CN219530547U - High-capacity zero-evaporation storage liquid helium tank box - Google Patents

Abstract

The utility model relates to the technical field of low-temperature tank boxes/tank containers, in particular to a high-capacity zero-evaporation storage liquid helium tank box/tank container, which comprises: the liquid helium tank inner container, the liquid helium tank inner container cold screen coil pipe, the liquid helium liquid inlet and outlet pipe, the composite multilayer heat insulation material, the inner copper screen, the flash evaporation gas transmission pipe, the heat insulation support, the outer copper screen, the liquid helium tank outer container, the liquid helium tank steel frame, the liquid helium liquid inlet and outlet transmission pipeline, the cooling medium inner container cold screen coil pipe, the composite multilayer heat insulation material II, the inner copper screen II, the heat insulation support II, the outer copper screen II, the cryogenic cold head, the cryogenic refrigerator and the unidirectional liquid adding control valve. The utility model can cope with the situation that the internal pressure of the low-temperature tank is rapidly increased in the process of storing liquid helium under pressure for a long time and transporting liquid helium for a long time and remotely, and realizes long-term zero-evaporation storage.

Description

A large-capacity zero-evaporation storage liquid helium tank

technical field

The utility model relates to the technical field of low-temperature tanks/tank containers, in particular to a large-capacity zero-evaporation storage liquid helium tank/tank container.

Background technique

As a non-renewable scarce strategic resource, helium plays an extremely important role in various fields. In high-tech fields such as metallurgy and other industrial production and chip manufacturing, helium can be used in large quantities as protective gas and electronic special gas; in the medical field, helium is mainly used in magnetic resonance equipment, and is liquefied into liquid helium, becoming Coolant for superconducting coils of magnetic resonance equipment; In aerospace engineering, due to the very stable nature of helium, it is used as the driving gas for various pneumatic valves on rockets and the pressurized gas in rocket fuel tanks. Helium has become an indispensable key resource for national security and the development of high-tech industries, and has an important strategic position.

Due to the important position of helium resources as a strategic resource, liquid helium tank containers (also known as liquid helium tank containers) undertake the task of storing and transporting large-capacity liquid helium due to their economy. Compared with other cryogenic liquids, liquid helium has the characteristics of small latent heat, low density, good thermal conductivity and strong diffusivity. Generally, liquid helium tanks store and transport liquid helium under pressure. Compared with ordinary pressure vessels, the structure is more complicated, and the operating load is more. The existing large-capacity liquid helium tanks mostly use liquid nitrogen containers and liquid nitrogen protection screens. Or the structure of multi-screen heat insulation, and several heat insulation methods are also used in combination. Due to the use of existing heat insulation methods, the liquid helium tank container is heated and evaporated due to internal heat leakage or excessive temperature, which makes the interior of the container pressurized. When the pressure of the container exceeds the allowable pressure of the container, it must be discharged and decompressed. Therefore, a large amount of loss and waste of liquid helium will be caused, and there may also be potential safety hazards during the decompression process of the container.

In summary, the existing technology may appear in the process of storing and transporting low-temperature liquefied gas under pressure. Due to heat leakage or excessive temperature inside the liquid helium tank container, the liquid helium is heated and evaporated, and the internal pressurization is too fast and the discharge is reduced. pressure, which will cause a large loss and waste of liquid helium, and may also cause safety hazards during the decompression process of the container.

Utility model content

The embodiment of the utility model provides a large-capacity zero-evaporation storage liquid helium tank/tank container to at least solve the technical problem that the existing liquid helium tank cannot be stored under pressure for a long time and transported for a long time and over a long distance.

According to an embodiment of the present invention, a large-capacity zero-evaporation storage liquid helium tank/tank container is provided, including: the inner container of the liquid helium tank, the cold screen coil of the inner container of the liquid helium tank, the liquid helium inlet Liquid discharge pipe, composite multi-layer insulation material, inner copper screen, flash vapor transmission pipe, thermal insulation support, outer copper screen, liquid helium tank outer container, liquid helium tank steel frame, liquid helium inlet liquid transmission pipeline, cooling medium content Cooling medium inner container cold screen coil, composite multi-layer insulation material II, inner copper screen II, thermal insulation support II, outer copper screen II, low-temperature cold head, low-temperature refrigerator, one-way liquid filling control valve; of which:

The inner container of the liquid helium tank is used to store liquid helium, and the outer side of the inner container of the liquid helium tank is arranged in turn with a cold screen coil, a composite multi-layer insulation material, an inner copper screen, and an outer copper screen;

One end of the liquid helium inlet and discharge pipe passes through the inner container of the liquid helium tank, and is built into the bottom of the inner container of the liquid helium tank. The first layer of heat insulating material, the inner copper screen, the outer copper screen, and the outer container of the liquid helium tank are connected to the helium liquefier or the liquid helium storage container; the inner container of the liquid helium tank is connected to the outer container of the liquid helium tank through an insulating support;

One side of the inner container of the liquid helium tank is arranged with a cooling medium inner container to store helium flash vapor and reliquefied liquid helium, and the outer side is sequentially equipped with a cooling medium inner container cold shield coil, composite multi-layer insulation material II, and an inner copper screen II, outer copper screen II;

One end of the liquid helium inlet transmission pipeline passes through the outer copper screen II, the inner copper screen II, the cold screen coil of the cooling medium inner container, the composite multi-layer insulation material II and the cooling medium inner container, and is built in the lower part of the cooling medium inner container. The other end of the helium inlet liquid transmission pipeline passes through the outer copper screen, inner copper screen, composite multi-layer insulation material and the lower part of the inner container of the liquid helium tank, and connects the inner container of the cooling medium with the inner container of the liquid helium tank, and the liquid helium enters A one-way liquid addition control valve is set on the liquid transmission pipeline;

The cryogenic refrigerator is arranged inside the outer container of the liquid helium tank and the inner container of the cooling medium, wherein the upper part of the cryogenic refrigerator is located inside the outer container of the liquid helium tank and above the outer side of the inner container of the cooling medium, and the middle and lower parts of the cryogenic refrigerator are located in the cooling medium Inside the inner container, the lower part of the low-temperature refrigerator is connected to the low-temperature cold head; the low-temperature cold head is inside the inner container of the cooling medium; one end of the flash gas transmission pipe is connected to the inner container of the cooling medium, and the flash gas transmission pipe passes through the inner container of the cooling medium, and the composite Multi-layer insulation material II, inner copper screen II, outer copper screen II are connected through composite multi-layer insulation material, inner copper screen, outer copper screen and cold screen coil; The rooms are connected by insulating support II.

Furthermore, one end of the liquid helium inlet and discharge pipe passes through the inner container of the liquid helium tank and is built into the bottom of the inner container of the liquid helium tank, and the other end passes through the heat-insulating vacuum pipeline and passes through the composite multi-layer heat-insulating material, the inner copper screen, the outer copper The screen and the outer container of the liquid helium tank are connected with the helium liquefier or the liquid helium storage container.

Further, a liquid inlet and discharge valve is arranged between the outer copper screen and the outer container of the liquid helium tank to realize the flow regulation of the liquid helium tank.

Further, the inner container of the liquid helium tank is wound with a cooling coil of the inner container of the liquid helium tank, and the cooling medium of the cold screen provides cooling capacity for the inner container of the liquid helium tank through the cooling coil.

Furthermore, the outer side of the inner container of the liquid helium tank is an inner copper screen, and a composite multi-layer heat insulating material is wrapped between the inner container of the liquid helium tank and the inner copper screen, and there is an outer copper screen outside the inner copper screen, which is further used to reduce radiation leakage. hot.

Further, there is an outer container of a liquid helium tank on the outside of the outer copper screen, which is used to realize a vacuum environment; the inner container of the liquid helium tank, the inner container of the cooling medium, and the outer container of the liquid helium tank are connected by an insulating support II; the liquid helium tank There is a liquid helium tank steel frame outside the outer container.

Further, the outer copper screen II is arranged on the right side of the outer copper screen, the outer copper screen II contains the inner copper screen II, and the inner copper screen II contains a cooling medium inner container for storing the cooling medium of the liquid helium tank.

Further, the outer side of the inner cooling medium container is wound with a cold shield coil of the inner cooling medium container, and the composite multi-layer thermal insulation material II is filled between the inner cooling medium container and the inner copper screen II.

Further, a low-temperature refrigerator is arranged above and inside the cooling medium inner container, wherein the lower part of the low-temperature refrigerator is connected to the low-temperature cold head; the low-temperature cold head is inside the cooling medium inner container, and is used to cool the cooling medium; the low-temperature refrigerator adopts a pulse tube The refrigerator, G-M refrigerator, thermoacoustic refrigerator or inverse Brayton refrigerator adopts single-stage or double-stage; the low-temperature cold head adopts a first-stage cold head and a second-stage cold head.

Further, one end of the flash gas transmission pipe is included above the cooling medium inner container, and the flash gas transmission pipe passes through the cooling medium inner container, composite multi-layer insulation material II, inner copper screen II, outer copper screen II, adiabatic vacuum pipeline and passes through The composite multi-layer insulation material, the inner copper screen, the outer copper screen and the cold screen coil are connected.

In the large-capacity zero-evaporation storage liquid helium tank/tank container in the embodiment of the utility model, the liquid helium flows into the inner container of the liquid helium tank from the helium liquefier or the liquid helium storage device through the liquid helium inlet and discharge pipe, and then the liquid helium The helium gas produced after evaporation passes through the cold screen coil of the inner container of the liquid helium tank to realize heat absorption and reduce radiation heat leakage. Cool down and liquefy. Part of the cryogenic liquid flows back to the inner container of the liquid helium tank through the liquid helium inlet transmission pipeline, which can cope with the rapid rise of the internal pressure of the liquid helium tank during long-term pressurized storage and long-term, long-distance transportation. Achieve long-term zero evaporation storage.

Description of drawings

The drawings described here are used to provide a further understanding of the utility model and constitute a part of the application. The schematic embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute improper limitations to the utility model. In the attached picture:

Fig. 1 is a structural diagram of a large-capacity zero-evaporation storage liquid helium tank/tank container of the present invention;

Marked in the figure: 1-inner container of liquid helium tank, 2-cooling screen coil of inner container of liquid helium tank, 3-inlet and discharge pipe of liquid helium, 4-composite multi-layer insulation material, 5-inner copper screen, 6-Flash gas transmission pipe, 7-Insulation support, 8-Outer copper screen, 9-Outer container of liquid helium tank, 10-Steel frame of liquid helium tank, 11-Line helium inlet liquid transmission pipeline, 12-Cooling medium content Device, 13-cooling medium inner container cold screen coil, 14-composite multi-layer insulation material II, 15-inner copper screen II, 16-outer copper screen II, 17-low-temperature cold head, 18-low-temperature refrigerator, 19- One-way filling control valve, 20-insulation support II.

Detailed ways

In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the utility model. Obviously, the described The embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

It should be noted that the terms "first" and "second" in the specification and claims of the present utility model and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific order or sequence . It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

In order to better realize the long-term pressurized storage of liquid helium tanks and long-term, long-distance transportation, and avoid a large amount of loss and waste of liquid helium and potential safety hazards during the discharge process, the utility model provides a large-capacity zero-evaporation storage liquid helium The tank container can cope with the rapid rise of internal pressure that is likely to occur during the long-term pressurized storage of liquid helium and the long-term and long-distance transportation of liquid helium in the liquid helium tank container, and realize long-term zero-evaporation storage.

As shown in Figure 1, a large-capacity zero-evaporation storage liquid helium tank/tank container of the present invention includes: a liquid helium tank inner container 1, a liquid helium tank inner container cold screen coil 2, a liquid helium Inlet and discharge pipe 3, composite multi-layer insulation material 4, inner copper screen 5, flash vapor transmission pipe 6, heat insulation support 7, outer copper screen 8, outer container of liquid helium tank 9, steel frame of liquid helium tank 10, liquid helium tank Helium feed liquid transmission pipeline 11, cooling medium inner container 12, cooling medium inner container cold screen coil 13, composite multi-layer insulation material II14, inner copper screen II15, outer copper screen II16, low-temperature cold head 17, low-temperature refrigerator 18, One-way filling control valve 19, heat insulation support II20.

One end of the liquid helium inlet and discharge pipe 3 is connected to the lower part of the inner container 1 of the liquid helium tank, and the other end passes through the heat-insulating vacuum pipeline and passes through the composite multi-layer heat insulating material 4, the inner copper screen 5, the outer copper screen 8, and the outside of the liquid helium tank The container 9 and the liquid helium tank steel frame 10 are connected with the helium liquefier or the liquid helium storage container. A liquid inlet and discharge valve is arranged between the outer copper screen 8 and the outer container 9 of the liquid helium tank to realize the regulation of the liquid inlet/discharge flow. The inner container 1 of the liquid helium tank is wound with a cold screen coil 2 of the inner container of the liquid helium tank, and the cooling medium of the cold screen provides cooling capacity for the inner container 1 of the liquid helium tank through the cold screen coil.

The outer side of the inner container 1 of the liquid helium tank is an inner copper screen 5, and a composite multi-layer heat insulating material 4 is wrapped between the inner container 1 and the inner copper screen 5 of the liquid helium tank, and an outer copper screen 8 is placed outside the inner copper screen 5 for Reduce radiant heat leakage. There is a liquid helium tank outer container 9 outside the outer copper screen 8, which is used to realize the vacuum environment. The outer container 9 of the liquid helium tank is connected to the outer copper screen 8 through the heat insulating support 7, which is used to fix the inner structure such as the outer copper screen 8. There are 10 liquid helium tank steel frames on the outside of the liquid helium tank outer container 9 .

The outer copper screen II16 is arranged on the right side of the outer copper screen 8, the outer copper screen II16 contains the inner copper screen II15, and the inner copper screen II15 contains a cooling medium inner container 12 for storing the cooling medium of the liquid helium tank. The outer side of the cooling medium inner container 12 is wound with a cooling medium inner container cold screen coil 13, and the space between the cooling medium inner container 12 and the inner copper screen II15 is filled with composite multi-layer heat insulating material II14.

One end of the liquid helium feed transmission line 11 is connected to the bottom of the cooling medium inner container 12, and the other end of the liquid helium feed transmission line 11 passes through the outer copper screen 8, the inner copper screen 5, the composite multi-layer insulation material 4 and the liquid helium tank The tank inner container 1 connects the cooling medium inner container 12 with the liquid helium tank inner container 1, and a one-way liquid filling control valve is set on the liquid helium inlet transmission pipeline for controlling and regulating the flow from the cooling medium inner container 12 to the liquid helium tank Liquid helium flow rate for container 1 in the box. The low-temperature refrigerator 18 is arranged inside the outer container 9 of the liquid helium tank and the inner container 12 of the cooling medium, wherein the lower part of the low-temperature refrigerator 18 is connected with the low-temperature cold head 17; the low-temperature cold head 17 is inside the inner container of the cooling medium for cooling Medium cooling.

One end of the flash gas transmission pipe 6 is included above the cooling medium inner container 12, and the flash gas transmission pipe 6 passes through the cooling medium inner container 12, the composite multi-layer insulation material II14, the inner copper screen II15, the outer copper screen II16, the heat-insulated vacuum pipeline and Through the composite multi-layer heat insulation material 4, the inner copper screen 5, the outer copper screen 8 and the cold screen coil 2 are connected to realize the upper communication between the inner container 12 of the cooling medium and the inner container 1 of the liquid helium tank.

During the working process, liquid helium flows from the helium liquefier or liquid helium storage device through the liquid helium inlet and discharge pipe 3 into the inner container 1 of the liquid helium tank, and then the helium gas produced after the evaporation of the liquid helium passes through the cold screen of the inner container of the liquid helium tank The coil 2 realizes heat absorption and reduces radiation heat leakage, and the heated helium enters the cooling medium inner container 12 through the flash gas transmission pipe 6, and is cooled and liquefied under the action of the low-temperature cold head 17. When the liquid level of the inner container of the cooling medium is higher than that of the inner container of the liquid helium tank, the one-way liquid filling control valve 19 can be opened, and part of the cryogenic liquid flows back to the inner container 1 of the liquid helium tank through the liquid helium inlet transmission line 11, realizing long-term Zero evaporative storage.

The beneficial effects of the utility model are:

Compared with the existing best technology, the utility model has the effect that it can cope with the rapid rise of internal pressure in the liquid helium tank during the long-term pressurized storage of liquid helium and the long-term and long-distance transportation of liquid helium. Achieve long-term zero evaporation storage.

Key point/protection point of the present utility model is:

1. The cooling medium inner container is connected to the refrigerator and a low-temperature cold head is arranged above the inside of the cooling medium inner container. The upper part of the cooling medium inner container is connected with the cooling screen coil of the inner container of the liquid helium tank through the flash gas transmission pipe. The lower part of the cooling medium inner container is connected with the inner container of the liquid helium tank through the liquid helium inlet liquid transfer pipeline.

2. The outer side of the inner container of the liquid helium tank is wound with a cold screen coil of the inner container of the liquid helium tank. A cold shield coil of the cooling medium inner container is wound outside the cooling medium inner container.

3. The outer side of the inner container of the liquid helium tank is an inner copper screen, and the outer side of the inner copper screen is an outer copper screen.

4. The outer copper screen II is arranged on the right side of the outer copper screen, the outer copper screen II contains the inner copper screen II, and the inner copper screen II contains the cooling medium inner container.

5. Composite multi-layer insulation material is wrapped between the inner container of the liquid helium tank and the inner copper screen.

6. Composite multi-layer thermal insulation material II is filled between the cooling medium inner container and the inner copper screen II.

7. One end of the liquid helium inlet and discharge pipe is connected to the bottom of the inner container of the liquid helium tank, and the other end passes through the insulated vacuum pipeline and passes through the composite multi-layer insulation material, the inner copper screen, the outer copper screen, the outer container of the liquid helium tank and the helium Liquefier or liquid helium storage vessel connected.

8. The outer container of the liquid helium tank is connected with the inner container of the liquid helium tank and the inner container of the cooling medium through the heat insulation support and the heat insulation support II respectively.

9. There is a steel frame of the liquid helium tank outside the outer container of the liquid helium tank.

The serial numbers of the above-mentioned embodiments of the utility model are only for description, and do not represent the advantages and disadvantages of the embodiments.

In the above-mentioned embodiments of the present invention, the descriptions of each embodiment have their own emphases, and for the parts not described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

In the several embodiments provided in this application, it should be understood that the disclosed technical content can be realized in other ways. Wherein, the system embodiments described above are only illustrative, for example, the division of units can be divided into a logical function, and there may be other division methods in actual implementation, for example, multiple units or components can be combined or integrated into Another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of units or modules may be in electrical or other forms.

A unit described as a separate component may or may not be physically separated, and a component shown as a unit may or may not be a physical unit, that is, it may be located in one place, or may be distributed over multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present utility model is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium Among them, several instructions are included to make a computer device (which may be a personal computer, server or network device, etc.) execute all or part of the steps of the methods in various embodiments of the present invention. The aforementioned storage media include: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes. .

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made, these improvements and Retouching should also be regarded as the scope of protection of the present utility model.

Claims (10)

1. A large-capacity zero-evaporation storage liquid helium tank, characterized in that it includes: the inner container of the liquid helium tank, the cold screen coil of the inner container of the liquid helium tank, the liquid helium inlet and outlet pipes, and the composite multi-layer insulation material , inner copper screen, flash vapor transmission pipe, thermal insulation support, outer copper screen, liquid helium tank outer container, liquid helium tank steel frame, liquid helium inlet liquid transmission pipeline, cooling medium inner container, cooling medium inner container cold screen plate Tube, composite multi-layer insulation material II, inner copper screen II, thermal insulation support II, outer copper screen II, low-temperature cold head, low-temperature refrigerator, one-way liquid filling control valve; of which: The inner container of the liquid helium tank is used to store liquid helium, and the outer side of the inner container of the liquid helium tank is arranged in turn with a cold screen coil, a composite multi-layer insulation material, an inner copper screen, and an outer copper screen; One end of the liquid helium inlet and discharge pipe passes through the inner container of the liquid helium tank, and is built into the bottom of the inner container of the liquid helium tank. The first layer of heat insulating material, the inner copper screen, the outer copper screen, and the outer container of the liquid helium tank are connected to the helium liquefier or the liquid helium storage container; the inner container of the liquid helium tank is connected to the outer container of the liquid helium tank through an insulating support; One side of the inner container of the liquid helium tank is arranged with a cooling medium inner container to store helium flash vapor and reliquefied liquid helium, and the outer side is sequentially equipped with a cooling medium inner container cold shield coil, composite multi-layer insulation material II, and an inner copper screen II, outer copper screen II; One end of the liquid helium inlet transmission pipeline passes through the outer copper screen II, the inner copper screen II, the cold screen coil of the cooling medium inner container, the composite multi-layer insulation material II and the cooling medium inner container, and is built in the lower part of the cooling medium inner container. The other end of the helium inlet liquid transmission pipeline passes through the outer copper screen, inner copper screen, composite multi-layer insulation material and the lower part of the inner container of the liquid helium tank, and connects the inner container of the cooling medium with the inner container of the liquid helium tank, and the liquid helium enters A one-way liquid addition control valve is set on the liquid transmission pipeline; The cryogenic refrigerator is arranged inside the outer container of the liquid helium tank and the inner container of the cooling medium, wherein the upper part of the cryogenic refrigerator is located inside the outer container of the liquid helium tank and above the outer side of the inner container of the cooling medium, and the middle and lower parts of the cryogenic refrigerator are located in the cooling medium Inside the inner container, the lower part of the low-temperature refrigerator is connected to the low-temperature cold head; the low-temperature cold head is inside the inner container of the cooling medium; one end of the flash gas transmission pipe is connected to the inner container of the cooling medium, and the flash gas transmission pipe passes through the inner container of the cooling medium, and the composite Multi-layer insulation material II, inner copper screen II, outer copper screen II are connected through composite multi-layer insulation material, inner copper screen, outer copper screen and cold screen coil; The rooms are connected by insulating support II. 2. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that one end of the liquid helium inlet and discharge pipe passes through the inner container of the liquid helium tank and is built into the bottom of the inner container of the liquid helium tank, and the other One end is connected with the helium liquefier or the liquid helium storage container through the heat-insulated vacuum pipeline and through the composite multi-layer heat-insulation material, the inner copper screen, the outer copper screen, and the outer container of the liquid helium tank. 3. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that a liquid inlet and discharge valve is arranged between the outer copper screen and the outer container of the liquid helium tank to realize the regulation of the flow of liquid in and out of the liquid helium tank. 4. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that, the outer side of the inner container of the liquid helium tank is wound with a cold shield coil of the inner container of the liquid helium tank, and the cooling medium of the cold shield passes through the cold shield The coil provides cooling for the inner vessel of the liquid helium tank. 5. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that the outer side of the inner container of the liquid helium tank is an inner copper screen, and there is a composite coating between the inner container of the liquid helium tank and the inner copper screen. Multi-layer insulation material, with outer copper screen on the outside of the inner copper screen, is further used to reduce radiation heat leakage. 6. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that, there is an outer container of the liquid helium tank outside the outer copper screen for realizing a vacuum environment; the inner container of the liquid helium tank, the cooling medium The inner container and the outer container of the liquid helium tank are respectively connected by heat insulating support and heat insulating support II; there is a steel frame of the liquid helium tank outside the outer container of the liquid helium tank. 7. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that the outer copper screen II is arranged on the right side of the outer copper screen, and the outer copper screen II contains an inner copper screen II, and the inner copper screen II contains a cooling medium inner container for storing the cooling medium of the liquid helium tank. 8. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that, the outer side of the cooling medium inner container is wound with a cooling medium inner container cold screen coil, and between the cooling medium inner container and the inner copper screen II Filled with composite multilayer insulation II. 9. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that a cryogenic refrigerator is arranged above and inside the inner container of the cooling medium, wherein the lower part of the cryogenic refrigerator is connected with a low-temperature cold head; Inside the inner container of the cooling medium, it is used to cool down the cooling medium; the cryogenic refrigerator adopts pulse tube refrigerator, G-M refrigerator, thermoacoustic refrigerator or inverse Brayton refrigerator, and adopts single-stage or double-stage; the cryogenic cold head adopts a Primary cold head and secondary cold head. 10. The large-capacity zero-evaporation storage liquid helium tank according to claim 1, characterized in that an end of a flash gas transmission pipe is included above the cooling medium inner container, and the flash gas transmission pipe passes through the cooling medium inner container, compounded with multiple Layer thermal insulation material II, inner copper screen II, outer copper screen II, thermal insulation vacuum pipeline and pass through composite multi-layer thermal insulation material, inner copper screen, outer copper screen and cold screen coil to connect.