JP2007280613A - Exhaust system for fuel cell vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust system capable of suppressing occurrence of abnormal noise due to water accumulating in the system and exhausting downstream from a top of a slanted part at the time of a large exhaust flow. <P>SOLUTION: The exhaust system 10 stores water inside it in a bypass channel 30 when an exhaust flow is small to medium, and, when an exhaust flow is large, a valve 40 squeezes an exhaust flow flowing in a main channel 20 to augment a bypass flow, whereby, water stored in the bypass channel 30 is pushed out of it and exhausted downstream from the top 18 of the slanted part 17. With this, when an exhaust flow is medium, the bypass channel 30 retains the water, so that the water is prevented from striking waves to make abnormal noise at the slanted part 17, and the water stored in the bypass channel 30 can be exhausted downstream from the slanted part 17. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exhaust device provided in a fuel cell vehicle, and more particularly to a structure for discharging condensed water of moisture contained in exhaust gas to the outside of the exhaust device.

  In the fuel cell, the fuel gas supplied to the anode electrode and the oxidizing gas supplied to the cathode electrode react at the electrolyte membrane, and at the same time, moisture is generated. The generated water is discharged from an exhaust device coupled to the fuel cell together with the fuel gas and the oxidizing gas that have not been used for the reaction.

  A fuel cell exhaust system mounted on a vehicle exhausts the sound absorbed by the silencer, the exhaust pipe (front pipe) connecting the silencer and the fuel cell unit, and the sound absorbed by the silencer to the outside air. It consists of an exhaust pipe (tail pipe) and the like. The exhaust pipe normally extends in the front-rear direction of the vehicle along the lower surface of the underbody of the vehicle. The exhaust pipe has a bent portion in the vertical direction in order to avoid vehicle components such as the rear wheel suspension arm, fuel tank or auxiliary tire, or to satisfy the layout requirements required from the departure angle, etc. ing.

  When moisture contained in the exhaust gas condenses in such an exhaust device, water may accumulate in a portion of the exhaust pipe that is low in the vertical direction. The water accumulated in the exhaust device is adsorbed by the sound absorbing material of the silencer and deteriorates the noise reduction performance, and causes various problems such as generating an abnormal sound by hitting a wave when flowing in the exhaust device.

  In order to prevent this, in the exhaust device described in Patent Document 1 below, a hole communicating with the outside of the exhaust pipe is provided in the middle of the exhaust pipe constituting the exhaust device, and water is discharged from the exhaust device to the outside. By setting such a hole for discharging water on the upstream side (fuel cell side) from the silencer (muffler), the sound absorbing material of the silencer is prevented from containing water.

JP 2005-73463 A

  However, the exhaust device described in Patent Document 1 has a problem in that exhaust noise leaks from a hole for discharging water, and exhaust noise increases. For this reason, the exhaust device is required to have a technique for satisfactorily discharging the water in the exhaust device from the rear end of the exhaust device without providing a hole for discharging water.

  By the way, as described above, the exhaust pipe of the exhaust device generally has a portion bent in the vertical direction, and therefore a portion inclined downward in the vertical direction toward the downstream (hereinafter referred to as an inclined portion). ) Often collects water upstream. In particular, the tail pipe has its rear end set vertically above the silencer due to the layout requirements of the rear part of the vehicle, so that a steep inclined part is formed upstream from the rear end of the tail pipe. In many cases, water accumulates on the upstream side of the inclined portion.

  If the exhaust flow rate suddenly increases in the state where water is accumulated upstream from the inclined part, the water flows up the inclined part due to the pressure of the exhaust flow, and is discharged further downstream beyond the top of the inclined part. The However, when water is accumulated and the exhaust flow rate is medium, the water goes up the slope partway, but cannot reach the top of the slope part. There was a problem that an abnormal noise was generated by hitting a wave by the pressure of the exhaust flow.

  Therefore, the present invention provides an exhaust device that can suppress abnormal noise generated when water accumulated in the exhaust device hits a wave.

  In the exhaust device for a fuel cell vehicle according to the present invention, the exhaust passage through which the exhaust from the fuel cell flows is provided in a vertically downward direction from the main passage, including a main passage including an inclined portion inclined vertically upward toward the downstream. The water from the main passage can be stored, and the exhaust flow flowing through the main passage is branched from the upstream side of the inclined portion, and upstream of the highest vertical position of the inclined portion extending obliquely upward with respect to the vertical direction. And a bypass flow increasing means for increasing a bypass flow that is an exhaust flow flowing through the bypass passage when the exhaust gas flow rate is large. When the bypass flow increasing means increases the bypass flow, the water stored in the bypass passage is pushed out to the inclined portion side by the bypass flow and discharged downstream from the top of the inclined portion. As a result, when the exhaust flow rate is medium, by holding water in the bypass passage, it is possible to prevent the water from swelling in the inclined portion and generating abnormal noise, and the water stored in the bypass passage is When the exhaust flow rate is large, it can be discharged downstream from the inclined portion at a time.

  Preferably, the bypass flow increasing means includes a valve that is provided in a portion of the main passage that is parallel to the bypass passage and that is controlled so as to restrict the exhaust flow flowing through the main passage when the exhaust flow rate reaches a predetermined threshold value. By restricting the exhaust flow flowing through the main passage by the valve, the bypass flow can be rapidly increased, and the water stored in the bypass passage can be discharged instantaneously.

  Preferably, the valve is controlled by determining whether or not the exhaust gas flow rate has reached a predetermined threshold based on a parameter relating to a gas discharge amount from a blower that supplies oxidizing gas to the fuel cell. As this parameter, for example, the flow value of the gas flow sensor, the pressure value of the gas pressure sensor, or the rotational speed of the blower is suitable.

  Preferably, the bypass flow increasing means is a guide member that is provided in the vicinity of the inlet of the bypass passage and guides the exhaust flow of the main passage to the bypass passage.

  Preferably, the portion where the bypass passage merges with the main passage is set in the middle of the inclined portion.

  According to the present invention, since moisture is discharged downstream from the top of the inclined portion or is stored in the bypass passage, the generation of abnormal noise can be reduced.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, an outline of a fuel cell system to which the exhaust device of the present embodiment is applied will be described with reference to FIGS. 1 and 2. FIG. 1 shows a system configuration diagram of the fuel cell system, and FIG. 2 shows a side view of the exhaust device. In the figure, the left side of the fuel cell vehicle on which the fuel cell system is mounted, the rear of the vehicle, and the vertical upper side are indicated by arrows X, Y, and Z, respectively, and the direction in which exhaust flows, that is, the downstream side is indicated by arrow A. ing.

  The fuel cell system 80 includes a fuel cell 82, a hydrogen tank 84 that supplies hydrogen gas to the fuel cell 82, a blower 86 that supplies oxidizing gas to the fuel cell 82, and an exhaust system 88 that exhausts exhaust from the fuel cell 82 (FIG. 1). (Indicated by a two-dot chain line).

  The hydrogen tank 84 is connected to the fuel cell 82 via the fuel gas supply path 85, and the flow rate of the hydrogen gas (fuel gas) stored in the hydrogen tank 84 is adjusted by the regulator 90, and the control valve 92 is turned on. Then, the fuel cell 82 is supplied. On the other hand, the blower 86 is connected to the fuel cell 82 via the oxidizing gas supply path 87 and supplies air (oxidizing gas) to the fuel cell 82. In the fuel cell 82, when the supplied hydrogen gas reacts with air, electric energy is generated and moisture is generated at the same time.

  Hydrogen gas that has not been used for the reaction (hereinafter referred to as anode exhaust gas) and air that has not been used for the reaction (hereinafter referred to as cathode exhaust gas) are discharged from the fuel cell 82 to the exhaust system 88. The anode exhaust gas and the cathode exhaust gas contain moisture generated by the reaction. The cathode exhaust gas flows into the diluter 94 through the cathode exhaust gas passage 93, while the anode exhaust gas passes through the anode exhaust gas passage 95 and flows into the diluter 94 through the circulation pump 96 and the purge valve 98. The anode exhaust gas and the cathode exhaust gas are merged by the diluter 94 to become moisture-containing exhaust gas and flow into the exhaust device 10.

  As shown in FIG. 1, the exhaust device 10 constitutes a part of the exhaust system 88 of the fuel cell system 80, and after absorbing the exhaust flowing in from the diluter 94 of the fuel cell system 80, Exhaust to the open air. The exhaust device 10 includes a silencer 14 for absorbing exhaust sound, a front pipe 12 that connects the silencer 14 and the diluter 94, a tail pipe 16 that exhausts exhaust gas absorbed by the silencer 14 to the outside air, and the like. ing. The exhaust gas flowing from the diluter 94 through the front pipe 12 into the silencer 14 is absorbed here. The exhaust gas that has passed through the silencer 14 passes through the tail pipe 16 and is discharged from the rear end 16f (see FIG. 2) to the outside air.

  As shown in FIG. 2, the exhaust device 10 extends in the vehicle front-rear direction (indicated by an arrow Y) along the underbody lower surface 100 of the fuel cell vehicle. It is installed by suspending by etc. Exhaust pipes such as the front pipe 12 and the tail pipe 16 of the exhaust device 10 are vertically arranged to avoid vehicle components such as suspensions, fuel tanks or auxiliary tires, or to satisfy layout requirements required from a departure angle or the like. It has a portion (hereinafter referred to as a bent portion) bent in a direction (indicated by an arrow Z in the vertical upper direction).

  As shown in FIG. 2, the tail pipe 16 has two bent portions 16b and 16d. Between these bent portions, there is a portion 17 (hereinafter referred to as an inclined portion) extending obliquely upward in the vertical direction toward the flow direction of exhaust gas, that is, downstream (indicated by arrow A). On the upstream side of 17, there are a bent portion 16 b and a substantially horizontal portion 16 a (hereinafter referred to as a horizontal portion) continuous therewith.

  On the upstream side of the inclined portion 17, water condensed from exhaust gas from the fuel cell may flow and accumulate. Water that has flowed from the fuel cell through the exhaust system into the exhaust system and water formed by condensation of the moisture in the exhaust gas flowing through the exhaust system is moved downstream (indicated by arrow A) by the pressure of the exhaust flow. And flows into the horizontal portion 16 a in the tail pipe 16. However, if the flow rate of the exhaust gas discharged from the fuel cell and flowing in the exhaust system (hereinafter referred to as the exhaust gas flow rate) is small, naturally the pressure of the exhaust gas is also small, so that the water in the horizontal portion 16a is further downstream. It is impossible to climb up the inclined portion 17 and it is not discharged downstream from the inclined portion 17. As a result, water accumulates in the bent portion 16b and the horizontal portion 16a that are upstream of the inclined portion 17.

  In this way, when the exhaust flow rate is suddenly increased from the state where water is accumulated upstream from the inclined portion 17, the water flows up the inclined portion due to the pressure of the exhaust flow, and the vertical maximum position (top) of the inclined portion. Exceeding the bent portion 16d is discharged further downstream. However, when the exhaust gas flow rate is moderated from the state where water is accumulated, the slope 17 rises partway, but it cannot pass over the bent portion 16d that is the top of the slope 17 and is in the slope 17. The water may swell due to the pressure of the exhaust flow and generate noise.

  The exhaust device of the present embodiment prevents water in the inclined portion 17 from undulating when the exhaust flow rate is medium. Therefore, when the exhaust flow rate is small to medium, the water in the exhaust device is specified. When the exhaust flow rate is large and stored in a part, the stored water is discharged downstream from the inclined portion. Details will be described below with reference to FIG. FIG. 3 is a longitudinal sectional view of a portion of the exhaust device 10 surrounded by a two-dot chain line B in FIG.

  As shown in FIG. 3, the tail pipe 16 of the exhaust device 10 is formed as an exhaust passage through which exhaust from the fuel cell flows, and is formed vertically below the main passage 20. A bypass passage 30 is formed to bypass the. In addition, the cross-sectional shape of the main channel | path 20 and the bypass channel | path 30 can be made into arbitrary shapes regardless of circular and a rectangle.

  The main passage 20 is an exhaust passage through which exhaust mainly flows, and has the horizontal portion 16a, the bent portion 16b, the inclined portion 17, the bent portion 16d, and a portion 16e inclined downward toward the downstream side. . Exhaust gas containing moisture flowing into the tail pipe 16 mainly flows through the main passage 20 as indicated by an arrow A, and is discharged from the tail pipe rear end 16f.

  At this time, a part of the moisture in the exhaust gas condenses in the main passage 20 to become water, and this condensed water flows vertically downward by its own weight. The water condensed in the portion 16e of the main passage 20 flows to the tail pipe rear end 16f that is further vertically downward, and is discharged out of the exhaust device. On the other hand, the water condensed on the upstream side of the top 18 of the inclined portion 17 in the main passage 20 flows toward the horizontal portion 16a that is further vertically downward. Further, water that has flowed from the upstream side of the tail pipe 16 through the bottom 22 of the main passage 20 also flows to the horizontal portion 16a.

  The bypass passage 30 is formed vertically below the horizontal portion 16 a so as to receive water flowing from the horizontal portion 16 a of the main passage 20. The bypass passage 30 and the main passage 20 are provided on the upstream side of the inclined portion 17, on the downstream side of the inlet 32, and on the upstream side of the top 18 (corresponding to the bent portion 16 d) of the inclined portion 17. Communicating via the outlet 34. Water that has flowed from the upstream side through the bottom 22 of the main passage 20 flows into the bypass passage 30 from the inlet 32. On the other hand, the water condensed at the inclined portion 17 and flowing toward the horizontal portion 16 a flows into the bypass passage 30 from the outlet 34 and accumulates at the bottom 36 thereof. The bottom 36 of the bypass passage 30 is set lower in the vertical direction than the bottom 22 of the horizontal portion 16a of the main passage 20, and receives water flowing from the main passage 20 and temporarily stores it. Can do.

  The bypass passage 30 divides a part of the exhaust flow flowing through the main passage 20 from the inlet 32 and the exhaust flow flowing through the bypass passage 30 (hereinafter referred to as bypass flow) at the outlet 34 at the main passage 20. To the exhaust stream flowing through. When the flow rate of the bypass flow is small, the water accumulated in the bottom 36 of the bypass passage 30 is held in the bypass passage 30 and does not flow out from the outlet 34 to the main passage 20.

  On the other hand, when the flow rate of the bypass flow is large, the water stored in the bottom 36 of the bypass passage 30 is pushed out from the outlet 34 to the main passage 20 by the bypass flow. The water pushed out to the main passage 20 is carried further down the inclined portion 17 of the main passage by the bypass flow discharged from the outlet 34 to the main passage.

  In order to actively create such a state in which the flow rate of the bypass flow is large, the main passage 20 is bypassed by being located between the inlet 32 and the outlet 34 of the main passage 20, that is, the portion 20 c parallel to the bypass passage 30. The portion 20c is provided with a valve 40 for adjusting the flow rate of the exhaust flow flowing through the portion 20c.

  The valve 40 is a butterfly type, and includes a valve body 43 that restricts the exhaust flow flowing through the main passage portion 20c, a valve shaft 44 that supports the valve body 43, and a motor 46 that rotationally drives the valve shaft 44. ing. The motor 46 is drive-controlled by an electronic control unit 50 (hereinafter referred to as ECU).

  As shown in FIG. 1, the ECU 50 detects the rotational speed of the blower 86 that supplies the oxidizing gas to the fuel cell 82, and calculates the exhaust flow rate that flows through the exhaust device 10 based on this rotational speed. The ECU 50 can determine whether or not the calculated exhaust flow rate has reached a predetermined threshold value. Further, the ECU 50 can adjust the flow rate of the exhaust flow flowing through the portion 20c by controlling the motor 46 based on the determination result.

  In the above, the exhaust apparatus 10 of this embodiment and the structure of the fuel cell system 80 provided with this were demonstrated. Below, control of the exhaust apparatus 10 of this embodiment and the flow of the water in the exhaust apparatus 10 are demonstrated using FIG.

  When the fuel cell system 80 is operated, exhaust gas containing moisture flows into the exhaust device 10 from the exhaust system 88 from the fuel cell 82. Water that has condensed in the exhaust device 10 or water that has condensed on the upstream side of the exhaust device 10 and has flowed through the bottom 22 of the main passage 20 flows into the bypass passage 30 and is stored therein.

  When the exhaust gas flow rate is small to medium, that is, when the ECU 50 determines that the exhaust gas flow rate has not reached the predetermined threshold value, the valve body 43 of the valve 40 is controlled to be in the open position (shown by a solid line). . The exhaust flow that has flowed into the main passage 20 mainly flows through the portion 20c, and the flow rate of the bypass flow is small. For this reason, the water stored in the bypass passage 30 is held in the bypass passage 30 without being pushed out from the outlet 34 to the main passage 20. In this way, when the exhaust gas flow rate is small to medium, water in the bypass passage 30 is prevented from flowing out from the outlet 34 to the inclined portion 17.

  When the exhaust flow rate is large, that is, when the ECU 50 determines that the exhaust flow rate has reached a predetermined threshold value, the valve body 43 of the valve 40 is controlled to be in the closed position (indicated by a two-dot chain line), and the main passage The exhaust flow flowing through the 20 portion 20c is throttled. Thereby, most of the exhaust flow flowing into the main passage 20 flows into the bypass passage 30 from the inlet 32, and the bypass flow increases. The pressure of the bypass flow flowing in from the inlet 32 is large, and the water stored in the bypass passage 30 is pushed out from the outlet 34 to the main passage 20. As indicated by a two-dot chain line arrow C, this water is carried by the bypass flow discharged from the outlet 34 toward the inclined portion 17, rises up the inclined portion 17, passes the top 18, and further downstream. Discharged. In this way, when the exhaust gas flow rate is large, the water stored in the bypass passage 30 is blown away from the inclined portion 17 by the bypass flow.

  In the present embodiment described above, when the exhaust flow rate is small to medium, water in the exhaust device is stored in the bypass passage. When the exhaust gas flow rate is medium, the bypass passage holds water, so that it is possible to prevent the water from making waves and generating abnormal noise on the inclined portion. And the water stored by the bypass passage can be discharged | emitted downstream from the top of an inclination part by increasing the bypass flow which flows through a bypass passage, when exhaust flow volume is large.

  In this embodiment, a valve is provided in a portion of the main passage that is parallel to the bypass passage. When the exhaust flow rate is large, the valve restricts the exhaust flow flowing through the main passage, thereby increasing the bypass flow. Yes. By restricting the exhaust flow flowing through the main passage by the valve, the bypass flow can be rapidly increased, and the water stored in the bypass passage can be discharged instantaneously.

[Second Embodiment]
The configuration of the exhaust device 10B of the second embodiment will be described with reference to FIG. 4 is a vertical cross-sectional view of a portion of the exhaust device 10B surrounded by a two-dot chain line B in FIG. The exhaust device 10B of the present embodiment differs from the first embodiment in that a guide member that guides the exhaust flow of the main passage to the bypass passage is provided as means for increasing the bypass flow, and will be described in detail below. To do. In addition, about the structure substantially common with the exhaust apparatus 10 of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 3, the exhaust pipe 10 </ b> B of the exhaust device 10 </ b> B is formed as an exhaust passage through which exhaust from the fuel cell 82 flows, and is formed vertically below the main passage 60. A bypass passage 70 for bypassing the flow is formed.

  The bypass passage 70 is formed vertically downward from the horizontal portion 16 a of the main passage 60 to the downstream portion 16 c of the inclined portion 17. The bypass passage 70 and the main passage 60 communicate with each other via an inlet 72 provided on the upstream side of the inclined portion 17 and an outlet 74 provided on the approximate center of the inclined portion 17 on the upstream side of the top 18 of the inclined portion 17. is doing. A part of the exhaust flow flowing through the main passage 60 is diverted from the inlet 72, and the exhaust flow flowing through the bypass passage 70 (hereinafter referred to as bypass flow) is merged with the exhaust flow flowing through the main passage 60 at the outlet 74.

  The bypass passage 70 can store water from the main passage 60. Water flowing from the upstream side through the bottom 22 of the main passage 60 flows into the bypass passage 70 from the inlet 72, and water condensed in the downstream portion 17b of the inclined portion 17 flows into the bypass passage 70 from the outlet 74. can do. The water flowing in from the inlet 72 and the outlet 74 accumulates in the bottom 76 and can be temporarily stored therein. In addition, the water condensed by the horizontal part 16a, the bending part 16b, and the upstream part 17a of the inclination part 17 accumulates in the bottom 64 of the main channel | path 60 between the inlet 72 and the outlet 74 slightly. Become.

  A guide member 78 that guides the exhaust flow of the main passage 60 to the bypass passage 70 is provided in the vicinity of the inlet 72 of the bypass passage 70. The guide member 78 protrudes from the upstream end 64a of the bottom 64 of the main passage, and is provided to incline upward toward the upstream. Of the exhaust flow flowing through the main passage 60, the exhaust flow flowing near the bottom 64 is deflected downward by the guide member 78 and guided into the bypass passage 70 as indicated by an arrow D. Thereby, when the flow rate of the exhaust flow flowing through the main passage 60 is large, the bypass flow flowing into the bypass passage 70 from the inlet 72 can be increased.

  The configuration of the exhaust device 10B of the present embodiment has been described above. Below, the flow of the water in the exhaust apparatus 10B of this embodiment is demonstrated in detail using FIG. When the fuel cell system 80 is operated, exhaust gas containing moisture flows into the exhaust device 10 from the exhaust system 88 from the fuel cell 82.

  If the exhaust flow rate is kept low, the water flowing from the upstream side through the bottom 22 of the main passage 60 and the water condensed in the downstream portion 17b of the inclined portion 17 flow into the bypass passage 70, It is stored in. On the other hand, on the bottom 64 of the main passage 60, water condensed at the horizontal portion 16a and water condensed at the upstream portion 17a of the inclined portion 17 are slightly accumulated.

  When the exhaust flow rate is set to a medium level, the water stored in the bypass passage 70 is biased toward the outlet 74 due to the pressure of the bypass flow flowing from the inlet 72. However, since the outlet 74 is set in the middle of the inclined portion 17 and the pressure of the bypass flow is not so large, the water stored in the bypass passage 70 “extrudes” from the outlet 74 to the main passage 60. Absent. At this time, the water accumulated in the bottom 64 of the main passage 60 is carried to the exhaust flow flowing through the main passage 60, and as shown by the arrow E, rises on the downstream portion 16 c of the inclined portion 17 and from the outlet 74. It flows into the bypass passage 70 and is stored. In this way, when the exhaust gas flow rate is small to medium, the condensed water is prevented from hitting the wave at the downstream portion 16c of the inclined portion.

  When the exhaust flow rate becomes large, more exhaust flow is guided to the bypass passage 70 by the guide member 78, and the bypass flow increases. At this time, the water stored in the bypass passage 70 is pushed out from the outlet 74 to the inclined portion 17 of the main passage 60 as indicated by a two-dot chain line arrow F. This water is carried by the bypass flow discharged from the outlet 74 toward the inclined portion 17 and the exhaust flow flowing through the main passage 60 without passing through the bypass passage 70, and is applied to the downstream portion 17 b of the inclined portion 17. It goes up, passes over the top 18 and is discharged further downstream.

  In the present embodiment described above, when the exhaust flow rate is small, the water in the exhaust device is stored in the bypass passage, and when the exhaust flow rate is medium, the water flowing up the inclined portion by the exhaust flow of the main passage is It flows into the bypass passage from the middle of the inclined portion and stores it. When the exhaust flow rate is large, the bypass flow is increased by the guide member, so the water stored in the bypass passage is pushed out of the bypass passage and discharged downstream from the top of the inclined portion. As a result, when the exhaust gas flow rate is medium, the water that rises up the inclined portion flows into the bypass passage and is held, so that it is possible to prevent the water from making waves and generating noise in the inclined portion. The water stored in the bypass passage can be discharged downstream from the top of the inclined portion when the exhaust flow rate is large.

  In the first and second embodiments, the bypass pipe and the means for increasing the bypass flow are provided in the tail pipe, but the present invention is not limited to this. As long as the exhaust passage has an inclined portion that is inclined upward toward the downstream, the bypass passage and the bypass flow increasing means of the present invention can be applied, and for example, can be provided in the front pipe.

It is a figure which shows the system configuration | structure of a fuel cell system. It is a side view of an exhaust apparatus. It is a longitudinal cross-sectional view of the exhaust apparatus which concerns on 1st Embodiment, and is sectional drawing of the site | part enclosed with the dashed-two dotted line B in FIG. It is a longitudinal cross-sectional view of the exhaust apparatus which concerns on 2nd Embodiment, and is sectional drawing of the site | part enclosed with the dashed-two dotted line B in FIG.

Explanation of symbols

  10, 10B Exhaust device, 16, 16B Tail pipe, 17 Inclined portion, 18 Top, 20 Main passage, 30 Bypass passage, 40 Valve, 50 Electronic control unit (ECU), 60 Main passage, 70 Bypass passage, 78 Guide member, 80 Fuel cell system, 88 Exhaust system, 100 Underside of vehicle underbody.

Claims (5)

An exhaust system that is mounted on a fuel cell vehicle and includes an exhaust passage through which exhaust from the fuel cell flows,
The exhaust passage is
A main passage including an inclined portion that is inclined vertically upward toward the downstream;
An inclined portion that is provided vertically below the main passage, can store water from the main passage, and diverts the exhaust flow flowing through the main passage from the upstream side of the inclined portion, and extends obliquely upward with respect to the vertical direction. A bypass passage that joins upstream from the highest position in the vertical direction;
Have
A bypass flow increasing means for increasing a bypass flow that is an exhaust flow flowing through the bypass passage when the exhaust flow rate is large,
Exhaust device for fuel cell vehicles. The exhaust device for a fuel cell vehicle according to claim 1,
Bypass flow increasing means
Provided in a portion of the main passage parallel to the bypass passage, and provided with a valve that is controlled to restrict the exhaust flow flowing through the main passage when the exhaust flow rate reaches a predetermined threshold value.
Exhaust device for fuel cell vehicles. An exhaust device for a fuel cell vehicle according to claim 2,
The valve is an exhaust device for a fuel cell vehicle, in which it is determined whether or not the exhaust flow rate has reached a predetermined threshold based on a parameter relating to a gas discharge amount from a blower that supplies oxidizing gas to the fuel cell. The exhaust device for a fuel cell vehicle according to claim 1,
Bypass flow increasing means
A guide member provided near the inlet of the bypass passage and guiding the exhaust flow of the main passage to the bypass passage.
Exhaust device for fuel cell vehicles. The exhaust device for a fuel cell vehicle according to any one of claims 1 to 4,
The part where the bypass passage merges with the main passage is set in the middle of the inclined portion,
Exhaust device for fuel cell vehicles.

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