A liquid helium transmission device, a liquid helium system, and a transmission method

Abstract

The present invention discloses a liquid helium transmission device, a liquid helium system, and a transmission method, which include a liquid helium tube, a helium gas tube, and a vacuum tube sleeved from the inside out in sequence to form a transmission tube; the two ends of the transmission tube have an increasing length from the outside to the inside; intake holes and exhaust holes are respectively opened on the tube segments of the two ends of the helium gas tube located outside the vacuum tube; it also includes a socket tube; the socket tube is detachably sleeved on the liquid inlet end of the transmission tube; the end of the liquid helium tube is in sealed cooperation with the end of the socket tube, so that the liquid inlet of the liquid helium tube is communicated with the liquid inlet of the socket tube; a helium gas return port is also opened on the tube wall of the socket tube and is communicated with the exhaust hole of the helium gas tube. The sealing of the present invention and the design of the transmission tube end increasing from the outside to the inside in sequence cooperate to achieve a series of operations such as quick socket fixing, liquid infusion, reflux, and heat exchange. The structure design is ingenious and easy to implement, reduces helium gas transfer, reduces helium gas loss, maximally utilizes the cold quantity of helium gas, and improves the liquid helium transmission efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid helium transportation equipment, and specifically relates to a liquid helium transmission device, a liquid helium system, and a transmission method. Background Art

[0002] As an important part of the national large scientific device - the steady-state strong magnetic field device, the helium cryogenic system provides liquid helium for a series of low-temperature and superconducting magnet experimental equipment, meeting the requirements of the large scientific device for liquid helium and liquid helium at different temperature ranges. In the helium liquefier, an important device for providing liquid helium in the helium cryogenic system, a liquid helium transfer pipe is required to input the generated liquid helium into the liquid helium dewar. Due to the particularity of liquid helium, with a boiling point of -269 °C, it is particularly easy to vaporize. Especially during the transmission process, a large amount of liquid helium will vaporize, resulting in low transmission efficiency.

[0003] The utility model with the publication number CN2270153Y discloses a liquid helium transmission dewar tank with a heat exchanger. Its structure is mainly that an inner pipe is sleeved with a reflux pipe, and the reflux pipe is further sleeved with an outer pipe. Inside the outer pipe, a heat exchanger is added on the pipelines of the inner pipe and the reflux pipe. The refluxing helium gas is used to cool the liquid helium to reduce the vaporization of the liquid helium, and the refluxing helium gas is transported to the gas holder. This liquid helium transmission dewar is suitable for the liquid helium transmission between two liquid helium dewars. In this structure, the refluxing helium gas requires a separate collection container. For the scenario of directly transporting liquid helium from a liquid helium refrigerator to a dewar, the pipeline disclosed by this utility model cannot achieve rapid assembly, and there is a risk of leakage in the intermediate storage of helium gas. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to provide a liquid helium transmission device that integrates rapid assembly, liquid helium transmission, helium gas reflux, and heat exchange.

[0005] The present invention solves the above technical problems through the following technical means:

[0006] A liquid helium transmission device includes a liquid helium pipe, a helium gas pipe, and a vacuum pipe sleeved from the inside out in sequence to form a transmission pipe; the two ends of the transmission pipe increase in length from the outside to the inside; the two ends of the helium gas pipe are hermetically arranged with the wall of the liquid helium pipe, and air inlet holes and exhaust holes are respectively opened on the pipe sections of the two ends of the helium gas pipe located outside the vacuum pipe; the two ends of the vacuum pipe are hermetically arranged with the wall of the helium gas pipe;

[0007] It further includes a socket pipe; the socket pipe is detachably sleeved on the liquid inlet end of the transmission pipe; the end of the liquid helium pipe is hermetically fitted with the end of the socket pipe, so that the liquid inlet of the liquid helium pipe is communicated with the liquid inlet of the socket pipe; a helium gas reflux port is further opened on the wall of the socket pipe, which is communicated with the exhaust hole of the helium gas pipe.

[0008] The infusion tube is fixed by means of socket connection, enabling a solution where the infusion tube can be freely inserted and removed. Multiple reflux exhaust holes are opened at the bottom of the helium tube. The refluxing cold helium gas flows back into the exhaust pipeline through the reflux exhaust holes, ensuring unobstructed reflux exhaust. During actual application, the helium gas directly flows back into the helium refrigerator, reducing leakage losses occurring in intermediate helium storage and lowering costs. The use of a sealant in abutment with the socket tube, and achieving sealing by utilizing the deformation amount of the sealant, provides good sealing effect and simple operation, which is the key point for implementing the socket connection structure. The design of the seal and the gradually increasing lengths from the outside to the inside at the end of the transmission tube in the present invention collaboratively achieve a series of operations including rapid socket connection and fixation, infusion, reflux, and heat exchange. The structural design is ingenious and easy to implement, reducing helium transfer, lowering helium losses, maximizing the utilization of helium cold energy, and improving the liquid helium transmission efficiency.

[0009] Further, a sealant is fixed on the tube wall of the liquid helium inlet of the liquid helium tube, and the sealant is in sealing abutment with the inner wall of the liquid helium inlet of the socket tube.

[0010] Further, the intake end of the socket tube is a reduced-diameter section.

[0011] Further, the reduced-diameter section is a conical section.

[0012] Further, the socket tube and the transmission tube are fixed by a flange.

[0013] Further, the transmission tube has a flexible section.

[0014] Further, in the flexible section, the liquid helium tube and the helium tube adopt bellows, and the vacuum tube adopts a stainless steel braided net tube.

[0015] Further, a support frame is installed between the helium tube and the vacuum tube.

[0016] The present invention also provides a liquid helium system, including a helium refrigeration side, a liquid helium storage side, and the above-mentioned liquid helium transmission device; the helium refrigeration side includes an infusion port, the socket tube is fixed to the infusion port, and liquid helium reaches the liquid helium storage side through the socket tube and the transmission tube; the helium gas on the liquid helium storage side enters the helium tube from the intake port of the helium tube, is discharged from the exhaust port of the helium tube, and enters the helium refrigeration side from the helium gas reflux port of the socket tube.

[0017] Further, the present invention also provides a liquid helium transmission method for the liquid helium system, including the following steps:

[0018] S1. Fix the socket tube to the infusion port of the helium refrigeration side, then insert the liquid inlet end of the transmission tube into the socket tube, and fix the two by a flange. At this time, the sealant at the liquid inlet end of the liquid helium tube is in sealing abutment with the liquid inlet of the socket tube;

[0019] S2. Insert the liquid outlet end of the transmission tube into the liquid helium storage side and fix it;

[0020] S3. Evacuate the vacuum tube;

[0021] S4. Transport liquid helium. The helium gas on the liquid helium storage side flows back to the helium refrigeration side through the helium gas pipe.

[0022] The advantages of the present invention are as follows:

[0023] The infusion tube is fixed by the socket connection method of the infusion tube, and the scheme of free plugging and unplugging of the infusion tube can be realized. Multiple reflux exhaust holes are opened at the bottom of the helium gas pipe, and the refluxing cold helium gas flows back into the exhaust pipeline through the reflux exhaust holes, ensuring the smoothness of reflux exhaust. In practical applications, the helium gas directly flows back into the helium refrigerator, reducing the leakage loss during the intermediate storage of helium gas and lowering the cost. The use of the abutment of the seal and the socket tube, and the use of the deformation amount of the seal to achieve sealing, has good sealing effect and simple operation, which is the key point to realize the socket structure. The design of the present invention with the seal and the gradually increasing length from the outside to the inside of the end of the transmission tube jointly realizes a series of operations of rapid socket fixing, infusion, reflux, and heat exchange. The structure design is ingenious and easy to implement, reduces the helium gas transfer, reduces the helium gas loss, makes the best use of the cold quantity of helium gas, and improves the liquid helium transmission efficiency.

[0024] The infusion inner tube in the horizontal section of the infusion tube, the helium gas pipe is connected by a corrugated pipe while the vacuum outer tube uses a stainless steel braided mesh, which is convenient for assembly. At the same time, the corrugated pipe of the liquid helium tube increases the heat exchange area and improves the liquid helium infusion efficiency. Brief Description of the Drawings

[0025] Figure 1 It is the overall structure schematic diagram of the liquid helium system in Embodiment 2 of the present invention;

[0026] Figure 2 It is Figure 1 The enlarged view of part A in

[0027] Figure 3 It is the support frame structure schematic diagram in the embodiment of the present invention. Detailed Embodiment

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] Embodiment 1

[0030] This embodiment provides a liquid helium transfer device, which includes a liquid helium pipe 1, a helium gas pipe 2, and a vacuum pipe 3 sleeved from the inside out in sequence to form a three-layer transfer pipe; the two ends of the transfer pipe increase in length from the outside to the inside, the two ends of the helium gas pipe 2 are hermetically arranged with the pipe wall of the liquid helium pipe 1, and air inlet holes 21 and exhaust holes 22 are respectively opened on the pipe sections of the two ends of the helium gas pipe 2 located outside the vacuum pipe 3; the two ends of the vacuum pipe 3 are hermetically arranged with the pipe wall of the helium gas pipe 2; the outer wall of the helium gas pipe 2 is wrapped with multiple layers of heat insulation to reduce the influence of heat radiation on heat leakage, avoid heat leakage losses caused by heat convection and heat radiation in extremely low temperatures, effectively reduce the heat leakage in the pipeline, and reduce the losses in liquid helium conduction. In order to further avoid heat leakage losses caused by heat conduction, an epoxy support frame 4 made of G10 material with a low thermal conductivity is installed between the second-layer helium gas pipe 2 and the third-layer vacuum outer pipe. The support frame 4 is generally cross-shaped and is a plate-like structure with four points in contact with the third-layer vacuum pipe 3. The support frame 4 is sleeved outside the multiple layers of heat insulation wrapped on the second-layer helium gas pipe 2. By winding multiple layers of heat insulation with an appropriate thickness, the second-layer helium gas pipe 2 and the third-layer vacuum pipe 3 can be well fixed to each other, avoiding heat conduction heat leakage caused by the collision of the two pipe walls. This structure has a large support strength and a small cross-sectional area, effectively reducing the heat leakage caused by heat conduction.

[0031] It also includes a socket pipe 5; the socket pipe 5 is detachably sleeved on the liquid inlet end of the transfer pipe; the end of the liquid helium pipe 1 is hermetically fitted with the end of the socket pipe 5, so that the liquid inlet of the liquid helium pipe 1 is communicated with the liquid inlet of the socket pipe 5; a helium gas return port 51 is also opened on the pipe wall of the socket pipe 5 and is communicated with the exhaust hole 22 of the helium gas pipe 2.

[0032] The sealing and fixing measures for the liquid inlet end of the liquid helium pipe 1 and the socket pipe 5 in this embodiment are as follows:

[0033] A seal 11 is fixed on the pipe wall of the liquid inlet of the liquid helium pipe 1. The liquid inlet of the socket pipe 5 is a reduced-diameter section, such as a stepped section or a tapered section. The seal 11 is a cylindrical sleeve made of polyvinylidene fluoride and is sleeved on the liquid inlet of the liquid helium pipe 1 and is hermetically abutted against the inner wall of the reduced-diameter section of the liquid inlet of the socket pipe 5. Quick sealing is achieved through the deformation of the seal 11. The other end of the socket pipe 5 is fixed to the vacuum pipe 3 through a clamp flange 6. As long as the clamp flange 6 is unlocked, the transfer pipe can be pulled out of the socket pipe 5, and the assembly is simple and easy to operate.

[0034] Further, the horizontal section of the transfer pipe is generally vertically connected to the helium refrigeration side and the liquid helium storage side through elbows. Since the relative positions of the helium refrigeration side and the liquid helium storage side are fixed, it is very difficult to plug and unplug the transfer pipe by using a hard connection method. Therefore, a flexible section 10 is designed for the transfer pipe. In this embodiment, the liquid helium pipe 1 and the helium gas pipe 2 at the horizontal section of the transfer pipe are connected by bellows, and the vacuum outer pipe uses a stainless steel braided mesh. This flexible connection can facilitate the plugging and unplugging of the transfer pipe even when there is a slight deviation in the size of the horizontal section of the transfer pipe. At the same time, the bellows can increase the heat exchange area and improve the liquid helium infusion efficiency. Other flexible material pipelines are also applicable to this embodiment, but the bellows have a larger heat exchange area and are the best choice for this embodiment.

[0035] In this embodiment, the vacuum pumping port 31 of the vacuum pipe 3 is communicated with a vacuum pumping device.

[0036] Embodiment 2

[0037] This embodiment applies the transfer device of Embodiment 1 to design a liquid helium system, including a helium refrigeration side 20, a liquid helium storage side 30, and the liquid helium transfer device of Embodiment 1; the helium refrigeration side 20 is a helium refrigerator, including an infusion port. The receiving pipe 5 is fixed to the infusion port. Liquid helium reaches the liquid helium storage side 30 (liquid helium dewar) through the receiving pipe 5 and the transfer pipe; the helium gas on the liquid helium storage side 30 enters the helium gas pipe 2 from the air inlet hole 21 of the helium gas pipe 2, discharges from the exhaust hole 22 of the helium gas pipe 2, and enters the helium refrigeration side 20 from the helium gas return port 51 of the receiving pipe 5. In this way, the cold energy of the helium gas can be used to cool the liquid helium, reducing the loss of liquid helium, and the helium gas can be directly returned to the helium refrigeration side 20, reducing the setting of other equipment. In this embodiment, the receiving pipe 5 can be permanently fixed on the helium refrigerator. When it is necessary to transport liquid helium, the transfer pipe is directly inserted into the receiving pipe 5 and fixed by a clamp flange 6. The other end of the transfer pipe is hermetically fixed to the neck of the liquid helium dewar, and the fixing method can be a flange, a joint lock nut, etc.

[0038] This embodiment also provides a liquid helium transfer method for the liquid helium system, including the following steps:

[0039] S1. Fix the receiving pipe 5 to the infusion port of the helium refrigeration side 20, then insert the liquid inlet end of the transfer pipe into the receiving pipe 5 and fix the two by a flange. At this time, the seal 11 at the liquid inlet end of the liquid helium pipe 1 is in sealing contact with the liquid inlet of the receiving pipe 5;

[0040] S2. Insert the liquid outlet end of the transfer pipe into the liquid helium storage side 30 and fix it;

[0041] S3. Evacuate the vacuum pipe 3;

[0042] S4. Transport liquid helium. The helium gas on the liquid helium storage side 30 returns to the helium refrigeration side 20 through the helium gas pipe 2. So far, the liquid helium transfer is introduced.

[0043] This embodiment realizes line sealing by using the conical sealing surface of the infusion tube socket and the polytetrafluoroethylene cylindrical bushing. This sealing method has a tight seal, is not affected by temperature changes, and can achieve the sealing of liquid helium and helium gas in a cryogenic environment.

[0044] Multiple reflux exhaust holes 22 are opened at the bottom of the helium gas pipe 2. The refluxing cold helium gas flows back into the exhaust pipeline through the reflux exhaust holes 22, ensuring the smoothness of reflux exhaust.

[0045] An epoxy support made of G10 material with a low thermal conductivity is installed between the second-layer helium gas pipe 2 and the third-layer vacuum pipe 3. This structure has a large support strength and a small cross-sectional area, effectively reducing the heat leakage caused by heat conduction.

[0046] Through the three-layer sleeve method, the cold helium gas refluxing from the liquid helium dewar can exchange heat with the incoming liquid helium through the cold helium gas pipe 2, and re-liquefy the partially vaporized liquid helium. This solves the problem of low liquid helium transmission efficiency and realizes the reuse of the cold energy of the cold helium gas.

[0047] The infusion tube is fixed by using the socket method of the infusion tube, and the scheme of free plugging and unplugging of the infusion tube can be realized.

[0048] In the horizontal section of the infusion tube, the inner infusion tube and the helium gas pipe 2 are connected by a corrugated pipe, while the outer vacuum tube uses a stainless steel braided mesh, which is convenient for assembly. At the same time, the corrugated pipe of the liquid helium pipe 1 increases the heat exchange area and improves the liquid helium infusion efficiency.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A liquid helium transfer device, characterized in that, It includes a liquid helium tube (1), a helium gas tube (2), and a vacuum tube (3) which are sleeved from the inside out in sequence to form a transmission tube; both ends of the transmission tube increase in length from the outside to the inside; both ends of the helium gas tube (2) are hermetically arranged with the tube wall of the liquid helium tube (1), and intake holes (21) and exhaust holes (22) are respectively opened on the tube segments of both ends of the helium gas tube (2) located outside the vacuum tube (3); both ends of the vacuum tube (3) are hermetically arranged with the tube wall of the helium gas tube (2). It further includes a socket tube (5); the socket tube (5) is detachably sleeved on the liquid inlet end of the transmission tube; the end of the liquid helium tube (1) is hermetically fitted with the end of the socket tube (5) so that the liquid inlet of the liquid helium tube (1) is communicated with the liquid inlet of the socket tube (5); a helium gas return port (51) is also opened on the tube wall of the socket tube (5), which is communicated with the exhaust hole (22) of the helium gas tube (2).

2. The liquid helium transfer device according to claim 1, characterized in that, A seal (11) is fixed on the tube wall of the liquid inlet of the liquid helium tube (1), and the seal (11) is hermetically abutted against the inner wall of the liquid inlet of the socket tube (5).

3. The liquid helium transfer device according to claim 2, characterized in that, The intake end of the socket tube (5) is a reduced-diameter section.

4. The liquid helium transfer device according to claim 3, characterized in that, The reduced-diameter section is a tapered section.

5. The liquid helium transfer device according to any one of claims 1 to 4, characterized in that, The socket tube (5) and the transmission tube are fixed by a flange.

6. The liquid helium transfer device according to any one of claims 1 to 4, characterized in that, The transmission tube has a flexible section (10).

7. The liquid helium transfer device according to claim 6, characterized in that, In the flexible section (10), the liquid helium tube (1) and the helium gas tube (2) adopt bellows, and the vacuum tube (3) adopts a stainless steel braided net tube.

8. The liquid helium transfer device according to any one of claims 1 to 4, characterized in that, A support frame (4) is installed between the helium gas tube (2) and the vacuum tube (3).

9. A liquid helium system, characterized in that, It includes a helium refrigeration side (20), a liquid helium storage side (30), and the liquid helium transmission device according to any one of claims 1 to 8; the helium refrigeration side (20) includes a liquid inlet, the socket tube (5) is fixed to the liquid inlet, and liquid helium reaches the liquid helium storage side (30) through the socket tube (5) and the transmission tube; the helium gas of the liquid helium storage side (30) enters the helium gas tube (2) from the intake port of the helium gas tube (2), is discharged from the exhaust port of the helium gas tube (2), and enters the helium refrigeration side (20) from the helium gas return port (51) of the socket tube (5).

10. A liquid helium transfer method applied to the liquid helium system according to claim 9, characterized in that, It includes the following steps: S1. Fix the socket tube (5) to the liquid inlet of the helium refrigeration side (20), then insert the liquid inlet end of the transmission tube into the socket tube (5), and fix the two by a flange. At this time, the seal (11) at the liquid inlet end of the liquid helium tube (1) is hermetically abutted against the liquid inlet of the socket tube (5). S2. Insert the liquid outlet end of the transmission tube into the liquid helium storage side (30) and fix it. S3. Vacuumize the vacuum tube (3). S4. Transport liquid helium, and the helium gas of the liquid helium storage side (30) flows back to the helium refrigeration side (20) through the helium gas tube (2).

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