JP2008288038A - Fuel cell scavenging method, humidifier, and fuel cell system - Google Patents

Abstract

To provide a fuel cell scavenging method, a humidifier, and a fuel cell system that realize high-speed scavenging by suppressing an increase in auxiliary equipment and suppressing humidification during scavenging with a simple configuration.
In a method of scavenging a fuel cell 2 that performs an electrochemical reaction using an oxidizing gas humidified by a humidifier 15, the humidifier 15 has the oxidizing gas flowing from one end to the other end. The fuel cell is blocked by the oxidizing gas that has passed through the humidifier 15 in a state where the flow at the outer periphery of the oxidizing gas flow path of the humidifier 15 is inhibited and the flow rate at the center is relatively increased. Perform scavenging.
[Selection] Figure 1

Description

  The present invention relates to a humidifier capable of humidifying a reaction gas of a fuel cell, a fuel cell system including the humidifier, and a scavenging method of the fuel cell, and more particularly to a technique for scavenging for the purpose of preventing freezing of the fuel cell. .

  In recent years, fuel cells that generate electricity using an electrochemical reaction between hydrogen and oxygen have attracted attention as energy sources. For example, in a polymer electrolyte fuel cell which is a kind of fuel cell, a solid polymer electrolyte membrane may be referred to as a hydrogen electrode (hereinafter sometimes referred to as “anode”) and an oxygen electrode (hereinafter referred to as “cathode”). ) And a stack in which a plurality of cells formed by being sandwiched from both sides are provided.

  The fuel cell is supplied with hydrogen gas as fuel at the anode and air as oxidant at the cathode. For example, in the case of a solid polymer fuel cell, hydrogen supplied to the anode generates hydrogen ions by reaction with the catalyst of the anode, and the hydrogen ions pass through the solid polymer electrolyte membrane, and oxygen and oxygen at the cathode. It generates electricity by causing an electrochemical reaction.

  Further, the air as the oxidizing gas supplied to the fuel cell needs to be appropriately adjusted in humidification amount in order to perform efficient power generation. Therefore, a humidifier is used to extract moisture from the exhaust air (oxidation off gas) having a high humidity exhausted from the fuel cell, and the humidity supplied to the fuel cell is humidified by this moisture to increase the humidity.

By the way, the electrochemical reaction between hydrogen and oxygen during the operation of the fuel cell involves the generation of water. If the generated water remains inside the fuel cell, it may cause damage to the fuel cell due to freezing. Therefore, in order to prevent the fuel cell from freezing, it causes freezing by sending air (oxidizing gas) into the fuel cell. It is necessary to perform scavenging for discharging water and water vapor (see, for example, Patent Document 1).
JP 2001-216987 A

However, when a humidifier that humidifies the oxidizing gas as described above is provided, scavenging may take time because the degree of humidification (humidity) of the air sent to the fuel cell increases. One countermeasure in this case is to send air that bypasses the humidifier during the scavenging operation to the fuel cell.
However, in order to bypass the humidifier, a total of four valves are installed in the air compressor gas line and the fuel cell outlet gas line connected to the humidifier, and the bypass line for these lines to bypass the humidifier. It will be necessary. In addition, all these opening / closing controls are required. Furthermore, since the heat exchange function which is one of the functions of the humidifier is not performed, it is necessary to control the air compressor gas temperature before scavenging.
That is, the number of auxiliary machines increases due to the addition of the number of valves, and there are problems such as an increase in weight, cost and fuel consumption, complicated piping (larger cathode system), and increased control items during scavenging.

  In view of the above circumstances, the present invention provides a fuel cell scavenging method, a humidifier, and a fuel cell system that realize high-speed scavenging by suppressing humidification during scavenging with a simple configuration while suppressing an increase in auxiliary equipment. The purpose is to do.

  In order to achieve the above object, a fuel cell scavenging method according to the present invention is a method of scavenging a fuel cell that performs power generation by an electrochemical reaction using an oxidizing gas humidified by a humidifier. In which the oxidizing gas flows from one end to the other end, obstructing the flow of the outer periphery of the oxidizing gas flow path of the humidifier, and relatively increasing the flow rate at the center, The fuel cell is scavenged by the oxidizing gas that has passed through the humidifier.

The outer peripheral portion has higher humidification performance than the central portion. Utilizing this characteristic, the humidifying performance of the humidifier is lowered by making the flow at the outer peripheral portion relatively lower than that at the central portion during scavenging. As a result, the humidification amount of the gas scavenging the fuel cell is reduced, and the scavenging time of the fuel cell can be shortened.
During scavenging, the gas may not flow at all around the outer periphery.

  The scavenging method for a fuel cell according to the present invention is a method for scavenging a fuel cell that generates electricity by an electrochemical reaction using an oxidizing gas humidified by a humidifier. The oxidizing gas flows to the end, and the fuel cell is scavenged by the oxidizing gas that has passed through the humidifier while the outer periphery of the oxidizing gas flow path of the humidifier is cooled. is there.

  The outer peripheral portion has higher humidification performance than the central portion. Further, the humidifier has higher humidification performance as the temperature is higher. Utilizing this characteristic, the temperature of the outer peripheral portion is lowered during scavenging to reduce the humidification performance. As a result, the humidification amount of the gas scavenging the fuel cell is reduced, and the scavenging time of the fuel cell can be shortened.

  Further, the humidifier of the present invention is a humidifier provided with a flow path that guides gas from one end to the other end and humidifies the gas in the process. The intersecting tanks are arranged, and the fluid is stored in the tanks, whereby the outer periphery of the flow path is blocked.

  When a fluid (for example, water) is accumulated in the tank, the water becomes a pressure loss and the gas flow at the outer periphery of the flow path is obstructed. As a result, the flow rate at the outer peripheral portion with high humidification performance decreases, and the flow rate at the center portion of the flow path with low humidification performance increases relatively. As a result, the humidification performance of the humidifier decreases.

  Further, the humidifier of the present invention is a humidifier provided with a flow path that guides gas from one end to the other end and humidifies the gas in the process. The cooling means for cooling the part is provided.

  The outer peripheral part of the channel has higher humidification performance than the central part. Further, the humidifier has higher humidification performance as the temperature is higher. Therefore, when the temperature of the outer peripheral portion is lowered by the cooling means, the humidifying performance of the humidifier is lowered.

  The cooling means can employ a structure that cools the gas at the outer periphery by flowing a refrigerant. That is, when applied to a fuel cell system, the cooling line that guides the refrigerant to the cooling means of the humidifier may be configured to branch from a refrigerant piping system that circulates the refrigerant that cools the fuel cell. it can. Thereby, cooling of the flow-path outer peripheral part of a humidifier is realizable easily.

  Further, the humidifier of the present invention is a humidifier having a flow path that guides gas from one end to the other end and humidifies the gas in the process. Gas is supplied independently.

  More specifically, a center valve line for introducing gas to the outer periphery of the flow path and an outer peripheral line for introducing gas to the outer periphery of the flow path are provided, and at least a shut valve for opening and closing the flow path of the outer peripheral line is provided. . Thereby, if the shut valve is closed and the supply of gas to the outer peripheral line is stopped, all the gas passes through the central line, thereby stopping the use of the outer peripheral part of the flow path with high humidification performance. As a result, the humidification amount of the gas scavenging the fuel cell decreases.

  Further, as a fuel cell system equipped with such a humidifier, a fuel cell, an oxidizing gas supply path for supplying an oxidizing gas to the fuel cell, and an exhaust path for leading an off-gas of the oxidizing gas exhausted from the fuel cell, A fuel cell system including the humidifier may be used as a humidifier that humidifies the oxidizing gas supplied to the fuel cell using the off-gas of the oxidizing gas.

  By providing the humidifier, the humidifying performance of the humidifier during scavenging can be reduced, and it becomes possible to supply a low-humidity gas to the fuel cell.

  According to the fuel cell scavenging method, the humidifier, and the fuel cell system of the present invention, the humidifying performance of the humidifier can be easily reduced without providing a flow path for bypassing the humidifier. The scavenging of the fuel cell can be performed quickly without causing problems such as an increase, complication of the piping system, cost increase and fuel consumption deterioration.

<First Embodiment>
Hereinafter, a humidifier according to a preferred embodiment of the present invention and a fuel cell system including the humidifier will be described with reference to the accompanying drawings. First, a fuel cell system to which the humidifier of this embodiment can be applied will be described. The fuel cell system of the present embodiment can be mounted on a vehicle such as a fuel cell vehicle (FCHV), an electric vehicle, or a hybrid vehicle. However, the present invention is not limited to such an application example, and may be a ship, an aircraft, The present invention can be applied to all moving objects such as trains and walking robots, and can also be applied to stationary power generation systems in which fuel cells are used as power generation equipment for buildings (housing, buildings, etc.).

  The fuel cell system 1 shown in FIG. 1 supplies a fuel cell 2, an oxidizing gas piping system 3 that supplies air (oxygen) as an oxidizing gas to the fuel cell 2, and a hydrogen gas as a fuel gas to the fuel cell 2. A fuel gas piping system 4, a refrigerant piping system 5 that supplies a refrigerant to the fuel cell 2 to cool the fuel cell 2, a power system 6 that charges and discharges the power of the system 1, and a control unit that controls the entire system. 7.

  The fuel cell 2 is formed of, for example, a solid polymer electrolyte type and has a stack structure in which a large number of single cells are stacked. The single cell has an air electrode (cathode) on one surface of an electrolyte made of an ion exchange membrane, a fuel electrode (anode) on the other surface, and a pair of the air electrode and the fuel electrode sandwiched from both sides. Of separators. The oxidizing gas is supplied to the oxidizing gas channel 2a of one separator, and the fuel gas is supplied to the fuel gas channel 2b of the other separator. The fuel cell 2 generates electric power by the electrochemical reaction of the supplied fuel gas and oxidizing gas. The electrochemical reaction in the fuel cell 2 is an exothermic reaction, and the temperature of the solid polymer electrolyte fuel cell 2 is approximately 60 to 80 ° C.

  The oxidizing gas piping system 3 has a supply path 11 through which the oxidizing gas supplied to the fuel cell 2 flows, and a discharge path 12 through which the oxidizing off gas discharged from the fuel cell 2 flows. The downstream end of the supply path 11 communicates with the upstream end of the oxidizing gas flow path 2a, and the upstream end of the discharge path 12 communicates with the downstream end of the oxidizing gas flow path 2a. Further, the oxidizing off gas is in a highly moist state because it contains moisture generated by the cell reaction of the fuel cell 2.

  The supply path 11 is provided with a compressor 14 (compressor) that takes in the oxidizing gas (outside air) via the air cleaner 13, and a humidifier 15 that humidifies the oxidizing gas pumped to the fuel cell 2 by the compressor 14. Yes. The humidifier 15 exchanges moisture between the low-humidity oxidizing gas flowing in the supply passage 11 and the high-humidity oxidizing off-gas flowing in the discharge passage 12, and appropriately supplies the oxidizing gas supplied to the fuel cell 2. Humidify.

  The back pressure of the oxidizing gas supplied to the fuel cell 2 is regulated by a pressure regulating valve 16 disposed in the discharge path 12 near the cathode outlet. The pressure regulating valve 16 is, for example, a valve driven by a step motor, and is electrically connected to the control unit 7. The valve opening degree of the pressure regulating valve 16 is configured to be adjustable by the control unit 7 in an arbitrary range including full open, half open, and full close. The oxidizing off gas passes through the pressure regulating valve 16 and the humidifier 15 and is finally exhausted into the atmosphere outside the system as exhaust gas.

  The fuel gas piping system 4 includes a hydrogen supply source 21, a supply path 22 through which hydrogen gas supplied from the hydrogen supply source 21 to the fuel cell 2 flows, and a supply path for supplying hydrogen offgas (fuel offgas) discharged from the fuel cell 2. 22, a circulation path 23 for returning to the junction point A of 22, a pump 24 that pumps the hydrogen off-gas in the circulation path 23 to the supply path 22, and a purge path 25 that is branched and connected to the circulation path 23. . The hydrogen gas flowing out from the hydrogen supply source 21 to the supply path 22 by opening the main valve 26 is supplied to the fuel cell 2 through the pressure regulating valve 27 and other pressure reducing valves and the shutoff valve 28. The purge passage 25 is provided with a purge valve 33 for discharging the hydrogen off gas to a hydrogen diluter (not shown).

  The refrigerant piping system 5 includes a refrigerant channel 41 communicating with the cooling channel 2 c in the fuel cell 2, a cooling pump 42 provided in the refrigerant channel 41, and a radiator that cools the refrigerant discharged from the fuel cell 2 ( Cooling means) 43, a bypass flow path 44 that bypasses the radiator 43, and a switching valve 45 that sets the flow of cooling water to the radiator 43 and the bypass flow path 44. The cooling pump 42 circulates and supplies the refrigerant in the refrigerant channel 41 to the fuel cell 2 by driving the motor.

  The power system 6 includes a high-voltage DC / DC converter 61, a battery 62, a traction inverter 63, a traction motor 64, and various auxiliary inverters 65, 66, and 67. The high-voltage DC / DC converter 61 is a direct-current voltage converter that adjusts the direct-current voltage input from the battery 62 and outputs it to the traction inverter 63 side, and the direct-current input from the fuel cell 2 or the traction motor 64. And a function of adjusting the voltage and outputting it to the battery 62. The charge / discharge of the battery 62 is realized by these functions of the high-voltage DC / DC converter 61. Further, the output voltage of the fuel cell 2 is controlled by the high voltage DC / DC converter 61.

  The traction inverter 63 converts a direct current into a three-phase alternating current and supplies it to the traction motor 64. The traction motor 64 (power generation device) is, for example, a three-phase AC motor. The traction motor 64 constitutes, for example, a main power source of the vehicle 100 on which the fuel cell system 1 is mounted, and is connected to the wheels 101L and 101R of the vehicle 100. Auxiliary machine inverters 65, 66, and 67 control driving of motors 14a, 24a, and 42a of compressor 14, pump 24, and cooling pump 42, respectively.

  The control unit 7 is configured as a microcomputer including a CPU, a ROM, and a RAM inside. The CPU executes a desired calculation according to the control program and performs various processes and controls. The ROM stores control programs and control data processed by the CPU. The RAM is mainly used as various work areas for control processing.

  The control unit 7 includes a pressure sensor and a temperature sensor used in the gas system (3, 4) and the refrigerant system 5, an outside air temperature sensor that detects an outside air temperature in the environment where the fuel cell system 1 is placed, and an accelerator opening of the vehicle 100. Detection signals from various sensors such as an accelerator opening sensor for detecting the degree are input, and a control signal is output to each component (compressor 14, pressure regulating valve 16, etc.).

  FIG. 2 shows the humidifier 15. The humidifier 15 is configured by housing a hollow fiber bundle 81 inside a casing 80. The hollow fiber bundle 81 is a bundle of a plurality of hollow fibers 81a, and the compressed oxidizing gas introduced from the compressed oxidizing gas inlet 80a provided in the casing 80 on one end (for example, the upper end of the paper surface) flows into each hollow fiber 81a. The casing 80 is discharged from a compressed oxidizing gas outlet 80b provided at the other end (for example, the lower end of the paper). On the peripheral wall of the casing 80, a humidified gas inlet 80c is provided in the vicinity of the compressed oxidizing gas outlet 80b, and a humidified gas outlet 80d is provided in the vicinity of the compressed oxidized gas inlet 80a.

Further, potting portions 83 are provided at both ends of the casing 80. A water tank 85 is provided in the potting portion 83 on the compressed oxidizing gas inlet 80a side. Further, the outer peripheral side of the hollow fiber bundle 81 in the vicinity of the compressed oxidizing gas inlet 80 a is cut, and a part of the water tank 85 is inserted inside the outer peripheral portion of the hollow fiber bundle 81.
The water tank 85 is configured such that liquid water stored in the gas-liquid separator 86 is supplied via the flow path 87. A supply shut valve 88 is provided in the flow path 87. Further, a drainage channel 89 for draining water from the water tank 85 is provided, and an exhaust shut-off valve 90 is provided in the drainage channel 89. The gas-liquid separator 86 can be configured to extract water from the gas at the inlet side or the outlet side of the humidifier 15.

A scavenging method for the fuel cell 2 using the humidifier 15 configured as described above will be described. The scavenging control is performed by the control unit 7. First, at the time of cathode line scavenging, the exhaust shut valve 90 is first closed, the supply shut valve 88 is opened, and the water accumulated in the gas-liquid separator 86 is started to be introduced into the water tank 85. When the predetermined time has passed, the supply shut valve 88 is closed.
Subsequently, a scavenging flow rate is passed through the compressor 14 to scavenge the cathode line. A dry compressed oxidant gas is introduced into the humidifier 15 from the compressed oxidant gas inlet 80a, and a high-humidity oxidant off-gas discharged from the fuel cell 2 is introduced into the humidified gas inlet 80c. The dried compressed oxidizing gas is humidified by the high-humidity oxidizing off gas through the hollow fiber bundle 81. Thereafter, the compressed oxidizing gas is discharged from the compressed oxidizing gas outlet 80b, and the oxidizing off gas is discharged from the humidified gas outlet 80d.

  Here, in general, the outer peripheral portion of the hollow fiber bundle 81 has high humidification performance, and the central portion has low humidification performance (see FIG. 3). As described above, since the water tank 85 filled with water is provided at the outer peripheral portion, the resistance of the gas flow in the humidifier 15 is increased at the outer peripheral portion where water is added, and the oxidizing gas does not flow easily. In this case, the gas (compressed oxidant gas) mainly flows through the central portion with low humidification performance. As a result, the degree of humidification with respect to the introduced oxidant gas is suppressed and discharged from the humidifier 15, and the fuel cell 2. To be introduced.

  After completion of scavenging, the exhaust shut valve 90 is opened, and the water in the water tank 85 is discharged. During normal operation, the humidifier 15 is used without storing water in the water tank 85.

  In the humidifier 15 of the present embodiment configured as described above, the oxidizing gas flows in the central portion where the humidifying performance is low, so that the oxidizing gas humidification amount during scavenging is reduced and the humidification amount to the fuel cell 2 is reduced. Can be made. That is, it is possible to quickly scavenge the fuel cell without causing problems such as weight increase, complicated piping system, cost increase and fuel consumption deterioration.

Second Embodiment
Next, a second embodiment of the present invention will be described. In addition, since the whole structure of a fuel cell system is the same as that of the said 1st Embodiment, description is abbreviate | omitted.
The humidifier 95 according to the present embodiment shown in FIG. 4 has a configuration in which cooling water is introduced from the refrigerant system 5 and the outer peripheral portion of the hollow fiber bundle is cooled. The humidifier 95 is formed by housing a hollow fiber bundle 81 inside a casing 96. The hollow fiber bundle 81 is a bundle of a plurality of hollow fibers 81a, and the compressed oxidant gas in the supply passage 11 introduced from the compressed oxidant gas inlet 96a provided in the casing 80 on one end (for example, the upper end of the paper surface) is each hollow fiber 81a. And is discharged from a compressed oxidizing gas outlet 96b provided at the other end of the casing 96 (for example, the lower end of the drawing). A humidified gas inlet 96c is provided in the vicinity of the compressed oxidizing gas outlet 96b on the peripheral wall of the casing 96, and a humidified gas outlet 96d is provided in the vicinity of the compressed oxidized gas inlet 96a. Furthermore, potting portions 97 are provided at both ends of the casing 96.

  In the humidifier 95 of the present embodiment, an outer periphery cooling line 98 is provided between the hollow fiber bundle 81 and the inner wall of the casing 96. The outer periphery cooling line 98 is a plurality of cooling water pipes extending from one end to the other end in the longitudinal direction of the casing 96, and the radiator 43 is connected to one end of the casing 96 via a cooling line 99 branched from the refrigerant flow path 41. The cooling water cooled by the above is supplied, and the cooling water discharged from the other end is returned to the refrigerant flow path 41 again. The cooling line 99 is provided with a shut valve 94 that opens and closes the supply of cooling water to the cooling line 99.

A scavenging method for the fuel cell 2 using the humidifier 95 configured as described above will be described. The scavenging control is performed by the control unit 7. First, at the time of cathode line scavenging, the shut valve 94 is opened, and cooling water is caused to flow through the outer periphery cooling line 98 of the humidifier 95.
Subsequently, a scavenging flow rate is passed through the compressor 14 to scavenge the cathode line. A dry compressed oxidant gas is introduced into the humidifier 95 from the compressed oxidant gas inlet 96a, and a high-humidity oxidant off-gas discharged from the fuel cell 2 is introduced into the humidified gas inlet 96c. The dried compressed oxidizing gas is humidified by the high-humidity oxidizing off gas through the hollow fiber bundle 81. Thereafter, the compressed oxidizing gas is discharged from the compressed oxidizing gas outlet 96b, and the oxidizing off gas is discharged from the humidified gas outlet 96d.

At that time, the temperature of the outer peripheral portion of the humidifier 95 is lowered by the cooling water, and the humidification performance is lowered. That is, the low-humidity oxidizing gas is supplied to the fuel cell 2 by reducing the humidifying performance of the outer peripheral portion having high humidifying performance with the cooling water.
During normal operation, the humidifier 95 is used in a state where the shut valve 94 is closed and the outer periphery of the humidifier 95 is not cooled.

  In the humidifier 95 of the present embodiment configured as described above, the humidification performance of the humidifier 95 is reduced, so that the amount of humidification of the oxidizing gas during scavenging is reduced, and the amount of humidification to the fuel cell 2 is easily reduced. Can be made. That is, it is possible to quickly scavenge the fuel cell without causing problems such as weight increase, complicated piping system, cost increase and fuel consumption deterioration.

<Third Embodiment>
Next, a third embodiment of the present invention will be described. In addition, since the whole structure of a fuel cell system is the same as that of the said 1st Embodiment, description is abbreviate | omitted.
The humidifier 102 shown in FIG. 5 includes a hollow fiber bundle 81 accommodated in the casing 103. The hollow fiber bundle 81 is a bundle of a plurality of hollow fibers 81 a, and the supply path 11 introduced from the central part gas inlet 104 provided in the casing 103 on one end (for example, the upper end of the paper surface) and the outer peripheral gas inlet 105. The compressed oxidizing gas flows into each hollow fiber 81a and is discharged from a compressed oxidizing gas outlet 103b provided at the other end of the casing 103 (for example, the lower end of the paper). On the peripheral wall of the casing 103, a humidified gas inlet 103c is provided in the vicinity of the compressed oxidizing gas outlet 103b, and a humidified gas outlet 103d is provided on the other end side. Further, potting portions 106 are provided at both ends of the casing 103.

  The central gas inlet 104 is opened facing the center of the hollow fiber bundle 81, and the compressed oxidizing gas introduced from the central line 108 continuing from the supply path 11 through the central gas inlet 104 is hollow. Guided to the center of the yarn bundle 81. The outer peripheral gas inlet 105 is positioned so as to surround the central gas inlet 104, and the compressed oxidizing gas introduced from the outer peripheral line 107 branched from the supply path 11 through the outer peripheral gas inlet 105 is a hollow fiber bundle. 81 is guided to the outer peripheral portion. The outer peripheral line 107 is provided with a shut valve 109. By opening and closing the shut valve 109, it is determined whether the gas in the supply path 11 is allowed to flow only in the central part of the humidifier 102 or in both the central part and the outer peripheral part. Can be determined.

A fuel cell scavenging method using the humidifier 102 configured as described above will be described. The scavenging control is performed by the control unit 7. First, during the cathode line scavenging, the shut valve 109 is closed, and the oxidizing gas introduced from the supply passage 11 is introduced into the central gas inlet 104 through the central line 108.
A scavenging flow rate is passed through the compressor 14 to scavenge the cathode line. A dry compressed oxidizing gas is introduced into the central portion of the humidifier 102 from the central gas inlet 104, and a high-humidity oxidizing off gas discharged from the fuel cell 2 is introduced into the humidified gas inlet 103c. The dried compressed oxidizing gas is humidified by the high-humidity oxidizing off gas through the hollow fiber bundle 81. Thereafter, the compressed oxidizing gas is discharged from the compressed oxidizing gas outlet 103 b, and the oxidizing off gas is discharged from the casing 103.
During normal operation, the humidifier 102 is used in a state where the shut valve 109 is opened and the oxidizing gas is also sent from the supply path 11 to the outer peripheral portion of the humidifier 102 via the outer peripheral gas inlet 105. .

  In the humidifier 102 of the present embodiment configured as described above, by not using the outer peripheral portion of the humidifier 102 with high humidification performance, the amount of humidification of the oxidizing gas during scavenging is reduced, and the amount of humidification to the fuel cell 2 Can be easily reduced. That is, it is possible to quickly scavenge the fuel cell without causing problems such as weight increase, complicated piping system, cost increase and fuel consumption deterioration.

1 is a system configuration diagram schematically illustrating an embodiment of a fuel cell system including a humidifier according to the present invention. It is sectional drawing to which the humidifier was expanded. It is the figure which showed the relationship between the water tank installation position and humidification performance of the humidifier. It is sectional drawing of the humidifier shown as 2nd Embodiment. It is sectional drawing of the humidifier shown as 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 2 ... Fuel cell, 3 ... Oxidation gas piping system, 5 ... Refrigerant piping system, 7 ... Control part, 11 ... Supply path, 12 ... Discharge path, 14 ... Compressor, 15 ... Humidifier, 23 ... Circulation path 41. Refrigerant flow path 43 43 Radiator (cooling means) 85 Water tank 95 Humidifier 98 Perimeter cooling line 99 Cooling line 102 Humidifier

Claims (7)

In a method of scavenging a fuel cell that performs power generation by an electrochemical reaction using an oxidizing gas humidified by a humidifier,
The humidifier is one in which the oxidizing gas flows from one end to the other end inside the humidifier, obstructs the flow of the outer peripheral portion of the oxidizing gas flow path of the humidifier, and makes the flow rate at the center relatively A scavenging method for a fuel cell, wherein the scavenging of the fuel cell is performed with the oxidizing gas that has passed through the humidifier in a state where the fuel cell is increased. In a method of scavenging a fuel cell that performs power generation by an electrochemical reaction using an oxidizing gas humidified by a humidifier,
The humidifier is one in which the oxidizing gas flows from one end to the other end inside the humidifier, and the humidifier passes through the humidifier in a state where the outer peripheral portion of the oxidizing gas channel of the humidifier is cooled. A fuel cell scavenging method for scavenging the fuel cell with an oxidizing gas. In a humidifier equipped with a flow path that guides gas from one end to the other, and the gas is humidified in the process,
A humidifier in which a tank that intersects with the flow path is disposed at an outer peripheral portion of the flow path, and a fluid is stored in the tank, thereby inhibiting a gas flow at the outer peripheral portion of the flow path. In a humidifier equipped with a flow path that guides gas from one end to the other, and the gas is humidified in the process,
A humidifier, wherein a cooling means for cooling the outer periphery of the flow path is provided on the outer periphery of the flow path. In a humidifier equipped with a flow path that guides gas from one end to the other, and the gas is humidified in the process,
A humidifier in which gas is supplied independently to the central portion of the flow channel and the outer peripheral portion of the flow channel. A fuel cell, an oxidizing gas supply path for supplying an oxidizing gas to the fuel cell, an exhaust path for leading off-gas of the oxidizing gas exhausted from the fuel cell, and the oxidizing gas supplied to the fuel cell using the off-gas A fuel cell system comprising a humidifier for humidifying oxidizing gas,
The fuel cell system, wherein the humidifier is the humidifier according to any one of claims 3 to 5. A fuel cell, an oxidizing gas supply path for supplying an oxidizing gas to the fuel cell, an exhaust path for leading off-gas of the oxidizing gas exhausted from the fuel cell, and the oxidizing gas supplied to the fuel cell using the off-gas A fuel cell system comprising a humidifier that humidifies the oxidizing gas and a refrigerant piping system that circulates a refrigerant that cools the fuel cell.
5. The fuel cell system according to claim 4, wherein the humidifier is a humidifier according to claim 4, and a cooling line that guides the refrigerant to a cooling unit of the humidifier is branched from the refrigerant piping system.

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