LNG liquid inlet one-way valve

Abstract

The utility model relates to an LNG (Liquefied Natural Gas) liquid inlet one-way valve, which solves the technical problems in the prior art that the existing liquid inlet one-way valve for a vehicle-mounted LNG pump is complicated in structure, larger in space size, insufficient in shock resistance, short in service life and inconvenient to overhaul and replace parts. The check valve comprises a valve plate, a sealing gasket and a valve seat, the valve seat is clamped at the outer section and the middle section of the through hole of the pump body; the sealing gasket is arranged between the valve seat and the outer section of the pump body; the inner wall of the middle section of the pump body through hole, a step surface between the middle section and the inner section and the upper end surface of the valve seat form a limiting cavity; the valve plate is movably arranged in the limiting cavity; the valve plate is provided with valve plate via holes along the circumference with the circle center as the starting point. The ball valve is small in number of components and simple and compact in structure, and axial end face sealing is achieved between the valve seat and the valve plate.

Description

Technical Field

[0001] This utility model relates to a vehicle-mounted LNG check valve, specifically an LNG inlet check valve. Background Technology

[0002] In recent years, the natural gas vehicle industry has developed rapidly, leading to a continuous increase in demand for on-board LNG pump valve components. Among them, the inlet check valve, as a key component of the LNG cryogenic high-pressure pump, directly affects the pump's operating efficiency. The inlet check valve needs to meet requirements such as large flow rate, low flow resistance, strong impact resistance, and rapid opening and closing.

[0003] Currently, the inlet check valve of the LNG cryogenic high-pressure pump has a complex structure, making maintenance and parts replacement inconvenient. It generally uses conical or spherical seals, which cause wear on the sealing surface when frequently opened and closed, resulting in insufficient impact resistance, short service life, and inability to meet the requirements of long-term vehicle use. Utility Model Content

[0004] The purpose of this utility model is to solve the technical problems of existing LNG inlet check valves for vehicle-mounted pumps, such as complex structure, large size, insufficient impact resistance, short service life, and inconvenience in maintenance and parts replacement, and to provide an LNG inlet check valve.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] An LNG inlet check valve is used to be installed in the pump body through hole of an LNG pump body; the pumping direction is defined as upward, and the pump body through hole includes an outer section, a middle section and an inner section arranged sequentially from bottom to top, and the inner diameter D1 of the outer section, the inner diameter D2 of the middle section and the inner diameter D3 of the inner section decrease sequentially.

[0007] Its special feature is:

[0008] This includes the valve plate, gasket, and valve seat;

[0009] The valve seat is snapped into the outer and middle sections of the pump body through hole, and the sealing gasket is placed between the valve seat and the outer section of the pump body;

[0010] The inner wall of the middle section of the pump body through hole, the stepped surface between the middle section and the inner section, and the upper end face of the valve seat constitute a limiting cavity.

[0011] The valve plate is movably disposed within the limiting cavity, and the outer diameter D21 of the valve plate satisfies the relationship: D2≥D21>D3;

[0012] The valve plate is disc-shaped, and at least four valve plate through holes are opened along the circumference of the diameter D22, with the center of the disc as the starting point. The diameter of the valve plate through holes is D23, which satisfies the relationship D21>D22+D23.

[0013] The upper outer diameter D41 of the valve seat satisfies the relationship: D2≥D41>D22+D23;

[0014] The inner diameter D42 of the valve seat satisfies the relationship: D22-D23>D42.

[0015] Furthermore, the lower end of the valve seat has a convex ring structure, and the outer diameter of the lower end is D43 = D3;

[0016] The outer diameter of the upper end of the valve seat is D41 = D2.

[0017] Furthermore, the sealing gasket is positioned between the stepped surface between the outer and middle sections of the pump body through hole and the upper end face of the convex ring structure of the valve seat, and the valve seat and sealing gasket are pressed together by external parts to achieve a seal.

[0018] Furthermore, the sealing gasket is an annular elastic gasket with a sealing spike structure.

[0019] Furthermore, the inner diameter D3 of the inner section, the diameter D22 of the circumference of the four valve plate through holes, the diameter D23 of the valve plate through holes, and the inner diameter D42 of the valve seat satisfy the following relationship: D3>D22>D22-D23>D42.

[0020] Furthermore, the outer diameter of the valve plate is D21 = D2 - d, and the clearance is d = 1 ± 0.1 mm.

[0021] Furthermore, the diameter of the valve plate through hole, D23, is 60% * (D41 - D42) / 2.

[0022] Furthermore, both the upper and lower edges of the valve plate have rounded corners.

[0023] The lower inner wall of the valve seat has a rounded corner transition.

[0024] Furthermore, there are four through holes in the valve plate, evenly distributed along the circumference of diameter D22.

[0025] Furthermore, the valve plate and valve seat are made of martensitic stainless steel.

[0026] The sealing gasket is made of polychlorotrifluoroethylene.

[0027] The advantages of this utility model compared to the prior art are:

[0028] 1. This utility model provides an LNG inlet check valve with fewer components, a simple and compact structure, and easier installation and maintenance. Compared with existing structures, this utility model has a larger flow rate under the same installation dimensions and eliminates the risk of clogging.

[0029] 2. The LNG inlet check valve provided by this utility model has an axial end face seal between the valve seat and the valve plate. When changes in external temperature cause changes in the size of the parts, the sealing performance is minimally affected.

[0030] 3. The LNG inlet check valve provided by this utility model is designed with axial end face sealing. Due to the small weight of the valve plate and the short opening stroke, it can achieve rapid action without the need for a spring.

[0031] 4. The LNG inlet check valve provided by this utility model is designed with axial end face sealing, so that the wear of the valve plate side is the main part when the check valve is opened and closed, thus achieving a longer service life without affecting the sealing effect. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of an embodiment of an LNG inlet check valve according to this utility model;

[0033] Figure 2 This is a schematic diagram of the valve plate structure in an embodiment of this utility model;

[0034] Figure 3 This is a schematic diagram of the valve seat in an embodiment of this utility model.

[0035] Icon labels:

[0036] 1-LNG pump body; 2-valve plate; 3-sealing gasket; 4-valve seat. Detailed Implementation

[0037] The specific technical solutions in the embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0038] This utility model is designed based on the inlet check valve for vehicle-mounted LNG pumps. It contains only three main components, which are few in number and have a simple and compact structure. Unlike conventional check valves that use conical or spherical seals, this utility model uses an axial end face seal.

[0039] Figure 1 An LNG inlet check valve is provided for this embodiment of the utility model and is installed in the pump body through hole of the LNG pump body 1. The pumping direction of the LNG pump body 1 is defined as upward. The pump body through hole includes an outer section, a middle section and an inner section arranged sequentially from bottom to top, and the inner diameter D1 of the outer section, the inner diameter D2 of the middle section and the inner diameter D3 of the inner section decrease sequentially.

[0040] The LNG inlet check valve includes a valve plate 2, a sealing gasket 3, and a valve seat 4. The sealing gasket 3 is an annular elastic gasket with sealing spikes. The valve plate 2 and valve seat 4 are made of martensitic stainless steel, which has high surface hardness, good compression sealing performance, and is resistant to low temperatures and compatible with LNG. The sealing gasket 3 uses polychlorotrifluoroethylene (PCTFE), a low-temperature resistant and compatible material, instead of a conventional metal gasket. The sealing spikes on it allow for greater deformation of the sealing gasket 3 during compression, reducing the risk of leakage.

[0041] The valve seat 4 is snapped into the outer and middle sections of the pump body through hole. The sealing gasket 3 is set between the stepped surface between the outer and middle sections of the pump body through hole and the upper end face of the convex ring structure of the valve seat 4. The valve seat 4 and the sealing gasket 3 are pressed together by external parts to achieve sealing.

[0042] The inner wall of the middle section of the pump body through hole, the stepped surface between the middle section and the inner section, and the upper end face of the valve seat 4 constitute a limiting cavity; the valve plate 2 is movably set in the limiting cavity, the outer diameter of the valve plate 2 is D21=D2–d>D3, and the gap is d=1±0.1mm.

[0043] refer to Figure 2 Valve plate 2 is disc-shaped with rounded corners at both the upper and lower edges to effectively prevent it from jamming during vertical movement. Four valve plate through holes are evenly distributed along the circumference of diameter D22, starting from the center of valve plate 2. The diameter of each through hole is D23 = 60% * (D41 - D42) / 2, satisfying the relationship D21 >

[0044] D22+D23.

[0045] refer to Figure 3 The lower inner wall of valve seat 4 has a rounded corner transition. The upper outer diameter D41 of valve seat 4 satisfies the relationship: D2≥D41>D22+D23; the inner diameter D42 of valve seat 4 satisfies the relationship: D22-D23>D42. The lower end of valve seat 4 has a convex ring structure, and the lower outer diameter D43=D3; the upper outer diameter D41=D2.

[0046] In this embodiment, the above dimensions need to satisfy the relationship: D3>D22>D22-D23>D42.

[0047] The principle of this embodiment is as follows:

[0048] The valve plate 2 can move freely up and down in the limiting cavity formed by the LNG pump body 1 and the valve seat 4. The three work together to form a unidirectional liquid inlet passage. The structure is simple and the operation is reliable.

[0049] The working process of this embodiment is as follows:

[0050] During the suction stroke of the LNG cryogenic high-pressure pump, the piston in the LNG pump body 1 chamber moves upward to create negative pressure, which drives the valve plate 2 to move upward, and the check valve opens automatically, allowing the pump to draw in liquid.

[0051] During the discharge stroke of the LNG cryogenic high-pressure pump, the piston moves downward, and the valve plate 2 moves downward under its own gravity and the pressure of the high-pressure liquid in the pump body cavity, pressing against the valve seat 4 to form a seal, and the one-way valve closes.

[0052] The above description is merely an embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any equivalent structural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are included within the patent protection scope of this utility model. For those skilled in the art, it will be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model. The scope of this utility model is defined by the appended claims and their equivalents.

Claims

1. An LNG inlet check valve for installation in a pump body through hole of an LNG pump body (1); the pumping direction is defined as upward, and the pump body through hole includes an outer section, a middle section and an inner section arranged sequentially from bottom to top, wherein the inner diameter D1 of the outer section, the inner diameter D2 of the middle section and the inner diameter D3 of the inner section decrease sequentially. Its features are: Includes valve plate (2), sealing gasket (3) and valve seat (4); The valve seat (4) is snapped into the outer and middle sections of the pump body through hole, and the sealing gasket (3) is disposed between the valve seat (4) and the outer section of the pump body (1); The inner wall of the middle section of the pump body through hole, the stepped surface between the middle section and the inner section, and the upper end face of the valve seat (4) constitute a limiting cavity. The valve plate (2) is movably disposed in the limiting cavity, and the outer diameter D21 of the valve plate (2) satisfies the relationship: D2≥D21>D3; The valve plate (2) is disc-shaped, with at least four valve plate through holes opened along the circumference of diameter D22 starting from its center. The diameter of the valve plate through holes is D23, satisfying the relationship D21>D22+D23. The upper outer diameter D41 of the valve seat (4) satisfies the relationship: D2≥D41>D22+D23; The inner diameter D42 of the valve seat (4) satisfies the relationship: D22-D23>D42.

2. The LNG inlet check valve according to claim 1, characterized in that: The lower end of the valve seat (4) is a convex ring structure, and the outer diameter of the lower end is D43 = D3; The upper outer diameter of the valve seat (4) is D41 = D2.

3. The LNG inlet check valve according to claim 2, characterized in that: The sealing gasket (3) is placed between the stepped surface between the outer section and the middle section of the pump body through hole and the upper end face of the convex ring structure of the valve seat (4). The valve seat (4) and the sealing gasket (3) are pressed together by external parts to achieve sealing.

4. An LNG inlet check valve according to claim 3, characterized in that: The sealing gasket (3) is an annular elastic gasket with a sealing spike structure.

5. An LNG inlet check valve according to any one of claims 1-4, characterized in that: The inner diameter D3 of the inner section, the diameter D22 of the circumference of the center of the four valve plate through holes, the diameter D23 of the valve plate through hole and the inner diameter D42 of the valve seat (4) satisfy the following relationship: D3>D22>D22-D23>D42.

6. An LNG inlet check valve according to claim 5, characterized in that: The outer diameter of the valve plate (2) is D21 = D2 - d, and the gap is d = 1 ± 0.1 mm.

7. An LNG inlet check valve according to claim 6, characterized in that: The diameter of the valve plate through hole is D23 = 60% * (D41 - D42) / 2.

8. An LNG inlet check valve according to claim 7, characterized in that: The upper and lower edges of the valve plate (2) are both rounded. The lower inner wall of the valve seat (4) has a rounded corner transition.

9. An LNG inlet check valve according to claim 8, characterized in that: The valve plate has four through holes, which are evenly distributed along the circumference of the diameter D22.

10. An LNG inlet check valve according to claim 1, characterized in that: The valve plate (2) and valve seat (4) are made of martensitic stainless steel. The sealing gasket (3) is made of polychlorotrifluoroethylene.

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