JP5904128B2 - Fuel cell system having a relief valve - Google Patents

Description

  The present invention relates to a fuel cell system having a relief valve, and relates to a technique for suppressing adverse effects on the valve due to the backflow of foreign matter.

  In a fuel cell system, there is known a fuel cell in which a relief valve is provided in a fuel gas supply path for supplying fuel gas to the fuel cell, a gas discharge side of the relief valve is connected to a diluter, and further gas is released to the outside air (Patent Document 1).

JP 2006-294341 A

  Cathode exhaust gas is also discharged to the diluter. The cathode exhaust gas also includes water produced by the reaction of the fuel cell. When the relief valve is not open, gas does not flow from the fuel gas supply path to the diluter, and on the contrary, foreign matters such as moisture may flow back to the relief valve, which may adversely affect the relief valve.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one aspect of the present invention, a fuel cell system having a relief valve is provided. The fuel cell system discharges exhaust gas from the fuel cell, a gas tank for storing fuel gas supplied to the fuel cell, a gas supply pipe connecting the gas tank and the fuel cell, and the fuel cell. A gas exhaust pipe, a pressure reducing valve provided in the gas supply pipe, a relief valve provided between the pressure reducing valve and the fuel cell, and an exhaust gas connecting the exhaust port of the relief valve and the gas exhaust pipe A relief valve, a housing having a valve port and the exhaust port, a valve seat provided in the valve port, a valve body, and a pressure adjusting screw for adjusting a pressure at which the valve body opens. And a gas permeable membrane is provided between at least one of the pressure adjusting screw of the relief valve and the exhaust port and between the stress concentration portion provided on the exhaust tube and the relief valve. . According to the fuel cell system of this aspect, even if a foreign substance tries to enter from the gas exhaust pipe, the gas permeation provided by the gas permeable membrane provided in the exhaust tube or between the pressure adjusting screw of the relief valve and the exhaust port is provided. The membrane makes it possible to prevent foreign matter from entering the contact portion between the valve body and the valve seat.

  In addition, this invention can be implement | achieved with various forms, for example, can be implement | achieved with forms, such as a relief valve other than a fuel cell system.

It is explanatory drawing which shows the fuel cell system concerning 1st Embodiment. It is explanatory drawing which shows the operation | movement at the time of the vehicle stop in this embodiment. It is explanatory drawing which shows typically the relief valve used by this embodiment. It is explanatory drawing which shows the fuel cell system concerning 2nd Embodiment.

First embodiment:
FIG. 1 is an explanatory diagram showing a fuel cell system 10 according to the first embodiment. The fuel cell system of the present embodiment can be used as a power source for vehicles, for example. The fuel cell system 10 includes a fuel cell 100, a gas tank 200, a compressor 300, and a diluter 270. The fuel cell 100 is a cell that generates electric energy by reacting hydrogen with oxygen in the air. In this embodiment, hydrogen is also called “anode gas” and air is also called “cathode gas”. The gas tank 200 is a tank that stores hydrogen supplied to the fuel cell 100. The fuel cell 100 and the gas tank 200 are connected by an anode gas supply pipe 210. The fuel cell 100 is provided with an anode gas exhaust pipe 250 for discharging the anode exhaust gas after the reaction. The compressor 300 collects air in the atmosphere and compresses it. The compressed air is supplied to the fuel cell 100 through the cathode gas supply pipe 310. The fuel cell 100 is provided with a cathode gas exhaust pipe 350 for exhausting the cathode exhaust gas after the reaction. A diluter 270 is provided in the anode gas exhaust pipe 250 and the cathode gas exhaust pipe. The diluter 270 dilutes hydrogen in the anode exhaust gas with the cathode exhaust gas.

  The anode gas supply pipe 210 is provided with a pressure reducing valve 230, a relief valve 400, and a shutoff valve 240 from the gas tank 200 side. The pressure reducing valve 230 adjusts the pressure of hydrogen supplied from the gas tank 200. The relief valve 400 opens when the pressure inside the anode gas supply pipe 210 becomes higher than a set value, and adjusts the pressure so that the pressure inside the anode gas supply pipe 210 does not become too high. The output port of the relief valve 400 is connected to the diluter 270 via the exhaust tube 260. An anode gas filling port 220 for filling the gas tank with the anode gas is provided further upstream of the gas tank 200 in the anode gas supply pipe 210.

  FIG. 2 is an explanatory diagram illustrating an operation when the vehicle is stopped in the present embodiment. The horizontal axis in the figure is time, and the vertical axis is the pressure inside the anode gas supply pipe 210 on the downstream side of the pressure reducing valve 230. When the vehicle is in operation, the pressure reducing valve 230 regulates the pressure in the anode gas supply pipe 210 on the downstream side of the pressure reducing valve 230 to be lower than the pressure regulating valve pressure regulation value upper limit. Further, the shutoff valve 240 is opened, and the anode gas is supplied to the fuel cell 100. When the vehicle is stopped and the operation of the fuel cell 100 is stopped, the shutoff valve is closed, and the supply of the anode gas from the anode gas supply pipe 210 to the fuel cell 100 is stopped. Therefore, the pressure inside the anode gas supply pipe 210 gradually increases. When the pressure inside the anode gas supply pipe 210 becomes equal to or higher than the operating pressure of the relief valve 400, the relief valve 400 is opened, and the pressure inside the anode gas supply pipe 210 does not rise above the operating pressure of the relief valve 400.

  Incidentally, a diluter 270 is provided downstream of the output port of the relief valve 400. A cathode gas exhaust pipe 350 is also connected to the diluter 270. The cathode exhaust gas also contains moisture generated by the reaction of the fuel cell 100. When the relief valve 400 is not in operation, foreign matter such as moisture may flow back through the exhaust tube 260 from the diluter 270 toward the relief valve 400, and the relief valve 400 may malfunction due to the backflowed foreign matter. May occur.

  FIG. 3 is an explanatory view schematically showing a relief valve 400 used in the present embodiment. The relief valve 400 includes a housing 410, a piston 420, a pressure adjusting screw 430, an output port 440, a spring 450, and a gas permeable membrane 460. The housing 410 is a member having a hollow portion 411 and includes an input port 412 and a valve seat 413. The input port 412 is also referred to as a “valve port”. A female screw 414 is cut on the inner wall of the hollow portion 411 on the output port 440 side. The piston 420 is a member disposed in the hollow portion 411 of the housing 410. The piston 420 includes a valve body 421 on the input port 412 side. On the opposite side of the piston 420 from the input port 412, a recess 422 for accommodating the spring 450 is formed. The pressure adjusting screw 430 is a member disposed in the hollow portion 411 of the housing 410. A male screw 431 is cut at the outer edge of the pressure adjusting screw 430. A spring 450 is disposed between the pressure adjusting screw 430 and the recess 422 of the piston 420. The valve body 421 of the piston 420 is pressed against the valve seat 413 by the extension force of the spring 450. By rotating the pressure adjusting screw 430, the interval between the piston 420 and the pressure adjusting screw 430 can be changed, and the pressure at which the valve body 421 opens can be changed. The output port 440 includes a gas permeable membrane 460 on the pressure adjusting screw 430 side. The gas permeable membrane 460 suppresses foreign matter from entering the hollow portion 411 of the housing 410 from the output port 440 side. The output port 440 is a member having a male screw 441 on the outer peripheral portion, and the housing 410 and the output port 440 can be easily separated. Therefore, replacement of the gas permeable membrane 460 is easy.

  In the present embodiment, the inner diameter φB of the output port 440 is preferably larger than the inner diameter φA of the input port 412. Even if the pressure reducing valve 230 breaks down and a large amount of anode gas flows, it can be easily discharged. Further, when the pressure reducing valve 230 fails, an increase in the pressure inside the anode gas supply pipe 210 on the downstream side of the pressure reducing valve 230 can be suppressed.

  In the present embodiment, since the gas permeable membrane 460 is provided, it is possible to prevent foreign matter from entering the hollow portion 411 of the housing 410 from the output port 440 side. In addition, the gas permeable membrane 460 is attached to the output port 440, and the housing 410 and the output port 440 can be easily separated, so that the gas permeable membrane 460 can be easily replaced. As a result, maintenance costs can be reduced.

Second embodiment:
FIG. 4 is an explanatory diagram showing a fuel cell system 11 according to the second embodiment. The fuel cell system 11 according to the second embodiment differs from the fuel cell system 10 according to the first embodiment in the configuration of the exhaust tube. The exhaust tube 260 of the first embodiment directly connects the relief valve 400 and the diluter 270. In contrast, the exhaust tube 280 of the second embodiment is provided with a stress concentration portion 282 in the middle of the exhaust tube 280 and a gas permeable membrane 281 between the stress concentration portion 282 and the relief valve 400. The point to prepare is different. The gas permeable membrane 281 prevents foreign substances such as water from entering the relief valve 400 from the diluter 270. In the stress concentration portion 282, when a foreign substance such as water enters the exhaust tube 280 from the diluter 270 and internal pressure is applied to the exhaust tube 280, the stress concentration portion 282 is deformed and stress is applied to other portions. To prevent. By providing such a stress concentration portion 282, it is possible to prevent the gas permeable membrane from being damaged due to excessive stress. The position of the stress concentration portion 282 does not have to be exactly in the middle of the exhaust tube 280.

  In the second embodiment, even if a foreign substance tries to enter from the diluter 270 toward the relief valve 400, the gas permeable film 281 can prevent the foreign substance from entering. Further, since foreign matter can be blocked by the gas permeable membrane 281, it is difficult to reach the relief valve 400. In addition, when foreign matter enters, it is only necessary to replace the exhaust tube 280 and the gas permeable membrane 281, and it is not necessary to disassemble the relief valve 400, so that maintenance is facilitated.

  The relief valve 400 of the first embodiment may be the same as the relief valve 400 of the first embodiment, and is a relief valve in which the gas permeable membrane 460 is removed from the relief valve 400 of the first embodiment. There may be. In the second embodiment, since the entry of foreign matter can be suppressed by the gas permeable film 281 on the exhaust tube 280, the relief valve 400 may not include the gas permeable film 460.

  The embodiments of the present invention have been described above based on some embodiments. However, the embodiments of the present invention described above are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 10, 11 ... Fuel cell system 100 ... Fuel cell 200 ... Gas tank 210 ... Anode gas supply pipe 220 ... Anode gas filling port 230 ... Pressure reducing valve 240 ... Shut-off valve 250 ... Anode gas exhaust pipe 260 ... Exhaust tube 270 ... Diluter 280 ... Exhaust tube 281 ... Gas permeable membrane 300 ... Compressor 310 ... Cathode gas supply pipe 350 ... Cathode gas exhaust pipe 400 ... Relief valve 410 ... Housing 411 ... Hollow part 412 ... Input port 413 ... Valve seat 414 ... Female screw 420 ... Piston 421 ... Valve body 422 ... Recess 430 ... Pressure adjusting screw 431 ... Male screw 440 ... Output port 441 ... Male screw 450 ... Spring 460 ... Gas permeable membrane φA, φB ... Inner diameter

Claims (1)

A fuel cell system having a relief valve,
A fuel cell;
A gas tank for storing fuel gas supplied to the fuel cell;
A gas supply pipe connecting the gas tank and the fuel cell;
A gas discharge pipe for discharging exhaust gas from the fuel cell;
A pressure reducing valve provided in the gas supply pipe;
A relief valve provided between the pressure reducing valve and the fuel cell;
An exhaust tube connecting the exhaust port of the relief valve and the gas exhaust pipe;
With
The relief valve is
A housing having a valve port and the exhaust port;
A valve seat provided at the valve opening;
The disc,
A pressure adjusting screw for adjusting the pressure at which the valve body opens;
Have
A relief valve in which a gas permeable film is provided between at least one of the pressure adjusting screw and the exhaust port of the relief valve and between the stress concentration portion provided in the exhaust tube and the relief valve. A fuel cell system.

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