CN112066250A

CN112066250A - Fixed inner support based on concentric sleeve cone and low-temperature container with same

Info

Publication number: CN112066250A
Application number: CN202010790916.7A
Authority: CN
Inventors: 许鸿昊; 兰玉岐; 卜玉; 张震; 余炳延; 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: 2020-12-11
Anticipated expiration: 2040-08-07
Also published as: CN112066250B

Abstract

The invention discloses a fixed inner support based on a concentric sleeve cone 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 sleeve cones, the sleeve cones are formed by sequentially connecting the head and the tail of a plurality of cone shells with different inner diameters and close vertex angles in a sleeved mode, a certain distance is kept between every two adjacent cone shells, the small end of the cone shell at the innermost layer is sealed by a thick plate, the thick plate is provided with a vent hole, and the large end of the cone shell at the outermost layer is open to form a labyrinth-shaped heat bridge structure; the two sleeve cones are fixedly connected together through a thick plate, and the large ends of the cone shells at the outermost layers of the two sleeve cones are respectively connected with the outer container and the inner container. The sleeve cone labyrinth structure is adopted, the occupied space is small, the structural heat leakage of the low-temperature container can be obviously reduced while the structural strength is ensured, particularly, the problems of fit clearance and thermal stress caused by the difference of thermal expansion coefficients of different materials are solved, and the working reliability is higher.

Description

Fixed inner support based on concentric sleeve cone and low-temperature container with same

Technical Field

The invention relates to a concentric sleeve cone 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; in addition, in the figure, the point A is a hot end, the point B is a cold end, an effective heat insulation structure is difficult to arrange between the points AB, and a heat bridge is difficult to play an application role.

Disclosure of Invention

In view of the above, the invention provides a fixed inner support based on a concentric sleeve cone and a low-temperature container with the same, wherein the inner support controls heat leakage through a labyrinth structure, 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 concentric sleeve cones is composed of two sleeve cones, wherein the sleeve cones are formed by sequentially connecting a plurality of cone shells with different inner diameters and similar vertex angles in an end-to-end mode after being sleeved, a certain distance is kept between every two adjacent cone shells, the small end of the cone shell at the innermost layer is sealed by a thick plate, an air vent is formed in the thick plate, and the large end of the cone shell at the outermost layer is open to form a labyrinth-shaped heat bridge structure; the thick plates of the two sleeve cones are fixedly connected together, and the large ends of the cone shells at the outermost layers of the two sleeve cones 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.

Further, the large end and the small end of the conical shell are connected together through a ring-shaped piece.

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

Further, an auxiliary structure is arranged between the thick plates.

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

Further, the sleeve cone 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. according to the single sleeve cone, a plurality of cone shells with different inner diameters and similar vertex angles are sleeved and then sequentially connected end to form a labyrinth structure to control heat leakage, the heat insulation performance of a non-metal material is not depended on, and a series of problems of fit clearance, thermal stress and the like caused by the difference of thermal expansion coefficients of different materials are avoided.

2. The fixed inner support adopts a paired thin-wall sleeve cone structure, the sections of two ends are large, the section of the middle section is small, the space is saved, the bearing capacity can be ensured, and the heat leakage of the structure is reduced. In addition, the outer surface and the inner part of the sleeve cone can be provided with heat insulation structures such as a vacuum multi-layer heat insulation quilt, and auxiliary structures can be additionally arranged between thick plates of the double sleeve cone, so that a way is provided for the application of other mature heat control technologies.

3. The invention has moderate 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 a concentric cone set of the present invention;

FIG. 5 is a schematic view of a fixed internal support structure based on concentric cones according to 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 concentric mantle 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 two conical shell members with the addition of glass fiber reinforced plastic insulation therebetween;

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;

wherein, 1-conical shell, 2-conical shell, 3-conical shell, 4-thick plate, 5-annular piece, 6-annular piece, 7-annular piece, 8-vent hole, 9-sleeve cone, 10-sleeve cone, 11-outer container, 12-inner container, 13-fixed inner support, 14-sliding inner support, 15-adapter ring, 16-sealing cover, 17-glass fiber reinforced plastic, 18-saddle and 19-adapter structure.

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 concentric sleeve cones, which consists of two concentric sleeve cones. A single concentric cone is shown in fig. 4. The conical shell is formed by sleeving a conical shell 1, a conical shell 2 and a conical shell 3 which are different in size, wherein the conical shells are suitable to adopt similar vertex angles alpha, the alpha value range is 5-90 degrees, a certain distance is ensured among the conical shells, and the distance is generally not less than 3 mm; the small end of the conical shell 3 is connected with a thick plate 4; the small end of the conical shell 1 is connected with the small end of the conical shell 2 through an annular piece 5; the big end of the conical shell 2 is connected with the big end of the conical shell 3 through an annular part 6; the big end of the cone shell 1 is connected with a ring-shaped part 7, and the parts form a labyrinth-shaped heat bridge structure together. The concentric sleeve cone is provided with a vent hole 8, and the vent hole 8 is preferably arranged on the thick plate 4.

As shown in fig. 5, the fixed inner support is composed of a sleeve cone 9 and a sleeve cone 10, the sleeve cone 9 is adjacent to the thick plate at the small end of the sleeve cone 10 and is fixedly connected, and the specific connection mode can be welding or bolt group fastening connection; an auxiliary structure made of glass fiber reinforced plastic or metal can be arranged between the end surfaces of the two thick plates; the sleeve cone 9 is fixedly connected with the outer container 11, 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 sleeve cone 10 is fixedly connected with the inner container 12, 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 gravity or inertial loading, cone 9 is subjected to upward force F from outer vessel 11 and cone 10 is subjected to downward force F from inner vessel 12. Because the rigidity of the inner container and the outer container is far greater than that of the two sleeve cones, and the axes of the inner container and the outer container are parallel to each other, the fixed support formed by the two sleeve cones follows a beam model with one end fixedly supported and the other end with zero corner. According to this model, the mantle cone 9 receives a bending moment M from the outer vessel 11, and the mantle cone 10 receives a bending moment M from the inner vessel 12, 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 sleeve cone 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. It is estimated that the heat leakage of the concentric cone-in-sleeve structure is reduced by about 25% compared to the concentric sleeve structure at the same load carrying capacity.

As shown in fig. 7, the present invention further provides a cryogenic liquefied gas storage tank having the above-mentioned fixed inner support structure, wherein one end of the fixed inner support 13 is fixedly connected to the end socket of the outer container 11, and the other end is fixedly connected to the end socket of the inner container 12, so as to realize the relative fixation of the inner container 12 with respect to the left end of the outer container 11; the fixed inner support 13 is connected with an adapter ring 15 on the outer container, and the adapter ring 15 is provided with a sealing cover 16 and used as a vacuum seal of the low-temperature liquefied gas storage tank; the sliding inner support 14 is used together with the fixed inner support 13, and can realize the relative sliding of the right ends of the inner container 12 and the outer container 11, thereby avoiding the obvious thermal stress generated by thermal expansion and cold contraction. According to estimation, the sleeve cone type fixed inner support is applied to the low-temperature liquefied gas storage tank, so that the total heat leakage can be reduced by about 5 percent, and the evaporation of the low-temperature liquefied gas is reduced; the application in a mobile low-temperature liquefied gas storage tank can prolong the maintenance time.

First embodiment of the fixed inner support:

as shown in FIG. 8, in consideration of the inconvenience of flaw detection during welding, the connection mode of fastening and combining the concave-convex surface and the bolt group is adopted between the two sleeve cones of the fixed inner support, and the connection mode is reliable and convenient to assemble and manufacture.

Fixed inner support embodiment two:

on the basis of the first embodiment of the fixed inner support, other structures, such as glass fiber reinforced plastics 17, can be additionally arranged between the joint surfaces of the two sleeve cones, as shown in fig. 9, so that the thermal resistance of the fixed inner support can be further improved, and the heat leakage of the structure can be 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 and the outer vessel supported on the ground or other equipment by means of saddles 18, 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 structure 19, which consists of a small cylinder and a small end cap, can be provided between the fixed inner support and the inner container, 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 structures of the cryogenic liquefied gas storage tank are taken as saddles, but the patent is also applicable to cryogenic tank containers, cryogenic tank cars 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 concentric sleeve cones is characterized in that the fixed inner support consists of two sleeve cones, the sleeve cones are formed by sequentially connecting a plurality of cone shells with different inner diameters and close vertex angles in an end-to-end mode after being sleeved, a certain distance is kept between every two adjacent cone shells, the small end of the cone shell at the innermost layer is sealed by a thick plate, the thick plate is provided with an air vent, and the large end of the cone shell at the outermost layer is open to form a labyrinth-shaped heat bridge structure; the two sleeve cones are fixedly connected together through a thick plate, and the large ends of the cone shells at the outermost layers of the two sleeve cones are respectively connected with the outer container and the inner container.

2. A fixed inner support based on concentric mantle cones according to claim 1, characterised in that the apex angle of the cone shell ranges from 5 ° to 90 °.

3. A fixed inner support based on concentric sleeves as claimed in claim 1 or 2, wherein the big end and the small end of the cone shell are connected together by a ring.

4. The concentric cone sleeve based stationary inner support of claim 3, wherein adjacent planks of two cone sleeves are fixedly connected by welding, fastening or surface-relief-fit.

5. The concentric cone sleeve based stationary inner support of claim 4, wherein secondary structures are provided between the slabs.

6. The concentric cone based fixed inner support of claim 5, wherein the secondary structure is made of glass fiber reinforced plastic to increase thermal resistance or is made of metal to introduce cold.

7. A fixed inner support based on concentric cones as claimed in claim 6, wherein the cones are connected with the outer vessel head and the inner vessel head directly or through an adapter structure.

8. The concentric mantle cone-based fixed inner support of claim 7, wherein an outer surface of the fixed inner support is covered with a thermally insulating material, and an inner cavity of the fixed inner support is filled with a thermally insulating material.

9. A cryogenic vessel having a fixed inner support according to any one of claims 1 to 8, 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.

10. The cryogenic vessel of claim 9 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.