CN112066251B

CN112066251B - Internal fixed support based on conical shell and low-temperature container with same

Info

Publication number: CN112066251B
Application number: CN202010790952.3A
Authority: CN
Inventors: 许鸿昊; 兰玉岐; 卜玉; 张震; 杨昌乐; 许健; 王嘉炜; 安刚
Original assignee: Beijing Aerospace Rate Mechanical & Electrical Engineering Co ltd; Beijing Institute of Aerospace Testing Technology
Current assignee: Aerospace Hydrogen Energy Technology Co ltd
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2022-05-10
Anticipated expiration: 2040-08-07
Also published as: CN112066251A

Abstract

The invention discloses a fixed inner support based on a conical shell and a low-temperature container with the same, and belongs to the technical field of low-temperature containers. The fixed inner support consists of two conical shell parts, each conical shell part is formed by connecting a conical shell, a reinforcing ring and a thick plate, the small end of each conical shell is sealed by the thick plate, the thick plate is provided with a vent hole, and the large end of each conical shell is connected with the reinforcing ring; the thick plates of the two conical shell parts are fixedly connected together, and the large ends of the two conical shell parts are respectively connected with the outer container and the inner container. The invention adopts the thin-wall conical shell structure, occupies small space, is particularly suitable for small-sized low-temperature containers, can obviously reduce the structural heat leakage of the low-temperature container while ensuring the structural strength, particularly avoids the problems of fit clearance and thermal stress caused by the difference of the thermal expansion coefficients of different materials, and has higher working reliability.

Description

Internal fixed support based on conical shell and low-temperature container with same

Technical Field

The invention relates to a conical shell type fixed inner support for a low-temperature liquefied gas storage tank, which is used for connecting an inner container and an outer container of the low-temperature liquefied gas storage tank and belongs to the technical field of low-temperature containers.

Background

The liquefied methane, oxygen, nitrogen, hydrogen, helium and other gases are liquefied, and the liquid volume is far smaller than the gaseous volume, so that the low-temperature liquid storage and transportation is an ideal mode in terms of energy storage density.

In order to reduce heat leakage and evaporation loss of a low-temperature liquid medium, a low-temperature liquefied gas storage tank generally adopts a double-layer structure consisting of an inner container and an outer container, a vacuum interlayer is arranged between the inner container and the outer container, a high-vacuum multi-layer heat insulation mode is used, and the inner container and the outer container are connected through an inner support structure. The inner support structure must be able to bear the weight of the liquid, the weight of the storage tank and the corresponding inertial load, and the heat leakage generated by the inner support structure must be reduced as much as possible, so the inner support structure design is the core of the low-temperature storage tank structure design.

The inner support structure is divided into an axial inner support and a radial inner support. The radial inner support is positioned between the cylinders of the inner container and the outer container, comprises forms of a heat insulation cushion block, a suspender, a sling chain and the like, and is generally used for LNG, liquid oxygen and liquid nitrogen storage tanks; the axial inner support is positioned between the end sockets of the inner container and the outer container, and generally only the axial inner support is used in a liquid hydrogen storage tank and a liquid helium storage tank which have high requirements on heat insulation performance.

Typically, the axial inner support of the cryogenic liquefied gas storage tank consists of a fixed inner support and a sliding inner support, which together bear the gravitational and inertial loads from the inner vessel and the medium. The fixed inner support is relatively highly loaded and carries not only the vertical and lateral loads from the inner vessel and media, but also the axial load from the inner vessel alone.

The axial fixed inner supporting structure of the low-temperature liquefied gas storage tank has the following three types:

(1) fixed support based on glass steel thermal insulation. Taking patent zl00216678.x as an example, as shown in fig. 1, the fixed inner support is composed of a metal component and a glass fiber reinforced plastic component, and the heat insulation mainly depends on the low heat conduction coefficient of the glass fiber reinforced plastic material. The disadvantages of this support are: the thermal expansion coefficient of the glass fiber reinforced plastic is obviously larger than that of metal, and the glass fiber reinforced plastic has anisotropy and is easy to generate fit clearance or thermal stress at low temperature.

(2) Fixed support based on metal lamination. Taking an 840L liquid hydrogen Dewar truck for liquid hydrogen air transportation by NBS in the United states as an example, as shown in figure 2, the fixed inner support is made of metal members completely, and the heat insulation mainly depends on a metal lamination heat insulation support. The metal lamination heat insulation support is formed by compounding a large number of extremely thin metal laminations, and the heat insulation capacity equivalent to that of glass fiber reinforced plastics is formed by utilizing the contact heat resistance among the metal laminations, so that the strength is hardly influenced, and the problem of inconsistent thermal expansion coefficients does not exist. The disadvantages of this support are: the metal lamination has higher manufacturing difficulty and cost, and is not suitable for popularization occasions.

(3) Based on the fixed support of concentric sleeve pipe. Taking patent ZL201810336146.1 as an example, as shown in fig. 3, the fixed inner support is formed by concentrically sleeving a plurality of thin-wall metal pipes with different diameters, and the heat insulation mainly depends on a heat bridge formed by a plurality of thin-wall metal pieces. The disadvantages of this support are: the sleeve is slender, has weak bearing capacity and large deformation, and is easy to form a thermal short circuit.

Disclosure of Invention

In view of the above, the invention provides a fixed inner support based on a conical shell and a low-temperature container with the same, wherein the inner support controls heat leakage through a thin-wall conical shell structure, the structure is simple, and the problems of fit clearance and thermal stress caused by different thermal expansion coefficients of different materials are solved.

A fixed inner support based on a conical shell is composed of two thin-wall conical shell parts, each thin-wall conical shell part is formed by connecting a conical shell, a reinforcing ring and a thick plate, the small end of the conical shell is sealed by the thick plate, the thick plate is provided with a vent hole, and the large end of the conical shell is connected with the reinforcing ring; the thick plates of the two thin-wall conical shell parts are fixedly connected together, and the large ends of the two thin-wall conical shell parts are respectively connected with the outer container and the inner container.

Further, the value range of the vertex angle of the conical shell is 5-90 degrees.

Furthermore, adjacent thick plates of the two thin-wall conical shell parts are fixedly connected, and can be connected in various modes such as welding, fastening connection, concave-convex surface embedding and matching and the like.

Furthermore, an auxiliary structure can be additionally arranged between the thick plates of the cone shell piece.

Further, the auxiliary structure can be made of glass fiber reinforced plastics to improve thermal resistance or made of metal to introduce cold.

Further, the cone shell part is connected with the outer container end socket and the inner container end socket directly or through an adapter structure.

Furthermore, the outer surface of the fixed inner support is covered with a heat insulating material, the inner cavity of the fixed inner support is filled with a heat insulating material, and the heat insulating material is preferably a vacuum multilayer heat insulating material, glass wool, rock wool, expanded perlite and the like.

Further, the fixed inner support is manufactured in an additive mode through one-step forming.

A low-temperature container with a fixed inner support comprises an outer container, an inner container, the fixed inner support, a sliding inner support, a switching ring and a sealing cover; one ends of the outer container and the inner container are relatively fixed through the fixed inner supports, and the other ends of the outer container and the inner container are connected through the sliding inner supports, so that the relative sliding of the inner container and the outer container is realized; one end of the fixed inner support is fixedly connected with the end socket on the outer container, the other end of the fixed inner support is fixedly connected with the end socket on the inner container, the fixed inner support is connected with the switching ring on the outer container, and the switching ring is provided with a sealing cover and serves as a vacuum seal of the low-temperature liquefied gas storage tank.

Furthermore, an adapter structure is designed between the fixed inner support and the inner container to reduce the axial length of the outer container, the adapter structure is composed of a concave cylinder and a seal head which are arranged on the inner container, and the fixed inner support part is embedded into the inner container through the concave cylinder.

Has the advantages that:

1. the thin-wall conical shell part adopts a thin-wall structure to control heat leakage, does not depend on the heat insulation performance of non-metallic materials, and avoids a series of problems of fit clearance, thermal stress and the like caused by the difference of thermal expansion coefficients of different materials.

2. The fixed inner support adopts paired thin-wall conical shell pieces, has large sections at two ends, small section at the middle section and small occupied space, is particularly suitable for small-sized low-temperature containers, and can obviously reduce the heat leakage of the structure while ensuring the structural strength. In addition, the outer surface and the inner part of the thin-wall conical shell can be provided with heat insulation structures such as a vacuum multilayer heat insulation quilt and the like, and an auxiliary structure can be additionally arranged between thick plates of two thin-wall conical shell parts, so that a way is provided for application of other mature heat insulation technologies.

3. The invention has low manufacturing difficulty, is suitable for batch production and has wide application and popularization prospects.

Drawings

FIG. 1 is a schematic view of a prior art fixed support structure based on glass fiber reinforced plastic insulation;

FIG. 2 is a schematic view of a prior art fixed support structure based on metal laminations;

FIG. 3 is a schematic view of a prior art concentric sleeve based stationary support structure;

FIG. 4 is a schematic structural view of the cone shell component of the present invention;

FIG. 5 is a schematic view of a cone shell based fixed internal support structure of the present invention;

FIG. 6 is a graph of bending moment of the fixed inner support;

FIG. 7 is a cryogenic liquefied gas storage tank with a cone shell fixed inner support;

FIG. 8 is a schematic view of the fastening of two cone shell members using bolt sets;

FIG. 9 is a schematic structural view of the conical shell with glass fiber reinforced plastic added between the conical shell members;

FIG. 10 is a cryogenic liquefied gas storage tank with outside dimensions not being limited;

FIG. 11 is a cryogenic liquefied gas storage tank with limited physical dimensions;

the device comprises a conical shell 1, a reinforcing ring 2, a thick plate 3, an air vent 4, a conical shell 5, a conical shell 6, an outer container 7, an inner container 8, a fixed inner support 9, an adapter ring 10, a sealing cover 11, a sliding inner support 12, glass fiber reinforced plastic 13, a saddle-type support 14 and an adapter structure 15.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

The invention provides a fixed inner support based on a conical shell. The individual cone shell members are shown in fig. 4. The conical shell is formed by connecting a conical shell 1, a reinforcing ring 2 and a thick plate 3, wherein the range of the vertex angle alpha value of the conical shell 1 is 5-90 degrees, the reinforcing ring 2 is connected with the large end of the conical shell 1, and the thick plate 3 is connected with the small end of the conical shell 1. The conical shell part is provided with a vent hole 4, and the vent hole 4 is preferably arranged on the thick plate 3.

As shown in fig. 5, the fixed inner support is composed of a conical shell member 5 and a conical shell member 6, the thick plates at the small ends of the conical shell member 5 and the conical shell member 6 are adjacent and fixedly connected, and the specific connection mode may be welding or fastening connection of bolt sets; an auxiliary structure made of glass fiber reinforced plastics or metal can be arranged between the end surfaces of the two thick plates; the conical shell part 5 is fixedly connected with the outer container 7, can be directly connected with an outer container end enclosure, and can also be connected with the outer container end enclosure through a switching structure; the conical shell part 6 is fixedly connected with the inner container 8, can be directly connected with the inner container end socket, and can also be connected with the inner container end socket through a switching structure. Under vertical downward gravitational or inertial loads, cone shell 5 is subjected to upward force F from outer container 7 and cone shell 6 is subjected to downward force F from inner container 8. Because the rigidity of the inner container and the outer container is far greater than that of the two conical shell parts, and the axes of the inner container and the outer container are parallel to each other, the fixed support formed by the two conical shell parts follows a beam model with one end fixedly supported and the other end with zero corner. According to this model, the cone 5 receives a bending moment M from the outer vessel 7, and the cone 6 receives a bending moment M from the inner vessel 8, where M is FL/2.

As shown in fig. 6, under the above forces and bending moments, different cross sections of the fixed inner support bear different bending moments, the bending moment reaches the maximum at the two ends of the support, and reaches the minimum at the middle of the support, which is close to zero.

Under the action of a vertical downward load, the load bearing of the middle part of the fixed inner support is obviously smaller than that of the two ends of the fixed inner support. The conical shell type fixed inner support has the characteristic of variable cross section, has large two ends and small middle, meets the bearing characteristic of the fixed inner support, and can more fully utilize the structural strength.

As shown in fig. 7, the present invention further provides a cryogenic liquefied gas storage tank with the above-mentioned fixed inner support structure, wherein one end of the fixed inner support 9 is fixedly connected with the end socket of the outer container 7, and the other end is fixedly connected with the end socket of the inner container 8, so as to realize the relative fixation of the inner container 8 with respect to the left end of the outer container 7; the fixed inner support 9 is connected with an adapter ring 10 on the outer container, and the adapter ring 10 is provided with a sealing cover 11 and used as a vacuum seal of the low-temperature liquefied gas storage tank; the sliding inner support 12 is matched with the fixed inner support 9, and can realize the relative sliding of the right ends of the inner container 8 and the outer container 7, thereby avoiding obvious thermal stress generated by thermal expansion and cold contraction.

First embodiment of the fixed inner support:

as shown in fig. 8, a connection mode of fastening and combining a concave-convex surface and a bolt group is adopted between two sleeve cones of the fixed inner support, and the connection mode is reliable and convenient to assemble and manufacture.

Second embodiment of fixed inner support:

on the basis of the first fixed inner support embodiment, other structures can be additionally arranged between the joint surfaces of the two sleeve cones, and other mature heat insulation technologies are introduced, for example, glass fiber reinforced plastics 13 are arranged, as shown in fig. 9, so that the heat leakage of the structures can be further reduced.

First embodiment of cryogenic liquefied gas storage tank:

without limitation to the overall dimensions of the cryogenic liquefied gas storage tank, the fixed inner support may be fixedly connected directly to the inner vessel which is supported on the ground or other equipment by means of saddle supports 14, as shown in figure 10. Therefore, the inner container has thinner wall thickness, small manufacturing difficulty and low manufacturing cost.

Second embodiment of cryogenic liquefied gas storage tank:

for mobile cryogenic liquefied gas storage tanks, there are often limitations on the overall size of the storage tank. In this case, an adapter 15 can be provided between the fixed inner support and the inner container, which consists of a small cylinder and a small end cap, as shown in fig. 11, so that the fixed inner support can be partially inserted into the inner container, and the axial length of the outer container can be significantly reduced. However, the inner container sealing head is provided with a large hole, so that the inner container sealing head needs to be reinforced, the wall thickness of the sealing head is thick, and the manufacturing cost is correspondingly increased.

In the above examples, the support structure of the cryogenic liquefied gas storage tank is taken as an example of a saddle, but the patent is also applicable to cryogenic tank containers, cryogenic tank trucks and the like using other container supports.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fixed inner support based on a conical shell is characterized by comprising two conical shell parts, wherein each conical shell part is formed by connecting a conical shell, a reinforcing ring and a thick plate, the small end of the conical shell is sealed by the thick plate, the thick plate is provided with a vent hole, and the large end of the conical shell is connected with the reinforcing ring; the thick plates of the two conical shell parts are fixedly connected together, and the large ends of the two conical shell parts are respectively connected with the outer container and the inner container; the outer surface of the fixed inner support is covered with a heat insulating material, and the inner cavity of the fixed inner support is filled with the heat insulating material.

2. The cone shell based fixed inner support of claim 1, wherein the cone shell apex angle ranges from 5 ° to 90 °.

3. The cone shell based fixed inner support of claim 1 or 2, wherein adjacent planks of the two cone shell pieces are fixedly connected by welding, fastening or surface-relief-surface-embedded fitting.

4. The cone shell based fixed inner support of claim 3, wherein secondary structure is provided between the planks.

5. The cone shell based fixed inner support of claim 4, wherein the secondary structure can be made of glass fiber reinforced plastic to increase thermal resistance or metal to induce cold.

6. The cone shell based fixed inner support of claim 5, wherein the cone shell member is connected to the outer vessel head and the inner vessel head directly or through an adapter structure.

7. A cryogenic vessel having a fixed inner support as claimed in any one of claims 1 to 6, wherein the cryogenic vessel comprises an outer vessel, an inner vessel, a fixed inner support, a sliding inner support, an adapter ring and a closure cap; one ends of the outer container and the inner container are relatively fixed through the fixed inner supports, and the other ends of the outer container and the inner container are connected through the sliding inner supports, so that the relative sliding of the inner container and the outer container is realized; one end of the fixed inner support is fixedly connected with the end socket on the outer container, the other end of the fixed inner support is fixedly connected with the end socket on the inner container, the fixed inner support is connected with the switching ring on the outer container, and the switching ring is provided with a sealing cover and serves as a vacuum seal of the low-temperature liquefied gas storage tank.

8. The cryogenic vessel of claim 7 wherein an adapter structure is designed between the fixed inner support and the inner vessel to reduce the axial length of the outer vessel, the adapter structure is composed of a concave cylinder and a sealing head arranged on the inner vessel, and the fixed inner support is partially embedded into the inner vessel through the concave cylinder.