阅读说明：本技术 减压阀 (Pressure reducing valve ) 是由 蒋宁涛 顾佳敏 徐静云 吴泽宇 冯晓 秦志荣 于 2020-07-03 设计创作，主要内容包括：本申请提供一种减压阀,所述减压阀包括：阀体,其设有气体进入通道、气体排出通道、第一内腔和弹簧室,其中气体进入通道通过第一内腔与气体排出通道流体连通；阀芯,其容纳在第一内腔中,阀芯的外表面被配置成能够沿第一内腔的内表面气密地移动,阀芯包括第一端以及与第一端相反的第二端；弹簧,其容纳在弹簧室中且对阀芯施加弹力；其中,第一内腔中设有阀座,阀座被设置成与阀芯的第一端相对,气体进入通道与第一内腔通过阀座的第一通孔流体连通,其中第一通孔的横截面积小于气体进入通道的横截面积。本申请的减压阀可以避免在工作的初始阶段有过大的力作用在阀芯、弹簧和密封圈等部件上,从而延长减压阀的使用寿命。(The present application provides a pressure reducing valve, the pressure reducing valve includes: a valve body provided with a gas inlet passage, a gas outlet passage, a first inner cavity and a spring chamber, wherein the gas inlet passage is in fluid communication with the gas outlet passage through the first inner cavity; a spool received in the first interior cavity, an outer surface of the spool configured to be hermetically movable along an inner surface of the first interior cavity, the spool including a first end and a second end opposite the first end; a spring accommodated in the spring chamber and applying an elastic force to the spool; wherein a valve seat is arranged in the first inner cavity, the valve seat is arranged opposite to the first end of the valve core, the gas inlet channel is communicated with the first inner cavity through a first through hole of the valve seat in a fluid mode, and the cross-sectional area of the first through hole is smaller than that of the gas inlet channel. The application of the pressure reducing valve can avoid overlarge force acting on the valve core, the spring, the sealing ring and other parts at the initial stage of work, so that the service life of the pressure reducing valve is prolonged.)

1. A pressure relief valve, comprising:

a valve body (10), the valve body (10) being provided with a gas inlet channel (11), a gas outlet channel (12), a first inner cavity (14) and a spring chamber (21), wherein the gas inlet channel (11) is in fluid communication with the gas outlet channel (12) through the first inner cavity (14);

a valve spool (20), the valve spool (20) received in the first interior cavity (14), an outer surface of the valve spool (20) configured to be air-tightly movable along an inner surface of the first interior cavity (14), the valve spool (20) including a first end and a second end opposite the first end;

a spring (30) that is housed in the spring chamber (21) and that applies an elastic force to the spool (20);

characterized in that a valve seat (40) is provided in the first inner chamber (14), the valve seat (40) being arranged opposite to the first end of the valve element (20), the gas inlet channel (11) being in fluid communication with the first inner chamber (14) through a first through hole (41) of the valve seat (40), wherein the cross-sectional area of the first through hole (41) is smaller than the cross-sectional area of the gas inlet channel (21).

2. The pressure reducing valve of claim 1, wherein the spool (20) is configured such that when the spool (20) is moved in the first internal chamber (14) by gas pressure from the gas inlet passage (11), an effective restriction area between the first end of the spool (20) and the valve seat (40) decreases with increasing mass flow rate into the gas inlet passage (11) and increases with decreasing mass flow rate into the gas inlet passage (11).

3. The pressure reducing valve according to claim 2, wherein the valve element (20) is configured such that a first end of the valve element (20) seals the first through hole (41) against the valve seat (40) when the gas pressure of the gas discharge passage (12) reaches a predetermined value.

4. A pressure reducing valve according to claim 2 or 3, characterized in that the pressure to which the valve spool (20) is subjected in its longitudinal direction changes with the gas pressure of the gas inlet passage (11) and the gas outlet passage (12) and tends to be balanced.

5. The pressure reducing valve according to claim 1, wherein the valve seat (40) is a metal or non-metal plate material.

6. The pressure reducing valve according to claim 1, wherein the first end of the spool (20) is provided with an annular protrusion.

7. The pressure reducing valve according to claim 1, characterized in that it comprises a first sealing ring (51) and a second sealing ring (52) arranged on the outer surface of the valve spool (20) in the longitudinal direction of the valve spool (20), and the spring chamber (21) is defined by the first sealing ring (51) and the second sealing ring (52), the spring chamber (21) being provided with a vent hole (13) for communication with the atmosphere of the surroundings.

8. The pressure reducing valve according to claim 7, wherein the spool (20) is provided with an internal passage (24), the first internal cavity (14) and the internal passage (24) being in fluid communication through a second through hole (22) provided on a side wall of the spool (20), the second through hole (22) being provided between a first end of the spool (20) and the first sealing ring (51).

9. The pressure reducing valve of claim 8, wherein the internal passage (24) forms an opening (23) at a second end of the spool (20) opposite the first end.

10. The pressure reducing valve of claim 1, wherein the spring (30) is disposed at a first end of the spool (20), at a second end of the spool (20), or between the first and second ends.

Technical Field

The present invention relates to a pressure reducing valve, and more particularly, to a pressure reducing valve for reducing outlet air pressure in an air supply line having a large pressure difference.

Background

Pressure reducing valves (also called surge valves) are widely used in various gas supply lines, and generally regulate the flow rate of gas by controlling the opening degree of an opening and closing member in a valve body, thereby regulating a high inlet gas pressure to a low outlet gas pressure and stably maintaining the outlet gas pressure within a certain range. In a pipeline with a large pressure difference, for example, a hydrogen supply pipeline of a fuel cell, the pressure in a hydrogen storage tank is as high as 35MPa or more, and the normal working pressure of hydrogen required by a proton exchange membrane of the fuel cell is 0.1 to 0.2MPa, so that a pressure reduction process is required.

Existing pressure reducing valves (e.g., piston type pressure reducing valves) typically utilize contact and separation of surfaces between a valve element and a valve body to effect opening and closing, and a spring to adjust the degree of opening therebetween to effect pressure reduction. In the absence of a pneumatic load, the valve element and valve body are normally held at a maximum opening under the action of a spring. Therefore, in the initial stage of the high-pressure gas entering, because the valve core and the valve body are kept at the maximum opening degree, the instantaneous high pressure of the gas immediately acts on the sealing member, and large stress is applied to the sealing member. If operated over time, the spool movement, air pressure and thermal loading cause wear, fatigue, aging and deformation of the seal ring, resulting in degradation of the sealing function. The high pressure entering instantaneously in the initial stage may cause gas leakage or increase the risk of gas leakage, further affecting the service life of the pressure reducing valve, and may bring about potential safety hazards and the like.

It should be noted that the above-described problems also exist in other fields, such as the fields of petroleum, chemical industry, medicine, food, and the like, in which a pressure reducing valve is used to control the supply of gas, in addition to the field of fuel cells.

Accordingly, there is a need for an improved pressure relief valve that increases the service life of the pressure relief valve.

Disclosure of Invention

The object of the present application is to propose an improved pressure reducing valve to overcome the above mentioned technical problems.

To this end, according to an aspect of the present application, there is provided a pressure reducing valve including: a valve body provided with a gas inlet passage, a gas outlet passage, a first internal cavity and a spring chamber, wherein the gas inlet passage is in fluid communication with the gas outlet passage through the first internal cavity; a spool received in the first interior cavity, an outer surface of the spool configured to be hermetically movable along an inner surface of the first interior cavity, the spool including a first end and a second end opposite the first end; a spring accommodated in the spring chamber and applying an elastic force to the spool; wherein a valve seat is disposed in the first lumen, the valve seat being disposed opposite the first end of the valve element, the gas inlet passage being in fluid communication with the first lumen through a first through-hole of the valve seat, wherein a cross-sectional area of the first through-hole is less than a cross-sectional area of the gas inlet passage.

The application of the pressure reducing valve can avoid the situation that overlarge air pressure acts on the valve core, the spring, the sealing ring and other parts at the initial stage of work, so that the service life of the pressure reducing valve is prolonged.

Drawings

Exemplary embodiments of the present application will now be described in detail with reference to the drawings, with the understanding that the following description of the embodiments is intended to be illustrative, and not limiting of the scope of the application, and in which:

FIG. 1 is a schematic cross-sectional view of a pressure relief valve according to an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of the pressure relief valve shown in FIG. 1 in an operational state;

FIG. 3 is a force analysis schematic of a valve spool of the pressure reducing valve shown in FIG. 2;

fig. 4 and 5 are enlarged schematic views of a portion a of the pressure reducing valve shown in fig. 1 at an initial stage and an operating stage, respectively.

Detailed Description

Preferred embodiments of the present application are described in detail below with reference to examples. In the embodiments of the present application, the present application is described taking a pressure reducing valve for a fuel cell as an example. However, it should be understood by those skilled in the art that these exemplary embodiments are not meant to limit the present application in any way. Furthermore, the features in the embodiments of the present application may be combined with each other without conflict. In the different figures, the same components are denoted by the same reference numerals and other components are omitted for the sake of brevity, but this does not indicate that the pressure reducing valve of the present application may not include other components. It should be understood that the dimensions, proportions and numbers of elements in the drawings are not intended to limit the present application.

The pressure reducing valve of the present application is described below with reference to fig. 1. As shown in fig. 1, the pressure reducing valve of the present application generally includes a valve body 10, a valve spool 20, and a spring 30. The valve body 10 is provided with a gas inlet passage 11, a gas outlet passage 12, a first inner cavity 14 and a spring chamber 21, the gas inlet passage 11 being in fluid communication with the gas outlet passage 12 via the first inner cavity 14. A valve spool 20 is received in the first interior cavity 14, and an outer surface of the valve spool 20 is configured to be air-tightly movable along an inner surface of the first interior cavity 14. The valve spool 20 includes a first end and a second end opposite the first end. In fig. 1, the first end of the spool 20 is shown as the lower end. The spring 30 is accommodated in the spring chamber 21 and applies an elastic force to the spool 20.

As shown in fig. 1, a valve seat 40 is disposed in the first interior chamber 14, the valve seat 40 being disposed opposite the first end of the valve element 20. The gas inlet channel 11 is in fluid communication with the first lumen 14 via a first through hole 41 of the valve seat 40, wherein the first through hole 41 has a cross-sectional area smaller than the cross-sectional area of the gas inlet channel 11. Thus, the high-pressure gas entering from the gas inlet passage 11 is restricted by the first through hole 41 to generate a throttling effect, enters the first inner cavity 14 at a restricted mass flow rate, and pushes the valve element 20 to move in the first inner cavity 14 at a restricted gas pressure. Accordingly, it is possible to reduce the acceleration to which the relevant component to which the force of the spool 20 acts, for example, the spring 30; and the limited gas pressure and acceleration act on e.g. a sealing ring (to be described below) so that it deforms less during movement, reducing the risk of leakage.

In order for the pressure reducing valve to provide a more stable outlet gas pressure at different mass flow rates during normal operating conditions, as shown in fig. 2, the valve spool 20 is configured such that when the valve spool 20 is moved in the first internal chamber 14 by gas pressure from the gas inlet passage 11, the effective flow area S between the first end of the valve spool 20 and the valve seat 40 decreases as the mass flow rate of the inlet gas into the passage 11 (which correlates to the gas pressure within the gas inlet passage 11 and the effective flow area S, as will be described further below) increases, and increases as the mass flow rate of the inlet gas into the passage 11 decreases. In fig. 2, the effective restriction area S is the area of the cylindrical surface defined by the gas restriction region formed between the first end of the spool 20 and the valve seat 40. Since the size of the gas restriction area is determined by the smaller of the effective force-receiving area of the first end of the valve element 20 and the effective force-receiving area of the end surface of the valve seat 40 and the distance between the first end of the valve element 20 and the valve seat 40, and the effective force-receiving area of the first end of the valve element 20 and the effective force-receiving area of the end surface of the valve seat 40 are unchanged, the effective restriction area S can be schematically represented by the distance h between the first end of the valve element 20 and the valve seat 40 (as shown in fig. 2). In fig. 1 and 2, the first end of the spool 20 is shown with a blind hole and a chamfer, and the effective force-receiving area of the first end of the spool 20 is the effective force-receiving area of the chamfered end face (which includes the cross-sectional area of the blind hole), however, the first end of the spool 20 may not include a blind hole, and may also be an end face without a chamfer, or with a radius, or an end face with other various surface features (e.g., protrusions or depressions). Since various formulas for representing and calculating the effective throttle area exist in the prior art, they are not described herein again. Thus, when the mass flow rate through the pressure reducing valve is stabilized, the effective throttle area S decreases as the gas pressure of the gas entering from the gas inlet passage 11 increases, and the effective throttle area S increases as the gas pressure of the gas entering from the gas inlet passage 11 decreases, while the gas pressure of the gas discharge passage becomes larger or smaller, but eventually stabilizes substantially within a defined range.

The relationship between the gas pressure of the gas inlet channel and the effective restriction area can be further explained by the following formula.

Wherein Q represents the mass flow rate, A_throttleRepresenting the effective area, R representing the ideal gas constant, T_inDenotes the temperature of the gas inlet channel, k denotes the adiabatic coefficient, P_inIndicating the gas pressure of the gas entering the channel. From the above equation, it can be seen that when the mass flow rate Q is substantially constant, the gas pressure P as the gas enters the channel_inAt the time of increase, effective throttle area A_throttleDecrease, on the contrary, when the gas pressure P of the gas entering the passage_inWhen reduced, the effective throttle area A_throttleAnd (4) increasing.

In fig. 2, solid arrows indicate paths through which high-pressure gas flows, and open arrows indicate paths through which low-pressure gas flows. How the effective restriction area between the first end of the valve spool 20 and the valve seat 40 varies with the mass flow rate and gas pressure of the gas inlet passage will be described further below in conjunction with fig. 2 and 3.

According to an embodiment of the present application, the pressure reducing valve includes a first sealing ring 51 and a second sealing ring 52 provided on an outer surface of the valve core 20 in a longitudinal direction of the valve core 20 such that a spring chamber 21 for accommodating the spring 30 is defined by the two sealing rings. The spring chamber 21 is provided with a vent hole 13 for communication with the atmosphere of the surrounding environment. As shown in fig. 1 and 2, the vent hole 13 is located between the first seal ring 51 and the second seal ring 52.

The valve spool 20 is provided with an internal passage 24, the first internal cavity 14 and the internal passage 24 are in fluid communication through a second through hole 22 provided on a side wall of the valve spool 20, the second through hole 22 being provided between a first end of the valve spool 20 and the first seal ring 51. Therefore, the high-pressure gas (as indicated by the solid arrows in fig. 2) entering from the gas inlet passage 11 enters the first inner chamber 14 after passing through the first through-hole 41, and enters the inner passage 24 through the second through-hole 22 at a reduced gas pressure (i.e., the gas pressure of the gas discharge passage).

The internal passage 24 forms an opening 23 at a second end of the spool 20 opposite the first end. Accordingly, gas entering the internal passage 24 through the second through-hole 22 (as indicated by the hollow arrow in fig. 2) may flow to the second end of the valve spool 20 to generate gas pressure at the second end. It should be noted that the first through hole 41, the second through hole 22 and the opening 23 may be one or more, and the shape and position thereof may be specifically designed as needed.

As shown in fig. 1 and 2, the spring 30 is disposed in the spring chamber 21 between the first seal ring 51 and the second seal ring 52. Thus, the spring 30 is located in the space formed by the first and second seal rings 51 and 52, which is kept isolated from the incoming gas. In fig. 1 and 2, the spring 30 is disposed between the first and second ends of the valve spool 20 and the spring chamber 21 is shown as being hermetically isolated from the first interior cavity 14, however, the spring 30 may also be disposed at the first end of the valve spool 20, i.e., the lower end shown in fig. 1, or at the second end of the valve spool 20, i.e., the upper end shown in fig. 1. Accordingly, the spring 30 may be configured in a variety of ways, and accordingly, the spring chamber 21 may be in fluid communication with the first interior chamber 14, so long as it is capable of functioning to maintain a balance between the gas pressure of the gas outlet passage and the gas pressure of the gas inlet passage when the mass flow rate and the gas pressure of the gas inlet passage change during operation.

As for the balance relationship between the gas pressure of the gas inlet passage, the gas pressure of the gas outlet passage and the elastic force in the operating state, the following formula can be utilized and explained with reference to fig. 3.

F₁＝F₂+F_spring+F₃+F₄ (1)

F₁＝P_out×A₁ (2)

F₂＝P₀×A₂ (3)

F₃＝P_out×A₃ (4)

F₄＝P_in×A₄ (5)

Wherein, F₁Is the pressure of the gas discharge passage acting on the second end of the valve spool 20, P_outIs the pressure of the gas in the gas discharge channel 12, A₁Is the effective force area of the second end of the spool 20; f₂Is the pressure, P, of the ambient atmosphere acting on the valve element 20₀Is atmospheric pressure, A₂Is the effective force area of the valve element 20 to withstand atmospheric pressure; f₃Is gas dischargeThe pressure of the gas of the channel acting near the first end of the spool 20, A₃Is the effective force area near the first end of the spool 20; f₄Is the pressure, P, of the gas entering the passage acting on the first end of the spool 20_inIs the pressure of the gas in the gas inlet channel 11, A₄Is the effective force area of the first end of the spool 20; f_springIs the spring force of the spring 30 acting on the valve spool 20. In the operating state of the pressure reducing valve, the pressure to which the valve spool 20 is subjected in its longitudinal direction changes with the change in the gas pressure of the gas inlet passage and the gas outlet passage, and tends to be balanced. The above only considers the pressure received in the longitudinal direction of the valve spool 20, and depending on the specific structure of the valve spool 20, there may be more or less force.

From the above formulae (1) to (5), P_out＝(F₂+F_spring+F₃+F₄)/A₁. Accordingly, when the mass flow rate and the gas pressure of the gas entering the passage are changed, the valve spool 20 is moved by changing the elastic force of the spring 30, so that the gas pressure of the gas exiting the passage is maintained substantially within a defined range. For example, when the gas pressure of the gas entering the channel increases, the force F₄Increase, correspondingly P_outIncreasing, and based on the above formula, force F_springAlso increases and the spool 20 moves downward, decreasing the effective orifice area S, and P_outAnd then decreases and goes through a dynamic process to stabilize the pressure of the gas discharge passage. Conversely, when the gas pressure of the gas entering the channel decreases, the force F₄Decrease, correspondingly P_outReduced, and based on the above formula, force F_springAlso decreases and the spool 20 moves upward, increasing the effective throttle area S, and P_outAnd then the gas pressure of the gas discharge passage is increased and stabilized through a dynamic process.

At the initial stage of the operation of the pressure reducing valve, due to the pneumatic load of the gas-free inlet passage, the second end of the spool 20 abuts against the valve body 10 under the action of the spring 30, so that the first end of the spool 20 maintains the maximum distance from the valve seat 40, as shown in fig. 4. When high-pressure gas enters the first through hole 41 of the valve seat 40 through the gas inlet passage 11 and is discharged, the throttled gas enters the first inner chamber 14 and flows into the gas discharge passage 12 at a reduced pressure through a throttle region formed between the first end of the valve element 20 and the valve seat 40, and also flows into the inner passage 24 of the valve element 20. In fig. 4, the gas reducing the gas pressure is indicated by hatched arrows. Then, due to the balance relationship among the various forces described above, the gas pressure of the gas discharge passage causes the valve element 20 to move down gradually to reduce the effective throttle area S while reducing the gas pressure of the gas discharge passage and achieving the pressure balance as described above gradually. As shown in fig. 5, the low pressure gas to reduce the pressure is indicated by hollow arrows. Therefore, in the initial stage, the transient high pressure gas entering the first internal chamber 14 acts on the valve element 20 with a reduced pressure, and the impact on the valve element 20 can be mitigated, thereby reducing the motion acceleration of the valve element 20. In this way the first 51 and second 52 sealing rings are less deformed during movement and are less stressed, reducing the risk of leakage.

In addition, in the operating state of the pressure reducing valve, when the gas pressure of the gas discharge passage 12 increases to reach a predetermined value, the first end of the valve element 20 seals the first through hole 41 against the valve seat 40 according to the above-described pressure balance relationship, so that high-pressure gas cannot continue to enter the first inner chamber 14. To provide a more effective seal, the first end of the valve spool 20 is provided with an annular protrusion, such as the conical protrusion shown in fig. 4-5, which may more effectively abut the valve seat 40 to seal the first through hole 41. Accordingly, the valve seat 40 may be a metal or non-metal plate material, for example, metal materials including carbon steel, alloy steel, copper, aluminum, titanium, etc., and non-metal materials including rubber, plastic, etc.

The working process of the pressure reducing valve is described above with respect to the exemplary structure of the pressure reducing valve shown in fig. 1 to 5, however, the valve core 20 may have a different configuration, and the spring 30 may have a different arrangement, and those skilled in the art may configure and calculate the valve according to the specific pressure reducing valve configuration, and will not be described again.

According to the embodiment of the application, the high-pressure gas enters the inner cavity of the valve body through the through hole with the smaller cross section area, so that the impact on components such as the valve core and the sealing ring can be reduced.

The present application is described in detail above with reference to specific embodiments. It is to be understood that both the foregoing description and the embodiments shown in the drawings are to be considered exemplary and not restrictive of the application. For example, the present application has been described in the preferred embodiment by taking as an example a pressure reducing valve used in the fuel cell field, but the present application can be applied not only in the fuel cell field but also in any field where it is necessary to control the regulation of the gas pressure by using a pressure reducing valve. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit of the application, and these changes and modifications do not depart from the scope of the application.