Follow-up valve and pressure follow-up adjusting system

Abstract

The follow-up valve and the pressure follow-up adjusting system comprise the follow-up valve, the follow-up valve comprises a valve body and a valve element, and a first cavity and a second cavity are formed in the two sides of the valve element; a third cavity is formed in the first cavity, a valve rod is arranged on the valve element, and the valve rod is in airtight fit with the third cavity; an air channel is formed in the valve element, one end of the air channel communicates with the second cavity, and the other end of the air channel communicates with the third cavity; a valve hole is formed in the bottom of the third cavity, and the end of the valve rod is matched with the valve hole in a closable mode. A spring is arranged between one side of the valve core and the valve body; the valve body is provided with a first gas channel, a second gas channel and a third gas channel which are communicated with the first cavity, the second cavity and the valve hole respectively. The follow-up valve and the pressure follow-up adjusting system both have the advantages of being ingenious in structural design, capable of conducting follow-up adjustment on two kinds of gas so as to ensure that the pressure difference between the two kinds of gas is kept within a set range, beneficial to reducing control difficulty and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, and particularly to a follow-up valve and a pressure follow-up regulation system. Background Art

[0002] A fuel cell is a power generation device that directly converts the chemical energy in fuel into electrical energy through an oxidation-reduction reaction of oxygen or other oxidants. The most common fuel is hydrogen, and other fuels can come from any hydrocarbon that can decompose into hydrogen, such as natural gas, alcohol, and methane. These cells have the advantages of high efficiency, environmental friendliness, high energy density, etc., and are energy power devices with broad development prospects. A fuel cell stack is the core component of a fuel cell system and is composed of multiple fuel cell monomers stacked in series. The main components include bipolar plates, membrane electrode assemblies, collector plates, insulating plates, and end plates. Among them, the membrane electrode assembly is the core component of the fuel cell and is composed of a proton exchange membrane, a catalytic layer, and a gas diffusion layer. The proton exchange membrane prevents gas communication between the anode and the cathode and only allows protons to pass through to achieve electron transfer. The catalytic layer promotes the electrochemical reaction between hydrogen and oxygen.

[0003] Existing fuel cells usually use an air compressor to pressurize or depressurize air and simultaneously increase or decrease the supply of hydrogen. In order 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, it is usually necessary to use a complex algorithm to match and control the air compressor and the proportional valve, and it is impossible to achieve the follow-up regulation of the two gases. Summary of the Utility Model

[0004] Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the utility model is: how to provide a follow-up valve and a pressure follow-up regulation system with a clever structural design, which can perform follow-up regulation on two fluids to ensure that the pressure difference between the two is maintained within a set range, and is beneficial to reducing the control difficulty.

[0005] To solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A follow-up valve comprises a valve body and a valve core that is axially movable and airtightly fitted within the valve body, wherein two sides of the valve core form a first cavity and a second cavity separated therefrom; a third cavity of relatively smaller cross-sectional area is coaxially arranged within 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 airtightly fits within the third cavity; an air passage is axially arranged within the valve core, one end of the air passage communicates with the second cavity, and the other end communicates with the third cavity on a side of the sealing portion facing away from the second cavity; a valve hole is formed at the bottom of the third cavity, facing the valve stem; the length of the valve stem is greater than that of the third cavity, so that the end of the valve stem can be closure-fitted into 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 being respectively connected to the first cavity, the second cavity, and the valve hole.

[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] A pressure follow-up regulating system comprises the follow-up valve described above.

[0015] Furthermore, the first gas channel is connected to or integrated with a regulating valve for controlling fluid pressure or flow.

[0016] In summary, the servo valve and pressure servo adjustment system of the present invention have the advantages of ingenious structural design, being able to perform servo adjustment on two gases to ensure that the pressure difference between the two is maintained within a set range, and being conducive to reducing the difficulty of control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the follower 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 valve, such as Figure 1 As shown, the follow-up 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, with a first cavity 11 and a second cavity 12 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, 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 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, 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 spool 2 is provided with at least two second sealing rings 25 that are sealingly engaged with the valve body 1. The second sealing rings 25 are arranged axially along the spool 2. The bottom of the first cavity 11 is provided with a cylinder 18 extending towards the spool 2. A third cavity 13 is formed within the cylinder 18. 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. The valve stem 21 is provided with a sealing groove extending circumferentially, and the sealing portion 22 is a first sealing ring provided on the sealing groove. There is a gap between the valve stem 21 and the side wall of the third cavity 13. The valve stem 21 is provided with a vent hole 24 extending radially, and the vent hole 24 is in communication with 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 passage 16 and the third gas passage 17 are connected in series in the pipeline of the anode gas supply assembly. Specifically, the anode gas supply assembly is connected to the third gas passage 17 through a pipeline, and the second gas passage 16 is connected to the fuel cell through a pipeline. The cathode gas supply assembly is connected to the regulating valve through a pipeline, and the regulating valve is respectively connected to the first gas passage 15 and the fuel cell through a tee.

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

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

[0025] P 出 S 出 = P 入 S 入 + P 空 S 空 + F 弹

[0026]

[0027] Generally, in order to reduce the influence of the change of P 入 on P 出 the cross-sectional area of S 入 on the spool matches the cross-sectional area of the valve hole 14. Since the valve hole 14 is a throttle hole and its cross-sectional area is very small, the ratio of is close to 1, and the ratio of is close to 0. The above formula can be approximated as:

[0028]

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

[0030]

[0031] In the above formula, the value of Fs 弹 is related to the deformation amount and elastic coefficient of the spring. The elastic coefficient remains unchanged, and the deformation amount of the spool can be almost ignored in the pressure balance state, that is can be approximated as a constant.

[0032] In this way, whether the pressure P 空 [[ID=P1]]in the first cavity 11 increases or decreases, the output pressure P 出 [[ID=P2]]of the second cavity also increases or decreases accordingly, and the pressure difference between the two can always be maintained within a set range, so as to achieve follow-up adjustment.

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

[0034] Specifically, during implementation, the user can design the effective acting areas S 入 S 空 S 出 on the spool 2 and the elastic coefficient of the spring according to the requirements of system control, so that the gas pressure in the second cavity can change following the change of 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 follow-up valve in this embodiment can be applied not only to the fuel cell in this embodiment, but also to other fluid follow-up control scenarios that require controlling the pressure difference between two paths to remain within a set range.

[0036] The above are only the preferred embodiments of the present invention, and the present invention is not limited thereto. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A follow-up valve, characterized in that, The invention comprises a valve body (1) and a valve core (2) which is axially movable and airtightly fitted in the valve body (1), wherein 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); 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 connected to the third cavity (13) on the side away from the second cavity (12) by the sealing portion (22). The bottom of the third cavity (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, and the first gas channel (15), the second gas channel (16) and the third gas channel (17) are respectively arranged to communicate with the first cavity (11), the second cavity (12) and the valve hole (14).

2. The follow-up valve 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 follow-up valve according to claim 1, characterized in that, 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 follow-up valve according to claim 1, characterized in that, 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 follow-up valve according to claim 1, characterized in that, 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 follow-up valve according to claim 1, characterized in that, 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 follow-up valve according to claim 1, characterized in that, The valve core (2) is provided with a second sealing ring (25) which is in sealing cooperation with the valve body (1).

8. The follow-up valve according to claim 7, wherein, At least two second sealing rings (25) are provided along the axial direction of the valve core (2).

9. A pressure servo regulation system, characterized in that, The utility model comprises a spool valve according to any one of claims 1 to 8.

10. The pressure follow-up adjustment system according to claim 9, characterized in that, The first gas channel (15) is connected to or integrated with a regulating valve for controlling fluid pressure or flow.

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