Fuel cell follow-up gas supply system and gas supply method

Abstract

The present invention discloses a fuel cell follow-up gas supply system and gas supply method, including a follow-up gas supply valve, the follow-up gas supply valve including a valve body and a valve core, a first cavity and a second cavity formed on both sides of the valve core; a third cavity is provided in the first cavity, the valve core has a valve stem, and the valve stem is airtightly matched with the third cavity; an air channel is provided in the valve core, one end of the air channel is connected to the second cavity, and the other end is connected to the third cavity; the bottom of the third cavity has a valve hole, and the end of the valve stem can be closed and matched with the valve hole; a spring is provided between one side of the valve core and the valve body; the valve body has a first gas channel, a second gas channel and a third gas channel respectively connected to the first cavity, the second cavity and the valve hole; a regulating valve is connected to the first gas channel. The present invention has the advantages of ingenious structural design, capable of follow-up adjustment of anode gas and cathode gas to ensure that the pressure difference between the two is maintained within a set range, avoiding damage to the proton exchange membrane, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a fuel cell follow-up gas supply system and a gas supply method. Background Art

[0002] A fuel cell is a power generation device that converts the chemical energy in a fuel directly into electrical energy through a redox reaction involving oxygen or other oxidants. The most common fuel is hydrogen, but other fuels can come from any hydrocarbon that can decompose to produce hydrogen, such as natural gas, alcohols, and methane. These cells offer advantages such as high efficiency, environmental friendliness, and high energy density, making them promising energy and power devices. A fuel cell stack is the core component of a fuel cell system, consisting of multiple fuel cell cells stacked in series. The main components include bipolar plates, membrane electrode assemblies, collector plates, insulator plates, and end plates. The membrane electrode assembly, the core component of a fuel cell, consists of a proton exchange membrane, a catalyst layer, and a gas diffusion layer. The proton exchange membrane prevents gas communication between the anode and cathode, while allowing only protons to pass through, enabling electron transfer. The catalyst layer facilitates the electrochemical reaction between hydrogen and oxygen.

[0003] Existing fuel cells typically use air compressors to increase or decrease the pressure of air and simultaneously increase or decrease the hydrogen supply. To ensure that the pressure difference between air and hydrogen on both sides of the proton exchange membrane is within the allowable range and avoid damage to the proton exchange membrane due to excessive pressure difference, complex algorithms are usually required to match and control the air compressor and proportional valve, which makes it impossible to achieve follow-up adjustment of the two gases. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a gas supply system and gas supply method with an ingenious structural design that can dynamically adjust the anode gas and cathode gas to ensure that the pressure difference between the two is maintained within a set range and avoid damage to the proton exchange membrane.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A fuel cell follow-up air supply system includes a follow-up air supply valve, the follow-up air supply valve includes a valve body and a valve core that can be axially moved and air-tightly fitted in the valve body, and a first cavity and a second cavity are formed on both sides of the valve core. A third cavity with a relatively small cross-sectional area is coaxially arranged in the first cavity, the valve core has a valve stem that extends axially into the third cavity, and the valve stem has a sealing portion that air-tightly fits with the third cavity; an air channel is axially arranged in the valve core, one end of the air channel is connected to the second cavity, and the other end is connected to the third cavity on the side of the sealing portion facing away from the second cavity. The bottom of the third cavity has a valve hole arranged opposite to the valve stem, and the length of the valve stem is greater than the length of the third cavity, so that the end of the valve stem can be closed and fitted on the valve hole; a spring is provided between one side of the valve core and the valve body; the valve body has a first gas channel for connecting a first fluid and a second gas channel and a third gas channel for connecting a second fluid, the first gas channel, the second gas channel and the third gas channel are connected to the first cavity, the second cavity and the valve hole respectively; the first gas channel is connected to a regulating valve for controlling gas pressure or flow.

[0007] Furthermore, the spring is located in the first cavity, the second cavity or the third cavity.

[0008] Furthermore, there is a gap between the valve stem and the side wall of the third cavity, and the valve stem has a vent hole arranged in the radial direction, and the vent hole is connected to the air channel.

[0009] Furthermore, a valve seat is provided at the bottom of the third cavity, and the valve hole is provided on the valve seat.

[0010] Furthermore, the bottom of the first cavity has a cylinder extending toward the valve core, and the third cavity is formed in the cylinder.

[0011] Furthermore, the valve stem has a sealing groove extending along the circumferential direction, and the sealing portion is a first sealing ring provided on the sealing groove.

[0012] Furthermore, the valve core is provided with a second sealing ring that seals with the valve body.

[0013] Furthermore, at least two second sealing rings are provided along the axial direction of the valve core.

[0014] Furthermore, it also includes an anode gas supply assembly and a cathode gas supply assembly connected to the fuel cell through a pipeline, and the second gas channel and the third gas channel are connected in series on the anode gas supply assembly or the pipeline of the anode gas supply assembly; the air inlet end of the regulating valve is connected to the pipeline of the cathode gas supply assembly through a pipeline.

[0015] A gas supply method adopts the fuel cell follow-up gas supply system as described above to supply gas.

[0016] In summary, the present invention has the advantages of clever structural design, the ability to dynamically adjust the anode gas and cathode gas to ensure that the pressure difference between the two is maintained within a set range, and avoid damage to the proton exchange membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the follow-up air supply valve in this embodiment.

[0018] Figure 2 Schematic diagram of the valve core's force. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to the embodiments.

[0020] In specific implementation: A fuel cell follow-up gas supply system includes an anode gas supply assembly and a cathode gas supply assembly connected to the fuel cell through pipelines, and a follow-up gas supply valve, such as Figure 1 As shown, the follow-up air supply valve includes a valve body 1 and a valve core 2 that can be axially moved and air-tightly fitted in the valve body 1, and a first cavity 11 and a second cavity 12 are formed on both sides of the valve core 2. A third cavity 13 with a relatively small cross-sectional area is coaxially arranged in the first cavity 11, and the valve core 2 has a valve stem 21 that extends axially into the third cavity 13, and the valve stem 21 has a sealing portion 22 that air-tightly fits the third cavity 13; an air channel 23 is axially arranged in the valve core 2, and one end of the air channel 23 is communicated with the second cavity 12, and the other end is communicated with the third cavity 13 on the side of the sealing portion 22 facing away from the second cavity 12; the third cavity 13 The bottom of the valve body 1 has a valve hole 14 arranged opposite to the valve stem 21, and the length of the valve stem 21 is greater than the length of the third cavity 13, so that the end of the valve stem 21 can be closed and fitted on the valve hole 14; a spring 3 is provided between one side of the valve core 2 and the valve body 1; the valve body 1 has a first gas channel 15 for connecting a first fluid and a second gas channel 16 and a third gas channel 17 for connecting a second fluid, and the first gas channel 15, the second gas channel 16 and the third gas channel 17 are respectively connected to the first cavity 11, the second cavity 12 and the valve hole 14; the first gas channel 15 is connected to a regulating valve for controlling gas pressure or flow.

[0021] In this embodiment, the valve core 2 has a second sealing ring 25 that seals with the valve body 1. At least two second sealing rings 25 are provided along the axial direction of the valve core 2. The bottom of the first cavity 11 has a cylinder 18 extending toward the valve core 2. The third cavity 13 is formed within the cylinder 18. The bottom of the third cavity 13 is provided with a valve seat 4, and the valve hole 14 is provided on the valve seat 4. The valve stem 21 has a sealing groove extending in the circumferential direction. The sealing portion 22 is a first sealing ring provided in the sealing groove. A gap is provided between the valve stem 21 and the sidewall of the third cavity 13. The valve stem 21 has a radially arranged air vent 24, which is connected to the air passage 23. The spring 3 is located in the first cavity 11 and is coaxially sleeved on the cylinder 18.

[0022] In this embodiment, the second gas channel 16 and the third gas channel 17 are connected in series on the pipeline of the anode gas supply assembly. Specifically, the anode gas supply assembly is connected to the third gas channel 17 via a pipeline, and the second gas channel 16 is connected to the fuel cell via a pipeline. The cathode gas supply assembly is connected to the regulating valve via a pipeline, and the regulating valve is connected to the first gas channel 15 and the fuel cell respectively via a T-junction.

[0023] In this embodiment, high-pressure anode gas enters the third cavity 13 from the second gas channel 16 through the valve hole 14, and then enters the second cavity 12 through the gas channel 23 in the valve core 2. At the same time, cathode gas enters the first cavity from the first gas channel 15.

[0024] At this time, the force on the valve core 2 is as follows: Figure 2 As shown, the gas pressure at the valve hole 14 is P 入 , the corresponding effective area is S 入 ; The gas pressure in the first cavity is P 空 , the corresponding effective area is S 空 , the spring force in the first cavity is F 弹 ; The gas pressure in the second cavity is P 出 , the corresponding effective area is S 出 ;S 出 =S 入 +S 空 The force balance relationship of valve core 2 is as follows:

[0025] P 出 S 出 =P 入 S 入 +P 空 S 空 +F 弹

[0026]

[0027] Usually, in order to reduce P 入 Changes in P 出 The influence of the valve core S 入 Matching the cross-sectional area of ​​the valve hole 14, since the valve hole 14 is a throttle hole, its cross-sectional area is very small, making The ratio is close to 1, The ratio is close to 0, and the above formula can be approximated as:

[0028]

[0029] At this time, the cathode gas pressure (i.e., P 空 ) and the anode gas pressure delivered to the fuel cell (i.e., P 出 ) (i.e. the pressure difference on both sides of the membrane) is:

[0030]

[0031] In the above formula, F 弹 The value of is related to the deformation and elastic coefficient of the spring. The elastic coefficient remains unchanged, while the deformation of the valve core can be almost ignored under the pressure balance state, that is, can be approximated as a constant.

[0032] In this way, no matter the pressure P in the first cavity 11 空 Increase or decrease, the output pressure P of the second cavity 出 The pressure between the two can always be maintained within a set range, thereby achieving follow-up adjustment.

[0033] During the operation of the fuel cell, even if the hydrogen supply pressure fluctuates, as long as the hydrogen input pressure is greater than the required output pressure, the follow-up valve in this embodiment can always maintain the pressure difference on both sides of the membrane within the set value range, thereby avoiding pressure damage to the membrane, which is beneficial to extending the service life, simplifying the control system and saving costs.

[0034] In specific implementation, the user can adjust the effective area S of the valve core 2 according to the system control requirements. 入 、S 空 and S 出 , and the elastic coefficient of the spring are designed, the gas pressure in the second cavity can change with the gas pressure in the first cavity, and the pressure difference between the two can be kept within the set pressure difference range.

[0035] It should be noted that the servo valve of this embodiment can be applied not only to the fuel cell of this embodiment, but also to other fluid servo control scenarios where the pressure difference between two paths needs to be controlled to remain within a set range.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fuel cell follow-up gas supply system, characterized in that: The invention relates to a follow-up air supply valve, wherein the follow-up air supply valve comprises a valve body (1) and a valve core (2) which is axially movable and airtightly fitted in the valve body (1), wherein two sides of the valve core (2) form a first cavity (11) and a second cavity (12) which are separated; a third cavity (13) with a relatively small cross-sectional area is coaxially arranged in the first cavity (11); the valve core (2) has a valve stem (21) which extends axially into the third cavity (13); the valve stem (21) has a sealing portion (22) which is airtightly fitted with the third cavity (13); an air passage (23) is axially arranged in the valve core (2), one end of the air passage (23) is communicated with the second cavity (12), and the other end is communicated with the third cavity (13) on the side of the sealing portion (22) facing away from the second cavity (12); the third cavity The bottom of the body (13) has a valve hole (14) arranged opposite to the valve stem (21), and the length of the valve stem (21) is greater than the length of the third cavity (13), so that the end of the valve stem (21) can be closed and fitted on the valve hole (14); a spring (3) is arranged between one side of the valve core (2) and the valve body (1); the valve body (1) has a first gas channel (15) for connecting a first fluid and a second gas channel (16) and a third gas channel (17) for connecting a second fluid, the first gas channel (15), the second gas channel (16) and the third gas channel (17) being connected to the first cavity (11), the second cavity (12) and the valve hole (14) respectively; the first gas channel (15) is connected to a regulating valve for controlling gas pressure or flow.

2. The fuel cell follow-up gas supply system according to claim 1, characterized in that: The spring (3) is located in the first cavity (11), the second cavity (12) or the third cavity (13).

3. The fuel cell follow-up gas supply system according to claim 1, wherein: There is a gap between the valve stem (21) and the side wall of the third cavity (13), and the valve stem (21) has a vent hole (24) arranged in the radial direction, and the vent hole (24) is connected to the air channel (23).

4. The fuel cell follow-up gas supply system according to claim 1, wherein: A valve seat (4) is provided at the bottom of the third cavity (13), and the valve hole (14) is provided on the valve seat (4).

5. The fuel cell follow-up gas supply system according to claim 1, wherein: The bottom of the first cavity (11) has a cylinder (18) extending toward the valve core (2), and the third cavity (13) is formed in the cylinder (18).

6. The fuel cell follow-up gas supply system according to claim 1, wherein: The valve stem (21) is provided with a sealing groove extending in the circumferential direction, and the sealing portion (22) is a first sealing ring provided on the sealing groove.

7. The fuel cell follow-up gas supply system according to claim 1, wherein: The valve core (2) is provided with a second sealing ring (25) which is in sealing cooperation with the valve body (1).

8. The fuel cell follow-up gas supply system according to claim 7, characterized in that: At least two second sealing rings (25) are provided along the axial direction of the valve core (2).

9. The fuel cell follow-up gas supply system according to any one of claims 1 to 8, characterized in that: The invention also includes an anode gas supply assembly and a cathode gas supply assembly connected to the fuel cell through a pipeline, the second gas channel (16) and the third gas channel (17) are connected in series to the anode gas supply assembly or the pipeline of the anode gas supply assembly; the air inlet end of the regulating valve is connected to the pipeline of the cathode gas supply assembly through a pipeline.

10. A gas supply method, characterized in that: Gas is supplied by using the fuel cell follow-up gas supply system as described in any one of claims 1 to 9.

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