Ultralow-temperature regulating valve and using method thereof

Abstract

The invention discloses an ultralow-temperature regulating valve, which belongs to the technical field of control valves and comprises a valve body, a valve cover is fixedly mounted at the top of the valve body, a sealing sleeve is fixedly mounted at the top of the valve cover, a gland is fixedly mounted at the top of the sealing sleeve, a valve rod penetrates through the gland, and the bottom of the valve rod penetrates through the sealing sleeve and the valve body. A valve element is fixedly installed at the end, located in the valve body, of the valve rod and movably abuts against the valve body. The valve core is matched with the valve seat in the valve body to control a medium to flow into the valve body, and the sealing sleeve is arranged to seal the whole valve, so that the medium is prevented from leaking during use, and the practicability of the regulating valve is favorably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of control valves, and in particular to an ultra-low temperature regulating valve and a use method thereof. Background Art

[0002] With the rapid development of the domestic economy, the demand and output of cryogenic products are increasing day by day, and liquid oxygen, liquid nitrogen, liquid helium and liquefied natural gas are widely used. The temperature of liquid helium is -254℃, the temperature of liquid nitrogen is -196℃, the temperature of liquid oxygen is -183℃, and the temperature of liquefied natural gas is -162℃. The fractionation, storage and transportation of these products require a large number of ultra-low temperature regulating valves. The use of ultra-low temperature regulating valves is gradually increasing, and users' requirements for the technical performance of ultra-low temperature regulating valves are also gradually increasing.

[0003] When the existing ultra-low temperature regulating valve is in use, a packing seal is used. The internal space of the valve cavity is small, and the medium temperature is transmitted from the valve stem to the sealing packing, which affects the movement of the valve stem and reduces the control accuracy of the regulating valve. The freezing of the packing will also affect the sealing performance of the regulating valve and cause leakage of the medium. Therefore, an ultra-low temperature regulating valve and a method for using the same are proposed. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides an ultra-low temperature regulating valve to solve the above problems.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: an ultra-low temperature regulating valve, comprising a valve body, a valve cover fixedly installed on the top of the valve body, a sealing sleeve fixedly installed on the top of the valve cover, a pressure cover fixedly installed on the top of the sealing sleeve, a valve stem passed through the pressure cover, the bottom of the valve stem passed through the sealing sleeve and the valve body, a valve core fixedly installed at one end of the valve stem located in the valve body, and the valve core movably abuts against the valve body.

[0006] Preferably, the valve body is provided with a valve cavity, a first condensation cavity, and a second condensation cavity in sequence from bottom to top, and the valve cavity, the first condensation cavity, and the second condensation cavity are connected to each other;

[0007] The bottom of the valve cavity is provided with a feed inlet through the bottom of the valve body, one side of the valve cavity is provided with a discharge port through the side wall of the valve body, a sealing valve seat is provided at the bottom of the valve cavity, the sealing valve seat is communicated with the feed inlet, and a first upper valve seat is provided at the top of the valve cavity;

[0008] A first connecting hole is provided at the bottom of the first condensing chamber, the first connecting hole is communicated with the first upper valve seat, a first condensing plate is fixedly installed on the inner wall of the first condensing chamber, and a second upper valve seat is provided at the top of the first condensing chamber;

[0009] A second connecting hole is opened at the bottom of the second condensing chamber, the second connecting hole is communicated with the second upper valve seat, a second condensing plate is fixedly installed on the inner wall of the second condensing chamber, and the bottom of the valve cover is movably connected with the top of the second condensing chamber.

[0010] Preferably, the valve core includes a sealing valve core, a first upper valve core, and a second upper valve core. The sealing valve core is fixedly installed on the bottom of the valve stem, the first upper valve core and the second upper valve core are both fixedly installed on the valve stem, the first upper valve core is located above the sealing valve core, the second upper valve core is located above the first upper valve core, the sealing valve core is movably abutted against the sealing valve seat, the first upper valve core is movably abutted against the first upper valve seat, and the second upper valve core is movably abutted against the second upper valve seat.

[0011] Preferably, the connection between the valve core and the valve body is nickel-plated.

[0012] Preferably, a packing is provided in the sealing sleeve, the packing abuts between the sealing sleeve and the valve stem, the valve stem is slidably connected to the packing, the bottom of the gland is movably clamped on the top of the sealing sleeve, and the bottom of the gland is movably abutted against the packing.

[0013] Preferably, the valve stem comprises a first valve stem and a second valve stem, the first valve stem and the second valve stem are welded and fixed to each other, the first valve stem is located in the sealing sleeve, and the second valve stem is located in the valve body.

[0014] Preferably, the second valve stem and the valve core are both hollow structures, and their cavities are interconnected, and the cavity is filled with heat insulation material.

[0015] Preferably, a mounting groove is provided on the top of the valve cover, the bottom of the sealing sleeve is inserted into the mounting groove, and the valve cover and the sealing sleeve are fixed by welding.

[0016] Preferably, the sealing sleeve is longer than 50 cm.

[0017] The present invention also provides an ultra-low temperature regulating valve and a method for using the same, which uses the ultra-low temperature regulating valve described above, further comprising a pneumatic actuator and a valve positioner, wherein the pneumatic actuator is fixedly connected to the top of the valve stem, and further comprising the following steps:

[0018] S1. First, assemble the regulating valve, evacuate the valve cavity, the first condensation cavity, and the second condensation cavity, connect the feed pipe of the feed port medium, connect the discharge port with the discharge pipe of the medium, and install the pneumatic actuator and the valve positioner on the top of the regulating valve;

[0019] S2, input control signal, start the pneumatic actuator, the pneumatic actuator drives the valve stem to move upward, the sealing valve core is separated from the sealing valve seat, the first upper valve core is in contact with the first upper valve seat, the second upper valve core is in contact with the second upper valve seat, and the medium flows out from the feed port through the valve cavity and out of the discharge port.

[0020] S3, start the first condensation plate and the second condensation plate to condense the medium gas in the first condensation chamber and the second condensation chamber to form a liquid medium, which is concentrated at the inner bottom of the first condensation chamber and the second condensation chamber to contact the first upper valve core and the second upper valve core.

[0021] S4. After the medium flowing out of the discharge port is sufficient, the control signal is input again to start the actuator to reset, drive the valve stem to move downward and reset, the sealing valve core abuts against the sealing valve seat, blocking the flow of the medium, the first upper valve core is separated from the first upper valve seat, and the second upper valve core is separated from the second upper valve seat, the liquid medium in the second condensation chamber flows into the first condensation chamber from the second connecting hole, and the liquid medium in the first condensation chamber flows into the valve chamber from the first connecting hole and remains at the bottom of the valve chamber.

[0022] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0023] 1. The valve core cooperates with the valve seat in the valve body to control the medium to flow into the valve body. The sealing sleeve is used to seal the valve as a whole to prevent leakage of the medium during use, which is beneficial to improve the practicality of the regulating valve.

[0024] 2. By setting the internal structure of the valve body, a valve cavity and two condensation cavities are set, and three valve cores are set on the valve stem to seal the inner chambers of the valve body and open them respectively. The medium that penetrates into the condensation cavity is condensed by the condensation plate and flows into the valve cavity again. It is discharged out of the valve body when the regulating valve is opened next time. The medium has a large penetration backflow space, which can prevent medium leakage and is beneficial to improving the practicality of the regulating valve.

[0025] 3. By setting a longer sealing sleeve, the length of the packing is guaranteed. When the medium leaks, the packing is frozen and it takes a long time to become completely ineffective, which saves time for later maintenance and further improves the practicality of the regulating valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the overall structure of an ultra-low temperature regulating valve in the embodiment;

[0027] Figure 2 It is a cross-sectional view of the overall structure of an ultra-low temperature regulating valve in the embodiment;

[0028] Figure 3 A super low temperature regulating valve in the embodiment Figure 2 The structural schematic diagram of A is shown;

[0029] Figure 4 A super low temperature regulating valve in the embodiment Figure 2 The schematic diagram of the structure at B is shown;

[0030] Figure 5 This is a schematic diagram of the matching structure of a valve stem and a valve core of an ultra-low temperature regulating valve in an embodiment;

[0031] Wherein: 1. valve body; 11. valve cavity; 111. feed port; 112. discharge port; 113. sealing valve seat; 114. first upper valve seat; 12. first condensation cavity; 121. first connecting hole; 122. first condensation plate; 123. second upper valve seat; 13. second condensation cavity; 131. second connecting hole; 132. second condensation plate; 2. valve cover; 21. mounting groove; 3. valve stem; 31. first valve stem; 32. second valve stem; 4. valve core; 41. sealing valve core; 42. first upper valve core; 43. second upper valve core; 5. sealing sleeve; 51. packing; 6. pressure cover. DETAILED DESCRIPTION

[0032] The following is attached to the instruction manual Figure 1-5 , the technical solution of the present invention is explained through specific embodiments.

[0033] Embodiment:

[0034] like Figure 1 and Figure 2 As shown, an ultra-low temperature regulating valve provided by the present invention includes a valve body 1, a valve cover 2 is fixedly installed on the top of the valve body 1 by bolts, a sealing sleeve 5 is welded and fixed on the top of the valve cover 2, a pressure cover 6 is fixedly installed on the top of the sealing sleeve 5 by bolts, a valve stem 3 is passed through the pressure cover 6, the bottom of the valve stem 3 is passed through the valve body 1 and the sealing sleeve 5, a valve core 4 is fixedly installed at one end of the valve stem 3 located in the valve body 1, and the valve core 4 is movably abutted against the valve body 1.

[0035] like Figure 2 and Figure 3 As shown, the valve body 1 is provided with a valve chamber 11, a first condensation chamber 12, and a second condensation chamber 13 from bottom to top, and the valve chamber 11, the first condensation chamber 12, and the second condensation chamber 13 are connected to each other;

[0036] The bottom of the valve cavity 11 penetrates through the bottom of the valve body 1 to form a feed inlet 111, and one side of the valve cavity 11 penetrates through the side wall of the valve body 1 to form a discharge port 112. A sealing valve seat 113 is provided at the bottom of the valve cavity 11, and the sealing valve seat 113 is communicated with the feed inlet 111. A first upper valve seat 114 is provided at the top of the valve cavity 11.

[0037] A first connecting hole 121 is provided at the bottom of the first condensing chamber 12, and the first connecting hole 121 is connected to the first upper valve seat 114. A first condensing plate 122 is fixedly installed on the inner wall of the first condensing chamber 12, and a second upper valve seat 123 is provided at the top of the first condensing chamber 12.

[0038] A second connecting hole 131 is provided at the bottom of the second condensing chamber 13 , which is connected to the second upper valve seat 123 . A second condensing plate 132 is fixedly mounted on the inner wall of the second condensing chamber 13 . The bottom of the valve cover 2 is movably connected to the top of the second condensing chamber 13 .

[0039] The valve core 4 includes a sealing valve core 41, a first upper valve core 42, and a second upper valve core 43. The sealing valve core 41 is fixedly installed at the bottom of the valve stem 3, and the first upper valve core 42 and the second upper valve core 43 are both fixedly installed on the valve stem 3. The first upper valve core 42 is located above the sealing valve core 41, and the second upper valve core 43 is located above the first upper valve core 42.

[0040] The sealing valve core 41 movably contacts the sealing valve seat 113 , the first upper valve core 42 movably contacts the first upper valve seat 114 , and the second upper valve core 43 movably contacts the second upper valve seat 123 .

[0041] It should be noted that, in this embodiment, the connections between the valve core 4 and the valve body 1 are nickel-plated, that is, the connection between the sealing valve core 41 and the sealing valve seat 113 is nickel-plated, the connection between the first upper valve core 42 and the first upper valve seat 114 is nickel-plated, and the connection between the second upper valve core 43 and the second upper valve seat 123 is nickel-plated. The length of the sealing sleeve 5 is greater than 50 cm.

[0042] like Figure 4 As shown, a mounting groove 21 is provided on the top of the valve cover 2, the bottom of the sealing sleeve 5 is inserted into the mounting groove 21, the valve cover 2 and the sealing sleeve 5 are welded and fixed, a packing 51 is provided in the sealing sleeve 5, the packing 51 abuts between the sealing sleeve 5 and the valve stem 3, the valve stem 3 and the packing 51 are slidably connected, and the valve cover 2 is welded and fixed to the sealing sleeve 5, and the sealing sleeve 5 ... Figure 2 and Figure 4 ,from Figure 2 It can be seen from the figure that the bottom of the gland 6 is movably clamped to the top of the sealing sleeve 5, and the bottom of the gland 6 is movably abutted against the packing 51.

[0043] like Figure 5 As shown, the valve stem 3 includes a first valve stem 31 and a second valve stem 32. The first valve stem 31 and the second valve stem 32 are welded and fixed to each other. The first valve stem 31 is located in the sealing sleeve 5, and the second valve stem 32 is located in the valve body 1. The second valve stem 32 and the valve core 4 are both hollow structures, and their cavities are interconnected. The cavity is filled with insulation material, and the insulation material is the prior art.

[0044] Furthermore, it also includes a pneumatic actuator and a valve positioner which are not shown in the figure. The pneumatic actuator and the valve positioner are both existing technologies and can be installed on other components above the regulating valve, or directly connected to the regulating valve. The pneumatic actuator can use a driving component such as a cylinder to connect with the top of the valve stem 3, thereby driving the valve stem 3 to move up and down. The working stroke, flow characteristics and optimal working state of the regulating valve depend on specific needs. The actuator is started to change the stroke of the valve stem 3 according to the control signal, thereby driving the axial movement of the valve core 4, and then revising the matching clearance between the valve core 4 and the valve body 1, so as to achieve the purpose of controlling the flow, opening and closing, pressure and other parameters of the regulating valve.

[0045] Note: When the regulating valve is closed, Figure 2 As shown, the sealing valve core 41 is completely in contact with the sealing valve seat 113, the feed port 111 is blocked, the medium cannot enter the valve cavity 11, the first upper valve core 42 is separated from the first upper valve seat 114 and the second upper valve core 43 is separated from the second upper valve seat 123, and there is a small gap;

[0046] When a small gap is opened between the sealing valve core 41 and the sealing valve seat 113, the first upper valve core 42 and the second upper valve core 43 contact the first upper valve seat 114 and the second upper valve seat 123 respectively, thereby blocking the communication between the valve cavity 11, the first condensation cavity 12 and the second condensation cavity 13;

[0047] When the sealing valve core 41 is completely separated from the sealing valve seat 113 , the first upper valve core 42 and the second upper valve core 43 are completely in contact with the first upper valve seat 114 and the second upper valve seat 123 , respectively.

[0048] Directions:

[0049] S1. First, assemble the regulating valve, evacuate the inside of the valve chamber 11, the first condensation chamber 12, and the second condensation chamber 13, connect the feed pipe of the feed port 111 to the medium, connect the discharge port 112 to the discharge pipe of the medium, and install the pneumatic actuator and the valve positioner on the top of the regulating valve;

[0050] S2, input control signal to start the pneumatic actuator, the pneumatic actuator drives the valve stem 3 to move upward, the sealing valve core 41 is separated from the sealing valve seat 113, the first upper valve core 42 is in contact with the first upper valve seat 114, the second upper valve core 43 is in contact with the second upper valve seat 123, and the medium flows out from the feed port 111 through the inside of the valve cavity 11 and out of the discharge port 112.

[0051] S3. Start the first condensation plate 122 and the second condensation plate 132 to condense the medium gas in the first condensation chamber 12 and the second condensation chamber 13 to form a liquid medium, which is concentrated at the inner bottom of the first condensation chamber 12 and the second condensation chamber 13 and contacts the first upper valve core 42 and the second upper valve core 43.

[0052] S4. After a sufficient amount of medium flows out of the discharge port 112, the control signal is input again to start the actuator to reset, driving the valve stem 3 to move downward and reset, so that the sealing valve core 41 abuts against the sealing valve seat 113 to block the flow of the medium. The first upper valve core 42 is separated from the first upper valve seat 114, and the second upper valve core 43 is separated from the second upper valve seat 123. The liquid medium in the second condensation chamber 13 flows into the first condensation chamber 12 from the second connecting hole 131, and the liquid medium in the first condensation chamber 12 flows into the valve chamber 11 from the first connecting hole 121 and remains at the bottom of the valve chamber 11.

[0053] Working principle: After the ultra-low temperature medium enters the valve chamber 11, the valve stem 3 and the valve core 4 generate heat during working friction and sliding, which is absorbed by the medium. Part of the medium vaporizes and penetrates into the first condensation chamber 12, and the first condensation plate 122 is started to cool the gaseous medium in the first condensation chamber 12 to make it liquid again. Part of the medium in the first condensation chamber 12 absorbs heat and vaporizes, and enters the second condensation chamber 13. The second condensation plate 132 is started to cool the gaseous medium in the second condensation chamber 13 to make it liquid again. When the regulating valve is closed, after the sealing valve core 41 contacts the sealing valve seat 113, the first upper valve core 42 and the second upper valve core 43 are separated from the first upper valve seat 114 and the second upper valve seat 123 respectively, so that the media in the second condensation chamber 13 and the first condensation chamber 12 flow back to the bottom of the valve chamber 11. When the regulating valve is opened next time, it is driven by the medium newly entering the valve chamber 11. Flowing to the discharge port 112, the heat generated by the opening and closing valve stem 3 and the valve core 4 of the regulating valve is limited. After condensation in the two condensation chambers, the medium volatilized into the sealing sleeve 5 is negligible, and the impact on the packing 51 is small, which can ensure the normal operation of the regulating valve and its sealing performance. The matching position of the valve core 4 and the valve body 1 is nickel-plated to improve the wear resistance of the connection between the valve core 4 and the valve body 1, thereby increasing the service life of the regulating valve. A cavity is set inside the second valve stem 32 and the valve core 4, and a heat-insulating material is set in the cavity to further reduce the heat generated by the second valve stem 32 and the valve core 4 when working, reduce the impact on the medium, and help improve the practicability of the regulating valve. The length of the sealing sleeve 5 is set, and the length of the packing 51 is guaranteed. Even if the medium leaks, it will take a certain amount of time for the packing 51 to completely fail, which buys time for later maintenance and further improves the practicability of the regulating valve.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cryogenic regulating valve, comprising a valve body (1), characterized in that: A valve cover (2) is fixedly mounted on the top of the valve body (1), a sealing sleeve (5) is fixedly mounted on the top of the valve cover (2), a pressure cover (6) is fixedly mounted on the top of the sealing sleeve (5), a valve stem (3) is passed through the pressure cover (6), the bottom of the valve stem (3) is passed through the sealing sleeve (5) and the valve body (1), a valve core (4) is fixedly mounted on one end of the valve stem (3) located in the valve body (1), and the valve core (4) is movably abutted against the valve body (1).

2. The ultra-low temperature regulating valve according to claim 1, characterized in that: The valve body (1) is provided with a valve chamber (11), a first condensation chamber (12), and a second condensation chamber (13) in sequence from bottom to top, and the valve chamber (11), the first condensation chamber (12), and the second condensation chamber (13) are connected to each other; The bottom of the valve cavity (11) penetrates through the bottom of the valve body (1) to form a feed inlet (111); one side of the valve cavity (11) penetrates through the side wall of the valve body (1) to form a discharge port (112); the bottom of the valve cavity (11) is provided with a sealing valve seat (113), the sealing valve seat (113) is communicated with the feed inlet (111); and the top of the valve cavity (11) is provided with a first upper valve seat (114); A first connecting hole (121) is provided at the bottom of the first condensing chamber (12), the first connecting hole (121) is connected to the first upper valve seat (114), a first condensing plate (122) is fixedly mounted on the inner wall of the first condensing chamber (12), and a second upper valve seat (123) is provided at the top of the first condensing chamber (12); A second connecting hole (131) is provided at the bottom of the second condensing chamber (13), and the second connecting hole (131) is connected to the second upper valve seat (123). A second condensing plate (132) is fixedly installed on the inner wall of the second condensing chamber (13), and the bottom of the valve cover (2) is movably connected to the top of the second condensing chamber (13).

3. The ultra-low temperature regulating valve according to claim 2, characterized in that: The valve core (4) comprises a sealing valve core (41), a first upper valve core (42), and a second upper valve core (43); the sealing valve core (41) is fixedly mounted on the bottom of the valve stem (3); the first upper valve core (42) and the second upper valve core (43) are both fixedly mounted on the valve stem (3); the first upper valve core (42) is located above the sealing valve core (41); the second upper valve core (43) is located above the first upper valve core (42); the sealing valve core (41) is movably abutted against the sealing valve seat (113); the first upper valve core (42) is movably abutted against the first upper valve seat (114); and the second upper valve core (43) is movably abutted against the second upper valve seat (123).

4. The ultra-low temperature regulating valve according to claim 1, characterized in that: The connection between the valve core (4) and the valve body (1) is nickel-plated.

5. The ultra-low temperature regulating valve according to claim 1, characterized in that: A packing (51) is provided in the sealing sleeve (5), and the packing (51) is in contact between the sealing sleeve (5) and the valve stem (3). The valve stem (3) is slidably connected to the packing (51). The bottom of the gland (6) is movably clamped on the top of the sealing sleeve (5), and the bottom of the gland (6) is movably in contact with the packing (51).

6. The ultra-low temperature regulating valve according to claim 1, characterized in that: The valve stem (3) comprises a first valve stem (31) and a second valve stem (32); the first valve stem (31) and the second valve stem (32) are welded and fixed to each other; the first valve stem (31) is located in the sealing sleeve (5) and the second valve stem (32) is located in the valve body (1).

7. The ultra-low temperature regulating valve according to claim 6, characterized in that: The second valve stem (32) and the valve core (4) are both hollow structures, and their cavities are interconnected, and the cavities are filled with heat insulation material.

8. The ultra-low temperature regulating valve according to claim 1, characterized in that: The top of the valve cover (2) is provided with a mounting groove (21), the bottom of the sealing sleeve (5) is inserted into the mounting groove (21), and the valve cover (2) and the sealing sleeve (5) are fixed by welding.

9. The ultra-low temperature regulating valve according to claim 1, characterized in that: The sealing sleeve (5) is longer than 50 cm.

10. A cryogenic regulating valve and a method of using the same, comprising the cryogenic regulating valve according to any one of claims 1 to 9, further comprising a pneumatic actuator and a valve positioner, wherein the pneumatic actuator is fixedly connected to the top of the valve stem (3), characterized in that: The following steps are also included: S1. First, assemble the regulating valve, evacuate the inside of the valve chamber (11), the first condensation chamber (12), and the second condensation chamber (13), connect the feed pipe of the medium to the feed port (111), connect the discharge port (112) to the discharge pipe of the medium, and install the pneumatic actuator and the valve positioner on the top of the regulating valve; S2, input a control signal to start the pneumatic actuator, which drives the valve stem (3) to move upward, the sealing valve core (41) separates from the sealing valve seat (113), the first upper valve core (42) abuts against the first upper valve seat (114), and the second upper valve core (43) abuts against the second upper valve seat (123), and the medium flows from the feed port (111) through the inside of the valve cavity (11) and out from the discharge port (112). S3, start the first condensation plate (122) and the second condensation plate (132) to condense the medium gas in the first condensation chamber (12) and the second condensation chamber (13) to form a liquid medium, which is concentrated at the inner bottom of the first condensation chamber (12) and the second condensation chamber (13) to contact the first upper valve core (42) and the second upper valve core (43). S4. After a sufficient amount of medium flows out of the discharge port (112), the control signal is input again to start the actuator to reset, driving the valve stem (3) to move downward to reset, and the sealing valve core (41) abuts against the sealing valve seat (113) to block the flow of the medium. The first upper valve core (42) is separated from the first upper valve seat (114), and the second upper valve core (43) is separated from the second upper valve seat (123). The liquid medium in the second condensation chamber (13) flows from the second connecting hole (131) into the first condensation chamber (12), and the liquid medium in the first condensation chamber (12) flows from the first connecting hole (121) into the valve chamber (11) and remains at the bottom of the valve chamber (11).

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