JP2006313664A - Fuel cell vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell vehicle in which the moisture in the exhaust air is exhausted without freezing. <P>SOLUTION: A first exhaust passage 21 that exhausts the exhaust air exhausted from the cathode 3 of the fuel cell 1 to the outside of the fuel cell vehicle, a second exhaust passage 22 that is shorter than the first exhaust passage 21, and a switching valve 4 that selectively switches the flow of the exhaust air to the first exhaust passage 21 or the second exhaust passage 22 are equipped, and in the case the internal passage resistance inside the first exhaust passage 21 becomes large, the exhaust air is exhausted from the second exhaust passage 22 to the outside of the fuel cell vehicle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell vehicle.

  2. Description of the Related Art Conventionally, in a fuel cell vehicle equipped with a polymer electrolyte fuel cell (hereinafter referred to as a fuel cell), for example, a fuel cell vehicle, exhaust gas such as exhaust oxidant gas discharged from the fuel cell is discharged to the outside of the fuel cell vehicle. When discharging, it is discharged from the rear of the fuel cell vehicle.

  However, when exhaust gas is discharged from the rear of the fuel cell vehicle, the length of the discharge path for discharging the exhaust gas from the fuel cell to the outside of the fuel cell vehicle becomes long. When the outside air temperature is low, for example, when operating below freezing, the temperature of the exhaust gas gradually decreases in the discharge path, water in the exhaust gas freezes, and ice may adhere to the inner wall of the discharge path. Therefore, there is a problem that the flow path resistance is increased and the flow of exhaust gas is deteriorated.

  The present invention was devised to solve such problems. For example, when operating under freezing, water is prevented from freezing in the discharge passage, and exhaust gas is discharged outside the fuel cell vehicle. With the goal.

  In the present invention, in a fuel cell vehicle equipped with a fuel cell that generates power using fuel gas and oxidant gas, a first discharge path for discharging gas discharged from the cathode of the fuel cell to the outside, and discharge from the cathode of the fuel cell. A second discharge path having a shorter length than the first discharge path, and a flow path resistance estimation means for estimating a flow path resistance of the gas discharged from the cathode in the first discharge path And a switching means for selectively switching the connection between the first discharge path or the second discharge path and the fuel cell. The switching means connects the fuel cell and the second discharge path when the flow path resistance is greater than a predetermined value.

  According to the present invention, when the gas discharged from the cathode of the fuel cell flows through the first discharge path, for example, when water contained in the exhaust oxidant gas is frozen and the flow path resistance may increase, the first Since the discharged oxidant gas is discharged from the fuel cell vehicle using the second discharge path that is shorter than the discharge path, for example, freezing in the first discharge path is prevented even when the temperature is below freezing, and the discharged oxidant gas is used as fuel. It can be discharged outside the battery vehicle.

  A schematic configuration of a fuel cell system mounted on a fuel cell vehicle according to a first embodiment of the present invention will be described with reference to FIG. In addition, although this embodiment demonstrates a fuel cell vehicle, it is not restricted to a fuel cell vehicle.

  In this embodiment, a fuel cell 1 that generates electric power by an electrochemical reaction between a fuel gas containing hydrogen and an oxidant gas containing oxygen, a circulation passage 10 for circulating exhaust hydrogen discharged from the anode 2 of the fuel cell 1, A discharge path 20 for discharging exhaust air discharged from the cathode 3 of the fuel cell 1 to the outside of the fuel cell vehicle and a discharge path 20 via a switching valve (switching means) 4 are discharged from the cathode 3. The exhaust gas discharged from the cathode 3 is connected to the first discharge passage 21 for discharging the exhaust gas from the rear of the fuel cell vehicle to the outside and the discharge passage 20 via the switching valve 4 and discharged from the lower portion of the fuel cell vehicle. And a second discharge path 22. Further, a connection path 11 that connects the circulation path 10 and the discharge path 20 is provided, and a purge valve (open / close valve) 5 is disposed in the connection path 11.

  The fuel cell 1 is a solid polymer type fuel cell having a solid polymer electrolyte membrane, and the operating temperature is relatively low at about 70 ° C., and the temperatures of exhaust fuel gas and exhaust oxidant gas discharged from the fuel cell 1 are engine It is lower than a vehicle equipped with an internal combustion engine. The fuel cell 1 is mounted on the front side of the fuel cell vehicle.

  The circulation flow path 10 includes a hydrogen circulation pump 6 that circulates discharged hydrogen and a hydrogen concentration sensor (fuel gas concentration detecting means) 7 that detects the hydrogen concentration in the discharged hydrogen discharged from the anode 2.

  The discharge path 20 includes a water recovery device 8 that condenses moisture in the discharged air and stores the condensed water.

  The water recovery device 8 has a gas-liquid separation device that separates moisture in the exhausted air, condenses the moisture separated thereby, and stores condensed water. The stored water is supplied to a humidifier (not shown) and used to humidify hydrogen or air supplied to the fuel cell 1. Further, when the amount of water stored in the water recovery device 8 exceeds the specified amount of water, the water is discharged from the drain valve (not shown) to the outside of the fuel cell vehicle. The exhaust air that has passed through the water recovery device 8 contains moisture that has not been separated by the gas-liquid separator.

  The switching valve 4 is provided in the vicinity of the fuel cell 1 and selectively switches the communication state between the discharge passage 20 and the first discharge passage 21 or the second discharge passage 22 according to the operating state of the fuel cell vehicle.

  The first discharge path 21 is a discharge path extending from the switching valve 4 to the rear of the fuel cell vehicle, and includes a temperature sensor (temperature detection means) 30 that detects the temperature of the first discharge path 21 in the middle thereof. The first discharge path 21 discharges exhaust air discharged from the cathode 3 and discharged hydrogen when a large amount of impure gas such as nitrogen is mixed into the discharged hydrogen circulated by the circulation flow path 10 from the rear of the fuel cell vehicle to the outside. Discharge. For example, a water repellent is applied to the inner wall of the first discharge passage 21 so that water contained in the exhaust gas does not easily adhere to the inner wall. Further, for example, the outer wall of the first discharge path 21 is covered with a heat insulating member and a heat insulating material in order to prevent water from freezing when the temperature is below freezing. It is desirable to use a member having low thermal conductivity for the first discharge path 21. Here, exhaust air or the like is discharged from the rear of the fuel cell vehicle to the outside of the fuel cell vehicle, but may be discharged from the lateral direction of the fuel cell vehicle.

  The second discharge path 22 is a discharge path whose opening is positioned below the switching valve 4 in the vertical direction and extends downward from the switching valve 4 in the vertical direction. In other words, the second discharge path 22 is a discharge path located on the front side of the fuel cell vehicle and having an opening facing the ground. Therefore, even when the moisture contained in the exhaust air is liquefied, the water can be quickly discharged to the outside of the fuel cell vehicle by gravity. In addition, the second discharge path 22 is shorter than the first discharge path 21 and discharges the exhaust air discharged from the cathode 3 to the outside of the fuel cell vehicle in a shorter time than when the first discharge path 21 is used. can do. Therefore, when the air temperature is low, the exhaust air is discharged using the second discharge path 22, so that the freezing of water inside the fuel cell vehicle can be suppressed. Similarly to the first discharge path 21, the second discharge path 22 performs water repellent treatment on the inner wall, and covers the outer wall with a heat insulating member, a heat insulating material, and the like. The second discharge path 22 is limited to a shape in which the opening is positioned below the switching valve 4 in the vertical direction and water can be discharged to the outside of the fuel cell vehicle by gravity, and extends downward in the vertical direction. There is nothing. It is desirable to use a member having low thermal conductivity for the second discharge path 22.

  In addition, a controller 40 that switches the communication state of the first discharge path 21 or the second discharge path 22 and the discharge path 20 by the switching valve 4 according to the temperature detected by the temperature sensor 30 and controls the opening and closing of the purge valve 5 is provided.

  With the above configuration, the exhaust air discharged from the cathode 3 is discharged from the first discharge path 21 or the second discharge path 22 to the outside of the fuel cell vehicle by the switching valve 4.

  Next, control of the switching valve 4 and the purge valve 5 by the controller 40 will be described using the flowchart of FIG.

  In step S100, the temperature sensor 30 detects the temperature T of the first discharge path 21. Then, the temperature T is compared with the predetermined temperature T1, and if the temperature T is higher than the predetermined temperature T1, the process proceeds to step S101. If the temperature T is lower than the predetermined temperature T1, the process proceeds to step S106. The predetermined temperature T1 is a temperature at which water contained in the discharged air is frozen in the first discharge passage 21 when the discharge air discharged from the cathode 3 is introduced into the first discharge passage 21, and is previously determined by an experiment or the like. This is the temperature to be set (step S100 constitutes a channel resistance estimating means).

  In step S101, since the temperature T is higher than the predetermined temperature T1, the discharge valve 20 and the first discharge passage 21 are communicated by the switching valve 4. When the temperature T is higher than the predetermined temperature T1, the moisture in the exhaust air does not freeze in the first discharge path 21, and therefore the exhaust air is discharged from the rear of the fuel cell vehicle using the first discharge path 21.

  The predetermined temperature T1 may be a general temperature at which the driver uses cooling. As a result, when cooling is used, exhaust air is discharged from the rear of the fuel cell vehicle using the first discharge path 21, so that the inside of the cabin is prevented from being warmed by the exhaust air, and the burden of air conditioning can be reduced. it can.

  In step S <b> 102, the hydrogen concentration d in the discharged hydrogen circulating through the anode 2 is detected by the hydrogen concentration sensor 7. If the hydrogen concentration d is lower than the predetermined concentration d1, the process proceeds to step S103. The predetermined concentration d1 is a concentration set in advance, and is a hydrogen concentration that can maintain the power generation efficiency in the fuel cell 1 sufficiently high.

  In step S103, the hydrogen concentration d is lower than the predetermined concentration d1, that is, a large amount of impure gas is mixed in the discharged hydrogen, so the purge valve 5 is opened and the discharged hydrogen is discharged outside the fuel cell vehicle using the first discharge passage 21. To discharge.

  In step S104, the hydrogen concentration d in the discharged hydrogen is detected by the hydrogen concentration sensor 7. Then, the detected hydrogen concentration d is compared with the predetermined concentration d2, and when the hydrogen concentration d becomes higher than the predetermined concentration d2, the process proceeds to step S105. The predetermined density d2 is higher than the predetermined density d1 in step S102. The predetermined density d2 may be equal to the predetermined density d1.

  In step S <b> 105, the purge valve 5 is closed and the discharged hydrogen discharged from the anode 2 is circulated to the anode 2 through the circulation channel 10.

  By the control from step S102 to step S105, when the hydrogen concentration in the discharged hydrogen is low, the discharged hydrogen is discharged outside the fuel cell vehicle using the first discharge path 21. Since the discharged hydrogen is discharged to the outside of the fuel cell vehicle through the first discharge passage 21, it is possible to prevent the fuel cell vehicle from being deteriorated due to heat mixed with the inside of the vehicle body and generated by reaction with oxygen.

  On the other hand, in step S106, since the temperature T is lower than the predetermined temperature T1, the discharge path 20 and the second discharge path 22 are communicated by the switching valve 4. If the temperature T is lower than the predetermined temperature T1, the water in the exhaust air may freeze in the first discharge passage 21, so that the switching valve 4 and the outside of the fuel cell vehicle are located outside the first discharge passage 21. The discharged air is discharged using the second discharge path 22 having a short length. This can prevent freezing of water in the exhaust air. Further, since the discharged air is discharged from the second discharge path 22 located on the front side of the fuel cell vehicle, the fuel cell vehicle can be warmed by the discharged air from the lower surface side at a low temperature.

  In step S107, the hydrogen concentration sensor 7 detects the hydrogen concentration d in the discharged hydrogen circulating through the anode 2. If the hydrogen concentration d is lower than the predetermined concentration d1, the process proceeds to step S108. When the hydrogen concentration d is higher than the predetermined concentration d1, this control is terminated.

  In step S108, the switching valve 4 causes the exhaust pipe 20 and the first discharge path 21 to communicate with each other, and the purge valve 5 is opened. As a result, the discharged hydrogen having a reduced hydrogen concentration d is discharged outside the fuel cell vehicle using the first discharge path 21.

  Since the second discharge path 22 is provided on the front side of the fuel cell vehicle, when the discharged hydrogen is discharged from the second discharge path 22 to the outside of the fuel cell vehicle, a small amount of hydrogen contained in the discharged hydrogen is converted into the fuel cell vehicle. The fuel cell vehicle may deteriorate due to reaction with oxygen in the air and heat generation. Therefore, in this embodiment, when discharging the discharged hydrogen to the outside of the fuel cell vehicle, the deterioration of the fuel cell vehicle due to heat generation or the like is prevented by discharging from the rear of the fuel cell vehicle using the first discharge path 21. be able to.

  Further, in this case, the discharged hydrogen is discharged from the anode 2 and the discharged air is discharged from the cathode 3, so that the pressure is increased in the first discharge path 21 and the flow velocity is increased. For this reason, the temperature of moisture in the exhaust air becomes low and the exhaust hydrogen or the exhaust air can be discharged outside the fuel cell vehicle before freezing. Further, when ice is attached to the inner wall of the first discharge path 21, the attached ice can be discharged to the outside of the fuel cell vehicle.

  In step S109, the hydrogen concentration sensor 7 detects the hydrogen concentration d in the discharged hydrogen, and when the hydrogen concentration d becomes higher than the predetermined concentration d2, the process proceeds to step S110.

  In step S110, since the hydrogen concentration d is higher than the predetermined concentration d2, the switching valve 4 causes the discharge passage 20 and the second discharge passage 22 to communicate with each other and the purge valve 5 is closed. As a result, the discharged hydrogen discharged from the anode 2 is circulated by the circulation flow path 10.

  By the above control, when the temperature T of the first discharge path 21 is higher than the predetermined temperature T1, the exhaust air discharged from the cathode 3 is discharged from the rear of the fuel cell vehicle using the first discharge path 21, When the temperature T is lower than the predetermined temperature T <b> 1, the discharged air is discharged using the second discharge path 22 that is shorter than the first discharge path 21. Thereby, in the fuel cell vehicle, it is possible to prevent the water from being frozen in the discharge path and to discharge the discharged air.

  Further, when the hydrogen concentration in the discharged hydrogen becomes low, the discharged hydrogen is mixed into the fuel cell vehicle by discharging from the rear of the fuel cell vehicle using the first discharge path 21. Deterioration can be suppressed.

  Note that when the load required for the fuel cell 1 is large, that is, when the moisture contained in the exhaust air is large, the exhaust air may be discharged from the second discharge path 22 by the switching valve 4. When the amount of water contained in the discharge air is large, the discharge air is discharged from the second discharge path 22 that is shorter than the first discharge path 21 to prevent water from freezing in the discharge path. Can do.

  In addition, a heating device that heats the switching valve 4, the first discharge path 21, and the second discharge path 22 may be provided to prevent the switching valve 4 and the like from being frozen.

  The effect of 1st Embodiment of this invention is demonstrated.

  In this embodiment, a first discharge path 21 that discharges exhaust air discharged from the cathode 3 of the fuel cell 1 to the outside of the fuel cell vehicle, and a second discharge path 222 that is shorter than the first discharge path 21. Is provided. In addition, a switching valve 4 is provided that selectively switches the flow of exhaust air exhausted from the cathode 3 to the first exhaust path 21 or the second exhaust path 22. When the temperature T of the first discharge path 21 is lower than the predetermined temperature T1, the discharged air is discharged from the second discharge path 22 to the outside of the fuel cell vehicle without freezing water in the discharged air. Can be discharged.

  When the first discharge path 21 is extended to the rear part of the fuel cell vehicle, the first discharge path 22 is provided on the lower surface of the fuel cell vehicle, and the temperature T of the first discharge path 21 is higher than the predetermined temperature T1, By discharging the exhaust air to the outside of the fuel cell vehicle using the first discharge path 21, it is possible to prevent the fuel cell vehicle from being warmed by the exhaust air.

  By arranging the second discharge path 22 downward in the vertical direction, the water condensed in the second discharge path 22 can be discharged to the outside of the fuel cell vehicle by gravity, and the water in the second discharge path 22 can be discharged. Can be prevented from freezing. The second discharge pipe 22 is provided on the front side of the fuel cell vehicle, and the fuel cell vehicle can be warmed from the lower surface side by the exhaust air discharged from the second discharge path 22.

  When impure gas is mixed into the exhausted hydrogen circulating through the anode 2 and the hydrogen concentration d in the exhausted hydrogen is lower than the predetermined concentration d1, the purge valve 5 is opened, and the switching valve 4 and the first discharge channel 20 are connected to the first hydrogen. The discharged hydrogen is discharged from the first discharge channel 21 through the discharge channel 21. By discharging the discharged hydrogen from the first discharge passage 21, it is possible to prevent the discharged hydrogen from being mixed into the fuel cell vehicle, and to prevent deterioration of the fuel cell vehicle due to heat generated by reaction with oxygen. Can do.

  Next, a schematic configuration of the fuel cell system mounted on the fuel cell vehicle according to the second embodiment of the present invention will be described with reference to FIG. This embodiment includes a pressure sensor 31 in the discharge path 20. In addition, a current sensor 32 that detects the power generation state of the fuel cell 1 is provided. Since other configurations are the same as those of the first embodiment, description thereof is omitted here.

  The control operation of the switching valve 4 and the purge valve 5 by the controller 40 will be described with reference to the flowchart of FIG. Immediately after starting the fuel cell vehicle, the switching valve 4 allows the discharge path 20 and the first discharge path 21 to communicate with each other.

  In step S200, it is determined whether or not the flag f set in the previous control is zero. If the flag f set in the previous control is 0, that is, if it is determined that the pressure P detected by the pressure sensor 31 in step S201 described later in the previous control is greater than the predetermined pressure P1, or a step described later. If it is determined in step S214 that the temperature T is higher than the predetermined temperature T1, the process proceeds to step S201. If the flag f set in the previous control is 1, that is, the temperature T is set in step S214 described later in the previous control. If it is determined that the temperature is lower than the predetermined temperature T1, the process proceeds to step S209. In the first control that starts the fuel cell vehicle, the process proceeds to step S201.

  In step S201, the current sensor 32 detects the current density I generated by the fuel cell 1.

  In step S202, the pressure P in the discharge path 20 is detected by the pressure sensor 31, and the pressure difference between the outlet pressure of the first discharge path 21 (here, atmospheric pressure), that is, the pressure loss in the first discharge path 21. ΔP is calculated. Further, the predetermined pressure loss ΔP1 in the first discharge path 21 when ice is not attached to the inner wall of the first discharge path 21 is calculated according to the current density I detected in step S201 from the map shown in FIG. FIG. 5 is a map created in advance by experiments or the like. The predetermined pressure loss ΔP1 may have a fluctuation range. That is, the predetermined pressure loss ΔP <b> 1 may be a pressure loss in a case where some ice adheres to the inner wall of the first discharge path 21.

  In step S203, the pressure loss ΔP is compared with the predetermined pressure loss ΔP1. When the pressure loss ΔP is larger than the predetermined pressure loss ΔP1, that is, when the current pressure loss ΔP in the first discharge path 21 is larger than the predetermined pressure loss ΔP1 when ice does not adhere to the first discharge path 21. In step S209, if the pressure loss ΔP is smaller than the predetermined pressure loss ΔP1, the process proceeds to step S204 (step S200 to step S203 constitute flow path resistance estimation means).

  In step S204, the hydrogen concentration sensor 7 detects the hydrogen concentration d in the discharged hydrogen circulating through the anode 2. If the hydrogen concentration d is lower than the predetermined concentration d1, the process proceeds to step S205. If the hydrogen concentration d is higher than the predetermined concentration d1, the process proceeds to step S208. The predetermined concentration d1 is a concentration that is set in advance and is a hydrogen concentration that can sufficiently generate power in the fuel cell 1.

  In step S205, the hydrogen concentration d is lower than the predetermined concentration d1, that is, impure gas is mixed in the discharged hydrogen, so the purge valve 5 is opened and the discharged hydrogen is discharged to the outside of the fuel cell vehicle using the first discharge passage 21. Discharge.

  In step S206, the hydrogen concentration sensor 7 detects the hydrogen concentration d in the discharged hydrogen. Then, the detected hydrogen concentration d is compared with the predetermined concentration d2, and when the hydrogen concentration d becomes higher than the predetermined concentration d2, the process proceeds to step S207. The predetermined density d2 is higher than the predetermined density d1 in step S204. The predetermined density d2 may be equal to the predetermined density d1.

  In step S207, since the hydrogen concentration d has become higher than the predetermined concentration d2, the purge valve 5 is closed, and the discharged hydrogen discharged from the anode 2 is circulated to the anode 2 through the circulation passage 10. Thereafter, the process proceeds to step S208.

  By the control from step S204 to step S207, when the hydrogen concentration in the discharged hydrogen is low, the discharged hydrogen is discharged to the outside of the fuel cell vehicle using the first discharge path 21. Since the discharged hydrogen is discharged to the outside of the fuel cell vehicle through the first discharge passage 21, it is possible to prevent hydrogen from entering the inside of the vehicle body and deterioration of the fuel cell vehicle due to heat generated by reaction with oxygen.

  In step S208, the flag f is set to 0, and this control is finished.

  On the other hand, if it is determined in step S200 that the flag f set in the previous control is 1, or if the pressure loss ΔP is larger than the predetermined pressure loss ΔP1 in step S203, the process proceeds to step S209. In step S209, the discharge path 20 and the second discharge path 22 are communicated by the switching valve 4. If it is determined in the previous control that the temperature T of the first discharge path 21 is lower than the predetermined temperature T1, or if the pressure loss ΔP is larger than the predetermined pressure loss ΔP1 in step S203, the discharge path 20 and the second discharge path By communicating with 22, water freezing in the first discharge path 21 can be prevented. Further, the fuel cell vehicle can be warmed by the exhaust air.

  In step S210, the hydrogen concentration sensor 7 detects the hydrogen concentration d in the discharged hydrogen circulating through the anode 2. If the hydrogen concentration d is lower than the predetermined concentration d1, the process proceeds to step S211. If the hydrogen concentration d is higher than the predetermined concentration d1, the process proceeds to step S214.

  In step S211, the switching valve 4 causes the exhaust pipe 20 and the first discharge path 21 to communicate with each other, and the purge valve 5 is opened. As a result, the discharged hydrogen having a reduced hydrogen concentration d is discharged outside the fuel cell vehicle using the first discharge path 21. When discharging the discharged hydrogen to the outside of the fuel cell vehicle, the first discharge passage 21 can be used to prevent entry of the discharged hydrogen into the fuel cell vehicle and prevent deterioration of the fuel cell vehicle. it can. Further, when ice is attached to the inner wall of the first discharge passage 21, the ice attached to the inner wall can be discharged to the outside of the fuel cell vehicle by discharged hydrogen and discharged air.

  In Step S212, the hydrogen concentration d in the discharged hydrogen is detected by the hydrogen concentration sensor 7, and when the hydrogen concentration d becomes higher than the predetermined concentration d2, the process proceeds to Step S213.

  In step S213, since the hydrogen concentration d is higher than the predetermined concentration d2, the purge valve 5 is closed. As a result, the discharged hydrogen discharged from the anode 2 is circulated by the circulation flow path 10.

  By the control from step S210 to step S213, when the hydrogen concentration in the discharged hydrogen is low, the discharged hydrogen is discharged to the outside of the fuel cell vehicle using the first discharge path 21. Since the discharged hydrogen is discharged to the outside of the fuel cell vehicle through the first discharge passage 21, it is possible to prevent the deterioration of the fuel cell vehicle due to the heat generated by the reaction with oxygen by mixing the discharged hydrogen into the fuel cell vehicle. it can.

  In step S214, the temperature T is detected by the temperature sensor 30 and compared with a predetermined temperature T1. If the temperature T is higher than the predetermined temperature T1, the process proceeds to step S215. If the temperature T is lower than the predetermined temperature T1, the process proceeds to step S217.

  In step S215, the switching valve 4 causes the discharge path 20 and the first discharge path 21 to communicate with each other.

  In step S216, the flag f is set to 0 and this control is terminated.

  In step S217, the switching valve 4 causes the discharge path 20 and the second discharge path 22 to communicate with each other.

  In step S218, the flag f is set to 1 and this control is finished.

  In the control from step S214 to step S218, the communication state between the discharge path 20 and the first discharge path 21 or the second discharge path 22 is controlled based on the temperature T detected by the temperature sensor 30, and the next control step S200 is performed. The flag f to be read is set.

  With the above control, the pressure loss ΔP of the first discharge path 21 is detected based on the pressure detected by the pressure sensor 30 when ice adheres to the inner wall of the first discharge path 21, and the pressure loss ΔP is a predetermined predetermined pressure loss. When it is larger than ΔP1, the second exhaust path 22 is used to exhaust the exhaust air to the outside of the fuel cell vehicle.

  The effect of 2nd Embodiment of this invention is demonstrated.

  In this embodiment, the pressure loss ΔP in the first discharge path 21 is calculated based on the pressure detected by the pressure sensor 30 in addition to the effects of the first embodiment, and the first discharge path by the switching valve 4 is calculated based on the pressure loss ΔP. By switching the communication state of the discharge path 20 with the 21 or the second discharge path 22, it is possible to accurately determine the adhesion of ice or the like in the first discharge path 21.

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

  It can be used for a vehicle equipped with a fuel cell.

It is a schematic explanatory drawing of the fuel cell system of 1st Embodiment of this invention. It is a flowchart which shows the control by the controller of 1st Embodiment of this invention. It is a schematic explanatory drawing of the fuel cell system of 2nd Embodiment of this invention. It is a flowchart which shows the control by the controller of 2nd Embodiment of this invention. It is a map which shows the relationship between the current density and pressure loss of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Anode 3 Cathode 4 Switching valve (switching means)
5 Purge valve (open / close valve)
7 Hydrogen concentration sensor (Fuel gas concentration detection means)
DESCRIPTION OF SYMBOLS 10 Circulation flow path 11 Connection path 20 Discharge path 21 1st discharge path 22 2nd discharge path 30 Temperature sensor (temperature detection means)
31 Pressure sensor (pressure detection means)
40 controller

Claims (10)

In a fuel cell vehicle equipped with a fuel cell that generates power using fuel gas and oxidant gas,
A first discharge path for discharging gas discharged from the cathode of the fuel cell to the outside;
A gas discharged from the cathode of the fuel cell to the outside, a second discharge path shorter in length than the first discharge path;
Channel resistance estimating means for estimating channel resistance of gas discharged from the cathode in the first discharge channel;
Switching means for selectively switching the connection between the first discharge path or the second discharge path and the fuel cell;
The switching means connects the fuel cell and the second discharge path when the flow path resistance is larger than a predetermined value. The first discharge path extends to the rear of the vehicle body,
The fuel cell vehicle according to claim 1, wherein the second discharge path is provided on a lower surface of the vehicle body.   3. The fuel cell vehicle according to claim 1, wherein the second discharge path has an opening positioned vertically below the switching unit. 4. The flow path resistance estimation means includes temperature detection means for detecting the temperature of the first discharge path,
4. The switch according to claim 1, wherein when the temperature of the first discharge path is lower than a predetermined temperature, the switching unit connects the fuel cell and the second discharge path. The fuel cell vehicle described. The flow path resistance estimation means includes a pressure loss calculation means for calculating a pressure loss in the first discharge path,
The fuel according to any one of claims 1 to 3, wherein the switching means connects the fuel cell and the second discharge path when the pressure loss is larger than a predetermined pressure loss. Battery powered vehicle.   6. The fuel cell vehicle according to claim 5, wherein the pressure loss calculating means includes a pressure sensor that detects a pressure upstream in a flow direction of the gas discharged from the cathode. A circulation flow path for circulating the exhaust fuel gas discharged from the fuel cell to the fuel cell;
Fuel gas concentration detection means for detecting the fuel gas concentration in the exhaust fuel gas flowing through the circulation flow path;
A connection path connecting the circulation path and the first discharge path;
An on-off valve disposed in the connection path,
7. The exhaust gas according to claim 1, wherein when the fuel gas concentration in the exhaust fuel gas becomes lower than a predetermined concentration, the on-off valve is opened and the exhaust fuel gas is discharged from the first discharge path. The fuel cell vehicle according to one. Water amount detecting means for detecting the amount of water contained in the gas discharged from the cathode,
The fuel cell vehicle according to any one of claims 1 to 7, wherein the fuel cell and the second discharge path are connected when the amount of water is greater than a predetermined amount.   9. The fuel cell vehicle according to claim 8, wherein the water amount detection means is estimated from a load of the fuel cell.   The fuel cell vehicle according to any one of claims 1 to 9, wherein inner wall surfaces of the first discharge path and the second discharge path have water repellency.

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