JP5062215B2 - In-vehicle fuel cell system and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system for vehicle that is mounted on a vehicle in a saved space and in a light weight. <P>SOLUTION: A pump 410 to be used for circulating a hydrogen gas in a normal operation is used for a low temperature operation for extracting a hydrogen gas from a hydrogen storage alloy tank 200. One pump is used for a circulating and extracting hydrogen and a space for mounting on a vehicle can be saved and a weight can be made lighter. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an in-vehicle fuel cell system suitable for being mounted on a vehicle such as an automobile.

  A fuel cell that generates electric power upon receiving supply of hydrogen gas from a high-pressure hydrogen gas tank or a hydrogen storage alloy tank is highly promising as a power source for electric vehicles and the like because of its high energy efficiency.

  However, when such a fuel cell is used as a power source for a vehicle, not only the fuel cell but also a hydrogen gas supply source such as the above-described high-pressure hydrogen gas tank or hydrogen storage alloy tank, and the hydrogen gas supply source to the fuel cell are used. It is necessary to mount a fuel cell system including a hydrogen gas passage for feeding hydrogen gas on a vehicle.

JP-A-7-192743

  When the fuel cell system is mounted on a vehicle, it is preferable that the fuel cell system can be mounted with the smallest possible space and the smallest possible space. Moreover, in order to handle highly flammable hydrogen gas, it is necessary to ensure high safety.

  Accordingly, an object of the present invention is to provide an in-vehicle fuel cell system that can solve the above-described problems and can be mounted on a vehicle with a small space and light weight, and can also ensure high safety. is there.

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 or application examples.
One embodiment of the present invention is a hydrogen gas storage unit capable of releasing stored hydrogen gas at a predetermined pressure, and an electric power received from the supply of the hydrogen gas released from the hydrogen gas storage unit. An in-vehicle fuel cell system mounted on a vehicle,
A first flow path connecting the discharge port of the hydrogen gas storage unit and the supply port of the fuel cell, and supplying the hydrogen gas discharged from the hydrogen gas storage unit to the fuel cell; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A second channel extending toward the outside of the vehicle from a specific location located between the decompression unit and the fuel cell supply port in the first channel;
A relief valve disposed in the second flow path and capable of flowing and stopping gas by opening and closing;
With
The relief valve is opened when the pressure of the hydrogen gas existing in the flow path on the specific location side of the relief valve exceeds a reference pressure, and the hydrogen gas is removed from the first flow path through the first flow path. 2 to the outside through the flow path,
The discharge port of the second flow path is arranged so that the hydrogen gas to be discharged is directed to the road surface.
A fuel cell system according to a first application example of the present invention includes a hydrogen gas storage unit capable of releasing stored hydrogen gas at a predetermined pressure, and supply of the hydrogen gas released from the hydrogen gas storage unit. A fuel cell system for generating electric power upon receipt of the fuel cell system mounted on a vehicle,
A first flow path connecting the discharge port of the hydrogen gas storage unit and the supply port of the fuel cell, and supplying the hydrogen gas discharged from the hydrogen gas storage unit to the fuel cell; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A second channel extending toward the outside of the vehicle from a specific location located between the decompression unit and the fuel cell supply port in the first channel;
A relief valve disposed in the second flow path and capable of flowing and stopping gas by opening and closing;
With
The relief valve is opened when the pressure of the hydrogen gas existing in the flow path on the specific location side of the relief valve exceeds a reference pressure, and the hydrogen gas is removed from the first flow path through the first flow path. The gist is to discharge to the outside through the two flow paths.

As described above, in the in-vehicle fuel cell system according to the first application example , when the pressure of the hydrogen gas exceeds the reference pressure, the relief valve is opened to discharge the hydrogen gas having a high pressure to the outside.

Therefore, according to the on-vehicle fuel cell system of the first application example , even if an abnormality such as a failure of the decompression unit occurs and the hydrogen gas pressure becomes abnormally high, the hydrogen gas is immediately discharged to the outside. Therefore, there is no fear that the fuel cell will fail, and high safety can be ensured.

In the fuel cell system according to the first application example of the present invention, it is preferable that the discharge port of the second flow path is arranged so that the hydrogen gas to be discharged is directed to the road surface.

  By arranging in this way, the discharged hydrogen gas does not accumulate in a certain place in the vehicle, and higher safety can be obtained.

A vehicle-mounted fuel cell system according to a second application example of the present invention generates a power by receiving a supply of hydrogen gas supplied from the hydrogen gas supply unit for supplying hydrogen gas and the hydrogen gas supplied from the hydrogen gas supply unit. A fuel cell for discharging the remaining hydrogen gas, and an in-vehicle fuel cell system mounted on a vehicle,
A first flow path for connecting the supply port of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell with the hydrogen gas sent from the hydrogen gas supply unit; ,
A second flow that connects between the discharge port of the fuel cell and a specific location in the first flow path, and flows the hydrogen gas discharged from the fuel cell and returns it to the first flow path. Road,
A gas-liquid separation unit that is disposed in the second flow path and separates the water contained in the hydrogen gas discharged from the fuel cell into a liquid and a gas and removes only the liquid;
It is a summary to provide.

The hydrogen off-gas discharged from the fuel cell is wet and contains a considerable amount of moisture. Therefore, in the in-vehicle fuel cell system of the second application example , the gas-liquid separation unit arranged in the second flow path separates the moisture contained in the hydrogen gas into a liquid and a gas, and only the liquid To be removed.

Therefore, according to the on-vehicle fuel cell system of the second application example , when hydrogen gas is circulated and supplied to the fuel cell, the contained water is not supplied as a gas-liquid mixture, and the fuel cell system There is no risk of disturbing the power generation operation.

An in-vehicle fuel cell system according to a third application example of the present invention generates a power by receiving a supply of hydrogen gas supplied from the hydrogen gas supply unit for supplying hydrogen gas and the hydrogen gas supplied from the hydrogen gas supply unit. A fuel cell for discharging the remaining hydrogen gas, and an in-vehicle fuel cell system mounted on a vehicle,
A first flow path for connecting the supply port of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell with the hydrogen gas sent from the hydrogen gas supply unit; ,
A second flow that connects between the discharge port of the fuel cell and a specific location in the first flow path, and flows the hydrogen gas discharged from the fuel cell and returns it to the first flow path. Road,
A gas-liquid that is disposed between the specific location in the first flow path and the supply port of the fuel cell and separates the water contained in the hydrogen gas into a liquid and a gas and removes only the liquid. A separation unit;
It is a summary to provide.

When the temperature of the hydrogen gas flowing in the first flow path is low, when the hydrogen gas and the hydrogen gas returned from the second flow path are mixed by circulation, the moisture contained in the hydrogen gas May condense and become a gas-liquid mixture and be supplied to the fuel cell. Therefore, in the in-vehicle fuel cell system according to the third application example , the hydrogen gas is separated by the gas-liquid separation unit disposed on the fuel cell side from the specific location in the first flow path, that is, the portion where the hydrogen gas is mixed. The water contained in is separated into a liquid and a gas, and only the liquid is removed.

Therefore, according to the on-vehicle fuel cell system of the third application example , when hydrogen gas is supplied to the fuel cell, the contained moisture is not supplied as a gas-liquid mixture, and the fuel cell power generation operation is performed. There is no risk of hindrance.

A vehicle-mounted fuel cell system according to a fourth application example of the present invention includes a hydrogen gas storage unit capable of releasing stored hydrogen gas at a predetermined pressure, and the hydrogen gas released from the hydrogen gas storage unit. A fuel cell system that generates electric power upon receipt of the supply, and is a vehicle-mounted fuel cell system mounted on a vehicle,
A first flow path connecting the discharge port of the hydrogen gas storage unit and the supply port of the fuel cell, and supplying the hydrogen gas discharged from the hydrogen gas storage unit to the fuel cell; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A temperature raising unit that is disposed between the pressure reducing unit in the first flow path and the supply port of the fuel cell, and raises the temperature of the hydrogen gas flowing through the first flow path;
It is a summary to provide.

If the pressure of the hydrogen gas is reduced by the decompression unit, the hydrogen gas may expand rapidly and the temperature may drop rapidly. Therefore, in the in-vehicle fuel cell system according to the fourth application example , the temperature of the hydrogen gas is raised by the temperature raising unit arranged on the fuel cell side with respect to the pressure reducing unit in the first flow path.

Therefore, according to the on-vehicle fuel cell system of the fourth application example , since the hydrogen gas is supplied to the fuel cell at an appropriate temperature, the temperature inside the fuel cell is not lowered, and an appropriate reaction temperature is achieved in the fuel cell. Can cause an electrochemical reaction.

An in-vehicle fuel cell system according to a fifth application example of the present invention generates a power by receiving a supply of hydrogen gas supplied from the hydrogen gas supply unit for supplying hydrogen gas and the hydrogen gas supplied from the hydrogen gas supply unit. A fuel cell for discharging the remaining hydrogen gas, and an in-vehicle fuel cell system mounted on a vehicle,
A first flow path for connecting the supply port of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell with the hydrogen gas sent from the hydrogen gas supply unit; ,
A second flow that connects between the discharge port of the fuel cell and a specific location in the first flow path, and flows the hydrogen gas discharged from the fuel cell and returns it to the first flow path. Road,
A pump that is disposed in the second flow path, causes the hydrogen gas flowing through the second flow path to flow toward the specific location, and circulates the hydrogen gas;
A control unit for controlling the hydrogen gas supply unit and the pump;
With
The control unit, when starting the fuel cell system, causes the hydrogen gas to be sent from the hydrogen gas supply unit and drives the pump to cause a flow in the flow path through which the hydrogen gas flows, The gist is to homogenize the impurities present in the flow path and the delivered hydrogen gas by stirring.

A control method according to a sixth application example of the present invention includes a hydrogen gas supply unit for supplying hydrogen gas, and generates power by receiving the supply of the hydrogen gas sent from the hydrogen gas supply unit. A fuel cell for discharging the remaining hydrogen gas, and a control method for an in-vehicle fuel cell system mounted on a vehicle,
(A) a first connecting the outlet of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell by flowing the hydrogen gas delivered from the hydrogen gas supply unit; Connects between the flow path, the outlet of the fuel cell, and a specific location in the first flow path, and flows the hydrogen gas discharged from the fuel cell and returns it to the first flow path. A second flow path and a pump that is arranged in the second flow path and that flows the hydrogen gas flowing through the second flow path toward the specific location and circulates the hydrogen gas are prepared. Process,
(B) at the time of starting the fuel cell system, sending the hydrogen gas from the hydrogen gas supply unit;
(C) driving the pump to cause a flow in the flow path through which the hydrogen gas flows, and stirring and homogenizing impurities present in the flow path and the delivered hydrogen gas;
It is a summary to provide.

When the fuel cell system is started, the hydrogen gas flow path in the fuel cell may contain impurities such as nitrogen. For this reason, the output voltage of the fuel cell does not readily increase to a desired voltage simply by flowing hydrogen gas through the hydrogen gas flow path. Therefore, in the on- vehicle fuel cell system of the fifth application example or the control method of the sixth application example , when the fuel cell system is started, the hydrogen gas is sent from the hydrogen gas supply unit and the pump is driven to A flow is caused in the flow path where the gas should flow, and impurities such as nitrogen existing in the flow path and the delivered hydrogen gas are agitated and made uniform.

  In this way, by making the remaining impurities such as nitrogen and the delivered hydrogen gas uniform, the output voltage of the fuel cell immediately rises to a desired voltage and can be supplied to a load or the like.

1 is a configuration diagram showing an in-vehicle fuel cell system as a first embodiment of the present invention. FIG. It is sectional drawing which shows one specific example of the gas-liquid separator used in FIG. 2 is a flowchart showing an example of control contents of a control unit 50 when the fuel cell system of FIG. 1 is started. It is a block diagram which shows the vehicle-mounted fuel cell system as 2nd Example of this invention. 5 is a flowchart showing an example of control contents of a control unit 50 at the start of the fuel cell system of FIG. 4.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. First embodiment:
A-1. Configuration of the first embodiment:
A-2. Operation of the first embodiment:
B. Second embodiment:
B-1. Configuration of the second embodiment:
B-2. Operation of the second embodiment:
C. Variations:

A. First embodiment:
A-1. Configuration of the first embodiment:
FIG. 1 is a block diagram showing an in-vehicle fuel cell system as a first embodiment of the present invention. The fuel cell system according to the present embodiment is mounted on a vehicle such as an automobile, and mainly includes a fuel cell 100 that generates power by receiving supply of hydrogen gas, and supplies hydrogen gas to the fuel cell 100. And a hydrogen storage alloy tank 200.

  Among these, the fuel cell 100 receives supply of an oxidizing gas (for example, air) containing oxygen in addition to hydrogen gas containing hydrogen, and at the hydrogen electrode and the oxygen electrode, according to the reaction formula shown below, It causes an electrochemical reaction and generates electric power.

  That is, when hydrogen gas is supplied to the hydrogen electrode and oxidizing gas is supplied to the oxygen electrode, the reaction of formula (1) occurs on the hydrogen electrode side, and the reaction of formula (2) occurs on the oxygen electrode side. As for, reaction of Formula (3) is performed.

H ₂ → 2H ⁺ + 2e ⁻ (1)
2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O (2)
H ₂ + (1/2) O ₂ → H ₂ O (3)
When such a fuel cell 100 is used as a power source for a vehicle, an electric motor (not shown) is driven by the electric power generated from the fuel cell 100, and the generated torque is transmitted to an axle (not shown). Get the driving force.

  The fuel cell 100 has a stack structure in which a plurality of single cells are stacked, and each single cell includes an electrolyte membrane (not shown) and a diffusion electrode (not shown) that sandwiches it from both sides. It consists of a certain hydrogen electrode and oxygen electrode, and two separators (not shown) sandwiching them from both sides. Concavities and convexities are formed on both surfaces of the separator, and a gas flow path in a single cell is formed between the sandwiched hydrogen electrode and oxygen electrode. Among these, the hydrogen gas supplied as described above is formed in the gas flow path in the single cell formed between the hydrogen electrode and the gas flow path in the single cell formed in the single cell formed between the oxygen electrode is oxidized. Each gas is flowing.

  On the other hand, the hydrogen storage alloy tank 200 includes a hydrogen storage alloy (not shown) therein. In general, a hydrogen storage alloy has an endothermic reaction when it is heated to release hydrogen, and when it is cooled, it has a property of generating a heat dissipation reaction and storing hydrogen. Therefore, when extracting hydrogen from the hydrogen storage alloy, the hydrogen storage alloy in the hydrogen storage alloy tank 200 is heated by a heat exchange system (not shown).

  Since the hydrogen storage alloy deteriorates when impurities are present, high-purity hydrogen is stored in the hydrogen storage alloy tank 200.

  In addition, as shown in FIG. 1, the fuel cell system of the present embodiment includes a hydrogen gas channel for circulating hydrogen gas in the system, an oxidizing gas channel for circulating oxidizing gas, and a control unit 50. It has.

  Among these, the hydrogen gas flow path includes a main flow path 401 from the discharge port of the hydrogen storage alloy tank 200 to the supply port of the fuel cell 100 and a main flow path 401 from the discharge port of the fuel cell 100 via a pump 410 described later. , A bypass channel 405 branched from the main channel 401 to the circulation channel 403, a discharge channel 407 for discharging impurities in the circulating hydrogen gas, and a pressure abnormality A relief channel 409 for discharging hydrogen gas at times.

  In the main flow path 401, a shut valve 202 is disposed at the discharge port of the hydrogen storage alloy tank 200, and a pressure sensor 400, a shut valve 402, and a pressure reducing valve 404 are disposed in the middle of the flow path. A shut valve 102 is disposed at the supply port. In the circulation channel 403, the shut valve 104 is disposed at the discharge port of the fuel cell 100, and the gas-liquid separator 406, the shut valve 408, and the pump 410 are disposed in the middle of the channel. Further, a shut valve 412 is disposed in the bypass flow path 405, a shut valve 414 is disposed in the discharge flow path 407, and a relief valve 416 is disposed in the relief flow path 409.

  On the other hand, the oxidizing gas channel includes an oxidizing gas supply channel 501 for supplying oxidizing gas to the fuel cell 100, and an oxygen off-gas discharging channel 503 for discharging oxygen off-gas discharged from the fuel cell 100. I have.

  An air cleaner 502, a compressor 504, and a humidifier 506 are disposed in the oxidizing gas supply channel 501. In addition, a gas-liquid separator 508 and a combustor 510 are disposed in the oxygen off-gas discharge channel 503.

  In addition, the control unit 50 inputs the detection result from the pressure sensor 400, and controls each valve 102, 104, 202, 402, 408, 412, 414, the pump 410, and the compressor 504, respectively. Note that control lines and the like are omitted for easy viewing of the drawing.

A-2. Operation of the first embodiment:
First, the flow of the oxidizing gas will be briefly described. By driving the compressor 504 by the control unit 50, air in the atmosphere is taken in as oxidant gas and purified by the air cleaner 502, then passes through the oxidant gas supply channel 501, and passes through the humidifier 506 to the fuel cell 100. Supplied. The supplied oxidizing gas is used as the above-described electrochemical reaction in the fuel cell 100 and then discharged as an oxygen off gas. The discharged oxygen off gas passes through the oxygen off gas discharge passage 503 and is discharged into the atmosphere outside the vehicle via a gas-liquid separator 508 and a combustor 510 described later.

  Next, the flow of hydrogen gas will be described in detail. The control unit 50 causes the shut valve 202 of the hydrogen storage alloy tank 200 and the shut valves 102 and 104 of the fuel cell 100 to be basically opened during operation of the fuel cell system, but closed when stopped.

  In addition, during normal operation, the control unit 50 opens the shut valve 402 of the main flow path 401 and the shut valve 408 of the circulation flow path 403 in addition to these, but the shut valve 412 of the bypass flow path 405, The shut valve 414 of the discharge channel 407 is closed. As will be described later, the relief valve 416 is closed except when the pressure is abnormal. The pressure sensor 400 detects the pressure of the hydrogen gas released from the hydrogen storage alloy tank 200.

  During normal operation, as described above, the hydrogen gas storage alloy in the hydrogen storage alloy tank 200 is heated by the heat exchange system to release the hydrogen gas, and the released hydrogen gas passes through the main flow path 401 to the fuel cell. 100. The supplied hydrogen gas is used as the above-described electrochemical reaction in the fuel cell 100 and then discharged as a hydrogen off gas. The discharged hydrogen off gas is returned to the main flow path 401 through the circulation flow path 403 and supplied to the fuel cell 100 again. At this time, when the pump 410 provided in the middle of the circulation flow path 403 is driven, the hydrogen off-gas passing through the circulation flow path 403 is vigorously sent out to the main flow path 401. Thus, during normal operation, hydrogen gas circulates through the main flow channel 401 and the circulation channel 403.

  In this manner, by returning the hydrogen off-gas to the main flow path 401 and circulating the hydrogen gas, even if the amount of hydrogen used in the fuel cell 100 is the same, the apparent amount of hydrogen gas supplied to the fuel cell 100 is apparent. Since the flow rate increases and the flow rate increases, this is advantageous from the viewpoint of supplying hydrogen to the fuel cell 100, and the output voltage of the fuel cell 100 also increases.

  Further, in the fuel cell 100, impurities such as nitrogen contained in the oxidizing gas permeate the electrolyte membrane from the oxygen electrode side and leak to the hydrogen electrode side. Therefore, if hydrogen gas is not circulated, the impurities accumulate in the hydrogen electrode at the rear stage in the fuel cell 100, and the range expands with time. As a result, the fuel cell 100 may interfere with the power generation operation, and the output voltage may drop. However, as described above, if the hydrogen gas is circulated, the impurities are uniformized in the entire hydrogen gas flow path, so that the above-described problems can be solved.

  The driving of the pump 410 is controlled by the control unit 50, and the flow rate of the hydrogen off-gas flowing through the circulation flow path 403 is changed according to the power consumption generated by the fuel cell 100.

  Further, since the pressure of the hydrogen gas released from the hydrogen storage alloy tank 200 is a high pressure that does not exceed 1 MPa at the maximum, if the hydrogen gas is supplied to the fuel cell 100 as it is, the pressure is too high and the fuel cell 100 has a problem. It will occur. Therefore, the pressure of the hydrogen gas is reduced from 1 MPa to about 0.2 to 0.3 MPa appropriate for the fuel cell 100 by the pressure reducing valve 404 provided in the middle of the main flow path 401, and then supplied to the fuel cell 100. Like to do.

  Further, as described above, on the oxygen electrode side in the fuel cell 100, water (H 2 O) is generated according to the equation (2), and the water enters the hydrogen electrode side through the electrolyte membrane from the oxygen electrode side as water vapor. Therefore, the hydrogen off gas discharged from the fuel cell 100 is wet and contains a considerable amount of moisture. Therefore, if this hydrogen off-gas is sent out to the main flow path 401 via the pump 410 as it is, the contained moisture is not vaporized sufficiently and becomes a gas-liquid mixture, and is supplied to the fuel cell 100 together with hydrogen. There is a risk of being supplied and sticking in the single cell of the fuel cell 100 to block the hydrogen gas flow path. When the water blocks the hydrogen gas flow path in the single cell and stops the flow of hydrogen gas, the output voltage of the single cell decreases, and the power generation amount of the entire fuel cell 100 also decreases.

  Therefore, a gas-liquid separator 406 is provided in the middle of the circulation flow path 403, and the gas-liquid separator 406 separates the water contained in the hydrogen off gas into gas and liquid, removes the liquid component, and only the gas (water vapor) component. Are sent to the pump 410 together with other gases. As a result, the moisture contained in the hydrogen gas is only a gas component, and moisture is not supplied to the fuel cell 100 as a gas-liquid mixture, and there is no possibility of hindering the power generation operation.

  FIG. 2 is a cross-sectional view showing a specific example of the gas-liquid separator used in FIG. The hydrogen off gas containing a large amount of moisture flows into the cylinder 604 from the inlet 602. The inflowing hydrogen off gas descends while spirally turning along the inner wall in the cylinder 604. At this time, the contained moisture is condensed, and the liquid component adheres as droplets to the inner wall of the cylinder 604, falls down along it, and is collected in the liquid pool 608. On the other hand, the gas (water vapor) component flows out from the outlet 606 through the gas flow path 610 together with other gases. Thus, it becomes possible to gas-liquid-separate water into liquid and gas.

  Further, when it is detected that the water collected in the liquid pool 908 has reached a predetermined amount by a level sensor (not shown), the cock 612 is automatically turned off by an auto drain mechanism (not shown). Open and discharged to the outside.

  Further, as described above, the hydrogen gas is circulated in order to make the impurities contained in the hydrogen gas uniform. However, even if the hydrogen gas is made uniform in this way, the impurities always leak from the oxygen electrode side to the hydrogen electrode side in the fuel cell 100. Therefore, after a long period of time, the hydrogen gas becomes uniform. The concentration of the impurities therein gradually increases, and the hydrogen concentration decreases accordingly, which may adversely affect the power generation operation of the fuel cell 100.

  Therefore, a shut valve 414 is provided in the discharge flow path 407 branched from the circulation flow path 403, and the shut valve 414 is periodically opened by the control unit 50 to discharge the hydrogen gas containing the circulating impurities. Thus, the hydrogen gas containing impurities is replaced with pure hydrogen gas from the hydrogen storage alloy tank 200. As a result, the concentration of impurities in the hydrogen gas decreases, and conversely, the concentration of hydrogen increases, so that the fuel cell 100 can appropriately generate power.

  Further, as described above, since water vapor also leaks from the oxygen electrode side to the hydrogen electrode side in the fuel cell 100, depending on the temperature, the water vapor condenses and sticks in the single cell, and the flow of hydrogen gas is reduced. There is also a risk of stopping. However, as described above, when the shut-off valve 414 is opened and the hydrogen gas is discharged, a rapid flow occurs in the hydrogen gas due to the pressure difference. Therefore, it is possible to blow away the moisture condensed by the momentum.

  Even if the shut valve 414 is opened during the power generation operation of the fuel cell 100, there is no problem because the output voltage of the fuel cell 100 only drops for a moment and does not cause a large voltage drop. The opening time of the shut valve 414 is preferably 1 sec or less, and more preferably about 500 msec, for example.

  The hydrogen gas discharged from the shut valve 414 passes through the discharge flow path 407, is sent to the oxygen off gas discharge flow path 503, and is mixed with the oxygen off gas flowing through the oxygen off gas discharge flow path 503. The mixed gas flows into the combustor 510 through the gas-liquid separator 508. The combustor 510 includes a platinum catalyst 512, and further reduces hydrogen by reacting hydrogen contained in the mixed gas with oxygen by combustion. Thereafter, the mixed gas flowing out of the combustor 510 is discharged into the atmosphere.

  The above is the flow of hydrogen gas during normal operation. Next, the flow of hydrogen gas at the time of cold start will be described.

  Generally, in the hydrogen storage alloy, the higher the temperature, the higher the pressure of released hydrogen, and the lower the temperature, the lower the pressure of released hydrogen. Therefore, as the temperature of the hydrogen storage alloy tank becomes lower, hydrogen is less likely to be released. Therefore, when starting at a low temperature, it is necessary to quickly warm the hydrogen storage alloy tank with a heater or the like so that hydrogen is easily released. However, in this way, the method of heating using a heater requires a large amount of electrical energy, and thus is inappropriate as a vehicle-mounted fuel cell system.

  Therefore, in this embodiment, at the time of low temperature start, hydrogen gas is drawn out from the hydrogen storage alloy tank 200 by the pump 410 instead of being heated by a heater or the like.

  FIG. 3 is a flowchart showing an example of control contents of the control unit 50 when the fuel cell system of FIG. 1 is started.

  At the start of the fuel cell system, the controller 50 first opens the shut valve 202 of the hydrogen storage alloy tank 200 and the shut valves 102 and 104 of the fuel cell 100 from the closed state as shown in FIG. S102). Next, the control unit 50 inputs the hydrogen gas pressure detected by the pressure sensor 400 (step S104), and determines whether or not the pressure exceeds a preset reference pressure (step S106).

  If the ambient temperature is appropriate and hydrogen gas having a sufficient pressure is released from the hydrogen storage alloy tank 200 and the pressure exceeds the reference pressure, the control is performed to shift to the normal operation described above. The unit 50 opens the shut valve 402 of the main flow path 401 and the shut valve 408 of the circulation flow path 403, closes the shut valve 412 of the bypass flow path 405, and the shut valve 414 of the discharge flow path 407 (step). S114), the pump 410 is driven at the standard rotation (step S116), and the hydrogen gas is circulated as described above.

  However, if the ambient temperature is low, hydrogen gas is not easily released from the hydrogen storage alloy tank 200, and the pressure is below the reference pressure, the operation moves to low temperature start, and the control unit 50 The shut valve 402, the shut valve 408 of the circulation flow path 403, and the shut valve 414 of the discharge flow path 407 are closed, and the shut valve 412 of the bypass flow path 405 is opened (step S108). Further, the control unit 50 drives the pump 410 at a high rotational speed (step S110). Thereby, even if the temperature of the hydrogen storage alloy tank 200 is low and the pressure of the released hydrogen gas is low, the stored hydrogen gas is sufficiently extracted from the hydrogen storage alloy tank 200. The drawn hydrogen gas enters the bypass channel 405 from the main channel 401 and then returns to the main channel 401 through the circulation channel 403 and is supplied to the fuel cell 100. The supplied hydrogen gas is subjected to an electrochemical reaction in the fuel cell 100 and then becomes hydrogen off-gas and is discharged to the circulation flow path 403. Note that the concentration of impurities contained in the hydrogen off-gas increases as time passes. Therefore, in order to remove the impurities, the shut-off valve 414 is sometimes opened to release the hydrogen off-gas from the discharge passage 407.

  The control unit 50 stands by in this state until the pressure of the hydrogen gas released from the hydrogen storage alloy tank 200 exceeds the reference pressure (step S112). However, after a while after the fuel cell system is started, a heat exchange system (not shown) is fully activated, and the hydrogen storage alloy in the hydrogen storage alloy tank 200 is also heated. Hydrogen gas having a sufficient pressure is released from the tank 200. Then, the pressure exceeds the reference pressure, and the control unit 50 opens the shut valve 402 of the main flow path 401 and the shut valve 408 of the circulation flow path 403, and shuts the shut valve 412 of the bypass flow path 405 and the discharge flow path. The shut valve 414 of 407 is closed (step S114), the pump 410 is driven at the standard rotation (step S116), and the operation is shifted to the normal operation described above.

  Thus, at the time of cold start, by using the pump 410, the hydrogen occluded in the hydrogen occlusion alloy tank 200 can be taken out without requiring a lot of electric energy.

  Further, in this embodiment, the pump 410 used for circulating the hydrogen gas during normal operation is shared in order to draw out the hydrogen gas from the hydrogen storage alloy tank 200 at the time of low temperature start, so that the space for mounting the pump is reduced. In addition to saving, weight can be reduced.

  Moreover, as the pump 410, it is necessary to use a pump that can change the flow rate by changing the rotation speed between when the hydrogen gas is circulated and when the hydrogen gas is drawn out. That is, when hydrogen gas is circulated, the compression ratio (pump discharge pressure / pump suction pressure) is low, so power is low. However, when hydrogen gas is drawn, the compression ratio is high and necessary. The power to become higher.

  The above is the flow of hydrogen gas at the time of cold start. Next, the operation when stopped will be described.

  As described above, in the fuel cell 100, impurities such as nitrogen and water vapor leak from the oxygen electrode side to the hydrogen electrode side through the electrolyte membrane, and such hydrogen gas is circulated during normal operation. Contains some impurities. Thereafter, when the operation of the fuel cell system is stopped, the operation of the hydrogen storage alloy tank 200 is also stopped, and the temperature in the hydrogen storage alloy tank 200 decreases. Then, depending on the temperature, the pressure in the hydrogen storage alloy tank 200 may also be reduced to a negative pressure, and the reverse flow from the main flow path 401 or the bypass flow path 405 toward the discharge port of the hydrogen storage alloy tank 200 may occur. Hydrogen gas flow occurs. Therefore, when a normal shut valve is used as the shut valve 402 provided in the main flow path 401 or the shut valve 412 provided in the bypass flow path 405, the shut flow is completely shut against the reverse flow described above. Therefore, the hydrogen gas remaining in the hydrogen gas flow path closer to the fuel cell 100 than the shut valves 402 and 412 passes through the shut valves 402 and 412 to the hydrogen gas flow path on the hydrogen storage alloy tank 200 side. The hydrogen gas leaks and flows into the hydrogen storage alloy tank 200. Since the hydrogen gas contains impurities such as nitrogen and water vapor, these impurities also flow into the hydrogen storage alloy tank 200 together, and the hydrogen storage in the hydrogen storage alloy tank 200 is caused by these impurities. The alloy may be affected.

  Therefore, in this embodiment, as the shut valves 402 and 412, shut valves having a backflow prevention function are used. Therefore, even if a reverse flow of hydrogen gas toward the hydrogen storage alloy tank 200 occurs when the fuel cell system is shut down, the shut valves 402 and 412 can be used by using such a shut valve with a backflow prevention function. Therefore, the hydrogen gas containing impurities does not leak into the hydrogen gas flow path on the hydrogen storage alloy tank 200 side, so that the hydrogen gas storage alloy in the hydrogen storage alloy tank 200 can be protected.

  The above is the operation when stopped. Next, the action at the time of abnormality will be described.

  First, when an abnormality such as failure of the pressure reducing valve 404 occurs, the pressure of the hydrogen gas supplied to the fuel cell 100 becomes abnormally high, and there is a risk that the fuel cell 100 will malfunction. Therefore, in this embodiment, a relief valve 416 is provided in the middle of the relief flow path 409 branched from the main flow path 401, and the pressure of the hydrogen gas in the main flow path 401 from the pressure reducing valve 404 to the fuel cell 100 is a predetermined value. When the pressure rises above, the relief valve 416 is opened and the hydrogen gas is discharged into the atmosphere outside the vehicle. At this time, it is preferable that the discharge port for the hydrogen gas is provided at a position where the hydrogen gas is discharged toward the road surface so that the discharged hydrogen gas does not collect in a certain place. This is because by providing at such a position, the discharged hydrogen is easily diffused.

  Next, when a vehicle collision occurs or a control system failure occurs, in the worst case, there is a risk of hydrogen leakage or the like. Therefore, in this embodiment, when a collision vibration or a control system failure is detected, the control unit 50 causes the shut valve 202 of the hydrogen storage alloy tank 200 and the shut valves 102 and 104 of the fuel cell 100 to be connected. It closes automatically and cuts off the supply of hydrogen gas to prevent hydrogen gas from leaking.

B. Second embodiment:
B-1. Configuration of the second embodiment:
FIG. 4 is a block diagram showing an in-vehicle fuel cell system as a second embodiment of the present invention. In the fuel cell system of the first embodiment, the hydrogen storage alloy tank 200 is used as a hydrogen gas supply source. However, in the fuel cell system of this embodiment, high-pressure hydrogen is used instead of the hydrogen storage alloy tank 200. A gas tank 300 is used.

  The high-pressure hydrogen gas tank 300 is filled with high-pressure hydrogen gas, and when a shut valve 302 attached to the root is opened, hydrogen gas having a pressure of about 20 to 35 MPa is released.

  Since the fuel cell 100 has the same configuration as that of the first embodiment, the description thereof is omitted.

  In addition, as shown in FIG. 4, the fuel cell system of the present embodiment includes a hydrogen gas flow path, an oxidizing gas flow path, and a control unit 50. The oxidizing gas flow path is the first embodiment. Since it is the same structure as an example, description is abbreviate | omitted.

  The hydrogen gas flow path includes a main flow path 401 extending from the discharge port of the high-pressure hydrogen gas tank 300 to the supply port of the fuel cell 100, and a circulation flow path 403 returning from the discharge port of the fuel cell 100 to the main flow path 401 via the pump 410. And a discharge flow path 407 for discharging impurities in the circulating hydrogen gas, and a relief flow path 409 for discharging hydrogen gas when the pressure is abnormal. In this embodiment, since the high-pressure hydrogen gas tank 300 is used as the hydrogen gas supply source, the high-pressure hydrogen gas can be released regardless of the temperature. Therefore, unlike the case of the hydrogen storage alloy tank 200, the bypass channel 405 is not provided because it is not necessary to draw out hydrogen gas at the time of low temperature start.

  In the main flow path 401, a shut valve 202 is disposed at the discharge port of the high-pressure hydrogen gas tank 300, and a decompression valve 418, a heat exchanger 420, a decompression valve 422, and a gas-liquid separator 424 are disposed in the middle of the flow path. A shut valve 102 is disposed at the supply port of the fuel cell 100. In the circulation channel 403, a shut valve 104 is disposed at the discharge port of the fuel cell 100, and a gas-liquid separator 406, a pump 410, and a check valve 426 are disposed in the middle of the channel. The point that the shut valve 414 is arranged in the discharge channel 407 and the relief valve 416 is arranged in the relief channel 409 is the same as in the case of the first embodiment.

  The control unit 50 inputs the detection result from the pressure sensor 400 and controls each of the valves 102, 104, 302, and 414, the pump 410, and the compressor 504. Note that control lines and the like are omitted for easy viewing of the drawing.

B-2. Operation of the second embodiment:
Now, the flow of hydrogen gas will be described in detail. Since the flow of the oxidizing gas is the same as that in the first embodiment, description thereof is omitted.

  The control unit 50 causes the shut valve 302 of the high-pressure hydrogen gas tank 300 and the shut valves 102 and 104 of the fuel cell 100 to be basically opened during operation of the fuel cell system, but closed when stopped.

  In addition, during normal operation, the shut valve 414 of the discharge channel 407 is closed by the control unit 50. The relief valve 416 is closed except in the case of abnormal pressure, as in the case of the first embodiment.

  During normal operation, as described above, when the control unit 50 opens the shut valve 302, hydrogen gas is released from the high-pressure hydrogen gas tank 300, and the released hydrogen gas passes through the main flow path 401 to the fuel cell 100. Supplied. The supplied hydrogen gas is used as the above-described electrochemical reaction in the fuel cell 100 and then discharged as a hydrogen off gas. The discharged hydrogen off gas is returned to the main flow path 401 through the circulation flow path 403 and supplied to the fuel cell 100 again. At this time, as in the case of the first embodiment, the pump 410 provided in the middle of the circulation flow path 403 is driven, so that the hydrogen off-gas passing through the circulation flow path 403 gains momentum and the main flow flow path 401. Sent out. Thus, during normal operation, hydrogen gas circulates through the main flow channel 401 and the circulation channel 403. A check valve 426 is provided between the connection point with the main flow path 401 and the pump 410 in the circulation flow path 403 so that the circulating hydrogen off-gas does not flow backward. ing.

  Further, the pressure of the hydrogen gas released from the high-pressure hydrogen gas tank 300 is about 20 to 35 MPa as described above, and is much higher than the case of the hydrogen storage alloy tank 200 in the first embodiment. If the high-pressure hydrogen gas is directly supplied to the fuel cell 100, the pressure is too high and the fuel cell 100 is broken. Therefore, in this embodiment, the number of stages of decompression is increased as compared with the first embodiment, and two decompression valves, a decompression valve 418 for primary decompression and a decompression valve 422 for secondary decompression, are connected to the main flow path 401. Provided in the middle, the high-pressure hydrogen gas is depressurized in two stages. Specifically, the pressure is reduced from about 20 to 35 MPa to about 0.8 to 1 MPa by the pressure reducing valve 418 for primary pressure reduction, and further from about 0.8 to 1 MPa by the pressure reducing valve 422 for secondary pressure reduction. The pressure is reduced to about 0.2 to 0.3 MPa.

  In addition, in this way, since the high-pressure hydrogen gas is reduced from about 20 to 35 MPa to about 0.8 to 1 MPa by the pressure reducing valve 418 for primary pressure reduction, the hydrogen gas rapidly expands by about 50 times, and the temperature Will drop sharply. When such a temperature-decreased hydrogen gas is supplied to the fuel cell 100 as it is, the temperature in the fuel cell 100 is also lowered, and sufficient catalytic activity cannot be obtained. Therefore, the electrochemical reaction does not proceed and the power generation is hindered. Therefore, in this embodiment, in order to warm the hydrogen gas whose temperature has decreased due to the expansion to some extent and supply it to the fuel cell 100 at an appropriate temperature, a pressure reducing valve 418 for primary pressure reduction and a pressure reducing valve 422 for secondary pressure reduction are provided. A heat exchanger 420 is disposed between the two. Although not shown, the heat exchanger 420 is supplied with cooling water heated by the fuel cell 100, and heat exchange is performed between the heated cooling water and hydrogen gas whose temperature has decreased. It is like that. Thus, the hydrogen gas whose temperature has been lowered passes through the heat exchanger 420, so that the temperature becomes a substantially appropriate temperature and can be supplied to the fuel cell 100. Accordingly, since a sufficient reaction temperature can be obtained in the fuel cell 100, an electrochemical reaction proceeds and an appropriate power generation operation can be performed.

  Further, as described above, since the hydrogen gas flowing through the main flow path 401 has a relatively low temperature, it is included in the hydrogen off gas when mixed with the hydrogen off gas circulated through the circulation flow path 403 and returned to the main flow path 401. There is a risk that the water that has been condensed will be condensed and supplied to the fuel cell 100 as a gas-liquid mixture. Therefore, in this embodiment, a gas-liquid separator 424 is provided between the connection point between the main flow path 401 and the circulation flow path 403 and the supply port of the fuel cell 100, and the gas-liquid separator 424 The water contained in the mixed hydrogen gas is separated into gas and liquid, the liquid is removed, and only the gas (water vapor) is supplied to the fuel cell 100 together with other gases. As a result, the fuel cell 100 is free from the risk of hindering the power generation operation.

  The above is the flow of hydrogen gas during normal operation. Next, the control at the time of starting will be described.

  When the fuel cell system stops operating, impurities such as nitrogen permeate and diffuse from the oxygen electrode side to the hydrogen electrode side through the electrolyte membrane in the fuel cell 100. Of course, the hydrogen gas flow path also contains impurities such as nitrogen. Therefore, at the time of starting the fuel cell system, it is necessary to remove impurities present in the hydrogen gas flow path and fill them with hydrogen gas so that the fuel cell 100 can appropriately generate power in a short time.

  As a method for removing impurities present in the hydrogen gas flow path at the time of startup, for example, a method of extruding impurities by flowing a purge gas such as an inert gas into the hydrogen gas flow path before flowing in the hydrogen gas can be considered. In such a method, since an inert gas cylinder must be stacked in the vehicle in order to flow the purge gas, an extra space is required and the weight is increased accordingly.

  Therefore, a method of extruding impurities by flowing hydrogen gas directly into the hydrogen gas flow path without flowing purge gas can be considered. However, in such a method, it takes a considerable amount of time for the hydrogen gas to push out impurities and the output voltage of the fuel cell to reach the desired voltage, and during that time, the fuel cell is discharged from the fuel cell in order to remove the pushed out impurities. When the generated gas is thrown outside, there is a problem that the gas may contain a high concentration of hydrogen.

  Therefore, in this embodiment, at the time of start-up, not only the hydrogen gas flows into the hydrogen gas flow path, but also the pump 410 for circulating the hydrogen gas is driven to generate a forced flow in the hydrogen gas flow path. The impurities present in the hydrogen gas flow path and the hydrogen gas flowing in are agitated and made uniform.

  FIG. 5 is a flowchart showing an example of control contents of the control unit 50 at the start of the fuel cell system of FIG.

  At the start of the fuel cell system, the controller 50 first opens the shut valve 202 of the hydrogen storage alloy tank 200 and the shut valves 102 and 104 of the fuel cell 100 from the closed state as shown in FIG. S202). Then, hydrogen gas is released from the high-pressure hydrogen gas tank 300, and the released hydrogen gas flows through the main flow channel 401. Next, the control unit 50 drives the pump 410 at a standard rotation to forcibly cause a flow in the circulation flow path 403 to move impurities present in the hydrogen gas flow path and flow into the impurities. When hydrogen gas is circulated and agitated, both become uniform at an early stage.

  For example, if the impurity present in the hydrogen gas flow path is atmospheric pressure (0.1 MPa), the hydrogen gas is reduced to 2 atmospheres (0, 2 MPa) and flowed, so that the atmospheric pressure is 2 atmospheres. In this state, the hydrogen gas is circulated and stirred to homogenize impurities and hydrogen gas.

  Thus, when the impurities and hydrogen gas are made uniform, hydrogen is equally supplied to each hydrogen electrode in the fuel cell 100, so that the open-circuit voltage of the fuel cell 100 immediately rises. When the control unit 50 senses this rise based on the detection result from the voltage sensor (not shown) (step S206), the control unit 50 sets the load (not shown) to the fuel cell 100 as “power generation OK”. ) Are connected (step S208). Thereafter, the control unit 50 opens the shut valve 414 (step S210), and gradually discharges the circulating gas (uniform impurities and hydrogen gas). Since hydrogen gas continues to flow from the high-pressure hydrogen gas tank 300, the circulating gas gradually increases the hydrogen concentration.

  After that, when a predetermined time has elapsed (step S212), the control unit 50 determines that the impurities present in the hydrogen gas flow passage have escaped to some extent, and the hydrogen concentration of the circulating hydrogen gas has become sufficient. Is closed (step S214). And it will be in a normal driving | running state.

  Thus, when starting the fuel cell system, hydrogen gas flows into the hydrogen gas flow path and the pump 410 can be driven to increase the output voltage of the fuel cell 100 to a desired voltage in a short time. . Further, since no purge gas is required, a purge gas cylinder is unnecessary, and space saving and weight reduction can be achieved. Furthermore, since high concentration hydrogen gas is not discharged, high safety can be ensured.

  In this embodiment, the operation of the shut valve 414 provided in the discharge flow path 407 and the relief valve 416 provided in the relief flow path 409 is the same as in the case of the first embodiment, and thus description thereof is omitted. To do.

C. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the scope of the invention.

  In the first and second embodiments described above, the gas-liquid separator 406 is provided in the circulation flow path 403. However, such a configuration has a hydrogen storage alloy tank 200 or a high-pressure hydrogen gas tank as a hydrogen gas supply source. Instead of 300, the present invention can also be applied to a fuel cell system using a reformer that reforms raw fuel to generate hydrogen gas.

  In the second embodiment described above, the gas-liquid separator 424 is provided in the main flow path 401. However, such a configuration can also be applied to the fuel cell system of the first embodiment. The present invention can also be applied to a fuel cell system using a reformer or the like as a hydrogen gas supply source.

  In the second embodiment, the heat exchanger 420 is provided between the pressure reducing valves 418 and 422. However, the heat exchanger 420 may be provided on the downstream side of the pressure reducing valve 422. In the fuel cell system of the first embodiment, since the pressure reducing valve 404 is used, such a heat exchanger may be provided on the downstream side of the pressure reducing valve 404 if necessary. .

  Further, in the second embodiment described above, the control as shown in FIG. 5 is performed at the start of the fuel cell system. However, such a control is also applied to the fuel cell system of the first embodiment. It can also be applied to a fuel cell system using a reformer or the like as a hydrogen gas supply source. However, when applied to the fuel cell system of the first embodiment, at the time of low temperature start, first, hydrogen gas is drawn from the hydrogen storage alloy tank 200 by the pump 410, and then the shut valves 402, 408, 412 are opened and closed. By switching the state, the remaining impurities and the extracted hydrogen gas are circulated by the pump 410 so as to be uniformized.

DESCRIPTION OF SYMBOLS 50 ... Control part 100 ... Fuel cell 102 ... Shut valve 104 ... Shut valve 200 ... Hydrogen storage alloy tank 202 ... Shut valve 300 ... High pressure hydrogen gas tank 302 ... Shut valve 400 ... Pressure sensor 401 ... Main flow path 402 ... Shut valve 403 ... Circulating flow path 404 ... Pressure reducing valve 404 ... Pressure reducing valve 405 ... Bypass flow path 406 ... Gas-liquid separator 407 ... Discharge flow path 408 ... Shut valve 409 ... Relief flow path 410 ... Pump 412 ... Shut valve 414 ... Shut valve 416 ... Relief Valve 418 ... Pressure reducing valve 420 ... Heat exchanger 422 ... Pressure reducing valve 424 ... Gas-liquid separator 426 ... Check valve 501 ... Oxidizing gas supply flow path 502 ... Air cleaner 503 ... Oxygen off gas discharge flow path 504 ... Compressor 506 ... Humidifier 5 8 ... gas-liquid separator 510 ... combustor 512 ... platinum catalyst 602 ... inlet 604 ... cylinder 606 ... outlet 610 ... gas flow channel 612 ... cock

Claims (8)

A hydrogen gas storage unit capable of releasing the stored hydrogen gas at a predetermined pressure; and a fuel cell that generates electric power upon receiving the supply of the hydrogen gas released from the hydrogen gas storage unit. An in-vehicle fuel cell system mounted on a vehicle,
A first flow path connecting the discharge port of the hydrogen gas storage unit and the supply port of the fuel cell, and supplying the hydrogen gas discharged from the hydrogen gas storage unit to the fuel cell; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A second channel extending toward the outside of the vehicle from a specific location located between the decompression unit and the fuel cell supply port in the first channel;
A relief valve disposed in the second flow path and capable of flowing and stopping gas by opening and closing;
With
The relief valve is opened when the pressure of the hydrogen gas existing in the flow path on the specific location side of the relief valve exceeds a reference pressure, and the hydrogen gas is removed from the first flow path through the first flow path. 2 to the outside through the flow path ,
The in- vehicle fuel cell system , wherein the discharge port of the second flow path is arranged so that the discharged hydrogen gas is directed to the road surface . A hydrogen gas supply unit for supplying hydrogen gas; and a fuel cell that receives the supply of the hydrogen gas delivered from the hydrogen gas supply unit to generate electric power and discharge the remaining hydrogen gas. An in-vehicle fuel cell system mounted on a vehicle,
A first flow path for connecting the supply port of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell with the hydrogen gas sent from the hydrogen gas supply unit; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A second channel extending toward the outside of the vehicle from a specific location located between the decompression unit and the fuel cell supply port in the first channel;
A relief valve disposed in the second flow path and capable of flowing and stopping gas by opening and closing;
A third flow path connecting the discharge port of the fuel cell and the first flow path, and flowing the hydrogen gas discharged from the fuel cell and returning it to the first flow path;
A gas-liquid separator that is disposed in the third flow path and separates the water contained in the hydrogen gas discharged from the fuel cell into a liquid and a gas, and removes only the liquid;
Equipped with a,
The relief valve is opened when the pressure of the hydrogen gas existing in the flow path on the specific location side of the relief valve exceeds a reference pressure, and the hydrogen gas is removed from the first flow path through the first flow path. 2 to the outside through the flow path,
The in- vehicle fuel cell system , wherein the discharge port of the second flow path is arranged so that the discharged hydrogen gas is directed to the road surface . A hydrogen gas supply unit for supplying hydrogen gas; and a fuel cell that receives the supply of the hydrogen gas delivered from the hydrogen gas supply unit to generate electric power and discharge the remaining hydrogen gas. An in-vehicle fuel cell system mounted on a vehicle,
A first flow path for connecting the supply port of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell with the hydrogen gas sent from the hydrogen gas supply unit; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A second channel extending toward the outside of the vehicle from a specific location located between the decompression unit and the fuel cell supply port in the first channel;
A relief valve disposed in the second flow path and capable of flowing and stopping gas by opening and closing;
A third flow path connecting the discharge port of the fuel cell and the first flow path, and flowing the hydrogen gas discharged from the fuel cell and returning it to the first flow path;
Arranged between the connecting portion of the first flow path to the third flow path and the supply port of the fuel cell, separating moisture contained in the hydrogen gas into a liquid and a gas; A gas-liquid separator that removes only the liquid;
Equipped with a,
The relief valve is opened when the pressure of the hydrogen gas existing in the flow path on the specific location side of the relief valve exceeds a reference pressure, and the hydrogen gas is removed from the first flow path through the first flow path. 2 to the outside through the flow path,
The in- vehicle fuel cell system , wherein the discharge port of the second flow path is arranged so that the discharged hydrogen gas is directed to the road surface . A hydrogen gas storage unit capable of releasing the stored hydrogen gas at a predetermined pressure; and a fuel cell that generates electric power upon receiving the supply of the hydrogen gas released from the hydrogen gas storage unit. An in-vehicle fuel cell system mounted on a vehicle,
A first flow path connecting the discharge port of the hydrogen gas storage unit and the supply port of the fuel cell, and supplying the hydrogen gas discharged from the hydrogen gas storage unit to the fuel cell; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A second channel extending toward the outside of the vehicle from a specific location located between the decompression unit and the fuel cell supply port in the first channel;
A relief valve disposed in the second flow path and capable of flowing and stopping gas by opening and closing;
A temperature raising unit that is disposed between the pressure reducing unit in the first flow path and the supply port of the fuel cell, and raises the temperature of the hydrogen gas flowing through the first flow path;
Equipped with a,
The relief valve is opened when the pressure of the hydrogen gas existing in the flow path on the specific location side of the relief valve exceeds a reference pressure, and the hydrogen gas is removed from the first flow path through the first flow path. 2 to the outside through the flow path,
The in- vehicle fuel cell system , wherein the discharge port of the second flow path is arranged so that the discharged hydrogen gas is directed to the road surface . A hydrogen gas supply unit for supplying hydrogen gas; and a fuel cell that receives the supply of the hydrogen gas delivered from the hydrogen gas supply unit to generate electric power and discharge the remaining hydrogen gas. An in-vehicle fuel cell system mounted on a vehicle,
A first flow path for connecting the supply port of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell with the hydrogen gas sent from the hydrogen gas supply unit; ,
At least one decompression unit disposed in the first flow path to reduce the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A second channel extending toward the outside of the vehicle from a specific location located between the decompression unit and the fuel cell supply port in the first channel;
A relief valve disposed in the second flow path and capable of flowing and stopping gas by opening and closing;
A third flow path connecting the discharge port of the fuel cell and the first flow path, and flowing the hydrogen gas discharged from the fuel cell and returning it to the first flow path;
Said third disposed in the flow path, said third flow path the hydrogen gas flowing through the flow toward the first flow path, a pump for circulating the hydrogen gas,
A control unit for controlling the hydrogen gas supply unit and the pump;
With
The control unit, when starting the fuel cell system, causes the hydrogen gas to be sent from the hydrogen gas supply unit and drives the pump to cause a flow in the flow path through which the hydrogen gas flows, Stir and homogenize the impurities present in the flow path and the hydrogen gas sent out ,
The relief valve is opened when the pressure of the hydrogen gas existing in the flow path on the specific location side of the relief valve exceeds a reference pressure, and the hydrogen gas is removed from the first flow path through the first flow path. 2 to the outside through the flow path,
The in- vehicle fuel cell system , wherein the discharge port of the second flow path is arranged so that the discharged hydrogen gas is directed to the road surface . A hydrogen gas supply unit for supplying hydrogen gas; and a fuel cell that receives the supply of the hydrogen gas delivered from the hydrogen gas supply unit to generate electric power and discharge the remaining hydrogen gas. , A control method for an in-vehicle fuel cell system mounted on a vehicle,
(A) a first connecting the outlet of the hydrogen gas supply unit and the supply port of the fuel cell and supplying the fuel cell by flowing the hydrogen gas delivered from the hydrogen gas supply unit; A flow path, at least one pressure-reducing section disposed in the first flow path and reducing the pressure of the hydrogen gas discharged from the hydrogen gas storage section, and the pressure-reducing section in the first flow path And a second flow path extending toward the outside of the vehicle from a specific location located between the fuel cell supply port and the fuel cell supply port, and disposed in the second flow path to flow or stop the gas by opening and closing A relief valve that can be connected to the fuel cell, a discharge port of the fuel cell and the first flow path, and a flow of the hydrogen gas discharged from the fuel cell to flow the first flow path a third flow path to return to, is disposed in the third flow path Flowed toward the hydrogen gas flowing through the third channel to the first channel, preparing a, a pump for circulating the hydrogen gas,
(B) at the time of starting the fuel cell system, sending the hydrogen gas from the hydrogen gas supply unit;
(C) driving the pump to cause a flow in the flow path through which the hydrogen gas flows, and stirring and homogenizing impurities present in the flow path and the delivered hydrogen gas;
(D) The discharge port of the second flow path is arranged so that the hydrogen gas to be discharged is directed to the road surface, and the pressure of the hydrogen gas existing in the flow path on the specific location side from the relief valve is And a step of opening the relief valve when a reference pressure is exceeded and discharging the hydrogen gas from the first flow path to the outside through the second flow path. Method. An in-vehicle fuel cell system mounted on a vehicle,
A hydrogen gas storage unit capable of releasing the stored hydrogen gas; and
A fuel cell that generates electric power by receiving the supply of the hydrogen gas released from the hydrogen gas storage unit;
A flow path for supplying the fuel cell by flowing the hydrogen gas released from the hydrogen gas storage unit;
At least one decompression unit disposed in the flow path and reducing the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
Relief that opens when the pressure of the hydrogen gas at a specific location between the pressure reducing unit and the fuel cell exceeds a reference pressure in the flow path, and discharges the hydrogen gas from the flow path to the outside. A valve,
An in- vehicle fuel cell system comprising: a discharge port arranged so that hydrogen gas discharged through the relief valve is directed toward a road surface . An in-vehicle fuel cell system mounted on a vehicle,
A hydrogen gas storage unit capable of releasing the stored hydrogen gas; and
A fuel cell that generates electric power by receiving the supply of the hydrogen gas released from the hydrogen gas storage unit;
A flow path for supplying the fuel cell by flowing the hydrogen gas released from the hydrogen gas storage unit;
At least one decompression unit disposed in the flow path and reducing the pressure of the hydrogen gas discharged from the hydrogen gas storage unit;
A temperature raising part that is disposed between the pressure reducing part and the fuel cell in the flow path and raises a temperature of the hydrogen gas flowing through the flow path;
Relief that opens when the pressure of the hydrogen gas at a specific location between the pressure reducing unit and the fuel cell exceeds a reference pressure in the flow path, and discharges the hydrogen gas from the flow path to the outside. A valve,
An in- vehicle fuel cell system comprising: a discharge port arranged so that hydrogen gas discharged through the relief valve is directed toward a road surface .

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