JP2008243488A - Fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system capable of suppressing noise caused by opening and closing of an exhaust valve. <P>SOLUTION: The fuel cell system 1 is equipped with a circulation line 50 circulating and supplying hydrogen offgas exhausted from a fuel cell 2 to the fuel cell 2; an exhaust valve 48 exhausting fluid (hydrogen offgas and produced water) in the circulation line 50 to the outside; and a control device 6 controlling the opening and closing of the exhaust valve 48. The control device 6 opens and closes the exhaust valve 48 to exhaust moisture and impurities in the hydrogen offgas to the outside when the fuel cell system 1 is in a normal operation state, and when the fuel cell system 1 is in an operation state in which working sound is lower than that in the normal operation, the control device 6 inhibits the opening and closing of the exhaust valve 48. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a fuel gas circulation system, and more particularly to a fuel cell system including a discharge valve for discharging a fluid containing a fuel off-gas or generated water in the circulation system to the outside.

  Currently, a fuel cell system including a fuel cell that generates power by receiving supply of a fuel gas containing hydrogen and an oxidizing gas containing oxygen as reaction gases has been proposed and put into practical use. For example, the fuel cell system described in Patent Document 1 includes a circulation system that circulates and supplies fuel off-gas discharged from the fuel cell to the fuel cell by a circulation pump.

The fuel off gas in the circulation system contains generated water generated by the electrochemical reaction of the fuel cell. The circulation system is provided with a gas-liquid separator that separates the fuel off-gas and the produced water, and a discharge valve that discharges the separated produced water to the outside is connected to the gas-liquid separator. The discharge valve not only functions as a drain valve, but also functions as an exhaust valve, and discharges impurities in the fuel off-gas together with the fuel off-gas to prevent a decrease in the hydrogen concentration in the circulation system. The discharge valve is a shut valve or the like, and is controlled to be opened and closed by the control device during operation of the fuel cell system.
Japanese Patent Laying-Open No. 2005-302708 (paragraphs 0040-0042)

  By the way, when the discharge valve is opened and closed, a predetermined operating sound (sounding sound) is generated due to a collision between the valve body and the valve seat. In particular, an operating noise is generated when the valve body closes against the valve seat. In a normal operation state in which the fuel cell system is operating at a load higher than a certain level, devices such as an air compressor and a circulation pump are operating at a rotational speed exceeding a certain level. For this reason, the operation sound of the discharge valve is canceled by the operation sound of these devices, and is not easily recognized as noise.

  However, in a state where the operation load of the fuel cell system is small, for example, in an idle state where the load of the compressor and the circulation pump is small and the engine is operating at a low speed, the operation noise of these devices is relatively small. For this reason, the operation noise associated with the opening / closing of the discharge valve is relatively large with respect to the operation sound of the device, and the opening / closing sound of the discharge valve may be a major noise source.

  An object of this invention is to provide the fuel cell system which can suppress the noise by opening and closing of a discharge valve.

  In order to achieve the above object, a fuel cell system of the present invention includes a circulation system that circulates and supplies fuel off-gas discharged from a fuel cell to the fuel cell, a discharge valve that discharges fluid in the circulation system to the outside, and a discharge And a control device for controlling opening and closing of the valve. The control device permits opening / closing of the discharge valve when the fuel cell system is in the normal operation state, and prohibits opening / closing of the discharge valve when the fuel cell system is in the first operation state where the operation noise is lower than that in the normal operation state. .

  According to this configuration, when the operating sound other than the opening / closing sound of the discharge valve is small, the opening / closing of the discharge valve is not performed. Therefore, the noise accompanying opening and closing of the discharge valve can be suppressed without providing a silencer structure in the discharge valve. On the other hand, since the opening and closing of the discharge valve is permitted during normal operation, fluid (for example, fuel offgas containing impurities or moisture or generated water) can be discharged, and fuel offgas suitable for the fuel cell is circulated. Can supply.

  According to one aspect of the present invention, the first operating state may be an idle state of the fuel cell system.

  If it does in this way, the noise by opening and closing of a discharge valve can be suppressed in the idle state where operation sound is relatively small. Further, in the idle state where the output of the fuel cell is small, the fuel concentration in the fuel off-gas does not have to be higher than in the normal operation state, so that the influence on the output of the fuel cell can also be suppressed without opening the discharge valve. .

  According to one aspect of the present invention, when the control device opens the discharge valve for the first time after shifting from the idle state to the normal operation state, the control device opens the discharge valve so that more fluid is discharged than during normal opening. Good.

  In this way, impurities or moisture accumulated without being discharged during the idle state can be quickly discharged from the circulation system to the outside after shifting to the normal operation state.

  According to one aspect of the present invention, when the control device opens the discharge valve for the first time after shifting from the idle state to the normal operation state, the control device discharges so that the opening time of the discharge valve is longer than that during normal opening. The valve should be opened.

  In this way, more fluid can be discharged after the transition to the normal operating state than when the valve is normally opened. Therefore, impurities or moisture accumulated without being discharged during the idle state can be quickly discharged outside after shifting to the normal operation state.

  According to one aspect of the present invention, the circulation system has a gas-liquid separator that separates and stores moisture from the fuel off-gas, and the discharge valve fuels the moisture stored in the gas-liquid separator when the valve is opened. It is good to discharge to the outside together with off-gas.

  Another fuel cell system of the present invention for achieving the above object includes a circulation system that circulates and supplies fuel off-gas discharged from the fuel cell to the fuel cell, a discharge valve that discharges fluid in the circulation system to the outside, And a control device that controls opening and closing of the discharge valve. The discharge valve includes a flow path that communicates the inside and outside of the circulation system, a valve seat, a valve body that contacts the valve seat to close the flow path and is spaced apart from the valve seat to open the flow path; And a drive unit that moves the valve body with a predetermined stroke with respect to the valve seat. The control device controls the drive unit so that the valve body is moved with a stroke shorter than that in the normal operation state when the fuel cell system is in the first operation state in which the operation noise is smaller than that in the normal operation state.

  According to this configuration, in the first operating state in which the operation sound is relatively low, the kinetic energy of the valve body is small because the stroke of the valve body is shorter than in the normal operating state. Therefore, the collision sound between the valve body and the valve seat can be reduced, and noise due to opening and closing of the discharge valve can be suppressed.

  According to the fuel cell system of the present invention, noise due to opening and closing of the discharge valve can be suppressed.

  Hereinafter, a fuel cell system according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a system configuration diagram of the fuel cell system 1. The fuel cell system 1 is an on-vehicle power generation system for a fuel cell vehicle. The fuel cell system 1 is applied to a power generation system for any moving body such as a ship, an aircraft, a train, or a walking robot, and further to a stationary power generation system used as a power generation facility for a building (house, building, etc.). Is possible.

  As shown in FIG. 1, the fuel cell system 1 includes a fuel cell 2, an oxygen gas piping system 3, a fuel gas piping system 4, and a control device 6.

  The fuel cell 2 is made of, for example, a solid polymer electrolyte type and has a stack structure in which a large number of single cells are stacked. The fuel cell 2 generates electric power upon receiving supply of oxygen gas and fuel gas. Further, water is generated on the air electrode side of the fuel cell 2 by this electrochemical reaction. A part of this generated water can move to the fuel electrode side through the electrolyte membrane of the single cell. Supply and discharge of oxygen gas and fuel gas to and from the fuel cell 2 are performed by an oxygen gas piping system 3 and a fuel gas piping system 4.

  Oxygen gas and fuel gas are collectively referred to as reaction gas. In particular, oxygen gas and fuel gas discharged from the fuel cell 2 are referred to as oxygen off gas and fuel off gas, respectively, and these are collectively referred to as reaction off gas. The fuel gas is a gas containing hydrogen. Hereinafter, air will be described as an example of oxygen gas, and hydrogen gas will be described as an example of fuel gas. The fuel off gas is referred to as hydrogen off gas.

  The oxygen gas piping system 3 includes a humidifier 30, a supply flow path 31, a discharge flow path 32, an exhaust flow path 33, and a compressor 34. The compressor 34 is provided at the upstream end of the supply flow path 31. Air in the atmosphere (oxygen gas) taken in by the compressor 34 flows through the supply flow path 31, is pumped to the humidifier 30, is humidified by the humidifier 30, and is supplied to the fuel cell 2. The oxygen off gas discharged from the fuel cell 2 flows through the discharge channel 32 and is introduced into the humidifier 30, and then flows through the exhaust channel 33 and is discharged to the outside.

The fuel gas piping system 4 has a hydrogen tank 40, a supply channel 41 and a circulation channel 42.
The hydrogen tank 40 is a hydrogen supply source that stores high-pressure (for example, 70 MPa) hydrogen gas. Instead of the hydrogen tank 40, a reformer that generates a hydrogen-rich reformed gas from a hydrocarbon-based fuel, a high-pressure gas tank that stores the reformed gas generated by the reformer in a high-pressure state, and Can also be employed as a hydrogen source. Moreover, it may replace with the hydrogen tank 40 and may employ | adopt the tank which has a hydrogen storage alloy.

  The supply flow path 41 is a flow path for supplying the hydrogen gas in the hydrogen tank 40 to the fuel cell 2 and includes a main flow flow path 41a and a mixing flow path 41b with the junction A as a boundary. A shut valve 43, a regulator 44, and an injector 45 are provided in the main flow channel 41a. The shut valve 43 functions as a main valve of the hydrogen tank 40 and blocks or allows the supply of hydrogen gas from the hydrogen tank 40 to the fuel cell 2 side. The regulator 44 is, for example, a mechanical pressure reducing valve, and reduces the gas pressure of hydrogen gas to a preset secondary pressure. The injector 45 is an electromagnetically driven on-off valve, and adjusts the flow rate and gas pressure of hydrogen gas supplied to the mixing channel 41b side with high accuracy.

  The circulation flow path 42 is a return pipe for returning the hydrogen off gas discharged from the hydrogen gas outlet of the fuel cell 2 to the supply flow path 41. The circulation channel 42 is provided with a hydrogen pump 46 that pressurizes the hydrogen off-gas in the circulation channel 42 and pumps it to the junction A. At the merge point A, the new hydrogen gas from the hydrogen tank 40 and the hydrogen off gas from the hydrogen pump 46 merge, and the mixed hydrogen gas after the merge flows through the mixing channel 41b and is supplied to the fuel cell 2. As a result, the remaining hydrogen in the hydrogen off-gas is supplied again to the power generation of the fuel cell 2.

  The circulation channel 42 is connected to a discharge channel 49 via a gas-liquid separator 47 and an exhaust / drain valve 48 provided on the upstream side of the hydrogen pump 46. The hydrogen off-gas flowing through the circulation channel 42 contains water and nitrogen gas of product water that has permeated from the electrolyte membrane to the fuel electrode side, although the amount is small compared to the amount of hydrogen off-gas. The gas-liquid separator 47 separates the liquid (water) and gas (hydrogen offgas) in the hydrogen offgas, and temporarily stores the separated water. The stored water is discharged from the exhaust / drain valve 48 to the discharge channel 49 and discharged to the outside. Further, part of the hydrogen off-gas after the moisture recovery is also discharged from the exhaust drain valve 48 to the discharge channel 49 and discharged to the outside.

  As described above, the exhaust drain valve 48 not only functions as a drain valve that discharges moisture to the outside as a fluid flowing in the circulation system 50 but also functions as an exhaust valve that discharges hydrogen off-gas containing impurities to the outside. By opening the exhaust / drain valve 48, the generated water accumulated in the gas-liquid separator 47 can be discharged, and the hydrogen concentration in the hydrogen off-gas can be increased. The specific structure and control example of the exhaust / drain valve 48 will be described later.

  The downstream end of the discharge channel 49 may be opened to the atmosphere as it is, but may be connected to a diluter or an exhaust channel 33 (not shown). The circulation system 50 is a system in which the circulation channel 42, the mixing channel 41, and the gas channel in the fuel cell 2 are connected in order, and hydrogen off-gas is circulated and supplied to the fuel cell 2 again.

  The control device 6 is configured as a microcomputer having a CPU, ROM, and RAM therein. The CPU executes a desired calculation according to the control program and performs various processes and controls such as opening / closing control of an exhaust / drain valve 48 described later. 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 device 6 detects an operation amount of an acceleration operation device (accelerator pedal or the like) provided in the vehicle, and controls information such as an acceleration request value (for example, a required power generation amount from a load device that consumes power such as a traction motor). In response, the operation of various devices in the system 1 is controlled. In addition to the traction motor, the load device includes a compressor 34, a hydrogen pump 46, and a motor for auxiliary devices such as a refrigerant circulation pump (not shown) necessary for operating the fuel cell 2, and vehicle running. Actuators used in various devices (wheel control units, steering devices, suspension devices, etc.), air conditioners, lighting and audio.

  Detection information of the current sensor 2 a that detects the amount of power generated by the fuel cell 2 is input to the control device 6. In addition, detection information of a sensor that detects the pressure, temperature, flow rate, and the like of a fluid flowing through each piping system, detection information of a sensor that detects an outside air temperature, and the like are input. The control device 6 drives and controls the compressor 34, the shut valve 43, the injector 45, and the like based on the required power generation amount and the detection information of each sensor, and causes the fuel cell 2 to react with the flow rate and pressure corresponding to the required power generation amount. And a purge operation in the circulation system 50 is performed by controlling the exhaust / drain valve 48.

FIG. 2 is a cross-sectional view of the exhaust / drain valve 48.
The exhaust / drain valve 48 (discharge valve) is an electromagnetically driven on / off valve that operates in response to a control signal from the control device 6 and intermittently discharges the fluid in the circulation system 50 to the discharge channel 49. The exhaust / drain valve 48 has an angle valve structure and includes a valve body 61, a valve seat 61 d, a valve body 62, and a diaphragm 63.

  In the valve body 61, an inflow path 61a, an outflow path 61b, and a valve chamber 61c that connects the inflow path 61a and the outflow path 61b are formed. The inflow path 61 a communicates with the circulation flow path 42 through the gas-liquid separator 47, and the outflow path 61 b communicates with the outside through the discharge flow path 49. That is, the inflow path 61a, the outflow path 61b, and the valve chamber 61c function as a flow path 61e that connects the inside of the circulation system 50 to the outside. The valve seat 61d is formed on the bottom surface of the valve chamber 61c and has an opening that communicates with the outflow passage 61b.

  The valve body 62 is disposed in the valve chamber 61c, and is provided so as to be able to advance and retract with a predetermined stroke in the direction of the axis XX. The valve body 62 has a seal rubber 62a at the end on the valve seat 61d side. The valve body 62 closes the opening of the valve seat 61d by the seal rubber 62a coming into contact with the valve seat 61d at a position on one end side of the forward / backward movement range (closed position shown in FIG. 2). Thereby, the flow path 61e is closed. On the other hand, when the valve body 62 moves to a position where the seal rubber 62a is separated from the valve seat 61d, the opening of the valve seat 61d is opened and the flow path 61e is opened. The seal rubber 62a is made of EPDM, for example, but may be omitted.

  The diaphragm 63 is disposed between the outer surface of the valve body 62 and the edge of the valve chamber 61c, and is configured to follow the movement of the valve body 62. The inside of the valve chamber 61c and the housing 69 are hermetically separated by the diaphragm 63. Thereby, the fluid from the valve chamber 61c side is prevented from entering the gap between the plunger 64 and the sleeve 67.

  The plunger 64 has a valve body 62 fixed to the tip thereof, and slides in the direction of the axis XX along the inner peripheral surface of the sleeve 67. The plunger 64 is urged in a direction away from the center core 68 by a spring 64a. The urging force of the spring 64a is set to a magnitude that does not open even when the diaphragm 63 receives the primary pressure when the valve 64 is closed. The plunger 64, the coil 65, and the iron core 66 are housed in a housing 69, and constitute a drive unit of a solenoid type actuator for reciprocating the valve body 62 with a predetermined stroke in the direction of the axis XX. Power supply to the coil 65 of the drive unit is controlled by the control device 6.

  The exhaust / drain valve 48 is basically used in two positions, “open” and “closed”, by turning on and off the current supplied to the coil 65. Specifically, when the power supply to the coil 65 is turned on, the iron core 66 is magnetized, the plunger 64 moves against the spring 64a, and the valve body 62 is separated from the valve seat 61d. As a result, the exhaust / drain valve 48 is opened, and the fluid is allowed to be discharged into the discharge channel 49. On the other hand, when the power supply to the coil 65 is off, the valve body 62 contacts the valve seat 61d by the biasing force of the spring 64a. As a result, the exhaust / drain valve 48 is closed, and the discharge of fluid to the discharge channel 49 is blocked. Note that the fluid discharge amount and discharge timing are controlled by changing the opening time and opening / closing timing of the exhaust / drain valve 48.

  The exhaust / drain valve 48 having such a configuration generates a predetermined operating sound when opening and closing. The main sound source of the operating sound is a collision sound (sounding sound) when the seal rubber 62a contacts the valve seat 61d when the valve is closed. The magnitude of this collision sound is a magnitude corresponding to the stroke of the valve element 62 from the “open” position to the “closed” position, that is, a magnitude corresponding to the speed based on the potential energy at the open position of the valve element 62. . Even when the valve body 62, the plunger 64, or the like collides with the stopper when the valve is opened, the exhaust / drain valve 48 generates an operating noise.

  Here, during operation of the fuel cell system 1, operating noise is generated from devices such as the compressor 34 and the hydrogen pump 46 in addition to the exhaust drain valve 48. When these devices are operating at a load exceeding a certain level according to the required power generation amount, that is, when the fuel cell system 1 is in a normal operation state, the operation sound of the exhaust drain valve 48 is smaller than the operation sound of these devices. Therefore, there is no problem as a noise source. Note that the normal operation state is a state where the power generation amount of the fuel cell 2 exceeds, for example, 15A.

  However, in the operating state of the fuel cell system 1, the required power generation amount (for example, 15 A or less) of the fuel cell 2 is small, and the loads on the compressor 34 and the hydrogen pump 46 are sometimes small. Such an operating state is when the fuel cell system 1 is in an idle state, and in a vehicle, there is no operation amount of the accelerator pedal. In the idle state, the motors of the devices such as the compressor 34 and the hydrogen pump 46 operate at a low speed, and the operating noise is lower than that in the normal operation state. Therefore, when the exhaust / drain valve 48 is opened / closed in the idle state, the operation sound accompanying the opening / closing becomes the main noise source of the operation sound of the entire fuel cell system 1.

  In this embodiment, paying attention to such an operation sound, the opening / closing of the exhaust / drain valve 48 is controlled as follows. First, when the fuel cell system 1 is in a normal operation state, the control device 6 permits opening / closing of the exhaust / drain valve 48 and performs a purge operation for opening / closing the exhaust / drain valve 48 at a predetermined cycle. As a result, the hydrogen concentration in the hydrogen off-gas can be increased, or the generated water accumulated in the gas-liquid separator 47 can be discharged. On the other hand, when the fuel cell system 1 is in the idle state, the control device 6 prohibits the opening and closing of the exhaust drain valve 48 and does not perform the purge operation. Thereby, since the operation sound of the exhaust / drain valve 48 is not generated, the operation sound can be reduced as the whole fuel cell system 1.

  Here, the determination of whether the fuel cell system 1 is in a normal operation state or an idle state may be made based on detection information of the current sensor 2a, for example. However, instead of monitoring the amount of power generated by the fuel cell 2, other methods such as directly monitoring the rotational speed of a motor such as the compressor 34 or the hydrogen pump 46, or monitoring the opening of the accelerator pedal are used. The operating state of the fuel cell system 1 may be determined.

  When the fuel cell system 1 shifts from the idle state to the normal operation state, the control device 6 resumes the purge operation of the exhaust drain valve 48. When the exhaust drain valve 48 is opened for the first time after this transition, the control device 6 opens the exhaust drain valve 48 so that the amount of fluid (hydrogen offgas or stored product water) discharged is larger than when the valve is normally opened. It is good to open the valve. As the method, for example, the opening time of the exhaust / drain valve 48 is lengthened so that the valve opening time becomes longer than the normal valve opening time in the normal operation state. By doing so, more generated water and hydrogen off-gas can be discharged than during normal valve opening, so that impurities in the generated water and hydrogen off-gas accumulated without being discharged during the idle state can be quickly discharged.

  Note that the opening time may be lengthened not only for one valve opening operation immediately after the transition to the normal operation state but also for a predetermined period (a plurality of valve opening operations) immediately after the transition to the normal operation state. The predetermined period may be varied so as to increase the open time according to the amount of water accumulated during the idle state. Also, instead of increasing the opening time in one valve opening operation, the closing time is shortened and the ratio of the opening time per unit time is increased, so that the amount of fluid discharged per unit time can be increased. Good.

  As described above, according to the fuel cell system 1 of the present embodiment, the opening / closing of the exhaust / drain valve 48 is prohibited when the operation sound (idle state) is lower than the normal operation state. Therefore, noise based on opening / closing of the exhaust / drain valve 48 can be suppressed without providing the exhaust / drain valve 48 with a silencing structure. Further, in the idle state, the hydrogen concentration in the hydrogen off-gas does not have to be higher than in the normal operation state, so that the influence on the output of the fuel cell 2 can be suppressed without opening the exhaust / drain valve 48. Furthermore, since the exhaust drain valve 48 is opened and closed during the normal operation state, the hydrogen off-gas in the circulation system 50 can be brought into a state suitable for the power generation of the fuel cell 2.

<Modification>
Hereinafter, modifications of the embodiment will be described. Description of the same parts as those in the above embodiment will be omitted, and only different parts will be described.

<First Modification>
Instead of prohibiting the opening / closing of the exhaust / drain valve 48 in the idle state, this may be allowed. In this case, the operation sound of the exhaust / drain valve 48 may be reduced by performing control to change the stroke of the valve body 62. As this control method, it is preferable to use duty control that changes the duty ratio of the pulsed excitation current supplied to the coil 65 of the exhaust / drain valve 48. Here, the duty ratio is obtained by dividing the ON time of the pulsed excitation current by the switching period obtained by adding the ON time and the OFF time of the pulsed excitation current. By the duty control, the stroke of the valve body 62 can be switched in multiple stages or continuously (non-stage).

  Therefore, the control device 6 controls the opening / closing of the exhaust / drain valve 48 so that the stroke of the valve element 62 is shorter than that in the normal operation state in the idle state. Thereby, since the kinetic energy of the valve body 62 when colliding with the valve seat 61d becomes smaller than that in the normal operation state, the collision sound becomes smaller than in the normal operation state. Therefore, according to this modification, not only can the noise be suppressed as a whole system in the idle state, but also impurities in the water and hydrogen off-gas can be discharged.

  The stroke of the valve body 62 in the idle state is such that the collision sound between the valve body 62 and the valve seat 61d is approximately the same or smaller than the operation sound of the compressor 34, the hydrogen pump 46, etc. in the low rotation state. It should be set to a size that does not cause a problem as a noise source.

<Second Modification>
As the exhaust / drain valve 48, an electric valve using a step motor as a drive unit may be used instead of the solenoid valve using a solenoid as a drive unit. Even if the step motor is used to control the length of the stroke of the valve element 62 to be longer when the idling state is set than the normal operation state, the same effect as that of the first modification can be obtained. .

<Third Modification>
The exhaust / drain valve 48 may perform only one of exhaust and drain. For example, in the case where a drain valve that discharges moisture separated by the gas-liquid separator 47 to the outside and an exhaust valve that discharges hydrogen off-gas in the circulation flow path 42 together with impurities are provided separately. The open / close control similar to that of the exhaust / drain valve 48 may be performed. That is, when the fuel cell system 1 is in the idle state, the drain valve and the exhaust valve may be prohibited from opening and closing, or the stroke of the valve body may be shortened. By doing so, noise accompanying opening and closing of the drain valve and the exhaust valve can be suppressed. In such a configuration, the drain valve is connected to the gas-liquid separator 47 in the same manner as the exhaust drain valve 48. On the other hand, the exhaust valve is interposed in a purge path branched and connected to the circulation flow path 42.

It is a block diagram which shows the principal part of the fuel cell system which concerns on embodiment. It is sectional drawing of the discharge valve which concerns on embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Fuel cell system, 2: Fuel cell, 6: Control apparatus, 42: Circulation flow path, 47: Gas-liquid separator, 48: Exhaust drain valve (discharge valve), 50: Circulation system, 61c: Valve chamber, 61d : Valve seat, 61e: flow path, 62: valve body, 64: plunger, 65: coil (part of the drive unit), 66: iron core

Claims (6)

A circulation system that circulates and supplies fuel off-gas discharged from the fuel cell to the fuel cell;
A discharge valve for discharging the fluid in the circulation system to the outside;
In a fuel cell system comprising a control device for controlling opening and closing of the discharge valve,
The control device permits opening and closing of the discharge valve when the fuel cell system is in a normal operation state, and controls the discharge valve when the fuel cell system is in a first operation state where the operation noise is lower than that in the normal operation state. Fuel cell system that prohibits opening and closing.   The fuel cell system according to claim 1, wherein the first operation state is an idle state of the fuel cell system.   The control device, when opening the discharge valve for the first time after shifting from the idle state to the normal operation state, opens the discharge valve so that more fluid is discharged than during normal valve opening. Item 3. The fuel cell system according to Item 2.   The control device, when opening the discharge valve for the first time after shifting from the idle state to the normal operation state, opens the discharge valve so that the valve opening time is longer than that during normal valve opening. Item 3. The fuel cell system according to Item 2. The circulation system has a gas-liquid separator that separates and stores moisture from the fuel off-gas,
The fuel cell system according to any one of claims 1 to 4, wherein the discharge valve discharges the water stored in the gas-liquid separator to the outside together with the fuel off-gas when the valve is opened. A circulation system that circulates and supplies fuel off-gas discharged from the fuel cell to the fuel cell;
A discharge valve for discharging the fluid in the circulation system to the outside;
In a fuel cell system comprising a control device for controlling opening and closing of the discharge valve,
The discharge valve is
A valve seat,
A flow path communicating between the inside of the circulation system and the outside;
A valve body that contacts the valve seat to close the flow path and is spaced from the valve seat to open the flow path;
A drive unit that moves the valve body with a predetermined stroke with respect to the valve seat;
When the fuel cell system is in the first operating state in which the operation noise is lower than that in the normal operating state, the drive unit moves the valve body with a shorter stroke than in the normal operating state. Control the fuel cell system.