Fuel cell system

Abstract

In the fuel supply passage upstream of the fuel adjustment device, ensure sufficient strength in the piping, and in the fuel supply passage downstream of the fuel adjustment device, ensure sufficient flexibility in the piping. [Solution] The fuel cell system 1 includes an FC stack 11 that generates electricity by receiving hydrogen and air. It includes a hydrogen supply passage 31 for supplying hydrogen to the FC stack 11, and an injector 54 provided in the hydrogen supply passage 31 for adjusting the amount of hydrogen supplied to the FC stack 11. The piping upstream of the injector 54 in the hydrogen supply passage 31 is made of metal only, and at least a portion of the piping downstream of the injector 54 is made of resin or rubber.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a fuel cell system equipped with a fuel cell that generates electricity by receiving supplies of fuel and an oxidant.

Background Art

[0002] Conventionally, as this type of technology, for example, a "fuel cell system" described in Patent Document 1 below is known. This system includes a fuel cell, a hydrogen supply passage (fuel supply passage) that supplies hydrogen (fuel) to the fuel cell, and an injector (fuel adjustment device) disposed in the fuel supply passage that adjusts the amount of fuel supplied to the fuel cell. Here, a part of the piping upstream of the fuel adjustment device in the fuel supply passage includes a resin pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the fuel cell system described in Patent Document 1, when an abnormally high fuel pressure acts on the fuel supply passage upstream of the fuel adjustment device, since a part of the piping is made of resin, strength becomes an issue. To avoid this abnormally high pressure state, it is necessary to install a large relief valve in the piping. Also, in order to ensure the strength of the piping, it is conceivable to make all of the piping in the fuel supply passage out of metal. However, metal piping lacks flexibility, has a small margin for assembly, and also becomes costly.

[0005] This disclosed technology has been made in view of the above circumstances, and its purpose is to provide a fuel cell system that ensures strength in the piping in the fuel supply passage upstream of the fuel adjustment device, and ensures flexibility in the piping in the fuel supply passage downstream of the fuel adjustment device. [Means for solving the problem]

[0006] To achieve the above objective, the technology described in claim 1 is a fuel cell system comprising a fuel cell that generates electricity by receiving a supply of fuel and an oxidizer, wherein the system comprises a fuel supply passage for supplying fuel to the fuel cell, and a fuel adjustment device provided in the fuel supply passage for adjusting the amount of fuel supplied to the fuel cell, wherein the piping upstream of the fuel adjustment device in the fuel supply passage is made of metal only, and at least a portion of the piping downstream of the fuel adjustment device is made of resin or rubber.

[0007] According to the above technology configuration, since the piping upstream of the fuel adjustment device in the fuel supply passage is made of metal only, the rigidity of the passage is increased in that section of the fuel supply passage. Furthermore, since at least a portion of the piping downstream of the fuel adjustment device is made of resin or rubber, elasticity or flexibility is obtained in at least a portion of the fuel supply passage in that section.

[0008] To achieve the above objective, the technology described in claim 2 is intended to be the same as the technology described in claim 1, but with all of the piping downstream of the fuel adjustment device in the fuel supply passage made of resin or rubber.

[0009] According to the configuration of the above technology, in addition to the effects of the technology described in claim 1, since all of the piping downstream of the fuel adjustment device in the fuel supply passage is made of resin or rubber, elasticity or flexibility is obtained in the entire fuel supply passage in that section. [Effects of the Invention]

[0010] According to the technology described in claim 1, strength can be ensured in the piping in the fuel supply passage upstream of the fuel supply device, and flexibility can be ensured in the piping in the fuel supply passage downstream of the fuel supply device.

[0011] According to the technology described in claim 2, in addition to the effects of the technology described in claim 1, flexibility can be ensured throughout the entire fuel supply passage downstream of the fuel adjustment device. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic diagram illustrating a fuel cell system according to one embodiment. [Figure 2] An enlarged view showing a portion of the hydrogen system in Figure 1, relating to one embodiment. [Modes for carrying out the invention]

[0013] Below, one embodiment of a fuel cell system implemented in an electric vehicle will be described in detail with reference to the drawings.

[0014] [Regarding the configuration of the fuel cell system] Figure 1 shows a schematic configuration diagram of the fuel cell system 1 of this embodiment. As shown in Figure 1, this fuel cell system 1 comprises an FC stack 11, a hydrogen system 21, and an air system 22.

[0015] Hydrogen system 21 is a circuit for supplying fuel to the FC stack 11. Air system 22 is a circuit for supplying an oxidizer to the FC stack 11. In this embodiment, the fuel is hydrogen (hydrogen gas) and the oxidizer is air. The FC stack 11 generates electricity by receiving hydrogen from the hydrogen system 21 and air from the air system 22, and is an example of a "fuel cell" in this disclosed technology. The electricity generated by the FC stack 11 is supplied to a battery and an inverter (neither of which are shown).

[0016] The hydrogen system 21 is installed on the anode side of the FC stack 11. This hydrogen system 21 includes a hydrogen supply passage 31, an exhaust drainage passage 32, a filling passage 33, and a circulation passage 34.

[0017] The hydrogen supply passage 31 is a passage for supplying hydrogen from the hydrogen tank 41, where hydrogen is stored, to the FC stack 11. The exhaust and drainage passage 32 is a passage for discharging hydrogen (i.e., hydrogen off-gas) and wastewater emitted from the FC stack 11. The hydrogen supply passage 31 corresponds to an example of a "fuel supply passage" in this disclosed technology.

[0018] Furthermore, the hydrogen system 21 includes, in order from the hydrogen tank 41 side, a hydrogen valve 51, a hydrogen pressure reducing valve 52, a relief valve 53, and an injector 54 in the hydrogen supply passage 31.

[0019] The filling passage 33 is a passage for filling the hydrogen tank 41 with hydrogen from the filling port 42. The circulation passage 34 is a passage connecting the exhaust drainage passage 32 (including the gas-liquid separator 56) and the injector 54, and is a passage for circulating hydrogen off-gas to the injector 54. The circulation passage 34 is equipped with a hydrogen pump 55 for pressurizing and supplying hydrogen off-gas to the injector 54.

[0020] The hydrogen valve 51 is a valve that switches between supplying and shutting off hydrogen from the hydrogen tank 41 to the hydrogen supply passage 31. This valve 51 is composed of multiple devices, for example, a solenoid valve. The hydrogen pressure reducing valve 52 is a pressure regulating valve for reducing the hydrogen pressure. The relief valve 53 is a valve that releases a portion of the pressure to the outside when an abnormally high hydrogen gas pressure acts on the hydrogen supply passage 31.

[0021] The injector 54 is a device that injects hydrogen led from the hydrogen tank 41 to the downstream side. The injector 54 is constituted by, for example, a solenoid valve. The injector 54 is configured to adjust the discharge pressure (hydrogen pressure) of hydrogen, for example, by adjusting the opening degree of the injection port by the movement of a needle valve. Further, the injector 54 takes in the hydrogen off-gas flowing through the circulation passage 34, mixes the hydrogen off-gas with hydrogen, and discharges it to the downstream side. In this embodiment, the connection of the piping to the injector 54 is performed by screwing the male thread of the piping into the female thread of the injector 54. The injector ursub>54 corresponds to an example of the "fuel adjustment device" of this disclosed technology.

[0022] The hydrogen system 21 includes a gas-liquid separator 56 and an exhaust drain valve 57 in the exhaust drain passage 32. The gas-liquid separator 56 is an electric device that separates moisture in the hydrogen off-gas. The exhaust drain valve 57 is a valve that switches between discharging and blocking the hydrogen off-gas and moisture from the gas-liquid separator 56. This valve 57 is constituted by, for example, a solenoid valve.

[0023] Here, the assumed pressure of the hydrogen gas in the hydrogen supply passage 31 upstream of the injector 54 is "1 MPa or less". The assumed pressure of the hydrogen gas in the hydrogen supply passage 31, the exhaust drain passage 32, and the circulation passage 34 downstream of the injector 54 is "200 kPa or less".

[0024] On the other hand, the air system 22 is provided on the cathode side of the FC stack 11. This air system 22 includes an air supply passage 61 and an air discharge passage 62. The air supply passage 61 is a passage for supplying air from the outside of the fuel cell system 1 to the FC stack 11. The air discharge passage 62 is a passage for discharging the air (that is, air off-gas) discharged from the FC stack 11.

[0025] Furthermore, the air system 22 includes an air compressor 71 in the air supply passage 61. The air compressor 71 is an electrically powered device that supplies air to the FC stack 11. In this embodiment, no devices such as air valves are provided in the air supply passage 61 or the air discharge passage 62 between the air compressor 71 and the FC stack 11. In other words, in this embodiment, air is supplied directly to the FC stack 11 from the air compressor 71, and the air-off gas is discharged directly from the FC stack 11 to the outside.

[0026] [Regarding the operation of the fuel cell system] In the fuel cell system 1 configured as described above, the hydrogen supplied to the FC stack 11 from the hydrogen supply passage 31 is used for power generation in the FC stack 11, and then discharged from the FC stack 11 as hydrogen off-gas to the outside of the fuel cell system 1 via the exhaust and drainage passage 32. Similarly, the air supplied to the FC stack 11 from the air supply passage 61 is used for power generation in the FC stack 11, and then discharged from the FC stack 11 as air off-gas to the outside of the fuel cell system 1 via the air discharge passage 62.

[0027] The electricity generated by the FC stack 11 is either supplied to the battery to charge it, or supplied to the inverter to drive it. The inverter is also powered by the battery.

[0028] [Regarding the configuration of the hydrogen supply route] This embodiment has technical features in the configuration of the hydrogen supply passage 31. Figure 2 shows an enlarged view of a portion of the hydrogen system 21 in Figure 1. As shown in Figures 1 and 2, in this embodiment, the piping upstream of the injector 54 in the hydrogen supply passage 31 is made entirely of metal (shown as thick lines in Figures 1 and 2). Furthermore, all of the piping downstream of the injector 54 in the hydrogen supply passage 31 is made of resin (shown as solid lines in Figures 1 and 2).

[0029] [Regarding the operation and effects of fuel cell systems] As described above, with the configuration of this embodiment, the piping upstream of the injector 54 in the hydrogen supply passage 31 is made only of metal, so the rigidity of the hydrogen supply passage 31 is increased in that section. Furthermore, since at least a portion of the piping downstream of the injector 54 is made of resin, elasticity or flexibility is obtained in at least a portion of the hydrogen supply passage 31 in that section. As a result, strength can be ensured in the piping upstream of the injector 54 in the hydrogen supply passage 31, and flexibility can be ensured in the piping downstream of the injector 54 in the hydrogen supply passage 31. Consequently, the durability of the piping can be improved upstream of the injector 54 in the hydrogen supply passage 31, and the ease of assembly of the piping can be improved downstream of the injector 54 in the hydrogen supply passage 31.

[0030] As a result, the safety of the hydrogen supply passage 31 upstream of the injector 54 can be ensured. Furthermore, if abnormally high pressure is applied to the passage, the injector 54 can be closed to prevent high pressure from being applied downstream of the injector 54. This prevents damage to the resin piping downstream of the injector 54 and ensures safety.

[0031] On the other hand, cost reduction can be achieved for the hydrogen supply passage 31 downstream of the injector 54. In addition, since variations in pipe assembly can be absorbed, the ease of pipe assembly can be improved.

[0032] In contrast, if all the piping in the hydrogen supply passage 31 is made of metal, the cost will increase significantly. Also, because the piping lacks flexibility, the tolerance for assembly is small, and the ease of assembly will decrease. On the other hand, if all the piping in the hydrogen supply passage 31 is made of resin, the strength of the piping will be low, and there is a risk of damage to the piping when high pressure is applied. In addition, a large-diameter relief valve will be required to avoid high pressure conditions. In this embodiment, the above disadvantages can be avoided.

[0033] According to the configuration of this embodiment, since the entire piping downstream of the injector 54 in the hydrogen supply passage 31 is made of resin, elasticity or flexibility can be obtained in the entire hydrogen supply passage 31 in that section. Therefore, flexibility can be ensured in the piping throughout the entire hydrogen supply passage 31 downstream of the injector 54.

[0034] Furthermore, this disclosed technology is not limited to the embodiments described above, and it can be implemented by appropriately modifying a part of the configuration without departing from the spirit of the disclosed technology.

[0035] (1) In the above embodiment, all of the piping downstream of the injector 54 in the hydrogen supply passage 31 is made of resin, but it can also be made of rubber.

[0036] (2) In the above embodiment, all of the piping downstream of the injector 54 in the hydrogen supply passage 31 is made of resin, but a part of the piping may also be made of rubber or resin.

[0037] (3) In the above embodiment, an injector 54 was provided as a fuel adjustment device, but an LSV (linear solenoid valve) can also be provided as a fuel adjustment device. [Industrial applicability]

[0038] This disclosed technology can be used, for example, in fuel cell systems installed in electric vehicles. can. [Explanation of Symbols]

[0039] 1. Fuel cell system 11 FC Stack (Fuel Cell) 31. Hydrogen supply passage (fuel supply passage) 54 Injector (fuel adjustment device)

Claims

1. In a fuel cell system equipped with a fuel cell that generates electricity by receiving fuel and an oxidizer, A fuel supply passage for supplying the fuel to the fuel cell, A fuel adjustment device provided in the fuel supply passage for adjusting the amount of fuel supplied to the fuel cell, Equipped with, The piping upstream of the fuel adjustment device in the fuel supply passage is made of metal only, and at least a portion of the piping downstream of the fuel adjustment device is made of resin or rubber. A fuel cell system characterized by the following features.

2. In the fuel cell system according to claim 1, All of the piping downstream of the fuel adjustment device in the fuel supply passage is made of resin or rubber. A fuel cell system characterized by the following features.

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