JP4618182B2 - Vehicle fuel gas detection device - Google Patents

Description

  The present invention relates to a vehicular fuel gas detection device that is used in a vehicle equipped with a fuel cell that generates power using a fuel gas such as hydrogen gas and detects leaked fuel gas.

  2. Description of the Related Art There is known a vehicle equipped with a fuel cell that generates electricity using hydrogen gas as a fuel and outputs electricity as a power source. In this type of vehicle, hydrogen gas used as fuel is loaded into a fuel reservoir such as a hydrogen gas tank. Hydrogen gas in the fuel reservoir is supplied to the fuel cell through a predetermined pipe during power generation.

  By the way, hydrogen gas may leak from a pipe or a fuel reservoir. Since hydrogen gas ignites and explodes depending on the conditions, it is desirable to detect the leak as soon as hydrogen gas leaks. Therefore, a vehicle equipped with a fuel cell using a fuel gas such as hydrogen gas is provided with a predetermined fuel gas detector (hydrogen gas sensor) at a location where the fuel gas can leak (see, for example, Patent Document 1).

JP 2004-191164 A

  A fuel reservoir (for example, a hydrogen gas tank) that can be a fuel gas leakage source may be mounted at a location where snow can enter from the outside, such as under the floor of a vehicle. In such a case, since the fuel gas detector (for example, hydrogen gas sensor) is installed in the vicinity of the hydrogen gas tank, it is in a situation where it can be covered with snow entering from the outside. When the hydrogen gas sensor is covered with snow, in some cases, hydrogen gas cannot be detected, which is a problem.

  An object of the present invention is to prevent the fuel gas detector from being unable to detect fuel gas such as leaked hydrogen gas due to being covered with snow.

  A vehicle fuel gas detection device according to the present invention includes a fuel cell system having a fuel cell that generates power using fuel gas, and a fuel gas detector that detects fuel gas leaked from the fuel cell system. In the gas detection device, the fuel gas detector includes a fuel gas collection unit that collects fuel gas, and a snow melting unit that is disposed in the vicinity of the fuel gas collection unit and melts snow. And According to this vehicle fuel gas detection device, the snow melting means can melt snow at least at a portion where the fuel gas is introduced into the fuel gas detector. Therefore, the fuel gas detector can be brought into a state in which leakage of the fuel gas can be detected without melting the entire snow that has entered. In addition, since the amount of heat for melting snow can be kept to a minimum, the fuel consumption can be improved.

  In the above vehicle fuel gas detection device, the fuel gas collecting means is, for example, a recess provided in an upper part of a fuel cell system installation site. If the fuel gas collecting means is a recess, and this recess is provided at the top of the fuel cell system installation site, when a fuel gas lighter than air, such as hydrogen gas, leaks, the leaked fuel gas is removed from the fuel gas collecting means. It can be collected in the recess.

  In the above vehicle fuel gas detection device, the snow melting means is disposed below the fuel gas collecting means and melts at least snow in the recess. According to this vehicle fuel gas detection device, at least snow in the recess of the fuel gas collecting means can be melted. Therefore, it is possible to avoid a state in which the fuel gas detector in the recess of the fuel gas collecting means is covered with snow and cannot detect leaked gas.

  The vehicle fuel gas detection device according to the present invention further comprises a temperature sensor for detecting the temperature of the fuel cell system installation site, and a control unit for starting the snow melting means based on the detected value of the temperature sensor. It is characterized by providing. According to the vehicle fuel gas detection device, the snow melting means can be started based on the detection value of the temperature sensor.

  In the vehicle fuel gas detection device, the snow melting means is, for example, an electric heater. If an electric heater, which is a heating element, is used as a snow melting means, snow can be melted by the heat generated by the electric heater.

  A vehicle fuel gas detection device according to the present invention is a vehicle provided with a fuel gas detector provided on an upper part of an installation site of a fuel cell system having a fuel cell that generates power using fuel gas, and detects leaked fuel gas. In the fuel gas detection apparatus for use, a snow melting means comprising a pipe provided in the fuel cell system and an exhaust gas pipe through which exhaust gas discharged from the fuel cell passes is provided in the installation site. If a pipe that is part of the fuel cell system and communicates with the fuel cell and passes off-gas that is heated and discharged in the fuel cell is used as a snow melting means, the heat of the off-gas is used to melt the snow. I can do it.

  A vehicle fuel gas detection device according to the present invention is a vehicle provided with a fuel gas detector provided on an upper part of an installation site of a fuel cell system having a fuel cell that generates power using fuel gas, and detects leaked fuel gas. In the fuel gas detector for a vehicle, a heat generating device provided in the vehicle is disposed as snow melting means at the installation site. If an existing heat generating device mounted on a vehicle is used as a snow melting means, it is not necessary to provide a new heat source in the vehicle.

  ADVANTAGE OF THE INVENTION According to this invention, it can prevent that a fuel gas detector cannot detect fuel gas, such as leaked hydrogen gas, by being covered with snow.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing an arrangement location of a vehicle fuel gas detection device 1 in a vehicle 30 equipped with the vehicle fuel gas detection device 1 according to the present embodiment. The vehicle fuel gas detection device 1 is disposed on the lower surface side of the floor 31 of the vehicle 30 and in the vicinity of the fender 33 on the rear wheel 32 side. The underside of the vehicular fuel gas detection device 1 is covered with an under cover 34.

  A vehicle 30 equipped with the vehicle fuel gas detection device 1 uses a fuel cell 35 that generates power using fuel gas as a power source. In the present embodiment, hydrogen gas is used as the fuel gas of the fuel cell 35. The fuel cell 35 is a so-called solid polymer electrolyte fuel cell, in which hydrogen gas and oxidizing gas (oxygen gas, usually oxygen gas contained in the air) are applied to a predetermined catalyst such as platinum on both surfaces of the electrolyte membrane. Electricity is taken out by reacting on a membrane-electrode assembly (MEA) in which an electrode including the electrode is formed. The vehicle 30 includes a fuel cell 35, a fuel reservoir 36 that stores hydrogen gas, a pipe 37 that communicates between the fuel reservoir 36 and the fuel cell 35, and supplies fuel gas to the fuel cell 35. A fuel cell system 38 is provided.

  FIG. 2 is a schematic configuration diagram (side view) of the vehicle fuel gas detection device 1 viewed from the side. FIG. 3 is a schematic configuration diagram (top view) of the vehicle fuel gas detection device 1 as seen from above. In the present embodiment, the vehicle fuel gas detection device 1 is a device that mainly detects hydrogen gas leaking from a plurality of fuel reservoirs 36 installed on the lower surface of the floor 31. In the present embodiment, the fuel reservoir 36 is a general hydrogen gas tank 36 that stores hydrogen gas (including a case where it is stored in a liquid state). The plurality of hydrogen gas tanks 36 are connected to a pipe 37 for supplying hydrogen gas to the fuel cell 35. The hydrogen gas tank 36 is formed of a cylindrical container, and a cylindrical body portion is fixed to the lower surface of the floor 31 by a predetermined fixing means (not shown). That is, the hydrogen gas tank 36 is fixed in a lying state. A lower side of the hydrogen gas tank 36 fixed in a lying state is covered with an under cover 34.

  In the present embodiment, the space between the lower surface of the floor 31 and the under cover 34 is an installation room 40 (installation site) in which the hydrogen gas tank 36 is installed. The installation site is a place where the fuel cell system 38 is installed, and includes not only a space divided as a room but also a space from which a part of the room is partially removed. In the present embodiment, the installation chamber 40 is not a complete sealed space but is in a situation where outside air can enter inside. Further, since the vehicular fuel gas detection device 1 is disposed in the vicinity of the fender 33 on the rear wheel 32 side, the snow S that has entered from the gap between the rear wheel 32 and the fender 33 enters the installation chamber 40. Is in a situation to get. For example, in FIG. 2, snow S enters the installation room 40 in the direction of the arrow indicated by the solid line.

  In the present embodiment, the lower surface of the floor 31 is the ceiling 41 of the installation room 40. A fuel gas collecting means 2 for collecting fuel gas such as leaked hydrogen gas is provided on the ceiling 41 (upper part of the installation site) of the installation chamber 40. The fuel gas collection means 2 is a fuel gas collection recess 2 having a recess. The fuel gas collecting recess 2 is formed by recessing the ceiling 41 upward. The fuel gas collecting recess 2 is a container-like recess having an opening 12 on the lower side and a bottomed portion 13 on the upper side. The fuel gas collecting recess 2 has a tapered shape in which the interval between the side walls 14 is gradually narrowed from the opening 12 to the bottomed portion 13 in order to easily collect the leaked hydrogen gas. For example, when hydrogen gas leaks from the hydrogen gas tank 36, the leaked hydrogen gas rises from the leak location 44 and enters the fuel gas collection recess 2 from the opening 12, as shown by the dashed arrow in FIG. 2. enter. Thereafter, the hydrogen gas rises toward the bottomed portion 13 along the side wall 14 in the fuel gas collecting recess 2 having a tapered shape. In this way, the leaked hydrogen gas is collected in the bottomed portion 13 of the fuel gas collecting recess 2.

  A fuel gas detector 3 for detecting leaked fuel gas is provided in the fuel gas collecting recess 2. In the present embodiment, a hydrogen gas detector 3 for detecting leaked hydrogen gas is provided. As the hydrogen gas detector 3, a known hydrogen gas detector 3 can be used. The hydrogen gas detector 3 is installed on the bottomed portion 13 in the fuel gas collecting recess 2 where the leaked hydrogen gas collects with the detection unit 15 for detecting hydrogen gas facing downward. The hydrogen gas detector 3 detects leakage of hydrogen gas when the hydrogen gas comes into contact with the detection unit of the hydrogen gas detector 3. The fuel gas detector 3 such as the hydrogen gas detector 3 is located at a position higher than the fuel reservoir 36 or the like serving as a leakage source when the fuel gas is lighter than air such as hydrogen gas or fuel gas. It is desirable to be installed at the highest position in the installation room 40.

  Below the hydrogen gas detector 3, snow melting means 4 is provided. The snow melting means 4 melts the snow S that has entered the installation chamber 40. In the present embodiment, the snow melting means 4 is an electric heater 4A that uses a battery 42 mounted on the vehicle as a power source. The electric heater 4A is suspended and fixed to the lower surface of the floor 31 (ceiling 41 in the installation chamber 40) by fixing means (not shown).

  By the way, when snow enters the installation chamber 40, the snow may enter the fuel gas collecting recess 2. If snow enters the fuel gas collecting recess 2 and the fuel gas detector 3 is covered with snow, the contact between the detection unit 15 of the fuel gas detector 3 and hydrogen gas is blocked by snow, and hydrogen gas Cannot be detected. Therefore, the snow melting means 4 melts at least the snow that has entered the fuel gas collecting recess 2 so that the fuel gas detector 3 can detect the fuel gas.

  Incidentally, there is a fuel gas detector 3 that generates heat (for example, the detector 15 generates heat). Therefore, even if snow adheres to this type of fuel gas detector 3, the snow can be melted to some extent by the heat generated by the fuel gas detector 3. However, when this type of fuel gas detector 3 is provided in the fuel gas collecting recess 2, the amount of snow covering the fuel gas detector 3 increases, and only by the heat generated by the fuel gas detector 3, In some cases, the snow in the fuel gas collecting recess 2 cannot be melted. However, even in such a case, the vehicular fuel gas detection device 1 includes the snow melting means 4 below the fuel gas collection recess 2, so that the snow in the fuel gas collection recess 2 is reliably melted. I can do it.

  It is desirable that snow other than the fuel gas collecting recess 2 is melted by the snow melting means 4 as much as possible. If the snow in the entire installation chamber 40 can be melted, the leaked hydrogen gas is collected in the fuel gas collection recess 2 without being blocked by the snow in the installation chamber 40, and is detected by the fuel gas detector 3. Detected.

  The distance between the snow melting means 4 and the fuel gas detector 3 above the snow melting means 4 is set as appropriate depending on the snow melting performance of the snow melting means 4 such as the amount of heat generated by the electric heater 4A, and at least the fuel gas collecting recess. 2 is set to an interval that can melt the snow that has entered inside. The snow melting performance of the snow melting means 4 such as the temperature of the electric heater 4A is also set as appropriate.

  The vehicle fuel gas detection device 1 according to the present embodiment includes a temperature sensor 5 that monitors the temperature in the installation chamber 40 and detects the temperature in the installation chamber 40 (installation site). The temperature in the installation chamber 40 is usually the same level as the outside air. The detection result of the temperature sensor 5 is sent to the control unit 6 connected to the temperature sensor 5 via the signal line 16.

  The control unit 6 is composed of a one-chip microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, and the like. When receiving the detection result signal sent from the temperature sensor 5, the controller 6 determines whether or not to start the snow melting means 4. When it is determined that the snow melting means 4 is to be started, the control unit 6 starts the snow melting means 4 (electric heater 4A). Specifically, by driving a relay 43 provided between the electric heater 4A and the battery 42, power supply from the battery 42 is started and the electric heater 4A is started. The electric heater 4A may have a mesh structure. By providing the mesh structure, the leaked gas such as fuel gas can pass through the electric heater 4A. The function of the control unit 6 may be performed by an engine control unit (engine ECU, not shown) that performs engine control of the vehicle 30.

  Here, the procedure for melting the snow when the snow melting means 4 of the vehicle fuel gas detection device 1 is started will be described with reference to FIGS. FIG. 4 is a flowchart showing a procedure in which the vehicular fuel gas detection device 1 operates and the snow melting means 4 starts. When driving the vehicle 30 during snowfall (at the time of snowfall), as shown in FIG. 2, snow may enter from the gap between the rear wheel 32 and the fender 33 and further snow may enter the installation room 40. In such a case, in step 10 (S10), the temperature sensor 5 that monitors the temperature in the installation chamber 40 detects the temperature in the installation chamber 40. The temperature sensor 5 outputs the detection result to the control unit 6. In response to the output of the temperature sensor 5, the controller 6 determines whether or not to start the electric heater 4 </ b> A that is the snow melting means 4 by comparing the temperature in the setting chamber 40 with a predetermined value. (S12). Here, the predetermined value can be determined in association with, for example, a temperature (for example, 0 ° C.) at which the snow that has entered in the installation room 40 is not easily melted. When it is determined that the temperature in the installation chamber 40 is 0 ° C. or less, the control unit 6 sends a command for operating the relay 43 to the relay 43. Thereafter, the relay 43 is actuated in response to the command, power is supplied from the battery 42, and the electric heater 4A is started. After the start-up, the electric heater 4A melts the snow that has generated heat and entered the installation room (S14). On the other hand, when it is determined that the temperature in the installation chamber 40 exceeds 0 ° C., the control unit 6 does not issue the command and proceeds from step 12 (S12) to step 10 (S10) again. The temperature in the installation chamber 40 is continuously monitored by the temperature sensor 5. In this way, in the vehicle fuel gas detection device 1, the snow melting means 4 is started to melt the snow. In other embodiments, the snow melting means 4 may be started and stopped by manual operation.

  Hereinafter, the vehicle fuel gas detection device 11 according to another embodiment will be described. FIG. 5 is a schematic configuration diagram (side view) of the vehicle fuel gas detection device 11 viewed from the side. FIG. 6 is a schematic configuration diagram (top view) of the vehicle fuel gas detection device 11 as seen from above. The snow melting means 4 of the vehicle fuel gas detection device 11 is a pipe provided in the fuel cell system 38 and is an exhaust gas pipe 4B through which exhaust gas discharged from the fuel cell 35 is passed. The other basic configuration is the same as that of the vehicle fuel gas detection device 1. About the same structure, in FIG.5 and FIG.6, it showed using the same code | symbol as the structure of the fuel gas detection apparatus 1 for vehicles.

  The fuel cell 35 generates power in a state of about 80 ° C. From the fuel cell 35, an off-gas such as unused oxidizing gas (air) is discharged in a state of being heated in the fuel cell 35. The snow melting means 4B in this embodiment melts snow using the heat of this off gas. The exhaust gas pipe 4B is arranged in the installation chamber 40, and the off gas discharged from the fuel cell 35 is passed through the exhaust gas pipe 4B, whereby heat is given into the installation chamber 40. The exhaust gas pipe 4 </ b> B is passed under the fuel gas detector 3. As shown in FIG. 6, the exhaust gas pipe 4B is a ladder-like pipe in which one pipe branches into three along the way, and then the branched pipes merge again into one pipe. is there. As shown in FIG. 5, the exhaust gas pipe 4 </ b> B partially penetrates the side wall 14 of the fuel gas collection recess 2, passes through the fuel gas collection recess 2 and below the fuel gas detector 3. Furthermore, it penetrates the other side wall 14 facing the side wall 14. The off-gas flows in the exhaust gas pipe 4B in the direction of the arrow in FIGS. The exhaust gas pipe 4B is made of a material having excellent thermal conductivity such as a metal material such as aluminum or stainless steel. The off gas that has passed through the exhaust gas pipe 4 </ b> B is discharged to the outside of the vehicle 30. According to the vehicle fuel gas detection device 11, the off-gas discharged from the fuel cell 35 can be effectively used.

  In still another embodiment, an existing heat generating device (not shown) provided in the vehicle 30 is disposed at a predetermined location such as below the fuel gas detector 3 in the installation chamber 40, so that the heat generating device is connected to the snow melting means 4. It may be used as Thus, if the heat generated by the existing heat generating device can be used, there is no need to provide a heat source for melting the snow again.

  In the above embodiment, the devices 1 and 11 for detecting the leakage of hydrogen gas have been exemplified. However, in another embodiment, the device may be a device for detecting the leakage of methane gas, for example. In addition to the case where the hydrogen gas stored in the fuel storage 36 is directly used, the hydrogen gas supplied to the fuel cell 35 may be a hydrogen gas obtained by reforming methane gas. In this case, a methane gas reservoir is mounted on the vehicle, and methane gas can leak from the methane gas reservoir or the like. Therefore, in such a case, the vehicle fuel gas detection device of the present invention is a vehicle methane gas detection device including a methane gas detector as a fuel gas detector. In this case, an apparatus that detects both methane gas and hydrogen gas may be used.

  In still another embodiment, the vehicular fuel gas detection device may include a notification unit that notifies the start state of the snow melting unit by a lighting device that is turned on when the snow melting unit 4 is started and is turned off when the snow melting unit 4 is stopped. If a notification means that turns on and off when the snow melting means is started and stopped is provided in the vehicle (for example, an existing instrument panel), the driver can grasp the start state of the snow melting means by the notification means.

  In still another embodiment, the vehicle fuel gas detection device may include a plurality of snow melting means 4. For example, a plurality of electric heaters 4A may be provided, or both the electric heater 4A and the exhaust gas pipe 4B may be provided.

It is explanatory drawing which shows the arrangement | positioning location of the vehicle fuel gas detection apparatus in the vehicle carrying the vehicle fuel gas detection apparatus which concerns on this embodiment. It is the side view which showed schematic structure of the fuel gas detection apparatus for vehicles. It is the top view which showed schematic structure of the fuel gas detection apparatus for vehicles. It is a flowchart which shows the operation | movement procedure of the fuel gas detection apparatus for vehicles. It is the side view which showed schematic structure of the fuel gas detection apparatus for vehicles which concerns on other embodiment. It is the top view which showed schematic structure of the fuel gas detection apparatus for vehicles which concerns on other embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,11 Vehicle fuel gas detection apparatus, 2 Fuel gas collection means (recess), 3 Fuel gas detector (hydrogen gas detector), 4 Snow melting means, 4A Electric heater, 4B Exhaust gas piping, 5 Temperature sensor, 6 Control part, 12 Opening part of fuel gas collecting concave part, 13 Bottomed part of fuel gas collecting concave part, 14 Side wall of fuel gas collecting concave part, 15 Detection part of fuel gas detector, 16 Signal line, 30 vehicle, 31 vehicle Floor, 32 rear wheels, 33 rear wheel fender, 34 under cover, 35 fuel cell, 36 fuel reservoir (hydrogen gas tank), 37 piping, 38 fuel cell system, 40 installation room, 41 installation room ceiling, 42 Battery, 43 Relay, 44 Leakage location, S Snow.

Claims (7)

In a vehicle fuel gas detection device comprising: a fuel cell system having a fuel cell that generates power using fuel gas; and a fuel gas detector that detects fuel gas leaked from the fuel cell system.
Fuel gas collecting means for collecting fuel gas in the fuel gas detector;
A vehicle fuel gas detection device, comprising: a snow melting means disposed in the vicinity of the fuel gas collecting means for melting snow. The vehicle fuel gas detection device according to claim 1,
The fuel gas detection device for vehicles, wherein the fuel gas collecting means is a recess provided at an upper portion of a fuel cell system installation site. The vehicle fuel gas detection device according to claim 2,
A vehicle fuel gas detection device, wherein the snow melting means is disposed below the fuel gas collecting means and melts snow at least in the recess. In the fuel gas detection device for vehicles according to any one of claims 1 to 3,
The apparatus further comprises:
A temperature sensor for detecting the temperature of the fuel cell system installation site;
A vehicle fuel gas detection apparatus comprising: a control unit that starts the snow melting means based on a detection value of a temperature sensor. In the fuel gas detection device for vehicles according to any one of claims 1 to 4,
The vehicle fuel gas detection device, wherein the snow melting means is an electric heater. In a vehicular fuel gas detection device including a fuel gas detector that is provided at an upper portion of an installation site of a fuel cell system having a fuel cell that generates power using fuel gas and detects leaked fuel gas,
A fuel gas detection apparatus for a vehicle, comprising: a snow melting means which is a pipe provided in the fuel cell system and which is an exhaust gas pipe through which exhaust gas discharged from the fuel cell is passed. In a vehicular fuel gas detection device including a fuel gas detector that is provided at an upper portion of an installation site of a fuel cell system having a fuel cell that generates power using fuel gas and detects leaked fuel gas,
A fuel gas detection device for a vehicle, wherein a heat generating device provided in the vehicle is disposed as snow melting means at the installation site.

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