CN220205413U - Level gauge mounting structure - Google Patents

Abstract

The utility model discloses a verifying device of a supercritical helium pressure stabilizing system, which comprises a liquid helium unit, a liquid nitrogen unit, a helium cylinder, a storage dewar, an evacuating pump set and a rewarming pressurizing device, wherein the storage dewar is of a double-layer cavity structure, and a gap is reserved between an inner cavity and an outer cavity of the storage dewar to form a vacuum cavity. In the utility model, the storage dewar can be precooled by connecting the liquid nitrogen unit with the storage dewar and introducing low-temperature liquid nitrogen in the storage dewar, the precooled liquid nitrogen can be purged by connecting the helium bottle with the storage dewar, meanwhile, the liquid nitrogen is also used for pressurizing the subsequent supercritical helium storage dewar, an interlayer formed by a gap between the double-layer cavities can be vacuumized by arranging the evacuation pump group, and the evacuation replacement is carried out after the storage dewar is precooled, and the low-temperature cold helium gas for pressurizing can be changed into room-temperature helium gas by arranging the rewarming device, so that a set of verifying device for heating and pressurizing the supercritical helium is formed.

Description

Level gauge mounting structure

Technical Field

The utility model relates to the technical field of rocket ground test equipment, in particular to a liquid level meter mounting structure.

Background

Helium is used as a common pressurizing gas, has the characteristics of small molecular weight and stable chemical property, and is widely applied to pressurizing systems of liquid carrier rockets and spacecrafts. In order to store more helium in the same spatial structure, a supercritical helium warming and pressurizing system is the optimal choice. Such a pressurizing system is to liquefy helium gas at its critical pressure and critical temperature state and store it in low pressure liquid helium, thereby obtaining a relatively high density and light storage container. During operation, liquid helium is heated and pressurized to be converted into a special form between liquid and gas, and then heated and vaporized by a warmer and sent to a propellant tank for pressurization. The pressurizing form can greatly reduce the weight of the system, and the safety of the rocket and the spacecraft is improved due to the smaller working pressure of the system. Supercritical helium warming and pressurizing technology has been successfully applied to the degradation of the Apollo lunar bay and the first level of Alean V abroad.

Various pressurizing schemes are adopted for the liquid rocket storage tanks at home and abroad, wherein a supercritical helium heating pressurizing scheme is adopted for the primary liquid oxygen tank of the Arian V rocket. The supercritical helium heating and pressurizing device is the only example of successfully applying supercritical helium heating and pressurizing in the world, and is also one of the main technical characteristics of the Arian V rocket.

The supercritical helium heating and pressurizing technology is successfully applied to the degradation of an Apollo lunar bay and the first stage of Alean V in foreign countries, but is not applied in China, and in order to apply the supercritical helium pressurizing technology to future rockets in China, the performance and the matching performance of a rocket supercritical helium heating and pressurizing system are necessary to be researched.

When the device is used in a supercritical helium pressure stabilizing system verification device, the actual liquid level in the inner cavity of the storage dewar is required to be measured through the liquid level meter, and since the existing liquid level meter is directly inserted into the inner cavity of the storage dewar when in use, a supporting outer tube is required to be added to protect the liquid level meter and provide space for the liquid level meter, the supporting outer tube is of a full-sealing design, but helium is generated continuously along with filling of liquid helium, if the helium is not discharged in time, du Wabie pressure is easily caused to be stored, danger is generated, meanwhile, cold shrinkage can occur on the supporting outer tube due to continuous input of low-temperature liquid helium and helium, and the whole structure can be damaged when the cold shrinkage of the supporting outer tube is overlarge.

Disclosure of Invention

The utility model aims to solve the technical problem of how to prevent the helium generated during liquid helium filling from generating pressure holding of the whole storage Dewar.

The utility model solves the technical problems by the following technical means: the utility model provides a level gauge mounting structure, includes neck pipe assembly, level gauge assembly, neck pipe assembly axial is equipped with first airtight cavity structure and the airtight cavity structure of second in proper order, neck pipe assembly top is located to the level gauge assembly is fixed, the level gauge assembly is including the mounting tube that runs through first airtight cavity structure and the airtight cavity structure of second, the connecting hole that is linked together with first airtight cavity structure has been seted up to the one section that the mounting tube is located first airtight cavity structure, the mounting tube passes through connecting hole, the airtight cavity structure of first and outside exhaust line intercommunication.

Through offer the intercommunicating pore on the installation pipe to communicate with outside exhaust line through first airtight cavity structure, can prevent to appear holding down the pressure danger.

As the preferable technical scheme, outer chamber subassembly top is equipped with the ring flange, neck pipe subassembly includes outer tube, inner tube, intermediate transition flange, top transition flange, outer tube fixed connection is at the ring flange top, the inner tube is through intermediate transition flange fixed in locating the outer tube, outer tube top fixedly connected with top transition flange, outer tube inner wall, intermediate transition flange enclose and close and form first airtight cavity structure, intermediate transition flange, outer tube inner wall, inner tube outer wall form the airtight cavity structure of second.

As the preferable technical scheme, inner chamber subassembly top is equipped with the connection lug, the level gauge subassembly includes the level gauge erection joint, fixedly connected with level gauge erection joint on the top transition flange, the level gauge erection joint is used for carrying out the side seal to the level gauge and fixes.

As the preferable technical scheme, the liquid level meter assembly further comprises a connecting corrugated pipe, the mounting pipe comprises a first mounting pipe and a second mounting pipe, the top end of the first mounting pipe is fixedly connected with the liquid level meter mounting joint, and the first mounting pipe is fixedly connected with the second mounting pipe through the connecting corrugated pipe.

As the preferred technical scheme, the liquid level meter installation joint includes butt joint pipe, sealing nut, pressure pad, liquid level meter sealing washer, the butt joint pipe, sealing nut, pressure pad, liquid level meter sealing washer center department all offered with the mounting hole of liquid level meter looks adaptation, sealing nut and butt joint pipe spin are connected, and still are equipped with pressure pad and liquid level meter sealing washer between sealing nut and the butt joint pipe.

The pressing pad can be pressed by the rotary sealing nut, and then the sealing ring of the liquid level meter is pressed by the pressing pad, so that the sealing ring of the liquid level meter is forced to deform towards the trapezoid concave hole, and side sealing and fixing of the liquid level meter are realized.

As an optimal technical scheme, the top of the butt joint pipe is provided with a trapezoid concave hole.

As an optimal technical scheme, the top of the top transition flange is fixedly connected with a liquid injection joint.

As the preferable technical scheme, the liquid level meter packaging head and the liquid level meter sealing gasket are further included, the liquid level meter packaging head is connected with the butt joint pipe in a screwed mode, and the liquid level meter sealing gasket is located between the liquid level meter packaging head and the butt joint pipe.

The utility model has the advantages that:

(1) According to the utility model, the communication hole is formed in the mounting pipe and is communicated with the external exhaust pipeline through the first closed cavity structure, so that the occurrence of pressure holding danger can be prevented.

(2) According to the utility model, the rotary sealing nut can press the pressing pad, so that the sealing ring of the liquid level meter is pressed by the pressing pad, and the sealing ring of the liquid level meter is forced to deform towards the trapezoid concave hole, so that the side sealing and fixing of the liquid level meter are realized.

Drawings

FIG. 1 is a schematic diagram of an overall structure according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of a storage Dewar according to an embodiment of the present utility model;

FIG. 3 is a schematic diagram of an internal structure of a storage Dewar according to an embodiment of the present utility model;

fig. 4 is a schematic structural diagram of a first closed cavity according to an embodiment of the present utility model;

FIG. 5 is a schematic view of an infusion tube connector assembly according to an embodiment of the present utility model;

FIG. 6 is a schematic cross-sectional view of an infusion tube connector assembly according to an embodiment of the present utility model;

FIG. 7 is a schematic view of an external cavity assembly according to an embodiment of the present utility model;

FIG. 8 is a schematic view of a cavity assembly according to an embodiment of the present utility model;

FIG. 9 is a schematic view of a mounting joint of a level gauge according to an embodiment of the present utility model;

FIG. 10 is a schematic cross-sectional view of a fitting for a level gauge according to an embodiment of the present utility model;

reference numerals: 1. liquid helium Dewar; 11. a liquid helium filling pipe; 2. liquid nitrogen Dewar; 21. a liquid nitrogen filling pipe; 3. a helium cylinder; 31. a helium gas filling pipe; 311. filling a ball valve; 4. an air bath heat exchanger; 5. evacuating the pump group; 6. storing Dewar; 61. an outer chamber assembly; 611. an outer cavity upper hemisphere; 612. an outer cavity lower hemisphere; 613. a base support; 62. an inner chamber assembly; 621. an inner cavity upper hemisphere; 622. a lower hemisphere of the inner cavity; 63. a flange plate; 64. an insulation assembly; 65. the connecting lifting lug; 651. a horizontal section; 652. a vertical section; 66. transporting the tool; 661. a screw; 662. fixing a tooling flange plate; 663. sealing the flange plate; 664. a flange connecting pipe; 7. a neck assembly; 71. an outer tube; 72. an inner tube; 73. an intermediate transition flange; 74. a top transition flange; 75. an infusion tube joint assembly; 751. a tube seat; 7511. butting round platforms; 752. a screw cap; 7521. an annular hole; 753. a compression ring; 7531. a groove; 754. a rubber ring; 76. a level gauge assembly; 761. a liquid level gauge; 762. a level gauge packaging head; 763. installing a pipe; 7631. a first mounting tube; 7632. a second mounting tube; 7633. a communication hole; 764. connecting a corrugated pipe; 765. a liquid level meter mounting joint; 7651. a butt joint pipe; 7652. a sealing nut; 7653. a pressing pad; 7654. a liquid level meter sealing ring; 76511. trapezoidal concave holes; 8. an electronic scale; 9. a heater; 10. a liquid injection pipe; 101. a first vacuum line; 1011. a first ball valve; 1012. vacuum diaphragm ball valve; 1013. a safety valve; 102. a second evacuation line; 1021. a second ball valve; 103. a rewarming pressurizing pipeline; 1031. a rewarming pipeline ball valve; 1032. a pressure sensor; 1033. an exhaust valve; 104. an exhaust line; 1041. an exhaust ball valve; 1042. and switching the ball valve.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions in the embodiments of the present utility model will be clearly and completely described in the following in conjunction with the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1, a verifying device of a supercritical helium pressure stabilizing system comprising a liquid helium unit, a liquid nitrogen unit, a helium bottle 3, a storage dewar 6, an evacuating pump set 5, a rewarming pressurizing device and an electronic platform scale 8, wherein the storage dewar 6 is of a double-layer cavity structure, a gap is reserved between an inner cavity and an outer cavity of the storage dewar 6 and forms an interlayer, the interlayer is a vacuum cavity, the interlayer is set into the vacuum cavity and can reduce heat leakage, the evacuating pump set 5 is respectively communicated with the interlayer of the storage dewar 6 and an inner cavity of the storage dewar 6, an input end at the top of the storage dewar 6 is respectively connected with the liquid helium unit, the liquid nitrogen unit and the helium bottle 3, control valves are respectively arranged on connecting pipes of the evacuating pump set 5, the rewarming pressurizing device and the exhaust pipeline 104 are respectively connected, a weight detecting device is further arranged at the bottom of the storage dewar 6, and the bottom of the outer cavity assembly 61 is fixed at the top of the electronic platform scale 8 through a plurality of base supports 613 distributed at equal angles.

Referring to fig. 2 and 3, the storage dewar 6 includes an outer cavity assembly 61, an inner cavity assembly 62, a flange 63, and an insulation assembly 64, the outer cavity assembly 61 is wrapped outside the inner cavity assembly 62, a gap is left between the outer cavity assembly 61 and the inner cavity assembly 62, and an interlayer is formed, the insulation assembly 64 is filled in the interlayer, in this embodiment, the insulation assembly 64 is an insulation wrapping layer, and includes 40 layers of insulation films, and the inner cavity of the inner cavity assembly 62 for storing the dewar is a vacuum cavity; the outer cavity assembly 61 and the inner cavity assembly 62 are spherical, and the wall thickness is 3mm;

in the embodiment, the inner diameter of the inner cavity of the storage Dewar 6 is 650mm, and the wall thickness is 3mm; the length of the neck pipe is 500mm, the inner diameter is 25.4mm, the wall thickness is 2mm, and the heat leakage is reduced by prolonging the length of the neck pipe assembly 7; the inner diameter of the outer cavity is 850mm, the wall thickness is 3mm, and the inner cavity of the Dewar 6 is stored.

Dewar inner cavity leakage heat statistics referring to the following table

The Dewar inner chamber 6 storage time calculation:

the volume of liquid helium in the spherical container when it is fitted to the neck is 143.7L, assuming an initial state t1=4.5k, a pressure p1=1.29 bara, a liquid density of 118.81g/L, an enthalpy value of 1.575kJ/kg, a total mass of 16kg; when the pressure P2=22 bara and the temperature T2=9.66K are in the state 2, the density is still 118.81g/L, and the enthalpy value is 35.23kJ/kg; the enthalpy difference values of state 2 and state 1 are: 33.63kJ/kg, helium heat capacity: cp1 = 639kJ; querying NIST website to obtain the aluminum material with the integral heat capacity of 18.7J/kg from 4.5K to 9.66K, wherein the total mass of the spherical cavity of the inner container is 34.95kg, and the total heat capacity of the inner cavity is as follows: cp2 = 653J; storage time t= (Cp 2+ Cp 1)/q=61.44 hours.

Referring to fig. 7, the outer cavity assembly 61 includes an outer cavity upper hemisphere 611, an outer cavity lower hemisphere 612, and a base support 613, the outer cavity upper hemisphere 611 is fixedly connected with a flange 63 by welding, the outer cavity upper hemisphere 611 and the outer cavity lower hemisphere 612 are enclosed and then fixedly welded to form a sealed spherical cavity structure, the bottom of the outer cavity lower hemisphere 612 is fixedly welded with three base supports 613, and the outer cavity assembly 61 is fixed at the top of the electronic scale 8 by the base supports 613;

referring to fig. 8, the inner cavity assembly 62 includes an inner cavity upper hemisphere 621 and an inner cavity lower hemisphere 622, the inner cavity upper hemisphere 621 and the inner cavity lower hemisphere 622 are welded and fixed after being enclosed to form a sealed spherical cavity structure, and the inner cavity assembly 62 is suspended at the bottom of the flange 63 and is located in the outer cavity assembly 61; the inner chamber upper hemisphere 621 top is equipped with connects lug 65, connects lug 65 and includes horizontal segment 651 and vertical segment 652, and vertical section 652 of perpendicular fixedly connected with is formed U type structure respectively at horizontal segment 651 both ends, and the free end of connecting lug 65 two vertical segments 652 is all fixed with the outer wall of inner chamber upper hemisphere 621, and its horizontal segment 651 passes through the bolt and is connected fastening with ring flange 63.

The device also comprises a transportation tool 66, wherein the transportation tool 66 comprises a screw 661, a fixed tool flange 662, a sealing flange 663 and a flange connecting pipe 664; the outer wall of the outer cavity lower hemisphere 612 is fixedly connected with three equiangular distribution flange connecting pipes 664, the free end of each flange connecting pipe 664 is fixedly connected with a fixed tooling flange 662, each fixed tooling flange 662 is connected with a screw rod 661 in a screwing mode, the three screw rods 661 are all abutted to the inner cavity lower hemisphere 622, when the outer cavity lower hemisphere is transported to the site, the three screw rods 661 are screwed out, the sealing flange 663 is fixedly connected with the fixed tooling flange 662 through bolts, and a copper pad is further arranged between the sealing flange 663 and the fixed tooling flange 662.

The welding of the storage dewar 6 comprises the following steps:

(1) The lumen assembly 62 is first connected to the neck tube assembly 7 and the level gauge assembly 76:

the inner cavity upper hemisphere 621, the inner tube 72 and the mounting tube 763 are welded and fixed, the connecting lifting lug 65 is welded and fixed at the top of the inner cavity upper hemisphere 621, and the inner cavity lower hemisphere 622 is fixedly connected with the inner cavity upper hemisphere 621;

(2) The outer cavity upper hemisphere 611 is assembled and welded with the inner cavity assembly 62:

the top of the outer cavity upper hemisphere 611 is welded with a flange 63, the top of the flange 63 is welded with a second evacuation pipeline 102, a second ball valve 1021, a vacuum gauge and a resistance gauge are arranged, and the top of the flange 63 is welded with a fixed neck pipe assembly 7; the connecting lifting lug 65 of the inner cavity assembly 62 is fixedly connected with the flange plate 63 through bolts;

(3) Assembling and welding the outer cavity upper hemisphere 611 and the outer cavity lower hemisphere 612 and the base support 613;

(4) Welding an external pipeline:

the rewarming pressurizing pipeline 103, the first vacuumizing pipeline 101 and the exhaust pipeline 104 are connected with the first closed cavity structure.

Referring to fig. 2, 4 and 8, a neck tube assembly 7 is fixedly connected to the top of the flange 63, the bottom of the neck tube assembly 7 penetrates through the flange 63 and is connected with an input end of the top of the inner cavity assembly 62 of the storage dewar 6, the neck tube assembly 7 comprises an outer tube 71, an inner tube 72, an intermediate transition flange 73, a top transition flange 74, an infusion tube joint assembly 75 and a liquid level meter assembly 76, the outer tube 71 is fixedly connected to the top of the flange 63, the outer tube 71 is of a tubular structure with two ends penetrating through and circumferentially closed, the bottom of the outer tube 71 is fixed to the flange 63, the top of the outer tube 71 is fixedly connected to the top transition flange 74 to form a closed cavity structure, the inner tube 72 is fixedly arranged in the outer tube 71 through the intermediate transition flange 73 and is divided into an upper closed cavity structure and a lower closed cavity structure, wherein the top transition flange 74, the inner tube wall 71 and the intermediate transition flange 73 enclose to form a first closed cavity structure, the intermediate transition flange 73, the inner tube wall 71 and the outer wall of the inner tube 72 form a second closed cavity structure and are communicated with an interlayer, and the inner tube 72 is communicated with the inner cavity assembly 62 through a telescopic bellows to counteract deformation of the inner tube 72 caused by low temperature cold contraction; the first airtight cavity structure is communicated with the inner cavity of the inner cavity assembly 62 through the inner pipe 72 and the telescopic bellows, a liquid level meter assembly 76 extending into the inner cavity assembly 62 is further arranged in the neck pipe assembly 7, and the liquid level meter assembly 76 is used for measuring the liquid level of liquid nitrogen and liquid helium in the inner cavity assembly 62.

Referring to fig. 1, fig. 2, fig. 5, the top of top transition flange 74 is through connecting ball valve (hereinafter referred to as V23) fixedly connected with infusion coupling subassembly 75, connecting ball valve one end links to each other with top transition flange 74, the other end links to each other with infusion coupling subassembly 75, infusion coupling subassembly 75 includes tube socket 751, nut 752, clamping ring 753, rubber circle 754, tube socket 751 fixed connection is at the connecting ball valve top, tube socket 751 top fixedly connected with butt joint round platform 7511, the screw thread is formed in butt joint round platform 751 outside, nut 752 is the pagoda joint nut, nut 752 and butt joint round platform 751 are screwed, still be provided with clamping ring 753 and rubber circle 754 between nut 752 and the butt joint round platform 7511, nut 752, clamping ring 753, rubber circle 754 center department all has seted up the through-hole with annotating liquid pipe 10 looks adaptation, be convenient for annotate liquid pipe 10 insert in tube socket 751, set up the annular hole 7521 with 753 looks adaptation in the nut 752, the recess 7531 has high diameter less than the rubber circle cross-section, after inserting the liquid pipe 10 into 751, rotatory 752 is the clamping ring 753, can drive clamping ring 754, can drive the clamping ring 754, can not make the compression ring 754, and can be pressed down the annular ring 754 is realized to the compression ring 754, and can be deformed by the deformation of rubber circle 753, and can be further deformed by the compression ring 753, can be realized, and can not be deformed by the compression ring to compression ring seal down, and can be deformed by the compression ring and can's 3.

Referring to fig. 8, the level gauge assembly 76 includes a level gauge 761, a level gauge packaging head 762, a mounting pipe 763, a connecting bellows 764, a level gauge mounting joint 765, a top transition flange 74 is fixedly connected with the level gauge mounting joint 765, wherein the mounting pipe 763 includes a first mounting pipe 7631 and a second mounting pipe 7632, the top end of the first mounting pipe 7631 is fixedly connected with the level gauge mounting joint 765, in order to prevent structural damage caused by deformation generated by low temperature cold contraction, the first mounting pipe 7631 is fixedly connected with the middle transition flange 73, the first mounting pipe 7631 is lapped with the level gauge mounting joint 765, a gap is reserved, the bottom end of the first mounting pipe 7631 is fixedly welded with the second mounting pipe 7632 through the connecting bellows 764, the bottom of the second mounting pipe 7632 is communicated with an upper hemisphere of the inner cavity, the level gauge 761 passes through the level gauge mounting joint 765, the first mounting pipe 7631, the connecting bellows 764, the second mounting pipe 7632 enters the inner cavity of the inner cavity assembly 62 and stretches into the bottom of the inner cavity, when the level gauge is measured, the level gauge is packaged, the shape is sealed between the level gauge mounting joint 763 and the top of the level gauge mounting joint 763 is further sealed by the connecting bellows 763.

Referring to fig. 9 and 10, the gauge mounting joint 765 includes a docking tube 7651, a sealing nut 7652, a pressure pad 7653, and a gauge seal 7654; the butt joint pipe 7651, the sealing nut 7652, the pressing pad 7653 and the liquid level meter sealing ring 7654 are provided with mounting holes matched with the liquid level meter 761 in the center, the butt joint pipe 7651 is fixedly connected to the top end of the flange 74 on the top and is communicated with the first closed cavity structure, threads are formed on the outer side of the butt joint pipe 7651, the sealing nut 7652 is connected in a screwed mode, a trapezoid concave hole 76511 is formed on the top of the butt joint pipe 7651, a gap is reserved between the sealing nut 7652 and the butt joint pipe 7651, the T-shaped pressing pad 7653 is matched and mounted, the liquid level meter sealing ring 7654 is located between the bottom of the pressing pad 7653 and the trapezoid concave hole 76511, the sealing nut 7652 is rotated, the sealing nut 7652 drives the liquid level meter sealing ring 7654 to deform through the pressing of the pressing pad 7653, the liquid level meter sealing ring 7654 moves towards the oblique side of the trapezoid concave hole 76511 through the arrangement of the trapezoid concave hole 76511, and side sealing of the circumference of the liquid level meter 761 is achieved;

the first installation pipe 7631 runs through the intermediate transition flange 73, and the communication hole 7633 has been seted up to the one end that first installation pipe 7631 is located between intermediate transition flange 73 and top transition flange 74 for installation pipe 763 and first cavity structure UNICOM prevent that helium from entering and producing the risk of holding down the pressure in the installation pipe 763.

Referring to fig. 2, the connecting pipeline comprises a re-heating pressurization pipeline 103, a first vacuumizing pipeline 101, a second vacuumizing pipeline 102 and a helium filling pipeline, wherein the re-heating pressurization pipeline, the first vacuumizing pipeline 101 and the helium filling pipeline are all communicated with the first closed cavity structure, the second vacuumizing pipeline 102 is communicated with the interlayer, the helium filling pipeline comprises a helium filling pipe 31, the liquid filling pipe 10 comprises a liquid helium filling pipe 11 and a liquid nitrogen filling pipe 21, and the liquid helium unit comprises a liquid helium dewar 1; the liquid nitrogen unit comprises a liquid nitrogen Dewar 2, a helium bottle 3, a liquid helium Dewar 1, a liquid helium filling pipe 21 and a first closed cavity structure, wherein the liquid nitrogen Dewar 2 is connected with a pipe seat 751 of an infusion pipe joint assembly 75 through a liquid helium filling pipe 11, the liquid nitrogen Dewar 2 is connected with the pipe seat 751 of the infusion pipe joint assembly 75 through the liquid nitrogen filling pipe 21, the helium bottle 3 is connected with the first closed cavity structure through the helium filling pipe 31, and the liquid helium Dewar 1, the liquid helium Dewar 2 and the helium bottle 3 are all commercially available parts and are provided with a pressurizing device to input a medium stored in the liquid helium Dewar 1 and the liquid helium Dewar 2 into a storage Dewar 6; the liquid helium filling pipe 11 is provided with a liquid helium ball valve, which is hereinafter denoted as V20; a liquid nitrogen ball valve is arranged on the liquid nitrogen filling pipe 21, and is hereinafter denoted as V21;

the rewarming supercharging device comprises an air bath heat exchanger 4, wherein the air bath heat exchanger 4 is communicated with a first closed cavity structure through a rewarming supercharging pipeline 103, an evacuating pump group 5 is communicated with the first closed cavity structure through a first evacuating pipeline 101, the evacuating pump group 5 is also communicated with an interlayer of a storage Dewar 6 through a second evacuating pipeline 102, a helium filling ball valve 311 is arranged on a helium filling pipe 31, and the following is denoted as V22; the helium filling pipe 31 is also connected with an exhaust pipeline 104, and the exhaust pipeline 104 is provided with an on-off ball valve 1042 (not shown) and an exhaust ball valve 1041, which are hereinafter denoted as V24 and V25; the first vacuumizing pipeline 101 is provided with a pressure sensor, a pressure gauge, a safety valve 1013, a first ball valve 1011 and a vacuum diaphragm ball valve 1012, which are hereinafter referred to as PT200, PG200, PSV200, HV222 and HV223, and the rewarming pipeline 103 is provided with a rewarming pipeline ball valve 1031, a pressure sensor 1032 and an exhaust valve 1033, which are hereinafter referred to as HV231, PT200 and HV232; the second evacuation pipeline 102 is provided with a second ball valve 1021, a vacuum gauge and a resistance gauge, which are hereinafter referred to as HV224, PT200 and PT200;

the outer diameter of the liquid injection tube 10 is smaller than the inner diameter of the inner tube 72, and when the liquid injection tube 10 is injected with liquid (liquid nitrogen or liquid helium or helium), gas enters the first closed cavity structure through a gap between the liquid injection tube 10 and the inner tube 72, and can be discharged through a control valve on the exhaust pipeline 104.

The using method comprises the following steps:

s1, evacuating, pre-cooling with liquid nitrogen, and cooling;

before the system is cooled down, all valves are closed, valve HV224 is opened, and the interlayer of the storage Dewar 6 is pumped down to be better than 0.1Pa through a pump-down pump set 5; after the evacuation is finished, the valve HV224 is closed, the liquid nitrogen filling pipe 21 is inserted into the storage dewar 6 from the top of the infusion tube joint assembly 75 of the neck tube assembly 7, the screw cap 752 is screwed down, the O-shaped rubber ring 754 is pressed by the screw cap 752, the sealing and fixing of the liquid nitrogen filling pipe 21 are realized, the valve V23 is opened, the valves HV231 and HV232 are opened, the liquid nitrogen ball valve V21 is opened, the liquid nitrogen stored in the liquid nitrogen dewar 2 is conveyed into the storage dewar 6, the storage dewar 6 is pre-cooled, and compared with the direct use of liquid helium for cooling, the cost is greatly reduced; in order to prevent liquid nitrogen from accumulating in the storage dewar 6, when the temperature of the inner cavity of the storage dewar 6 is lower than 100K, the nut 752 is reversely screwed, the sealing and fixing of the O-shaped rubber ring 754 on the liquid nitrogen filling pipe 21 are released, the liquid nitrogen filling pipe 21 is pulled out, and the valve V23 is closed;

s2, evacuating and replacing;

after the liquid nitrogen is precooled and cooled, if liquid nitrogen effusion exists in the inner cavity of the storage Dewar 6, opening a ball valve V22, pressurizing the inner cavity of the storage Dewar 6, and discharging residual liquid nitrogen into the air through a valve V25; after discharging the liquid nitrogen, evacuating and replacing the storage Dewar 6 and related pipelines: sequentially closing the valves HV224, V22 and HV232, and sequentially opening the valves HV222, HV223 and HV231; then opening the pump-out pump set 5, closing the HV223 and the pump-out pump set 5 when the pressure is lower than 1mbar, opening the valve V-22 and the pressure reducing valve DPV221, and introducing high-purity helium gas into the storage Dewar 6 to micro positive pressure; this process is performed at least twice;

s3, adding helium and rewarming;

filling liquid helium into the storage Dewar 6 after the evacuation replacement is finished, and performing a pressurization test of the storage Dewar 6 after the liquid helium is filled; after the test is finished, the low-temperature helium is heated to more than 200K by a rewarming device.

Closing a valve V22 after the evacuation replacement is finished, opening a liquid helium ball valve V20 and an exhaust valve HV232, controlling the liquid helium infusion rate and the pressure in a storage Dewar 6 through the opening and closing of the valve V20 and the valve HV232, maintaining the pressure within the range of 1.1-1.2 bara, and monitoring the storage amount of liquid helium in the storage Dewar 6 through an electronic platform scale 8 in the liquid injection process;

after the injection of liquid helium into the storage dewar 6 is completed, the liquid helium injection valve V20 is closed, the liquid helium injection tube 11 is pulled out, and the valves V23, HV231, HV222, HV223 are closed. Starting a pressurization test of the stored Dewar 6; after the test is finished, the valves HV231 and HV232 are opened, the opening sizes of the two valves are adjusted, and the low-temperature helium is heated to more than 200K through the air bath heat exchanger 4.

The above embodiments are only for illustrating the technical solution of the present utility model, and are not limiting; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model.

Claims (8)

1. The utility model provides a level gauge mounting structure, its characterized in that, includes neck pipe assembly, level gauge assembly, neck pipe assembly axial is equipped with first airtight cavity structure and the airtight cavity structure of second in proper order, the neck pipe assembly top is located to the level gauge assembly is fixed, the level gauge assembly is including the mounting tube that runs through first airtight cavity structure and the airtight cavity structure of second, the connecting hole that is linked together with first airtight cavity structure has been seted up to the one section that the mounting tube is located first airtight cavity structure, the mounting tube passes through connecting hole, the airtight cavity structure of first and outside exhaust line intercommunication.

2. The liquid level meter mounting structure according to claim 1, wherein the neck tube assembly comprises an outer tube, an inner tube, an intermediate transition flange and a top transition flange, the outer tube is fixedly connected to the top of the flange, the inner tube is fixedly arranged in the outer tube through the intermediate transition flange, the top transition flange is fixedly connected to the top of the outer tube, the top transition flange, the inner wall of the outer tube and the intermediate transition flange enclose to form a first closed cavity structure, and the intermediate transition flange, the inner wall of the outer tube and the outer wall of the inner tube form a second closed cavity structure.

3. The liquid level gauge mounting structure of claim 2, wherein the liquid level gauge assembly comprises a liquid level gauge mounting joint, wherein the liquid level gauge mounting joint is fixedly connected to the top transition flange and is used for side sealing and fixing the liquid level gauge.

4. A gauge mounting structure according to claim 3, wherein the gauge assembly further comprises a connecting bellows, the mounting tube comprises a first mounting tube and a second mounting tube, the top end of the first mounting tube is fixedly connected to the gauge mounting joint, and the first mounting tube is fixedly connected to the second mounting tube through the connecting bellows.

5. The liquid level meter mounting structure according to claim 4, wherein the liquid level meter mounting joint comprises a butt joint pipe, a sealing nut, a pressing pad and a liquid level meter sealing ring, mounting holes matched with the liquid level meter are formed in the centers of the butt joint pipe, the sealing nut, the pressing pad and the liquid level meter sealing ring, the sealing nut is connected with the butt joint pipe in a screwed mode, and the pressing pad and the liquid level meter sealing ring are further arranged between the sealing nut and the butt joint pipe.

6. The fluid level gauge mounting structure of claim 5, wherein the top of the docking tube is formed with a trapezoidal recess.

7. The liquid level gauge mounting structure of claim 2, wherein the top transition flange top is fixedly connected with a liquid injection joint.

8. The fluid level gauge mounting structure of claim 5, further comprising a fluid level gauge package head and a fluid level gauge gasket, the fluid level gauge package head being rotatably coupled to the docking tube, the fluid level gauge gasket being positioned between the fluid level gauge package head and the docking tube.