JP5920240B2 - Fuel cell piping, fuel gas discharging method and connecting pipe - Google Patents

Description

  The present invention relates to the discharge of fuel gas.

  The fuel gas used for power generation of the fuel cell may be released to the atmosphere. When a fuel gas is discharged in a vehicle fuel cell, a method is known in which the gas concentration is diluted from the vicinity of the rear end of the vehicle toward the rear while being diluted from the exhaust pipe for air (for example, Patent Document 1).

JP 2010-015848 A

  The problem of the prior art is that when high-pressure fuel gas is discharged, high-concentration fuel gas may be released to the rear of the vehicle (behind the rear end of the vehicle). When discharging the high-pressure fuel gas, the fuel gas is guided to the vicinity of the rear end of the vehicle by the exhaust pipe, and then released to the atmosphere toward the rear of the vehicle. For this reason, when there is not enough air in the exhaust pipe, high-concentration fuel gas may be released to the rear of the vehicle.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one aspect of the present invention, a fuel cell pipe mounted on a vehicle is provided. The pipe includes a fuel gas supply pipe for supplying fuel gas to the fuel cell; and a gas pressure in the fuel gas supply pipe when the gas pressure, which is a pressure in the fuel gas supply pipe, reaches or exceeds a first reference value. Is discharged from an outlet installed near the rear end of the vehicle, and the gas pressure reaches a second reference value greater than the first reference value, the vehicle is below the floor of the vehicle and forward of the vehicle than the exhaust port. And a discharge part for discharging the gas in the fuel gas supply pipe. According to this aspect, when discharging high-pressure fuel gas, it is possible to reduce the possibility that high-concentration fuel gas is released to the rear of the vehicle. This is because when the pressure of the fuel gas reaches a high pressure (second reference value or higher), the fuel gas is discharged below the floor of the vehicle and ahead of the vehicle from the discharge port. When discharged in this way, the fuel gas is sufficiently mixed with the air outside the vehicle before reaching the vicinity of the rear end of the vehicle. As a result, the above effect can be obtained.

(2) In the above embodiment, the discharge part is; a safety valve provided in the fuel gas supply pipe; an exhaust pipe that includes the discharge port and discharges fluid other than fuel gas; and an exhaust pipe with respect to the exhaust pipe A connection pipe that is connected at a connection site and that forms a connection flow path connecting the safety valve and the exhaust pipe by being connected to the safety valve; and the gas pressure reaches the first reference value or more. In this case, when the safety valve is activated, the fuel gas is discharged through the connection pipe and the exhaust pipe; and when the gas pressure reaches the second reference value or more, the connection flow path becomes the gas By being damaged by pressure, the fuel gas is discharged without going through the exhaust pipe. According to this form, the previous form can be realized by a simple method of adding a connecting pipe.

(3) In the above embodiment, when the gas pressure reaches the second reference value or higher, the connection pipe and the safety valve are disconnected. This form simplifies the design. The connection part between the connection pipe and the safety valve is a part having a high gas pressure in the connection pipe. If the connection is disconnected at the part where the gas pressure is high, the design becomes simpler than the method of disconnecting at the other part.

(4) In the above embodiment, a clamping member is provided for fixing the connection pipe to the safety valve by applying a clamping force to the connection pipe; the gas pressure is equal to or higher than the second reference value. Is reached by the force received through the connecting pipe. According to this aspect, it is possible to realize that the connection is damaged by the force of the gas pressure equal to or higher than the second reference value by a simple method.

(5) In the above aspect, the safety valve is disposed above the exhaust pipe connection portion. According to this aspect, since it is possible to suppress water droplets or the like from reaching the safety valve through the connection pipe from the exhaust pipe, it is possible to suppress malfunction caused by freezing of the safety valve.

(6) In the above embodiment, the safety valve has an opening facing downward. According to this aspect, when the connection pipe is disconnected, the gas in the fuel gas supply pipe is discharged downward, so that safety is further improved.

(7) In the above aspect, the safety valve is disposed closer to the center in the left-right direction than the exhaust pipe connection portion. According to this aspect, it is possible to suppress the gas exhausted from the safety valve from being vigorously diffused outside the vehicle. This is because the exhaust pipe is disposed between the gas discharged downward from the safety valve and the outside of the vehicle. The left-right direction is a direction orthogonal to the traveling direction of the vehicle and the vertical direction.

(8) In the above aspect, the safety valve is disposed upstream of the exhaust pipe connection site. According to this aspect, since the outflow of water droplets or the like from the connection pipe to the exhaust pipe is promoted, it is possible to suppress the malfunction caused by the freezing of the safety valve.

(9) In the above aspect, the connection pipe forms a bent flow path. According to this aspect, it is possible to suppress water droplets or the like from reaching the safety valve via the connection pipe from the exhaust pipe, and therefore, it is possible to suppress malfunction due to icing of the safety valve.

(10) In the above aspect, the exhaust pipe connection portion is opened when fluid other than the fuel gas is discharged from the exhaust pipe. According to this aspect, since the connecting pipe functions as a side branch of the exhaust pipe, pulsation in the exhaust pipe is suppressed.

(11) In the above aspect, a detection unit that detects that fuel gas is discharged in front of the vehicle and below the floor of the vehicle from the discharge port is provided. According to this aspect, when the gas in the fuel gas supply pipe is discharged in front of the vehicle and below the floor of the vehicle, it is possible to take measures such as closing the main stop valve of the fuel gas tank. Become.

  The present invention can be realized in various forms other than the above. For example, it can be realized in the form of a method of discharging fuel gas from a fuel cell system mounted on a vehicle, a connection pipe as a part of the fuel cell pipe, a fuel cell system including the fuel cell pipe, and the like.

The perspective view of a fuel cell system. The perspective view of a connection pipe vicinity. The figure which shows the cross section of a 1st site | part, a clip, and a safety valve, and a regulator. The figure which shows a mode that the connection pipe removed from the safety valve.

  FIG. 1 is a perspective view of the fuel cell system 10. The fuel cell system 10 is mounted on a fuel cell vehicle (hereinafter referred to as “vehicle”). The coordinate axes shown in FIG. 1 indicate directions on the basis of up and down, left and right, and front and rear of the vehicle. In this specification, all directions are described according to the coordinate axes.

  The fuel cell system 10 includes a fuel cell 100, two hydrogen tanks 110, a first hydrogen supply pipe 121, a second hydrogen supply pipe 122, a third hydrogen supply pipe 123, a regulator 130, and a supply A side manifold 135, a hydrogen filling pipe 140, a filling side manifold 150, and an exhaust / drain pipe 160 are provided.

  The hydrogen tank 110 stores hydrogen gas at a high pressure (for example, 87.5 MPa [abs] at the time of filling). The hydrogen tank 110 includes a valve assembly 111 at the end. The hydrogen tank 110 is connected to the first hydrogen supply pipe 121 and the hydrogen filling pipe 140 via the valve assembly 111.

  The first hydrogen supply pipe 121 forms a flow path connecting the hydrogen tank 110 and the supply side manifold 135. The second hydrogen supply pipe 122 forms a flow path connecting the supply side manifold 135 and the regulator 130. The third hydrogen supply pipe 123 forms a flow path that connects the regulator 130 and the fuel cell 100.

  The hydrogen stored in the hydrogen tank 110 is decompressed by the valve assembly 111, further decompressed by the regulator 130, and then supplied to the fuel cell 100. The regulator 130 may be fixed to a floor panel (not shown) of the vehicle, or may be fixed to a tank band (not shown) that fixes the hydrogen tank 110.

  The hydrogen filling pipe 140 is disposed between the hydrogen tank 110 and the filling side manifold 150 and between the filling side manifold 150 and a receptacle (not shown). The receptacle is connected to a nozzle extending from a hydrogen supply device installed in a hydrogen station or the like when the hydrogen tank 110 is filled with hydrogen. Hydrogen supplied from the hydrogen supply device of the hydrogen station is filled into each hydrogen tank 110 from the receptacle through the filling side manifold 150.

  The exhaust drainage pipe 160 is a pipe for draining exhaust gas including the exhaust gas from the fuel cell 100 and generated water to the outside. The exhaust drainage pipe 160 has one end connected to the fuel cell 100 and the other end open to the outside near the rear end of the vehicle. The opening is directed downward by a predetermined angle. The exhaust drainage pipe 160 includes a silencer 161 in the middle of the pipeline.

  As shown in FIG. 1, since the hydrogen tank 110 is mounted so that the valve assembly 111 faces left, the second hydrogen supply pipe 122, the third hydrogen supply pipe 123, and the exhaust drainage pipe 160 are connected to each other. Including the entire piping, it is arranged close to the left side of the vehicle.

As shown in FIG. 1, the fuel cell system 10 includes a connecting pipe 200. The connection pipe 200 is a pipe that connects the exhaust drainage pipe 160 and the safety valve 300 (see FIG. 3) installed under the regulator 130.

  FIG. 2 is a perspective view of the vicinity of the connecting pipe 200. The exhaust drainage pipe 160 is arranged on the lower left side of the regulator 130. The left side of the regulator 130 means the outside of the vehicle.

  The connecting pipe 200 is virtually divided into a first part 201, a second part 202, a third part 203, and a fourth part 204. The first part 201 is a part connected to the safety valve 300 at the upper end and extending downward from the upper end. The second part 202 is connected to the lower end of the first part 201 at the right end and extends from the right end to the left. The third portion 203 is a portion that is connected to the left end of the second portion 202 at the front end and extends rearward from the front end. The fourth part is a part that is connected to the rear end of the third part 203 at the upper end, extends downward from the upper end, and is connected to the exhaust drainage pipe 160 at the lower end. This shape can be obtained by inserting a thermoplastic elastomer hose formed in a cylindrical shape into a mold and applying heating and cooling.

  The connection part between the fourth part 204 and the exhaust drainage pipe 160 does not include a valve or the like and is always open. On the other hand, a safety valve 300 is provided at a connection portion between the first portion 201 and the regulator 130.

  FIG. 3 shows the first portion 201, the cross section of the clip 210 and the safety valve 300, and the regulator 130. The safety valve 300 includes a housing 310, a valve body 320, and a spring 330.

  The casing 310 is fixed to the regulator 130 and forms a flow path from the second hydrogen supply pipe 122 to the outside. The opening of this channel faces downward. The spring 330 is installed in the housing 310, and when the pressure in the second hydrogen supply pipe 122 (hereinafter referred to as “gas pressure”) is less than a first reference value (for example, 3 MPa [abs]), the spring 130 side The valve body 320 is pressed against the valve seat provided in the. The valve body 320 thus pressed blocks the flow path between the second hydrogen supply pipe 122 and the first portion 201. More precisely, the condition for blocking the flow path is when the difference between the gas pressure and the pressure in the first portion 201 is less than the first reference value. However, since the pressure in the first portion 201 is about the same as the pressure in the exhaust / drain pipe 160 and is a small value with respect to the first reference value, it will be described as being zero in the present embodiment.

  The first reference value is set between a gas pressure value at normal times and a gas pressure value that is preferably reduced. The normal gas pressure is a gas pressure during normal operation of the fuel cell system 10 or immediately after the fuel cell system 10 is stopped. The value of the gas pressure that is preferably reduced is a pressure value (for example, 10 MPa [abs]) that can hinder the operation of the regulator 130 and an injector (not shown) provided in the third hydrogen supply pipe 123. The cause of such gas pressure is a leak that occurs when the fuel cell system 10 is suspended for a long period of time. The leak here means that the hydrogen in the hydrogen tank 110 passes through the sealing by the valve assembly 111 and leaks to the first hydrogen supply pipe 121.

  When the gas pressure reaches or exceeds the first reference value, the spring 330 is contracted, the valve body 320 is lowered, and the flow path is opened. When the flow path is opened, hydrogen flows into the first portion 201 from the second hydrogen supply pipe 122. The hydrogen that has flowed into the first portion 201 passes through the connection pipe 200 and flows into the exhaust drainage pipe 160. The hydrogen flowing into the exhaust / drain pipe 160 is diluted by the air in the exhaust / drain pipe 160 and discharged from the vicinity of the rear end of the vehicle to the atmosphere. This discharge is performed along the direction of the opening of the exhaust / drain pipe 160 because it faces slightly downward. If hydrogen is discharged downward, it is safer for the vehicle behind.

  By controlling the opening / closing of the safety valve 300 in this manner, hydrogen is not allowed to flow out from the connection pipe 200 to the exhaust / drainage pipe 160 under normal conditions, but when the gas pressure reaches the first reference value, the second hydrogen By discharging the hydrogen in the supply pipe 122 to the atmosphere, the gas pressure can be controlled so as not to become too high.

  As shown in FIG. 3, the first portion 201 is fixed to the housing 310 by tightening the clip 210. By this fixing, the space between the first portion and the housing 310 is sealed. When the pressure in the first part 201 reaches a second reference value (for example, 15 MPa [abs]), the tightening force of the clip 210 or the first part so that the seal between the first part 201 and the housing 310 is broken. The diameter of 201 is set. If the seal is broken, the clip 210 is detached from the first part, and the first part 201 is detached from the housing 310.

  FIG. 4 shows a state in which the connecting pipe 200 is detached from the safety valve 300 (a state in which the first portion 201 is detached from the housing 310). When the connecting pipe 200 is disconnected from the safety valve 300, hydrogen in the second hydrogen supply pipe 122 is discharged from the safety valve 300 to the atmosphere until the safety valve 300 is closed (until the gas pressure falls below the first reference value).

  The second reference value is set between the first reference value and a gas pressure value (for example, 20 to 70 MPa [abs]) that may cause a failure. This failure is, for example, damage of expensive parts such as a fuel cell stack due to high-pressure hydrogen. Such a pressure may be generated due to a failure of the valve assembly 111, exposure of the hydrogen tank 110 to a high temperature, or the like.

  The discharge from the safety valve 300 is performed downward because the opening of the safety valve 300 faces downward. The downwardly discharged hydrogen is sprayed to the ground because the exhaust drainage pipe 160 is offset to the left (outside of the vehicle) with respect to the safety valve 300 and there are almost no obstacles directly under the safety valve 300. . Since the exhaust drainage pipe 160 is disposed outside the safety valve 300, the hydrogen sprayed on the ground is prevented from diffusing vigorously toward the left side of the vehicle.

  As shown in FIG. 4, a hydrogen sensor 400 is installed near the regulator 130. The hydrogen sensor 400 detects surrounding hydrogen. When this detection is performed, it is assumed that the connecting pipe 200 is disconnected and hydrogen is discharged from the safety valve 300, and the control device (not shown) closes the valve assembly 111. By closing the valve, the amount of hydrogen in the hydrogen tank 110 discharged to the atmosphere can be reduced.

  According to this embodiment, at least the following effects can be obtained. Depending on the value of the gas pressure, hydrogen can be discharged to the atmosphere in a more preferred manner. Specifically, as described above, when the gas pressure value exceeds the first reference value, the exhaust drainage pipe 160 is used to dilute the hydrogen from the vicinity of the rear end of the vehicle. When the gas pressure is discharged rearward and the gas pressure value exceeds the second reference value, hydrogen is discharged downward from the vicinity of the center of the vehicle. Thus, when the gas pressure value reaches or exceeds the second reference value, it is possible to prevent the high-concentration hydrogen in the flow having linearity from being discharged to the rear of the vehicle.

  When the value of the gas pressure reaches the second reference value or more, it is preferable to detect the situation and close the valve assembly 111 as in this embodiment. However, when exhausting backward from the vicinity of the rear end of the vehicle as in the prior art, the detected hydrogen may be readily diffused, and detection may be delayed. On the other hand, in the present embodiment, when the gas pressure value reaches the second reference value or more, it is discharged under the floor, so it was discharged as compared with the case of discharging from the vicinity of the rear end toward the rear of the vehicle. Hydrogen diffusion is slow and detection is likely to be faster.

  The shape of the connecting pipe 200 reduces the possibility that the operation of the safety valve 300 is hindered by freezing. Since the fourth portion 204 is connected to the upper side of the exhaust / drainage pipe 160, water (water droplets, water vapor) existing in the exhaust / drainage pipe 160 hardly enters the connection pipe 200. Furthermore, since there are three bends in the entire connecting pipe 200 and the first part 201 extends upward with respect to the second part 202, even if water enters the fourth part 204, it reaches the safety valve 300. Unlikely.

  In addition, since the entire connection pipe 200 extends rearward (downstream of the exhaust drainage pipe 160) and downward with respect to the safety valve 300, even if water enters the connection pipe 200, it flows out to the exhaust drainage pipe 160. Cheap. Originally, the hydrogen pipe (the second hydrogen supply pipe 122 and the like) is as in this embodiment in order to avoid interference with obstacles (such as stones that are flipped up by running of the vehicle) as much as possible. It is preferable to dispose them above the exhaust drainage pipe 160. It can be said that the shape of the connecting pipe 200 is a reasonable one that matches this arrangement and exhibits the above-described effects.

  The connecting pipe 200 suppresses pulsation in the exhaust / drain pipe 160. This is because the connection pipe 200 functions as a side branch of the exhaust drainage pipe 160 because the connection pipe 200 is always open at the connection site with the exhaust drainage pipe 160.

  The above effects are mainly exhibited by the connecting pipe 200 and the clip 210. The present embodiment is excellent in that a component that exhibits such various effects can be made small, light, and inexpensive.

  The present invention is not limited to the embodiments, examples, and modifications of the present specification, and can be implemented with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in the embodiments described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects described above, replacement or combination can be performed as appropriate. If the technical feature is not described as essential in this specification, it can be deleted as appropriate. For example, the following are mentioned.

When the gas pressure reaches the first reference value or higher and hydrogen is discharged while being diluted, a dedicated pipe provided separately may be used instead of the exhaust drainage pipe. For example, hydrogen may be diluted by flowing an inert gas such as nitrogen through the dedicated pipe.
When the gas pressure reaches or exceeds the second reference value, any structure may be used for removing the connecting pipe at the connecting portion with the safety valve. For example, it may be fixed with an adhesive.
When the gas pressure reaches the second reference value or higher, the connecting pipe does not have to be disconnected at the connection site with the safety valve. For example, it may be disconnected at the connection site with the exhaust drainage pipe or may be damaged at the second site of the connection tube.
Various shapes of the connecting pipe are conceivable. For example, instead of the second part and the third part, a part that linearly connects the first part and the fourth part may be provided.
Any material and manufacturing method may be used for the connecting pipe. For example, it may be made of metal.
The installation site of the safety valve may be provided in a site other than the regulator, for example, the second hydrogen supply pipe.
The structure of the safety valve may be other.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 100 ... Fuel cell 110 ... Hydrogen tank 111 ... Valve assembly 121 ... 1st hydrogen supply piping 122 ... 2nd hydrogen supply piping 123 ... 3rd hydrogen supply piping 130 ... Regulator 135 ... Supply side manifold 140 ... Hydraulic piping 150 ... Filling manifold 160 ... Exhaust drain pipe 161 ... Silent device 200 ... Connection pipe 201 ... First part 202 ... Second part 203 ... Third part 204 ... Fourth part 210 ... Clip 300 ... Safety valve 310 ... Case 320 ... Valve 330 ... Spring 400 ... Hydrogen sensor

Claims (13)

Piping for a fuel cell mounted on a vehicle,
A fuel gas supply pipe for supplying fuel gas to the fuel cell;
When the gas pressure, which is the pressure in the fuel gas supply pipe, reaches or exceeds a first reference value, the gas in the fuel gas supply pipe is discharged from an outlet installed near the rear end of the vehicle, and the gas pressure is A fuel cell pipe comprising: a discharge portion that discharges the gas in the fuel gas supply pipe below the floor of the vehicle and in front of the exhaust port when the second reference value greater than the first reference value is reached . The fuel cell piping according to claim 1,
The discharge part is
A safety valve provided in the fuel gas supply pipe;
An exhaust pipe that includes the exhaust port and discharges fluid other than fuel gas;
A connection pipe that is connected to the exhaust pipe at an exhaust pipe connection site and that is connected to the safety valve to form a connection flow path that connects the safety valve and the exhaust pipe,
When the gas pressure reaches the first reference value or more, the safety valve is operated to discharge fuel gas through the connection pipe and the exhaust pipe,
When the gas pressure reaches or exceeds the second reference value, the connection flow path is damaged by the gas pressure, and thereby the fuel gas is discharged without passing through the exhaust pipe. The fuel cell piping according to claim 2, wherein when the gas pressure reaches the second reference value or more, the connection pipe and the safety valve are disconnected. The fuel cell piping according to claim 3,
A clamping member for fixing the connection pipe to the safety valve by applying a tightening force to the connection pipe;
The fixing by the tightening member is released by the force received through the connection pipe when the gas pressure reaches the second reference value or more. The fuel cell pipe according to any one of claims 2 to 4, wherein the safety valve is disposed above the exhaust pipe connection portion. The fuel cell pipe according to claim 5, wherein the safety valve has an opening facing downward. The fuel cell pipe according to claim 6, wherein the safety valve is disposed closer to the center in the left-right direction than the exhaust pipe connection portion. The fuel cell pipe according to any one of claims 2 to 7, wherein the safety valve is disposed on an upstream side of the exhaust pipe with respect to the exhaust pipe connection portion. The fuel cell pipe according to any one of claims 2 to 8, wherein the connection pipe forms a bent flow path. The fuel cell piping according to any one of claims 2 to 9, wherein the exhaust pipe connection portion is opened when fluid other than the fuel gas is discharged from the exhaust pipe. 11. The fuel cell pipe according to claim 1, further comprising: a detection unit configured to detect that fuel gas is discharged in front of the vehicle and below the floor of the vehicle from the discharge port. A method of discharging fuel gas from a fuel cell system mounted on a vehicle,
When the pressure of the fuel gas reaches the first reference value or more, the fuel gas is discharged from an exhaust port installed near the rear end of the vehicle, and the second reference is larger than the first reference value. A fuel gas discharging method for discharging the fuel gas below the floor of the vehicle and in front of the vehicle from the discharge port when the value is reached. A connecting pipe that connects a safety valve provided in a fuel gas supply pipe for supplying fuel gas to a fuel cell mounted on a vehicle and an exhaust pipe for discharging a fluid other than fuel gas from behind the safety valve. Because
A connection pipe that disconnects at least one of the safety valve and the exhaust pipe when the pressure of the gas in the fuel gas supply pipe reaches a second reference value that is larger than a first reference value that is an operating pressure of the safety valve. .

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