JP2005222723A - Gas fuel dilution structure of fuel cell vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely dilute hydrogen gas leaking from a fuel cell and to surely detect the concentration of the leaking hydrogen gas. <P>SOLUTION: The fuel cell 5 stored in a vessel 3 and a fuel tank 9 supported on a tank frame 11 formed of a hollow pipe material on the rear side of a vehicle are respectively arranged in a lower part of a vehicle floor 1. The hydrogen gas having leaked from the fuel cell 5 is exhausted from a gas exhaust port 3a of the vessel 3; and the exhausted hydrogen is introduced into the tank frame 11 through a gas dilution unit 15 along with outside air and discharged to the outside of the tank frame 11 from a gas discharge port formed in the tank frame 11. A hydrogen concentration sensor is installed on the downstream side of the gas dilution unit 15 to detect the hydrogen concentration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gaseous fuel dilution structure for a fuel cell vehicle that dilutes gaseous fuel leaking from a fuel cell mounted on the vehicle.

  Conventionally, there is a vehicle described in Patent Document 1 as a vehicle equipped with a fuel cell, but there is no disclosure of a specific dilution structure of gas (hydrogen gas) leaking from the fuel cell. However, this fuel cell vehicle has a substantially diluted structure for leaking hydrogen.

That is, this fuel cell vehicle has a fuel cell below the floor, a fuel tank at the rear of the fuel cell and at the lower part of the rear seat, and the fuel tank mounting portion has an upwardly projecting structure. Also, an under cover is installed so as to cover the vehicle side and lower part of the fuel cell, and a hydrogen concentration sensor is provided at the uppermost part inside the bead that protrudes above the floor corresponding to the fuel cell installation part. I am trying to detect hydrogen leaks.
JP 2003-182378 A

  However, in the gas dilution structure of the conventional fuel cell vehicle described above, leaked hydrogen is difficult to flow into the uppermost hydrogen concentration sensor installation portion on the lower surface of the floor and the leaked hydrogen is diluted by the driving wind. Although the under cover is installed, the diluted gas is dispersed by the traveling wind, and the leaked gas cannot be reliably detected.

  Accordingly, an object of the present invention is to reliably dilute the leaked gas from the fuel cell and to reliably detect the leaked gas.

  According to the present invention, a fuel cell housed in a container having an opening and a fuel tank supported by a tank frame having a hollow pipe structure are respectively disposed below a vehicle floor, and the fuel cell is disposed in the vicinity of the opening of the container. The most important thing is to provide a gas diluter for diluting the gaseous fuel leaked from the outside air and introducing it into the tank frame, and to provide a gas concentration sensor for detecting the concentration of the gaseous fuel downstream of the gas diluter. Features.

  According to the present invention, by providing the gas diluter in the vicinity of the opening provided in the container for accommodating the fuel cell, the gaseous fuel leaked from the fuel cell in the container is brought into the tank frame together with the outside air by the gas diluter. Since it is introduced, the gaseous fuel leaked from the fuel cell can be reliably diluted. Further, since the gas concentration sensor is provided downstream of the gas diluter, the concentration of the gaseous fuel introduced into the tank frame can be reliably detected. Furthermore, since the introduced gaseous fuel can be stored in the hollow tank frame to provide a buffer function, the gaseous fuel concentration can be made uniform compared to when the leaked gaseous fuel is directly opened to the atmosphere. Thus, the detection accuracy of the gaseous fuel concentration can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a gaseous fuel dilution structure for a fuel cell vehicle according to a first embodiment of the present invention. In FIG. 1, the left side is the front of the vehicle. In this fuel cell vehicle, a container 3 is fixed to a lower part of a vehicle floor 1 and a fuel cell 5 is accommodated in the container 3. The fuel cell 5 generates electricity by receiving supply of hydrogen and air in a fuel tank 9 described later, and outputs the generated power to a drive motor (not shown) to move the vehicle.

  The vehicle floor 1 behind the above-described fuel cell 5 has a convex portion 1a protruding upward, and a rear seat 7 is installed on the convex portion 1a. A fuel tank 9 for storing hydrogen to be supplied to the fuel cell 5 at a high pressure is disposed below the convex portion 1 a of the vehicle floor 1 on the vehicle rear side of the fuel cell 5. The fuel tank 9 is supported by a tank frame 11 fixed to a vehicle frame member such as a side member (not shown) below the vehicle floor 1.

  2 is a plan view of FIG. 1 with the vehicle floor 1 of FIG. 1 omitted, FIG. 3 is a plan view of a tank frame 11 with the fuel tank 9 of FIG. 2 omitted, and FIG. 4 is a perspective view of the tank frame 11. is there. The tank frame 11 includes front, rear, and front and rear frames 11a and 11b, bottom left and right frames 11c and 11d, which support the front, rear, left and right sides of the substantially cylindrical fuel tank 9, and fuel. Front, rear, and left and right trunk front, rear frames 11e and 11f, trunk left and right frames 11g and 11h, and left and right sides of the trunk rear frame 11f. A rear extension frame 11i, which is a mounting frame that is connected to the rearwardly inclined upward direction, a connecting frame 11j that connects the upper ends of the left and right rear extension frames 11i, 11i, a trunk front frame 11e, and a bottom front frame 11a, a bottom rear frame 11b, and a trunk rear frame 11f, a pair of left and right substantially semicircular shapes that hold the substantially lower half of the fuel tank 9 A fixed frame 11m, are respectively provided.

  Gusset frames 11k are connected to the front side portions of the left and right body frames 11g and 11h and the left and right side portions of the front body frame 11e in a diagonal manner. A front extension frame 11p is formed on the connecting portion of the front ends of the left and right frames 11g and 11h to the gusset frame 11k so as to protrude outward in the vehicle width direction and obliquely upward on the front side of the vehicle. A front extension frame 11q is formed to protrude obliquely upward on the outer side in the vehicle width direction at a connecting portion of the left and right end portions of the front frame 11e to the gusset frame 11k.

  The bottom left and right frames 11c and 11d have their front ends connected to the gusset frame 11k, and the rear ends are connected to a continuous portion of the body rear frame 11f and the body left and right frames 11g and 11h. is there.

  The above-mentioned front and rear frames 11a and 11b and the bottom left and right frames 11c and 11d constitute the bottom frame, while the front and rear frames 11e and 11f, the left and right frames 11g and 11h, and the gusset frame 11k. Constitutes the upper frame.

  Each of the frames 11a to 11k, 11p, and 11q is formed of a metal pipe material, and the hollow pipe structures are connected to each other.

  In addition, front and rear mounting brackets 7 and 9 made of metal blocks are provided on the connecting portion between the front extension frames 11p and 11q and on the left and right sides of the connecting frame 11j, respectively. The front and rear mounting brackets 7 and 9 are fixed at predetermined positions below the vehicle floor.

  On the other hand, the substantially semicircular fixed frame 11m is a plate material on which the fuel tank 9 is placed and supports the outer periphery of the bottom, and the placement surface of the fuel tank 9 is formed into a concave curved surface.

  The fuel tank 9 is placed on the fixed frame 11m and covered with a pair of left and right substantially semicircular binding belts 13 from above, and the front and rear of the fixing frame 11m and the binding belt 13 are covered. The fixing portions 11 mA and 13 A provided at the end portions are fastened with bolts and nuts, and the fuel tank 9 is fixed to the tank frame 11.

  Each of the fixed frame 11m and the binding belt 13 is configured as a rigid body made of a metal band plate material, and an inner surface that contacts the outer peripheral surface of the fuel tank 9 includes a cushion portion made of an elastic material such as rubber or resin. Yes.

  A gas diluter 15 is provided on the side of the tank frame 11 on the left side in the vehicle width direction (lower side in FIGS. 2 and 3) on the side facing the container 3 of the body front frame 11 e in the vicinity of the fixing portions 11 mA and 13 A. is there.

  A gas discharge port 3a as an opening is provided on the vehicle rear side of the container 3 facing the gas diluter 15 described above. The gas discharge port 3a discharges hydrogen gas, which is gaseous fuel leaked from the fuel cell 5 in the container 3, to the outside. Outside air is discharged into the container 3 at a symmetrical position in the vehicle width direction with respect to the gas discharge port 3a, that is, at a position corresponding to the fixing portions 11mA, 13A on the right side in the vehicle width direction (upper side in FIGS. An outside air inlet 3b to be introduced is provided.

  The gas diluter 15 dilutes the hydrogen gas flowing out from the gas discharge port 3a with the outside air, and includes a duct 17 and a fan 19 disposed in the duct 17. A notch 17d for avoiding interference with the fixing portion 11mA of the tank frame 11 and the fixing portion 13A of the binding belt 13 is provided on the vehicle rear side in the center of the duct 17 in the vehicle width direction.

  FIG. 5 is an enlarged cross-sectional view around the gas diluter 15, and the duct 17 has a gas introduction port 17 a on the vehicle front side facing the gas discharge port 3 a of the container 3. The gas inlet 17a has a larger opening area facing each other than the gas outlet 3a to facilitate introduction of the outside air A. The duct inner surface 17b downstream of the fan 19 behind the gas introduction port 17a is an inclined surface for guiding gas. The duct inner surface 17b serving as the inclined surface is inclined so that the lower part is positioned rearward of the vehicle body from the upper part, and the lower end part is connected to the upper part of the trunk front frame 11e.

  On the other hand, the vehicle rear end portion of the bottom wall 17c of the duct 17 is connected to the upper portion of the trunk front frame 11e, and a communication hole 21 for communicating the duct 17 and the inside of the trunk front frame 11e is provided at this connection portion. A gas concentration sensor 23 for detecting the concentration of hydrogen gas leaked from the fuel cell 5 is provided at the end of the communication hole 21 on the vehicle rear side and at the lower end of the duct inner surface 17b, that is, downstream of the inclined surface.

  As shown in FIG. 3, the diluted gaseous fuel introduced into the tank frame 11 is discharged to the outside of the tank frame 11 in the front and rear frames 11 a and 11 b and the left and right frames 11 c and 11 d of the bottom of the tank frame 11. Gas discharge ports 25 and 27 are provided.

  For example, five gas discharge ports 25 of the bottom front and rear frames 11a and 11b are provided and set at positions where they face each other. On the other hand, for example, two gas discharge ports 27 of the bottom left and right frames 11c and 11d are provided and set at positions where they face each other.

  Next, the operation will be described. The hydrogen gas leaked into the container 3 from the fuel cell 5 is driven into the duct 17 from the container 3 through the gas discharge port 3a as the outside air is introduced from the outside air introduction port 3b by driving the fan 19 of the gas diluter 15. Inflow. At this time, as shown in FIG. 5, since the outside air A also flows into the duct 17 together with the leaked hydrogen gas H, both of them mix to reliably dilute the hydrogen gas H.

  When diluted by the outside air A, the leaked hydrogen gas H is guided downward by the inclined duct inner surface 17b downstream of the fan 19, and the hydrogen concentration is reliably detected by the gas concentration sensor 23 provided at the lower portion.

  The diluted hydrogen gas in the duct 17 flows into the body front frame 11e of the tank frame 11 through the communication hole 21, and then flows through each part of the tank frame 11 having a communication structure with each other. The gas discharge ports 25 and 27 shown are dispersed and discharged to the outside of the tank frame 11. Thereby, hydrogen concentration when hydrogen gas is opened to the atmosphere can be reduced.

  At this time, since the introduced gas is stored in the hollow tank frame 11, a buffer function can be provided, so that the gas concentration can be made uniform as compared with the case where the leaked hydrogen gas is directly opened to the atmosphere. It becomes possible, and the detection accuracy of the gas concentration by the gas concentration sensor 23 can be improved.

  Further, the gas discharge ports 25 of the bottom front and rear frames 11a and 11b are set at positions facing each other, while the gas discharge ports 27 of the bottom left and right frames 11c and 11d are also positioned at positions facing each other. Therefore, the released gas can avoid direct release to the outside of the vehicle, and even when the release energy (flow velocity, pressure) is large, the released jets collide with each other and both kinetic energy The momentum can be offset.

  When the gas discharge port 25 is provided in the front and rear frames 11e and 11f and the gas discharge port 27 is provided in the left and right frames 11g and 11h, the discharged gas is applied to the fuel tank 9. Emission energy can be suppressed.

  Further, since the gas diluter 15 is disposed between the container 3 and the tank frame 11, the dead space between them can be used effectively.

  FIG. 6 is a plan view corresponding to FIG. 3, showing a second embodiment of the present invention. In this embodiment, one gas discharge port 25 is provided at a position in the center of the bottom front frame 11a in the vehicle width direction and opposed to the bottom rear frame 11b, and a gas concentration sensor 23 is installed in the one gas discharge port 25. doing.

  In this embodiment, at least one flow path in which the gas flows in one direction from the gas diluter 15 to the gas discharge port 25 is provided inside the tank frame 11, and the gas flow path in the tank frame 11 is made as long as possible. It is comprised so that it may become. That is, the gas flowing into the gas diluter 15 flows from the trunk front frame 11e toward the left side (lower side in FIG. 6) gusset frame 11k as indicated by an arrow in FIG. Frame 11g → trunk rear frame 11f → trunk right frame 11h → right side (upper side in FIG. 6) gusset frame 11k → bottom right frame 11d → bottom rear frame 11b → bottom left frame 11c and then flow into the bottom front frame 11a. Then, it is discharged from the gas discharge port 25 to the outside of the tank frame. At the time of this release, the gas concentration sensor 23 detects the hydrogen concentration.

  According to the second embodiment described above, the gas discharge port 5 is integrated into one, and the gas concentration sensor 23 is provided in the single gas discharge port 5, so that diluted gaseous fuel (immediately before being discharged outside the tank frame). The gas concentration sensor 23 always comes into contact with the gas concentration sensor 23 when it is released, so that the hydrogen gas concentration can be reliably detected.

  In addition, since the gas discharge port 25 is opened on the side opposite to the vehicle traveling direction, the backflow of gas into the tank frame 11 due to traveling wind can be prevented.

  Further, by making the flow path in the tank frame from the gas diluter 15 to the gas discharge port 25 as long as possible, the gas discharge energy (flow velocity, pressure) can be suppressed.

  According to the present invention, since a plurality of gas discharge ports for discharging the diluted gas to the outside of the tank frame are provided, the gas flowing into the tank frame can be dispersed and discharged, and the gas fuel concentration when released to the atmosphere is reduced. This can be further reduced. Moreover, the direct discharge | release of the gas to the vehicle exterior can be prevented by making a some gas discharge port mutually oppose. Furthermore, even when the energy released from the gas outlet (flow velocity, pressure) is large, the jets of the released gas can collide directly, and the momentum of both can be offset by the kinetic energy of the jets.

  By disposing the gas concentration sensor in the gas discharge port provided in one tank frame, it is possible to accurately detect the diluted gaseous fuel (the gas immediately before being released to the outside of the tank frame), and when discharging Since it is always in contact with the gas concentration sensor, the gas concentration can be reliably detected.

  Since at least one flow path in which gas fuel flows in one direction from the gas diluter to the gas discharge port is provided inside the tank frame, the gas flow path from the gas diluter to the gas discharge port can be set long. The gas release energy (flow velocity, pressure) can be suppressed.

  Since the gas diluter is composed of a duct and a fan arranged in the duct, the duct inner surface downstream of the fan is an inclined surface for guiding gaseous fuel, and a gas concentration sensor is provided on the downstream side of the inclined surface. The gaseous fuel that has flowed into the gas diluter can reliably contact the gas concentration sensor along the inclined surface and reliably detect the gas concentration.

  Since the tank frame is disposed on the vehicle rear side of the container and the gas diluter is provided between the opening provided on the vehicle rear side of the container and the tank frame, the gas diluter is installed. In addition, the dead space between the container and the tank frame can be used effectively.

It is a side view which shows the gaseous fuel dilution structure of the fuel cell vehicle concerning the 1st Embodiment of this invention. It is the top view which abbreviate | omitted the vehicle floor of FIG. It is a top view of the tank frame which abbreviate | omitted the fuel tank of FIG. It is a perspective view of a tank frame. It is sectional drawing to which the gas dilution device periphery was expanded. It is a top view equivalent to FIG. 3 which shows the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle floor 3 Container which accommodates a fuel cell 3a Gas exhaust port (opening part)
5 Fuel Cell 9 Fuel Tank 11 Tank Frame 15 Gas Diluter 17 Gas Diluter Duct 17b Duct Inner Surface (Inclined Surface)
19 Gas dilution fan 23 Gas concentration sensor 25, 27 Gas outlet

Claims (6)

  A fuel cell housed in a container having an opening and a fuel tank supported by a tank frame having a hollow pipe structure are respectively disposed below the vehicle floor, and gas leaked from the fuel cell is disposed in the vicinity of the opening of the container. A fuel cell vehicle characterized in that a gas diluter for diluting fuel with outside air and introducing it into the tank frame is provided, and a gas concentration sensor for detecting the concentration of the gaseous fuel is provided downstream of the gas diluter. Gas fuel dilution structure.   2. The gas discharge port according to claim 1, wherein a plurality of gas discharge ports for discharging the gaseous fuel introduced into the tank frame to the outside of the tank frame are provided in inner portions of the tank frame facing each other. Gas fuel dilution structure for a fuel cell vehicle.   2. The gas concentration sensor according to claim 1, wherein one gas discharge port for discharging the gaseous fuel introduced into the tank frame to the outside of the tank frame is provided, and the gas concentration sensor is provided at the one gas discharge port. Gas fuel dilution structure for a fuel cell vehicle.   4. The gaseous fuel of a fuel cell vehicle according to claim 3, wherein at least one flow path in which the gaseous fuel flows in one direction from the gas diluter to the gas discharge port is provided in the tank frame. Dilution structure.   The gas diluter is composed of a duct and a fan disposed in the duct, and the duct inner surface downstream of the fan is an inclined surface for guiding the gaseous fuel, and the gas concentration sensor is disposed downstream of the inclined surface. The gaseous fuel dilution structure for a fuel cell vehicle according to claim 1 or 2, wherein the structure is provided.   The tank frame is arranged on the vehicle rear side of the container, and the gas diluter is provided between the tank frame and the opening provided on the vehicle rear side of the container. The gaseous fuel dilution structure for a fuel cell vehicle according to any one of claims 5 to 6.

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