Three-step type heat preservation enclosure system suitable for large low-temperature liquid tank

Abstract

According to the three-step type heat preservation enclosure system suitable for the large low-temperature liquid tank, each heat preservation plate unit is integrally formed into a three-step structure which is gradually shrunk in the direction away from the surface of the large low-temperature liquid tank; the step structures of the plurality of mutually spliced heat insulation board units jointly form a low-position heat insulation layer, a middle-position heat insulation layer and a high-position heat insulation layer; the buffer units are arranged between the heat preservation layers of the adjacent heat preservation plate units, and the elasticity of the buffer units corresponding to the low-position heat preservation layer and the high-position heat preservation layer is larger than that of the buffer units corresponding to the middle-position heat preservation layer. The fixing unit fixes each insulation board unit on the surface of the large low-temperature liquid tank. According to the invention, the problem of mutual position movement among the thermal insulation layers is avoided, the overall structure of the thermal insulation enclosure system is more stable, buffer compensation is provided for deformation of the thermal insulation layers so as to avoid deformation and cracking of the thermal insulation board units and the influence of gaps between the adjacent thermal insulation board units on the thermal insulation effect, and the waste of buffer performance is avoided to the greatest extent.

Description

Technical Field

[0001] The present invention relates to the technical field of tank enclosure, and in particular to a three-step thermal insulation enclosure system applicable to large cryogenic liquid tanks. Background Art

[0002] Under the background of the rapid development of the new energy industry, as an important clean energy sector, the market demand for LNG (liquefied natural gas) has also increased rapidly. The preparation and transportation processes of LNG mainly rely on storage in a liquefied state in large cryogenic liquid tanks. Therefore, high requirements are put forward for the thermal insulation enclosure system of large cryogenic liquid tanks. In the prior art, the insulation boards are cut into rectangles or squares, and several insulation boards are arranged in an array on the surface of the liquid tank, and buffer strips are inserted into the gaps between adjacent insulation boards. However, since the low temperature transmitted from the large cryogenic liquid tank to the insulation board has a gradient, that is, the area of the insulation board close to the surface of the large cryogenic liquid tank bears a lower temperature, and the deformation amount of the insulation board due to low temperature is larger, higher buffer performance is required from the buffer strips. On the one hand, the provided buffer performance is used to prevent gaps from appearing between adjacent insulation boards during use due to temperature deformation, thereby affecting the thermal insulation effect on the large cryogenic liquid tank. On the other hand, since the insulation board material has a relatively large linear expansion coefficient compared with the steel plate, the provided buffer performance is used to prevent the insulation board from deforming and cracking. Correspondingly, this will cause waste of buffer performance in the area far from the surface of the large cryogenic liquid tank.

[0003] To solve this problem, the prior art has also developed stepped insulation boards. A total of three layers of insulation boards with gradually decreasing dimensions in the direction away from the surface of the large liquid tank are provided, and the three layers of insulation boards are stacked and assembled to form three thermal insulation layers. By differentially setting the buffer strips corresponding to the three thermal insulation layers, the problem of buffer performance waste is solved. However, due to the problem of connection firmness between the three layers of insulation boards, the relative positions of the three layers of insulation boards will also move. The buffer strip setting method in the prior art only considers the situation where the relative positions of the three layers of insulation boards move. If the stepped insulation board is integrally formed and there is no problem of relative position movement between the three layers of insulation boards, since the relative position movement directly affects the buffer performance, the buffer strip setting method cannot meet the requirements. At the same time, during the hoisting process of the large cryogenic liquid tank, the external force will also cause the insulation board to deform, thereby also causing a decrease in the thermal insulation performance of the thermal insulation system. The buffer strip setting method in the prior art does not consider this situation either. Summary of the Invention

[0004] To solve at least one of the above-mentioned many problems, the present invention provides a three-step thermal insulation enclosure system applicable to large cryogenic liquid tanks.

[0005] Specifically, the present invention is realized through the following technical solutions:

[0006] An embodiment of the present invention provides a three-step thermal insulation enclosure system applicable to large cryogenic liquid tanks, including: a thermal insulation board unit, a number of thermal insulation board units are fixed on the surface of the large cryogenic liquid tank in a horizontal and vertical array, and each thermal insulation board unit is integrally formed into a three-step structure that tapers away from the surface of the large cryogenic liquid tank, so that the respective step structures of a number of mutually spliced thermal insulation board units jointly form a low-level thermal insulation layer, a middle-level thermal insulation layer, and a high-level thermal insulation layer, wherein the low-level thermal insulation layer is close to the surface of the large cryogenic liquid tank, the high-level thermal insulation layer is far from the surface of the large cryogenic liquid tank, and the middle-level thermal insulation layer is located between the low-level thermal insulation layer and the high-level thermal insulation layer;

[0007] A buffer unit, which is arranged between the respective thermal insulation layers of adjacent thermal insulation board units, wherein the elasticity of the buffer units corresponding to the low-level thermal insulation layer and the high-level thermal insulation layer is greater than that of the buffer unit corresponding to the middle-level thermal insulation layer;

[0008] A fixing unit, which fixes each thermal insulation board unit on the surface of the large cryogenic liquid tank.

[0009] In some embodiments, between adjacent thermal insulation board units of the low-level thermal insulation layer, the buffer unit is a first buffer strip in a compressed state.

[0010] In some embodiments, among the first buffer strips that are orthogonal to each other, the first buffer strips in one direction extend continuously, and the first buffer strips in the other direction are intermittently abutted against the side surfaces of the first buffer strips in the one direction.

[0011] In some embodiments, between adjacent thermal insulation board units of the high-level thermal insulation layer, the buffer unit is a third buffer strip. Among the third buffer strips that are orthogonal to each other, the third buffer strips in one direction extend continuously, and the third buffer strips in the other direction are intermittently abutted against the side surfaces of the third buffer strips in the one direction.

[0012] In some embodiments, between adjacent thermal insulation board units of the middle-level thermal insulation layer, the buffer unit is a second buffer strip and a buffer block. Among the second buffer strips that are orthogonal to each other, the second buffer strips in both directions jointly abut against the side surface of the buffer block.

[0013] In some embodiments, the second buffer strip is provided with a buffer base strip, and an elastic groove is formed in the buffer base strip, so that the second buffer strip can elastically deform in the horizontal direction; or, the second buffer strip is provided with a buffer base strip, and elastic strips are arranged on both sides of the buffer base strip, so that the second buffer strip can elastically deform in the horizontal direction.

[0014] In some embodiments, a sealing layer is pasted on the surface of the corresponding step structure between the respective thermal insulation layers of adjacent thermal insulation units.

[0015] In some embodiments, the fixing unit is arranged as a connecting column, the heat preservation board unit is formed with a through hole penetrating the board thickness, the connecting column penetrates through the heat preservation board unit through the through hole, and both ends of the connecting column are fixed to the surface of the large-scale cryogenic liquid tank and the end piece respectively. Among them, a stepped hole is formed at the end of the through hole in the direction away from the surface of the large-scale cryogenic liquid tank, and a retaining piece and a sealed heat preservation block are sequentially arranged in the stepped hole.

[0016] In some embodiments, the first buffer strip is glass wool or elastic felt in a compressed state with a compression ratio of 2.5 - 3.8 times. Among them, the resilience coefficient K of the elastic felt is not less than 44%, and the thermal conductivity is not higher than 0.04 w / (m·K); or, the buffer base strip of the second buffer strip is made of the same material as the heat preservation board unit.

[0017] In some embodiments, the buffer base strip of the second buffer strip is made of glass fiber reinforced polyurethane material, and the heat preservation board unit is made of polyurethane material.

[0018] According to the embodiments of the present invention, the heat preservation board unit is arranged as a three-step structure formed by integral molding, which avoids the problem of mutual position movement between each heat preservation layer and makes the overall structure of the heat preservation enclosure system more stable; for the integral molding three-step structure, by setting the buffer unit corresponding to the low-temperature heat preservation layer to have high elasticity, when the low-temperature heat preservation layer has a large deformation due to low temperature, the high-elasticity buffer unit can compensate for the gap deformation between the heat preservation board units in real time; by setting the buffer unit corresponding to the high-temperature heat preservation layer to have high elasticity, when the high-temperature heat preservation layer has a large deformation due to hoisting, the high-elasticity buffer unit can compensate for the gap deformation between the heat preservation board units in real time; by setting the buffer unit corresponding to the middle-temperature heat preservation layer to have relatively low elasticity, since the deformation amount in the middle-temperature heat preservation layer area is relatively small, the waste of buffering performance is avoided to the greatest extent, the deformation and cracking of the heat preservation board unit and the gap between adjacent heat preservation board units are avoided, and the heat preservation effect of the large-scale cryogenic liquid tank is ensured.

[0019] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0021] Figure 1 is a schematic diagram of a three-step heat preservation enclosure system applicable to a large-scale cryogenic liquid tank in an embodiment of the present invention;

[0022] Figure 2 is an exploded view of a three-step heat preservation enclosure system applicable to a large-scale cryogenic liquid tank in an embodiment of the present invention;

[0023] Figure 3 is a cross-sectional view of a three-step thermal insulation and enclosure system applicable to a large-scale cryogenic liquid tank in an embodiment of the present invention;

[0024] Figure 4 is Figure 3 a partial enlarged view at position A in

[0025] Figure 5 is a partial cross-sectional view of a three-step thermal insulation and enclosure system applicable to a large-scale cryogenic liquid tank in another embodiment of the present invention;

[0026] Figure 6 is Figure 3 a partial enlarged view at position B in

[0027] Figure 7 is a deformation-load test diagram of an elastic felt in an embodiment of the present invention.

[0028] Reference numerals:

[0029] 10: thermal insulation board unit; 11: low-level thermal insulation layer; 12: middle-level thermal insulation layer; 13: high-level thermal insulation layer;

[0030] 21: first buffer strip; 22: second buffer strip; 221: elastic groove; 222: buffer base strip; 223: elastic strip; 23: third buffer strip; 24: buffer block;

[0031] 31: first sealing layer; 32: second sealing layer; 33: third sealing layer;

[0032] 41: connecting column; 42: end piece; 43: retaining piece; 44: sealed thermal insulation block;

[0033] 50: tank body. Detailed implementation manners

[0034] The present invention will now be described with reference to several embodiments. It should be understood that the description of these embodiments is only for enabling those of ordinary skill in the art to better understand and thus implement the present invention, rather than implying any limitation on the scope of the present invention.

[0035] As used herein, the term "including" and its variants are to be construed as open-ended terms meaning "including but not limited to"; the terms "embodiment" and "one embodiment" are to be construed as "at least one embodiment"; the term "another embodiment" is to be construed as "at least one other embodiment"; the terms "first", "second", etc. may refer to different or the same objects; the term "arranged" is not limited to direct connection or indirect connection, nor to a specific connection manner. There may also be other explicit and implicit definitions hereinafter.

[0036] In the following description, some specific numerical values or numerical ranges may be involved. It should be understood that these numerical values and numerical ranges are merely exemplary and may be conducive to putting the idea of the present invention into practice. However, the description of these examples is not intended to limit the scope of the present invention in any way. According to specific application scenarios and requirements, these numerical values or numerical ranges can be set otherwise.

[0037] As described above, the existing thermal insulation enclosure system cannot provide sufficient buffering for the insulation board integrally formed into a stepped structure and the deformation of the insulation board during the hoisting process. The three-step thermal insulation enclosure system applicable to large cryogenic liquid tanks proposed in the embodiments of the present invention at least partially solves the above problems. The following will refer to Figures 1-7 to describe the structure and working principle of the three-step thermal insulation enclosure system applicable to large cryogenic liquid tanks according to the exemplary embodiments of the present invention. The three-step thermal insulation enclosure system applicable to large cryogenic liquid tanks in the embodiments of the present invention mainly includes an insulation board unit 10, a buffer unit, a sealing unit, and a fixing unit. There are multiple insulation board units 10, and the multiple insulation board units 10 are fixedly arranged in a horizontal and vertical array on the surface of the large cryogenic liquid tank, so as to jointly form the main body part with the thermal insulation function of the thermal insulation enclosure structure; the buffer unit is arranged in the gap between adjacent insulation board units 10 and is used to digest the gaps generated due to processing errors and the gaps generated due to the deformation of the insulation board during use; the sealing unit is used to provide a sealing and moisture-proof effect between each thermal insulation layer; the fixing unit is used to fix the insulation board unit 10 on the surface of the large cryogenic liquid tank.

[0038] It should be noted that the three-step thermal insulation enclosure system in the embodiments of the present invention can be used in any cryogenic liquid tank thermal insulation occasion. Exemplarily, it can be used in cryogenic storage tanks such as chemical raw materials, pharmaceutical raw materials, and LNG. For the convenience of description, the following takes the LNG cryogenic liquid tank corresponding to the B-type independent cargo tank as an example to explain the structure and principle of the embodiments of the present invention. Those skilled in the art can understand that the structure and principle are also applicable to marine A-type and C-type independent cargo tanks, as well as non-independent integral cargo tanks and internal adiabatic storage tanks, and are also applicable to non-marine large cryogenic liquid tanks.

[0039] The insulation board unit 10 is integrally formed into a three-step structure by insulating materials. The insulation board closest to the surface of the large cryogenic liquid tank has the largest size, so that the insulation area of the low-position insulation layer 11 formed is the largest. The insulation board farthest from the surface of the large cryogenic liquid tank has the smallest size. With such a setting, the insulation materials can maximize the thermal insulation effect and avoid material waste. On this basis, to improve the processability of integral forming, the size of the middle step is also between the two.

[0040] In one embodiment, the thermal insulation board unit 10 can be made of polyurethane, foam glass, foam ceramics, rock wool, calcium silicate, polystyrene (EPS) or vacuum insulation panel. Preferably, using polyurethane (PUF) not only has the thermal insulation function, but also can provide sufficient strength and deformation ability, making the thermal insulation enclosure system have better overall structural strength and thermal insulation performance.

[0041] In one embodiment, the stepped structure of the thermal insulation board unit 10 is directly cut and formed from a rectangular thermal insulation board. After forming, the three-layer stepped structures are stably connected to each other and will not move relative to each other.

[0042] Multiple thermal insulation board units 10 are spliced together. The three-layer stepped structures respectively form three thermal insulation layers, which are, in order from near the large cryogenic liquid tank to far from the large cryogenic liquid tank, the low-position thermal insulation layer 11, the middle-position thermal insulation layer 12, and the high-position thermal insulation layer 13. Among them, the low-position thermal insulation layer 11 bears the lowest temperature, resulting in the largest deformation of the thermal insulation board. The high-position thermal insulation layer 13 bears the highest temperature, but has the largest deformation caused by the lifting external force. Therefore, the buffer units corresponding to the low-position thermal insulation layer 11 and the high-position thermal insulation layer 13 should also have the greatest elasticity accordingly, so as to sufficiently compensate for the gap change between adjacent thermal insulation board units 10.

[0043] Specifically, the buffer unit corresponding to the low-position thermal insulation layer 11 is the first buffer strip 21. Since the size of the thermal insulation board unit 10 in the area of the low-position thermal insulation layer 11 is the largest and the gap between adjacent thermal insulation board units 10 is the smallest, the first buffer strip 21 to be inserted is in the shape of a thin sheet. To make it have sufficient buffering capacity, glass wool is selected. After being compressed about 2.5 - 3.8 times, the glass wool is inserted into the gap. Exemplarily, the 50mm glass wool is compressed to 13 - 20mm and then inserted into the gap, so that the glass wool has sufficient elastic recovery ability.

[0044] In another embodiment, in order to have better elastic recovery ability, an elastic felt with better resilience can be selected. It has excellent compression performance and resilience performance, high tensile strength, and good thermal insulation performance. The elastic felt is formed by three-dimensional fiber structure of glass fibers and fixed at high temperature. Among them, the resilience coefficient of the elastic felt directly affects the buffering performance it can provide in the gap between thermal insulation board units, and the thermal conductivity of the elastic felt directly affects the temperature transfer barrier performance of the gap area between thermal insulation board units. Therefore, the elastic felt selected in the embodiment of the present invention has a resilience coefficient K≥44% and a thermal conductivity ≤0.04W / (m·K) (average temperature 0°C). The deformation-load test situation of this elastic felt is as Figure 7 shown. In the embodiment of the present invention, the elastic felt is compressed about 2.5 - 3.8 times and then inserted into the gap. Exemplarily, the 50mm glass wool is compressed to 13 - 20mm and then inserted into the gap, so that the elastic felt has sufficient buffering performance and temperature transfer barrier performance.

[0045] In one embodiment, taking four adjacent thermal insulation board units 10 shown in Figure 1 and Figure 2 as an example, the four thermal insulation board units 10 together form a "plus" shaped gap, that is, two mutually orthogonal gaps. In the lower thermal insulation layer 11, the first buffer strip 21 in one direction extends through the length, and the first buffer strip 21 in the other direction is intermittently abutted against its side surface. With such a setting, as described above, the deformation amount of the lower thermal insulation layer 11 is relatively large, and the first buffer strip 21 will also deform due to the lower position in its length extension direction. The through-length first buffer strip 21 can compensate for this deformation amount.

[0046] The buffer unit corresponding to the upper thermal insulation layer 13 is the third buffer strip 23. The size of the thermal insulation board unit 10 in the area of the upper thermal insulation layer 13 is the smallest, and the corresponding heat preservation area of the formed upper thermal insulation layer 13 is also the smallest, saving thermal insulation board materials. As described above, the deformation amount of the upper thermal insulation layer 13 under the action of the hoisting external force is large. The third buffer strip 23 is also made of a material with high elasticity, which can ensure sufficient buffering capacity for the gaps between adjacent thermal insulation board units 10 in the area of the upper thermal insulation layer 13. Exemplarily, the third buffer strip 23 is prepared from polyethylene material (PEF), which can provide sufficient elastic recovery ability.

[0047] In one embodiment, as shown in Figure 1 and Figure 2 , in the upper thermal insulation layer 13, the third buffer strip 23 in one direction extends through the length, and the third buffer strip 23 in the other direction is intermittently abutted against its side surface. With such a setting, as described above, the upper thermal insulation layer 13 is deformed greatly due to the hoisting external force, and the third buffer strip 23 will also deform due to the upper position in its length extension direction. The through-length third buffer strip 23 can compensate for this deformation amount.

[0048] The buffer unit corresponding to the middle thermal insulation layer 12 is the second buffer strip 22. As described above, the temperature borne by the middle thermal insulation layer 12 has been appropriately increased after passing through the lower thermal insulation layer 11. The deformation amount of the thermal insulation board affected by temperature in this area is relatively small, and at the same time, the deformation amount brought by the hoisting external force is also relatively small. To avoid waste of buffering performance, the second buffer strip 22 is selected as an adiabatic material with a relatively small elastic recovery ability or no elastic recovery ability but with a certain strength support ability. Exemplarily, using polyurethane (PUF) can provide heat preservation ability, and at the same time, it is matched with the thermal insulation board unit 10 also made of polyurethane (PUF), so that the overall heat preservation performance of the entire middle thermal insulation layer 12 is balanced.

[0049] In another embodiment, considering the problem of gap buffering and sealing between the insulation board units, the second buffer strip 22 is made of glass fiber-reinforced polyurethane (RPUF), while the insulation board units are made of polyurethane (PUF) with better heat preservation effect. The glass fiber-reinforced polyurethane has greater strength, less usage at the gaps, and little impact on the heat preservation performance of the enclosure system as a whole, but it can compensate for the mechanical properties at the gaps.

[0050] As described above, since the deformation amount of the middle insulation layer 12 is small, as Figure 1 and Figure 2 shown, a buffer block 24 is provided at the center position of the "plus" - shaped gap formed by the four insulation board units 10. The four side surfaces of the buffer block 24 are respectively abutted against the four second buffer strips 22. With such a setting, during the installation process of the thermal insulation enclosure system, the buffer block 24 is first inserted into the center position, and then the four second buffer strips 22 are inserted into the gap and abutted against its side surfaces, making the whole installation process simpler. Exemplarily, the buffer block 24 can also be made of polyurethane (PUF) material.

[0051] Although there is no overly high requirement for the buffering performance that the second buffer strip 22 needs to possess, in the optimal solution, it is desired that the second buffer strip 22 has at least a certain elastic recovery ability in the horizontal direction. The "horizontal direction" mentioned here refers to the direction along the step surface of the step structure of the insulation board unit 10.

[0052] In one embodiment, the second buffer strip 22 is provided with a buffer base strip 222, and an elastic groove 221 is opened in the buffer base strip 222. The elastic groove 221 can be continuous or discontinuous in the extending direction of the buffer base strip 222. The extending direction of the elastic groove 221 is orthogonal to the horizontal direction, so as to provide the second buffer strip 22 with the ability of elastic deformation in the horizontal direction. Exemplarily, the number of the elastic grooves 221 can be one, or two or more. As Figure 4 described, the two elastic grooves 221 are respectively opened at positions close to both sides of the buffer base strip 222.

[0053] In one embodiment, as Figure 5 shown, elastic strips 223 are additionally provided on both sides of the buffer base strip 222 of the second buffer strip 22. The buffer base strip 222 provides the heat preservation function, and the buffer base strip 222 can be made of the same material as the insulation board unit. Exemplarily, the buffer base strip 222 is made of polyurethane (PUF) material. The elastic strips 223 provide the elastic recovery ability. Exemplarily, the elastic strips 223 are made of polyethylene material (PEF) material, so that the second buffer strip 22 has buffering ability in the horizontal direction. The buffer base strip 222 can also be made of a material different from that of the insulation board unit. Exemplarily, the insulation board unit is made of polyurethane (PUF), and the buffer base strip 222 is made of glass fiber-reinforced polyurethane (RPUF).

[0054] In one embodiment, the sealing unit includes a first sealing layer 31, a second sealing layer 32, and a third sealing layer 33. The first sealing layer 31 is adhered to the surface of the stepped structure above the first buffer strip 21 for moisture-proofing between the gaps of the low-temperature insulation layer 11 and the middle-temperature insulation layer 12. The second sealing layer 32 is adhered to the surface of the stepped structure above the second buffer strip 22 for moisture-proofing between the gaps of the middle-temperature insulation layer 12 and the high-temperature insulation layer 13. The third sealing layer 33 is adhered to the surface of the stepped structure above the third buffer strip 23 for moisture-proofing between the gap of the high-temperature insulation layer 13 and the external environment. In one embodiment, the first sealing layer 31, the second sealing layer 32, and the third sealing layer 33 can be made of CAC composite film, that is, a glass fiber structure composite film with aluminum foil. The CAC composite film is formed by laminating three layers of glass fiber cloth, aluminum foil, and glass fiber cloth with an adhesive.

[0055] In another embodiment, the sealing unit can include only one or two of the first sealing layer 31, the second sealing layer 32, and the third sealing layer 33. That is to say, it is not necessary to provide moisture-proofing functions between every two spaces of the gaps of the low-temperature insulation layer 11, the gaps of the middle-temperature insulation layer 12, the gaps of the high-temperature insulation layer 13, and the external environment.

[0056] In one embodiment, between the sealing unit and the surface of the stepped structure, it can be adhered through an adhesive, or the sealing unit can be directly adhered by hot pressing.

[0057] In one embodiment, each insulation board unit 10 is fixed to the surface of the large cryogenic liquid tank through a fixing unit. As Figure 6 shown, the fixing unit includes a connecting column 41 and an end piece 42. The connecting column 41 passes through the through hole formed through the insulation board unit 10. One end of the connecting column 41 is directly fixed to the tank body 50 of the large cryogenic liquid tank. A partition board can also be laid between the insulation board unit and the tank body 50. The connecting column 41 passes through the hole formed in the partition board. Exemplarily, the partition board can be a wooden board. The end piece 42 is connected to the connecting column 41 from the other end. Exemplarily, the end piece 42 can be a nut, and the end of the connecting column 41 can be formed with a matching external thread. Exemplarily, the connecting column 41 can be a connecting screw made of wood material.

[0058] In one embodiment, a stepped hole is formed at the end of the through hole in the direction away from the surface of the large cryogenic liquid tank. A retaining piece 43 and a sealed insulation block 44 are sequentially arranged in the stepped hole. The end piece 42 is pressed against the stepped surface of the stepped hole through the retaining piece 43. Exemplarily, the retaining piece 43 is made of wood material. A sealed insulation block 44 is further inserted above the retaining piece 43 and the end piece 42 for providing sealing to the through hole and buffering compensation to the stepped hole. Exemplarily, the sealed insulation block 44 can be made of the same material as the insulation board unit, or can be made of compressed glass wool with a proportion of about 50%.

[0059] In the description of the embodiments herein, any reference to directions and orientations is for the convenience of description only and should not be construed as any limitation on the scope of protection of the present invention. The description of the preferred embodiments involves combinations of features, which may exist independently or in combination. The present invention is not particularly limited to the preferred embodiments. The scope of the present invention is defined by the claims.

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A three-step thermal insulation enclosure system suitable for large cryogenic liquid tanks, characterized in that: include: Insulation board units, a plurality of insulation board units are fixed on the surface of the large cryogenic liquid tank in a horizontal and vertical array, each insulation board unit is integrally formed into a three-step structure that tapers away from the surface of the large cryogenic liquid tank, so that the step structures of the plurality of insulation board units spliced ​​together together constitute a low-position insulation layer, a middle-position insulation layer and a high-position insulation layer, wherein the low-position insulation layer is close to the surface of the large cryogenic liquid tank, the high-position insulation layer is away from the surface of the large cryogenic liquid tank, and the middle-position insulation layer is located between the low-position insulation layer and the high-position insulation layer; The buffer unit is arranged between the insulation layers of adjacent insulation board units, wherein the elasticity of the buffer units corresponding to the low insulation layer and the high insulation layer is greater than that of the buffer unit corresponding to the middle insulation layer; The fixing unit fixes each insulation board unit on the surface of the large cryogenic liquid tank.

2. The three-step thermal insulation enclosure system suitable for large cryogenic liquid tanks according to claim 1 is characterized in that: Between adjacent insulation board units of the low-position insulation layer, the buffer unit is a first buffer strip in a compressed state.

3. The three-step thermal insulation enclosure system suitable for large cryogenic liquid tanks according to claim 2 is characterized in that: Among the mutually orthogonal first buffer strips, the first buffer strips in one direction extend throughout, and the first buffer strips in the other direction intermittently abut against the side surfaces of the first buffer strips in the one direction.

4. The three-step thermal insulation enclosure system suitable for large cryogenic liquid tanks according to claim 3 is characterized in that: Between adjacent insulation board units of the high-level insulation layer, the buffer unit is a third buffer strip. Among the mutually orthogonal third buffer strips, the third buffer strips in one direction extend throughout, and the third buffer strips in the other direction intermittently abut against the side surfaces of the third buffer strips in one direction.

5. The three-step thermal insulation enclosure system for large cryogenic liquid tanks according to any one of claim 4, characterized in that: Between adjacent insulation board units of the median insulation layer, the buffer unit is a second buffer strip and a buffer block. In the mutually orthogonal second buffer strips, the second buffer strips in two directions are jointly abutted against the side surface of the buffer block.

6. The three-step thermal insulation enclosure system for large cryogenic liquid tanks according to claim 5 is characterized in that: The second buffer strip is provided with a buffer base strip, and an elastic groove is opened in the buffer base strip, so that the second buffer strip can be elastically deformed in the horizontal direction; Alternatively, the second buffer strip is provided with a buffer base strip, and elastic strips are provided on both sides of the buffer base strip, so that the second buffer strip can be elastically deformed in the horizontal direction.

7. The three-step thermal insulation enclosure system for large cryogenic liquid tanks according to claim 1 is characterized in that: Between the insulation layers of adjacent insulation units, a sealing layer is adhered on the surface of the corresponding step structure.

8. The three-step thermal insulation enclosure system for large cryogenic liquid tanks according to claim 1 is characterized in that: The fixing unit is configured as a connecting column, and the insulation plate unit is formed with a through hole that penetrates the thickness of the plate. The connecting column penetrates the insulation plate unit through the through hole, and both ends of the connecting column are respectively fixed to the surface of the large cryogenic liquid tank and the end piece, wherein the through hole forms a step hole at the end away from the surface of the large cryogenic liquid tank, and a baffle and a sealing insulation block are sequentially arranged in the step hole.

9. The three-step thermal insulation enclosure system for large cryogenic liquid tanks according to claim 6, characterized in that: The first buffer strip is glass wool or elastic felt compressed at a compression rate of 2.5-3.8 times, wherein the resilience coefficient K of the elastic felt is not less than 44%, and the thermal conductivity is not higher than 0.04W / (m·K); Or, the buffer base strip of the second buffer strip and the thermal insulation board unit are made of the same material.

10. The three-step thermal insulation enclosure system for large cryogenic liquid tanks according to claim 6, characterized in that: The buffer base strip of the second buffer strip is made of glass fiber reinforced polyurethane material, and the thermal insulation board unit is made of polyurethane material.

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