JP6135863B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system having a fuel cell stack that generates power using fuel gas and oxidant gas.

  Auxiliary machinery such as valves and pumps that supply fuel gas and oxidant gas for power generation to the fuel cell stack need to be designed in consideration of freezing so that they can be driven stably even in cold regions. For this reason, a fuel cell system is known in which when an auxiliary machine freezes, the auxiliary machine is thawed using hot water or a heater. However, the freezing countermeasure by such a method has a problem that the configuration becomes complicated and it is not economical.

  In this regard, in the fuel cell system described in Patent Document 1 below, freezing is prevented by housing an auxiliary machine inside the casing. In other words, the casing is heated by the heat generated during power generation of the fuel cell stack, and the temperature of the auxiliary machine accommodated in the casing is kept above the melting point of water, thereby preventing the auxiliary machine from freezing.

JP 2011-204500 A

  However, in the fuel cell system described in Patent Document 1, freezing during non-power generation (when the fuel cell stack is stopped) has not been considered. For example, when oxygen-containing air is supplied to the fuel cell stack as an oxidant gas for power generation, there is a problem that water vapor contained in the air condenses inside the piping during non-power generation and causes freezing. It was. In addition, when freezing occurs inside the flow rate adjustment valve that changes the cross-sectional area of the flow path inside the pipe, the valve body in the flow rate adjustment valve may be fixed by ice. In this case, when power generation is subsequently started, the valve body cannot be moved to a desired position in the flow rate adjusting valve, and there is a possibility that the air flow rate cannot be adjusted appropriately.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fuel cell system that prevents freezing inside the flow rate adjusting valve even during non-power generation.

  In order to solve the above problems, a fuel cell system according to the present invention is a fuel cell system that generates power using a fuel gas and an oxidant gas, and generates power by supplying the fuel gas and the oxidant gas. A fuel cell stack to be performed; an air supply pipe that internally forms a flow path for supplying air to the fuel cell stack; and a flow rate adjustment that is provided in the air supply pipe and changes a cross-sectional area of the internal flow path And the air supply pipe has at least a part thereof a dew condensation promoting part having a smaller heat capacity than the flow rate adjusting valve.

  According to the fuel cell system of the present invention, the air supply pipe has at least a dew condensation promoting portion having a heat capacity smaller than that of the flow rate adjusting valve. Therefore, the dew condensation promoting portion causes more condensation than the flow rate adjusting valve. It becomes easy. Therefore, during non-power generation, condensation is preferentially generated by the condensation promoting unit, thereby reducing water vapor contained in the air inside the flow rate adjustment valve and suppressing the occurrence of condensation and freezing inside the flow rate adjustment valve. Can do.

  In the fuel cell system according to the present invention, it is preferable that the fuel cell system further includes an auxiliary machine casing that houses the flow rate adjusting valve, and the dew condensation promoting part is housed inside the auxiliary machine casing.

  According to the fuel cell system of the present invention, it is possible to dispose the condensation promoting part and the flow rate adjusting valve close to each other by housing the condensation promoting part in the auxiliary machine casing in the same manner as the flow rate regulating valve. It becomes. Therefore, it is possible to reliably reduce the amount of water vapor contained in the air inside the flow control valve during non-power generation, and to further suppress the occurrence of condensation and freezing inside the flow control valve.

  In the fuel cell system according to the present invention, it is also preferable that the dew condensation promoting part is provided at a position lower than the flow rate adjusting valve.

  According to the fuel cell system of the present invention, by providing the uppermost part inside the dew condensation promoting part at a position lower than the uppermost part inside the flow rate adjusting valve, the dew condensation water generated in the dew condensation promoting part is transferred to the inside of the air supply pipe. Can be prevented from flowing toward the flow rate adjustment valve. Therefore, it is possible to prevent the condensed water generated in the condensation promoting part from reaching the flow rate adjusting valve and freezing.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell system which prevents the freezing in the inside of a flow regulating valve can be provided also at the time of non-power generation.

1 is a perspective view of a fuel cell system according to an embodiment of the present invention. It is a side view of the state which removed the auxiliary machine cover of the fuel cell system which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate understanding, the same components are denoted by the same reference numerals as much as possible in the drawings, and redundant description is omitted.

  First, an outline of a fuel cell system 10 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view showing a fuel cell system 10 according to an embodiment of the present invention.

  The fuel cell system 10 is mounted on a vehicle and includes a fuel cell unit 20 and an auxiliary unit 30 as shown in FIG.

  The fuel cell unit 20 is a unit that generates electric power and supplies it to a vehicle drive motor (not shown) or the like, and has a box-shaped fuel cell casing 21. The fuel cell casing 21 has a fixed portion 23 projecting from the outer surface thereof, and a bolt (not shown) is inserted into a bolt hole 24 penetrating the fixed portion 23 in the Z direction. (Not shown). Further, the fuel cell casing 21 accommodates a fuel cell stack 22 therein.

  The fuel cell stack 22 is configured by laminating a plurality of plate-like fuel cells 22a, which are polymer electrolyte fuel cells, in the Z direction. The fuel cell stack 22 generates electric power by generating an electrochemical reaction using the supplied hydrogen gas and oxidant gas, and the electric power is supplied via an electrode member (not shown) such as a bus bar. It is supplied to a drive motor (not shown) of the vehicle.

  The auxiliary unit 30 is a unit that is provided on the side of the fuel cell unit 20 and supplies oxidant gas to the fuel cell stack 22. The auxiliary machine unit 30 has an auxiliary machine casing 31 formed in a box shape, and equipment such as a flow rate adjusting valve 40 to be described later is accommodated therein. The equipment accommodated in the auxiliary machine casing 31 is covered with an auxiliary machine cover 32 that is detachable for maintenance.

  An opening 32 a that communicates the inside and outside of the accessory casing 31 is opened at the end of the accessory cover 32. The opening 32 a is covered with a plate-like flange 33. A flange 35 is provided with a joint 35, and an inlet side pipe 34 is inserted into the auxiliary machine casing 31 through the joint 35.

  Next, the internal configuration of the auxiliary machine casing 31 will be described with reference to FIG. FIG. 2 is a side view of the fuel cell system 10 according to the embodiment of the present invention with the auxiliary cover 32 removed.

  Inside the auxiliary machine casing 31, a flow rate adjusting valve 40, an aluminum pipe 34 a that constitutes an end of the inlet side pipe 34, and an outlet side pipe 36 are provided.

  The flow rate adjustment valve 40 is provided at a position near the flange 33. The flow rate adjusting valve 40 is a valve in which a flow path (not shown) is formed and a valve body (not shown) is arranged in the flow path. The valve body is displaced in the flow path by driving a step motor (not shown), so that the flow path cross-sectional area inside the flow rate adjustment valve 40 is adjusted.

  The aluminum pipe 34a is a member that configures the inlet side pipe 34 in communication with the inlet side pipe main body 34b. The aluminum pipe 34 a is inserted through the flange 33, is disposed in the auxiliary machine casing 31 and slightly below the flow rate adjustment valve 40, and is connected to the inlet 41 of the flow rate adjustment valve 40 so as to have an upward slope. ing. Thereby, the inlet side pipe 34 composed of the aluminum pipe 34 a and the inlet side pipe main body 34 b forms a flow path communicating from the inlet part 41 of the flow rate adjusting valve 40 to the inside thereof.

  The outlet side pipe 36 is disposed so as to extend in the Y direction inside the auxiliary machine casing 31, and one end portion 36 a thereof is connected to the outlet portion 43 of the flow rate adjusting valve 40 so as to be inclined downward. The other end 36 b of the outlet side pipe 36 is connected to another pipe (not shown) communicating with the inside of the fuel cell casing 21.

  As described above, the inlet side pipe 34 and the outlet side pipe 36 are connected via the flow rate adjusting valve 40, thereby supplying air to the fuel cell stack 22 inside the fuel cell casing 21. 37 is constituted. The air pressurized by a pump (not shown) and flowing into the inlet side pipe 34 as shown by the arrow A1 flows along the inlet side pipe main body 34b to the flange 33 side. Thereafter, the air changes its direction obliquely upward along the gradient of the aluminum pipe 34a as indicated by the arrow A2, and flows into the flow rate adjusting valve 40 from the inlet 41.

  The air that has passed through the flow rate adjusting valve 40 and has flowed out of the outlet portion 43 flows obliquely downward along the gradient of the one end portion 36a of the outlet side pipe 36, as indicated by an arrow A3. The air flows through the outlet side pipe 36 in the Y direction, then flows out from the other end 36b as indicated by the arrow A4, and is further guided to the fuel cell stack 22 by another pipe. The fuel cell stack 22 generates power using oxygen in the air supplied by the air supply pipe 37.

  The operational effects of the fuel cell system 10 described above will be described. First, the aluminum pipe 34a of the inlet side pipe 34 is made of aluminum having a relatively high thermal conductivity, and is formed to have a smaller heat capacity than the flow rate adjustment valve 40. For this reason, when the fuel cell system 10 is at a low temperature, such as when the fuel cell stack 22 is not generating power (when the fuel cell stack 22 is stopped), the aluminum pipe 34a has a higher capacity than the flow control valve 40. Condensation is likely to occur. Therefore, by dew condensation preferentially inside the aluminum pipe 34a during non-power generation, the water vapor contained in the air inside the flow rate adjustment valve 40 is reduced, and the occurrence of condensation in the flow rate adjustment valve 40 and its freezing are suppressed. can do.

  Further, since the aluminum pipe 34a of the inlet side pipe 34 is accommodated in the auxiliary machine casing 31 similarly to the flow rate adjustment valve 40, the aluminum pipe 34a and the flow rate adjustment valve 40 can be arranged close to each other. Become. Therefore, the amount of water vapor contained in the air inside the flow rate adjustment valve 40 can be reliably reduced during non-power generation, and the occurrence of condensation and freezing inside the flow rate adjustment valve 40 can be further suppressed.

  Further, the aluminum pipe 34 a of the inlet side pipe 34 is disposed slightly below the flow rate adjustment valve 40. For this reason, the dew condensation water generated inside the aluminum pipe 34 a can be prevented from flowing toward the flow rate adjustment valve 40. Therefore, it is possible to prevent the condensed water generated inside the aluminum pipe 34a from reaching the flow rate adjusting valve 40 and freezing.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. For example, the elements included in each of the specific examples described above and their arrangement, materials, conditions, shapes, sizes, and the like are not limited to those illustrated, but can be changed as appropriate. Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

DESCRIPTION OF SYMBOLS 10: Fuel cell system 20: Fuel cell unit 22: Fuel cell stack 31: Auxiliary casing 34: Inlet side piping 34a: Aluminum piping (condensation promotion part)
36: Outlet side piping 37: Air supply piping 40: Flow rate adjusting valve

Claims (1)

A fuel cell system that generates power using fuel gas and oxidant gas,
A fuel cell stack that generates power by supplying fuel gas and oxidant gas; and
An air supply pipe that internally forms a flow path for supplying air to the fuel cell stack;
A flow rate adjusting valve that is provided in the air supply pipe and changes an internal flow path cross-sectional area ;
An auxiliary machine casing that houses the flow rate adjusting valve and the dew condensation promoting part inside ,
The air supply pipe has a dew condensation promoting part having a heat capacity smaller than that of the flow rate adjusting valve in at least a part thereof ,
The fuel cell system , wherein the dew condensation promoting part is provided at a position lower than the flow rate adjusting valve .

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