Fuel cell system

Abstract

To provide a fuel cell system equipped with a filter capable of supplying air from which sea water particles present in the air have been removed, while suppressing pressure loss.SOLUTION: A fuel cell system 1 includes: a fuel cell 2 for receiving gas supply and generating power; an oxidant gas supply pipe 10 for supplying gas to the fuel cell 2; and a filter 15 provided in the oxidant gas supply pipe 10, the filter removing impurities in the gas. The filter 15 is formed of a metal porous body and is heated to at least a predetermined temperature.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fuel cell system provided with a filter provided in a gas flow path communicating with a fuel cell for removing impurities in the gas.

Background Art

[0002] In a fuel cell system, hydrogen gas is supplied as a fuel gas to the anode electrode side of a fuel cell configured by stacking a plurality of power generation cells formed by sandwiching between an anode electrode and a cathode electrode, and air is supplied as an oxidizing gas to the cathode electrode side, thereby generating power. And it is common to use oxygen in the atmosphere as the oxidizing gas supplied to the cathode electrode, and the air taken in from the atmosphere is supplied to the cathode electrode of the fuel cell. However, since the atmosphere contains dust, it is necessary to remove the dust in the air before supplying it to the fuel cell. Conventionally, the dust has been removed by a filter impregnated with a liquid (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when using a fuel cell system in a coastal area, since seawater particles are present in the air contained in the atmosphere, it is necessary to remove the seawater particles. However, since the fuel cell system described in Patent Document 1 removes dust by a filter impregnated with a liquid, even if the seawater particles can be removed, there is a possibility that the pressure loss will be large and the power generation capacity will decrease. On the other hand, in order to reduce the pressure loss, if the amount of the impregnated liquid is reduced, there is a problem that the seawater particles present in the air contained in the atmosphere cannot be sufficiently removed.

[0005] Therefore, an object of the present invention is to provide a fuel cell system including a filter capable of supplying air from which seawater particles present in the air have been removed while suppressing pressure loss.

Means for Solving the Problems

[0006] One aspect of the present invention is a fuel cell system including a fuel cell that generates electricity by receiving a gas supply, a gas supply passage that communicates with the fuel cell and supplies the gas to the fuel cell, and a filter provided in the gas supply passage to remove impurities in the gas, wherein the filter is composed of a metal porous body and is heated to a predetermined temperature or higher.

Effects of the Invention

[0007] According to the present invention, it is possible to provide a fuel cell system including a filter capable of supplying air from which seawater particles present in the air have been removed while suppressing pressure loss.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] Hereinafter, with reference to FIG. 1, the fuel cell system according to the present embodiment will be described. FIG. 1 is a configuration diagram showing the fuel cell system according to the present embodiment. Hereinafter, the fuel cell system 1 according to the present embodiment is applied to an in-vehicle power generation system of a fuel cell vehicle. However, the fuel cell system 1 is not limited to the in-vehicle power generation system of a fuel cell vehicle, and can also be applied to mobile bodies such as ships, airplanes, and trains, or to stationary power generation systems used as power generation facilities for buildings (houses, buildings, etc.).

[0010] The fuel cell system 1 includes a fuel cell 2 configured by stacking a plurality of cells formed by sandwiching a solid polymer electrolyte membrane between an anode electrode and a cathode electrode. The fuel cell 2 generates electricity when a fuel gas is supplied to the anode electrode and an oxidant gas is supplied to the cathode electrode. In the present embodiment, a case where hydrogen is used as the fuel gas and air is used as the oxidant gas will be described.

[0011] The fuel cell system 1 includes a hydrogen system (not shown) for supplying hydrogen to the fuel cell 2, an air system 3 for supplying air to the fuel cell 2, and a cooling system 4 for cooling the fuel cell 2. In the fuel cell system 1 according to the present embodiment, since a known configuration is used for the hydrogen system, a detailed description thereof will be omitted. In the hydrogen system, hydrogen is stored in a fuel tank (not shown), and is supplied from this fuel tank to the fuel cell 2 via a hydrogen supply flow path (not shown).

[0012] The cooling system 4 has a closed-loop cooling water passage 7 through which cooling water that cools the heat generated when the fuel cell 2 generates electricity circulates. A circulation pump (not shown) for circulating the cooling water is provided in this cooling water passage 7. By operating this circulation pump, the cooling water in the cooling water passage 7 circulates. A cooling water tank 8 is provided in the cooling water passage 7. The cooling water tank 8 functions as a buffer, and the cooling water that has cooled the fuel cell 2 and has had its temperature increased is stored in the cooling water tank 8 via the cooling water passage 7. Further, the cooling system 4 has a radiator (not shown) connected in parallel to the cooling water tank 8. A fan for blowing air to the radiator is provided in this radiator. When the cooling water has risen above a predetermined temperature due to cooling of the fuel cell 2, the cooling water flows through the radiator and is cooled by the radiator. The cooled cooling water is supplied to the fuel cell 2. The temperature of the cooling water that has cooled the fuel cell 2 and has returned to the cooling water tank 8 is approximately 80°C.

[0013] In the air system 3, air is used as the oxidant gas supplied to the cathode electrode, and the air used as the oxidant gas is atmospheric air. The air system 3 includes an oxidant gas supply pipe 10 used to supply air from the atmosphere to the fuel cell 2, and an oxidant gas discharge pipe 11 used to discharge to the outside the air, which is the oxidant gas used in the power generation reaction from the fuel cell 2. Further, the air system 3 has a compressor (not shown). The compressor takes in and pressurizes the air in the atmosphere, and the air taken in and pressurized by the compressor is supplied to the fuel cell 2 through the oxidant gas supply pipe 10. The air used and discharged at the cathode electrode is discharged to the outside through the oxidant gas discharge pipe 11. The oxidant gas supply pipe 10 is the gas supply passage in the present invention.

[0014] The fuel cell system 1 in the present embodiment takes in air from the atmosphere and supplies it to the cathode electrode of the fuel cell 2. However, since the atmosphere contains dust, it is necessary to remove the dust in the air before supplying it to the fuel cell 2. Therefore, the air system 3 is provided with a filter unit 14 having a filter 15. The filter unit 14 is provided at the intake port 12 of the oxidant gas supply pipe 10. In FIG. 1, for ease of understanding, the filter unit 14 is arranged at a location away from the intake port 12 of the oxidant gas supply pipe 10. However, in the present embodiment, the filter unit 14 is provided at the intake port 12 of the oxidant gas supply pipe 10. Incidentally, if the filter unit 14 is provided in the oxidant gas supply pipe 10 and the air supplied to the cathode electrode passes through the filter 15, the filter unit 14 may be provided at any of the outlet of the oxidant gas supply pipe 10, which is between the fuel cell 2 and the oxidant gas supply pipe 10, in the middle of the oxidant gas supply pipe 10, or at the intake port 12 of the oxidant gas supply pipe 10.

[0015] The filter unit 14 has a filter 15 and a fixing frame 16 for fixing the filter 15. The filter 15 is formed in a substantially rectangular shape, and the four sides of the substantially rectangular filter 15 are fixed by the fixing frame 16. As shown in FIG. 2, the filter 15 is composed of a metal porous body having a three-dimensional mesh structure. The metal porous body constituting the filter 15 is formed of Ni. In this embodiment, the metal porous body constituting the filter 15 is formed of Ni, but it may be formed of any one of NiCr, NiSn, Al, Ti, and brass. The fixing frame 16 is made of metal, specifically, made of Al. The sizes of the length (height in the air flow direction), width (width orthogonal to the air flow direction), and thickness (thickness in the air flow direction) of the filter 15 are 200 mm in length, 200 mm in width, and 30 mm to 100 mm in thickness.

[0016] The fuel cell system 1 according to this embodiment is applied to an in-vehicle power generation system of a fuel cell vehicle. Therefore, a fuel cell vehicle to which the fuel cell system 1 according to this embodiment is applied may naturally be used in a coastal area near the coast. When the fuel cell system 1 is used in a coastal area, since seawater particles are present in the air contained in the atmosphere, it is necessary to remove the seawater particles. Therefore, the fuel cell system 1 according to this embodiment has the following characteristics.

[0017] The fuel cell system 1 has a heat transfer member 17 that is connected to the cooling water stored in the cooling water tank 8 and the fixing frame 16 of the filter unit 14, and transfers the heat of the cooling water to the filter 15 to heat the filter 15. The heat transfer member 17 is formed of an Al member. Note that although the heat transfer member 17 is formed of an Al member, it may be formed of other materials as long as the material has high thermal conductivity. The same applies to the fixing frame 16. The fixing frame 16 may be formed of other materials as long as the material has high thermal conductivity. Since the fixing frame 16 and the heat transfer member 17 are made of Al and are formed of a material with high thermal conductivity, the heat of the cooling water (approximately 80°C) is transferred to the filter 15 to heat the filter 15. That is, the filter 15 is heated to a predetermined temperature or higher by being heat-transferred through the cooling water that cools the heat generated by the power generation of the fuel cell 2. Since the filter 15 is heated to a predetermined temperature or higher through the cooling water that cools the heat generated by the power generation of the fuel cell 2, even if there are seawater particles in the air contained in the atmosphere before passing through the filter 15, the seawater particles are removed by the filter 15 of the present embodiment.

[0018] With reference to FIG. 1, the operation of the filter 15 of the present embodiment will be described. In FIG. 1, the shape indicated by the cloud shape represents the air A, and the circles existing in the air A indicated by the cloud shape represent the seawater particles S. When the fuel cell system 1 is used in a coastal area, there are many seawater particles S in the air A contained in the atmosphere before passing through the filter 15. The filter 15 is heated to a predetermined temperature (80°C in the present embodiment) or higher through the cooling water that cools the heat generated by the power generation of the fuel cell 2. Therefore, the seawater particles contained in the air passing through the filter 15 come into contact with the metal porous body constituting the heated filter 15, and the moisture evaporates, changes to solid NaCl, and adheres to the metal porous body. As a result, air without seawater particles is supplied to the fuel cell 2.

[0019] The fuel cell system 1 in the present embodiment has a filter 15 that is heated to a predetermined temperature or higher through cooling water that cools the heat generated by the power generation of the fuel cell 2, and seawater particles S in the air contained in the atmosphere are removed by the filter 15. However, since NaCl removed from the air contained in the atmosphere adheres to the filter 15, it is necessary to wash away the NaCl adhering to the filter 15. Therefore, the fuel cell system 1 according to the present embodiment has the following features.

[0020] The fuel cell system 1 includes a gas-liquid separator 25 provided in the oxidant gas discharge pipe 11, a buffer tank 26 that stores the generated water separated by the gas-liquid separator 25, and a drain nozzle 30 that drains the generated water stored in the buffer tank 26 to the filter 15. A plurality of nozzle holes 31 for draining the generated water are formed in the drain nozzle 30. A generated water discharge pipe 27 is connected between the gas-liquid separator 25 and the buffer tank 26. The air, which is the oxidant gas used in the power generation reaction from the fuel cell 2, contains the generated water generated by the power generation. The gas-liquid separator 25 separates the oxidant gas used in the power generation reaction and containing the generated water into the generated water and the air not containing the generated water. The air not containing the generated water separated by the gas-liquid separator 25 is discharged to the atmosphere through the oxidant gas discharge pipe 11. The generated water separated by the gas-liquid separator 25 is discharged to the buffer tank 26 through the generated water discharge pipe 27. A generated water supply pipe 28 is connected between the buffer tank 26 and the drain nozzle 30. An electromagnetic valve 29 is provided in the generated water supply pipe 28, and the opening and closing of the electromagnetic valve 29 cause the generated water to be drained or not drained from the drain nozzle 30. The drain nozzle 30 and the buffer tank 26 are arranged above the filter 15 in the height direction. More specifically, the longitudinal length of the drain nozzle 30 is substantially the same as the horizontal length of the filter 15 so that the drain nozzle 30 and the buffer tank 26 are arranged above the filter unit 14 having the filter 15 and the fixing frame 16 in the height direction so that the generated water can be drained over the entire area of the filter 15. Since the drain nozzle 30 and the buffer tank 26 are arranged above the filter 15 in the height direction, the generated water can be drained from the drain nozzle 30 to the filter 15 without a pump that requires power, and by draining the generated water to the filter 15, the NaCl adhering to the filter 15 can be washed away. Incidentally, the generated water supply pipe 28 is the generated water supply passage in the present invention.

[0021] The fuel cell system 1 has a control device 35 that controls the solenoid valve 29. The control device 35 is also connected to an ECU 36 that controls the fuel cell vehicle and can receive a signal for stopping support of the fuel cell 2 from the ECU 36. The control device 35 performs the following control.

[0022] After the control device 35 receives a signal for stopping instruction of the fuel cell 2 from the ECU 36 and a predetermined time has elapsed, it opens the solenoid valve 29. In the present embodiment, the predetermined time is set to 5 seconds. As a result, the generated water stored in the buffer tank 26 is drained from the drain nozzle 30 to the filter 15, and the NaCl adhering to the filter 15 can be washed away. Also, by setting the predetermined time to 5 seconds, immediately after the stop instruction of the fuel cell 2, there is still a flow of air from the atmosphere into the fuel cell 2, and if the generated water is drained by the drain nozzle 30 at this time, it is possible to suppress the flow of droplets containing NaCl into the fuel cell 2. When the control device 35 does not receive a signal for stopping instruction of the fuel cell 2 from the ECU 36, it closes the solenoid valve 29.

[0023] The fuel cell system 1 according to the present embodiment includes a fuel cell 2 that generates electricity by receiving a gas supply, an oxidant gas supply pipe 10 that communicates with the fuel cell 2 and supplies a gas to the fuel cell 2, and a filter 15 provided in the oxidant gas supply pipe 10 that removes impurities in the gas. The filter 15 is composed of a metal porous body and is heated to a predetermined temperature or higher. Therefore, it is possible to supply the fuel cell 2 with air that can sufficiently remove seawater particles present in the air contained in the atmosphere without significantly increasing the pressure loss. As a result, a decrease in power generation performance can be suppressed, and as a result, it is possible to contribute to extending the life of the fuel cell 2. In the present embodiment, in order to heat the filter 15 to a predetermined temperature or higher, the heat generated by the power generation of the fuel cell 2 is used, but it is not necessarily limited to this. For example, other heat-generating devices such as a compressor for vehicle air conditioning, a drive motor for driving the wheels of the fuel cell vehicle, and an inverter for controlling the drive motor for driving the wheels of the fuel cell vehicle may be used to heat the filter 15.

[0024] In the fuel cell system 1 according to this embodiment, the filter 15 is heated to a predetermined temperature or higher by the heat generated when the fuel cell 2 generates power. Therefore, without providing a dedicated heater, it is possible to supply to the fuel cell 2 air that can sufficiently remove seawater particles present in the air contained in the atmosphere without significantly increasing the pressure loss. As a result, a decrease in power generation performance can be suppressed, and thus, it is possible to contribute to extending the service life of the fuel cell 2. In this embodiment, the filter 15 was heated to a predetermined temperature or higher through cooling water that cools the heat generated when the fuel cell 2 generates power, but it is not necessarily limited to this. The filter 15 may be heated to a predetermined temperature or higher using another part of the fuel cell 2 that becomes hot, instead of the cooling water that cools the heat generated when the fuel cell 2 generates power.

[0025] In the fuel cell system 1 according to this embodiment, the filter 15 is heated to a predetermined temperature or higher through cooling water that cools the heat generated when the fuel cell 2 generates power. Therefore, without providing a dedicated heater and with less risk of electric leakage, it is possible to supply to the fuel cell 2 air that can sufficiently remove seawater particles present in the air contained in the atmosphere without significantly increasing the pressure loss. As a result, a decrease in power generation performance can be suppressed, and thus, it is possible to contribute to extending the service life of the fuel cell 2. Also, heating the filter 15 with the cooling water means that the cooling water will be cooled by the filter 15, so the operation of the fan that blows air through the radiator can be reduced, or the cooling water can be cooled without using the radiator.

[0026] The fuel cell system 1 according to this embodiment has a buffer tank 26 that stores the generated water produced by the power generation of the fuel cell 2, and a drain nozzle that discharges the generated water stored in the buffer tank 26 to the filter 15. The buffer tank 26 and the drain nozzle 30 are arranged above the filter 15, and the generated water is discharged from the drain nozzle 30 to the filter 15. Therefore, the replacement work of the filter 15 becomes unnecessary, and a fatal output drop due to forgetting to replace the filter 15 can also be suppressed. In addition, since the generated water that flushes away the NaCl attached to the filter 15 is discharged from the fuel cell 2, replenishment is not required. In this embodiment, a dedicated drain nozzle 30 is provided to discharge the generated water to the filter 15, but it is not necessarily required to provide a dedicated drain nozzle 30. For example, a generated water supply pipe 28 may be connected to a portion (upper side fixing frame) of the fixing frame 16 that is located above the filter 15, nozzle holes may be formed in the upper side fixing frame, and the generated water may be discharged from the upper side fixing frame to the filter 15.

[0027] As described above, the embodiments and their modifications of the present invention have been described. However, the present invention is not limited to the above-described embodiments and modifications, and further modifications and changes are possible based on the technical idea of the present invention.

[0028] For example, in FIG. 1, in this embodiment, the oxidant gas discharge pipe 10 is connected to the upper side of the fuel cell, and the oxidant gas supply pipe 11 is connected to the lower side of the fuel cell. However, it is not necessarily limited to this. As long as the drain nozzle 30 and the buffer tank 26 are arranged above the filter 15 in the height direction, the oxidant gas discharge pipe 10 may be connected to the lower side of the fuel cell, and the oxidant gas supply pipe 11 may be connected to the upper side of the fuel cell.

Explanation of Reference Numerals

[0029] 1... Fuel cell system 2... Fuel cell 3... Air system 4... Cooling system 7... Cooling water channel 8... Cooling water tank 10…Oxidizing agent gas supply pipe 11…Oxidizing agent gas discharge pipe 12…Intake port 14…Filter section 15…Filter 16…Fixing frame 17…Heat transfer member 25…Gas-liquid separator 26…Buffer tank 27…Product water discharge pipe 28…Product water supply pipe 29…Solenoid valve 30…Drain nozzle 31…Nozzle hole 35…Control device 36…ECU A…Air S…Seawater particles

Claims

1. A fuel cell system comprising a fuel cell that generates electricity upon receiving a gas supply, a gas supply passage that supplies the gas to the fuel cell, and a filter provided in the gas supply passage to remove impurities in the gas, wherein the filter is composed of a metal porous body and is heated to a predetermined temperature or higher, characterized fuel cell system.

2. The fuel cell system according to claim 1, wherein the filter is heated to the predetermined temperature or higher by heat generated by the fuel cell during power generation.

3. The fuel cell system according to claim 2, wherein heat generated by the fuel cell during power generation is transferred to the filter through cooling water that cools the fuel cell, so that the filter is heated to the predetermined temperature or higher.

4. A buffer tank for storing generated water generated by the fuel cell during power generation, and a drain nozzle for draining the generated water stored in the buffer tank to the filter, wherein the buffer tank and the drain nozzle are disposed above the filter, The fuel cell system according to any one of claims 1 to 3, characterized in that the generated water is drained from the drain nozzle to the filter.

5. A generated water supply passage connecting the buffer tank and the drain nozzle, a solenoid valve provided in the generated water supply passage, and a control device capable of receiving a signal for instructing the stop of the fuel cell and controlling the solenoid valve, The fuel cell system according to claim 4, wherein the control device opens the solenoid valve to drain the generated water to the filter when receiving a signal for instructing the stop of the fuel cell, and closes the solenoid valve when not receiving a signal for instructing the stop of the fuel cell.

6. The fuel cell system according to any one of claims 1 to 3, wherein the metal porous body is formed of any one of Ni, NiCr, NiSn, Al, Ti, and brass.

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