CN201141487Y

CN201141487Y - Flange joint structure of multi-layer vacuum heat-insulation pipe with low heat leakage

Info

Publication number: CN201141487Y
Application number: CNU200720186323XU
Authority: CN
Inventors: 韩战秀; 王森; 刘玉涛; 瞿骞; 孙万民
Original assignee: Beijing Institute of Aerospace Testing Technology
Current assignee: Beijing Institute of Aerospace Testing Technology
Priority date: 2007-12-26
Filing date: 2007-12-26
Publication date: 2008-10-29
Anticipated expiration: 2017-12-26

Abstract

The utility model relates to a connecting structure of the thermal insulated tube, in particular to a flange connecting structure of the multi-layer vacuum thermal insulated tube with low thermal leakage rate. The flange connecting structure comprises an outer convex shoulder ring welded with a left side outer tube connector, an outer concave shoulder ring welded with a right side outer tube connector, an outer shim arranged between the outer convex shoulder ring and the outer concave shoulder ring and a flange and a bolt used for clamping the outer convex shoulder ring and the outer concave shoulder ring; two U-shaped heat bridges are arranged between the inner tube and outer tube adjacent to the left side connector and right side connector, one end of the two heat bridges are respectively welded with the outer convex shoulder ring and the outer concave shoulder ring, and the other ends of the two heat bridges are welded with the inner tube; a through hole communicated with the inside and the outside of the outer concave shoulder ring is drilled on the outer concave shoulder ring, and an evacuation nipple is installed on the through hole; an inner concave shoulder ring and an inner convex shoulder ring are arranged at the inner tube connector, and an inner shim is arranged between the inner concave shoulder ring and the inner convex shoulder ring. The flange connecting structure has the advantages that the sealing performance is good, the thermal leakage rate is low, the service life is long, and the disassembly and the assembly are convenient.

Description

A kind of flanged connecting structure of vacuum multilayer insulation pipe of low thermal leakage ratio

Technical field

The utility model belongs to the linkage structure of heat-insulated pipe, is specifically related to a kind of linkage structure of vacuum multilayer insulation pipe.

Background technique

Along with the cryogen medium (as liquid nitrogen, liquid oxygen, liquid hydrogen, liquid helium etc.) in the extensive use of national defence, chemical industry, space flight and other frontiers of science and technology, and the heat transfer that how to reduce pipeline internal medium and external environment during fed sheet of a media is one of critical technical problems, guarantee that what adopt is the vacuum multilayer insulation form to good insulation effect delivery pipe is more.The vacuum multilayer insulation pipe connecting structure adopts usually both at home and abroad: spigot and socket type, vacuum flange, three kinds of structural types of welded structure.Welded structure is leaked hot little, but mounting or dismounting are inconvenient; Spigot and socket type is installed and removed convenient but is needed bigger space; It is convenient that vacuum flange connects mounting or dismounting, is traditional pipeline Connecting format, but existing vacuum flange structure thermal leakage ratio in above-mentioned three kinds of Connecting format is bigger.In the utility application of the portion " a kind of flanged connecting structure of vacuum multilayer insulation pipe " by name that the applicant submits to the same period, a kind of two-layer sealing has been proposed, the centre has the flanged connecting structure of the vacuum heat-insulating pipe of collet, it is convenient that this linkage structure has the installation and removal of vacuum pipeline section, and can realize reliable sealing and adiabatic having a few, but in particular cases can go wrong at some, as: poorly sealed 1), external sealed is good, then cryogenic media bleeds in the heat bridge, because the flange of normal temperature links to each other with heat bridge, cryogenic media contacts with flange and makes the flange surface temperature reduce the serious frosting of appearance; 2) interior good seal, external sealed is not tight, and gas at normal temperature enters in the heat bridge, interior pipe heat exchange occurs with ambient atmos, pipe temperature rising in making, and then the cryogenic media temperature raises in causing managing, gasification occurs, occur liquid, gas two phase flow in the pipe, reduce the cryogenic media quality; 3) inside and outside sealing is all not tight, and then not only flange is understood serious frosting, and leakage occurs at flange connections.So vacuum pipe needs to carry out machining after welding fully, be air between the vacuum flange inner and outer pipes, during the transporting cryogenic medium, the fixed gas between the inside and outside pipeline will increase the heat conduction of vacuum flange.

Summary of the invention

The purpose of this utility model is to provide a kind of flanged connecting structure that seals the vacuum multilayer insulation pipe of effectively low thermal leakage ratio.

The technical solution of the utility model is as follows:

A kind of flanged connecting structure of vacuum multilayer insulation pipe of low thermal leakage ratio, comprise outer convex shoulder circle with the welding of left side outer tube joint, with the outer recessed shoulder circle of right side outer tube joint welding, be located at the outer pad between outer convex shoulder circle, the outer recessed shoulder circle and be used to clamp the flange of outer convex shoulder circle, outer recessed shoulder circle and bolt, nut; Be respectively equipped with the U-shaped heat bridge between the outer tube on the right side of the left side of convex shoulder circle and outer recessed shoulder circle and the interior pipe outside, two heat bridge one ends weld with outer recessed shoulder circle, outer convex shoulder circle respectively, the other end and the welding of interior pipe, it is characterized in that: be drilled with the through hole inside and outside the recessed shoulder circle outside being communicated with on the outer recessed shoulder circle, be equipped with on the through hole and find time to connect mouth; The internal shoulder circle that the inner pipe joint place also is provided with indent shoulder circle and matches with it is provided with internal gasket between indent shoulder circle and internal shoulder circle.

Described indent shoulder circle and internal shoulder circle and internal gasket surface of contact are provided with the sealing convex line.

Described internal gasket material is a red copper, and outer gasket material is a vacuum rubber.

Advantage of the present utility model is: 1, since inside and outside shoulder circle between the flange chamber find time after, charge into carbon dioxide, reduced non-condensible gas heat conduction, reduced the thermal leakage ratio of this linkage structure; 2, indent shoulder circle and internal shoulder circle and internal gasket surface of contact are provided with the sealing convex line, waterline sealing surface form is carved on original plane, change the plane into and reserve the form of sealing convex line, the problem that the heat bridge that has overcome that the vacuum flange pretightening force causes more greatly reduces working life; 3, the internal gasket material is a red copper, and outer gasket material is a vacuum rubber, in be sealed into hard sealing, external sealed is soft seal, has overcome in the existing vacuum flange to be sealed into soft seal, every the problem of not trapping of liquid, has further reduced thermal leakage ratio; In addition, in the utility model, indent shoulder circle and internal shoulder circle and interior pipe do not weld, and disassembly and assembly are convenient.

Description of drawings

Fig. 1 is the schematic representation of flanged connecting structure of the vacuum multilayer insulation pipe of a kind of low thermal leakage ratio of providing of the utility model;

Fig. 2 is the enlarged diagram at A place among Fig. 1.

Among the figure, 1, interior pipe; 2, heat bridge; 3, outer recessed shoulder circle; 4, flange; 5, find time to connect mouth; 6, outer pad; 7, internal shoulder circle; 8, indent shoulder circle; 9, internal gasket; 10, outer tube; 11, bolt; 12, outer convex shoulder circle; 13, pad; 14, nut; 15, sealing convex line

Embodiment

Below in conjunction with the drawings and specific embodiments the utility model is done detailed description further.

As shown in Figure 1, a kind of flanged connecting structure of vacuum multilayer insulation pipe of low thermal leakage ratio, comprise outer convex shoulder circle 12 with the welding of left side outer tube 10 joints, with the outer recessed shoulder circle 3 of right side outer tube 10 joints welding, be located at the outer pad 6 of the vacuum rubber system between outer convex shoulder circle 12, the outer recessed shoulder circle 3 and be used to clamp the flange 4 and the bolt 11 of outer convex shoulder circle 12, outer recessed shoulder circle 3; An end that is respectively equipped with 2, two heat bridges 2 of U-shaped heat bridge outside outside the left side of convex shoulder circle 12 between the outer tube 10 on the right side of recessed shoulder circle 3 and the interior pipe 1 welds the other end and 1 welding of interior pipe with outer convex shoulder circle 12, outer recessed shoulder circle 3 respectively; Be drilled with the through hole inside and outside the recessed shoulder circle 3 outside being communicated with on the outer recessed shoulder circle 3, be equipped with on the through hole and find time to connect mouth 5; In the pipe 1 joint internal shoulder circle 7 that also is provided with indent shoulder circle 8 and matches with it, indent shoulder circle 8 and 7 on internal shoulder circle are provided with purple internal gasket made of copper 9; On indent shoulder circle 8 and internal shoulder circle 7 and internal gasket 9 surface of contact, be provided with sealing convex line 15.

After the flange 4 linkage structures assembling of the vacuum multilayer insulation pipe of above-mentioned low thermal leakage ratio, welding were finished, this structure of pretension did not match if find inside and outside closure size, turn on flange 4 bolts 11, internal shoulder circle 7 or indent shoulder circle 8 are taken off, process, mate up to size; Behind the structure pretension, carry out the inspection of normal temperature sealability, seal operation performance in observing by the connecting-tube nozzle of finding time is if blow-by is reinstalled.Behind the interior sealing installation in position, carry out the low temperature seal performance checking, the sealing state of sealing if leakage increases pretightening force, meets the sealability inspection up to interior sealing in observing by the connecting-tube nozzle of finding time; After interior sealability checks out, Seal cage is found time moving vacuum pressure 1.33 * 10 by the connecting-tube nozzle of finding time ^-3Pa, the carbon dioxide that refills purity 99.999% are to 1000Pa, and sealing finds time to connect mouth 5.

Working principle of the present utility model is: when cryogenic media is flowed through this linkage structure, in pipe 1 be cooled to medium temperature, the carbon dioxide condensing frosting in the flange enclosed cavity has further improved the degree of vacuum of flange enclosed cavity, metallic material discharges the gas of trace, is mainly H ₂, H ₂Reach other non-condensible gases and coagulate white capture, further reduced the degree of vacuum of enclosed cavity, reduced the gas conduction rate of this structure, therefore improving insulation effect greatly via carbon dioxide.

Claims

1. the flanged connecting structure of the vacuum multilayer insulation pipe of a low thermal leakage ratio, comprise outer convex shoulder circle (12) with the welding of left side outer tube (10) joint, with the outer recessed shoulder circle (3) of right side outer tube (10) joint welding, be located at the outer pad (6) between outer convex shoulder circle (12), the outer recessed shoulder circle (3) and be used to clamp the flange (4) of outer convex shoulder circle (12), outer recessed shoulder circle (3) and bolt (11), nut (14); Be respectively equipped with U-shaped heat bridge (2) between the outer tube (10) on the right side of the left side of convex shoulder circle (12) and outer recessed shoulder circle (3) and the interior pipe (1) outside, two heat bridge (2) one ends weld with outer recessed shoulder circle (3), outer convex shoulder circle (12) respectively, the other end and interior pipe (1) welding, it is characterized in that: be drilled with the through hole inside and outside the recessed shoulder circle (3) outside being communicated with on the outer recessed shoulder circle (3), be equipped with on the through hole and find time to connect mouth (5); The internal shoulder circle (7) that interior pipe (1) joint also is provided with indent shoulder circle (8) and matches with it, the indent shoulder encloses between (8) and internal shoulder circle (7) and is provided with internal gasket (9).

2. the flanged connecting structure of the vacuum multilayer insulation pipe of a kind of low thermal leakage ratio as claimed in claim 1 is characterized in that: described indent shoulder circle (8) and internal shoulder circle (7) and internal gasket (9) surface of contact are provided with the sealing convex line.

3. the flanged connecting structure of the vacuum multilayer insulation pipe of a kind of low thermal leakage ratio as claimed in claim 1 or 2, it is characterized in that: described internal gasket (9) material is a red copper, outer pad (6) material is a vacuum rubber.