Heat insulation, cold insulation and heat preservation structure for TYPE B low-temperature storage tank

Abstract

The invention relates to a thermal insulation and cold insulation structure for a TYPE B low-temperature storage tank, and relates to the field of ship storage tank thermal insulation technology, the thermal insulation and cold insulation structure comprises prefabricated plates, an elastic thermal insulation layer is arranged between any two adjacent prefabricated plates, the top of the elastic thermal insulation layer is higher than the top surface of the prefabricated plate, and a watertight layer is pasted on the top surface of the prefabricated plate. The watertight layers extend to the surfaces of the adjacent prefabricated slabs, and the watertight layers cover the tops of the elastic heat preservation layers; a plurality of polyurethane layers are sprayed on the surface of the watertight layer, an anti-cracking layer is arranged between any two adjacent polyurethane layers, and a mechanical protection layer is arranged on the surface of the polyurethane layer on the outermost side; a plurality of welding studs are fixed on the surface of the storage tank in advance; through holes allowing the welding studs to penetrate through are correspondingly formed in the surfaces of the prefabricated plates, and first connecting structures, second connecting structures or third connecting structures are installed on the welding studs.

Description

Technical Field

[0001] This application relates to the field of marine storage tank insulation technology, and in particular to a thermal insulation and cold preservation structure for TYPE B cryogenic storage tanks. Background Technology

[0002] In the shipping industry, cryogenic storage tanks are mainly used to store cryogenic fuels or liquid cargoes such as LNG (liquefied natural gas). Their classification is primarily based on the structural characteristics and volume adaptation scenarios of the cargo tanks / storage units. They can be broadly categorized into three main types, plus a category of small-scale, scenario-specific tanks. The insulation methods for each type of tank are deeply matched to its structural design and application requirements. Specific classifications and corresponding insulation methods are as follows: Membrane-type storage tanks: These tanks are integrated designs where the hull is the storage tank. They rely on two layers of cryogenic membranes as a barrier for the liquid cargo, while the hull bears the load. They are commonly found in very large LNG carriers. The core representatives are GTT's MARK Ⅲ and NO.96 series. They have a sophisticated insulation design, are expensive, have limited load capacity, and are difficult to repair.

[0003] Independent tank type: The tank is completely independent of the ship's hull structure, bearing the entire load of the liquid cargo itself, with the hull only providing support. This type is further subdivided into Moss type, B type, and C type. New Moss type tanks are rarely manufactured on the market now; the mainstream are B type and C type tanks. Their insulation methods are mainly divided into plate insulation and spray insulation. While plate insulation design is relatively superior, its complex tank shape leads to higher design, production, and installation costs. Spray insulation, while having less design cost, is prone to cracking and peeling due to the inherent properties of polyurethane, despite its low-temperature resistance. Summary of the Invention

[0004] In order to combine the advantages of plate insulation and sprayed insulation and improve the thermal insulation and cold insulation performance of the insulation structure, this application provides a thermal insulation and cold insulation structure for TYPE B cryogenic storage tanks.

[0005] The thermal insulation and cold preservation structure for TYPE B cryogenic storage tanks provided in this application adopts the following technical solution: A thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank includes prefabricated slabs fixed to the surface of the storage tank. An elastic insulation layer is provided between any two adjacent prefabricated slabs. The top of the elastic insulation layer is higher than the top surface of the prefabricated slab. A watertight layer is adhered to the top surface of the prefabricated slab. The watertight layer extends to the surface of the adjacent prefabricated slab and covers the top of the elastic insulation layer. The surface of the watertight layer is coated with several polyurethane layers, and a crack-resistant layer is provided between any two adjacent polyurethane layers. A mechanical protective layer is provided on the surface of the outermost polyurethane layer. The surface of the storage tank is pre-fixed with a number of welding studs, which are evenly distributed within the area covered by the precast slab. The surface of the storage tank is pre-fixed with a number of polystyrene gaskets, which are coaxially arranged on the outside of the welding studs and located between the precast slab and the tank surface of the storage tank. The surface of the precast slab is provided with through holes for welding studs to pass through. The welding studs are equipped with a first connecting structure, a second connecting structure or a third connecting structure. The first connecting structure is used to fix the precast slab. The second connecting structure is used to fix the precast slab and one or more polyurethane layers at the same time. The third connecting structure is used to fix the precast slab and limit the thickness of the polyurethane layer. The through holes are all filled with polyurethane.

[0006] By adopting the above technical solution, during actual construction, operators can pre-install welding studs and polystyrene gaskets on the tank surface according to the coverage area of ​​the precast slab, ensuring the welding studs are evenly distributed within the coverage area of ​​the precast slab. Subsequently, operators can adhere a watertight layer to the surface of the precast slab, extending the edge of the watertight layer beyond the edge of the precast slab. After placing an elastic insulation layer between the precast slab and adjacent slabs, operators can cover the portion of the watertight layer extending beyond the edge of the precast slab with low-temperature insulation material and then adhere it to the surface of the adjacent precast slab. The watertight layer adhered to the surface of the precast slab enhances its insulation properties. Effects: Because the top of the elastic insulation layer is higher than the top surface of the precast slab, and the elastic insulation layer deforms reversibly under stress, the watertight layer protruding from the edge of the precast slab and covering the surface of the elastic insulation layer can always be in a loose state. This design can absorb the deformation caused by the thermal expansion and contraction of the storage tank, protecting the watertight layer and the precast slab from damage. After the precast slab is placed in the corresponding area on the surface of the storage tank, the operator can fix the precast slab through the first connection structure, the second connection structure and the third connection structure, and fill the through holes with polyurethane. The polyurethane filled in the through holes can ensure the insulation performance at the through holes. After filling the through-holes with polyurethane, operators can spray multiple layers of polyurethane onto the surface of the precast slab, adding a crack-resistant layer between adjacent layers. This crack-resistant layer strengthens the fixation and reduces heat loss caused by cracks due to thermal expansion and contraction or external impacts. When spraying polyurethane onto the precast slab, a second connecting structure can be used to fix one or more layers, further reinforcing the polyurethane coating. A third connecting structure provides a reference point for operators, facilitating control of the top polyurethane layer thickness and eliminating the need for traditional probe-based thickness measurements, thus saving repair time. The combined use of the precast slab and the sprayed polyurethane creates an insulation structure that combines the advantages of both panel insulation and sprayed insulation, making it suitable for complex tank surfaces and offering benefits such as low-temperature resistance, crack resistance, and durability.

[0007] Preferably, the top of the precast slab is provided with a plurality of countersunk holes, which are respectively provided on the top of the through holes; The end of each welding stud away from the storage tank is threadedly connected to a threaded sleeve. The first connection structure includes a first connecting rod, the second connection structure includes a second connecting rod, and the third connection structure includes a third connecting rod. The bottom ends of the first connecting rod, the second connecting rod, and the third connecting rod are respectively threadedly connected to the threaded sleeve. The first link, the second link and the third link are all equipped with a precast slab fixing mechanism for fixing the precast slab. The precast slab fixing mechanism is located in the countersunk hole. The second link is also equipped with a polyurethane layer fixing mechanism for fixing one or more polyurethane layers. The third link is also equipped with a thickness limiting bar for limiting the thickness of the polyurethane layer. The countersunk holes are all filled with polyurethane.

[0008] By adopting the above technical solution, the precast slab can be fixed to the surface of the tank body of the storage tank through the precast slab fixing mechanism on the first link, the second link and the third link; the polyurethane layer fixing mechanism on the second link can strengthen and fix one or more polyurethane layers on the surface of the precast slab; and the thickness limiting bar installed on the third link can facilitate the operator to control the thickness of the polyurethane layer with the thickness limiting bar as a reference.

[0009] Preferably, the precast panel fixing mechanism includes a wooden fixing layer and an ultra-thin fixing plate. The wooden fixing layer is located at the bottom of the countersunk hole, and a first through hole is provided through the middle of the wooden fixing layer. The radius of the first through hole is smaller than the radius of the through hole, and the radius of the first through hole is larger than the radius of the first connecting rod, the second connecting rod, and the third connecting rod. The ultra-thin fixing plate has a second through hole in the middle that is adapted to the first connecting rod, the second connecting rod or the third connecting rod. The ends of the first connecting rod, the second connecting rod and the third connecting rod that pass through the second through hole are all threaded with a first nut. The ultra-thin fixing plate and the wooden fixing layer are pressed against the first nut and the bottom inner wall of the countersunk hole. The ultra-thin fixing plate is also provided with several injection holes for polyurethane injection. The injection holes are all located between the inner circle of the first through hole and the outer circle of the second through hole, and the injection holes are evenly arranged in a circumferential array on the periphery of the second through hole.

[0010] By adopting the above technical solution, the wooden fixing layer and the ultra-thin fixing plate can be limited by the first nut, and the precast slab can be fixed by the wooden fixing layer located at the bottom of the countersunk hole, so that the precast slab is attached to the surface of the tank body. The countersunk hole design can prevent the first nut, washer, wooden fixing layer and ultra-thin fixing plate from protruding from the surface of the precast slab; the polyurethane filled in the countersunk hole can further ensure the thermal insulation performance of the precast slab; the injection hole on the ultra-thin fixing plate can facilitate the operator to inject and fill the polyurethane into the through hole.

[0011] Preferably, a connecting groove is provided between the injection hole and the second through-rod hole, and the connecting groove is formed through the ultra-thin fixing plate.

[0012] By adopting the above technical solution, the connecting groove on the ultra-thin fixing plate allows the middle part of the ultra-thin fixing plate to deform and release stress when the stress is too high at a certain point in the precast slab, thus protecting the precast slab from damage.

[0013] Preferably, the length of the second link is greater than that of the first link, and the top of the second link penetrates one or more polyurethane layers; The polyurethane layer fixing mechanism includes a pad, a third through hole for the second connecting rod to pass through in the middle of the pad, a second nut being threaded to the end of the second connecting rod that passes through the polyurethane layer, and the pad being pressed against the second nut between the polyurethane layer.

[0014] By adopting the above technical solution, the top of the polyurethane layer can be reinforced and fixed through the second nut and the washer, which can reduce the occurrence of polyurethane layer falling off.

[0015] Preferably, the length of the third link is the same as the length of the first link, and the end of the third link away from the tank body is threadedly connected to a thickness limiting rod. The thickness limiting rod is threadedly connected to the top end of the third link, and the top end of the thickness limiting rod extends into the top layer of polyurethane.

[0016] By adopting the above technical solution, the operator can use the thickness limiting rod as a reference during the spraying of the polyurethane layer. This allows for control of the thickness and surface flatness of the polyurethane layer without the need for a probe, and also saves the time required for later repairs caused by probe thickness measurement.

[0017] Preferably, the precast panel is made of polyurethane, polyisocyanurate, or polystyrene.

[0018] Preferably, the watertight layer is a dense aluminum foil cloth coated with a waterproof layer, and the watertight layer is adhered to the top surface of the precast slab with low-temperature adhesive.

[0019] Preferably, the mechanical protective layer is a coating layer.

[0020] Preferably, the crack-resistant layer is a glass fiber mesh.

[0021] In summary, the thermal insulation and cold preservation structure for TYPE B cryogenic storage tanks proposed in this application has at least one of the following beneficial technical effects: 1. This application uses a combination of prefabricated panels and sprayed polyurethane to form the insulation structure of the storage tank, which can make the insulation structure combine the advantages of panel insulation and sprayed insulation. It is suitable for complex tank surfaces and also has the advantages of low temperature resistance, crack resistance, and non-detachment. 2. Since the top of the elastic insulation layer is higher than the top surface of the precast slab, and the elastic insulation layer deforms reversibly after being stressed, the watertight layer that protrudes from the edge of the precast slab and covers the surface of the elastic insulation layer can always be in a loose state. This design can absorb the deformation of the storage tank due to thermal expansion and contraction, and protect the watertight layer and the precast slab from damage. 3. The multi-layer polyurethane coating on the surface of the precast panel can further enhance the thermal insulation performance of the insulation structure. The crack-resistant layer between the polyurethane layers can strengthen the fixation and reduce heat loss caused by cracks caused by thermal expansion and contraction of the polyurethane layer or external impact. 4. The polyurethane layer fixing mechanism can reinforce and fix one or more polyurethane layers, which can reduce the occurrence of polyurethane layer detachment; 5. With the thickness gauge, the operator can use the thickness gauge as a reference during the spraying of the polyurethane layer. This allows the operator to control the thickness and surface flatness of the polyurethane layer without the need for a probe, and also saves the time required for later repairs caused by probe thickness measurement. 6. The injection holes on the ultra-thin fixing plate allow operators to easily inject and fill polyurethane into the through holes; the connecting grooves on the ultra-thin fixing plate allow for deformation of the middle part of the ultra-thin fixing plate to release stress when the stress is too high at a certain point in the precast slab, thus protecting the precast slab from damage. Attached Figure Description

[0022] Figure 1 This is a schematic diagram illustrating the overall structure of the thermal insulation structure in an embodiment of this application.

[0023] Figure 2 This application embodiment is used to illustrate the schematic diagram of the installation position of the elastic insulation layer around the precast slab.

[0024] Figure 3 yes Figure 1 The enlarged schematic diagram of section A is mainly used to show the overall structure of the precast slab fixing mechanism.

[0025] Figure 4 This is a schematic diagram illustrating the overall structure of the ultra-thin fixing sheet in an embodiment of this application.

[0026] Explanation of reference numerals in the attached drawings: 1. Precast slab; 101. Through hole; 102. Countersunk hole; 2. Elastic insulation layer; 3. Watertight layer; 4. Polyurethane; 5. Crack-resistant layer; 6. Mechanical protection layer; 7. Polystyrene gasket; 8. Tank body; 9. Welding stud; 10. First connecting rod; 11. Second connecting rod; 12. Third connecting rod; 13. Wooden fixing layer; 131. First through-rod hole; 14. Ultra-thin fixing piece; 141. Second through-rod hole; 142. Injection hole; 143. Connecting groove; 15. Round washer; 16. First nut; 17. Washer plate; 18. Second nut; 19. Thickness limiting rod; 20. Polyurethane layer. Detailed Implementation

[0027] The following combination Figures 1-4 This application will be described in further detail.

[0028] Example This application discloses an insulation and cold-preservation structure for a TYPE B cryogenic storage tank. (Refer to...) Figure 1 and Figure 2 It mainly includes a precast slab 1 fixed to the surface of the tank body 8 of the storage tank. An elastic insulation layer 2 is provided between adjacent sides of the precast slab 1, and the top of the elastic insulation layer 2 is higher than the top surface of the precast slab 1.

[0029] A watertight layer 3 is attached to the top surface of the precast slab 1 with low-temperature adhesive. The sides of the watertight layer 3 extend beyond the sides of the precast slab 1. The portion of the watertight layer 3 extending beyond the sides of the precast slab 1 extends to the surface of the adjacent precast slab 1 or other materials and is fixed to the surface of the adjacent precast slab 1 or other materials with low-temperature adhesive. The watertight layer 3 covers the top surface of the elastic insulation layer 2.

[0030] It should be noted that in this embodiment, the precast panel 1 is made of polyurethane, polyisocyanurate, or polystyrene, which has good thermal insulation and cold insulation properties. The watertight layer 3 is made of dense aluminum foil cloth coated with a waterproof layer. The dense aluminum foil cloth can further improve the thermal insulation performance of the precast panel 1, and the waterproof layer on the surface of the dense aluminum foil cloth can improve the waterproof performance of the precast panel 1. In some other embodiments, other materials for the precast panel 1 and watertight layer 3 can be selected according to the actual needs of use, which will not be limited or described in detail here.

[0031] A number of through holes 101 are evenly provided on the precast slab 1, and a countersunk hole 102 coaxial with the through hole 101 is provided at the top of each through hole 101. The through holes 101 and the countersunk holes 102 make it easy for operators to fix the precast slab 1 to the surface of the tank body 8 of the storage tank.

[0032] In this embodiment, the insulation structure also includes three polyurethane layers 4 sprayed onto the surface of the watertight layer 3. A crack-resistant layer 5 (glass-restricting mesh fabric is used in this embodiment) is provided between any two adjacent polyurethane layers 4, and a mechanical protective layer 6 (a coating layer sprayed onto the surface of the outermost polyurethane layer 4 is used in this embodiment) is provided on the surface of the outermost polyurethane layer 4. In some other embodiments, the number of polyurethane layers 4 can be increased or decreased according to actual usage needs; this is not limited or elaborated upon here.

[0033] When installing the precast slab 1, the operator pre-installs welding studs 9 on the surface of the tank body 8 of the storage tank. The welding studs 9 are evenly distributed within the coverage area of ​​the precast slab 1, and each welding stud 9 corresponds to a through hole 101. Before fixing the precast slab 1 to the surface of the tank body 8 of the storage tank, the operator can pre-fix a polystyrene gasket 7 at the outer circle position of each welding stud 9.

[0034] The operator aligns the through-hole 101 on the precast slab 1 with the position of the welding stud 9, places the precast slab 1 in the corresponding area, and then installs a first connecting structure, a second connecting structure, or a third connecting structure on the welding stud 9 according to design requirements. The first connecting structure is used to fix the precast slab 1, the second connecting structure is used to simultaneously fix the precast slab 1 and one or more polyurethane layers 4, and the third connecting structure is used to fix the precast slab 1 and limit the thickness positioning of the polyurethane layer 4. Furthermore, in this embodiment, after the precast slab 1 is fixed to the surface of the tank body 8 of the storage tank, the operator fills the through-hole 101 and countersunk hole 102 with polyurethane, which ensures the thermal insulation and cold preservation effect of the through-hole 101 and countersunk hole 102 areas.

[0035] In this embodiment, the ends of the welding studs 9 furthest from the storage tank are all threaded with threaded sleeves. (Refer to...) Figure 1 The first connecting structure includes a first connecting rod 10, the second connecting structure includes a second connecting rod 11, and the third connecting structure includes a third connecting rod 12. The bottom ends of the first connecting rod 10, the second connecting rod 11, and the third connecting rod 12 are all threadedly connected to the threaded sleeves, and the first connecting rod 10, the second connecting rod 11, and the third connecting rod 12 are all equipped with a precast slab fixing mechanism for fixing the precast slab 1.

[0036] Reference Figure 1 and Figure 3The precast slab fixing mechanisms are all located within the countersunk holes 102, and each mechanism includes a wooden fixing layer 13 and an ultra-thin fixing plate 14. The wooden fixing layer 13 is located at the bottom of the countersunk hole 102, and a first through-hole 131 is provided through the middle of the wooden fixing layer 13. The radius of the first through-hole 131 is smaller than the radius of the through hole 101, and the radius of the first through-hole 131 is larger than the radii of the first connecting rod 10, the second connecting rod 11, and the third connecting rod 12. The ultra-thin fixing plate 14 is coaxially sleeved on the first connecting rod 10, the second connecting rod 11, or the third connecting rod 12, and is located within the wooden fixing layer 102. Above 3, a second through hole 141 adapted to the first connecting rod 10, the second connecting rod 11 or the third connecting rod 12 is opened through the middle of the ultra-thin fixing plate 14; a first nut 16 is threaded to one end of the first connecting rod 10, the second connecting rod 11 or the third connecting rod 12 passing through the second through hole 141; a round washer 15 is coaxially sleeved on the first connecting rod 10, the second connecting rod 11 and the third connecting rod 12; the round washer 15 is located between the first nut 16 and the ultra-thin fixing plate 14; the round washer 15, the wooden fixing layer 13 and the ultra-thin fixing plate 14 are all pressed against the first nut 16 and the bottom inner wall of the countersunk hole 102.

[0037] The precast slab 1 can be fixed to the surface of the tank body 8 of the storage tank by means of the wooden fixing layer 13 and the ultra-thin fixing plate 14. Since the precast slab 1 has through holes 101 and countersunk holes 102, the precast slab 1 can be fixed by the precast slab fixing mechanism in the event of a certain positional deviation or height difference, which can improve the fault tolerance rate of the insulation structure installation.

[0038] Furthermore, since the precast panel fixing mechanism is located inside the countersunk hole 102, the first nut 16, washer, wooden fixing layer 13 and ultra-thin fixing piece 14 are not required to protrude from the surface of the precast panel 1, which can improve the flatness of the surface of the precast panel 1.

[0039] In this embodiment, to facilitate the filling of polyurethane into the through hole 101, four injection holes 142 are provided through the ultra-thin fixing plate. The four injection holes 142 are evenly arranged in a circumferential array on the periphery of the second through hole 141, and all four injection holes 142 are located between the inner circle of the first through hole 131 and the outer circle of the second through hole 141. The arrangement of multiple injection holes 142 can facilitate the uniform filling of polyurethane into the through hole 101. In some other embodiments, the number of injection holes 142 can be adjusted according to the diameter of the through hole 101, which is not limited or described in detail here.

[0040] Please refer to Figure 4 In order to release stress by deforming the middle of the ultra-thin fixing piece 14 when the stress is too high at a certain point in the precast slab 1, and to protect the precast slab 1 from damage, in this embodiment, a connecting groove 143 is connected between the injection hole 142 and the second through hole 141 in the middle, and the connecting groove 143 is opened through the ultra-thin fixing piece 14.

[0041] In this embodiment, the length of the second connecting rod 11 is greater than the length of the first connecting rod 10. The top end of the second connecting rod 11 extends to the top surface of the first polyurethane layer 4, and a polyurethane layer fixing mechanism for fixing the first polyurethane layer 4 is installed on the second connecting rod 11. The polyurethane layer fixing mechanism includes a washer 17 coaxially mounted on the end of the second connecting rod 11. A second nut 18 is threadedly connected to the end of the second connecting rod 11 that penetrates the first polyurethane layer. The washer 17 abuts against the second nut 18 and the crack-resistant layer 5 on the top surface of the first polyurethane layer 4.

[0042] The second nut 18, used in conjunction with the washer 17, can reinforce and fix the first polyurethane layer 4, reducing the likelihood of it detaching. In some other embodiments, the length of the second connecting rod 11 can be extended to reinforce and fix the second or third polyurethane layer 4; this is not limited or elaborated upon here.

[0043] In this embodiment, the length of the third link 12 is the same as the length of the first link 10. The top of the third link 12 is threadedly connected to a thickness limiting rod 19. The top of the thickness limiting rod 19 is lower than the top surface of the outermost polyurethane layer 4 and higher than the bottom surface of the outermost polyurethane layer 4.

[0044] With the thickness gauge 19, the operator can use the thickness gauge 19 as a reference during the spraying of polyurethane layer 4, and can control the thickness and surface flatness of polyurethane layer 4 without the need to use a probe, which also saves the time of subsequent repair caused by probe thickness measurement.

[0045] In some other embodiments, the thickness limiting rod 19 of corresponding length can be selected according to the thickness of each polyurethane layer 4 and the number of polyurethane layers 4, which will not be limited or described in detail here.

[0046] In this embodiment, the insulation structure of the storage tank is formed by combining the prefabricated panel 1 and the sprayed polyurethane. This allows the insulation structure to combine the advantages of panel insulation and sprayed insulation, making it suitable for tanks with complex surfaces. It also has the advantages of low temperature resistance, resistance to cracking, and resistance to detachment.

[0047] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank, characterized in that, The container includes a precast slab (1) fixed to the surface of the storage tank. An elastic insulation layer (2) is provided between any two adjacent precast slabs (1). The top of the elastic insulation layer (2) is higher than the top surface of the precast slab (1). A watertight layer (3) is pasted on the top surface of the precast slab (1). The watertight layer (3) extends to the surface of the adjacent precast slab (1) and covers the top of the elastic insulation layer (2). The surface of the watertight layer (3) is coated with several polyurethane layers (4), and a crack-resistant layer (5) is provided between any two adjacent polyurethane layers (4). A mechanical protective layer (6) is provided on the surface of the outermost polyurethane layer (4). The surface of the storage tank is pre-fixed with a number of welding studs (9), which are evenly distributed in the area covered by the precast plate (1). The surface of the storage tank is pre-fixed with a number of polystyrene gaskets (7), which are coaxially arranged on the outside of the welding studs (9). The polystyrene gaskets (7) are located between the precast plate (1) and the surface of the tank body (8). The surface of the precast slab (1) is provided with through holes (101) for the welding studs (9) to pass through. The welding studs (9) are equipped with a first connection structure, a second connection structure or a third connection structure. The first connection structure is used to fix the precast slab (1). The second connection structure is used to fix the precast slab (1) and one or more polyurethane layers (4) at the same time. The third connection structure is used to fix the precast slab (1) and limit the thickness of the polyurethane layer (4). The through holes (101) are all filled with polyurethane.

2. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 1, characterized in that, The top of the precast slab (1) is provided with a plurality of countersunk holes (102), and the countersunk holes (102) are respectively provided on the top of the through holes (101); The welding stud (9) is threaded with a sleeve at the end away from the storage tank. The first connection structure includes a first connecting rod (10), the second connection structure includes a second connecting rod (11), and the third connection structure includes a third connecting rod (12). The bottom ends of the first connecting rod (10), the second connecting rod (11), and the third connecting rod (12) are threadedly connected to the sleeves respectively. The first link (10), the second link (11) and the third link (12) are all equipped with a precast slab fixing mechanism for fixing the precast slab (1). The precast slab fixing mechanism is located in the countersunk hole (102). The second link (11) is also equipped with a polyurethane layer fixing mechanism for fixing one or more polyurethane layers (4). The third link (12) is also equipped with a thickness limiting rod (19) for limiting the thickness of the polyurethane layer (4). The countersunk holes (102) are all filled with polyurethane.

3. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 2, characterized in that, The precast panel fixing mechanism includes a wooden fixing layer (13) and an ultra-thin fixing plate (14). The wooden fixing layer (13) is located at the bottom of the countersunk hole (102), and a first through hole (131) is provided through the middle of the wooden fixing layer (13). The radius of the first through hole (131) is smaller than the radius of the through hole (101), and the radius of the first through hole (131) is larger than the radius of the first connecting rod (10), the second connecting rod (11), and the third connecting rod (12). The ultra-thin fixing plate (14) has a second through hole (141) through its middle part, which is adapted to the first connecting rod (10), the second connecting rod (11) or the third connecting rod (12). The ends of the first connecting rod (10), the second connecting rod (11) and the third connecting rod (12) passing through the second through hole (141) are all threaded with a first nut (16). The ultra-thin fixing plate (14) and the wooden fixing layer (13) are pressed against the first nut (16) and the bottom inner wall of the countersunk hole (102). The ultra-thin fixing plate (14) is also provided with a number of injection holes (142) for polyurethane injection. The injection holes (142) are all located between the inner circle of the first through hole (131) and the outer circle of the second through hole (141), and the number of injection holes (142) are evenly arranged in a circumferential array on the periphery of the second through hole (141).

4. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 3, characterized in that, A connecting groove (143) is connected between the injection hole (142) and the second through hole (141), and the connecting groove (143) is opened through the ultra-thin fixing plate (14).

5. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 4, characterized in that, The length of the second link (11) is greater than that of the first link (10), and the top of the second link (11) penetrates one or more polyurethane layers (4). The polyurethane layer fixing mechanism includes a pad (17), a third through hole for the second connecting rod (11) to pass through the middle of the pad (17), and a second nut (18) threadedly connected to the end of the second connecting rod (11) that passes through the polyurethane layer (4). The pad (17) is pressed against the second nut (18) and the polyurethane layer (4).

6. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 4, characterized in that, The length of the third link (12) is the same as that of the first link (10). The end of the third link (12) away from the tank body (8) is threadedly connected to a thickness-limiting rod (19). The thickness-limiting rod (19) is threadedly connected to the top end of the third link (12). The top end of the thickness-limiting rod (19) extends into the top layer of polyurethane (4).

7. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 1, characterized in that, The material of the precast panel (1) is polyurethane, polyisocyanurate or polystyrene.

8. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 1, characterized in that, The watertight layer (3) is a dense aluminum foil cloth coated with a waterproof layer, and the watertight layer (3) is pasted on the top surface of the precast plate (1) with low temperature adhesive.

9. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 1, characterized in that, The mechanical protective layer (6) is a coating layer.

10. The thermal insulation and cold preservation structure for a TYPE B cryogenic storage tank according to claim 1, characterized in that, The crack-resistant layer (5) is a glass limiting mesh fabric.

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