An exhaust gas treatment device for a hydrogen fuel cell

Abstract

The application relates to the field of hydrogen fuel cells, in particular to a tail gas treatment device for a hydrogen fuel cell. The device comprises a tail gas discharge pipeline, a self-starting air supplementing mechanism, a plurality of groups of one-way valves which are uniformly distributed along the tail gas discharge pipeline in the axial direction, wherein the one-way valves are composed of elastic valve sheets, the tail gas discharge pipeline is provided with air holes corresponding to the positions of the elastic valve sheets, the exhaust end of the tail gas discharge pipeline is provided with a flame arrester, and the connection part of the flame arrester and the tail gas discharge pipeline is provided with a honeycomb-shaped catalytic structure. The self-starting air supplementing mechanism automatically introduces air under the effect of high-speed airflow entrainment, and the spiral flow guide ribs of the inner tube form strong spiral flow, so that the air inhaled through the air holes and the hydrogen-containing tail gas generate strong turbulent spiral flow in the mixing cavity, and the hydrogen is efficiently and uniformly diluted.

Description

Technical Field

[0001] This invention relates to the field of hydrogen fuel cells, and more specifically to an exhaust gas treatment device for hydrogen fuel cells. Background Technology

[0002] In hydrogen fuel cell applications, unreacted hydrogen at the anode is discharged with the exhaust gas. If directly discharged into a closed or semi-closed space, it can easily accumulate locally, forming an explosive gas mixture, posing a serious safety hazard. In existing technologies, some systems use simple direct discharge or passive ventilation to treat the exhaust gas, lacking effective control over hydrogen concentration and making it difficult to guarantee dilution effects.

[0003] A hydrogen fuel cell exhaust gas mixing and dilution device and a hydrogen fuel cell, currently disclosed in Chinese Patent Publication No. CN118431524B, include an integrally structured exhaust gas main pipe and exhaust gas inlet pipe. The exhaust gas main pipe has a mounting groove at its bottom. An air supply shell covers the outer side of the exhaust gas inlet pipe, and a mounting bracket is installed on the top of the air supply shell. An air supply fan is installed on one side of the air supply shell, and a heat dissipation shell is installed on the other side of the air supply shell. A silencer is installed on one side of the heat dissipation shell. The silencer is fitted onto the outer side of the exhaust gas main pipe, and a connection is installed on the outer side of the silencer to the exhaust gas... The main pipe has a protective sleeve for connection. One end of the mounting slot is equipped with an air replenishment and dilution mechanism, and a transition square tube is installed between the air replenishment and dilution mechanism and the air replenishment housing. The top of the air replenishment and dilution mechanism has multiple rows of obliquely distributed conical hoses, and the top inner wall of the tail exhaust main pipe has multiple oblique turbulence plates that are staggered with each row of conical hoses. The top of the transition square tube is equipped with an exhaust mixing mechanism, which is located in the transition area between the tail exhaust main pipe and the tail exhaust inlet pipe. The bottom of the air replenishment housing is provided with a plug-in slot, and an air filter mechanism is installed inside the plug-in slot. The air filter mechanism is located at the air outlet of the air replenishment fan.

[0004] According to the aforementioned patent, by setting up an air intake fan, a transition square tube, and an air intake dilution mechanism around the exhaust pipe, the patent utilizes the oncoming airflow for natural air intake when the vehicle is at high speed, and actively blows in air when idling or at low speed, so that the air is obliquely injected into the exhaust flow through a conical hose, thereby achieving rapid dilution and cooling of hydrogen-containing exhaust gas.

[0005] However, the aforementioned patents suffer from drawbacks such as reliance on active air replenishment by a fan, complex structure, and lack of concentration feedback. Therefore, there is a current need for an exhaust gas treatment device for hydrogen fuel cells that can automatically introduce air by utilizing the pressure difference generated when the exhaust gas is discharged, without the need for a fan or electronic control system. It can introduce ambient air through a self-priming ejector principle to form convective mixing and achieve efficient dilution of hydrogen. Summary of the Invention

[0006] To address the problems existing in the prior art, a tail gas treatment device for hydrogen fuel cells is provided. The device automatically introduces air through a self-starting air supply mechanism under the ejection effect of high-speed airflow, and uses the spiral guide ribs of the inner tube to form a strong swirling flow. This causes the air drawn in through the air hole to generate a strong turbulent swirling flow with the hydrogen-containing tail gas in the mixing chamber, thereby efficiently and uniformly diluting the hydrogen gas.

[0007] To address the problems of existing technologies, this invention provides a tail gas treatment device for hydrogen fuel cells, used for generating electrical energy through electrochemical reactions and discharging anode tail gas containing unreacted hydrogen. The device includes a tail gas discharge pipeline for discharging tail gas, a self-opening gas replenishment mechanism disposed around the tail gas discharge pipeline, and multiple sets of one-way valves evenly distributed along the axial direction of the tail gas discharge pipeline. Each one-way valve is composed of an elastic valve plate, one end of which is fixed to the inside of the tail gas discharge pipeline and faces the tail gas discharge direction, while the other end is a free-moving end. The tail gas discharge pipeline has vent holes corresponding to the positions of each elastic valve plate. In the absence of tail gas flow, the elastic valve plate covers the vent holes due to its own elastic force and is in a closed state. In the case of high-speed tail gas ejection, the elastic valve plate detaches from the vent holes due to gas pressure and is in an open state. A flame arrester is provided at the exhaust end of the tail gas discharge pipeline to prevent external flames from escaping back into the interior of the tail gas discharge pipeline. A honeycomb catalytic structure is provided at the connection between the flame arrester and the tail gas discharge pipeline for catalytic oxidation of hydrogen in the tail gas.

[0008] Preferably, the exhaust gas emission pipe is coaxially provided with an inner pipe, and an inner annular air cavity is formed between the inner pipe and the exhaust gas emission pipe. The interior of the inner pipe forms a mixing cavity, and several through grooves are opened on the periphery of the inner pipe. The inner wall of the inner pipe is provided with spiral guide ribs along its axial direction.

[0009] Preferably, an outer pipe is coaxially provided outside the exhaust gas emission pipe, and an outer annular air cavity is formed between the outer pipe and the exhaust gas emission pipe. Several through holes are opened on the periphery of the outer pipe to form an outer protective layer for air circulation.

[0010] Preferably, the inner side of the outer tube is provided with a hydrophobic and breathable membrane, which covers the inner side of the through hole to allow gas to pass through and prevent liquid water and particulate foreign matter from entering the exhaust gas pipeline.

[0011] Preferably, a ring is fitted on the inner tube for each group of elastic valve pieces, and the ring forms an outer limiting part on the outer side of the elastic valve piece to limit the maximum deformation displacement of the elastic valve piece in the open state.

[0012] Preferably, the elastic valve plate has a sealing gasket on the side facing the air hole, and the inner edge of the air hole has a step that cooperates with the sealing gasket.

[0013] Preferably, a guide bucket is provided on the outside of the exhaust pipe for each air hole. The opening of the guide bucket faces outward and is flared. Its inner end is connected to the air hole to guide ambient air in.

[0014] Preferably, the drainage hopper is provided with a support member, and a tension spring is fixedly connected between the support member and the elastic valve plate. When the elastic valve plate is opened, the tension spring is in a stretched state.

[0015] Preferably, the support member is a spherical structure with a smooth curved surface, used to reduce the flow resistance when airflow passes through the guide bucket.

[0016] Preferably, the flame arrester has a metal mesh coaxial with the exhaust pipe along the exhaust gas discharge direction on its inner side.

[0017] The advantages of this application compared to the prior art are:

[0018] 1. This invention utilizes a self-opening air supply mechanism consisting of an elastic valve plate and vents installed around the exhaust pipe. When there is no exhaust gas, the vents automatically seal to prevent dust and water ingress due to elastic force. During high-speed exhaust gas ejection, the exhaust gas flows along the exhaust pipe and forms a high-speed jet near the vents. According to Bernoulli's principle, the increased flow velocity leads to a decrease in local static pressure in this area, causing the pressure inside the pipe at the vents to be lower than the external atmospheric pressure. This creates a pressure difference from the outside to the inside on both sides of the elastic valve plate. This pressure difference overcomes the elasticity of the valve plate, causing it to open inwards, allowing ambient air to be drawn into the pipe through the vents and mixed and diluted with the hydrogen exhaust gas. Furthermore, a flame arrester is installed at the exhaust end, utilizing its metal mesh structure to extinguish any backdraft flames.

[0019] Meanwhile, a honeycomb catalytic structure is integrated at the connection between the flame arrester and the pipeline, which causes residual hydrogen to generate water vapor. Thus, through the triple mechanism of passive gas replenishment dilution, chemical catalysis, and physical flame arrest, efficient and safe exhaust treatment without external energy is achieved.

[0020] 2. This invention forms an inner annular air chamber and a mixing chamber by setting a coaxial inner tube in the exhaust gas pipeline, combined with circumferential through grooves and axial spiral guide ribs, so that the air drawn in through the air hole and the hydrogen-containing exhaust gas generate strong turbulent swirling flow in the mixing chamber, which efficiently and uniformly dilutes the hydrogen gas.

[0021] The resilient valve plate automatically opens to introduce air under pressure difference. An outer ring prevents excessive deformation of the valve plate, and a sealing gasket and vent step ensure airtight and liquid-tight sealing when the machine stops. The entire structure requires no external power source to achieve reliable air supply, efficient mixing, and prevention of foreign object intrusion.

[0022] 3. The present invention forms an outer annular air cavity between the outer pipe and the exhaust gas emission pipe, and opens through holes on the periphery of the outer pipe and sets a hydrophobic and breathable membrane on the inner side, so that external air continuously flows in when the vehicle is running or the exhaust gas is being ejected at high speed, forming a dynamic outer protective layer around the pipe.

[0023] With the protection of the outer protective layer, it not only provides heat insulation and cooling for the high-temperature exhaust gas pipeline, but also allows gas to flow freely while effectively blocking the intrusion of liquid and solid foreign objects such as rainwater and dust through the selective permeability of the through holes and hydrophobic and breathable membrane, thus achieving multiple protective effects of aerodynamic cooling, physical shielding and hydrophobic antifouling. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural schematic diagram of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0025] Figure 2 This is a three-dimensional structural cross-sectional view of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0026] Figure 3 This is a planar sectional view of an exhaust gas treatment device for a hydrogen fuel cell according to the present invention.

[0027] Figure 4 This is a partial three-dimensional structural cross-sectional view of the exhaust gas emission pipeline of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0028] Figure 5 This is a partial axial planar cross-sectional view of the exhaust gas emission pipeline of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0029] Figure 6 This is a radial partial three-dimensional structural cross-sectional view of the exhaust gas emission pipeline of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0030] Figure 7 This is the invention Figure 6 Enlarged diagram of point A.

[0031] Figure 8 This is a three-dimensional exploded view of the exhaust gas emission pipeline and outer pipe of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0032] Figure 9 This is an exploded three-dimensional structural diagram of the inner and outer interlayers of the exhaust gas emission pipeline of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0033] Figure 10 This is a three-dimensional exploded view of the exhaust gas emission pipeline and inner pipe of an exhaust gas treatment device for hydrogen fuel cells according to the present invention.

[0034] The following are the labels in the diagram: 1. Exhaust gas emission pipe; 11. Vent; 111. Step; 12. Drainage hopper; 13. Support component; 131. Tension spring; 14. Inner jacket; 15. Outer jacket; 2. Elastic valve plate; 21. Sealing gasket; 3. Flame arrester; 31. Metal mesh; 4. Honeycomb catalytic structure; 5. Inner pipe; 51. Inner annular gas chamber; 52. Mixing chamber; 521. Through groove; 522. Spiral guide rib; 53. Ring sleeve; 6. Outer pipe; 61. Outer annular gas chamber; 611. Through hole; 62. Hydrophobic and breathable membrane. Detailed Implementation

[0035] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0036] See Figures 1 to 5 As shown, a tail gas treatment device for a hydrogen fuel cell is used to generate electricity through an electrochemical reaction and to discharge anode tail gas containing unreacted hydrogen. It includes a tail gas discharge pipe 1 for discharging tail gas. A self-opening gas replenishment mechanism is disposed around the tail gas discharge pipe 1 and includes multiple sets of one-way valves evenly distributed along the axial direction of the tail gas discharge pipe 1. Each one-way valve is composed of an elastic valve plate 2, one end of which is fixed to the inside of the tail gas discharge pipe 1 and faces the tail gas discharge direction, while the other end is a free-moving end. Each elastic valve plate 2 in the tail gas discharge pipe 1 has a vent 11 corresponding to its position. In the absence of tail gas flow, the elastic valve plate 2 covers the vent 11 due to its own elastic force and is in a closed state. In the case of high-speed tail gas discharge, the elastic valve plate 2 disengages from the vent 11 due to air pressure and is in an open state. A flame arrester 3 is provided at the exhaust end of the tail gas discharge pipe 1 to prevent external flames from escaping back into the tail gas discharge pipe 1. The connection between the flame arrester 3 and the exhaust gas pipeline 1 is provided with a honeycomb catalytic structure 4, which is used to catalytically oxidize the hydrogen in the exhaust gas.

[0037] The exhaust gas treatment device is mainly designed to meet the safety emission requirements of anode exhaust gas in hydrogen fuel cell systems in new energy vehicles. However, based on its core functions of diluting, catalytically oxidizing, and preventing backfire of hydrogen-containing exhaust gas, it is also applicable to stationary power plants, backup power supplies for communication base stations, rail transit, ships, drones, and other distributed or mobile energy systems that use hydrogen fuel cells. It can be applied to any scenario involving the safe disposal of low-concentration hydrogen exhaust gas.

[0038] In a hydrogen fuel cell, hydrogen undergoes an oxidation reaction at the anode, producing electrical energy, protons, and electrons. Unreacted hydrogen is discharged from the anode outlet along with the anode exhaust gas and enters the exhaust pipe 1, which is connected to it. The exhaust pipe 1 serves as the main channel, directing the hydrogen-containing exhaust gas to the exhaust end at the rear or bottom of the vehicle.

[0039] When the system is shut down or there is no exhaust gas flow, the elastic valve plate 2 naturally rebounds due to the elastic force of its own material, so that its free end is tightly attached to and completely covers the corresponding air hole 11, thereby keeping it closed and effectively preventing external dust, rainwater or foreign objects from entering the pipeline through the air hole 11.

[0040] When the exhaust gas is ejected at high speed, it flows along the exhaust pipe 1 and forms a high-speed jet near the vent 11. According to Bernoulli's principle, the increased flow velocity leads to a decrease in local static pressure in this area, making the pressure inside the pipe at the vent 11 lower than the external atmospheric pressure. This creates a pressure difference from the outside to the inside on both sides of the elastic valve plate 2. This pressure difference overcomes the elasticity of the valve plate 2, causing it to open inward, allowing ambient air to be drawn into the pipe through the vent and mixed with the hydrogen exhaust gas for dilution. This achieves initial dilution of the hydrogen, reducing its local concentration and preventing its accumulation under the vehicle or in confined spaces, thus preventing the formation of explosive gases.

[0041] Subsequently, the diluted exhaust gas continues to flow to the exhaust end of exhaust gas discharge pipe 1, where a flame arrester 3 is installed. As a critical safety barrier, the flame arrester 3 is designed to allow the gas to be discharged normally, but if an open flame or spark attempts to enter the pipe through the exhaust port, the flame arrester 3 will quickly absorb the heat of the flame, causing the temperature of the hydrogen flame to drop below its ignition point and extinguish it, thereby effectively preventing the flame from spreading into the pipe.

[0042] Furthermore, a honeycomb catalytic structure 4 is integrated at the connection interface between the flame arrester 3 and the exhaust pipe 1. The honeycomb catalytic structure 4 includes a porous ceramic support and a platinum-based catalyst supported on its surface.

[0043] When exhaust gas containing trace amounts of hydrogen flows through the honeycomb catalytic structure 4, under normal or low temperature conditions, the hydrogen reacts with oxygen in the air on the catalyst surface in a flameless catalytic oxidation reaction, generating water vapor. This further reduces the content of combustible hydrogen in the exhaust gas, achieving dual safety assurance. The entire process requires no external energy, sensors, or active control; it relies entirely on the exhaust gas flow state to automatically trigger gas replenishment, mixing, catalysis, and flame arrestor, forming a highly efficient, reliable, and inherently safe exhaust treatment mechanism.

[0044] Considering that the exhaust gas from the anode of a hydrogen fuel cell is usually in a high-humidity state, the honeycomb catalytic structure 4 uses a hydrophobically modified porous ceramic support and is loaded with a platinum-based catalyst to prevent liquid water from covering the active sites and reducing the catalytic oxidation efficiency.

[0045] The elastic valve plate 2 is made of moisture-resistant and hydrogen-resistant fluororubber or silicone-fluorocomposite material to avoid reset failure or adhesion due to water film adsorption.

[0046] See Figures 2 to 7 and Figure 10As shown, an inner tube 5 is coaxially arranged inside the exhaust gas emission pipe 1. An inner annular air cavity 51 is formed between the inner tube 5 and the exhaust gas emission pipe 1. A mixing cavity 52 is formed inside the inner tube 5. Several through grooves 521 are opened on the periphery of the inner tube 5. A spiral guide rib 522 is provided on the inner wall of the inner tube 5 along its axial direction.

[0047] To mitigate the risks posed by the 4%–75% explosion limit of hydrogen in air, the exhaust gas treatment device employs multiple safety designs:

[0048] First, air is introduced only as needed during exhaust gas flow via a self-starting air supply mechanism, and the air supply volume is controlled by the adaptive limit of the elastic valve plate 2 to ensure that hydrogen is rapidly diluted to below a safe concentration.

[0049] Subsequently, the spiral guide ribs 522 of the inner tube 5 promote efficient and uniform mixing of hydrogen and air, avoiding local enrichment.

[0050] Next, the honeycomb catalytic structure 4, located adjacent to the exhaust end, catalytically oxidizes the hydrogen into water at a low temperature before it reaches a dangerous concentration. Simultaneously, the flame arrester 3 prevents external flame backflow. This achieves inherently safe operation through controlled dilution, thorough mixing, active elimination, and physical flame arrest.

[0051] When the exhaust gas is discharged at high speed, ambient air is drawn in through the vents 11 on the pipe wall by the self-opening air replenishment mechanism and enters the inner annular air chamber 51 formed between the exhaust gas discharge pipe 1 and the coaxially arranged inner pipe 5. Subsequently, driven by the pressure difference, this replenished air flows from the inner annular air chamber 51 into the mixing chamber 52 inside the inner pipe 5 through several through slots 521 opened on the periphery of the inner pipe 5. At this time, the high-speed discharged hydrogen-containing exhaust gas also enters the mixing chamber 52 simultaneously and merges with the air radially injected from the through slots 521.

[0052] Because the inner wall of the inner tube 5 is provided with spiral guide ribs 522 along the axial direction, the mixture of exhaust gas and air is forced to rotate along the spiral path during its forward flow, forming strong turbulence and vortex effects. This process enhances the mixing efficiency between hydrogen and air, allowing the hydrogen to be rapidly and uniformly diluted to below a safe concentration. At the same time, the spiral guide ribs 522 prolong the residence time of the gas in the mixing chamber 52, providing more sufficient contact conditions for the subsequent oxidation reaction when flowing through the catalytic structure.

[0053] See Figures 2 to 7 and Figure 9 As shown, an outer pipe 6 is coaxially provided outside the exhaust gas emission pipe 1, and an outer annular air cavity 61 is formed between the outer pipe 6 and the exhaust gas emission pipe 1. Several through holes 611 are opened on the periphery of the outer pipe 6 to form an outer protective layer for air circulation.

[0054] When the vehicle is in operation, ambient air flows naturally into the outer annular air chamber 61 through several through holes 611 on the circumference of the outer pipe 6. Especially during vehicle operation, the oncoming airflow will accelerate the air to enter through the through holes 611.

[0055] The air entering the outer annular air chamber 61 does not mix directly with the exhaust gas, but flows continuously around the exhaust gas emission pipe 1, forming a dynamic outer protective layer. This air layer serves two purposes: firstly, it insulates and cools the high-temperature exhaust gas emission pipe 1, reducing the temperature of the pipe's outer surface; secondly, because the through holes 611 are typically small in size and have a certain density, they effectively prevent foreign objects from directly contacting the exhaust gas emission pipe 1 body while allowing airflow, thus forming a dual protection system of physical and aerodynamics.

[0056] See Figures 2 to 8 As shown, the inner side of the outer tube 6 is provided with a hydrophobic and breathable membrane 62, which covers the inner side of the through hole 611 to allow gas to pass through and block liquid water and particulate foreign matter from entering the exhaust gas emission pipe 1.

[0057] When outside air attempts to enter the outer annular air cavity 61, it must first pass through the hydrophobic and breathable membrane 62. Because the hydrophobic and breathable membrane 62 has a microporous structure and its surface is hydrophobically treated, gas molecules can freely pass through the membrane into the outer annular air cavity 61, maintaining normal airflow and protective functions.

[0058] When encountering liquid water, the hydrophobic properties cause the water to form droplets on its surface and prevent it from penetrating the micropores due to surface tension, thus effectively blocking it from entering. Similarly, particulate matter such as dust and sand particles larger than the membrane pore size are also physically intercepted. While ensuring continuous airflow to form an outer protective layer, the hydrophobic and breathable membrane 62 acts as a selective barrier, allowing only gas to pass through and preventing liquid and solid contaminants from entering, thus avoiding moisture condensation that corrodes the pipes and foreign objects that clog the pipes.

[0059] See Figure 2 and Figure 3 As shown, a ring 53 is fitted on the inner tube 5 for each group of elastic valve plates 2. The ring 53 forms an outer limiting part on the outer side of the elastic valve plate 2, which is used to limit the maximum deformation displacement of the elastic valve plate 2 in the open state.

[0060] During the exhaust gas emission process, when the hydrogen-containing exhaust gas is ejected at high speed, the exhaust gas flows in the exhaust gas emission pipe 1. The pressure difference acts on the free end of the elastic valve plate 2, causing it to overcome its own elasticity and deflect outward, thereby opening the corresponding vent 11 and introducing ambient air to dilute the hydrogen.

[0061] To prevent excessive deformation, overturning, or even fatigue fracture of the elastic valve plate 2, a ring 53 is fitted on the inner tube 5 corresponding to the position of each set of elastic valve plates 2. When the elastic valve plate 2 opens and swings outward, its free end will contact and be blocked by the outer limiting part after moving to a certain angle, thereby limiting its further outward deformation. This limiting mechanism effectively controls the maximum displacement and opening degree of the elastic valve plate 2 in the open state, ensuring sufficient air intake area to meet dilution requirements, while avoiding the risk of material stress concentration and rebound failure caused by excessive opening.

[0062] After the exhaust gas stops being emitted, the elastic valve plate 2 returns to its original position smoothly by relying on its own elastic force, and covers the air hole 11 again to achieve a seal.

[0063] See Figure 2 and Figure 3 As shown, the elastic valve plate 2 is provided with a sealing gasket 21 on the side facing the air hole 11, and the inner edge of the air hole 11 is provided with a step 111 that cooperates with the sealing gasket 21.

[0064] In the absence of exhaust gas flow, the elastic valve plate 2 naturally rebounds due to the elastic restoring force of its material, causing it to tightly adhere to the side facing the vent 11 at the location of the vent 11. At this time, the sealing gasket 21 on that side of the elastic valve plate 2 is pressed against the step 111 provided on the inner edge of the vent 11. After the two are in contact, the sealing gasket 21 undergoes slight deformation under the action of pre-tightening force, filling the microscopic uneven gaps, thereby forming a reliable airtight and liquid-tight seal around the vent 11, effectively preventing external rainwater, dust, mud, or other particulate foreign matter from entering the exhaust gas emission pipe 1 through the vent 11.

[0065] See Figure 2 and Figure 3 As shown, each air hole 11 on the outside of the exhaust pipe 1 is provided with a guide bucket 12. The opening of the guide bucket 12 faces outward and is flared. Its inner end is connected to the air hole 11 to guide ambient air in.

[0066] The exhaust gas emission pipe 1 has a double-layer structure, including an inner layer 14 and an outer layer 15. The diversion hopper 12 is embedded and fixed in the cavity between the inner layer 14 and the outer layer 15.

[0067] When there is no airflow in the exhaust pipe 1, the guide bucket 12 is stationary in the cavity between the inner jacket 14 and the outer jacket 15, with its flared opening facing outwards and remaining open. Once the hydrogen-containing exhaust gas is discharged at high speed, a pressure difference is formed inside and outside the exhaust pipe 1. This pressure difference is transmitted to the inside of the guide bucket 12 through the vent 11, causing ambient air to be actively drawn into the flared guide bucket 12. Guided by the inner wall of the guide bucket 12, the air converges and flows precisely axially into the vent 11, entering the exhaust pipe 1 and rapidly mixing and diluting with the hydrogen exhaust gas.

[0068] See Figures 2 to 7 As shown, a support member 13 is provided inside the drainage bucket 12. A tension spring 131 is fixedly connected between the support member 13 and the elastic valve plate 2. When the elastic valve plate 2 is opened, the tension spring 131 is in a stretched state.

[0069] During exhaust gas emission, when hydrogen-containing exhaust gas is ejected at high speed, the high-speed airflow generated within the exhaust gas emission pipe 1 causes the free end of the elastic valve plate 2 to deflect outward against its own elasticity, thereby opening the vent 11. At this time, the tension spring 131 connecting the elastic valve plate 2 and the support member 13 inside the diversion hopper 12 is gradually stretched and enters a stretched state, which provides a buffer for the opening movement of the valve plate and prevents violent overturning.

[0070] On the other hand, after the exhaust gas stops being emitted, the tension spring 131 actively pulls back the free end of the elastic valve plate 2 by relying on its restoring force, assisting it to quickly and reliably reset to the closed position, ensuring that the sealing gasket 21 re-presses the air hole 11 step 111, and achieves effective sealing.

[0071] See Figure 7 As shown, the support member 13 is a spherical structure with a smooth curved surface, which is used to reduce the flow resistance when the airflow passes through the guide bucket 12.

[0072] When ambient air is drawn into the diversion hopper 12 and flows through its interior, the airflow encounters the spherical support 13. Due to its streamlined shape without sharp edges or abrupt changes, the airflow can smoothly flow around the smooth curved surface, effectively avoiding the generation of eddies, separation, or local pressure loss. This low-disturbance flow characteristic reduces the flow resistance of air passing through the diversion hopper 12, ensuring a smoother and more efficient air replenishment process.

[0073] See Figure 2 and Figure 3 As shown, the flame arrester 3 has a metal mesh 31 coaxial with the exhaust pipe 1 along the exhaust gas discharge direction on its inner side.

[0074] The surface of the metal mesh 31 is treated with a hydrophobic coating, and an exhaust gap is reserved between it and the upstream catalytic section to prevent condensate from accumulating and clogging, thereby ensuring flame-retardant performance and long-term operational stability.

[0075] When the hydrogen-containing exhaust gas is discharged from the exhaust gas discharge pipe 1 and enters the flame arrester 3, the airflow flows straight through the interior of the flame arrester 3 axially. Since the metal mesh 31 is coaxially arranged with the exhaust gas discharge pipe 1, the exhaust gas passes evenly through the microporous channels of the metal mesh 31, and there will be no airflow disturbance or sudden velocity change due to eccentricity or partial obstruction.

[0076] If an external ignition source causes backfire at the exhaust port, the flame front enters the flame arrester 3 during its reverse propagation and is immediately divided into multiple tiny flames by the coaxially arranged metal mesh 31. The metal mesh 31, with its high thermal conductivity and large specific surface area, rapidly absorbs and dissipates combustion heat, causing the flame temperature to drop sharply below the ignition point of hydrogen, thereby quenching the flame in a very short time and effectively preventing its continued propagation.

[0077] This invention utilizes the principle that, when exhaust gas flows at high speed, it forms a high-speed jet near the vent 11 along the exhaust pipe 1. The increased flow velocity leads to a decrease in local static pressure in this area, making the pressure inside the pipe at the vent 11 lower than the external atmospheric pressure. This creates a pressure difference from the outside to the inside on both sides of the elastic valve plate 2. This pressure difference overcomes the elasticity of the valve plate 2, causing it to open inward, allowing ambient air to be drawn into the pipe through the vent and mixed with the hydrogen exhaust gas. This air first enters the outer annular gas chamber 61, then passes through the circumferential groove 521 of the inner pipe 5 into the central mixing chamber 52, where it merges with the hydrogen-containing exhaust gas. Thanks to the axial spiral guide ribs 522 on the inner wall of the inner pipe 5, the mixed gas forms a strong swirling and turbulent flow, rapidly and uniformly diluting the hydrogen to below a safe concentration.

[0078] Meanwhile, by covering the inner side of the outer pipe 6 with a hydrophobic and breathable membrane 62, air can continuously flow in to form a dynamic outer protective layer while effectively blocking rainwater and dust intrusion, and also providing heat insulation and cooling for the exhaust pipe 1. The exhaust gas finally flows through the exhaust end, where it first passes through the honeycomb catalytic structure 4 to catalytically oxidize the residual hydrogen into water vapor at room temperature, and then passes through the metal mesh 31 and the flame arrester 3 to extinguish any possible backflash.

[0079] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A tail gas treatment device for a hydrogen fuel cell, used to generate electrical energy through an electrochemical reaction and to discharge anode tail gas containing unreacted hydrogen; Its features are, include: Exhaust gas discharge pipe, used to discharge exhaust gas; A self-starting air replenishment mechanism is provided around the exhaust gas emission pipe and includes multiple sets of one-way valves evenly distributed along the axial direction of the exhaust gas emission pipe. Each one-way valve is composed of an elastic valve plate. One end of the elastic valve plate is fixed to the inside of the exhaust gas emission pipe and faces the exhaust gas discharge direction, while the other end is a free-moving end. The exhaust pipe is provided with air holes corresponding to the position of each of the elastic valve plates; When there is no exhaust gas flow, the elastic valve plate covers the air hole due to its own elastic force and is in a closed state; When the exhaust gas is ejected at high speed, the elastic valve plate is disengaged from the air hole due to air pressure and is in the open state. The exhaust end of the exhaust pipe is equipped with a flame arrester to prevent external flames from spreading back into the exhaust pipe. The connection between the flame arrester and the exhaust gas pipeline is equipped with a honeycomb catalytic structure for catalytic oxidation of hydrogen in the exhaust gas.

2. The exhaust gas treatment device for hydrogen fuel cells according to claim 1, characterized in that, The exhaust gas emission pipe is coaxially provided with an inner pipe, and an inner annular air cavity is formed between the inner pipe and the exhaust gas emission pipe. The interior of the inner pipe forms a mixing cavity. Several through grooves are opened on the periphery of the inner pipe, and spiral guide ribs are provided on the inner wall of the inner pipe along its axial direction.

3. The exhaust gas treatment device for hydrogen fuel cells according to claim 2, characterized in that, An outer pipe is coaxially provided outside the exhaust gas emission pipe, and an outer annular air cavity is formed between the outer pipe and the exhaust gas emission pipe. Several through holes are opened on the periphery of the outer pipe to form an outer protective layer for air circulation.

4. The exhaust gas treatment device for hydrogen fuel cells according to claim 3, characterized in that, The inner side of the outer tube is provided with a hydrophobic and breathable membrane, which covers the inner side of the through hole to allow gas to pass through and prevent liquid water and particulate foreign matter from entering the exhaust gas pipeline.

5. The exhaust gas treatment device for a hydrogen fuel cell according to claim 2, characterized in that, Each set of elastic valve plates is fitted with a ring on the inner tube. The ring forms an outer limiting part on the outer side of the elastic valve plate, which is used to limit the maximum deformation displacement of the elastic valve plate in the open state.

6. The exhaust gas treatment device for a hydrogen fuel cell according to claim 5, characterized in that, The elastic valve plate has a sealing gasket on the side facing the air hole, and the inner edge of the air hole has a step that cooperates with the sealing gasket.

7. The exhaust gas treatment device for a hydrogen fuel cell according to claim 5, characterized in that, Each exhaust pipe has a diversion funnel on its outer side corresponding to each air hole. The opening of the diversion funnel faces outward and is flared. Its inner end is connected to the air hole to guide ambient air in.

8. The exhaust gas treatment device for a hydrogen fuel cell according to claim 7, characterized in that, The drainage hopper is equipped with a support member, and a tension spring is fixedly connected between the support member and the elastic valve plate. When the elastic valve plate is opened, the tension spring is in a stretched state.

9. A tail gas treatment device for a hydrogen fuel cell according to claim 8, characterized in that, The support is a spherical structure with a smooth curved surface, which is used to reduce the flow resistance when the airflow passes through the guide bucket.

10. A tail gas treatment device for a hydrogen fuel cell according to claim 1, characterized in that, The flame arrester has a metal mesh on its inner side that is coaxial with the exhaust pipe along the direction of the exhaust gas discharge.

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