JP2007055405A - Vehicle mounting structure of fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To install a heat-insulating material of an optimum shape under a floor of a vehicle without especially securing an area for installing the heat-insulating material or specially providing a fixing point of the heat-insulating material. <P>SOLUTION: In this vehicle mounting structure of a fuel cell system, a fuel cell system 1 is arranged below a floor panel 11 of a vehicle, and a heat-insulating material 100 for heat-insulating and protecting the fuel cell system 1 is arranged between the floor panel and the fuel cell system. The heat-insulating material 100 is made of a soft material such as urethane, rubber, and polystyrene foam, and nipped by the floor panel 11 and the fuel cell system 1. Also, communication holes as ventilation holes are formed on the heat-insulating material 100, and the inside of a closed space surrounding the fuel cell system 1 is ventilated through the communication holes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-vehicle structure of a fuel cell system including a hydrogen system (fuel supply / exhaust system), an air system (air supply / exhaust system), a cooling system, and the like centering on a fuel cell.

  In the in-vehicle fuel cell system, freezing of the generated water and condensed water in the system when the vehicle is left in a low temperature environment such as in winter will cause the startup time to be extended the next time the system is started. It is a problem that must be done.

  Generally, as a method for solving the problem, a heat insulating material is provided around a fuel cell system (a unit having a fuel supply / exhaust system, an air supply / exhaust system, a cooling system, etc. around the fuel cell) to freeze the fuel cell system. There are known a method of delaying and a method of thawing by a heating means such as an electric heater.

Further, as described in Patent Document 1, the fuel cell system is accommodated in a heat insulation box, and heat from another heat source (heat exchanger of the air conditioner) is introduced into the heat insulation box, thereby the fuel cell. A method of warming up and thawing the system is also considered.
JP 2004-241303 A

  However, if the fuel cell system is insulated and protected by using a hard heat insulating material such as a vacuum heat insulating material, for example, a part of the fuel cell system mounting space determined by the vehicle size will be occupied by the heat insulating material. Become. Furthermore, since it is necessary to provide a fixing point for the heat insulating material, there is a problem that the space in which the fuel cell system can be mounted is reduced and the degree of freedom in layout is reduced. In general, when the fuel cell system is placed under the floor panel of a vehicle, the floor panel has a complicated shape from the viewpoint of reinforcement, safety in the cabin, comfortability, etc. It is difficult to arrange the heat insulating material in a simple shape.

  In consideration of the above circumstances, the present invention does not secure a special region for installing the heat insulating material, and does not provide a special fixing point for the heat insulating material and installs the heat insulating material in an optimal shape under the vehicle floor. It is an object of the present invention to provide an on-vehicle structure of a fuel cell system that can be used.

  The present invention provides a fuel cell system in which a fuel cell system is disposed below a floor panel of a vehicle, and a heat insulating material for heat-insulating and protecting the fuel cell system is disposed between the floor panel and the fuel cell system. The heat insulating material is made of a soft material and is sandwiched between the floor panel and the fuel cell system.

  According to the present invention, since the heat insulating material disposed between the floor panel and the fuel cell system is sandwiched between the floor panel and the fuel cell system, the vehicle and the vehicle can be provided without specially fixing the heat insulating material. It is possible to insulate the fuel cell system and to prevent the heat of the fuel cell system from being radiated through the vehicle. In addition, since the heat insulating material is made of a soft material, unlike the case where a hard heat insulating material is provided, the heat insulating material is arranged in an optimal shape using a small space between the floor panel and the fuel cell system. can do. Therefore, as in the case of providing a hard heat insulating material, by providing the heat insulating material, the mounting space of the fuel cell system is not violated, and the degree of freedom of the layout of the fuel cell system can be increased.

  Further, according to the present invention, since the heat insulating material is made of a soft material, the heat insulating material can function as a buffer means between the vehicle and the fuel cell system. It is no longer necessary to secure an extra space for preventing interference between them, and a compact layout of the fuel cell system becomes possible.

  The fuel cell system includes a fuel cell as power generation means, a hydrogen system (fuel supply / discharge system) that supplies and discharges hydrogen as fuel to the fuel cell, and air that supplies air as an oxidant to the fuel cell. System (air supply / exhaust system) as the main components. By supplying hydrogen from the hydrogen system and air from the air system to the fuel cell, the fuel cell uses these hydrogen and oxygen in the air. Is generated electrochemically to obtain generated power.

  In a fuel cell, a fuel cell (anode) to which hydrogen is supplied and an oxidant electrode (cathode) to which air is supplied are stacked with an electrolyte / electrocatalyst composite interposed therebetween, and a power generation cell is formed. It has a structure in which power generation cells are stacked in multiple stages. In particular, in the fuel cell system 1 of the present embodiment, a solid polymer type fuel cell is used as the fuel cell. A solid polymer type fuel cell uses a solid polymer membrane as an electrolyte, and is excellent in terms of high energy density, low cost, light weight, and the like. The solid polymer electrolyte membrane is made of an ion (proton) conductive polymer membrane such as a fluororesin ion exchange membrane, and functions as an ion conductive electrolyte when saturated with water.

  The hydrogen system includes, for example, a high-pressure hydrogen tank that stores hydrogen, a hydrogen supply passage, a variable valve, a hydrogen exhaust passage, a humidifier, a waste hydrogen treatment device, and the like. In this hydrogen system, hydrogen taken out from a high-pressure hydrogen tank as a hydrogen supply source is supplied to the fuel electrode of the fuel cell through the hydrogen supply passage after the flow rate and pressure are adjusted by a variable valve or the like. The anode exhaust gas discharged from the fuel electrode of the fuel cell is discharged outside the system after the hydrogen concentration is sufficiently diluted by the exhaust hydrogen treatment device through the hydrogen exhaust passage.

  The configuration of the hydrogen system is not limited to the above example, and any conventionally known configuration can be adopted. For example, a hydrogen circulation type configuration may be employed in which surplus hydrogen that has not been consumed by power generation in the fuel cell is circulated using a pump or ejector and supplied to the fuel electrode of the fuel cell again. Makes it possible to efficiently generate power in the fuel cell while increasing the utilization efficiency of hydrogen.

  In order to generate power with a fuel cell, it is necessary to supply hydrogen as a fuel and air as an oxidant, and the fuel cell system is provided with an air system as a mechanism for that purpose.

  The air system includes, for example, a compressor that compresses air and supplies the fuel cell, an air cooling device, an air supply passage, a humidifier, an air exhaust passage, and a variable valve. In this air system, the air supplied by compressing the atmosphere with a compressor is adjusted in flow rate and pressure by a variable valve, etc., adjusted to an appropriate temperature and humidity by an air cooling device or humidifier, and the fuel cell. Supplied to the oxidizer electrode. Further, the exhaust gas discharged from the oxidant electrode of the fuel cell is discharged outside the system through the air exhaust passage.

  In addition, in order to generate power with the fuel cell, it is necessary to cool, and the fuel cell system is provided with a cooling system as a mechanism for that purpose.

  For example, the cooling system circulates cooling water obtained by mixing ethylene glycol and water through a pump, a heat dissipation device, a filter, or the like. The cooling system can also be used as a cooling means for a device that generates heat, such as a hydrogen pump or an air compressor, other than the fuel cell.

  Further, for example, various valves and pumps of the hydrogen system, the air system, and the cooling system operate with a coil, a motor, and the like, and thus have an arbitrary harness. Further, there may be a harness that transmits high-voltage power generated in the fuel cell.

  The hydrogen system, air system, cooling system, harness and other devices necessary for the operation of the fuel cell described so far are called auxiliary equipment, and the fuel cell main body and the auxiliary equipment are collectively called a fuel cell system. The present invention is applied to a vehicle equipped with a fuel cell system under the vehicle floor. However, various configurations of the fuel cell system are conceivable, and the present invention is applicable to all of them.

  By the way, the fuel cell oxidizes the hydrogen supplied from the hydrogen system with the air supplied from the air system, and takes out the electric power generated at this time by the load. Therefore, as a result of this reaction, a large amount of water (produced water) is produced, and this produced water is discharged out of the system through the hydrogen exhaust passage and the air exhaust passage.

  However, it is difficult to completely discharge all water, such as water remaining in the valve, due to surface tension. Further, when the system temperature is lowered after the system is stopped, condensed water is generated in addition to the generated water and remains in the system.

  It is desired that the vehicle is quickly started without any trouble even after the vehicle is left in a sub-freezing atmosphere in winter. However, when the generated water or condensed water is frozen in a sub-freezing atmosphere, it can be considered that hindering a desired quick start-up may occur due to, for example, sticking of a valve or blockage of a flow path.

  As this countermeasure, it is conceivable to cover the fuel cell system with a heat insulating material. The present invention provides a method of arranging the heat insulating material.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

  In FIG. 1, 1 is a fuel cell system, 2 is a system subframe (member that supports the fuel cell system), 3 is an under cover (member that protects the fuel cell system), 11 is a floor panel of the vehicle body, and 12 is a vehicle body member. , 100 indicates a heat insulating material. Here, the heat insulating material 100 is formed of a soft material such as urethane, rubber, or polystyrene foam.

  The fuel cell system 1 is fastened to the system subframe 2 and is fixed to the vehicle from below the vehicle via a vehicle body member 12. An under cover 3 is attached to the lower part of the system subframe 2.

  The heat insulating material 100 made of a soft material is disposed between the fuel cell system 1 and the floor panel 11 and is fixed by being sandwiched between the fuel cell system 1 and the floor panel 11. And the vehicle body are thermally insulated by a heat insulating material 100. For this reason, it is possible to minimize the heat of the fuel cell system 1 being radiated through a vehicle body made of a material having good heat conduction and heat transfer, such as iron or aluminum.

  In addition, since the heat insulating material 100 is made of a soft material, unlike the case where a hard heat insulating material is provided, the space between the floor panel 11 and the fuel cell system 1 is utilized to insulate with an optimal shape. A material 100 can be disposed. Therefore, as in the case where a hard heat insulating material is provided, by providing the heat insulating material, a part of the mounting space of the fuel cell system 1 is not occupied, and the degree of freedom of layout of the fuel cell system 1 is increased. be able to.

  Furthermore, normally, a predetermined space is provided between the fuel cell system 1 and the floor panel 11 in order to prevent the fuel cell system 1 from interfering with the floor panel 11 due to vibration during traveling. Since the heat insulating material 100 made of a soft material interposed between the floor panel 11 functions as a cushioning material, the gap between the fuel cell system 1 and the floor panel 11 can be reduced as much as possible, and the fuel cell system One layout area can be enlarged.

  The heat insulating material 100 is positioned by the uneven shape of the floor panel 11 and the uneven shape of the fuel cell system 1. That is, generally, the lower surface side of the floor panel 11 has an arbitrary uneven shape, and the upper surface side of the fuel cell system 1 also has an arbitrary uneven shape. Therefore, the heat insulating material 100 is positioned by meshing with these uneven shapes.

  By positioning in this way, the heat insulating material 100 can be reliably fixed without providing a special fixing point, and the heat insulating material 110 can be moved even when the vehicle is driven by vibration or input from the outside. Can be prevented.

  In addition, the heat insulating material 120 is also arranged on the lower side and the side of the fuel cell system 1 similarly to the heat insulating material 100 above, and the heat insulating material 120 is connected to the fuel cell system 1 and the system subframe 2 or the underframe. It is pinched by the cover 3.

  As described above, the heat insulating material 120 is also disposed below and on the side of the fuel cell system 1 and is sandwiched between the fuel cell system 1 and a member that supports or protects the fuel cell system 1. Therefore, the temperature decrease of the fuel cell system 1 due to radiation from the ground or the like can be effectively prevented by the heat insulating material 120. Moreover, since the heat insulating material 120 can be held without providing a special fixing point, it can be easily attached.

  By the way, when the fuel cell system 1 is mounted under the floor, there is no member that supports or protects the heat insulating material 100 on the front side (front side in FIG. 1) of the system subframe 2. That is, the floor panel 11 exists on the upper side, but no member such as the floor panel 11 exists on the front side of the vehicle. Therefore, the position of the heat insulating material 100 may be moved or the leading edge of the heat insulating material 100 may be damaged due to pebbles (chippings) on the road surface rolled up during traveling or water pressure when traveling on a flooded road surface. Conceivable.

  On the other hand, from the front edge of the system subframe 2, for example, piping for flowing cooling water to the heat radiating means and various harnesses extend. Therefore, by providing simple positioning means for these pipes and various harnesses, movement of the heat insulating material 100 due to chipping or water pressure can be prevented.

  FIG. 2 shows an example. In the figure, 100 is a heat insulating material, 21 is piping, 22 is positioning means, and 23 is fastening means such as a hose clamp. The positioning means 22 is attached to the pipe 21 and stopped by the fastening means 23, thereby preventing the heat insulating material 100 from moving by the positioning means 22.

  The positioning means 22 in this case has a sleeve shape having a flange portion 22A as shown in FIG. 3, is made of rubber or resin, and is fixed to the pipe 21 by fastening means 23 such as a hose clamp. In FIG. 3, the fastening means 23 is not shown. Since the heat insulating material 100 is provided with a through-hole having substantially the same size as the penetrating pipe, the flange 22A of the positioning means 22 interferes with the heat insulating material 100, and the heat insulating material 100 is in the direction indicated by the arrow X in FIG. Prevent moving.

  In FIG. 2, the case where the positioning means 22 is provided in the pipe 21 to fix the heat insulating material 100 is shown. However, the same positioning means is provided in a member that penetrates the other heat insulating material 100 such as a harness, and the heat insulating material 100 is provided. May be prevented from moving.

  Thus, since the positioning means 22 of the heat insulating material 100 is provided in the piping 21 or the harness that penetrates the heat insulating material 100, the movement of the heat insulating material 100 can be more strongly suppressed, and traveling wind or a submerged road can be traveling. It is possible to prevent the heat insulating material 100 from being rolled up by water pressure or the like.

  Moreover, as shown in FIG. 4, it is also conceivable to arrange a reinforcing plate 101 made of metal or resin at the front edge of the heat insulating material 100. The reinforcing plate 101 is for increasing the rigidity of the heat insulating material 100, and may be fastened to the heat insulating material 100 with a bolt or the like, or may be attached with an adhesive material or the like. Moreover, the effect is not changed even if the reinforcing plate 101 is provided on either the front or back of the heat insulating material 100. In the figure, the side indicated by A is the side on which the fuel cell system 1 is arranged.

  Thus, when the reinforcement board 101 is arrange | positioned at least at the front edge part of the heat insulating material 100, the damage of the heat insulating material 100 by the chipping at the time of driving | running | working, the water pressure during flooding, etc. can be prevented.

  Further, by providing the heat insulating materials 100 and 120 around the fuel cell system 1, the fuel cell system 1 exists in a closed space surrounded by the heat insulating materials 100 and 120. For this reason, there is a risk that combustible gas including hydrogen gas supplied as fuel accumulates in the closed space. This is not preferable for safety.

  Therefore, as shown in FIG. 1, when the combustible gas detection means 200 for detecting the combustible gas is provided in the closed space, and the combustible gas concentration detected by the combustible gas detection means 200 becomes a predetermined value or more, for example, It is conceivable to take measures such as issuing a warning to the driver. The combustible gas detection means 200 is desirably provided at the highest position of the heat insulating material 100 because hydrogen gas stays at the highest position in the closed space.

  Further, in order to ventilate the closed space, as shown in FIG. 5, it is preferable to open a communication hole 102 in a portion of the heat insulating material 100 in contact with the outside air so as to let the combustible gas escape to the outside air.

  In addition, the presence of the communication hole 102 communicating with the outside air in the heat insulating material 100 is not preferable in terms of heat insulation performance in a low temperature environment. Therefore, the opening / closing means 103 is provided in the communication hole 102 communicating with the outside air, and a predetermined predetermined value is obtained. It is also conceivable to ventilate the closed space by opening and closing the opening / closing means 103 under conditions.

  As the opening / closing means 103, for example, a valve may be provided in the communication hole. Further, a ventilation fan may be provided to forcibly send outside air into the closed space.

  As a condition for opening / closing the opening / closing means 103, for example, the opening / closing means 103 is opened only when the vehicle speed detected by the vehicle speed detecting means is equal to or higher than a predetermined value (for example, when the vehicle is traveling), It is also conceivable to set the opening / closing means 103 to be closed (when the vehicle is stopped).

  Thus, when the communication hole 102 is provided in the heat insulating material 100, the ventilation of the closed space surrounded by the heat insulating material 100 and the air cooling effect of the fuel cell system 1 can be obtained. In particular, when the communication hole 102 can be opened and closed under predetermined conditions, the communication hole 102 can be closed when the system is stopped to improve the heat insulation performance, and the communication hole 102 can be used when the system is operating. By opening, the ventilation performance can be improved.

  Further, when the fuel cell system 1 is surrounded by the heat insulating material 100, it is desirable to provide a drain hole at the bottom of the heat insulating material 100. In such a case, even if water accumulates above the heat insulating material 100 for some reason, it can be drained downward through the drainage hole, preventing corrosion of the heat insulating material 100 and deformation of the heat insulating material 100 due to the mass of stored water. can do.

It is sectional drawing of the vehicle-mounted structure of the fuel cell system in a present Example. It is the principal part expansion perspective view which showed the example which controls the movement of a heat insulating material with a positioning means. It is a side view which shows the principal part of FIG. It is a perspective view which shows the example which provided the reinforcement board in the heat insulating material. It is a principal part expanded sectional view which shows the example which provided the communicating hole and valve | bulb which function as a ventilation hole in a heat insulating material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell system 2 ... System sub-frame (member which supports a fuel cell system)
3. Under cover (member for protecting the fuel cell system)
DESCRIPTION OF SYMBOLS 11 ... Vehicle floor panel 21 ... Piping 22 ... Positioning means 100, 120 ... Heat insulation material 101 ... Reinforcing plate 102 ... Communication hole 103 ... Opening / closing means 200 ... Combustible gas detection means

Claims (9)

An in-vehicle structure of a fuel cell system in which a fuel cell system is disposed below a floor panel of a vehicle, and a heat insulating material is disposed between the floor panel and the fuel cell system to protect and insulate the fuel cell system. There,
An in-vehicle structure of a fuel cell system, wherein the heat insulating material is made of a soft material and is sandwiched between the floor panel and the fuel cell system. An in-vehicle structure of the fuel cell system according to claim 1,
The in-vehicle structure of the fuel cell system, wherein the heat insulating material is positioned by the uneven shape of the floor panel and the uneven shape of the fuel cell system. An in-vehicle structure of the fuel cell system according to claim 1 or 2,
In addition to the heat insulating material disposed between the floor panel and the fuel cell system, heat insulating material is also provided below and on the side of the fuel cell system, and disposed below and on the side of the fuel cell system. An in-vehicle structure for a fuel cell system, wherein the heat insulating material is sandwiched between the fuel cell system and a member that protects or supports the fuel cell system. The on-vehicle structure of the fuel cell system according to any one of claims 1 to 3,
An in-vehicle structure for a fuel cell system, characterized in that positioning means for regulating a position of the heat insulating material is provided in a pipe or a harness that penetrates the heat insulating material. It is a vehicle-mounted structure of the fuel cell system according to any one of claims 1 to 4,
An in-vehicle structure of a fuel cell system, wherein a water drain hole is provided in the heat insulating material. An in-vehicle structure of the fuel cell system according to any one of claims 1 to 5,
An in-vehicle structure of a fuel cell system, wherein the heat insulating material is disposed so as to surround the fuel cell system, and a communication hole communicating with outside air is provided in at least one location of the heat insulating material. An in-vehicle structure of the fuel cell system according to claim 6,
An on-vehicle structure for a fuel cell system, comprising: opening / closing means for opening / closing the communication hole under a predetermined condition. It is a vehicle-mounted structure of the fuel cell system according to any one of claims 1 to 7,
An in-vehicle structure of a fuel cell system, wherein a closed space surrounding the fuel cell system is constituted by the heat insulating material, and a combustible gas detection means is provided in the closed space. The vehicle-mounted structure of the fuel cell system according to any one of claims 1 to 8,
An in-vehicle structure for a fuel cell system, comprising a reinforcing plate for reinforcing the heat insulating material at least at a front edge in the vehicle traveling direction of the heat insulating material.

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