Low-temperature stop valve

Abstract

The invention relates to the technical field of valves, in particular to a low-temperature stop valve. A low-temperature stop valve comprises a valve body, two sides of the valve body are provided with a liquid inlet cavity and a liquid outlet cavity, the valve body is provided with a mounting hole between the liquid inlet cavity and the liquid outlet cavity, and the mounting hole is communicated with the liquid inlet cavity and the liquid outlet cavity, and is characterized in that a valve cover is arranged at the position of the mounting hole, a valve rod is arranged at the position, corresponding to the valve cover, in the valve body, and a valve plate is arranged at the bottom of the valve rod; the valve rod can push the valve plate to move towards the valve deck assembly, a blocking sealing ring is embedded in the valve deck and arranged in the circumferential direction of the valve plate, and the valve plate can completely block the valve deck and abut against the blocking sealing ring. A sealing step with the melting point higher than that of the valve plate is further arranged beside the mounting hole, the sealing step is arranged around the mounting hole, a sealing boss is arranged on the upper side of the valve plate, the sealing boss corresponds to the sealing step in shape, and the sealing boss can abut against the sealing step. The sealing boss can form double sealing, and when the valve plate fails, the LNG can be prevented from further leaking.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and in particular to a cryogenic globe valve. Background Art

[0002] Cryogenic globe valves are applied to storage and transportation equipment for cryogenic liquefied gases such as liquid oxygen, liquid argon, liquid nitrogen, and liquefied natural gas, such as cryogenic pressure vessels like storage tanks, tank trucks, and tank containers, and are used to control the opening or closing of the pipelines of cryogenic pressure vessels.

[0003] When a cryogenic globe valve transports liquefied natural gas, the cryogenic globe valve itself does not generate a fire source, but the leakage caused by seal failure will cause the methane in LNG to mix with air and generate combustion or explosion. Soft seal materials are usually used inside the cryogenic globe valve. When encountering a fire or an indirect fire, the soft seal materials are easily melted due to high temperature. At this time, if the valve is difficult to close, secondary deflagration is likely to occur, further increasing the danger. Summary of the Invention

[0004] To solve the problem that the soft seal material inside the cryogenic globe valve in the prior art is easily melted due to high temperature when encountering a fire or an indirect fire, and at this time, if the valve is difficult to close, secondary deflagration is likely to occur, further increasing the danger, the present application provides a cryogenic globe valve, and the specific solution is as follows.

[0005] A cryogenic globe valve includes a valve body. Liquid inlet cavities and liquid outlet cavities are arranged on both sides of the valve body. An installation hole is arranged in the valve body between the liquid inlet cavity and the liquid outlet cavity, and the installation hole is communicated with the liquid inlet cavity and the liquid outlet cavity. It is characterized in that: a valve cover is arranged at the installation hole, a valve stem is arranged at a position corresponding to the valve cover inside the valve body, a valve plate is arranged at the bottom of the valve stem, the valve stem can push the valve plate to move towards the valve cover assembly, a plugging sealing ring is embedded in the valve cover, the plugging sealing ring is arranged circumferentially around the valve plate, and the valve plate can completely plug the valve cover and abut against the plugging sealing ring; A sealing step with a melting point higher than that of the valve plate is further arranged beside the installation hole, the sealing step is arranged around the installation hole, a sealing boss is arranged on the upper side of the valve plate, the sealing boss is arranged corresponding to the shape of the sealing step, and the sealing boss can abut against the sealing step.

[0006] By adopting the above technical solution, the cryogenic globe valve is provided with a plugging sealing ring on the valve cover, so that the valve plate can completely plug the valve cover and abut against the plugging sealing ring, thereby effectively preventing liquid leakage and improving the sealing performance. At the same time, the sealing step arranged beside the installation hole and the sealing boss on the upper side of the valve plate cooperate with each other. When the valve plate fails due to heat, the sealing step can plug from the outside. Although the plugging effect of the sealing step is slightly worse than that of the valve plate, it can plug LNG when the valve plate fails and avoid further leakage of LNG.

[0007] Optionally, a screw sleeve is provided in the valve body corresponding to the valve stem. Threads are provided on the valve stem, and the valve stem is threadedly connected to the screw sleeve. An adjusting handwheel is further provided on the upper side of the valve stem corresponding to the valve stem. The adjusting handwheel is drivingly connected to the valve stem, and the adjusting handwheel is used to drive the valve stem to move up and down.

[0008] By adopting the above technical solution, the threaded connection between the valve stem and the screw sleeve enables the valve stem to move up and down stably, thereby precisely controlling the opening and closing degree of the valve plate. The driving connection between the adjusting handwheel and the valve stem realizes the function of manual adjustment, facilitating the user to adjust the position of the valve plate according to actual needs and improving the convenience and flexibility of operation.

[0009] Optionally, the valve stem includes an outer cylinder and an inner cylinder. The outer cylinder is sleeved outside the inner cylinder. The outer cylinder is threadedly connected to the screw sleeve, and the outer cylinder is threadedly connected to the inner cylinder. The adjusting handwheel extends into the outer cylinder and is provided with a fitting. A fitting plate is provided on the upper side of the outer cylinder for the magnetic fitting, and a fitting plate is also provided on the lower side of the inner cylinder for the fitting. The fitting can be clamped with the fitting plates on the upper and lower sides. The valve plate is fixedly provided at the bottom of the inner cylinder, and the sealing boss is fixedly provided at the bottom of the outer cylinder.

[0010] By adopting the above technical solution, the inner cylinder and the outer cylinder of the valve stem can be driven independently. When it is necessary to drive the inner cylinder to control the movement of the valve plate, only need to push the adjusting handwheel downward to form a drive between the fitting and the inner cylinder, then the inner cylinder can be driven by the fitting. At this time, the inner cylinder can drive the valve plate to move up and down. By moving the adjusting handwheel up and down, the inner cylinder and the outer cylinder can be respectively controlled to block. When the valve plate fails, it can be protected in time to reduce the deflagration caused by further leakage.

[0011] Optionally, the fitting includes a magnetic clamping block, and the magnetic clamping block can adsorb to the fitting plates on the upper and lower sides.

[0012] By adopting the above technical solution, the magnetic clamping block can adsorb to the fitting plates on the upper and lower sides, thereby realizing a stable connection between the inner and outer cylinders of the valve stem. This design makes the valve stem not easy to loosen during the transmission process, improving the reliability of the structure. At the same time, the magnetic adsorption method is convenient for assembly and disassembly, simplifying the maintenance operation.

[0013] Optionally, a pulling motor is provided on the valve body corresponding to the adjusting handwheel. A pulling rope is provided on the rotating shaft of the pulling motor. The rotating shaft of the pulling motor is arranged on the upper side of the adjusting handwheel. The pulling rope is fixedly connected to the adjusting handwheel and can pull the adjusting handwheel to rotate.

[0014] By adopting the above technical solutions, the setting of the pulling motor can achieve the automatic control of the adjusting handwheel, and the up and down movement adjustment of the valve stem can be completed without manual operation. It can control the adjusting handwheel to adjust faster, and the rotating shaft is located on the upper side of the adjusting handwheel, which can pull the adjusting handwheel upward to control the cooperation between the adjusting handwheel and the outer cylinder, so that when the temperature is high, the pulling can directly pull the sealing boss Optionally, a temperature sensor is further provided on the valve body, and the temperature sensor is electrically connected to the pulling motor. When the temperature sensor detects that the temperature rises to the set value, the pulling motor is started.

[0015] By adopting the above technical solutions, when combustion occurs and the temperature rises, the LNG can be blocked in time, further reducing the leakage situation.

[0016] Optionally, an embedding groove is provided on the sealing step corresponding to the sealing boss, the embedding groove is set according to the shape of the sealing boss, and the sealing boss can extend into and be embedded in the embedding groove.

[0017] By adopting the above technical solutions, by providing an embedding groove corresponding to the shape of the sealing boss on the sealing step, the sealing boss can extend into and be embedded in the embedding groove, thereby increasing the contact area and sealing performance between the sealing boss and the sealing step, and effectively preventing leakage.

[0018] Optionally, a pressing sealing ring is provided in the embedding groove, the pressing sealing ring is arranged around the embedding groove, and the pressing sealing ring is used to abut against the sealing boss.

[0019] By adopting the above technical solutions, the setting of the pressing sealing ring can enhance the sealing performance between the sealing boss and the embedding groove, and effectively prevent fluid leakage. The design of the pressing sealing ring around the embedding groove ensures the uniformity of the seal and further improves the sealing reliability.

[0020] Optionally, a thermal expansion and contraction ring is provided at the position of the sealing boss corresponding to the embedding groove, and the thermal expansion and contraction ring can expand in the embedding groove.

[0021] By adopting the above technical solutions, when the temperature rises, the thermal expansion and contraction ring can expand in the embedding groove, thereby enhancing the sealing performance between the sealing boss and the embedding groove. When the sealing ring fails, the thermal expansion and contraction ring can play a sealing compensation role.

[0022] Optionally, a phase change sheet is provided in the middle of the sealing boss, and the phase change sheet is used to absorb heat.

[0023] By adopting the above technical solutions, the phase change sheet is arranged in the middle of the sealing boss, which can effectively absorb heat and reduce the situation that the valve stem fails due to excessive temperature change.

[0024] In summary, the present application has at least the following beneficial effects: 1. The present application solves the problem that in the prior art, the soft sealing material in the cryogenic stop valve is prone to melting due to high temperature when encountering a fire or an indirect fire. At this time, if the valve is difficult to close, secondary deflagration is likely to occur, further increasing the danger. The present application provides two sealing protections, namely a valve plate and a sealing boss. When a fire or an indirect fire causes the valve plate to fail, the sealing boss can replace the valve plate for plugging, reducing the further leakage of LNG, thereby effectively protecting against the leakage of LNG and reducing the occurrence of further deflagration and other situations.

[0025] 2. The present application also provides a pulling motor and a temperature sensor. When the temperature rises to the set value, the temperature sensor will drive the pulling motor to pull the adjusting handwheel upward as a whole, and at the same time drive the inner cylinder to rotate, which can automatically sense and timely protect against the leakage of LNG, and can effectively reduce further leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of Embodiment 1.

[0027] Figure 2 is a cross-sectional view of Embodiment 1.

[0028] Figure 3 is a cross-sectional view of Embodiment 2.

[0029] Figure 4 is a partial view of Embodiment 2, mainly used to show the chamber of the valve body.

[0030] DESCRIPTION OF THE REFERENCE NUMERALS: 1. Valve body; 11. Liquid inlet chamber; 12. Liquid outlet chamber; 13. Mounting hole; 131. Valve cover; 132. Sealing plugging ring; 14. Sealing step; 141. Embedding groove; 142. Pressing sealing ring; 15. Sleeve; 16. Pulling motor; 161. Pulling rope; 162. Temperature sensor; 2. Valve stem; 21. Valve plate; 22. Sealing boss; 221. Thermal expansion and contraction ring; 23. Adjusting handwheel; 231. Fitting part; 232. Magnetic clamping block; 24. Outer cylinder; 25. Inner cylinder; 26. Fitting plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The following further details the present application through specific embodiments in conjunction with the accompanying drawings.

[0032] Embodiment 1 A cryogenic stop valve, as Figure 1 and Figure 2As shown, it includes a valve body 1, and a liquid inlet cavity 11 and a liquid outlet cavity 12 are arranged on both sides of the valve body 1. A mounting hole 13 is arranged between the liquid inlet cavity 11 and the liquid outlet cavity 12 of the valve body 1, and the mounting hole 13 is connected with the liquid inlet cavity 11 and the liquid outlet cavity 12. A valve cover 131 is arranged at the mounting hole 13, and a valve stem 2 is arranged at a position corresponding to the valve cover 131 in the valve body 1. A valve plate 21 is arranged at the bottom of the valve stem 2, and the valve stem 2 can push the valve plate 21 to move toward the valve cover 131 assembly. A blocking seal ring 132 is embedded on the valve cover 131, and the blocking seal ring 132 is arranged circumferentially around the valve plate 21. The valve plate 21 can completely block the valve cover 131 and abut against the blocking seal ring 132. In specific implementation, the up and down movement of the valve stem 2 can drive the movement of the valve stem 2, and the valve plate 21 can cooperate with the valve cover 131 to completely block the position of the mounting hole 13, thereby achieving blocking.

[0033] like Figure 1 and Figure 2 As shown, a sealing step 14 with a higher melting point than the valve plate 21 is also provided beside the mounting hole 13, and the sealing step 14 is provided around the mounting hole 13. A sealing boss 22 is provided on the upper side of the valve plate 21, and the sealing boss 22 corresponds to the shape of the sealing step 14, and the sealing boss 22 can abut against the sealing step 14. In specific implementation, the sealing boss 22 is provided on the upper side of the valve stem 2. When the valve stem 2 moves, the sealing boss 22 also moves with the valve stem 2, and the valve plate 21 can be moved downward from the valve stem 2 toward the side of the liquid inlet cavity 11. At this time, the sealing boss 22 can cooperate with the sealing step 14 to isolate the liquid inlet cavity 11 from the liquid outlet cavity 12, and the valve can also be closed. The melting point of the sealing boss 22 is higher than that of the valve plate 21, so the sealing boss 22 is blocked by metal or other materials, and the valve plate 21 is made of plastic or other materials. In comparison, the sealing effect of the sealing boss 22 is poor, but as a double protection when the valve plate 21 fails, it can effectively prevent further leakage of LNG.

[0034] like Figure 1 and Figure 2 As shown, a screw sleeve 15 is provided in the valve body 1 corresponding to the valve stem 2, a thread is provided on the valve stem 2, the valve stem 2 is threadedly connected with the screw sleeve 15, and an adjusting hand wheel 23 is provided on the upper side of the valve body 1 corresponding to the valve stem 2, the adjusting hand wheel 23 is transmission-connected with the valve stem 2, and the adjusting hand wheel 23 is used to drive the valve stem 2 to move up and down. In specific implementation, the adjusting hand wheel 23 in this embodiment is provided with a bevel gear, and a matching bevel gear is provided on the valve stem 2, so as to adjust the transmission direction, so that the up and down movement of the valve stem 2 can also be controlled on the side of the valve body 1.

[0035] Working principle: a double seal is provided in the valve body 1. When the valve body 1 fails, the sealing boss 22 can still normally seal the mounting hole 13, thereby further reducing the continuous leakage of LNG caused by temperature.

[0036] Embodiment 2 As Figure 3 and Figure 4 shown, the main difference between the second embodiment and the first embodiment is that the valve stem 2 includes an outer cylinder 24 and an inner cylinder 25. The outer cylinder 24 is sleeved outside the inner cylinder 25. The outer cylinder 24 is threadedly connected to the screw sleeve 15, and the outer cylinder 24 is threadedly connected to the inner cylinder 25. The adjusting handwheel 23 extends into the outer cylinder 24 and is provided with a fitting 231. The outer cylinder 24 is provided with a fitting plate 26 on the upper side of the magnetic fitting 231. The inner cylinder 25 is also provided with a fitting plate 26 on the lower side of the fitting 231. The fitting 231 can be drivingly connected to the fitting plates 26 on the upper and lower sides. The valve plate 21 is fixedly arranged at the bottom of the inner cylinder 25, and the sealing boss 22 is fixedly arranged at the bottom of the outer cylinder 24. The fitting 231 includes a magnetic clamping block 232, and the magnetic clamping block 232 can adsorb to the fitting plates 26 on the upper and lower sides. During specific implementation, the adjusting handwheel 23 is arranged at the upper part of the valve body 1 and can move up and down. When the fitting 231 of the adjusting handwheel 23 is clamped and matched with the outer cylinder 24, the outer cylinder 24 can be driven to move up and down. When the fitting 231 of the adjusting handwheel 23 is clamped and matched with the inner cylinder 25, the inner cylinder 25 can be driven to move up and down.

[0037] As Figure 3 and Figure 4 shown, a pulling motor 16 is arranged on the valve body 1 corresponding to the adjusting handwheel 23. A pulling rope 161 is arranged on the rotating shaft of the pulling motor 16. The rotating shaft of the pulling motor 16 is arranged on the upper side of the adjusting handwheel 23. The pulling rope 161 is fixedly connected to the adjusting handwheel 23 and can pull the adjusting handwheel 23 to rotate. A temperature sensor 162 is also arranged on the valve body 1. The temperature sensor 162 is electrically connected to the pulling motor 16. When the temperature sensor 162 detects that the temperature rises to the set value, the pulling motor 16 is started. During specific implementation, before use, the pulling rope 161 needs to be wound around the adjusting handwheel 23 first. And as the adjusting handwheel 23 rotates to the valve opening state, only then can the pulling rope 161 pull the adjusting handwheel 23 to reset. When the temperature sensor 162 detects a temperature increase, since the rotating shaft of the pulling motor 16 is arranged on the upper side of the adjusting handwheel 23, the pulling motor 16 will pull the adjusting handwheel 23 upward to drive the outer cylinder 24 to rotate. Subsequently, when rotating, the outer cylinder 24 can be driven to rotate. Thus, when the temperature increases, the pulling motor 16 can be started, thereby increasing the temperature.

[0038] As Figure 3 and Figure 4As shown in the figure, an embedding groove 141 is provided on the sealing step 14 corresponding to the sealing boss 22. The embedding groove 141 is arranged according to the shape of the sealing boss 22, and the sealing boss 22 can extend into and be embedded in the embedding groove 141. A pressing sealing ring 142 is arranged in the embedding groove 141. The pressing sealing ring 142 is arranged around the embedding groove 141 and is used to abut against the sealing boss 22. A thermal expansion and contraction ring 221 is arranged at the position of the sealing boss 22 corresponding to the embedding groove 141, and the thermal expansion and contraction ring 221 can expand in the embedding groove 141. A phase change sheet is arranged in the middle of the sealing boss 22, and the phase change sheet is used to absorb heat. In specific implementation, when the temperature rises, the sealing boss 22 is embedded in the embedding groove 141 of the sealing step 14 and expands at the same time, so that the sealing table is fixed in the embedding groove 141, and the sealing performance is improved at the same time.

[0039] Working principle: An inner cylinder 25 and an outer cylinder 24 that can be separately controlled are provided. The inner cylinder 25 and the outer cylinder 24 can be controlled by a single adjusting handwheel 23, so as to realize the separate control of the valve plate 21 and the sealing boss 22. When the valve plate 21 fails, the sealing boss 22 can be used for plugging, so as to reduce the situation of LNG leakage.

[0040] Embodiment III The difference between Embodiment III and Embodiment II is only at the fitting 231. A thermal expansion and contraction block is arranged at the fitting 231. When the thermal expansion and contraction block is heated, it can push the magnetic clamping block 232 to move towards the clamping plate on its upper side. In specific implementation, when a fire occurs, the thermal expansion and contraction block can push the magnetic clamping block 232 to push the clamping part upward to realize the transmission connection in advance, which can reduce the situation that the magnetic clamping block 232 moves too slowly when being pulled and cannot contact the outer cylinder 24, and can further improve the response speed.

[0041] Working principle: The basic working principle is the same as that of Embodiment II, but a thermal expansion and contraction block that can react to temperature in time is added. When a fire occurs, the thermal expansion and contraction block can sense the temperature and expand in time, so that the magnetic clamping block 232 can contact the clamping plate of the outer cylinder 24 faster, pull the outer cylinder 24 to rotate, and can effectively drive the outer cylinder 24 during the rotation process, thereby improving the response speed of leakage protection.

[0042] The above are the preferred embodiments of the present application. The protection scope of the present application is not limited by this. Therefore, all equivalent changes made according to the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A low-temperature cut-off valve, comprising a valve body (1), wherein liquid inlet cavities (11) and liquid outlet cavities (12) are arranged on both sides of the valve body (1), an installation hole (13) is arranged in the valve body (1) between the liquid inlet cavity (11) and the liquid outlet cavity (12), and the installation hole (13) is communicated with the liquid inlet cavity (11) and the liquid outlet cavity (12), and is characterized in that: A valve cover (131) is provided at the installation hole (13). A valve stem (2) is provided inside the valve body (1) at a position corresponding to the valve cover (131). A valve plate (21) is provided at the bottom of the valve stem (2). The valve stem (2) can push the valve plate (21) to move towards the valve cover (131) assembly. A sealing rubber ring (132) is embedded in the valve cover (131). The sealing rubber ring (132) is arranged circumferentially around the valve plate (21). The valve plate (21) can completely seal the valve cover (131) and abut against the sealing rubber ring (132). A sealing step (14) with a melting point higher than that of the valve plate (21) is also provided beside the installation hole (13). The sealing step (14) is arranged around the installation hole (13). A sealing boss (22) is provided on the upper side of the valve plate (21). The sealing boss (22) is arranged corresponding to the shape of the sealing step (14). The sealing boss (22) can abut against the sealing step (14).

2. The cryogenic stop valve according to claim 1, wherein: A screw sleeve (15) is provided inside the valve body (1) corresponding to the valve stem (2). Threads are provided on the valve stem (2). The valve stem (2) is in threaded connection with the screw sleeve (15). An adjusting handwheel (23) is also provided on the upper side of the valve body (1) corresponding to the valve stem (2). The adjusting handwheel (23) is in transmission connection with the valve stem (2). The adjusting handwheel (23) is used to drive the valve stem (2) to move up and down.

3. The cryogenic stop valve according to claim 2, wherein: The valve stem (2) includes an outer cylinder (24) and an inner cylinder (25). The outer cylinder (24) is sleeved outside the inner cylinder (25). The outer cylinder (24) is in threaded connection with the screw sleeve (15). The outer cylinder (24) is in threaded connection with the inner cylinder (25). A fitting (231) is provided inside the outer cylinder (24) where the adjusting handwheel (23) extends. A fitting plate (26) is provided on the upper side of the outer cylinder (24) for the magnetic fitting (231). A fitting plate (26) is also provided on the lower side of the inner cylinder (25) for the fitting (231). The fitting (231) can be in transmission connection with the fitting plates (26) on the upper and lower sides. The valve plate (21) is fixedly arranged at the bottom of the inner cylinder (25). The sealing boss (22) is fixedly arranged at the bottom of the outer cylinder (24).

4. The cryogenic stop valve according to claim 3, wherein: The fitting (231) includes a magnetic clamping block (232). The magnetic clamping block (232) can adsorb to the fitting plates (26) on the upper and lower sides.

5. The cryogenic stop valve according to claim 4, wherein: A pulling motor (16) is provided on the valve body (1) corresponding to the adjusting handwheel (23). A pulling rope (161) is provided on the rotating shaft of the pulling motor (16). The rotating shaft of the pulling motor (16) is arranged on the upper side of the adjusting handwheel (23). The pulling rope (161) is fixedly connected to the adjusting handwheel (23) and can pull the adjusting handwheel (23) to rotate.

6. The cryogenic stop valve according to claim 5, wherein: A temperature sensor (162) is also provided on the valve body (1). The temperature sensor (162) is electrically connected to the pulling motor (16). When the temperature sensor (162) detects that the temperature rises to the set value, the pulling motor (16) is started.

7. The cryogenic stop valve according to claim 6, wherein: An embedding groove (141) is provided on the corresponding sealing step (14) for the sealing boss (22). The embedding groove (141) is arranged according to the shape of the sealing boss (22), and the sealing boss (22) can extend into and be embedded in the embedding groove (141).

8. A low-temperature cut-off valve according to claim 7, characterized in that: A pressing sealing ring (142) is arranged in the embedding groove (141). The pressing sealing ring (142) is arranged around the embedding groove (141), and the pressing sealing ring (142) is used to abut against the sealing boss (22).

9. The cryogenic stop valve according to claim 8, wherein: A thermal expansion and contraction ring (221) is arranged at the position of the sealing boss (22) corresponding to the embedding groove (141). The thermal expansion and contraction ring (221) can expand in the embedding groove (141).

10. A cryogenic stop valve according to claim 9, characterized in that: A phase change sheet is arranged in the middle of the sealing boss (22), and the phase change sheet is used to absorb heat.

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