JP2019125462A - Fuel cell system - Google Patents

Abstract

To prevent an error in a detection result by a pressure sensor.SOLUTION: A fuel cell system comprises an air pressure adjustment valve 65, a diluter, a water storage tank, and a pressure sensor 68. The fuel cell system further comprises: a first air exhaust passage 69 which connects an outlet of a cathode in a fuel cell stack to the air pressure adjustment valve 65; and a second air exhaust passage 70 which connects the air pressure adjustment valve 65 to the diluter. The first air exhaust passage 69 includes a guide member 71 and a metal pipe 73. The pressure sensor 68 is arranged on the metal pipe 73. Cathode exhaust gas discharged from the outlet of the cathode flows through the metal pipe 73. In a circulation direction of the cathode exhaust gas, an insulation member is provided on both sides of the metal pipe 73. The metal pipe 73 is electrically connected to an earth.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel cell system.

  The fuel cell system includes a fuel cell stack that generates electric power by a chemical reaction between a fuel gas and an oxidant gas, and a flow path through which the fuel gas and the oxidant gas flow. The fuel gas and the oxidant gas are supplied to the fuel cell stack at a predetermined pressure, and in order to detect the pressure, a pressure sensor is provided in the flow path (see, for example, Patent Document 1).

JP, 2017-54609, A

  By the way, the flow path is configured by mixing metal piping and insulating members such as resin members. The metal pipe may be charged due to the use of a fuel cell stack or the like. At this time, when the insulating members are disposed on both sides of the metal pipe in the flow direction of the gas flowing through the metal pipe, the metal pipe is maintained in a charged state. When the pressure sensor is installed in the metal pipe, the detection result of the pressure sensor may cause an error (drift in the output value of the pressure sensor) due to the influence of charging.

  An object of the present invention is to provide a fuel cell system capable of suppressing the occurrence of an error in the detection result of a pressure sensor.

  A fuel cell system that solves the above problems includes a fuel cell stack, a gas supplied to the fuel cell stack, or a metal pipe through which the gas discharged from the fuel cell stack flows, and a gas flowing through the metal pipe. The first insulating member disposed upstream of the metal pipe in the direction, the second insulating member disposed downstream of the metal pipe in the flow direction of the gas flowing through the metal pipe, and the metal pipe And a pressure sensor for detecting the pressure of the gas flowing through the metal pipe, wherein the metal pipe is electrically connected to the ground.

  By electrically connecting the metal pipe to the ground, when the metal pipe is charged, a current flows between the metal pipe and the ground. The release of the charge carried by the metal pipe prevents the metal pipe from being maintained in a charged state. Therefore, it is possible to suppress the occurrence of an error in the detection result of the pressure sensor due to the influence of charging of the metal pipe.

  In the fuel cell system, the fuel cell stack includes a plurality of fuel cells and two metal plates holding the plurality of fuel cells therebetween, one of the two metal plates being The metal piping which is grounded may be electrically connected to the metal plate which is grounded.

According to this, the metal pipe can be electrically connected to the ground by electrically connecting the grounded metal plate and the metal pipe.
In the fuel cell system, the metal pipe has a flange, and the first insulating member is inserted, and a metal first bolt fastened to the grounded metal plate is inserted, and the flange is inserted. A second metal bolt fastened to the first insulating member, and a jumper wire connecting the first bolt and the second bolt may be provided.

  The first bolt passes through the first insulating member and is fastened to the grounded metal plate, thereby fixing the first insulating member to the metal plate. The first bolt is electrically connected to the metal plate by being fastened to the metal plate. The second bolt penetrates the flange of the metal pipe and is fastened to the first insulating member, thereby fixing the metal pipe to the first insulating member. The second bolt is electrically connected to the metal pipe by inserting the flange of the metal pipe. The metal pipe can be electrically connected to the ground by connecting the first bolt and the second bolt with a jumper wire. Since the bolt for attaching the first insulating member and the metal pipe can be used as a current path, the metal pipe can be easily electrically connected to the ground.

In the fuel cell system, the jumper wire may include a resistor.
According to this, by providing the resistor in the jumper wire, it is possible to prevent a short circuit between the fuel cell and the ground by the jumper wire.

In the fuel cell system, the metal pipe may flow a gas including air discharged from the fuel cell stack.
When power is generated by the fuel cell stack, water is produced. Air discharged from the fuel cell stack contains charged water. For this reason, the metal piping through which the gas containing the air discharged from the fuel cell stack flows tends to be charged. As described above, by electrically connecting a metal pipe that is easy to be charged to the ground, even with a pressure sensor installed in a metal pipe that is easy to be charged, detection results with less error can be obtained.

  According to the present invention, the occurrence of an error in the detection result of the pressure sensor can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of a fuel cell system. The figure which shows a fuel cell stack typically. The schematic diagram which shows the connection aspect of a fuel cell stack and a 1st air discharge flow path.

Hereinafter, an embodiment of a fuel cell system will be described. The fuel cell system of the present embodiment is mounted on a vehicle such as a passenger car or an industrial vehicle (for example, a forklift).
As shown in FIGS. 1 and 2, the fuel cell system 10 includes a fuel cell stack 20. The fuel cell stack 20 includes a plurality of fuel cells 21, a total plus terminal 22, and a total minus terminal 23. The plurality of fuel cells 21 are provided side by side between the total plus terminal 22 and the total minus terminal 23. The fuel cell 21 of the present embodiment is a polymer electrolyte fuel cell.

  The fuel cell stack 20 includes two metal plates 24 and 26 provided at the end and two resin members 27 and 31. The two resin members 27 and 31 and the two metal plates 24 and 26 sandwich the total plus terminal 22, the total minus terminal 23, and the fuel cell 21. The resin member 27 is disposed between the total minus terminal 23 and the metal plate 24 to insulate them from each other. The resin member 31 is disposed between the total plus terminal 22 and the metal plate 26, and insulates both. Although illustration is omitted, through bolts are inserted through the two metal plates 24 and 26, and the two metal plates 24 and 26 are given a restraining force in a direction approaching each other. Thus, the fuel cell 21 is held by the two metal plates 24 and 26.

  Of the two metal plates 24 and 26, the metal plate 24 adjacent to the resin member 27 is grounded (connected to the ground). In the present embodiment, the frame F of the vehicle is grounded (reference potential), and the metal plate 24 is electrically connected to the frame F. As the frame F, for example, a panel that accommodates the fuel cell system 10 can be mentioned. It can be said that the metal plate 24 is body earthed.

  The fuel cell stack 20 generates electricity by the chemical reaction between the fuel gas supplied to the anode and the oxidant gas supplied to the cathode. The fuel cell stack 20 of this embodiment generates electricity using hydrogen gas as fuel gas and oxygen in the air as oxidant gas.

Next, a hydrogen gas supply and discharge system for supplying hydrogen gas to the fuel cell stack 20 and discharging hydrogen gas from the fuel cell stack 20 will be described.
As shown in FIG. 1, the fuel cell system 10 includes a hydrogen tank 40 in which hydrogen gas is stored, and an injector 41 for adjusting the flow rate of hydrogen gas supplied from the hydrogen tank 40 to the fuel cell stack 20. Prepare. The fuel cell stack 20 includes a first hydrogen supply flow path 42 connecting the hydrogen tank 40 and the injector 41, and a second hydrogen supply flow connecting the injector 41 and the anode inlet Ai of the fuel cell stack 20. And a road 43. The hydrogen tank 40 has a cylindrical cross section and stores high pressure hydrogen gas. The injector 41 is an electromagnetic drive type on-off valve whose valve body is electromagnetically driven.

  The fuel cell system 10 includes a gas-liquid separator 44 to which an anode exhaust gas is supplied, a hydrogen circulation pump 45, and an anode pressure sensor 46. The fuel cell system 10 includes a first hydrogen discharge passage 47 connecting the outlet Ae of the anode of the fuel cell stack 20 to the gas-liquid separator 44, and a gas-liquid separator 44 connecting the hydrogen circulation pump 45. And 2. a hydrogen discharge channel 48. The anode exhaust gas is a gas containing hydrogen gas that has not reacted in the fuel cell stack 20 and water. The gas-liquid separator 44 separates the anode exhaust gas into hydrogen gas and water. The hydrogen circulation pump 45 circulates the hydrogen gas by returning the hydrogen gas separated from the anode exhaust gas by the gas-liquid separator 44 to the second hydrogen supply channel 43. The anode pressure sensor 46 is installed in the second hydrogen discharge passage 48 and detects the pressure of the hydrogen gas flowing through the second hydrogen discharge passage 48.

Next, supply of air to the fuel cell stack 20 and an air supply and discharge system relating to discharge of air from the fuel cell stack 20 will be described.
The fuel cell system 10 includes a compressor 61 which sucks air in the atmosphere and discharges compressed air, and an intercooler 62 which cools the air discharged from the compressor 61. The fuel cell stack 20 includes a first air supply flow path 63 connecting the compressor 61 and the intercooler 62, and a second air supply flow path 64 connecting the intercooler 62 and the cathode inlet Ci of the fuel cell stack 20. And. The compressor 61 is an electric compressor driven by an electric motor. The intercooler 62 is a heat exchange unit that individually includes a circulation unit in which the air flows and a circulation unit in which the refrigerant flows, and cools the air by heat exchange between the air and the refrigerant.

  The fuel cell system 10 includes an air pressure regulating valve 65, a diluter 66, a water storage tank 67, a pressure sensor 68, and the control device 11. The fuel cell system 10 includes a first air discharge flow path 69 connecting the outlet Ce of the cathode of the fuel cell stack 20 and the air pressure regulating valve 65, and a second air connecting the air pressure regulating valve 65 and the diluter 66. And a discharge flow path 70. The air pressure adjusting valve 65 adjusts the pressure of the cathode exhaust gas by changing the flow passage cross-sectional area. The cathode exhaust gas is a gas containing air discharged from the fuel cell stack 20 and moisture. The air discharged from the fuel cell stack 20 contains oxygen that has not reacted in the fuel cell stack 20. The air pressure regulating valve 65 is controlled by the controller 11. The pressure of the air supplied to the fuel cell stack 20 is adjusted by adjusting the pressure of the cathode exhaust gas. The air pressure regulating valve 65 of the present embodiment is made of resin. Note that the air pressure regulating valve 65 made of resin indicates at least that whose exterior is made of resin.

  The diluter 66 functions as a gas-liquid separator. The diluter 66 separates the cathode exhaust gas into oxygen and water. The diluter 66 is supplied with water separated from the anode exhaust gas by the gas-liquid separator 44 and hydrogen gas, in addition to the cathode exhaust gas. The hydrogen gas supplied to the diluter 66 is diluted by air and discharged out of the fuel cell system 10. The water separated by the diluter 66 is stored in the water storage tank 67.

  The pressure sensor 68 is installed in the first air discharge passage 69 and detects the pressure of the cathode exhaust gas flowing through the first air discharge passage 69. The detection result of the pressure sensor 68 is output to the control device 11. The controller 11 controls the air pressure regulating valve 65 based on the detection result of the pressure sensor 68.

Next, the connection between the fuel cell stack 20 and the first air discharge channel 69, and the pressure sensor 68 installed in the first air discharge channel 69 will be described in detail.
As shown in FIG. 3, the metal plate 24 includes a through hole 25 penetrating in the thickness direction. The resin member 27 includes a plate-like main body 28 and a protrusion 29 protruding from the main body 28 in the thickness direction of the main body 28. The protrusion 29 is shaped to be insertable into the through hole 25. The resin member 27 includes a flow hole 30 penetrating the resin member 27. The through hole 30 passes through the projecting portion 29 and the protruding portion of the projecting portion 29 in the main body 28. The flow holes 30 serve as the outlet Ce of the cathode.

  The first air discharge flow path 69 includes a guiding member 71 and a metal pipe 73. The guide member 71 is made of resin and is a cylindrical member. The induction member 71 is disposed between the metal plate 24 and the metal pipe 73. The guiding member 71 includes a flow passage 72 communicating with the flow hole 30. The guide member 71 is fixed to the metal plate 24 such that the flow passage 72 and the flow hole 30 communicate with each other. The induction member 71 is provided to guide the cathode exhaust gas to the metal pipe 73 by changing the flow direction of the cathode exhaust gas.

  The metal pipe 73 is disposed in communication with the guiding member 71. The metal pipe 73 is provided with a flange 74. The flange 74 is disposed to overlap with the guide member 71. Further, in the metal pipe 73, an end opposite to the end where the flange 74 is provided is connected to the air pressure regulating valve 65. In the air pressure regulating valve 65, the portion in contact with the metal pipe 73 is made of resin, and it can be said that the air pressure regulating valve 65 and the metal pipe 73 are insulated. The second air discharge passage 70 connected to the air pressure regulating valve 65 is a rubber hose.

  The cathode exhaust gas discharged from the outlet Ce of the cathode flows through the metal pipe 73. A guiding member 71 as a first insulating member is disposed upstream of the metal pipe 73 in the flow direction of the cathode exhaust gas. An air pressure adjusting valve 65 as a second insulating member is disposed downstream of the metal pipe 73 in the flow direction of the cathode exhaust gas. Therefore, insulating members are provided on both sides of the metal pipe 73 in the flow direction of the cathode exhaust gas.

  The pressure sensor 68 is installed in the metal pipe 73. The pressure sensor 68 includes a metal housing 81, a pressure receiving portion 82, and an introduction path 83 for introducing the pressure in the metal pipe 73 into the pressure receiving portion 82. A part of the metal housing 81 is in contact with the metal pipe 73, and the metal housing 81 and the metal pipe 73 are electrically connected. A portion of the pressure sensor 68 protrudes into the metal pipe 73. The introduction passage 83 communicates the pressure receiving portion 82 with the inside of the metal pipe 73. The pressure receiving portion 82 is a diaphragm that deforms in accordance with the pressure of the introduction passage 83. The pressure sensor 68 includes four gauges (piezoresistive elements) whose resistance value changes with the deformation of the pressure receiving portion 82. The four gauges are connected in a full bridge, and a change in resistance of the gauges due to the deformation of the pressure receiving portion 82 outputs a detection result (electrical signal = voltage) according to the pressure.

  The fuel cell stack 20 includes a plurality of first bolts 75 for fixing the induction member 71 to the fuel cell stack 20 and a plurality of second bolts 76 for fixing the metal pipe 73 to the induction member 71. The first bolt 75 and the second bolt 76 are both made of metal. The first bolt 75 passes through the guiding member 71 and is fastened to the metal plate 24. The second bolt 76 is inserted into the flange 74 of the metal pipe 73 and fastened to the guide member 71. The second bolt 76 is provided so as not to reach the metal plate 24. Therefore, the second bolt 76 and the metal plate 24 are not in contact with each other.

  The fuel cell system 10 includes a jumper wire 90 for electrically connecting the first bolt 75 and the second bolt 76. The jumper wire 90 includes terminals 91 and 92 provided at both ends, and a resistor 93. Each of the terminals 91 and 92 is annular or C-shaped, and bolts 75 and 76 can be inserted therethrough.

  One first bolt 75 is inserted through the terminal 91 of the jumper wire 90. The terminal 91 of the jumper wire 90 is tightened together with the induction member 71 by one first bolt 75 of the plurality of first bolts 75. One second bolt 76 is inserted through the terminal 92 of the jumper wire 90. The terminal 92 of the jumper wire 90 is fastened together with the metal pipe 73 by one second bolt 76 among the plurality of second bolts 76. The first bolt 75 and the second bolt 76 are electrically connected by the jumper wire 90. Here, the metal casing 81 of the pressure sensor 68 and the metal pipe 73 are electrically connected, and the metal pipe 73 and the second bolt 76 are electrically connected. Furthermore, the first bolt 75 and the metal plate 24 are electrically connected. Therefore, the metal casing 81 of the pressure sensor 68, the metal piping 73, the first bolt 75, the jumper wire 90, the second bolt 76, and the metal plate 24 are electrically connected. Since the metal plate 24 is grounded, the metal pipe 73 electrically connected to the metal plate 24 is also electrically connected (grounded) to the ground. In addition, since the metal pipe 73 and the metal casing 81 of the pressure sensor 68 are electrically connected, the metal pipe 73 is electrically connected to the ground, so that the pressure sensor 68 is also electrically connected to the earth. It can be said that it is connected.

Next, the operation of the fuel cell system 10 of the present embodiment will be described.
When the fuel cell stack 20 generates power, cathode exhaust gas is generated. When the cathode exhaust gas flows through the metal pipe 73, the metal pipe 73 is charged. It is presumed that this is caused by the fact that the charged water contained in the cathode exhaust gas adheres to the metal pipe 73. Since insulating members are provided on both sides of the metal pipe 73 in the flow direction of the cathode exhaust gas, if the jumper wire 90 is not provided, the metal pipe 73 can not release the charge, and the metal pipe 73 is not provided. 73 is maintained in a charged state. Since the metal pipe 73 and the metal casing 81 of the pressure sensor 68 are electrically connected, if the metal pipe 73 is maintained in a charged state, the resistance value of the gauge of the pressure sensor 68 fluctuates due to the influence of the charge. Do. That is, the resistance value of the gauge fluctuates due to a factor other than the deformation of the pressure receiving portion 82, which causes an error to be included in the detection result of the pressure sensor 68.

  On the other hand, in the present embodiment, since the metal pipe 73 is electrically connected to the ground, when the metal pipe 73 is charged, a potential difference occurs between the metal pipe 73 and the frame F, and the metal pipe 73 and the frame F A current flows between it and (earth). As a result, the charged electric charge is released to the metal pipe 73.

  Moreover, when the jumper wire 90 is equipped with the resistor 93, when the total minus terminal 23 and the metal piping 73 conduct | electrically_connect, it can suppress that the fuel cell 21 and an earth | ground short-circuit. It can be said that the resistor 93 is provided to prevent a short circuit between the fuel cell 21 and the ground. The resistance value of the resistor 93 can be set so that a short circuit between the fuel cell 21 and the ground can be prevented, and a charge can be released when the metal pipe 73 is charged.

Therefore, according to the said embodiment, the following effects can be acquired.
(1) The metal pipe 73 is electrically connected to the ground. When the metal pipe 73 is charged, the electric charge held by the metal pipe 73 is released, which prevents the metal pipe 73 from being maintained in a charged state. Therefore, it is possible to suppress the occurrence of an error (systematic error) in the detection result of the pressure sensor 68 due to the influence of the charging of the metal pipe 73.

  It is also conceivable to suppress the error from being included in the detection result of the pressure sensor 68 by using a pipe made of an insulating material instead of the metal pipe 73. However, in the piping to which the air pressure regulating valve 65 is fixed, strength is required to fix the air pressure regulating valve 65. If the metal pipe 73 is a pipe made of an insulating material, the strength may be insufficient. Therefore, the pipe to which the air pressure regulating valve 65 is fixed is preferably the metal pipe 73. By electrically connecting the metal pipe 73 to the ground, it is possible to suppress an error in the detection result of the pressure sensor 68 while securing the strength necessary for the pipe.

  (2) The metal pipe 73 is electrically connected to the ground by being electrically connected to the metal plate 24. As described above, by electrically connecting the metal plate 24 and the metal pipe 73, the metal pipe 73 can be electrically connected to the ground by using a member that is grounded.

  (3) The metal piping 73 is electrically connected to the ground by connecting the first bolt 75 and the second bolt 76 with the jumper wire 90. The first bolt 75 is electrically connected to the metal pipe 73, and the second bolt 76 is electrically connected to the metal plate 24. Therefore, by connecting the first bolt 75 and the second bolt 76 with the jumper wire 90, the metal pipe 73 can be easily electrically connected to the ground.

  (4) The terminals 91 and 92 of the jumper wire 90 are shaped such that the bolts 75 and 76 can be inserted. The first bolt 75 through which the terminals 91 and 92 are inserted is fastened to the metal plate 24 and the second bolt 76 through which the terminals 91 and 92 are inserted is fastened to the induction member 71 to perform electrical connection by the jumper wire 90 Can. Therefore, the jumper wire 90 can be easily connected.

  (5) The jumper wire 90 includes a resistor 93. When the total minus terminal 23 and the metal pipe 73 conduct, short circuit between the fuel cell 21 and the ground can be suppressed.

The embodiment may be modified as follows.
The jumper wire 90 may not have the resistor 93. In this case, it is preferable to prevent conduction between the metal pipe 73 and the total minus terminal 23. For example, a member may be provided to prevent conduction between the metal pipe 73 and the total minus terminal 23, or the positional relationship between the metal pipe 73 and the total minus terminal 23 may be adjusted to suppress conduction between the two. You may

  The jumper wire 90 may not have the terminals 91 and 92. In this case, the jumper wire 90 may be joined to the first bolt 75 and the second bolt 76. In addition, the jumper wire 90 may be wound around the axis of the first bolt 75 and the axis of the second bolt 76. In any case, since the metal pipe 73 can be electrically connected to the ground by fastening the first bolt 75 and the second bolt 76, the metal pipe 73 can be easily electrically connected to the ground. it can.

  The metal pipe 73 and the induction member 71 may be fastened together by a metal bolt. In this case, the bolt passes through the flange 74 of the metal pipe 73 and the induction member 71 and is fastened to the metal plate 24. The metal pipe 73 and the metal plate 24 are electrically connected by bolts, whereby the metal pipe 73 is electrically connected to the ground. That is, the metal pipe 73 and the metal plate 24 can be electrically connected without using the jumper wire 90. In this case, the first bolt 75 and the second bolt 76 may or may not be provided.

  The metal pipe 73 may be electrically connected to anything other than the metal plate 24 as long as it is a member grounded. Further, the metal pipe 73 and the frame F may be electrically connected by providing a conductor for connecting the metal pipe 73 and the frame F (earth). Even in these cases, the metal pipe 73 is electrically connected to the ground.

  In the embodiment, the metal pipe 73 through which the cathode exhaust gas flows as a gas is electrically connected to the ground, but the invention is not limited thereto. In the fuel cell stack 20, in the metal pipe and the flow direction of the gas flowing through the metal pipe, in the flow path in which the insulating members are provided on both sides of the metal pipe, the same problem as the embodiment may occur. For example, when the second hydrogen discharge flow path 48 provided with the anode pressure sensor 46 as a pressure sensor is composed of metal piping and insulating members provided on both sides of the metal piping in the flowing direction of the anode exhaust gas The charging of the metal pipe may cause an error in the detection result of the anode pressure sensor 46. In this case, by electrically connecting the metal pipe that constitutes the second hydrogen discharge flow path 48 to the ground, it is possible to suppress the occurrence of an error in the detection result of the anode pressure sensor 46.

  Similarly, when each air supply flow path 63, 64 and each hydrogen supply flow path 42, 43 are constituted by metal piping and an insulating member, and a pressure sensor is installed in the metal piping, these flow paths The metal piping which comprises may be electrically connected to earth. Even in the air supply flow channels 63 and 64 and the hydrogen supply flow channels 42 and 43, the metal pipe 73 can be charged due to the influence of the use environment of the fuel cell system 10 or the like.

  As described above, it is a metal pipe through which the gas supplied to the fuel cell stack 20 or the gas discharged from the fuel cell stack 20 flows, and if it is a metal pipe on which a pressure sensor is installed, it is electrically grounded By connecting them in the same manner, the same effect as that of the embodiment can be obtained.

As the pressure sensor 68, any pressure sensor 68 may be used as long as it outputs pressure as an electrical signal, such as a capacitance type.
The fuel cell stack 20 may be one mounted on a portable device or one used as a stationary power source. In this case, the ground (reference potential) is determined according to the mounting object of the fuel cell stack 20 or the like.

  In the flow direction of the cathode exhaust gas, the insulating members provided on both sides of the metal pipe 73 may be one that changes the direction of the flow path like the induction member 71 or may be other than the air pressure adjustment valve 65. For example, a joint made of an insulating material or a pipe (such as a rubber hose) made of an insulating material may be used. The first insulating member and the second insulating member may be members made of an insulating material, and may be, for example, members made of rubber.

  The metal casing 81 of the pressure sensor 68 may be connected to the ground by a conductor such as a wire. Since the metal piping 73 and the metal casing 81 are electrically connected, the metal piping 73 is also electrically connected to the ground.

  DESCRIPTION OF SYMBOLS 10 Fuel cell system 20 Fuel cell stack 21 Fuel battery cell 24, 26 Metal plate 65 Air pressure regulation valve (2nd insulation member) 68 Pressure sensor 71 Induction member 1st insulation Parts), 73 ... metal piping, 75 ... 1st bolt, 76 ... 2nd bolt, 90 ... jumper wire, 93 ... resistor.

Claims (5)

A fuel cell stack,
A metal pipe through which a gas supplied to the fuel cell stack or a gas discharged from the fuel cell stack flows;
A first insulating member disposed upstream of the metal pipe in a flow direction of gas flowing through the metal pipe;
A second insulating member disposed downstream of the metal pipe in the flow direction of the gas flowing through the metal pipe;
A pressure sensor installed in the metal pipe and detecting a pressure of a gas flowing through the metal pipe;
The fuel cell system in which the metal pipe is electrically connected to the ground. The fuel cell stack is
With multiple fuel cells,
And two metal plates sandwiching and holding the plurality of fuel cells.
One of the two metal plates is grounded,
The fuel cell system according to claim 1, wherein the metal pipe and the grounded metal plate are electrically connected. The metal pipe has a flange,
A metal first bolt inserted through the first insulating member and fastened to the grounded metal plate;
A metal second bolt inserted through the flange and fastened to the first insulating member;
The fuel cell system according to claim 2, further comprising: a jumper wire connecting the first bolt and the second bolt.   The fuel cell system according to claim 3, wherein the jumper wire comprises a resistor.   The fuel cell system according to any one of claims 1 to 4, wherein the metal pipe is a gas through which a gas containing air discharged from the fuel cell stack flows.