CN212178517U - Liquid helium container - Google Patents
Liquid helium container Download PDFInfo
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- CN212178517U CN212178517U CN202020606443.6U CN202020606443U CN212178517U CN 212178517 U CN212178517 U CN 212178517U CN 202020606443 U CN202020606443 U CN 202020606443U CN 212178517 U CN212178517 U CN 212178517U
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Abstract
The utility model discloses a liquid helium container, including shell and the inner bag of installation in the shell, from interior to exterior has set gradually high vacuum layer between shell and the inner bag, many screen heat insulation layers and multilayer heat insulation layer, still be provided with the high temperature getter between shell and the multilayer heat insulation layer, still be provided with the low temperature getter in the high vacuum layer, heat insulation layer and multilayer heat insulation layer reduce the radiation heat transfer through adopting many screen, and retrieve the sensible heat of helium and reduce the heat leakage, keep the inner bag outer and many screen heat insulation layer's high vacuum degree, reduce thermal contact resistance, solid heat conduction and gaseous heat conduction, make liquid helium container obtain high thermal insulation performance.
Description
Technical Field
The utility model belongs to the technical field of liquid helium storage technique and specifically relates to a liquid helium container.
Background
Helium is widely used in the industrial field, plays an irreplaceable role in the fields of aerospace, national defense, low-temperature physics, gas phase analysis, welding, leakage detection, chemical vapor deposition, crystal growth, plasma dry etching, particle accelerators, low-temperature superconduction, nuclear magnetic resonance imaging and the like, and most of helium relates to storage and transportation of liquid helium. However, liquid helium is a liquefied gas which has a very low boiling point, a very low latent heat of vaporization, is very easy to vaporize and is very difficult to store, and therefore, the liquid helium container has a very high requirement on the heat insulation performance.
The conventional insulation methods used in cryogenic containers in the liquid helium temperature range include three types, namely multilayer insulation, multi-panel insulation and multilayer-vapor-cooled panel insulation, which can meet the general requirements of liquid helium storage, but still have some disadvantages. The multilayer heat insulation structure is generally directly wrapped on the liner, so that solid heat conduction exists between the multilayer heat insulation structure and the liner, the multilayer heat insulation structure is tightly wound, the difficulty of vacuumizing the interior of the multilayer heat insulator is high, and the heat conduction of gas in the multilayer heat insulator is high; the number of the single multi-screen heat insulation screens is lower than that of the multi-layer heat insulation screens, the number of the radiation screens is small, and the effect of blocking radiation heat transfer is still a space for further improving; the efficiency of the multi-layer steam cooling screen is not high, the efficiency of the multi-layer steam cooling screen is generally lower than that of the high-vacuum steam cooling screen, and the screen temperature is also higher than that of the high-vacuum steam cooling screen. Meanwhile, as the radiation heat leakage is greatly reduced at low temperature, and a plurality of layers of materials are wound in a plurality of layers of heat insulation spaces in the multi-layer heat insulator, the solid heat conduction is increased, in addition, the air suction is difficult, the heat transfer of residual gas is also increased, the longitudinal heat conduction is also difficult to avoid, and the total heat leakage quantity is also correspondingly increased.
Those skilled in the art have therefore endeavored to develop a liquid helium vessel with extremely high thermal insulation properties.
Disclosure of Invention
In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a liquid helium vessel with extremely high thermal insulation performance.
In order to realize the above object, the utility model provides a liquid helium container, include the shell and install inner bag in the shell, the upper end of inner bag is provided with the neck pipe that upwards extends and communicate with the external world, from interior to exterior has set gradually high vacuum layer, heat insulation layer and multilayer heat insulation layer of shielding between shell and the inner bag.
Many screen heat insulation layers include two at least conduction screens of range upon range of setting, the one end of conduction screen through one with neck pipe welded connection's I shape fin fixed connection.
A first spacing layer is arranged between two adjacent conduction screens, and the two adjacent conduction screens are arranged in a vacuumizing mode.
The material of the conducting screen is aluminum or copper.
The conductive screen is provided with 10-35 layers, and preferably, the conductive screen is provided with 12-20 layers.
The multilayer heat insulation layer comprises at least two layers of radiation screens which are stacked, and a second partition layer is arranged between every two adjacent radiation screens.
The radiation screen is provided with 5-25 layers, preferably 20-25 layers.
And a low-temperature getter is also arranged in the high vacuum layer.
And a high-temperature getter is also arranged between the shell and the multilayer heat insulating layer.
The distance l between two adjacent conductive screens on the neck is obtained by the following formula:
in the formula: m is the evaporation rate of the liquid helium container, n is the number of layers of the conductive screen, and LbLatent heat of vaporization of liquid helium, AiI is an area of the ith screen, i is 2 or more, σ is a radiation constant,ithe radiance between the ith conducting screen and the (i-1) th conducting screen, s is the cross-sectional area of the neck, L is the distance between two adjacent conducting screens on the neck, H0Is the enthalpy of saturated helium vapor, Ki、λi、HiThe thermal conductivity of the conductive screen, the thermal conductivity of the neck tube and the enthalpy of the helium vapor, T, respectively, varying with temperatureiIs the temperature of the surface of the individual conductive screens.
The utility model has the advantages that: the utility model discloses a liquid helium container, inner bag in shell including shell and installation, from interior to exterior has set gradually high vacuum layer between shell and the inner bag, many screen heat insulation layer and multilayer heat insulation layer, still be provided with the high temperature getter between shell and the multilayer heat insulation layer, still be provided with the low temperature getter in the high vacuum layer, reduce the radiation heat transfer through adopting many screen heat insulation layer and multilayer heat insulation layer, and retrieve the sensible heat of helium and reduce the heat leakage, keep the inner bag outside and many screen heat insulation layer's high vacuum, reduce thermal contact resistance, solid heat conduction and gaseous heat conduction, make liquid helium container obtain high thermal insulation performance.
Drawings
FIG. 1 is a schematic sectional view of the structure of the present invention;
fig. 2 is a schematic diagram of a heat transfer model of a multi-screen heat insulating layer according to the present invention.
Detailed Description
The present invention will be further described with reference to the accompanying drawings and examples, wherein it is noted that, in the description of the invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular manner, and therefore should not be construed as limiting the present invention. The terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
As shown in fig. 1 and 2, the liquid helium container comprises a shell 1 and an inner container 2 installed in the shell 1, wherein a neck pipe 11 which extends upwards and is communicated with the outside is arranged at the upper end of the inner container 2, and a high vacuum layer 3, a multi-screen heat insulation layer and a multi-layer heat insulation layer are sequentially arranged between the shell 1 and the inner container 2 from inside to outside. A high-temperature getter is further arranged between the shell and the multiple heat insulation layers, a low-temperature getter is further arranged in the high-vacuum layer, radiation heat transfer is reduced by adopting the multiple heat insulation layers and the multiple heat insulation layers, sensible heat of helium is recovered, heat leakage is reduced, high vacuum degrees outside the inner container and the multiple heat insulation layers are maintained, contact thermal resistance is reduced, solid heat conduction and gas heat conduction are achieved, and the liquid helium container is enabled to obtain extremely high heat insulation performance.
The multi-screen heat insulation layer comprises at least two laminated conduction screens 4, one ends of the conduction screens 4 are fixedly connected through an I-shaped fin 8 welded with the neck pipe 11, the conduction screens 4 are tightly connected with the I-shaped fin 8, the thermal resistance is reduced, and the cold energy is recovered; a first spacing layer 5 is arranged between two adjacent conductive screens 4, and a vacuum is pumped between the two adjacent conductive screens 4. The first spacing layer 5 is in contact connection with the conduction screen 4, and a certain gap exists between the first spacing layer and the conduction screen 4, so that the vacuum pumping is easy, the high interlayer vacuum degree can be achieved after the vacuum pumping, the solid heat conduction, the longitudinal heat conduction and the residual gas heat conduction are effectively reduced, and the heat insulation performance is greatly improved. In this embodiment the material of the conductive screen 4 is aluminium or copper and the conductive screen 4 is provided with 10-35 layers, preferably 12-20 layers.
The design of the conductive screen 4 can be made in different ways, and the following algorithm is recommended. And (3) ignoring the change of the thermal conductivity coefficient along with the temperature, and not considering the contact thermal resistance between the conduction screen and the neck tube, the air film thermal resistance in the neck tube and the temperature gradient on the conduction screen, and carrying out heat transfer analysis on the multi-screen heat insulation under the ideal condition. A multi-panel adiabatic heat transfer model is shown in fig. 2. After n conductive screens are arranged on the neck, the radiant heat q on the nth screenr(n) is divided into two parts: a part qr(n-1) is transmitted into the (n-1) th screen, and another part q is transmitted into the (n-1) th screenm(n) passing along the screen to the neck; similarly, heat flow q from the hot end of the neck to the nth screenk(n) is also divided into two parts: a part qk(n-1) leading into the (n-1) th screen; another part qk(n) and qm(n) are carried away together by the cold vapor.
There is therefore the following equation for heat transfer.
From this, the temperature T on the i-th block conductive screen can be obtainediThe calculation formula of (2) is as follows:
and from the above equation, the relationship for the evaporation rate m can be found as follows:
in the above formula: l isbLatent heat of vaporization of liquid helium, AiIs the area of the ith screen, s is the cross-sectional area of the neck, is the screen spacing, l is the spacing of two adjacent conductive screens 4 on the neck 11, H0Is the enthalpy of saturated helium vapor, Ki、λi、HiThe thermal conductivity of the conduction screen 4, the thermal conductivity of the neck tube 11 and the enthalpy of the helium vapor, which change with the temperature, respectively, sigma is a radiation constant,iis the emissivity, T, between the ith conductive screen and the (i-1) th conductive screeniIs the temperature of the surface of the single conductive screen 4.
For multi-panel insulation under high vacuum conditions, because residual gas thermal conduction and longitudinal thermal conduction are substantially negligible:
therefore, the distance l between two adjacent conductive screens 4 on the neck 11 is given by reference to the following equation:
in the formula: m is the evaporation rate of the liquid helium vessel, n is the number of layers of the conductive screen 4, LbLatent heat of vaporization of liquid helium, AiI is the area of the ith screen, i is greater than or equal to2, sigma is the radiation constant,iis the emissivity between the ith conductive screen 4 and the (i-1) th conductive screen 4, s is the cross-sectional area of the neck, l is the distance between two adjacent conductive screens 4 on the neck 11, H0Is the enthalpy of saturated helium vapor, Ki、λi、HiThe thermal conductivity of the conductive screen 4, the thermal conductivity of the neck 11 and the enthalpy of the helium vapor, T, respectively, varying with the temperatureiIs the temperature of the surface of the single conductive screen 4.
And about 20 additional layers of multi-layer heat insulation layers are additionally arranged between the multi-screen heat insulation layers and the shell 1, so that the radiation heat transfer is further reduced, and the heat insulation performance is improved. The multilayer heat insulation layer comprises at least two layers of radiation screens 6 which are arranged in a stacked mode, and a second partition layer 7 is arranged between every two adjacent layers of radiation screens 6, wherein the radiation screens 6 are generally aluminum foils or copper foils; the radiation screen 6 is separated from the neck pipe 11, namely is not connected with the neck pipe 11, so that the heat insulation performance is effectively improved; wherein the radiation screen 6 is provided with 5-25 layers, preferably the radiation screen 6 is provided with 20-25 layers. Since the main function of the conduction screen 4 is to transmit the recovered cold and the main function of the radiation screen 6 is to reflect the heat, the thickness of the conduction screen 4 is greater than that of the radiation screen 6.
In this embodiment, the first spacing layer 5 and the second spacing layer 7 are both materials with good thermal insulation performance, such as fiberglass paper and nylon net.
Above-mentioned radiation screen 6 and conduction screen 4 set up quantity all be utility model people have considered the position relation, material strength, adiabatic effect, I shape fin and the contact degree and the processing technology complexity of conduction screen 4 of each part in the container comprehensively, then through the many times experimental reachs. The utility model discloses the people think of specially emphasising, can see from above that utility model people is solving the technical problem process that the utility model discloses will solve, has paid very big creative work, and does not have ready-made data to refer to moreover, and this is also difficult for the technical staff in the liquid helium storage technical field to think of.
Because the vacuum in the heat insulation space can descend along with time, in order to keep high vacuum degree for a long time, avoid the thermal insulation performance to descend, the utility model discloses still adopted the efficient combination getter, still be provided with low temperature getter 9 in the high vacuum layer 3, still be provided with high temperature getter 10 between shell 1 and the multilayer heat insulation layer, further, low temperature getter 9 is the combination of one or more in zirco-Fe manganese getter, zirco-zircoal 16 getter and zirco-vanadic getter, and high temperature getter 10 is the combination of one or more in zirco-Al 16 getter, zirco-graphite getter, zirconi getter and zirco-vanadic getter. By adopting the efficient combination of the getters, the heat-insulating space can maintain an ideal vacuum degree for a long time, so that the liquid helium container can also maintain extremely high heat-insulating performance for a long time.
The utility model discloses a high-efficient compound adiabatic tries to overcome the weak point of above-mentioned adiabatic structure, has effectively blocked each item way that heat spreads into cryogenic liquids in the container into, therefore can obtain high adiabatic performance. The utility model discloses an adiabatic structure be high vacuum layer, many screen heat insulation layers and multilayer heat insulation layer from the inner bag to the shell in proper order. The high vacuum layer is arranged outside the inner container, so that the vacuum degree and the efficiency of the conduction screen can be effectively improved, and the heat insulation performance is improved. And the middle part adopts multi-screen heat insulation, so that the sensible heat after helium vaporization is effectively recovered, the screen temperature is reduced, and the heat insulation performance is greatly improved. The multi-screen heat insulation layer consists of 20 layers of left and right conduction screens and a first spacing layer between the screens, the conduction screens are in loose contact with each other and are pumped to a high vacuum degree, and each conduction screen is tightly attached to the neck pipe through an I-shaped fin, so that heat leakage can be effectively reduced, and the heat insulation performance is further improved. And about 20 layers of multi-layer heat insulation layers are additionally arranged between the multi-screen heat insulation layers and the shell, so that the radiation heat transfer is further reduced, and the heat insulation performance is improved.
The utility model has the advantages that:
(1) low-temperature gases such as helium and hydrogen have a large sensible heat/latent heat ratio because they have a small latent heat. That is, only a small amount of heat is required to vaporize. Meanwhile, the difference between the saturation temperature and the ambient temperature is very large, so the cold stored in the sensible heat form of the gasified saturated low-temperature gas is very large. Conventional cryogenic storage vessels can only utilize the latent heat of liquefied gases. The composite heat insulation structure of the utility model adopts multi-screen heat insulation, can fully utilize the sensible heat of liquefied gas, reduce the screen temperature, inhibit the radiant heat flow, reduce the heat leakage and obviously improve the heat insulation performance;
(2) the utility model discloses set up a high vacuum space between many screen heat insulation layers and inner bag specially, reduced the heat transfer between isolator and the inner bag. In a traditional heat insulation structure, a multilayer heat insulator is often directly wrapped outside an inner container, so that solid heat conduction exists, the multilayer heat insulator is difficult to pump to a high vacuum degree, and gas heat transfer is also large. The utility model discloses set up a high vacuum layer outside the inner bag specially, can effectual solution above-mentioned problem, improve the thermal insulation performance of liquid helium container.
(3) Because the number of the heat insulating layers of multiple screens is not large (about 20 screens), although the first spacing layers exist between the screens, the screens are not tightly attached to each other, so that the vacuum pumping is easy, the high interlayer vacuum degree can be achieved, the solid heat conduction, the longitudinal heat conduction and the residual gas heat conduction are effectively reduced, and the heat insulating performance is greatly improved.
(4) Because the existence in high vacuum space and the improvement of many heat insulating layer internal vacuum degree of shielding, the utility model discloses well efficiency of conduction screen will be higher than the efficiency of conduction screen in the heat insulating structure of multilayer-vapour cold screen, and the screen temperature also is less than the screen temperature in the heat insulating structure of multilayer-vapour cold screen, therefore can obtain the thermal insulation performance than multilayer-vapour cold screen heat insulating structure is more excellent.
(5) By optimizing the screen positions in the multi-screen heat insulating layer, the full utilization of the cold energy of the low-temperature helium vapor is realized, the temperature of the conduction screen is reduced, the heat leakage is reduced, and the heat insulating performance is improved.
(6) And about 20 additional layers of multi-layer heat insulation layers are additionally arranged between the multi-screen heat insulation layers and the shell, so that the radiation heat transfer is further reduced, and the heat insulation performance is improved.
The foregoing has described in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions that can be obtained by a person skilled in the art through logic analysis, reasoning or limited experiments based on the prior art according to the concepts of the present invention should be within the scope of protection defined by the claims.
Claims (10)
1. The utility model provides a liquid helium container, includes shell (1) and installs inner bag (2) in shell (1), the upper end of inner bag (2) is provided with upwards extends and with external intercommunication neck pipe (11), characterized by: high vacuum layer (3), many screen heat insulation layer and multilayer heat insulation layer have set gradually between shell (1) and inner bag (2) from interior to exterior.
2. The liquid helium vessel of claim 1, wherein: many screen heat insulation layer include two at least conduction screens (4) of range upon range of setting, the one end of conduction screen (4) through one with neck pipe (11) welded connection's I shape fin (8) fixed connection.
3. The liquid helium vessel of claim 2, wherein: a first spacing layer (5) is arranged between two adjacent conductive screens (4), and the two adjacent conductive screens (4) are arranged in a vacuum-pumping mode.
4. A liquid helium vessel as claimed in claim 3, wherein: the material of the conductive screen (4) is aluminum or copper.
5. A liquid helium vessel as claimed in claim 3, wherein: the conductive screen (4) is provided with 10-35 layers.
6. The liquid helium vessel of claim 2, wherein: the multilayer heat insulation layer comprises at least two layers of radiation screens (6) which are stacked, and a second partition layer (7) is arranged between every two adjacent layers of radiation screens (6).
7. The liquid helium vessel of claim 6, wherein: the radiation screen (6) is provided with 5-25 layers.
8. The liquid helium vessel of claim 2, wherein: and a low-temperature getter (9) is also arranged in the high-vacuum layer (3).
9. The liquid helium vessel of claim 2, wherein: and a high-temperature getter (10) is also arranged between the shell (1) and the multilayer heat insulating layer.
10. The liquid helium vessel of any of claims 2-9, wherein: the distance l between two adjacent conductive screens (4) on the neck (11) is given by the following formula:
in the formula: m is the evaporation rate of the liquid helium container, n is the number of layers of the conductive screen (4), LbLatent heat of vaporization of liquid helium, AiI is an area of the ith screen, i is 2 or more, σ is a radiation constant,iis the emissivity between the ith said conductive screen (4) and the (i-1) th said conductive screen (4), s is the cross-sectional area of the neck, H0Is the enthalpy of saturated helium vapor, Ki、λi、HiThe thermal conductivity of the conductive screen (4), the thermal conductivity of the neck (11) and the enthalpy of the helium vapor, T, respectively, varying with the temperatureiIs the temperature of the surface of the single conductive screen (4).
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020606443.6U CN212178517U (en) | 2020-04-21 | 2020-04-21 | Liquid helium container |
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| CN202020606443.6U CN212178517U (en) | 2020-04-21 | 2020-04-21 | Liquid helium container |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111396741A (en) * | 2020-04-21 | 2020-07-10 | 重庆贝纳吉超低温应用技术研究院有限公司 | Liquid helium container |
| CN114684506A (en) * | 2020-12-29 | 2022-07-01 | 北京航天试验技术研究所 | Horizontal container for storing cryogenic liquid |
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2020
- 2020-04-21 CN CN202020606443.6U patent/CN212178517U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111396741A (en) * | 2020-04-21 | 2020-07-10 | 重庆贝纳吉超低温应用技术研究院有限公司 | Liquid helium container |
| CN111396741B (en) * | 2020-04-21 | 2024-08-06 | 重庆贝纳吉超低温应用技术研究院有限公司 | Liquid helium container |
| CN114684506A (en) * | 2020-12-29 | 2022-07-01 | 北京航天试验技术研究所 | Horizontal container for storing cryogenic liquid |
| CN114684506B (en) * | 2020-12-29 | 2024-05-28 | 北京航天试验技术研究所 | Horizontal container for storing low-temperature liquid |
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Effective date of registration: 20220711 Address after: 641300 No. 1, Xingye West Road, Zheyue energy saving industrial park, Yanjiang District, Ziyang City, Sichuan Province Patentee after: Sichuan benaji liquid nitrogen biological container Co.,Ltd. Address before: Unit 1-1, unit 2, building 2, No. 53, Gangcheng West Road, Jiangbei District, Chongqing Patentee before: Chongqing benaji Ultra Low Temperature Application Technology Research Institute Co.,Ltd. |