JP2009140873A - Fuel cell system, and fuel cell vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress as much as possible flinging up of water contained in an off-gas from a fuel cell. <P>SOLUTION: The vehicle S mounted with a fuel cell system is provided with a fuel cell which generates power by electrochemical reaction of an oxidation gas and a fuel gas, and an exhaust pipe 100 to introduce off-gas exhausted from the fuel cell to the outside. The exhaust pipe 100 has an inner tube 101 of small diameter arranged concentrically at the discharge side end part arranged rearward at the rear part of the vehicle S. The inner circumference of the exhaust pipe 100 and the outer circumference of the inner tube 101 are connected at the discharge end side, and an opening 103 is formed at the upper part in gravity direction of the connecting portion 102 of the exhaust pipe 100 and the inner tube 101. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell system including a fuel cell that generates electricity by an electrochemical reaction between an oxidizing gas and a fuel gas, an exhaust pipe that guides off-gas from the fuel cell to the outside, and a fuel equipped with the fuel cell system It relates to battery cars.

As an exhaust pipe that guides exhaust gas from a drive source to the outside, there is a pipe that has a double pipe at its end to prevent oil from adhering to the muffler body and the vehicle body, and to enhance the noise reduction effect (for example, Patent Document 1). To 3).
By the way, in a fuel cell vehicle equipped with a fuel cell that generates electricity by an electrochemical reaction between an oxidizing gas and a fuel gas, water generated by the power generation is discharged together with the fuel off-gas and the oxidizing off-gas. For this reason, there is an exhaust pipe structure in this fuel cell vehicle that suppresses deterioration of the sound absorbing material due to water by discharging the water flowing in the exhaust pipe upstream of the muffler with a double exhaust pipe structure. (For example, refer to Patent Document 4).
JP-A-9-291816 JP 2000-320320 A Japanese Patent Laid-Open No. 10-252443 JP 2005-73463 A

  By the way, the water discharged from the exhaust pipe of the fuel cell vehicle flows in the exhaust pipe mixed with off-gas, and is dispersed into a plurality of droplets at the bent portion of the exhaust pipe, and then from the discharge side end to the outside. When it is discharged, it is blown up by the traveling wind flowing under the vehicle floor during traveling. For this reason, the appearance at the rear of the vehicle is poor, and water may scatter to the following vehicle.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fuel cell system and a fuel cell vehicle capable of suppressing ascending water contained in off-gas from the fuel cell as much as possible.

In order to achieve the above object, a fuel cell system of the present invention includes a fuel cell that generates electric power by an electrochemical reaction between an oxidizing gas and a fuel gas, and an exhaust pipe that guides off-gas discharged from the fuel cell to the outside. In the fuel cell system, the exhaust pipe is disposed concentrically at a discharge-side end portion of the off gas to the outside so as to form a predetermined gap between the exhaust pipe and the inner periphery of the exhaust pipe. Use of a connecting portion between the inner periphery of the exhaust pipe and the outer periphery of the inner pipe, having an inner pipe, and the inner periphery of the exhaust pipe and the outer periphery of the inner pipe on the discharge end side being connected over the entire circumference An opening is formed in the upper part of the gravity direction in the state.
In addition, a fuel cell vehicle according to the present invention includes a fuel cell system including a fuel cell that generates electric power by an electrochemical reaction between an oxidizing gas and a fuel gas, and an exhaust pipe that guides off-gas discharged from the fuel cell to the outside. In addition, the fuel cell vehicle uses the fuel cell as at least a part of a drive source, and the exhaust pipe is disposed at the end portion of the off-gas discharge side disposed rearward at the rear of the vehicle. And an inner pipe arranged concentrically so that a predetermined gap is formed between the inner circumference of the exhaust pipe and the inner circumference of the exhaust pipe and the outer circumference of the inner pipe on the discharge end side. Thus, an opening is formed in the upper part of the connecting portion between the inner circumference of the exhaust pipe and the outer circumference of the inner pipe in the direction of gravity.

According to these configurations, the off-gas discharged from the fuel cell is discharged to the outside from the inner pipe provided at the discharge side end portion to the outside of the exhaust pipe, while the water contained in the off-gas is After being dammed by the connecting part on the discharge end side and once stored in the gap between the inner periphery of the exhaust pipe and the outer periphery of the inner pipe, it is released from the opening formed at the upper part in the gravity direction of the connecting part on the discharge end side to the outside. Will be discharged.
In this way, even if the water in the off-gas is dispersed into a plurality of droplets in the circulation process of the exhaust pipe, the plurality of droplets are temporarily stored at the discharge side end and then discharged to the outside. As a result, in a fuel cell vehicle, it is possible to suppress the splashing of water due to the driving wind during driving as much as possible. Can do.
The discharge side end of the exhaust pipe may be inclined downward in the direction of gravity.
According to such a configuration, it is possible to more reliably perform concentration and temporary storage on the discharge end side of the water dispersed in the droplets.

  According to the fuel cell system of the present invention, it is possible to suppress ascending water contained in the offgas from the fuel cell as much as possible.

  First, the overall configuration of a fuel cell system for a fuel cell vehicle having an exhaust pipe according to the present invention will be described. This fuel cell system is an on-vehicle power generation system for a fuel cell vehicle (hereinafter referred to as vehicle S). In addition to the fuel cell system mounted on the vehicle, the fuel cell system is used for all moving objects such as ships, airplanes, trains, and walking robots. The present invention can also be applied to a system or a stationary fuel cell system in which the fuel cell is used as power generation equipment for buildings (housing, buildings, etc.).

  In the fuel cell system 1 shown in FIG. 1, air (outside air) as an oxidizing gas is supplied to the air supply port of the fuel cell 20 via the air supply path 71. The air supply path 71 is provided with an air filter A1 that removes particulates from the air, a compressor A3 that pressurizes the air, and a humidifier A21 that adds required moisture to the air. The air filter A1 is provided with an air flow meter (flow meter) (not shown) that detects the air flow rate. The compressor A3 is driven by a motor. This motor is driven and controlled by a control unit 50 described later.

  Air off-gas (oxidation off-gas) discharged from the fuel cell 20 is discharged to the outside through the exhaust path 72. The exhaust path 72 is provided with a pressure adjustment valve A4 and a humidifier A21. The pressure adjustment valve A4 functions as a pressure regulator (pressure reduction) that sets the supply air pressure to the fuel cell 20. The control unit 50 sets the supply air pressure and the supply air flow rate to the fuel cell 20 by adjusting the rotation speed of the motor that drives the compressor A3 and the opening area of the pressure adjustment valve A4.

  Hydrogen gas as the fuel gas is supplied from the hydrogen supply source 30 to the hydrogen supply port of the fuel cell 20 through the hydrogen supply path 74. The hydrogen supply source 30 corresponds to, for example, a high-pressure hydrogen tank, but may be a so-called fuel reformer, a hydrogen storage alloy, or the like.

  In the hydrogen supply path 74, a shutoff valve H100 that supplies or stops supplying hydrogen from the hydrogen supply source 30, a hydrogen pressure regulating valve H9 that adjusts the supply pressure of hydrogen gas to the fuel cell 20 by reducing the pressure, and the fuel cell 20 A shutoff valve H21 for opening and closing between the hydrogen supply port and the hydrogen supply path 74 is provided. As the hydrogen pressure regulating valve H9, for example, a pressure regulating valve that performs mechanical pressure reduction can be used. However, a valve whose opening degree is linearly or continuously adjusted by a pulse motor may be used.

  The hydrogen gas that has not been consumed in the fuel cell 20 is discharged as hydrogen offgas (fuel gas offgas) to the hydrogen circulation path 75 and returned to the downstream side of the hydrogen pressure regulating valve H9 in the hydrogen supply path 74. The hydrogen circulation path 75 includes a gas-liquid separator H42 that recovers moisture from the hydrogen off-gas, a drain valve H41 that recovers the recovered product water in a tank (not shown) outside the hydrogen circulation path 75, and a hydrogen pump that pressurizes the hydrogen off-gas. H50 is provided.

  The shut-off valve H21 closes the anode side of the fuel cell 20. The operation of the hydrogen pump H50 is controlled by the control unit 50. The hydrogen off-gas merges with the hydrogen gas in the hydrogen supply path 74 and is supplied to the fuel cell 20 for reuse. The shut-off valve H21 is driven by a signal from the control unit 50.

  The hydrogen circulation path 75 is connected to the exhaust path 72 on the downstream side of the humidifier A21 by the purge flow path 76 via the discharge control valve H51. The discharge control valve H51 is an electromagnetic shut-off valve, and operates according to a command from the control unit 50, whereby the hydrogen off-gas is discharged (purged) together with the air off-gas discharged from the fuel cell 20. By performing this purge operation intermittently, it is possible to prevent a cell voltage from being lowered due to an increase in the impurity concentration in the hydrogen gas.

  A cooling path 73 for circulating the cooling water is provided at the cooling water inlet / outlet of the fuel cell 20. The cooling path 73 is provided with a radiator (heat exchanger) C2 that radiates heat of the cooling water to the outside, and a pump C1 that pressurizes and circulates the cooling water. The radiator C2 is provided with a cooling fan C13 that is rotationally driven by a motor.

  The fuel cell 20 is configured as a fuel cell stack in which a required number of single cells that receive supply of hydrogen gas and air and generate electric power through an electrochemical reaction are stacked. The electric power generated by the fuel cell 20 is supplied to a power control unit (not shown). The power control unit consists of an inverter that supplies electric power to the drive motor of the vehicle, an inverter that supplies electric power to various auxiliary devices such as a compressor motor and a motor for a hydrogen pump, and charging of power storage means such as a secondary battery. A DC-DC converter or the like that supplies power to the motors from the power storage means is provided.

  The control unit 50 is configured by a control computer system having a known configuration such as a CPU, ROM, RAM, HDD, input / output interface, display, and the like, and a required load such as an accelerator signal of a vehicle (not shown) and each part of the fuel cell system 1 Control information is received from these sensors (pressure sensor, temperature sensor, flow sensor, output ammeter, output voltmeter, etc.), and the operation of valves and motors in each part of the system is controlled.

As shown in FIGS. 2 and 4, the exhaust path 72 is composed of the exhaust pipe 100, and the discharge side end portion to the outside is disposed rearward at the rear portion of the vehicle S, and further the discharge side end portion. It is bent in the vicinity of the part and is directed slightly downward in the direction of gravity. In this exhaust pipe 100, a cylindrical inner pipe 101 is provided concentrically at the discharge side end so that a predetermined gap 110 is formed between the inner circumference of the exhaust pipe 100, The outer circumference of the inner pipe 101 and the inner circumference of the exhaust pipe 100 on the discharge end side are connected over the entire circumference.
As shown in FIGS. 3 and 4, an opening 103 is formed at the upper portion in the gravitational direction at the connecting portion 102 between the outer periphery of the inner pipe 101 and the inner periphery of the exhaust pipe 100. Except for being blocked. That is, the gap 110 between the inner pipe 101 and the exhaust pipe 100 communicates with the outside through the opening 103.

In the fuel cell system 1 mounted on the vehicle S, the off gas sent to the exhaust path 72 passes through the exhaust pipe 100 constituting the exhaust path 72 and is discharged from the inner pipe 101 to the outside at the discharge end. .
Further, in the exhaust pipe 100, as shown by the arrow in FIG. 2, water from the fuel cell 20 discharged together with the off gas flows, and at the discharge end, the exhaust pipe 100 is dammed by the connecting portion 102. Once accumulated in the gap 110 between the exhaust pipe 100 and the inner pipe 101, and then discharged to the outside through an opening 103 formed in the upper part in the gravity direction of the connecting part 102 between the exhaust pipe 100 and the inner pipe 101.

As described above, according to the fuel cell system 1 including the exhaust pipe 100 having the above-described configuration, even if water in the off-gas is dispersed into a plurality of droplets in the flow process of the exhaust pipe 100, The liquid droplets are temporarily stored at the discharge side end and then discharged to the outside. Further, since the discharge side end of the exhaust pipe 100 is inclined downward in the direction of gravity, the concentration and temporary storage on the discharge end side of the water dispersed in the droplets are more reliably performed.
Therefore, according to the vehicle S on which the fuel cell system 1 is mounted, it is possible to suppress ascending water by the traveling wind during traveling as much as possible, to improve the appearance of the rear of the vehicle S, and further to the subsequent vehicle. Water scattering can be suppressed.

It is a block diagram of the fuel cell system mounted in the fuel cell vehicle. It is a schematic sectional side view explaining the structure of the exhaust pipe which comprises the exhaust path shown in FIG. It is a front view of the rear end side of the exhaust pipe explaining the structure of the exhaust pipe. FIG. 3 is an enlarged view of a main part of the exhaust pipe shown in FIG. 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 20 ... Fuel cell, 100 ... Exhaust pipe, 101 ... Inner pipe, 102 ... Connection part, 103 ... Opening part, 110 ... Gap, S ... Vehicle (fuel cell vehicle).

Claims (4)

A fuel cell system comprising: a fuel cell that generates electricity by an electrochemical reaction between an oxidizing gas and a fuel gas; and an exhaust pipe that guides off-gas discharged from the fuel cell to the outside.
The exhaust pipe has an inner pipe arranged concentrically so that a predetermined gap is formed between the end of the off-gas to the outside discharge side and the inner periphery of the exhaust pipe, and the discharge end The inner circumference of the exhaust pipe on the side and the outer circumference of the inner pipe are connected over the entire circumference,
A fuel cell system in which an opening is formed at an upper portion in the direction of gravity when the connecting portion between the inner periphery of the exhaust pipe and the outer periphery of the inner tube is used. The fuel cell system according to claim 1,
A fuel cell system in which a discharge side end of the exhaust pipe is inclined downward in the direction of gravity. A fuel cell system comprising: a fuel cell that generates electricity by an electrochemical reaction between an oxidizing gas and a fuel gas; and an exhaust pipe that guides off-gas discharged from the fuel cell to the outside. A fuel cell vehicle used as a part,
The exhaust pipe is disposed concentrically so that a predetermined gap is formed between the exhaust gas and the inner periphery of the off-gas discharge side end disposed rearward at the rear of the vehicle. And having an inner pipe, and the inner circumference of the exhaust pipe on the discharge end side and the outer circumference of the inner pipe are connected over the entire circumference,
A fuel cell vehicle in which an opening is formed at an upper portion in a gravity direction of a connecting portion between an inner circumference of the exhaust pipe and an outer circumference of the inner pipe. The fuel cell vehicle according to claim 3, wherein
The discharge-side end of the exhaust pipe is a fuel cell vehicle that is inclined downward in the direction of gravity.

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