A fuel cell system and a water separator thereof

Abstract

The present application provides a fuel cell system and a water separator thereof. The water separator includes a housing having an air inlet and an air outlet, and an anti-backflow device is provided at the air outlet. The anti-backflow device includes a cylindrical channel, a bracket located in the channel, and a disc-shaped diaphragm provided on the bracket. The bracket includes a plurality of arc-shaped support ribs arranged around the axis of the channel, and all the support ribs form a dome shape arched towards the inside of the housing. The diaphragm is arranged perpendicular to the axis of the channel, and the central part of the diaphragm is fixedly connected to the end of the support rib facing the inside of the housing. The water separator provided by the present application can solve the problem of hydrogen backflow on the anode side, and has the advantages of low energy consumption, long service life, and low maintenance cost.

Description

Technical Field

[0001] The present application relates to the technical field of fuel cells, and particularly relates to a fuel cell system and a water separator thereof. Background Art

[0002] A fuel cell is a device that converts the chemical energy of hydrogen into electrical energy. Its advantages are that the product is water, with zero emissions, no pollution, low noise, and high conversion efficiency. It can operate at low temperatures and is the first choice for mobile power sources, base station power sources, and fixed power sources.

[0003] During the operation of a fuel cell engine, a multi-stage ejector is used on the anode side. When the system operates at idle conditions, if there is no anti-backflow structure at the ejector return port, hydrogen will flow back on the anode side of the system, resulting in a low single cell voltage of the fuel cell stack and the system being unable to operate normally. To solve this problem, the traditional approach is to add a normally open solenoid valve at the ejector return port on the anode side of the fuel cell stack. When backflow occurs, the solenoid valve is closed to prevent backflow. However, this anti-backflow mechanism has high costs, large flow resistance, increases the system volume, reduces the volume specific power, and is not conducive to installation. Summary of the Invention

[0004] In view of this, the present application provides a fuel cell system and a water separator thereof. The water separator can solve the problem of hydrogen backflow on the anode side and has the advantages of low energy consumption, long service life, and low maintenance cost.

[0005] To achieve the above object, the present application provides the following technical solutions:

[0006] A water separator of a fuel cell system includes a housing having an air inlet and an air outlet. An anti-backflow device is provided at the air outlet. The anti-backflow device includes a cylindrical channel, a support in the channel, and a disc-shaped diaphragm provided on the support. The support includes a plurality of arc-shaped support ribs arranged around the axis of the channel. All the support ribs form a dome shape arching towards the inside of the housing. The diaphragm is arranged perpendicular to the axis of the channel, and the central part of the diaphragm is fixedly connected to the end of the support rib facing the inside of the housing.

[0007] Optionally, in the above water separator, a support rod is arranged on the axis of the channel. The support rod is fixedly connected to the support rib and passes through the central part of the diaphragm. The support rod is fixedly connected with a limiting plate that abuts against the side of the diaphragm facing away from the support rib.

[0008] Optionally, in the above water separator, the limiting plate is a disc coaxial with the diaphragm.

[0009] Optionally, in the above water separator, the thickness of the limiting plate is 1.3 to 1.5 times the thickness of the diaphragm.

[0010] Optionally, in the above-mentioned water separator, a limiting protrusion is provided on the inner wall of the channel, and the limiting protrusion abuts against the side of the diaphragm facing away from the support rib.

[0011] Optionally, in the above-mentioned water separator, the limiting protrusion is an annular body coaxial with the diaphragm.

[0012] Optionally, in the above-mentioned water separator, the included angle between the tangent direction at the middle position of the support rib and the axis of the channel is 45° to 75°.

[0013] A fuel cell system includes a water separator as disclosed in any one of the above.

[0014] Optionally, in the above-mentioned fuel cell system, the water separator is integrated on the end plate of the fuel cell stack.

[0015] According to the above technical solution, in the water separator provided by the present application, an anti-backflow device is provided at the air outlet. This anti-backflow device includes a cylindrical channel, a bracket located in the channel, and a disc-shaped diaphragm provided on the bracket. The bracket includes a plurality of arc-shaped support ribs arranged around the axis of the channel. All the support ribs form a dome shape arched towards the inside of the housing. Since the diaphragm is arranged perpendicular to the axis of the channel, and the central part of the diaphragm is fixedly connected to the end of the support rib facing the inside of the housing, when the gas in the housing flows outwards, the diaphragm is turned up and stops on the support rib, and the gas can pass through normally, ensuring the normal air outlet function of the air outlet. When the gas at the air outlet flows in the reverse direction, the diaphragm is blown back by the air flow to a state perpendicular to the axis of the channel, closing the channel and playing a role in preventing backflow. Thus, compared with the traditional mechanism using a normally open solenoid valve to prevent backflow, the water separator provided by the present application solves the problem of hydrogen backflow on the anode side, and has the advantages of low energy consumption, long service life, and low maintenance cost. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0017] Figure 1 is an exploded view of the water separator of the fuel cell system provided by the embodiment of the present application;

[0018] Figure 2 is Figure 1 the sectional view of the water separator shown;

[0019] Figure 3 is Figure 1 a schematic diagram of the bracket 5 in

[0020] Figure 4 is Figure 3 a schematic diagram of the diaphragm 4 and the limit plate 54 mounted on the support rod 53 in

[0021] Figure 5 is Figure 4 a top view of the diaphragm 4 in

[0022] In the figure, the markings are as follows:

[0023] 1. Cover plate; 2. Separation filter element; 3. Housing; 4. Diaphragm; 5. Bracket; 51. Flange ring; 52. Support rib; 53. Support rod; 54. Limit plate. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0025] As Figures 1 to 5 shown, the water separator provided in the embodiment of the present application for a fuel cell system includes a housing 3. After removing the cover plate 1 from the housing 3, it is convenient to view the components inside the housing 3 for operations such as maintenance. A separation filter element 2 is provided inside the housing 3, which can separate gas and liquid. The housing 3 is provided with an air inlet and an air outlet. As Figure 2As shown by the dotted line path in the figure, the gas with moisture enters the housing 3 from the air inlet, and flows out from the air outlet after passing through the separation filter element 2. An anti-backflow device is provided at the air outlet. The anti-backflow device includes a cylindrical channel, a bracket 5 located in the channel, and a disc-shaped diaphragm 4 provided on the bracket 5. This channel is communicated with the air outlet of the housing 3. Preferably, this channel is a part of the housing 3. More preferably, the solid part forming this channel and the housing 3 are of an integral structure. The bracket 5 includes a plurality of arc-shaped support ribs 52 arranged around the axis of the channel. All the support ribs 52 form a dome shape arched towards the inside of the housing 3, that is, arched towards the backflow direction of the air outlet. The diaphragm 4 is arranged perpendicular to the axis of the channel, and the central part of the diaphragm 4 is fixedly connected to one end of the support rib 52 facing the inside of the housing 3. The anti-backflow function of the anti-backflow device is realized by the diaphragm 4. After the anti-backflow device is installed on the housing 3, the bracket 5 is fixedly arranged relative to the housing 3. When the gas flows forward, that is, when the gas flows out from the inside of the housing 3, the diaphragm 4 is turned up and stops on the support rib 52, and the gas can pass through normally. When the gas flows backward, the diaphragm 4 is blown back by the air flow to a state perpendicular to the axis of the channel, closing the channel and playing a role in preventing backflow. Compared with the traditional mechanism using a normally open solenoid valve to prevent backflow, the water separator provided in this application solves the problem of hydrogen backflow on the anode side, and has the advantages of low energy consumption, long service life, and low maintenance cost.

[0026] As described above, when the gas flows backward, the diaphragm 4 is blown back by the air flow to a state perpendicular to the axis of the channel. To enable the diaphragm 4 to maintain this state to resist the impact force of the backward flowing gas, various methods can be used to limit the diaphragm 4 in this state. In a preferred embodiment, this application makes the water separator include a support rod 53 arranged on the axis of the channel. The support rod 53 is fixedly connected to the support rib 52 and passes through the central part of the diaphragm 4. The support rod 53 is fixedly connected with a limiting plate 54 that abuts against the side of the diaphragm 4 facing away from the support rib 52. That is to say, the limiting plate 54 is fixed to the support rod 53 and is perpendicular to the axis of the channel. This limiting plate 54 does not deform under the action of the air flow blowing force, and thus can support the diaphragm 4. That is, the backward flowing gas presses the diaphragm 4 against the limiting plate 54. It should be noted that the limiting plate 54 does not close the channel, and the shape of the limiting plate 54 can be various forms such as circular, triangular, or rectangular. In this embodiment, the limiting plate 54 is a disc body coaxial with the diaphragm 4. It is easy to understand that the diameter of the limiting plate 54 is smaller than the diameter d of the diaphragm 4. The thickness A of the limiting plate 54 can be flexibly set according to different material strengths. This application preferably makes the thickness A of the limiting plate 54 be 1.3 times to 1.5 times the thickness δ of the diaphragm 4.

[0027] In another embodiment, the present application can provide that the inner wall of the channel is provided with a limiting projection, and the limiting projection abuts against the side of the diaphragm 4 facing away from the support rib 52. That is to say, different from the aforementioned limiting plate 54 abutting against the middle region of the diaphragm 4 to form a support, the limiting projection is provided on the inner wall of the channel, and the diaphragm 4 is supported by abutting against the region near the edge of the diaphragm 4. Specifically, this limiting projection can be a plurality of bumps distributed along the circumferential direction of the channel, or a flange extending a full circle along the circumferential direction of the channel. Preferably, the present application makes the limiting projection a toroidal body coaxial with the diaphragm 4.

[0028] To make the turned-up diaphragm 4 not easily damaged and at the same time avoid excessive resistance during forward flow, the present application can further optimize the arrangement angle of the support rib 52, so that the included angle between the tangent direction at the middle position of the support rib 52 and the axis of the channel is 45° - 75°, as Figure 3 shown. Complementary to this included angle is the included angle α between the tangent direction at the middle position of the support rib 52 and the plane perpendicular to the support rod 53, that is, the included angle α is preferably 15° - 45°. As Figure 2 and Figure 3 shown, in order to facilitate the installation of the bracket 5 to the air outlet of the housing 3, the present application can make the bracket 5 include a flange ring 51, and the ends of the support ribs 52 away from the diaphragm 4 are all fixedly connected to the flange ring 51. The flange ring 51 is a ring body with a flange structure and has a step surface that can cooperate with the edge of the air outlet. As Figure 3 shown, the distance L in the axial direction of the channel between this step surface and the installation position of the diaphragm 4 is generally set to be half of the outer diameter D of the flange ring 51. As Figure 5 shown, the diameter d of the diaphragm 4 is generally set to be 0.6 times - 0.8 times the outer diameter D of the flange ring 51.

[0029] The present application also provides a fuel cell system, and this fuel cell system includes the water separator disclosed in the above embodiments. Since the water separator disclosed in the above embodiments has the above technical effects, the fuel cell system having this water separator also has the above technical effects, which will not be elaborated herein again. In a preferred embodiment, the present application integrates the water separator on the end plate of the fuel cell stack of the fuel cell system.

[0030] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to the embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A water separator for a fuel cell system, comprising a housing having an air inlet and an air outlet, characterized in that, An anti-backflow device is provided at the air outlet. The anti-backflow device includes a cylindrical channel, a bracket located in the channel, and a disc-shaped diaphragm provided on the bracket. The bracket includes a plurality of arc-shaped support ribs arranged around the axis of the channel, and all the support ribs form a dome shape arched towards the inside of the housing. The diaphragm is arranged perpendicular to the axis of the channel, and the central part of the diaphragm is fixedly connected to the end of the support rib facing the inside of the housing; The bracket includes a flange ring, and the ends of the support ribs away from the diaphragm are all fixedly connected to the flange ring. The flange ring is a ring body with a flange structure and has a step surface capable of cooperating with the edge of the air outlet.

2. The water separator according to claim 1, characterized in that, It includes a support rod arranged on the axis of the channel. The support rod is fixedly connected to the support rib and passes through the central part of the diaphragm. The support rod is fixedly connected with a limit plate that abuts against the side of the diaphragm facing away from the support rib.

3. The water separator according to claim 2, characterized in that, The limit plate is a disc body coaxial with the diaphragm.

4. The water separator according to claim 3, characterized in that, The thickness of the limit plate is 1.3 to 1.5 times the thickness of the diaphragm.

5. The water separator according to claim 1, characterized in that, The inner wall of the channel is provided with a limit protrusion, and the limit protrusion abuts against the side of the diaphragm facing away from the support rib.

6. The water separator according to claim 5, characterized in that, The limit protrusion is a ring body coaxial with the diaphragm.

7. The water separator according to any one of claims 1 to 6, characterized in that, The angle between the tangent direction at the middle position of the support rib and the axis of the channel is 45° to 75°.

8. A fuel cell system, characterized in that, It includes a water separator according to any one of claims 1 to 7.

9. The fuel cell system according to claim 8, characterized in that, The water separator is integrated on the end plate of the fuel cell stack.

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