Exhaust system for hydrogen fuel cell vehicle

Abstract

An exhaust system (50) for a hydrogen fuel cell vehicle includes: a housing (71) including at least one discharge hole (9) provided in a lower portion of the housing (71) and configured to discharge water; a water separator (5) integrated in the housing (71) and configured to separate water from the exhaust gas; and a muffler (60) integrated in the housing (71) and disposed downstream of the water separator (5), the muffler (60) comprising a cylindrical tube body (7) comprising a grille side wall and a sound absorbing material (6) circumferentially wrapped around the grille side wall.

Description

Technical Field

[0001] Embodiments relate to hydrogen fuel cell vehicles, and more particularly to exhaust systems for hydrogen fuel cell vehicles. Background Art

[0002] Generally speaking, fuel cells generate electricity through the electrochemical reaction of hydrogen fuel and oxygen. Due to the increasing demand for alternative power sources, fuel cells have been researched and developed as a power supply. As a truly "zero-emission, pollution-free" energy source, hydrogen fuel cells are one of the main development directions of future clean energy.

[0003] A fuel cell includes a fuel cell stack for generating electrical energy, a fuel supply system for supplying fuel (hydrogen) to the fuel cell stack, an air supply system for supplying air to the fuel cell stack, and related components. Furthermore, the fuel cell is provided with an exhaust system configured to discharge exhaust gases comprising air and water. Fuel cells generate high-frequency noise, such as the sound of high-speed air flow, so a muffler is installed in the exhaust system to reduce the noise. The muffler includes a sound-absorbing material, such as glass wool, sound-absorbing cotton, or the like, to reduce the noise.

[0004] The exhaust gas produced by the reaction of hydrogen and oxygen in fuel cells contains a large amount of water and moisture. In particular, moisture condenses in the muffler, or water condensed in the upstream exhaust system is introduced into the muffler, which often causes water to accumulate at the bottom of the muffler. At the same time, because the muffler includes sound-absorbing materials with very high hydration properties, the muffler easily absorbs water and moisture. As a result, the muffler may not always maintain its intended sound absorption capacity, and its acoustic performance may degrade. In addition, in ambient conditions with temperatures below 0°C, water may freeze, leading to problems such as degraded exhaust performance.

[0005] Currently, exhaust systems for hydrogen fuel cell vehicles have limited water separation efficiency and are therefore unable to effectively separate and expel liquid water from the exhaust gas.

[0006] To this end, it is desirable to develop an exhaust system for hydrogen fuel cell vehicles that will effectively separate water from the exhaust gas. Summary of the Invention

[0007] An object of the present invention is to provide an exhaust system for a hydrogen fuel cell vehicle that will effectively separate water from the exhaust gas.

[0008] Another object of the present invention is to provide an exhaust system for a hydrogen fuel cell vehicle that will exhibit optimized flow properties.

[0009] In one aspect, an exhaust system for a hydrogen fuel cell vehicle is provided. The exhaust system comprises:

[0010] a housing provided with at least one drain hole disposed in a lower portion of the housing and configured to drain water;

[0011] a water separator integrated in the housing and configured to separate water from the exhaust gas; and

[0012] The muffler is integrated in the housing and arranged downstream of the water separator. The muffler includes a cylindrical pipe body including a grid side wall and a sound absorbing material circumferentially wrapped around the grid side wall.

[0013] The water separator may include a first cylindrical portion proximate the inlet of the exhaust system and a second conical portion proximate the muffler, the inner diameter of the second conical portion increasing in a downstream direction.

[0014] The first cylindrical portion may be provided with at least one helical guide blade configured to cause the exhaust gas to rotate in a vortex manner to generate centrifugal force to separate water from the exhaust gas, and the second conical portion (52) may be configured to facilitate throwing the water onto the inner surface of the housing.

[0015] The muffler may further include a guide fitting at the upstream end of the cylindrical pipe body.

[0016] The guide fitting may include a cylindrical outer surface and a cylindrical inner surface, the cylindrical body defining a muffler inner diameter Dm, and the cylindrical inner surface defining an inner diameter Din equal to the muffler inner diameter Dm.

[0017] The guide fitting may include a cylindrical outer surface and a conical inner surface, wherein the cylindrical body defines a muffler inner diameter Dm, and the conical inner surface defines an inlet inner diameter Din at its upstream end and an outlet inner diameter at its downstream end. The inlet inner diameter Din may be greater than the muffler inner diameter Dm, and the outlet inner diameter may be equal to the muffler inner diameter Dm.

[0018] The muffler inner diameter Dm may be between 60% and 90% of the inlet inner diameter Din.

[0019] The guide fitting may comprise a length L in the longitudinal direction of the exhaust system, which may be between 10% and 50% of the muffler inner diameter Dm.

[0020] The cylindrical tubular body may be provided with a plurality of annular support walls extending outwardly from an outer surface of the cylindrical tubular body and configured to support the muffler in the housing.

[0021] The cylindrical pipe body may be provided with at least one partition extending inwardly from an inner surface of the cylindrical pipe body and configured to divide the inner cavity into a plurality of resonance cavities along a longitudinal direction of the exhaust system.

[0022] The water separator may be provided with a plurality of annular support walls extending outwardly from an outer surface of the water separator and configured to support the water separator in the housing.

[0023] The at least one drain hole may be provided in the housing at a position adjacent to and downstream of the water separator.

[0024] The guide fitting and the cylindrical pipe body may be integrated into one piece, and the water separator, the guide fitting and the cylindrical pipe body may be formed of polypropylene.

[0025] A valve may be disposed in the at least one discharge hole and configured to control the discharge of water.

[0026] The sound absorbing material may be provided with a waterproof coating on its outside.

[0027] The water separator integrated upstream of the muffler effectively separates water from the exhaust gas, allowing the muffler to maintain its intended sound absorption capacity, resulting in excellent acoustic performance. The muffler contains one or more separate resonance chambers to meet the noise reduction requirements.

[0028] In addition, the water separator is a centrifugal water separator, which does not require an external electric power supply source to generate centrifugal force, thereby saving operating costs.

[0029] Furthermore, with a waterproof coating on the outside of the sound-absorbing material, the muffler can always maintain its intended sound absorption capabilities.

[0030] The main material of the exhaust system is polypropylene (PP) plastic, which is easier to integrate with other plastic structures than traditional metal exhaust systems, is lightweight, low-cost, and will not rust.

[0031] The sound damping performance is optimized by optimizing the flow characteristics in the muffler using guide fittings.

[0032] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present disclosure will be more fully understood from the detailed description and accompanying drawings.

[0034] Figure 1 is a schematic diagram of an example fuel cell system according to an embodiment.

[0035] Figure 2 is a schematic exploded diagram of an example exhaust system of a fuel cell system according to an embodiment.

[0036] Figure 3 Schematically illustrates a flow field state of a combination of a water separator and a muffler of a fuel cell system according to an embodiment.

[0037] Figure 4 is a schematic diagram of an example of a combination of a water separator and a muffler without optimizing a 3D effect according to an embodiment, with the housing removed.

[0038] Figure 5 is a schematic diagram of an example of a combination of a water separator and a resonator with optimized 3D effect according to an embodiment, with the housing removed.

[0039] Figure 6 Shown Figure 4 The combination of water resonator and muffler and Figure 5 Sound damping properties of the combination of a water resonator and a muffler. DETAILED DESCRIPTION

[0040] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate similar or corresponding parts and features. In addition, the drawings are generally schematic and not necessarily drawn to scale. Some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to use the present disclosure in various ways.

[0041] Certain terms may be used in the following description for reference purposes only and are not intended to be limiting. For example, terms such as "above" and "below" refer to directions in the drawings to which reference is made. Terms such as "front," "back," "front," "back," "left," "right," "rear," "side," "up," "down," "top," and "bottom" describe the orientation and / or position of parts of a component or element within a consistent but arbitrary reference frame, which becomes clear by reference to the text and associated drawings describing the component or element in question.

[0042] In addition, terms such as "first," "second," and "third" may be used to describe individual components. Such terms are used to describe the drawings and are not intended to limit the scope of the present disclosure as defined by the appended claims. Furthermore, the teachings may be described herein in terms of functional and / or logical block components and / or various processing steps. It should be understood that such block components may include multiple hardware, software, and / or firmware components configured to perform the specified functions.

[0043] As used herein, the terms “downstream” or “upstream” may be used to indicate a direction relative to the direction of exhaust gas flow.

[0044] Reference is now made to the drawings, wherein like reference numerals refer to like features throughout the several views. Figure 1 is a schematic diagram of a fuel cell system 100 according to an embodiment; Figure 2 is a schematic exploded view of the structure of the fuel cell system 100 according to the embodiment.

[0045] Figure 1 is a schematic diagram of an example fuel cell system 100 according to an embodiment. Figure 1 The fuel cell system 100 may include a hydrogen supply unit 20 , a fuel cell stack 30 , an air supply unit 40 , and an exhaust system 50 .

[0046] The hydrogen supply unit 20 can supply hydrogen from the hydrogen tank to the fuel cell stack 30 according to the operating conditions of the fuel cell stack 30. After the chemical reaction occurs in the fuel cell stack 30, the remaining hydrogen can be discharged through the outlet of the hydrogen electrode (anode) of the fuel cell stack 30 or recycled to the inlet of the hydrogen electrode of the fuel cell stack 30 through a hydrogen recycling device (not shown).

[0047] The fuel cell stack 30 can generate electrical energy by an electrochemical reaction between hydrogen fuel and air containing oxygen. The fuel cell stack 30 may include a plurality of fuel cells and a plurality of separators stacked alternately. Each fuel cell may include a cathode, an electrolyte layer and an anode. For example, the hydrogen supplied to the anode may be separated into hydrogen ions and electrons, the electrons may move to the cathode, and at the cathode, oxygen may combine with the electrons to produce oxygen ions. The oxygen ions may move to the anode through the electrolyte layer and combine with the hydrogen ions at the anode to produce a reactant, i.e., water. The fuel cell stack 30 may include a polymer electrolyte membrane fuel cell (PEMFC), a phosphoric acid fuel cell (PAFC), an alkaline fuel cell (AFC), a molten carbonate fuel cell (MCFC), a solid oxide fuel cell (SOFC), etc., without departing from the scope of the present disclosure.

[0048] The fuel cell stack 30 may include a purge valve (not shown) to discharge hydrogen from the hydrogen electrode of the fuel cell stack 30. The purge valve can be opened or closed at a predetermined purge interval. In addition, a sensor (not shown) can be provided at the outlet of the anode of the fuel cell stack 30. The sensor (not shown) can measure the pressure and concentration of the hydrogen introduced into the fuel cell stack 30 and the hydrogen discharged from the fuel cell stack after the reaction. It should be understood by those skilled in the art that the fuel cell stack 30 may include other components, such as a controller, etc., as needed without departing from the scope of the present disclosure.

[0049] The air supply unit 40 can supply air to the fuel cell stack 30. The fuel cell system 100 can be used in vehicles, including but not limited to passenger vehicles, sport utility vehicles, light trucks, heavy vehicles, minivans, buses, delivery vehicles, bicycles, mobile robots, agricultural equipment (such as tractors), sports-related equipment (such as golf carts), and trains. It should be understood by those skilled in the art that the fuel cell system 100 can be used in any other movable or fixed platform, such as an excavator, a compressor, a robot, etc., without departing from the scope of the present disclosure.

[0050] Figure 2 is a schematic exploded view of an example exhaust system of a fuel cell system according to an embodiment. The exhaust system 50 may include a housing 71 provided with at least one exhaust hole 9, the at least one exhaust hole 9 being provided in a lower portion of the housing 71 and configured to discharge water. Figure 2 As shown in FIG, the housing 71 includes an upper cover 4 and a lower housing 10. At least one drain hole 9 is provided at the bottom of the lower housing 10, near the water separator 5 and downstream of the water separator 5. A valve (not shown) may be provided in the at least one drain hole 9 and configured to control the discharge of water. It will be understood by those skilled in the art that the housing 71 may have other suitable structures without departing from the scope of the present disclosure.

[0051] The exhaust system 50 may further include a water separator 5 that is integrated in the housing 71 and configured to separate water from the exhaust gas. The exhaust system 50 may further include a muffler 60 that is integrated in the housing 71 and disposed downstream of the water separator 5. Figure 2 As shown in FIG, the muffler 60 includes a cylindrical pipe body 7 including a grid sidewall and a sound absorbing material 6 circumferentially wrapped around the grid sidewall. It should be understood by those skilled in the art that the muffler 60 may have other suitable structures without departing from the scope of the present disclosure.

[0052] The exhaust system 50 may further include a suitable connection structure, such as a first connection adapter 1, an inlet pipe 2, a second connection adapter 3, a third connection adapter 11, and an outlet pipe 12. Those skilled in the art will appreciate that the exhaust system 50 may include any other suitable components without departing from the scope of the present disclosure.

[0053] Figure 3The flow field state of the combination of the water separator 5 and the muffler 60 of the fuel cell system 100 according to the embodiment is schematically shown. The exhaust gas containing water and moisture (as shown in the star shape) first flows into the water separator 5. The water separator 5 causes the exhaust gas to rotate in a vortex manner under the action of the blades 54 to generate centrifugal force to separate water from the exhaust gas and throw the water (as shown in the rectangular shape) to the inner wall of the water separator 5. The water continues to rotate along the inner wall and is finally thrown out of the water separator to reach the inner wall of the shell 71. The separated water gathers in the lower part of the shell 71 and is discharged through the discharge hole 9 at the bottom of the shell 71. The exhaust gas from which the water has been separated flows into the muffler 60, and the noise is attenuated by the sound absorbing material in the muffler 60 and the muffler 60 itself.

[0054] By effectively separating water from the exhaust gas through the centrifugal water separator 5 integrated upstream of the muffler 60 , the muffler 60 can always maintain its intended sound absorption capability, thereby achieving excellent acoustic performance.

[0055] In addition, the water separator 5 is shown as a centrifugal water separator, which does not require an external electrical power supply to generate centrifugal force, thereby saving operating costs. However, it will be understood by those skilled in the art that the water separator 5 may also be of any other suitable type, such as a membrane, without departing from the scope of this disclosure.

[0056] like Figure 2 As shown in , the muffler 60 is provided with a plurality of annular support walls 14 extending outwardly from the outer surface of the muffler 60 and configured to support the muffler 60 in the housing 71. Similarly, the water separator 5 is provided with a plurality of annular support walls 13 extending outwardly from the outer surface of the water separator 5 and configured to support the water separator 5 in the housing 71.

[0057] In addition, the muffler 60 is further provided with at least one partition 8 extending inwardly from the inner surface of the muffler 60 and configured to divide the inner cavity into a plurality of resonance cavities along the longitudinal direction of the exhaust system 50 to meet the noise reduction requirements.

[0058] According to one example, the sound absorbing material 6 is provided with a waterproof coating (not shown) on its outer side. By the waterproof coating on the outer side of the sound absorbing material, the muffler can always maintain its expected sound absorbing capability.

[0059] Figure 4 : is a schematic diagram of an example of a combination of a water separator 5 and a muffler 60 without optimizing a 3D effect according to an embodiment, wherein the housing 71 is removed. Figure 4As shown in FIG, the water separator 5 comprises a first cylindrical portion 51 near the inlet of the exhaust system 50 and a second conical portion 52 near the muffler 60, the inner diameter of the second conical portion 52 increasing in the downstream direction. The first cylindrical portion 51 is provided with at least one spiral guide blade 54 (such as Figure 3 ), is configured to cause the exhaust gas to rotate in a vortex manner to generate centrifugal force to separate water from the exhaust gas, and the second tapered portion 52 is configured to facilitate throwing water onto the inner surface of the shell 71. In addition, the muffler 60 further includes a guide fitting 53 located at the upstream end of the cylindrical pipe body 7.

[0060] According to one example, the guide fitting 53 may include a cylindrical outer surface and a cylindrical inner surface. The cylindrical pipe body 7 defines an inner diameter Dm of the muffler, and the cylindrical inner surface of the guide fitting 53 defines an inner diameter Din equal to the inner diameter Dm of the muffler.

[0061] According to one example, the guide fitting 53 and the cylindrical tube 7 are integrated into one piece, and the water separator 5, the guide fitting 53, and the cylindrical tube 7 are formed from polypropylene. The primary material of the exhaust system is polypropylene (PP), which is easier to integrate with other plastic structures than traditional metal exhaust systems, is lightweight, low-cost, and rust-resistant. However, those skilled in the art will appreciate that the water separator 5, the guide fitting 53, and the cylindrical tube 7 can be made of any other suitable material, such as steel or other plastic materials, without departing from the scope of this disclosure.

[0062] Figure 5 : is a schematic diagram of an example of a combination of a water separator 5 and a muffler 60 with an optimized 3D effect according to an embodiment, wherein the housing 71 is removed. Figure 5 As shown in FIG, the water separator 5 comprises a first cylindrical portion 51 near the inlet of the exhaust system 50 and a second conical portion 52 near the muffler 60, the inner diameter of the second conical portion 52 increasing in the downstream direction. The first cylindrical portion 51 is provided with at least one spiral guide blade 54 (such as Figure 3 ), is configured to cause the exhaust gas to rotate in a vortex manner to generate centrifugal force to separate water from the exhaust gas, and the second tapered portion 52 is configured to facilitate throwing water onto the inner surface of the shell 71. In addition, the muffler 60 further includes a guide fitting 53 located at the upstream end of the cylindrical pipe body 7.

[0063] like Figure 5As shown in FIG, guide fitting 53 includes a cylindrical outer surface and a tapered inner surface. The cylindrical tube body 7 defines a muffler inner diameter Dm. The tapered inner surface defines an inlet inner diameter Din at its upstream end and an outlet inner diameter at its downstream end. The inlet inner diameter Din is greater than the muffler inner diameter Dm, while the outlet inner diameter is equal to the muffler inner diameter Dm. According to one example, the muffler inner diameter Dm is between 60% and 90% of the inlet inner diameter Din.

[0064] According to one example, the guide fitting 53 and the cylindrical tube 7 are integrated into one piece, and the water separator 5, the guide fitting 53, and the cylindrical tube 7 are formed from polypropylene. The primary material of the exhaust system is polypropylene (PP), which is easier to integrate with other plastic structures than traditional metal exhaust systems, is lightweight, low-cost, and rust-resistant. However, those skilled in the art will appreciate that the water separator 5, the guide fitting 53, and the cylindrical tube 7 can be made of any other suitable material, such as steel or other plastic materials, without departing from the scope of this disclosure.

[0065] like Figure 5 As shown in FIG, the guide fitting 53 comprises a length L in the longitudinal direction of the exhaust system 50. According to one example, the length L is between 10% and 50% of the muffler inner diameter Dm.

[0066] Figure 6 Shown Figure 4 The combination of the water separator 5 and the muffler 60 and Figure 5 The sound damping properties of the combination of the water separator 5 and the muffler 60. Figure 6 It can be seen that the optimized 3D effect Figure 5 The exhaust system is 50% better than that without 3D optimization Figure 4 The exhaust system 50 exhibits better sound damping characteristics. By optimizing the flow characteristics in the muffler 60 using the guide fitting 53, the sound damping performance is optimized.

[0067] Various aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; however, those skilled in the art will recognize that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise construction and compositions disclosed herein; any and all modifications, variations, and variations apparent from the foregoing description are within the scope of the present disclosure as defined by the appended claims. Furthermore, the present concept expressly encompasses any and all combinations and subcombinations of the foregoing elements and features.

Claims

1. An exhaust system (50) for a hydrogen fuel cell vehicle, the exhaust system (50) comprising: a housing (71) comprising at least one discharge hole (9) disposed in a lower portion of the housing (71) and configured to discharge water; a water separator (5) integrated in the housing (71) and configured to separate water from the exhaust gas; and The muffler (60) is integrated in the housing (71) and arranged downstream of the water separator (5). The muffler (60) comprises a cylindrical pipe body (7) comprising a grille side wall and a sound absorbing material (6) circumferentially wrapped around the grille side wall.

2. The exhaust system (50) according to claim 1, wherein The water separator (5) comprises a first cylindrical portion (51) close to the inlet of the exhaust system (50) and a second conical portion (52) close to the muffler (60), the inner diameter of the second conical portion (52) increasing in a downstream direction.

3. The exhaust system (50) according to claim 2, wherein: The first cylindrical portion (51) includes at least one helical guide blade (54) configured to cause the exhaust gas to rotate in a vortex manner to generate centrifugal force to separate water from the exhaust gas, and The second tapered portion (52) is configured to facilitate throwing water onto the inner surface of the housing (71).

4. The exhaust system (50) according to claim 3, wherein: The muffler (60) further comprises a guide fitting (53) located at the upstream end of the cylindrical pipe body (7).

5. The exhaust system (50) according to claim 4, wherein: The guide fitting (53) comprises a cylindrical outer surface and a cylindrical inner surface, The cylindrical tube (7) has a muffler inner diameter Dm, and The cylindrical inner surface has an inner diameter Din equal to the inner diameter Dm of the muffler.

6. The exhaust system (50) according to claim 4, wherein: The guide fitting (53) comprises a cylindrical outer surface and a conical inner surface, The cylindrical tube (7) has a muffler inner diameter Dm, and The conical inner surface has an inlet inner diameter Din at its upstream end and an outlet inner diameter at its downstream end, wherein the inlet inner diameter Din is larger than the muffler inner diameter Dm and the outlet inner diameter is equal to the muffler inner diameter Dm.

7. The exhaust system (50) according to claim 6, wherein: The muffler inner diameter Dm is between 60% and 90% of the inlet inner diameter Din.

8. The exhaust system (50) according to claim 7, wherein: The guide fitting (53) has a length L in the longitudinal direction of the exhaust system (50), and the length L is between 10% and 50% of the inner diameter Dm of the muffler.

9. The exhaust system (50) according to any one of claims 1 to 8, wherein: The cylindrical pipe body (7) further comprises a plurality of annular support walls (14) extending outwardly from an outer surface of the cylindrical pipe body (7) and configured to support the muffler (60) in the housing (71).

10. The exhaust system (50) according to any one of claims 1 to 9, wherein: The cylindrical pipe body (7) further comprises at least one partition (8) extending inward from the inner surface of the cylindrical pipe body (7) and configured to divide the inner cavity into a plurality of resonance cavities along the longitudinal direction of the exhaust system (50).

11. The exhaust system (50) according to any one of claims 1 to 10, wherein: The water separator (5) includes a plurality of annular support walls (13) extending outwardly from an outer surface of the water separator (5) and configured to support the water separator (5) in the housing (71).

12. The exhaust system (50) according to any one of claims 1 to 11, wherein: The at least one discharge hole (9) is provided in the housing (71) at a position close to the water separator (5) and downstream of the water separator (5).

13. The exhaust system (50) according to any one of claims 4 to 8, wherein: The guide fitting (53) and the cylindrical tube (7) are integrated into one piece, and The water separator (5), the guide fitting (53) and the cylindrical tube body (7) are formed from polypropylene.

14. The exhaust system (50) according to any one of claims 1 to 13, wherein: The at least one discharge hole (9) comprises a valve configured to control the discharge of water.

15. The exhaust system (50) according to any one of claims 1 to 14, wherein: The sound absorbing material (6) comprises a waterproof coating located on the outside of the sound absorbing material (6).

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