Water-gas separator for fuel cell and fuel cell system

Abstract

The present application relates to the technical field of fuel cells, in particular to a water-gas separator (10) for a fuel cell, comprising: a gas flow channel (1) having an inlet (11) and an outlet (12), the outlet (12) being located above the inlet (11), water-containing gas in the gas flow channel (1) being guided to flow upward; the water collecting cavity (2) is used for collecting water from the water-containing gas, the water collecting cavity (2) is arranged around the gas flow channel (1) in a surrounding manner and is adjacent to the outlet (12), and at least one additional resisting structure (4) designed for increasing the flow resistance of the fluid in the water collecting cavity (2) is arranged in the water collecting cavity (2). According to some embodiments of the invention, the additional resisting structure can be utilized to increase the flow resistance of the fluid in the water collecting cavity, so that the water-gas separation effect of the water-gas separator is improved, more water can be discharged, and the water-gas separation efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, specifically to a water-gas separator for a fuel cell and a fuel cell system. Background Technology

[0002] In fuel cell systems, water is continuously produced as the battery reaction proceeds. If this water gets into the gas passage, it can lead to excessive water content in the fuel cell stack, significantly degrading the system's performance or even causing it to malfunction. To avoid this, a water-gas separator is needed in the fuel cell system to separate the moisture from the gas stream.

[0003] In high-power applications, centrifugal water-gas separators are typically used. A centrifugal water-gas separator is a type of water-gas separator that uses centrifugal force to cause the gas containing moisture to rotate at high speed inside, thereby separating the water from the gas.

[0004] However, the water-gas separation effect and efficiency of existing water-gas separators need to be improved. Utility Model Content

[0005] The purpose of this application is to provide an improved water-gas separator for fuel cells, which has improved water-gas separation effect and efficiency.

[0006] According to a first aspect of this application, a water-gas separator for a fuel cell is provided, the water-gas separator comprising: an airflow passage having an inlet and an outlet, the outlet being located above the inlet, wherein water-containing gas in the airflow passage is guided to flow upward; and a water collection chamber for collecting moisture from the water-containing gas, which is disposed around the airflow passage and adjacent to the outlet, wherein at least one additional baffle structure designed to increase the flow resistance of the fluid within the water collection chamber is provided in the water collection chamber.

[0007] According to an alternative embodiment of this application, the additional blocking structure has a smooth surface.

[0008] According to an alternative embodiment of this application, the additional blocking structure has a streamlined profile.

[0009] According to an optional embodiment of this application, the additional blocking structure is disposed on one of the inner wall of the water collection chamber adjacent to the airflow channel and the outer wall away from the airflow channel, and extends toward the other of the inner wall and the outer wall.

[0010] According to an alternative embodiment of this application, the ratio of the radial distance of the radial extension end of the additional blocking structure relative to one of the radial distances to the radial distance relative to the other is greater than or equal to 1:3.

[0011] According to an alternative embodiment of this application, the additional blocking structure extends upward from the bottom of the water collection chamber.

[0012] According to an optional embodiment of this application, the longitudinal height of the additional blocking structure relative to the bottom of the water collecting chamber is greater than or equal to one-third of the upper limit of the liquid level of the water collecting chamber, and less than or equal to the upper limit of the liquid level of the water collecting chamber.

[0013] According to an optional embodiment of this application, the at least one additional blocking structure includes a plurality of additional blocking structures arranged at equal intervals along the circumferential direction, with a gap formed between two adjacent additional blocking structures, wherein, measured by the angle rotated along the circumferential direction, the ratio of the circumferential dimension of the additional blocking structure to the circumferential dimension of the gap is less than or equal to 1:1 and greater than 0, and / or, the number of the additional blocking structures is in the range of 2 to 10.

[0014] According to an optional embodiment of this application, the additional blocking structure is a block disposed within the water collection cavity; and / or the additional blocking structure is formed at least partially by the inner or outer wall of the water collection cavity protruding toward the interior of the water collection cavity.

[0015] According to an alternative embodiment of this application, the water-air separator includes a first housing portion and a second housing portion defining the airflow passage, the first housing portion and the second housing portion being fitted together to secure the impeller of the water-air separator, wherein the second housing portion provides the inner wall of the water collection chamber forming the additional baffle structure.

[0016] According to a second aspect of this application, a fuel cell is provided, the fuel cell including any of the water-gas separators according to this application.

[0017] According to this application, an additional blocking structure is introduced to increase the flow resistance of the fluid in the water collection chamber, causing the fluid to slow down or even stop, thereby improving the water-gas separation effect of the water-gas separator, promoting more water discharge, and improving the water-gas separation efficiency.

[0018] It is worth noting that the advantages and beneficial effects of this application are not limited to those mentioned above. Those skilled in the art can understand other advantages and beneficial effects not mentioned in this application through the following detailed embodiments and claims. Attached Figure Description

[0019] The principles, features, and advantages of this application will be better understood below with reference to the accompanying drawings. In the drawings:

[0020] Figure 1A cross-sectional view of an existing water-air separator is shown;

[0021] Figure 2 A cross-sectional view of a water-air separator according to a first embodiment of this application is shown;

[0022] Figure 3 A cross-sectional view of a water-air separator according to a second embodiment of this application is shown;

[0023] Figure 4 A cross-sectional view of a water-air separator according to a third embodiment of this application is shown; and

[0024] Figure 5 A top sectional view of a water-air separator according to a fourth embodiment of this application is shown.

[0025] List of reference numerals

[0026] 10' Existing water-air separator

[0027] 10. Water-air separator according to this application

[0028] 1. Airflow channel

[0029] 11 Entrances

[0030] 12 Exports

[0031] 13. Trumpet-shaped part

[0032] 2 Water collection chamber

[0033] 21 Inner wall

[0034] 22 outer wall

[0035] 23 Discharge outlet

[0036] 3 Impeller

[0037] 4. Additional defensive structure

[0038] 5. Housing

[0039] 51 First shell section

[0040] 52 Second shell section

[0041] 6. Spacing

[0042] H represents the upper limit of the liquid level in the water collector chamber.

[0043] h Longitudinal height of the additional retaining structure

[0044] W0 (existing) radial width of the water collection chamber

[0045] w1 The radial distance of the radial extension end of the additional blocking structure relative to the inner wall.

[0046] w2 The radial distance of the radial extension end of the additional blocking structure relative to the outer wall.

[0047] α Circumferential dimensions of the additional supporting structure

[0048] Circumferential dimensions of the β-spacer Detailed Implementation

[0049] To make the technical problems, technical solutions, and beneficial technical effects to be solved by this application clearer, the application will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are only for explaining the principles of this application and are not intended to limit the scope of protection of this application. In the various drawings of this application, features with the same structure or similar function are represented by the same reference numerals. The drawings are not strictly drawn to scale but are exaggerated for clarity.

[0050] Figure 1 A cross-sectional view of an existing water-air separator 10' is shown. Figure 1 As shown, the water-gas separator 10' includes an airflow channel 1. The airflow channel 1 has an inlet 11 and an outlet 12, wherein the outlet 12 is located above the inlet 11, and the water-containing gas in the airflow channel 1 is guided to flow upward. The inlet 11 may open laterally, and the outlet 12 may open longitudinally, such that the water-containing gas flows substantially along the airflow channel 1. Figure 1 The flow direction is indicated by the hollow arrow in the diagram. The water-containing gas may include gases (e.g., hydrogen) and moisture (e.g., produced by a redox reaction). An impeller 3 is arranged within the airflow channel 1, and the impeller 3 is used to achieve water-gas separation using centrifugal force. The water-gas separator 10' also includes a water collection chamber 2 for collecting moisture from the water-containing gas, which is arranged around the airflow channel 1 and adjacent to the outlet 12 (see reference). Figure 5 The water collection chamber 2 and the airflow channel 1 are in fluid communication. The water collection chamber 2 can be arranged downstream of the impeller 3 in the airflow channel 1 (defined relative to the airflow direction). For example, Figure 1 The airflow channel 1 shown may include a funnel-shaped portion 13 located downstream of the impeller 3, and a water collection chamber 2 may be arranged adjacent to and around the funnel-shaped portion 13. The funnel-shaped portion 13 may have a cross-sectional area that gradually increases along the airflow direction, enabling it to guide water-containing gas toward the water collection chamber 2 located around the airflow channel 1.

[0051] When the water-containing gas flows through the impeller 3, the centrifugal force generated by the blade structure and fluid dynamics principles throws the water out of the gas. In particular, under the action of the upward airflow, the water is thrown onto the inner wall of the trumpet-shaped part 13 and further blown into the water collection chamber 2. Specifically, since the water in the water-containing gas is separated in the form of small droplets, it can be completely blown into the water collection chamber 2 under the action of the airflow.

[0052] The water collection chamber 2 includes an outlet 23 and is defined and formed by an inner wall 21 adjacent to the airflow channel 1 and an outer wall 22 away from the airflow channel 1. That is, both the inner wall 21 and the outer wall 22 can be generally circular, thereby forming a generally annular water collection chamber 2 between them. The radial width W0 of the water collection chamber 2 can be defined by the radial distance between the inner wall 21 and the outer wall 22. The inner wall 21 and the outer wall 22 can be separate walls, or they can be provided separately or in combination with another housing part of the water-air separator 10'. The water collection chamber 2 can have a liquid level upper limit H, and if necessary, for example, when the liquid level in the water collection chamber 2 reaches or is close to the liquid level upper limit H, the water in the water collection chamber 2 can be discharged through the outlet 23. The liquid level upper limit H can be the height difference between the bottom of the water collection chamber 2 and the top of the inner wall 21. When the inner wall 21 is integrated with the funnel-shaped portion 13, the liquid level upper limit H can be the height difference between the bottom of the water collection chamber 2 and the top of the funnel-shaped portion 13.

[0053] In practice, it has been found that when the fuel cell system is at its high power point, the flow rate of water-containing gas increases, and the rotational speed of the water-containing gas after passing through impeller 3 accelerates. The high-speed rotating airflow may entrain the separated liquid water along with the gas, meaning that the water in water collection chamber 2 may return to the airflow channel 1 under the influence of the water-containing gas. This reduces the water-gas separation effect and efficiency of the water-gas separator, and also adversely affects the overall performance of the fuel cell system.

[0054] Therefore, the water-gas separator 10 for a fuel cell according to an embodiment of this application is characterized by having at least one additional blocking structure 4 (such as...) provided in the water collection chamber 2, which is designed to increase the flow resistance of the fluid in the water collection chamber 2. Figure 2 (As shown). That is to say, in Figure 1 An additional baffle structure 4 is introduced into the water collection chamber 2 based on the existing water-air separator 10' shown. Figures 2-5Cross-sectional views of a water-gas separator 10 in different embodiments of this application are shown. Advantageously, by introducing and adding the additional blocking structure 4, the resistance to further fluid flow can be increased when the water-containing gas disturbs the fluid in the water collection chamber 2, thereby reducing the fluctuation amplitude of the liquid level in the water collection chamber 2 and reducing the possibility of water splashing out of the water collection chamber 2 or being carried away by the gas. Thus, the water-gas separation effect and efficiency of the water-gas separator can be maximized, thereby improving the overall performance of the fuel cell. Here, the fluid may refer in some cases to water or water containing gas in the water collection chamber 2, and in other cases to water-containing gas, or a combination thereof. That is, the fluid may be water, or a mixture of water and gas.

[0055] It is worth noting that, in this paper, the additional blocking structure 4 is designed and installed additionally for the purpose of increasing the flow resistance of the fluid in the water collection chamber 2, and it should not be understood as part of the water collection chamber 2 according to the prior art (e.g., the existing chamber wall) or a component designed and installed for different other purposes.

[0056] Additionally, advantageously, within the water collection chamber 2, the fluid containing water and gas impacts the auxiliary baffle structure 4 during its flow. This impact aids in water-gas separation; water adheres to or flows off the auxiliary baffle structure 4 due to gravity and inertia after the impact, while the gas continues to flow. Therefore, the auxiliary baffle structure 4 can also function as an auxiliary water-gas separator. After primary water-gas separation via the impeller 3, the gas containing a small amount of water enters the water collection chamber 2 for secondary water-gas separation, further reducing the moisture content in the gas. Afterward, the gas can return to the airflow channel 1 and exit through the outlet 12.

[0057] Preferably, the additional baffle structure 4 has a smooth surface. Alternatively or additionally, the additional baffle structure 4 has a streamlined profile. Advantageously, the smooth surface and / or streamlined profile help the additional baffle structure to increase the flow resistance of the fluid without generating or minimizing the generation of undesirable local turbulence or eddies. For example, when the fluid (e.g., plain water or water containing gas) in the water collection chamber 2 interacts with the additional baffle structure 4, the smooth surface of the additional baffle structure 4 can effectively reduce the coefficient of friction between it and the fluid, allowing the fluid to flow more smoothly as it passes through the additional baffle structure 4, reducing local disturbances caused by surface roughness, and thus avoiding or reducing the generation of undesirable local turbulence. The streamlined profile can guide the flow of the fluid, maintaining a relatively stable flow state as the fluid passes through the additional baffle structure 4, thereby reducing the risk of boundary layer separation and minimizing the formation of eddies.

[0058] Optionally, such as Figure 2As shown, the additional blocking structure 4 can be disposed on one of the inner wall 21 adjacent to the airflow channel 1 and the outer wall 22 away from the airflow channel 1 of the water collection chamber 2, and extend toward the other of the inner wall 21 and the outer wall 22. That is, the additional blocking structure 4 can extend from the inner wall 21 to the outer wall 22, or it can extend from the outer wall 22 to the inner wall 21. Preferably, the ratio of the radial distance w1 of the radially extending end of the additional blocking structure 4 relative to one of the inner wall 21 and the outer wall 22 to its radial distance w2 relative to the other of the inner wall 21 and the outer wall 22 is greater than or equal to 1:3. Figure 2 In the embodiment shown where the additional blocking structure 4 extends from the inner wall 21 to the outer wall 22, the ratio of the radial distance w1 of the radial extension end of the additional blocking structure 4 relative to the inner wall 21 to its radial distance w2 relative to the outer wall 22 is greater than or equal to 1:3. w2 is not zero, that is, the additional blocking structure 4 extends from the inner wall 21 (or the outer wall 22) to the outer wall 22 (or the inner wall 21) and ends thereafter.

[0059] Optionally, the additional blocking structure 4 can be as follows: Figure 2 As shown, it extends upwards from the bottom of the water collection chamber 2. This facilitates the implementation of the additional blocking structure 4. Alternatively, the additional blocking structure 4 can also be as follows: Figure 4 The additional baffle structure 4 is located in the middle portion of the water collection chamber 2, spaced apart from the bottom. It is also conceivable that the additional baffle structure 4 could be arranged at the upper limit of the liquid level in the water collection chamber 2 (e.g., corresponding to the top of the inner wall 21 or the top of the funnel-shaped portion 13). Since the liquid portion near the liquid surface in the water collection chamber 2 is more significantly affected by the disturbance of water-containing gas, and this disturbance gradually weakens with increasing liquid depth, the additional baffle structure 4 can be designed to be, to a certain extent, height-spaced from the bottom of the water collection chamber 2.

[0060] To prevent the additional baffle structure 4 from obstructing the flow of water-containing gas into the space above the water collection chamber 2, the longitudinal height h of the additional baffle structure 4 relative to the bottom of the water collection chamber 2 should be less than or equal to the upper limit H of the liquid level in the water collection chamber 2. Considering that an excessively short additional baffle structure 4 may not provide effective and sufficient flow resistance, the longitudinal height h of the additional baffle structure 4 can be greater than or equal to one-third of the upper limit H of the liquid level in the water collection chamber 2. That is, the ratio of h to H is between 1 / 3 and 1, including the endpoint values. Figure 2 In the illustrated embodiment, the longitudinal height h of the additional blocking structure 4 relative to the bottom of the water collection chamber 2 is also its own extension dimension in that direction. And as in... Figure 4 In the illustrated embodiment (and the embodiment in which the additional blocking structure 4 is arranged at the upper limit position of the liquid level in the water collection chamber 2), the longitudinal height h of the additional blocking structure 4 relative to the bottom of the water collection chamber 2 is the longitudinal distance between the top of the additional blocking structure 4 and the bottom of the water collection chamber 2.

[0061] Alternatively, in some embodiments, such as Figure 5 As shown, at least one additional blocking structure 4 may include a plurality of additional blocking structures 4 arranged at equal intervals along the circumferential direction, with a gap 41 formed between two adjacent additional blocking structures 4. The ratio of the circumferential dimension α of the additional blocking structure 4 to the circumferential dimension β of the gap 41, measured by the angle rotated circumferentially, is less than or equal to 1:1 and greater than 0. Alternatively or additionally, the number of additional blocking structures 4 is in the range of 2 to 10. For example, as... Figure 5 As shown, three additional baffle structures 4 are provided. Advantageously, by one or more of these features, the distribution of the additional baffle structures 4 within the water collection chamber 2 can be optimized, thereby facilitating the gradual or incremental or regional parallel slowing of the fluid flow within the water collection chamber 2, providing sufficient flow resistance while avoiding turbulence or eddies caused by the additional baffle structures 4.

[0062] Alternatively, in some embodiments, such as Figure 2 and Figure 4 As shown, the additional blocking structure 4 can be a block disposed within the water collection chamber 2. Here, the block can have various possible overall shapes or cross-sectional shapes, without much limitation. Correspondingly, the additional blocking structure 4 can be connected to the inner wall 21 or the outer wall 22, in which case the additional blocking structure 4 will occupy part of the space originally occupied by the annular water collection chamber 2. The "connection" can include various suitable connection methods known in the art, such as welding, adhesive bonding, thermal fusion, etc. That is, the water collection chamber 2 and the additional blocking structure 4 are formed separately and connected in separate steps.

[0063] Alternatively or additionally, the additional blocking structure 4 may be formed at least partially by protruding from the inner wall 21 or outer wall 22 forming the water collection chamber 2 toward the interior of the water collection chamber 2. That is, the additional blocking structure 4 is formed integrally by structurally modifying the inner wall 21 or outer wall 22 during the formation process. In this way, the separate connection step mentioned above can be omitted. The inner wall 21 or outer wall 22 may be attached to the housing 5 of the water-air separator 10 or provided directly by the housing 5.

[0064] Exemplarily and preferably, such as Figure 3 As shown, the water-air separator 10 may include a first housing portion 51 and a second housing portion 52 defining an airflow passage 1. The first housing portion 51 and the second housing portion 52 are fitted together to secure the impeller 3 of the water-air separator 10. In particular, the second housing portion 52 may provide an inner wall 21 forming the water collection chamber 2 of the additional baffle structure 4. That is, the inner wall 21 may partially protrude towards the outer wall 22. This allows for simple assembly.

[0065] This application also relates to a fuel cell system, which includes a water-gas separator 10 according to any of the embodiments of this application.

[0066] It should be understood that, for convenience and clarity, the additional blocking structure 4 is shown only schematically as having a rectangular cross-section in each figure, but this application is not limited to this. The cross-section of the additional blocking structure 4 may have other shapes or combinations of shapes, such as arc, semi-circle, convex, etc., and preferably does not have sharp edges.

[0067] Through the embodiments of this application, an additional blocking structure can be used to increase the flow resistance of the fluid in the water collection chamber, causing the fluid to slow down or even stop, thereby improving the water-gas separation effect of the water-gas separator, promoting more water discharge, and improving the water-gas separation efficiency.

[0068] It is worth noting that in this document, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may explicitly or implicitly indicate that at least one of those features is included.

[0069] Furthermore, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," etc., should be interpreted broadly. For example, they can refer to fixed installation / connection, detachable installation / connection, or integral installation / connection; they can refer to direct installation / connection, indirect installation / connection through an intermediate medium, or internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

Claims

1. A water-gas separator for a fuel cell, characterized in that, The water-air separator (10) includes: An airflow channel (1) having an inlet (11) and an outlet (12), the outlet (12) being located above the inlet (11), wherein water-containing gas in the airflow channel (1) is guided to flow upward; and A water collection chamber (2) for collecting moisture from water-containing gas is arranged around the airflow channel (1) and adjacent to the outlet (12). The water collection chamber (2) is provided with at least one additional blocking structure (4) designed to increase the flow resistance of the fluid in the water collection chamber (2).

2. The water-gas separator for a fuel cell according to claim 1, characterized in that, The additional blocking structure (4) has a smooth surface; and / or The additional blocking structure (4) has a streamlined profile.

3. The water-gas separator for a fuel cell according to claim 1 or 2, characterized in that, The additional blocking structure (4) is disposed on one of the inner wall (21) of the water collection chamber (2) adjacent to the airflow channel (1) and the outer wall (22) away from the airflow channel (1), and extends toward the other of the inner wall (21) and the outer wall (22).

4. The water-gas separator for a fuel cell according to claim 3, characterized in that, The ratio of the radial distance (w1) of the radial extension end of the additional blocking structure (4) relative to one of them to its radial distance (w2) relative to the other is greater than or equal to 1:

3.

5. The water-gas separator for a fuel cell according to any one of claims 1, 2, and 4, characterized in that, The additional blocking structure (4) extends upward from the bottom of the water collection chamber (2).

6. The water-gas separator for a fuel cell according to claim 5, characterized in that, The longitudinal height (h) of the additional blocking structure (4) relative to the bottom of the water collection chamber (2) is greater than or equal to one-third of the upper limit of the liquid level (H) of the water collection chamber (2) and less than or equal to the upper limit of the liquid level (H) of the water collection chamber (2).

7. The water-gas separator for a fuel cell according to any one of claims 1, 2, 4, and 6, characterized in that, The at least one additional blocking structure (4) includes a plurality of additional blocking structures (4) arranged at equal intervals along the circumference, with a gap (41) formed between two adjacent additional blocking structures (4). Among them, the ratio of the circumferential dimension (α) of the additional blocking structure (4) to the circumferential dimension (β) of the gap (41) is less than or equal to 1:1 and greater than 0, and / or the number of additional blocking structures (4) is in the range of 2 to 10.

8. A water-gas separator for a fuel cell according to any one of claims 1, 2, 4, and 6, characterized in that, The additional blocking structure (4) is a block installed inside the water collection chamber (2); and / or The additional blocking structure (4) is formed at least in part by the inner wall (21) or outer wall (22) of the water collection cavity (2) protruding toward the interior of the water collection cavity (2).

9. The water-gas separator for a fuel cell according to claim 8, characterized in that, The water-air separator (10) includes a first housing portion (51) and a second housing portion (52) defining the airflow passage (1), the first housing portion (51) and the second housing portion (52) fitting together to fix the impeller (3) of the water-air separator (10). The second housing portion (52) provides the inner wall (21) of the water collection chamber (2) that forms the additional blocking structure (4).

10. A fuel cell system, characterized in that, The fuel cell system includes a water-gas separator (10) according to any one of claims 1-9.

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