the control unit controls the second switching unit so that water flows through the second bypass path by a supply pressure of a water supply applied to the hot water storage tank during a water beam operation. A water treatment device disposed between the supply pump and the cooling water tank to purify water;
A third bypass path that bypasses the cooling water tank from between the water treatment device and the cooling water tank and supplies makeup water from the supply pump to the cooling water circulation pump;
And further comprising a third switching means for switching the supply water from the supply pump to one of the cooling water tank and the third bypass path,
2. The fuel cell system according to claim 1, wherein the control unit controls the third switching unit so that water flows through the third bypass path by a supply pressure of a water supply applied to the hot water tank during a water beam operation. A fuel cell that is supplied with hydrogen and air to generate electricity;
A coolant circulation circuit that circulates coolant for cooling the fuel cell that generates heat during power generation of the fuel cell;
A cooling water tank arranged in the cooling water circulation circuit and storing cooling water;
A cooling water circulation pump for circulating cooling water in the cooling water circulation circuit;
A hot water tank,
A makeup water circulation circuit for returning makeup water flowing out of the hot water tank to the hot water tank;
A cooling water heat exchanger for exchanging heat between the cooling water of the cooling water circulation circuit and the makeup water of the makeup water circulation circuit;
A water supply tank for storing makeup water from the hot water tank;
A supply pump for supplying makeup water from the water supply tank to the cooling water tank;
A second bypass path that bypasses the cooling water tank and supplies makeup water from the supply pump to the cooling water heat exchanger;
Comprising second switching means for switching the makeup water from the supply pump to one of the cooling water tank and the second bypass path;
A fuel cell system comprising: a control unit that controls the second switching means so that water flows through the second bypass path by water supply pressure applied to the hot water tank during a water beam operation.