JP4269270B2 - Vehicle fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase a power generation capacity, by extending the bottom part of a fuel cell stack near the bottom part of a vehicle, and to facilitate discharging of generated water from the fuel cell stack as a hydrogen gas circulation path, extended to the rear of a vehicle from the bottom part of the fuel cell stack and an oxygen off gas discharge path will not be bent under the effect of a drive shaft. <P>SOLUTION: A travelling motor and a fuel cell stack are mounted in the width direction of a vehicle with a gear box that drives a front wheel in between via a drive shaft. The fuel cell stack and the drive shaft are arranged on the front side, and the hydrogen gas circulating path, connected to the bottom part of the fuel cell stack and the oxygen off gas discharge path, are extended to the rear of a vehicle through the lower side of the drive shaft. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to a vehicular fuel cell system, and more particularly to a vehicular fuel cell system that proposes an on-vehicle strategy for a fuel cell stack that is optimal for a front-wheel drive vehicle.

  In a fuel cell system mounted on a vehicle, the fuel cell is composed of, for example, a polymer electrolyte fuel cell, and the polymer electrolyte fuel cell is also referred to as a polymer ion exchange membrane (also referred to as “cation exchange membrane”). An electrolyte membrane / electrode structure in which an anode side electrode and a cathode side electrode are opposed to each other on both sides of the electrolyte membrane is composed of a separator.

  This type of fuel cell is usually used as a fuel cell stack by stacking a predetermined number of electrolytes (also referred to as “electrolyte membranes”), electrode structures, and separators.

  In the fuel cell system, air in the atmosphere is taken in as an oxidizing gas and supplied to the fuel cell. The supplied oxidizing gas is subjected to an electrochemical reaction using a catalyst in the fuel cell and then discharged as an oxygen off gas. The discharged oxygen off gas is then exhausted into the atmosphere outside the vehicle.

JP 2000-30725 A Japanese Patent Laid-Open No. 2002-373797 JP 2003-173790 A

  By the way, in the conventional vehicle fuel cell system, when a traveling motor, a gear box, and a fuel cell stack are mounted on the front portion of the vehicle, the above-mentioned Patent Document 2 (Japanese Patent Laid-Open No. 2002-373797) or Patent Document 3 (Japanese Patent Application Laid-Open No. 2003-173790), the fuel cell stack is disposed on the upper part of the traveling motor or gear box, so that the front box of the vehicle, the so-called engine room, can be There is an inconvenience of increasing the size in the direction.

  Accordingly, in order to eliminate the above-described disadvantages, the present invention provides a vehicle fuel cell system in which a travel motor and a fuel cell stack are mounted with a gear box driving a front wheel via a drive shaft in the width direction of the vehicle. The fuel cell stack is disposed on the front side of the drive shaft, and a hydrogen gas circulation passage and an oxygen off-gas discharge passage connected to the lower end of the fuel cell stack are extended rearward of the vehicle through the lower side of the drive shaft. It is characterized by having put out.

  As described above in detail, according to the present invention, in a vehicle fuel cell system in which a traveling motor and a fuel cell stack are mounted with a gear box driving a front wheel through a drive shaft in the width direction of the vehicle. The fuel cell stack is arranged on the front side of the drive shaft, and the hydrogen gas circulation passage and the oxygen off-gas discharge passage connected to the lower end of the fuel cell stack are extended to the rear of the vehicle through the lower side of the drive shaft. The power generation capacity can be expanded by extending the lower end of the battery stack to the vicinity of the lowermost part of the vehicle, and the hydrogen gas circulation passage and the oxygen off-gas discharge passage extending from the lower end of the fuel cell stack to the rear of the vehicle It is not bent by the influence of the shaft, and the generated water can be easily discharged from the fuel cell stack.

  By inventing as described above, the fuel cell stack is disposed on the front side of the drive shaft, and the hydrogen gas circulation passage and the oxygen off-gas discharge passage connected to the lower end of the fuel cell stack are passed through the lower side of the drive shaft. Extends backward, extends the lower end of the fuel cell stack to the vicinity of the bottom of the vehicle to expand the power generation capacity, and extends the hydrogen gas circulation channel and oxygen off-gas discharge extending from the lower end of the fuel cell stack to the rear of the vehicle The flow path is not curved by the influence of the drive shaft, and the generated water is easily discharged from the fuel cell stack.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  1 to 7 show an embodiment of the present invention. In FIG. 7, reference numeral 2 denotes a fuel cell system.

  As shown in FIG. 7, the fuel cell system 2 includes a fuel cell stack 4, a hydrogen system 6, an air system 8, and a cooling system 10.

  The fuel cell stack 4 is usually formed by laminating a predetermined number of electrolytes (also referred to as “electrolyte membranes”), electrode structures, and separators.

  Further, the hydrogen system 6 is provided with a hydrogen gas circulation passage 14 for supplying and circulating hydrogen to the fuel cell stack 4 from a hydrogen tank 12 mounted on a vehicle 46 described later.

  The hydrogen gas circulation channel 14 includes a hydrogen supply first channel 16 for supplying hydrogen from the hydrogen tank 12 to the fuel cell stack 4, and a hydrogen off-gas exhausted from the fuel cell stack 4 in the first flow. The second flow path 18 for circulation to be circulated through the path 16 and the third flow path 20 for discharge that discharges hydrogen off-gas connected to a part of the second flow path 18.

  And in the middle of the first flow path 16 for supplying hydrogen, an automatic shut-off valve 22, a pressure reducing valve 24, a flow rate adjusting valve 26, and a heat exchanger 28 are sequentially arranged from the hydrogen tank 12 side, A gas-liquid separator 30 and a circulation pump 32 are sequentially disposed in the middle of the second flow path 18 for circulation from the fuel cell stack 4 side, and the downstream end is heat exchanged with the flow rate adjusting valve 26. And connected to the first flow path 16 for supplying hydrogen between the gas generator 28 and the third flow path 20 for exhaust between the gas-liquid separator 30 and the circulation pump 32. The pressure regulating valve 34 is disposed in the middle of the third flow path 20.

  Further, the air system 8 includes an oxidizing gas supply flow path 36 for supplying an oxidizing gas to the fuel cell stack 4 from the outside, and an oxygen off gas discharge flow path 38 for discharging the oxygen off gas from the fuel cell stack 4 to the outside. Have.

  A filter 40, a pump 42, and a heat exchanger 44 are sequentially disposed in the middle of the oxidizing gas supply flow path 36 from the upstream side, and a gas liquid is disposed in the middle of the oxygen off-gas discharge flow path 38. A separator 46 and a pressure regulating valve 48 are sequentially arranged.

  When the fuel cell system 2 is mounted in the engine room 52 of the vehicle 50, as shown in FIGS. 2 to 5, left and right extending in the width direction of the vehicle 50 so as to communicate with the left and right front wheels 54, 54 of the vehicle 50. Drive shafts 56-1 and 56-2 are provided, and a gear box 58 for driving both front wheels 54 and 54 via the drive shafts 56-1 and 56-2 is disposed at a central portion. Is mounted on the right side of the gear box 58 and the fuel cell stack 4 is mounted on the left side of the gear box 58.

  As shown in FIGS. 5 and 6, the fuel cell stack 4 is mounted with the upper side of the fuel cell stack 4 inclined toward the rear side of the vehicle 50. The inclination angle is set in the range of 3 to 45 degrees.

  Furthermore, a hydrogen tank 12 that functions as a fuel tank for the vehicle 50 is mounted on the rear portion of the vehicle 50.

  At this time, as shown in FIG. 5, the fuel cell stack 4 is disposed in front of the drive shafts 56-1 and 56-2 and connected to the lower end of the fuel cell stack 4 for circulating the hydrogen off-gas. As shown in FIG. 1, the second flow path 18 and the oxygen off-gas discharge flow path 38 are configured to extend rearward of the vehicle through the lower sides of the drive shafts 56-1 and 56-2.

  More specifically, at least one of the second flow path 18 for circulating hydrogen off-gas and the oxygen off-gas discharge flow path 38 has a gas-liquid separator 30 at a position close to the rear side of the left drive shaft 56-1. 46 are interposed.

  Further, as shown in FIG. 6, the gas-liquid separators 30 and 46 are outlet side tubes 62 and 64 that constitute a part of the second flow path 18 for circulating hydrogen off-gas or the oxygen off-gas discharge flow path 38, respectively. Are respectively supported by the fuel cell stack 4.

  Further, as shown in FIG. 1, the outlet side pipes 62 and 64 are curved on the downstream side of the passage toward the center side in the vehicle width direction, and the gas-liquid separators 30 and 46 are connected to those shown in FIGS. As shown, it is disposed near the gear box 58.

  Reference numerals 66 and 66 are the left and right rear wheels of the vehicle 50, 68 is a cooling water pipe disposed near the gear box 58, and 70 and 72 are the first flow path 16 for supplying the hydrogen gas or An inlet-side tube body 74 constituting a part of the oxygen gas supply channel 36 is a radiator for the fuel cell stack 4.

  Next, the operation will be described.

  As shown in FIG. 5, the fuel cell stack 4 is disposed in front of the drive shafts 56-1 and 56-2 and connected to the lower end of the fuel cell stack 4 for the second flow for the hydrogen off-gas circulation. As shown in FIG. 1, the passage 18 and the oxygen off-gas discharge passage 38 extend rearward of the vehicle through the lower side of the drive shafts 56-1 and 56-2.

  At least one of the second flow path 18 for circulating hydrogen off-gas and the oxygen off-gas discharge flow path 38 is provided with gas-liquid separators 30 and 46 at positions close to the rear side of the left drive shaft 56-1. Interpose.

  As a result, the fuel cell stack 4 is arranged in front of the drive shafts 56-1 and 56-2, and the second flow path 18 for circulating hydrogen off-gas connected to the lower end of the fuel cell stack 4 and the oxygen are connected. By extending the off-gas discharge passage 38 to the rear of the vehicle through the lower side of the drive shafts 56-1 and 56-2, the lower end portion of the fuel cell stack 4 is extended to the vicinity of the lowermost portion of the vehicle 50 to generate power. The capacity can be increased, and the hydrogen gas circulation flow path 14 and the oxygen off-gas discharge flow path 38 extending from the lower end of the fuel cell stack 4 to the rear of the vehicle are curved by the influence of the drive shafts 56-1 and 56-2. The generated water from the fuel cell stack 4 can be easily discharged.

  Further, at least one of the second flow path 18 for circulating hydrogen off-gas and the oxygen off-gas discharge flow path 38 is provided with gas-liquid separators 30 and 46 at positions close to the rear side of the left drive shaft 56-1. By interposing, the gas-liquid separators 30 and 46 are disposed at a low position of the vehicle while effectively utilizing the space around the left drive shaft 56-1, and the gas-liquid separator 30 is removed from the fuel cell stack 4. , 46 is easily discharged.

  Further, the gas-liquid separators 30 and 46 are connected to the fuel cell via outlet side pipes 62 and 64 that constitute a part of the second flow path 18 for circulating the hydrogen off gas or the oxygen off gas discharge flow path 38. Supporting each of the stacks 4 simplifies the support measures for the gas-liquid separators 30 and 46, that is, eliminates the need for a support member dedicated to the gas-liquid separators 30 and 46, and also allows the outlet-side tubes 62 and 64 and The liquid separators 30 and 46 can be easily positioned on the drive shafts 56-1 and 56-2 through a predetermined gap.

  Furthermore, the outlet side pipes 62 and 64 are curved on the downstream side of the passage toward the center in the vehicle width direction, and the gas-liquid separators 30 and 46 are disposed in the vicinity of the gear box 58, thereby The liquid separators 30 and 46 can be disposed in the vicinity of the gear box 58 at a position where the drive shafts 56-1 and 56-2 are less oscillated or do not interfere with each other, which is practically advantageous.

  Further, the mounting position of the fuel cell stack 4 on the vehicle 50 is lowered to contribute to the downsizing of the front box of the vehicle 50, the so-called engine room 52.

It is a schematic explanatory drawing of the state which looked at the fuel cell stack mounted in the vehicle which shows the Example of this invention from the downward direction. It is a schematic left view of the vehicle carrying a fuel cell stack. It is a schematic plan view of the vehicle carrying a fuel cell stack. It is a general | schematic enlarged plan view of the engine room part located in a vehicle front part. It is a principal part enlarged left view of the vehicle of the state which mounted the fuel cell in the engine room part of the vehicle front part. It is the schematic which shows the attachment state of a fuel cell stack and a gas-liquid separator. It is a schematic explanatory drawing of a fuel cell system.

Explanation of symbols

2 Fuel cell system 4 Fuel cell stack 6 Hydrogen system 8 Air system 10 Cooling system 12 Hydrogen tank 14 Hydrogen gas circulation channel 16 First channel 18 Second channel 20 Third channel 22 Automatic shut-off valve 24 Pressure reducing valve 26 Flow Control Valve 28 Heat Exchanger 30 Gas-Liquid Separator 32 Circulation Pump 34 Pressure Adjustment Valve 36 Oxidizing Gas Supply Flow Path 38 Oxygen Off Gas Discharge Flow Path 40 Filter 42 Pump 44 Heat Exchanger 46 Gas-Liquid Separator 48 Pressure Control Valve 50 Vehicle 52 Engine room 54, 54 Left and right front wheels 56-1, 56-2 Left and right drive shafts 58 Gear box 60 Traveling motors 62, 64 Exit side pipe bodies 66, 66 Both left and right rear wheels 68 of the vehicle 68 Cooling water piping 70, 72 Inlet side pipe body 74 Radiator

Claims (4)

  In a vehicle fuel cell system in which a traveling motor and a fuel cell stack are mounted with a gear box driving a front wheel through a drive shaft in the width direction of the vehicle, the fuel cell stack is disposed on the front side of the drive shaft. A fuel cell system for a vehicle, wherein a hydrogen gas circulation passage and an oxygen off-gas discharge passage connected to the lower end of the fuel cell stack are extended to the rear of the vehicle through the lower side of the drive shaft.   2. The vehicle according to claim 1, wherein a gas-liquid separator is interposed in a position close to a rear side of the drive shaft in at least one of the hydrogen gas circulation passage and the oxygen off-gas discharge passage. Fuel cell system.   3. The vehicle according to claim 2, wherein the gas-liquid separator is supported by the fuel cell stack via a pipe body that forms part of the hydrogen gas circulation passage or the oxygen off-gas discharge passage. Fuel cell system.   4. The vehicle fuel cell system according to claim 3, wherein the pipe body is curved at the downstream side of the passage toward the center in the vehicle width direction, and the gas-liquid separator is disposed in the vicinity of the gear box.

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