JP2008241008A - Pipe fitting, piping structure, and fuel cell system fitted with them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe fitting of simple construction capable of securing the electrical insulating performance while the space required to install the piping is suppressed, and provide a piping structure and also a fuel cell system fitted with them. <P>SOLUTION: An upstream piping 75 and downstream piping 83 of a hydrogen circulating passage 75 are coupled together by a cylindrical pipe fitting 83, for example formed from an insulating material such as rubber. The pipe fitting 83 is formed in such a way that the middle part is nipped narrow to allow grasping, whereby a different diameter portion 83a with the inside diameter reduced with respect to the other portions is formed in the middle of the pipe fitting 83, whereby the produced water W can flow intermittently. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe joint, a pipe structure, and a fuel cell system including these.

In recent years, a fuel cell vehicle using a fuel cell that generates power by an electrochemical reaction between a fuel gas and an oxidizing gas as an energy source has attracted attention.
And in the fuel cell system provided in this fuel cell vehicle etc., piping for supplying and exhausting reaction gas such as fuel gas and oxidant gas to the fuel cell is connected.

By the way, in the piping structure connected to the fuel cell, electrical insulation is ensured by interposing an insulating material such as an insulating rubber hose. In this case, in order to ensure sufficient insulation resistance, a measure to lengthen the rubber hose may be taken. Or the technique which made the diameter of a downstream pipe larger than the diameter of an upstream pipe, or provided the taper nozzle in the upstream pipe so that insulation performance may not fall is also disclosed (for example, patent document 1, 2).
JP-A-8-329970 JP-A-11-82834

  However, due to the space of the piping, it may be difficult to make the rubber hose sufficiently long. In such a case, the water flowing in the rubber hose (for example, the generated water of the fuel cell) is connected to the upstream and downstream piping ends. There is a possibility that the insulation performance is lowered due to the electrical connection. In addition, it is troublesome to change the diameter of the pipe or provide the nozzle, and the structure becomes complicated.

  The present invention has been made in view of such circumstances, and has a simple structure of a pipe joint, a pipe structure, and a fuel cell including these, capable of ensuring insulation performance while suppressing a space required for pipe installation. The purpose is to provide a system.

  In order to achieve the above object, the present invention provides a pipe joint made of an insulating material connected to an upstream side pipe and a downstream side pipe, wherein a different-diameter portion narrower than the diameter in the vicinity of both end portions is provided between the both end portions. Have.

According to this configuration, the flow of generated water that flows inside the different diameter portion can be discontinuous. According to this, it can suppress that the water which flows through the said piping joint will be in the state electrically connected with the upstream and downstream piping edge part, and can suppress the fall of insulation performance.
Thereby, the insulation performance can be ensured without increasing the length of the insulating hose in the axial direction and with a simple structure.

  The pipe joint may be provided with a throttle member for constricting the different diameter portion.

  The piping structure according to the present invention is formed by connecting an upstream piping and a downstream piping by the above-described piping joint.

  In the present invention, the upstream side pipe, the pipe joint, and the downstream side pipe are arranged in the vertical direction.

  Furthermore, the fuel cell system according to the present invention includes the above-described piping structure. It is preferable that the piping connected to the fuel cell that generates power by reaction of the reaction gas is constituted by the piping structure.

  ADVANTAGE OF THE INVENTION According to this invention, the space required for installation of piping can be suppressed, and insulation performance can be ensured, implement | achieving a simple structure.

  First, an overall configuration of a fuel cell system to which a pipe joint and a pipe structure according to the present invention are applied will be described. This fuel cell system is an in-vehicle power generation system for a fuel cell vehicle. In addition to a fuel cell system mounted on a vehicle, a fuel cell system for any moving body such as a ship, an aircraft, a train, a walking robot, or the like, for example, a fuel cell However, it can also be applied to stationary fuel cell systems used as power generation equipment for buildings (housing, buildings, etc.).

  In the fuel cell system 1 shown in FIG. 1, air (outside air, humidified gas) as an oxidizing gas is supplied to an air supply port of the fuel cell 20 via an 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, humidified 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 intermittently performing this purging operation, it is possible to prevent the cell voltage from decreasing 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 hydrogen pump motor, 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 3, the humidifier A <b> 21 is discharged outside from the compressor A <b> 3 to the fuel cell 20 through the air supply path 71 (humidified gas) and from the fuel cell 20 through the exhaust path 72. Moisture exchange is performed with air off-gas (humidified gas) to add moisture to the air. The humidifier A21 includes a humidification module and a casing that houses the humidification module.

Next, the piping structure 8 of the fuel cell system 1 according to the present embodiment will be described with reference to FIG.
Here, a description will be given by taking, as an example, piping of a hydrogen circulation path 75 through which hydrogen off-gas from the fuel cell 20 flows.

  As shown in FIG. 2A, an insulating hose 83 is provided as a joint between an upstream side pipe 81 and a downstream side pipe 82 made of metal pipes in a portion arranged along the vertical direction of the hydrogen circulation path 75. The upstream pipe 81 and the downstream pipe 82 are connected by the insulating hose 83 to connect the flow paths.

The insulating hose 83 is made of, for example, an insulating material such as rubber formed in a cylindrical shape. The insulating hose 83 is fitted with an upstream pipe 81 at one end 83b and downstream at the other end 83c. A pipe 82 is fitted.
And the connection location of the upstream side piping 81 and the downstream side piping 82 with respect to this insulation hose 83 is fixed by the clip 85, and is in an airtight state.

  As shown in FIG. 2 (b), the insulating hose 83 is formed by narrowing the body portion so that the middle portion thereof is constricted (constricted), thereby forming a different diameter portion 83a. That is, in this insulating hose 83, the cross-sectional area of the flow path is reduced from both ends toward the intermediate diameter portion 83a.

  In the hydrogen circulation path 75 provided with such an insulating hose 83, when the hydrogen off-gas discharged from the fuel cell 20 flows, the generated water W generated in the fuel cell 20 flows along with the hydrogen off-gas.

The generated water W that flows along with the hydrogen off-gas is intermittently flowed in the insulating hose 83 in which the cross-sectional area of the flow path is changed by forming the different diameter portion 83a.
That is, the flow of the generated water W flowing through the inside of the insulating hose 83 is intermittent and becomes discontinuous, thereby reducing the insulation performance due to the generated water W flowing over the upstream pipe 81 and the downstream pipe 82. Can be suppressed.

As described above, according to the embodiment in which the body portion of the insulating hose (pipe joint) 83 is narrowed, drainage of the generated water W can be promoted. Furthermore, according to this embodiment, the flow of the generated water W in the piping such as the hydrogen circulation path 75 is intermittently generated at the different diameter portion 83 a of the insulating hose 83, and the generated water extends over the upstream side piping 81 and the downstream side piping 82. A decrease in insulation performance due to the flow of W can be suppressed.
Thereby, good insulation performance can be secured without increasing the length of the insulating hose 83 in the axial direction.

  And according to the fuel cell system 1 provided with this piping structure 8, since the favorable insulation performance in piping is ensured, it can be set as the fuel cell system 1 which is excellent in insulation performance and is safer. .

  In the above embodiment, the different diameter portion 83a is formed by molding so that the intermediate portion of the insulating hose 83 is constricted. However, the intermediate portion of the insulating hose 83 having the same diameter in the longitudinal direction is shown in FIG. In addition, the different-diameter portion 83 a constricted by being squeezed by the clip 86 may be formed. In such a case, since the different diameter portion 83a can be formed using the clip 86, it is not necessary to form the insulating hose 83 in a constricted shape in advance.

In the above embodiment, the hydrogen circulation path 75 has been described as an example. However, the piping structure 8 of the present invention is not limited to the hydrogen circulation path 75 and can be applied to other piping.
Furthermore, the formation position and the number of the different diameter portions 83a are not limited to the above embodiment, and the material of the insulating hose 83 may be an insulating material, not limited to rubber, but also an insulating material such as plastic. Material may be used.

1 is a system configuration diagram schematically showing a fuel cell system according to an embodiment of the present invention. It is a figure explaining the piping structure of the hydrogen circulation path of a fuel cell system, (a) is a side view in an insulating hose part, (a) is a sectional view in an insulating hose part. It is a side view in the insulation hose part explaining the other piping structure of the hydrogen circulation path of a fuel cell system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel cell system, 8 ... Piping structure, 20 ... Fuel cell, 75 ... Hydrogen circulation path (piping), 81 ... Upstream piping, 82 ... Downstream piping, 83 ... Insulation hose (piping joint), 83a ... Different Diameter part, 83b, 83c ... end part, 86 ... clip (throttle member).

Claims (6)

In a pipe joint made of an insulating material connected to the upstream pipe and the downstream pipe,
The pipe joint which has the different diameter part narrowed rather than the diameter of the both ends vicinity between the said both ends.   The piping joint according to claim 1, wherein a throttle member for constricting the different diameter portion is provided.   A pipe structure in which an upstream pipe and a downstream pipe are connected by the pipe joint according to claim 1.   The piping structure according to claim 3, wherein the upstream pipe, the pipe joint, and the downstream pipe are arranged in a vertical direction.   A fuel cell system comprising the piping structure according to claim 3 or 4.   The fuel cell system according to claim 5, wherein a pipe connected to a fuel cell that generates electric power by reaction of a reaction gas is constituted by the pipe structure.

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