Interlayer supporting structure for high-vacuum heat insulation tank body

Abstract

The invention discloses an interlayer supporting structure for a high-vacuum heat insulation tank, the high-vacuum heat insulation tank comprises a shell and an inner container, the shell and the inner container form an interlayer, the axial front end of the interlayer is provided with four sliding ends, and the axial rear end of the interlayer is provided with four fixed ends; the fixed end comprises a shell supporting cover connected with the inner wall of the shell and an inner container supporting cover connected with the outer wall of the inner container, the shell supporting cover and the inner container supporting cover are oppositely arranged, do not make contact with each other and form a first cavity, and a composite supporting piece is arranged in the first cavity. The structure of the fixed end is optimized, a plurality of layers of stacked glass fiber reinforced plastic pieces are adopted to prolong a heat conduction path and increase contact heat resistance, the embedded stainless steel reinforcing pieces are adopted to replace the glass fiber reinforced plastic pieces to bear shear loads, and the bearing capacity of the structure is improved on the premise that the heat insulation performance is not affected; the technical problems that in the prior art, the heat insulation requirement cannot be met at the same time, and the bearing requirement can not be met without additionally arranging an auxiliary device are solved.

Description

Technical Field

[0001] The invention belongs to the field of vacuum insulation tanks and relates to a support structure, in particular to a sandwich support structure for a high vacuum insulation tank. Background Art

[0002] In the double-layer high vacuum insulated tank, the sandwich support is a structural component connecting the inner container and the outer shell. First of all, it must meet the connection function, that is, limit all degrees of freedom of the inner container relative to the outer shell, and be able to withstand the loads under all possible working conditions of the tank truck and the worst possible combination. Secondly, the insulation requirements must be guaranteed. The support will inevitably become a conductive heat bridge while bearing the load. It is necessary to increase the thermal resistance by extending the path or selecting low thermal conductivity materials. However, extending the path will make the structural rigidity worse. Low thermal conductivity materials are mostly non-metallic materials with strength far lower than that of steel. Both methods will weaken the bearing capacity. Thirdly, after the inner container is loaded with low-temperature media, it will produce non-negligible temperature deformation. The support structure must have sufficient adaptability to avoid excessive temperature stress or load transfer failure caused by shrinkage and detachment of components.

[0003] In Chinese patent CN201310503618.5, the existing high vacuum insulation tank interlayer support technology is relatively mature. For the medium in the liquid nitrogen temperature zone, the interlayer support adopts the traditional "eight-point support" structure to well take into account the functional requirements of both insulation and load-bearing. In this structure, the four sliding ends press the FRP pipe on the inner container support seat through the outer shell support cover to position the inner container in the horizontal and vertical directions, and the FRP pipe bears the compression load parallel to the cloth layer direction; in addition to positioning in the horizontal and vertical directions, the four fixed ends also insert the FRP pipe into the outer shell support cover and the inner container support cover at the same time to limit the longitudinal displacement and circumferential rotation of the inner container. The FRP pipe also bears the compression load and shear load perpendicular to the cloth layer direction.

[0004] When it is a mobile container with a large load, the vertical and longitudinal inertial forces in the load conditions of the sandwich support are also greatly affected. If the load is only carried by the four FRP pipes at the fixed end, it will be crushed due to the lack of insertion contact area and material compression strength, or cut due to insufficient material shear strength, and the load cannot be properly transmitted. If the FRP pipe is thickened to meet the strength requirements, even if the length of the FRP pipe is increased within the range allowed by the structure to extend the heat conduction path, it cannot meet the insulation performance requirements at the same time.

[0005] Alternatively, the "eight-point support" can be changed to a sliding end form, and a tie rod or stop device can be added between the inner container and the outer shell to limit the longitudinal displacement of the inner container. In order to avoid excessive increase of thermal bridges, the new support must also find ways to extend the heat conduction path, and solve the resulting assembly error compensation problem and strength problem caused by the significant increase in weight, as well as a series of process problems caused by the resulting structural complexity. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a sandwich support structure for a high vacuum insulated tank body to solve the technical problem that the prior art cannot simultaneously meet the insulation requirements and the load-bearing requirements without adding additional auxiliary devices.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0008] A sandwich support structure for a high vacuum thermal insulation tank, the high vacuum thermal insulation tank comprising an outer shell and an inner container, the outer shell and the inner container forming a sandwich, the axial front end of the sandwich being provided with four sliding ends, and the axial rear end of the sandwich being provided with four fixed ends;

[0009] The fixed end includes an outer shell support cover connected to the inner wall of the outer shell and an inner container support cover connected to the outer wall of the inner container, the outer shell support cover and the inner container support cover are arranged opposite to each other, do not contact and form a first cavity, a composite support member is arranged in the first cavity, and the composite support member includes a first fiberglass pad, a first tubular fiberglass ring, a plurality of plate-type fiberglass rings, a second tubular fiberglass ring and a second fiberglass pad, which are arranged in sequence from bottom to top; the first fiberglass pad, the first tubular fiberglass ring, a plurality of plate-type fiberglass rings, the second tubular fiberglass ring and the second fiberglass pad form a second cavity, and a stainless steel reinforcement is arranged in the second cavity.

[0010] The present invention also includes the following technical features:

[0011] Two pairs of symmetrically distributed ribs are arranged on the outer side wall of the shell support cover.

[0012] The stainless steel reinforcement is transitionally matched with the second cavity.

[0013] The outer shell support cover and the inner container support cover are both oblong cylinders with one end face open, and the interiors thereof are cavities.

[0014] The outer edges of the first FRP pad, the first tubular FRP collar and the plate-type FRP collar are in the same shape, the first FRP pad has the same structure as the second FRP pad, and the first tubular FRP collar has the same structure as the second tubular FRP collar.

[0015] The stainless steel reinforcement is an oblong cylinder, which is provided with a plurality of through holes distributed along the axial direction.

[0016] The arrangement direction of the first tubular FRP collar and the second tubular FRP collar is circumferential, and the arrangement direction of the first FRP pad, the plate-shaped FRP collar and the second FRP pad is axial.

[0017] The plate-shaped glass fiber reinforced plastic sleeve rings are provided in 3 to 4 numbers.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] (I) In the present invention, the structure of the fixed end is optimized, and multiple layers of stacked fiberglass parts are used to extend the heat conduction path and increase the contact thermal resistance. Embedded stainless steel reinforcement parts are used instead of fiberglass parts to bear the shear load, thereby improving the bearing capacity of the structure without affecting the thermal insulation performance. This solves the technical problem that the prior art cannot simultaneously meet the thermal insulation requirements and meet the bearing requirements without adding additional auxiliary devices.

[0020] (II) The structure of the present invention limits the freedom of the inner container relative to the outer shell in a manner consistent with the traditional "eight-point support" form, which is mature and reliable, does not require additional auxiliary devices, and avoids the problem of structural complexity.

[0021] (III) The present invention does not significantly increase weight, cost and process complexity, and is conducive to popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the installation of the present invention on a high vacuum insulation tank;

[0023] Figure 2 It is a structural schematic diagram of the fixed end in the present invention;

[0024] Figure 3 It is an exploded view of the fixed end in the present invention;

[0025] Figure 4 is a longitudinal cross-sectional view of the fixed end in the present invention;

[0026] Figure 5 is a transverse cross-sectional view of the fixed end in the present invention;

[0027] Figure 6 It is a schematic diagram of the arrangement direction of the tubular glass fiber reinforced plastic sleeve in the present invention;

[0028] Figure 7 It is a schematic diagram of the layout direction of the glass fiber reinforced plastic pad in the present invention;

[0029] Figure 8 It is a schematic diagram of the arrangement direction of the plate-shaped glass fiber reinforced plastic sleeve in the present invention.

[0030] The meanings of the various reference numerals in the figure are: sliding end 1, fixed end 2, housing 3, inner container 4;

[0031] Outer shell support cover 201, inner container support cover 202, first FRP pad 203, first tubular FRP collar 204, plate FRP collar 205, second tubular FRP collar 206, second FRP pad 207, stainless steel reinforcement 208, ribs 209, through hole 2010.

[0032] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0033] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0034] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0035] The present invention provides a sandwich support structure for a high vacuum insulation tank body, such as Figure 1 to Figure 3 The high vacuum insulated tank body comprises an outer shell 3 and an inner container 4, wherein the outer shell 3 and the inner container 4 form an interlayer, wherein the axial front end of the interlayer is provided with four sliding ends 1, and the axial rear end of the interlayer is provided with four fixed ends 2;

[0036] The fixed end 2 includes an outer shell support cover 201 connected to the inner wall of the outer shell and an inner container support cover 202 connected to the outer wall of the inner container. The outer shell support cover 201 and the inner container support cover 202 are arranged opposite to each other, do not contact, and form a first cavity. A composite support member is arranged in the first cavity. The composite support member includes, from bottom to top, a first FRP pad 203, a first tubular FRP ring 204, a plurality of plate-type FRP rings 205, a second tubular FRP ring 206, and a second FRP pad 207; the first FRP pad 203, the first tubular FRP ring 204, a plurality of plate-type FRP rings 205, the second tubular FRP ring 206, and the second FRP pad 207 form a second cavity, and a stainless steel reinforcement member 208 is arranged in the second cavity.

[0037] In the above technical scheme, the structure of the fixed end 1 is optimized, and multiple layers of stacked fiberglass parts are used to extend the heat conduction path and increase the contact thermal resistance. Embedded stainless steel reinforcement parts are used instead of fiberglass parts to bear the shear load. The bearing capacity of the structure is improved without affecting the insulation performance, which solves the technical problem that the prior art cannot simultaneously meet the insulation requirements and the bearing requirements without adding additional auxiliary devices.

[0038] In the above technical scheme, the sliding end 1 and the fixed end 2 are both arranged between the outer shell 3 and the inner container 4 of the high vacuum insulation tank body. The structure of the sliding end 1 in this scheme is an existing structure, that is, the sliding support assembly in Chinese patent CN201310503618.5 (inner and outer tank support structure), that is, it includes an outer tank support cover fixedly arranged on the outer shell 3 and an inner tank sliding support plate arranged on the inner container 4, and a glass fiber reinforced plastic support fixedly arranged in the outer tank support cover;

[0039] Both the sliding end 1 and the fixed end 2 are used to limit the lateral and vertical displacement of the inner container 4 relative to the outer shell 3. The sliding end 1 is used to fix the front end of the inner container 4, while the improved fixed end 2 is responsible for fixing the rear end of the inner container. Among them, since the fixed end 2 is provided with a composite support member in the inner container support cover 202, the two have an assembly relationship and cannot undergo longitudinal displacement. However, the fiberglass support is in contact with the inner tank sliding support plate on the inner container but is not fixed without obstruction, and can slide longitudinally when the inner container 4 and the outer shell 3 expand and contract asynchronously.

[0040] See also Figure 4-5 When subjected to vertical load, the load transfer path is: inner container support cover 202 → composite support member → outer shell support cover 201. Inside the composite support member, there are two parallel load transfer paths:

[0041] Path 1 is: first FRP pad 203 → first tubular FRP collar 204 → plate-shaped FRP collar 205 → second tubular FRP collar 206 → second FRP pad 207;

[0042] Path two is: first FRP pad 203 → stainless steel reinforcement 208 → second FRP pad 207 .

[0043] The stress-bearing area (i.e., the oblong area) of this composite support is more than twice the circular area of ​​the traditional structure, and the loading direction of most FRP parts is perpendicular to the cloth layer direction, which has higher compressive strength.

[0044] When subjected to longitudinal load and tangential load, the load transfer path is: outer shell support cover 201 → first tubular fiberglass collar 204 → stainless steel reinforcement 208 → second tubular fiberglass collar 206 → inner container support cover 202 .

[0045] In this transmission path, the first tubular FRP collar 204 and the second tubular FRP collar 206 are only compressed but not sheared, and the shearing action is borne by the stainless steel reinforcement 208. In order to further improve the stress of the FRP collar, the depth of the support cover is increased, thereby increasing the insertion depth of the FRP collar.

[0046] Since the longitudinal load is greater than the tangential load, the composite support with an oblong cross-section is set in the direction where the straight edge is perpendicular to the longitudinal load. When subjected to the longitudinal load, the force-bearing area (i.e., the product of the oblong projection length and the insertion depth) is greatly increased compared with the traditional structure, and the loading direction of the FRP collar (the direction of the force borne by the part) is perpendicular to the cloth layer direction, which avoids the FRP part from being crushed. The FRP collar and the stainless steel reinforcement in the composite support adopt transition fit, and the gap between the FRP collar and the support cover is also strictly controlled to prevent impact when transferring load.

[0047] The fixed end serves as a heat conduction bridge between the inner container and the outer shell, and the heat transfer path is: outer shell support cover 201 → first FRP pad 203 and first tubular FRP collar 204 → stainless steel reinforcement 208 and plate-type FRP collar 205 → second tubular FRP collar 206 and second FRP pad 207 → inner container support cover 202.

[0048] Due to the increase in the stress area when bearing the load, the average heat conduction cross-sectional area in this path is increased compared with the traditional form, but the deepening of the support cover also extends the length of the path. In addition, the thermal conductivity of epoxy glass fiber reinforced plastic pipes and plates is smaller in the direction perpendicular to the cloth layer. This characteristic is used to arrange the glass fiber reinforced plastic parts reasonably. Based on this calculation and verification, the results show that the heat transfer of the support in the present invention is basically the same as that in the traditional form. In addition, the glass fiber reinforced plastic support in the traditional form is a whole, and the composite support is used in the present invention. There is a certain contact thermal resistance between the glass fiber reinforced plastic parts and between the glass fiber reinforced plastic parts and the stainless steel reinforcement parts. Since its resistance value cannot be quantified, it is not included in the calculation. Therefore, in practical applications, the thermal insulation performance of the fixed end support in the present invention can meet the requirements.

[0049] Among them, when the high vacuum insulated tank body is set on a vehicle, the longitudinal direction refers to the driving direction of the vehicle, that is, parallel to the axis of the tank body; the vertical direction refers to vertically upward or downward; the transverse direction refers to the direction perpendicular to both the vertical and longitudinal directions, such as the shaking direction of the vehicle when it moves forward.

[0050] In this technical solution, according to the load-bearing and insulation requirements of different media for their containers, when the load-bearing requirements are reduced and the insulation requirements are increased, the stainless steel reinforcement 208 in the composite support can be replaced with a non-metallic material with lower strength but greater thermal resistance.

[0051] In the present technical solution, when the stacked FRP rings alone are capable of bearing the vertical load, the height of the stainless steel reinforcement 208 in the composite support can be changed to be slightly lower than the height of the stacked rings, so as to ensure the shear resistance but not contact the first FRP pad 203 and the second FRP pad 207 at both ends at the same time. This can cut off part of the heat transfer path and further improve the thermal insulation performance.

[0052] Two pairs of symmetrically distributed ribs 209 are provided on the outer side wall of the shell support cover 201 .

[0053] In the above technical solution, the shell support cover 201 protrudes a certain height from the shell 3, destroying the integrity of the shape of the shell 3. The provision of the ribs 209 can alleviate the stress concentration at the structural mutation point.

[0054] The stainless steel reinforcement 208 and the second cavity are in transition fit.

[0055] In the above technical solution, the transition fit can effectively eliminate the gaps between the stainless steel reinforcement 208 and the first tubular FRP collar 204, the plurality of plate-type FRP collars 205 and the second tubular FRP collar 206 to avoid impact.

[0056] The outer shell support cover 201 and the inner container support cover 202 are both oblong cylinders with one end surface open, and the interior thereof is a cavity.

[0057] In the above technical solution, such a setting can increase the force-bearing area of ​​the composite support to reduce the pressure. The cross section of the original support is circular, and increasing its diameter can also increase the force-bearing area, but on the one hand, the longitudinal force is much greater than the lateral force, and on the other hand, the predetermined spacing of the reinforcement ring of the shell 3 also limits the increase in the diameter of the composite support. Therefore, a support with an oblong cylindrical shape with different longitudinal and lateral widths is used, and the width direction is perpendicular to the direction of the longitudinal force.

[0058] Preferably, an ellipse, a rounded rectangle, etc. may also be used, which can also play the same role.

[0059] The outer edges of the first FRP pad 203, the first tubular FRP ring 204 and the plate-shaped FRP ring 205 are of the same shape, the first FRP pad 203 and the second FRP pad 207 have the same structure, and the first tubular FRP ring 204 and the second tubular FRP ring 206 have the same structure.

[0060] In the above technical solution, such an arrangement can form a constraint to limit the vertical and lateral displacement of the inner container 4 relative to the outer shell 3, and the above displacement trends are respectively generated by gravity and inertia. Gravity and inertia are vector-decomposed into forces perpendicular to the cross-section of the composite support member and balanced by the support reaction force provided by the composite support member. The strength of the composite support member meets the support requirements to curb the above displacement trend. When the composite support member used in this technical solution plays the above role, the multi-layer stacked fiberglass parts are only subjected to pressure perpendicular to the board surface direction, and the size of the board surface area meets the strength requirements. At the same time, the total height of the multi-layer stacked fiberglass parts is also the length of the heat transfer path, and the board surface area of ​​the fiberglass parts is also the cross-sectional area of ​​the heat transfer path. From the perspective of thermal insulation, the longer the path length, the better, and the smaller the cross-sectional area, the better.

[0061] The stainless steel reinforcement 208 is an oblong cylinder having a plurality of through holes 2010 distributed along the axial direction.

[0062] In the above technical solution, a through hole 2010 is opened on the stainless steel reinforcement 208 to reduce the heat transfer area. One to three through circular holes are opened, and the circular holes are located in the center or evenly distributed to avoid the tube wall being too thin in some places. The remaining cross-sectional area first meets the shear resistance requirements of the stainless steel reinforcement, and secondly should be reduced as much as possible to weaken the conductive heat flow.

[0063] The cross-sectional shape of the stainless steel reinforcement 208 can be changed to a rounded rectangle or an ellipse, and the one or more larger circular holes can be changed to smaller circular holes or special-shaped holes arranged in a bar grid or a grid.

[0064] The first tubular FRP collar 204 and the second tubular FRP collar 206 are arranged in a circumferential direction, and the first FRP pad 203, the plate-shaped FRP collar 205 and the second FRP pad 207 are arranged in an axial direction.

[0065] In the above technical scheme, FRP has both good strength and low thermal conductivity, and is a material with better performance when used for thermal insulation support. FRP is an anisotropic material, as shown in Table 1. The different layer directions of FRP parts are set to make the structure more adaptable to the corresponding load-bearing conditions by utilizing the material properties. When the loading direction (the direction of the force borne by the part) of the FRP parts is different, the mechanical properties are not the same. When the loading direction (the direction of the force borne by the part) is perpendicular to the layer direction, the compression strength is high and the thermal conductivity is small. When the loading direction is parallel to the layer direction, it is just the opposite. In addition to transmitting the pressure in the direction of the plate surface, the first tubular FRP sleeve 204 and the second tubular FRP sleeve 206 also need to transmit a larger pressure generated by the longitudinal inertial force acting on the circumference of the sleeve, so the layer direction is circumferential. The remaining FRP parts only transmit the pressure in the direction of the plate surface, and occupy the vast majority of the heat transfer path, so the layer direction is axial.

[0066] Table 1 Physical and mechanical properties of epoxy glass fiber reinforced plastic pipe materials for low temperature insulation

[0067]

[0068] There are 3 to 4 plate-shaped glass fiber reinforced plastic collars 205 .

[0069] In the above technical solution, the number of the plate-shaped fiberglass sleeve rings 205 is specifically set according to the thermal insulation requirements.

Claims

1. A sandwich support structure for a high vacuum thermal insulation tank, the high vacuum thermal insulation tank comprising an outer shell (3) and an inner container (4), wherein the outer shell (3) and the inner container (4) form a sandwich, characterized in that: The axial front end of the interlayer is provided with four sliding ends (1), and the axial rear end of the interlayer is provided with four fixed ends (2); The fixed end (2) comprises an outer shell support cover (201) connected to the inner wall of the outer shell and an inner container support cover (202) connected to the outer wall of the inner container. The outer shell support cover (201) and the inner container support cover (202) are arranged opposite to each other, do not contact each other and form a first cavity. A composite support member is arranged in the first cavity. The composite support member comprises a first glass fiber reinforced plastic pad (203), a first tubular glass fiber reinforced plastic collar (204), a plurality of plate-shaped glass fiber reinforced plastic collars (205), a second tubular glass fiber reinforced plastic collar (206) and a second glass fiber reinforced plastic pad (207) arranged in sequence from bottom to top. The first glass fiber reinforced plastic pad (203), the first tubular glass fiber reinforced plastic collar (204), a plurality of plate-shaped glass fiber reinforced plastic collars (205), the second tubular glass fiber reinforced plastic collar (206) and the second glass fiber reinforced plastic pad (207) form a second cavity. A stainless steel reinforcement member (208) is arranged in the second cavity.

2. The sandwich support structure for a high vacuum insulation tank as claimed in claim 1, characterized in that: Two pairs of symmetrically distributed ribs (209) are provided on the outer side wall of the outer shell support cover (201).

3. The sandwich support structure for a high vacuum insulation tank as claimed in claim 1, characterized in that: The stainless steel reinforcement (208) and the second cavity are in transitional fit.

4. The sandwich support structure for a high vacuum insulation tank as claimed in claim 1, characterized in that: The outer shell support cover (201) and the inner container support cover (202) are both oblong cylinders with one end face open, and the interiors thereof are hollow.

5. The sandwich support structure for a high vacuum insulation tank as claimed in claim 1, characterized in that: The outer edges of the first FRP pad (203), the first tubular FRP collar (204) and the plate-shaped FRP collar (205) are of the same shape; the first FRP pad (203) and the second FRP pad (207) are of the same structure; and the first tubular FRP collar (204) and the second tubular FRP collar (206) are of the same structure.

6. The sandwich support structure for a high vacuum insulation tank as claimed in claim 1, characterized in that: The stainless steel reinforcement (208) is an oblong cylinder having a plurality of through holes (2010) distributed along the axial direction.

7. The sandwich support structure for a high vacuum insulation tank as claimed in claim 1, characterized in that: The first tubular FRP collar (204) and the second tubular FRP collar (206) are arranged in a circumferential direction, and the first FRP pad (203), the plate-shaped FRP collar (205) and the second FRP pad (207) are arranged in an axial direction.

8. The sandwich support structure for a high vacuum insulation tank as claimed in claim 1, characterized in that: The plate-shaped glass fiber reinforced plastic sleeve rings (205) are provided in 3 to 4 numbers.

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