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CN-122014888-A - Low overpressure breather valve and design method thereof

CN122014888ACN 122014888 ACN122014888 ACN 122014888ACN-122014888-A

Abstract

The invention relates to the technical field of breather valves, in particular to a low-overpressure breather valve which comprises a valve body, a valve seat, a valve disc and a valve cover, wherein the valve seat is arranged in the valve body and is provided with an opening, the valve disc is matched with the opening of the valve seat, the valve cover is connected with the valve disc in a longitudinally movable mode, the shape of the inner wall of the valve cover is matched with the shape of the outer wall of the valve seat, the diameter and the height of the valve cover are set based on the relation among the area of the inner circle of the valve seat, the projection area of the valve cover and the ratio coefficient of air flow pressure difference, so that the overpressure K of the breather valve meets 0< K <8 >, the invention realizes the accurate control of the overpressure of the breather valve through the cooperative matching of the structural size of the valve cover, a theoretical design model and an internal flow resistance network, solves the problems of difficult control and lower setting pressure of VOCs (volatile organic chemicals) due to the excessively wide overpressure interval of the traditional breather valve, enables a storage tank to operate under higher and more stable pressure, and remarkably reduces medium emission loss.

Inventors

  • JIANG PING
  • ZHANG YAN

Assignees

  • 普瑞泰格(南京)安全设备有限公司
  • 南京普瑞泰格安全设备工程有限公司

Dates

Publication Date
20260512
Application Date
20260326

Claims (13)

  1. 1. The low overpressure breather valve is characterized by comprising a valve body (100), a valve seat (200) which is arranged in the valve body (100) and is provided with an opening, a valve disc (300) which is matched with the opening of the valve seat (200), and a valve cover (400) which is connected with the valve disc (300); The valve disc (300) is movably connected with the valve seat (200) along the longitudinal direction, and the shape of the inner wall of the valve cover (400) is matched with the shape of the outer wall of the valve seat (200); the diameter D 1 of the valve housing (400) satisfies the following relation: , , Wherein K is an overpressure value and satisfies 0< K <8%, Is the area of the inner circle of the valve seat (200), Is the projected area of the valve housing (400), For the pressure difference between the lower part of the valve disc (300) and the upper part of the valve cover (400) when the valve disc (300) just reaches the highest opening position And the pressure in the tank at that time Is a ratio of (2).
  2. 2. The low overpressure respiratory valve as set forth in claim 1, wherein said ratio coefficient Calculated by the following formula: , Wherein, the A flow resistance coefficient for the flow of air past the valve disk bypass segment; is the impact stagnation pressure coefficient; is the total flow resistance coefficient of the air flow from the inlet to the outlet.
  3. 3. The low overpressure respiratory valve as set forth in claim 2 wherein said shock stagnation pressure coefficient The calculation formula of (2) is as follows: , Wherein, the The impact efficiency coefficient is 0.7-1.3, As a function of impact efficiency; , , , Wherein, the Is characterized by the depth of impact, satisfies 。
  4. 4. The low overpressure respiratory valve as set forth in any one of claims 1 to 3, wherein a diameter D 1 and an airfoil height h of the valve cover (400) satisfy: ≤h≤ , ≤D 1 ≤ , Wherein, the For the thickness of the valve disc (300), The diameter of the valve disc (300), H is the maximum opening height of the valve disc (300), and D is the inner cavity diameter of the valve body (100).
  5. 5. The design method of the low overpressure breather valve is characterized by comprising the following steps of: according to the stress balance relation and the area of the inner circle of the valve seat (200) Determining the projection area of the target overpressure value K 0 and the valve housing (400) And Is a design constraint relationship of (1); establishing a flow resistance network model of internal flow of the breather valve, and calculating to obtain a ratio coefficient The corresponding relation with the diameter D 1 of the valve cover (400) and the wing section height h; Based on the corresponding relation, obtaining a ratio and a coefficient to be determined in the diameter D 1 and the wing section height h of the valve cover (400) through simulation or experimental optimization fitting, and further determining a value range of D 1 and h which meet K is less than or equal to K 0 ; And manufacturing the valve cover (400) according to the value range of D 1 and h, and performing experimental verification.
  6. 6. The method for designing a low overpressure breather valve as set forth in claim 5, wherein in the flow resistance network model for establishing the internal flow of the breather valve, the flow resistance network model breaks up the internal flow channel of the breather valve into a plurality of flow resistance units connected in series and/or in parallel, including an inlet pipe section, an upstream section of a valve disk, a bypass flow section of the valve disk and an outlet pipe section, and calculates flow resistance coefficients of each section by using a Darcy-Wei Siba Hz formula and a Borda-Carnot formula.
  7. 7. The method for designing a low overpressure respiratory valve as set forth in claim 6, wherein the inlet pipe section has a flow resistance coefficient The calculation formula of (2) is as follows: , Wherein, the Is the darcy friction coefficient; is the length of the inlet pipe section; is the diameter of the inlet pipe section; Is the section area of the inlet pipe section; is the inner diameter and the sectional area of the valve cavity; Is the working fluid density.
  8. 8. The method for designing a low overpressure respiratory valve as set forth in claim 6, wherein a flow resistance coefficient of an upstream section of said valve disc The calculation formula of (2) is as follows: , the distance between the bottom surface of the valve disc and the valve seat when the valve disc reaches the highest opening height; Is the thickness of the valve disc; The height of the valve cover wing section is the height of the valve cover wing section; Is the inner diameter of the valve cavity; Is the inner diameter and the sectional area of the valve cavity.
  9. 9. The method for designing a low overpressure respiratory valve as set forth in any one of claims 6 to 8, wherein the valve disk bypass flow resistance coefficient Comprises the following steps: Dividing the air flow path into a first path far from the outlet side and a second path near the outlet side, and calculating the flow resistance coefficient of the first path And the flow resistance coefficient of the second path ; The total flow resistance is calculated by adopting a parallel flow resistance formula: , Wherein the flow resistance coefficient The calculation formula of (2) is ; Flow resistance coefficient The calculation formula of (2) is ; A resistance to flow around the valve disc path one; A flow resistance coefficient for the flow radially past the valve disc path one; a flow resistance coefficient for the flow past the back pressure side of the valve disc; A flow resistance coefficient for the flow of gas from the back pressure side to the outlet line; the resistance of the air flow around the valve disc path II; is the flow resistance coefficient of the air flow passing through the valve disc path II in the radial direction.
  10. 10. The method of designing a low overpressure respiratory valve as set forth in claim 9, wherein: the said The calculation formula of (2) is as follows: , the said The calculation formula of (2) is as follows: , Wherein, the Is the necking flow loss coefficient; Is the expansion flow loss coefficient; The effective proportionality coefficient of the second flow of the path; Is the annular gap area.
  11. 11. The method of designing a low overpressure respiratory valve as set forth in claim 10, wherein: the said The calculation formula of (2) is as follows: , the said The calculation formula of (2) is as follows: 。
  12. 12. a method of designing a low overpressure respiratory valve as set forth in any one of claims 6, 7, 8 and 10 wherein the outlet pipe section has a flow resistance coefficient The calculation formula of (2) is as follows: , Wherein, the Length of the outlet pipe section; Is the diameter of the outlet pipe section; is the section area of the outlet pipe section.
  13. 13. A method of designing a low overpressure respiratory valve as set forth in any one of claims 5, 6, 7, 8, 10 wherein: In the simulation or experimental optimization, a computational fluid dynamics CFD simulation method is adopted to simulate the internal flow field of the breather valve, and parameterized analysis is carried out by changing the values of D 1 and h to obtain simulation results of a plurality of groups of overpressure values K; In CFD simulation, local grid encryption is carried out on the areas near the valve disc (300) and the valve cover (400), and the grid size is not larger than Wherein t is the edge thickness of the valve cover (400), and steady-state simulation is performed by adopting a k-epsilon turbulence model; In test verification, a plurality of test valve covers (400) with different D 1 and h are manufactured, the opening pressure and the full-opening pressure are tested on a breather valve test bed, the actual overpressure value K is calculated, and the actual overpressure value K is compared with the theoretical value for verification.

Description

Low overpressure breather valve and design method thereof Technical Field The invention relates to the technical field of breather valves, in particular to a low overpressure breather valve and a design method thereof. Background The breather valve of the storage tank is used as core safety environmental protection equipment in storage and transportation systems in industries such as petroleum, chemical industry and the like, and plays an important role in regulating the pressure balance inside and outside the storage tank and preventing equipment damage or safety accidents caused by pressure abnormality. However, the traditional breather valve has long faced a series of outstanding challenges in practical application, namely in the aspect of environmental protection emission, due to wider opening pressure interval in the overpressure emission process, the volatile organic compounds in the storage tank are easy to generate unorganized dissipation in the emission process, and the increasingly severe environmental protection emission requirements are difficult to meet. Despite some technological improvements in the industry, there is a lack of systematic solutions, especially in terms of overpressure control, of precise design theory and methodology, resulting in lower respiratory valve set pressures, wide discharge intervals, and limited VOCs management. Therefore, an environment-friendly breather valve capable of fundamentally reducing the overpressure value, realizing quick opening and closing of the valve and reducing the medium emission is urgently needed, so that the safety and environment-friendly compliance level of a storage tank area are integrally improved. Disclosure of Invention Some simplifications or omissions may be made in this section as well as in the description of the application and in the title of the application, which may not be used to limit the scope of the application. To solve the deficiencies of the prior art, it is an object of the present invention to provide a low overpressure respiratory valve. In order to achieve the aim, the invention adopts the following technical scheme that the low overpressure breather valve comprises a valve body, a valve seat which is arranged in the valve body and is provided with an opening, a valve disc which is matched with the opening of the valve seat, and a valve cover which is connected with the valve disc; The valve disc is movably connected with the valve seat along the longitudinal direction, the shape of the inner wall of the valve cover is matched with the shape of the outer wall of the valve seat, and the diameter D 1 of the valve cover meets the following relation: , , Wherein K is an overpressure value and satisfies 0< K <8%; Is the area of the inner circle of the valve seat; Is the projected area of the valve cover, For the pressure difference between the lower part of the valve disc and the upper part of the valve cover when the valve disc just reaches the highest opening positionAnd the pressure in the tank at that timeIs a ratio of (2). As a preferred embodiment of the low overpressure breather valve according to the invention, the ratio coefficientCalculated by the following formula:, Wherein, the A flow resistance coefficient for the flow of air past the valve disk bypass segment; is the impact stagnation pressure coefficient; is the total flow resistance coefficient of the air flow from the inlet to the outlet. As a preferred embodiment of the low overpressure respiratory valve of the present invention, wherein the shock stagnation pressure coefficientThe calculation formula of (2) is as follows: , Wherein, the The impact efficiency coefficient is 0.7-1.3,As a function of impact efficiency; , , is characterized by the depth of impact, satisfies 。 As a preferable scheme of the low overpressure breather valve, the diameter D 1 and the wing-shaped height h of the valve cover are as follows:≤h≤,≤D1≤ . Wherein, the For the thickness of the valve disc,The diameter of the valve disc is H, the maximum opening height of the valve disc is H, and D is the diameter of the inner cavity of the valve body. According to the invention, through the mutual coordination between the structural size of the valve housing, the theoretical design model and the internal flow resistance network, the accurate control of the overpressure value K of the breather valve (K is less than 8%), the problems of difficult control of the unorganized emission of VOCs and lower setting pressure caused by the excessively wide overpressure interval of the traditional breather valve are solved, the storage tank can operate under higher and more stable pressure, and the medium emission loss is obviously reduced. In order to solve the defects in the prior art, another object of the invention is to provide a design method of a low overpressure breather valve. In order to achieve the above object, the present invention adopts the following technical scheme that the desi