Fuel cell air filter device with replaceable harmful gas filter structure

Abstract

The application discloses a fuel cell air filtering device with a harmful gas filtering structure which can be replaced individually, comprising a cylindrical shell, a maintenance end cover arranged at one axial end of the shell, an air outlet connected to the other axial end of the shell, an air inlet connected to the circumferential sidewall of the shell, and a filter element arranged in the shell; the filter element comprises an outer filter element and an inner filter element, the outer filter element comprises an outer filter layer, and the inner filter element comprises an inner filter layer; the outer filter layer comprises a gas-permeable waterproof layer, a coarse filter layer and an adsorption layer for adsorbing harmful gas; and the inner filter layer is a fine filter layer. The application can avoid waste caused by mismatched service life and simultaneous replacement, make it possible to perform back blowing maintenance on the fine filter layer, greatly prolong the overall service life and reduce the use cost. The application grasps the main contradiction, balances the waste target of the filter element and the target of structural complexity and maintenance complexity, and realizes the comprehensive target of improving the service life, reducing waste and not excessively increasing the structural complexity and maintenance complexity.

Description

Technical Field

[0001] This invention relates to an air filtration device for fuel cells. Background Technology

[0002] Proton exchange membrane fuel cell (PEMFC) vehicles have become an important direction for automotive development due to their zero emissions and high energy efficiency. Furthermore, due to their structural and operating principles, they produce no polluting gases during the electrochemical reaction process, exhibiting high output power and energy-saving and environmentally friendly characteristics. Currently, the application scenarios for these products in vehicles have expanded from urban roads to coal port areas and near-shore operations. The environmental indicators under different operating conditions vary significantly, requiring air filter devices to possess functions such as waterproofing, dustproofing, salt spray protection, and protection against harmful gases.

[0003] In the chemical reaction process of a fuel cell, the anode uses hydrogen as the fuel gas, and the cathode uses air as the oxidant. The reaction equation at the anode is H2 → 2H+ + 2e-. - Hydrogen ions move from a sulfonic acid group (-SO3H) to the cathode via the proton exchange membrane as hydrated protons H+ (XH2O). Electrons move to the cathode after doing work on the load via the external circuit. At the cathode, a reduction reaction occurs under the action of a catalyst. The reaction equation is: (1 / 2) O2 + 2H+ + 2e- - →H2O; The overall reaction equation is actually: H2 + (1 / 2)O2 →H2O.

[0004] The above is the basic principle of the redox reaction in fuel cells. Liquid pure hydrogen is currently commonly used to supply the anode, while the oxygen at the cathode is mainly supplied by the air. However, the air contains various pollutants, which will have a toxic effect on the fuel cell stack and affect its output power performance.

[0005] Studies have shown that the main air pollutants are particulate matter, SO2, and NO. X Therefore, the current design requirements for fuel cell air filters are that the air filtration device must have both the ability to filter particulate matter and the ability to adsorb harmful gases in order to ensure the normal and efficient operation of the fuel cell system.

[0006] The air filtration device includes a housing with an air inlet and an air outlet, and a filter element inside the housing. The filter element includes a filter layer and end caps. In the prior art, the filter element of the air filtration device for fuel cells is a single filter element, and its filter layer structure is... Figure 1 The multi-layered pleated structure or attached Figure 2The multi-layered winding structure shown is entirely cylindrical. Both of these structures integrate particulate matter filtration (layers) and harmful gas adsorption (layers), and both belong to the cylindrical filter element, radial air intake, and axial air exhaust structure, which is also the conventional technology for air filtration devices. Currently, air filtration devices for fuel cells both domestically and internationally adopt this structure.

[0007] In existing technologies, filter elements are all single-element filters. Some air filtration devices divide the filter element into a main filter element and a safety filter element. However, the division between the main filter element and the safety filter element is not based on the principle that one filters particulate matter and the other adsorbs harmful gases. This does not take into account the lifespan matching of filter layers that perform different functions, and cannot avoid wasting the filter element's lifespan. Rather, the main filter element performs its normal filtration function, and the safety filter element protects the engine when the main filter element fails. There is no difference between the two (main filter element and safety filter element) in terms of what they filter.

[0008] The inventor's research has broadened the knowledge of those skilled in the art, noting that there is a mismatch in service life between the filter layer that adsorbs harmful gases (hereinafter referred to as "adsorption filter layer") and the filter layer that filters particulate matter (hereinafter referred to as "filtration filter layer").

[0009] The shortcomings of existing air filtration devices for fuel cells, both domestically and internationally, lie in their use of a single filter element that adsorbs both harmful gases and filters particulate matter (including coarse and fine filtration). Because the lifespans of the adsorption and filtration layers are not synchronized, when the filter element that reaches the end of its lifespan needs replacement, the entire filter element, including both the adsorption and filtration layers, must be replaced. This results in wasted filter elements. Sometimes, adsorption or filtration layers that are far from reaching the end of their lifespan must be replaced together because the other layer needs replacement.

[0010] Innovation Explanation:

[0011] The inventiveness of this invention lies in the fact that the inventors have overcome the limitations of a single filter element by designing an outer filter element and an inner filter element, with the adsorption filter layer and the filtration filter layer arranged separately in the outer and inner filter elements. Essentially, it involves placing the filter layer for finely filtering particulate matter and the filter layer for adsorbing harmful gases separately in two filter elements connected in series in the gas path.

[0012] The significance of this improvement lies in the following: ① It allows for the separate replacement of the outer and inner filter elements, thus avoiding filter element waste; ② It also enables backflushing maintenance of the filter layer (fine filter layer) (previously, various filter layers such as adsorption filter layer and filtration filter layer were tightly integrated and could not be separated, making backflushing maintenance impossible); ③ Finally, the improvement approach of this invention also reflects the principle of addressing the main contradiction and balancing the goals of filter element waste with structural complexity and maintenance complexity.

[0013] These improvements and their significance are all proposed for the first time by the inventors and are not conventional technologies that those skilled in the art would normally encounter. In fact, existing technologies in the field of fuel cells use a single filter element, which essentially does not separate the filter layer for fine particulate matter and the filter layer for adsorbing harmful gases into two filter elements connected in series in the gas path. There is no teaching in the existing technology regarding the above-mentioned improvements and their technical significance.

[0014] The contradiction in the air filtration device of a fuel cell is not only the problem of the lifespan of the fine filter layer and the adsorption filter layer being often mismatched, but also the problem that the lifespans of each filter layer, such as the coarse filter layer, the adsorption filter layer, the coarse filter layer, and the waterproof layer, cannot be perfectly matched. The inventors grasped the main contradiction from the contradictory relationship caused by the multiple mismatches (a contradictory relationship that is not commonly encountered by those skilled in the art, and which is ignored in the solutions of existing technologies).

[0015] Coarse filter layers and waterproof filter layers typically have long lifespans and relatively low costs. Integrating the coarse filter layer, waterproof filter layer, and adsorption filter layer into an outer filter element avoids significant cost waste due to the relatively low cost of the coarse filter element and waterproof filter layer. It also avoids excessive structural complexity caused by too many filter elements (such as waterproof filter element, coarse filter element, adsorption filter element, and coarse filter element), which leads to excessive manufacturing costs and increases the complexity of installation, disassembly, and replacement operations. This results in excessive maintenance workload (if they are not replaced at the same time, only the filter element that reaches the end of its lifespan is replaced. The more filter elements there are, the higher the frequency of filter element replacement. Moreover, the large number of filter elements in the set makes the installation and disassembly operations troublesome). Summary of the Invention

[0016] The purpose of this invention is to provide a fuel cell air filtration device with a separately replaceable harmful gas filtration structure, which avoids the problem of filter waste by using an inner filter and an outer filter that are packaged together.

[0017] To achieve the above objectives, the fuel cell air filtration device of the present invention, which allows for the separate replacement of harmful gas filtration structures, includes a cylindrical housing, a maintenance end cap at one axial end of the housing, an air outlet at the other axial end of the housing, an air inlet connected to the circumferential side wall of the housing, and a cylindrical filter element inside the housing.

[0018] The filter element includes an outer filter element and an inner filter element, both of which are coaxially arranged with the housing. The ends of both the outer and inner filter elements facing the maintenance end cover are closed ends; the other ends of the outer and inner filter elements are opposite ends.

[0019] The outer filter element includes a cylindrical outer filter layer, and the closed end of the outer filter layer is connected to a first outer filter element end cap. The inner filter element includes a cylindrical inner filter layer, and the closed end of the inner filter layer is connected to a first inner filter element end cap. The outer filter element covers the inner filter element.

[0020] The opposite ends of the outer filter layer and the inner filter layer are connected to the axial end wall of the shell at the air outlet, and the central hole formed by the inner filter layer is connected to the air outlet.

[0021] An annular air intake chamber is formed between the outer filter layer and the inner wall of the housing, and the air inlet is connected to the air intake chamber;

[0022] The outer filter layer is used to filter water, coarsely filter particulate matter, and adsorb harmful gases. It has a multi-layer filter structure, including a breathable and waterproof layer for filtering water, a coarse filter layer for coarsely filtering particulate matter, and an adsorption layer for adsorbing harmful gases.

[0023] The inner filter layer is a fine filter layer used for fine filtration of particulate matter; in the gas flow path, the outer filter layer and the inner filter layer are connected in series and the outer filter layer is located upstream of the inner filter layer.

[0024] The outer filter layer is connected to a second outer filter element end cap at its opposite end, and the outer filter layer is connected to the axial end wall of the housing through the second outer filter element end cap;

[0025] The inner filter layer is connected to a second inner filter element end cap at its opposite end, and the inner filter layer is connected to the axial end wall of the housing through the second inner filter element end cap.

[0026] The inner surface of the axial end wall of the housing on the radially outer side of the air outlet is provided with an inner annular protrusion around the air outlet, and an outer annular protrusion is provided outside the inner annular protrusion. The centers of the inner annular protrusion and the outer annular protrusion are both located on the axis of the housing. The inner filter element is assembled between the inner annular protrusion and the outer annular protrusion, and the outer filter element is fitted on the outer annular protrusion.

[0027] The specific composition of the harmful gas adsorption layer is as follows: it includes a first support material layer, a first activated carbon layer bonded to the first support material layer by hot melt adhesive, a first resin layer bonded to the first activated carbon layer, a second activated carbon layer bonded to the first resin layer by hot melt adhesive, a second resin layer bonded to the second activated carbon layer, and a second support material layer bonded to the second resin layer by hot melt adhesive.

[0028] The specific composition of the harmful gas adsorption layer is as follows: it includes a first support material layer, a first activated carbon layer bonded to the first support material layer by hot melt adhesive, a second activated carbon layer bonded to the first activated carbon layer by hot melt adhesive, and a second support material layer bonded to the second activated carbon layer by hot melt adhesive.

[0029] The present invention has the following advantages:

[0030] Guided by the inventor's new understanding (that the lifespan of adsorption filter layers and filtration filter layers is usually mismatched, which seems easy to understand but is not the existing understanding), the filter element is a single cylindrical filter element divided into inner and outer cylindrical filter elements. The adsorption filter layer for harmful gases and the filtration filter layer for particulate matter are respectively set in the outer and inner filter elements. ① The outer and inner filter elements can be replaced separately, thus avoiding the waste of filter elements (filter media) caused by replacing them at the same time when their lifespans are mismatched, significantly extending the overall service life of the filter element, achieving more precise maintenance, and reducing operating costs. ② At the same time, the fine filter layer is set separately on the inner filter element, which also allows for backflushing maintenance of the fine filter layer, greatly extending its service life and further reducing its operating costs. This is also the meaning of "separately replaceable harmful gas filtration structure" in the title of this invention—because backflushing maintenance can greatly improve the service life of the fine filter layer, the harmful gas filtration structure can be replaced much more frequently than the fine filter element alone.

[0031] Finally, the contradiction in the air filtration device of a fuel cell not only lies in the often mismatched lifespans of the fine filter layer and the adsorption filter layer, but also in the fact that the lifespans of each filter layer, including the coarse filter layer, the adsorption filter layer, the coarse filter layer, and the waterproof layer, cannot be perfectly matched. The inventors, by identifying the primary contradiction amidst these multiple mismatches, demonstrated their ability to balance the goals of filter element waste with structural and maintenance complexity. These goals were proposed for the first time by the inventors and are not typical technical problems faced by those skilled in the art. Ultimately, this achieves a comprehensive goal of increasing lifespan, reducing filter material waste, and not excessively increasing structural and maintenance complexity.

[0032] Coarse filter layers and waterproof filter layers typically have long lifespans and relatively low costs. Integrating the coarse filter layer, waterproof filter layer, and adsorption filter layer into an external filter element avoids significant cost waste due to the relatively low cost of the coarse filter element and waterproof filter layer. It also avoids excessive structural complexity caused by too many filter elements (such as waterproof filter element, coarse filter element, adsorption filter element, and coarse filter element), which leads to excessive manufacturing costs and increased complexity in installation, disassembly, and replacement operations. This results in excessive maintenance workload (if they are not replaced at the same time, only the filter element that reaches the end of its lifespan is replaced, and the more filter elements there are, the higher the frequency of filter element replacement, and the more difficult the installation and disassembly operations are due to the large number of filter elements in the set). This achieves the goal of addressing the main contradiction and balancing the waste of filter elements with the structural complexity and maintenance complexity.

[0033] The second outer filter element end cap and the second inner filter element end cap enhance the integrity of the outer and inner filter elements, making installation, disassembly, and replacement easier.

[0034] The inner and outer annular protrusions provide assembly positioning functions, and as extensions of the housing, they increase the contact area between the housing and the inner and outer filter elements during assembly, thereby improving sealing performance. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the filter layer structure of an existing fuel cell air filtration device that uses a multi-layer pleated structure;

[0036] Figure 2 This is a schematic diagram of the filter layer structure of the filter element of an existing fuel cell air filtration device that uses a multi-layer winding structure;

[0037] Figure 3 This is an exploded structural diagram of the present invention after a sector-shaped column structure with a sector-shaped cross-section has been removed;

[0038] Figure 4 Cross-sectional view of a breathable waterproof layer or fine filter layer using a spiral winding structure;

[0039] Figure 5 This is a cross-sectional view when the breathable waterproof layer or fine filter layer adopts a single-layer rolled structure;

[0040] Figure 6 This is a partial structural diagram of the honeycomb-shaped filter media used in the coarse filter layer;

[0041] Figure 7 This is a partial structural diagram of the grid-type filter media used in the coarse filter layer;

[0042] Figure 8 This is a partial structural diagram of the porous filter media used in the coarse filter layer;

[0043] Figure 9 This is a schematic diagram of the layered structure of the adsorption layer under near-shore operating conditions, used in fuel cell air filtration devices for vehicles with applications including near-shore operating conditions.

[0044] Figure 10 This is a schematic diagram of the layered structure of the adsorption layer under non-shore operating conditions, used in fuel cell air filtration devices for vehicles whose application scenarios do not include offshore operating conditions.

[0045] Figure 11 This is a schematic diagram of the three-dimensional structure after a sector-shaped column structure with a sector-shaped cross-section has been removed according to the present invention;

[0046] Figure 12 This is a schematic diagram of the structure after removing a sector-shaped column structure with a sector-shaped cross-section according to the present invention;

[0047] Figure 13 yes Figure 12 AA sectional view. Detailed Implementation

[0048] like Figures 1 to 13 As shown, the fuel cell air filtration device of the present invention with a separately replaceable harmful gas filtration structure includes a cylindrical housing 1, a maintenance end cap 2 at one axial end of the housing 1, an air outlet 3 connected to the other axial end of the housing 1, an air inlet 4 connected to the circumferential side wall of the housing 1, and a cylindrical filter element inside the housing 1.

[0049] The filter element includes an outer filter element and an inner filter element, both of which are coaxially arranged with the housing 1. The ends of the outer filter element and the inner filter element facing the maintenance end cover 2 are closed ends; the other ends of the outer filter element and the inner filter element are opposite ends (adjacent to the air outlet 3).

[0050] The outer filter element includes a cylindrical outer filter layer, and the closed end of the outer filter layer (bonded with PU adhesive) is connected to a first outer filter element end cap 5 (preferably a PU end cap). The inner filter element includes a cylindrical inner filter layer, and the closed end of the inner filter layer (bonded with PU adhesive) is connected to a first inner filter element end cap 6 (preferably a PU end cap). The outer filter element covers the inner filter element.

[0051] The opposite ends of the outer filter layer and the inner filter layer are connected to the axial end wall of the housing 1 at the air outlet 3 (such as by bonding), and the central hole formed by the inner filter layer is connected to the air outlet 3.

[0052] An annular air intake chamber 7 is formed between the outer filter layer and the inner wall of the housing 1, and the air inlet 4 communicates with the air intake chamber 7;

[0053] The outer filter layer is used to filter water, coarsely filter particulate matter and adsorb harmful gases. It has a multi-layer filter structure, which includes a breathable and waterproof layer 8 for filtering water, a coarse filter layer 9 for coarsely filtering particulate matter and an adsorption layer 10 for adsorbing harmful gases from the radial outside to the radial inside.

[0054] The inner filter layer is a fine filter layer 11 used for fine filtration of particulate matter; in the gas flow path, the outer filter layer and the inner filter layer are connected in series and the outer filter layer is located upstream of the inner filter layer.

[0055] Guided by the inventor's new understanding (that the lifespan of adsorption and filtration layers is often mismatched, which seems easy to understand but is not a current understanding), the filter element is a single cylindrical element divided into inner and outer cylindrical elements. The adsorption and filtration layers are respectively placed in the outer and inner filter elements. ① This allows for separate replacement of the outer and inner filter elements, avoiding the waste caused by replacing them simultaneously when their lifespans are mismatched, significantly extending the overall lifespan of the filter element, enabling more precise maintenance, and reducing operating costs. ② Simultaneously, the fine filtration layer 11 is separately located on the inner filter element, allowing for backflushing maintenance of the fine filtration layer 11, greatly extending its lifespan, and further reducing its operating costs.

[0056] Finally, the contradiction in the air filtration device of the fuel cell not only involves the mismatch between the lifespan of the fine filter layer 11 and the adsorption filter layer, but also the fact that the lifespans of each filter layer, including the coarse filter layer 9, the adsorption filter layer, and the waterproof layer, cannot be perfectly matched. The inventors have grasped the main contradiction from these multiple mismatches, demonstrating their ability to address the core issue and balance the goals of filter element waste with structural and maintenance complexity. These goals are unprecedented for the inventors and are not typical technical problems encountered by those skilled in the art.

[0057] Coarse filter layers and waterproof filter layers typically have long lifespans and relatively low costs. Integrating the coarse filter layer, waterproof filter layer, and adsorption filter layer into an external filter element avoids significant cost waste due to the relatively low cost of the coarse filter element and waterproof filter layer. It also avoids excessive structural complexity caused by too many filter elements (such as waterproof filter element, coarse filter element, adsorption filter element, and coarse filter element), which leads to excessive manufacturing costs and increased complexity in installation, disassembly, and replacement operations. This results in excessive maintenance workload (if they are not replaced at the same time, only the filter element that reaches the end of its lifespan is replaced, and the more filter elements there are, the higher the frequency of filter element replacement, and the more difficult the installation and disassembly operations are due to the large number of filter elements in the set). This achieves the goal of addressing the main contradiction and balancing the waste of filter elements with the structural complexity and maintenance complexity.

[0058] Among them, the breathable and waterproof layer 8, the coarse filter layer 9, and the fine filter layer 11 are all conventional technologies and will not be described in detail. The breathable and waterproof layer 8 uses existing breathable and waterproof materials. Its working principle is that because liquid water particles have a large radius, there is surface tension on the surface of the water droplets (water molecules "pull and resist" each other), which prevents liquid water molecules from easily detaching to the downstream of the waterproof and breathable layer. The application of waterproof and breathable materials in air filtration devices is as follows: Figure 4 The spiral winding structure shown or Figure 5 The single-layer rolled structure shown.

[0059] The coarse filter layer 9 is a porous filtration structure that uses physical interception to filter particulate impurities larger than the pore size. Its porous structure consists of the following forms: The filter material used in the coarse filter layer 9 can be... Figure 6 The honeycomb-shaped filter material shown can also be Figure 7 The grid-type filter media shown can also be Figure 8 The porous filter media shown are not limited to these three structures; the connection methods between the coarse filter layer 9 and the breathable and waterproof layer 8, the adsorption layer 10, the outer end cap and the shell 1 include, but are not limited to, bonding, injection molding, embedding and welding.

[0060] The harmful gas adsorption layer 10 is composed of a supporting material (which can be various breathable materials, such as PET or metal mesh), hot melt adhesive, activated carbon, and resin. In near-shore operating conditions, the adsorption layer 10 material includes resin; in non-near-shore operating conditions, the adsorption layer 10 material does not include resin. If a vehicle is sometimes used near-shore and sometimes offshore, it is treated as a near-shore operating condition vehicle. In this case, the adsorption layer 10 of the external filter element of the fuel cell air filter installed in the vehicle will include resin to adsorb salt spray ions under near-shore operating conditions. Figure 9 The diagram shows the layered structure of the adsorption layer 10 under near-shore conditions. Figure 10 This is a schematic diagram of the layered structure of the adsorption layer 10 under non-shore operating conditions. Based on the principles of resin use described above, the adsorption layer 10 can be designed with other layered structures.

[0061] The fine filter layer 11 has a filtration precision of 0.3 micrometers, and its filtration efficiency for particles larger than 0.3 micrometers is over 99%. The filter layer is composed of any two or three of the following: high-precision glass fiber, electrostatic non-woven fabric, and nanofiber filter paper. It filters and intercepts dust particles based on physical interception or electrostatic adsorption principles. The cross-sectional structure of the high-precision filter layer can be as follows: Figure 4 The spiral winding structure shown can also be Figure 5 The single-layer rolled structure shown.

[0062] The outer filter layer is connected to the opposite end of the second outer filter element end cap 12, and the outer filter layer is connected to the axial end wall of the housing 1 through the second outer filter element end cap 12;

[0063] The inner filter layer is connected to the opposite end of the second inner filter element end cap 13, and the inner filter layer is connected to the axial end wall of the housing 1 through the second inner filter element end cap 13.

[0064] The second outer filter element end cap 12 and the second inner filter element end cap 13 enhance the integrity of the outer and inner filter elements, making installation, disassembly, and replacement convenient.

[0065] An inner annular protrusion 14 is provided on the inner surface of the axial end wall of the housing 1 on the radially outer side of the air outlet 3, and an outer annular protrusion 15 is provided outside the inner annular protrusion 14. The centers of the inner annular protrusion 14 and the outer annular protrusion 15 are both located on the axis of the housing 1. The inner filter element is assembled between the inner annular protrusion 14 and the outer annular protrusion 15, and the outer filter element is fitted on the outer annular protrusion 15 (outer).

[0066] The inner annular protrusion 14 and the outer annular protrusion 15 provide assembly positioning functions, and as extensions of the housing 1, the inner annular protrusion 14 and the outer annular protrusion 15 increase the contact area between the housing 1 and the inner and outer filter elements during assembly, thereby improving sealing performance.

[0067] In use, the fuel cell air filter device of this invention, with its separately replaceable harmful gas filter structure, is installed on a motor vehicle. When the vehicle's operating environment has few harmful gases but many particulate matter, the inner filter element bears a greater load; when the operating environment has many harmful gases but few particulate matter, the outer filter element bears a greater load. When either the outer or inner filter element needs replacement, since the outer and inner filter elements are separately configured in this invention, they can be connected to or removed from the housing 1 respectively. Only the filter element that needs replacement or maintenance is removed for maintenance or replacement, without the need for a complete replacement of the entire filter element. During use, the service life of the inner filter element can be extended by backflushing the fine filter layer 11.

[0068] Example 1

[0069] like Figure 9 As shown, the specific structure of the harmful gas adsorption layer 10 in this embodiment is as follows: it includes a first support material layer 16 (made of PET material or metal mesh), a first activated carbon layer 17 is bonded to the first support material layer 16 by hot melt adhesive 22, a first resin layer 18 is bonded to the first activated carbon layer 17, a second activated carbon layer 19 is bonded to the first resin layer 18 by hot melt adhesive 22, a second resin layer 20 is bonded to the second activated carbon layer 19, and a second support material layer 21 is bonded to the second resin layer 20 by hot melt adhesive 22.

[0070] In this embodiment, the adsorption layer 10 can adsorb salt spray, making it suitable for near-shore operations.

[0071] Example 2

[0072] like Figure 10 As shown, the specific structure of the harmful gas adsorption layer 10 in this embodiment is as follows: it includes a first support material layer 16 (made of PET material or metal mesh), a first activated carbon layer 17 is bonded to the first support material layer 16 by hot melt adhesive 22, a second activated carbon layer 19 is bonded to the first activated carbon layer 17 by hot melt adhesive 22, and a second support material layer 21 is bonded to the second activated carbon layer 19 by hot melt adhesive 22.

[0073] In this embodiment, the adsorption layer 10 may not be designed for salt spray and is suitable for non-coastal areas without salt spray.

[0074] The above embodiments are only used to illustrate and not limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention without departing from the spirit and scope of the present invention. Any modifications or partial substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A fuel cell air filter device with a separately replaceable harmful gas filter structure, comprising a cylindrical housing, a maintenance end cap at one axial end of the housing, an air outlet connected to the other axial end of the housing, an air inlet connected to the circumferential side wall of the housing, and a cylindrical filter element disposed inside the housing; characterized in that: The filter element includes an outer filter element and an inner filter element, both of which are coaxially arranged with the housing. The ends of both the outer and inner filter elements facing the maintenance end cover are closed ends; the other ends of the outer and inner filter elements are opposite ends. The outer filter element includes a cylindrical outer filter layer, and the closed end of the outer filter layer is connected to a first outer filter element end cap. The inner filter element includes a cylindrical inner filter layer, and the closed end of the inner filter layer is connected to a first inner filter element end cap. The outer filter element covers the inner filter element. The opposite ends of the outer filter layer and the inner filter layer are connected to the axial end wall of the shell at the air outlet, and the central hole formed by the inner filter layer is connected to the air outlet. An annular air intake chamber is formed between the outer filter layer and the inner wall of the housing, and the air inlet communicates with the air intake chamber; The outer filter layer is used to filter water, coarsely filter particulate matter, and adsorb harmful gases. It has a multi-layer filter structure, which includes, from the radial outside to the radial inside, a breathable and waterproof layer for filtering water, a coarse filter layer for coarsely filtering particulate matter, and an adsorption layer for adsorbing harmful gases. The inner filter layer is a fine filter layer used for fine filtration of particulate matter; in the gas flow path, the outer filter layer and the inner filter layer are connected in series and the outer filter layer is located upstream of the inner filter layer.

2. The fuel cell air filtration device with a separately replaceable harmful gas filter structure according to claim 1, characterized in that: The outer filter layer is connected to a second outer filter element end cap at its opposite end, and the outer filter layer is connected to the axial end wall of the housing through the second outer filter element end cap; The inner filter layer is connected to a second inner filter element end cap at its opposite end, and the inner filter layer is connected to the axial end wall of the housing through the second inner filter element end cap.

3. The fuel cell air filtration device with a separately replaceable harmful gas filter structure according to claim 1 or 2, characterized in that: The inner surface of the axial end wall of the housing on the radially outer side of the air outlet is provided with an inner annular protrusion around the air outlet, and an outer annular protrusion is provided outside the inner annular protrusion. The centers of the inner annular protrusion and the outer annular protrusion are both located on the axis of the housing. The inner filter element is assembled between the inner annular protrusion and the outer annular protrusion, and the outer filter element is fitted on the outer annular protrusion.

4. The fuel cell air filtration device with a separately replaceable harmful gas filter structure according to claim 3, characterized in that: The specific composition of the harmful gas adsorption layer is as follows: it includes a first support material layer, a first activated carbon layer bonded to the first support material layer by hot melt adhesive, a first resin layer bonded to the first activated carbon layer, a second activated carbon layer bonded to the first resin layer by hot melt adhesive, a second resin layer bonded to the second activated carbon layer, and a second support material layer bonded to the second resin layer by hot melt adhesive.

5. The fuel cell air filtration device with a separately replaceable harmful gas filter structure according to claim 3, characterized in that: The specific composition of the harmful gas adsorption layer is as follows: it includes a first support material layer, a first activated carbon layer bonded to the first support material layer by hot melt adhesive, a second activated carbon layer bonded to the first activated carbon layer by hot melt adhesive, and a second support material layer bonded to the second activated carbon layer by hot melt adhesive.

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