Insulation board structure for liquefied gas carrier cryogenic tank and production, installation and application thereof

Abstract

This invention discloses an insulation plate structure for cryogenic storage tanks of liquefied gas carriers, as well as its production, installation, and application. The structure includes multiple insulating foam blocks laid on the tank surface, with expansion gaps reserved between adjacent foam blocks. A U-shaped fixing frame welded to the tank body is installed within the gap, with its top pressing against the foam blocks on both sides, combining adjacent insulating plates together and fixing them to the tank surface. The gaps are filled with an elastic filler that can adapt to deformation. A joint plug with a compression reset groove is provided above the U-shaped frame and fixed by adhesive. The U-shaped fixing frame comes in two forms: an internally threaded sleeve type and an externally threaded connecting sleeve type. It is manufactured through PUF or EPS foaming, cutting, NDT testing, and multi-layer composite processing. Installation is achieved through mechanical compression, elastic filling, and sealing with butyl tape or TPO hot welding. This invention is applicable to LNG, ethane, and other liquefied gas carrier storage tanks, effectively resisting thermal expansion and contraction at temperatures ranging from -163℃ to room temperature, preventing cracking and cold bridging, and achieving a highly reliable domestically produced enclosure system.

Description

Technical Field

[0001] This invention belongs to the field of cryogenic insulation technology, specifically relating to an insulating plate structure for liquefied gas (LNG) ship tanks or storage tanks, particularly suitable for cryogenic transportation or storage scenarios involving LNG (liquefied natural gas), LEG (liquefied ethylene / ethane), LPG (liquefied petroleum gas), and LAC (liquid ammonia). Furthermore, this invention also relates to the manufacturing method of this insulating plate structure, its construction and installation process, and its specific application in marine cryogenic storage and transportation equipment. Background Technology

[0002] The cargo tanks of liquefied gas carriers need to operate stably for extended periods at temperatures ranging from -40°C to -163°C or even lower, placing extremely high demands on the sealing performance, structural strength, and adaptability to thermal expansion and contraction of the insulation system. Currently, mainstream containment systems (such as GTTNO96 and MARK III) suffer from high costs and uncontrollable supply chains. Therefore, it is necessary to develop domestically produced insulation board systems with independent intellectual property rights that meet ultra-low temperature operating conditions and possess reliable crack resistance and sealing performance.

[0003] Traditional insulation boards often use a single piece of foam directly glued together, failing to adequately account for material shrinkage caused by extreme temperature differences (which can reach several millimeters per meter). This easily leads to gaps at the joints, resulting in cold bridging, frost formation, and even structural failure. Furthermore, existing fixing methods rely heavily on adhesives, lacking mechanical anchoring, making them prone to detachment under vibration, impact, or long-term service. Therefore, there is an urgent need for an integrated insulation board structure that combines mechanical compression, elastic compensation, and multi-layer sealing functions. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a liquefied gas marine insulation plate system with reliable structure, adaptability to ultra-low temperature thermal expansion and contraction, and multiple sealing protections, along with a complete manufacturing and installation method, to achieve domestic substitution.

[0005] To achieve the above objectives, the present invention provides the following technical solution: In one aspect, an insulating slab is provided for cryogenic storage tanks on liquefied gas carriers.

[0006] The structure includes: multiple insulating foam blocks made of PUF (polyurethane foam) or EPS (expandable polystyrene foam), laid on the surface of the tank at predetermined positions; Expansion gaps are reserved between adjacent insulating blocks to accommodate dimensional deformation caused by temperature changes; A U-shaped fixing frame is installed in the expansion joint, with its bottom welded to the tank body and its top pressing down on the insulating bubbles on both sides to achieve mechanical anchoring. The gaps are filled with elastic fillers (such as EVA / PE flexible foam, melamine foam or other flexible materials) that can adapt to the expansion and contraction of the foam block to prevent cold bridging. The U-shaped fixing frame is equipped with a joint plug above it, which has multiple vertical extrusion reset grooves. It is bonded to the insulating bubble and the metal fasteners of the U-shaped part by applying glue, and has both sealing and buffering functions.

[0007] There are two implementation methods for the U-shaped fixing bracket: Type 1: Employs arc-welded bolt sleeves, first screws, and U-shaped metal fasteners, resulting in a compact structure but with non-adjustable height; Type 2: It adopts arc-welded screws, screw connecting sleeves, and U-shaped metal fasteners. The clamping height can be adjusted through the connecting sleeve to adapt to uneven tank surfaces.

[0008] Secondly, a method for manufacturing the aforementioned insulating board structure is provided.

[0009] The method includes steps such as PUF polyurethane or EPS foaming, automatic cutting, curing, non-destructive testing (NDT), multi-layer composite (including stainless steel wire mesh reinforcement), stainless steel plate or aluminum plate or galvanized steel plate or GRP (fiberglass plate) or TPO outer protective layer lamination, pressing and shaping, and MES digital traceability, to ensure product consistency and quality control.

[0010] PUF polyurethane foam or EPS foam is cut and processed to produce products of different thicknesses and lengths; then stainless steel plates, aluminum plates, galvanized steel plates, GRP (fiberglass plates), TPO and butyl tape are set on the surface of the insulation board; the seams between the boards are mainly made of flexible materials such as melamine cotton and glass wool; the seams between the boards are mainly made of polyurethane, EPS and expansion modules made of flexible foam.

[0011] Thirdly, the construction and installation methods for the above-mentioned insulation board structure are provided.

[0012] This includes marking the tank body, welding anchors, laying insulating bubbles, filling with elastic fillers, installing joint plugs, laying aluminum foil mesh and butyl tape or TPO hot air welding seals, forming a complete system of mechanical fixing, elastic filling and multi-layer sealing.

[0013] Fourthly, the application of this insulation board structure in marine cryogenic storage and transportation equipment is provided.

[0014] It is suitable for LNG carriers, LNG fuel tanks, ethylene and ethane carriers (LEG), liquefied petroleum gas carriers (LPG), liquid ammonia carriers (LAC), and other scenarios. It can maintain long-term sealing and structural integrity under cyclic conditions from -40℃ to 163℃ to normal temperature.

[0015] Compared with existing technologies, the advantages of this invention are as follows: This invention effectively absorbs deformation caused by temperature changes from -200℃ to 40℃ by reserving expansion joints, using elastic fillers, and joint plugs with reset grooves, thus preventing plate cracking and exhibiting strong resistance to thermal expansion and contraction. In this invention, the U-shaped fixing frame provides mechanical clamping force, and the adhesive provides auxiliary bonding, significantly improving vibration and peel resistance, forming a double-fixing guarantee. This invention employs a multi-seal design: from the elastic filler, joint plugs, aluminum foil mesh, and TPO waterproof layer, a quadruple sealing barrier is formed to prevent cold bridging and moisture intrusion. This invention supports intelligent construction, achieving both domestic production and intelligentization. Attached Figure Description

[0016] The present invention will now be further described with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the structure of the present invention.

[0018] Figure 2 This is a schematic diagram of the U-shaped fixing frame in this invention.

[0019] Figure 3 This is a schematic diagram of the joint plug in this invention.

[0020] Figure 4 This is a schematic diagram of the structure of U-shaped fixing frame type 1 in this invention.

[0021] Figure 5 This is a schematic diagram of the structure of U-shaped fixing frame type 2 in this invention.

[0022] In the figure: 1 is an insulating bubble block, 2 is an expansion joint, 3 is a U-shaped fixing frame, 30 is a U-shaped metal fastener, 31 is a columnar groove, 301 is an arc-welded bolt sleeve, 302 is the first screw, 311 is an arc-welded screw, 312 is a screw connecting sleeve, 4 is an elastic filler, 5 is a joint plug, and 51 is a compression reset groove. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] Example 1: Structural Assembly As attached Figures 1 to 5 As shown in the figure, this embodiment provides an insulating slab for a cryogenic storage tank of an LPG carrier, comprising insulating bubble blocks 1. Multiple insulating bubble blocks 1 are laid on the surface of the tank body at preset positions. Expansion gaps 2 are reserved between adjacent insulating bubble blocks 1. A U-shaped fixing frame 3 is provided in the expansion gap 2. The bottom of the U-shaped fixing frame 3 is welded and fixed to the surface of the tank body. The top of the U-shaped fixing frame 3 presses down the adjacent insulating bubble blocks 1 on both sides of the expansion gap 2. The expansion joint 2 is provided with an elastic filler 4, which can adapt to the expansion and contraction of the insulating bubble 1.

[0025] Preferably, the structure of the U-shaped fixing frame 3 includes an arc-welded bolt sleeve 301, a first screw 302, and a U-shaped metal fastener 30. The arc-welded bolt sleeve 301 is a blind hole structure with an open top, and an internal thread is provided inside the blind hole. The bottom of the arc-welded bolt sleeve 301 is welded to the surface of the tank in the expansion joint 2. The bottom of the U-shaped plate of the U-shaped metal fastener 30 is pressed against the top of the arc-welded bolt sleeve 301. The U-shaped plates of the U-shaped metal fastener 30 extend horizontally on both sides and are matched and pressed against the adjacent insulating bubbles 1 on both sides of the expansion joint 2. The first screw 302 is provided with an external thread corresponding to the internal thread of the blind hole of the arc-welded bolt sleeve 301. The first screw 302 passes through the bottom of the U-shaped plate of the U-shaped metal fastener 30 and is matched and connected with the internal thread of the blind hole of the arc-welded bolt sleeve 301. The bolt head at the top of the first screw 302 is matched and pressed against the U-shaped plate of the U-shaped metal fastener 30.

[0026] Further, the structure of the U-shaped fixing bracket 3 includes an arc-welded screw 311, a screw connecting sleeve 312, and a U-shaped metal fastener 30; the arc-welded screw 311 is provided with external threads, the screw connecting sleeve 312 has an axially through-hole structure, the through-hole of the screw connecting sleeve 312 is provided with internal threads, the screw connecting sleeve 312 is movably threadedly connected to the arc-welded screw 311, the bottom of the arc-welded screw 311 is welded and fixed to the surface of the tank within the expansion joint 2, and the arc-welded screw 311... 11 is provided at the bottom of the U-shaped plate through the U-shaped metal fastener 30. The screw connecting sleeve 312 is located on the lower side of the U-shaped metal fastener 30. The U-shaped plate of the U-shaped metal fastener 30 extends horizontally on both sides and is matched and pressed against the adjacent insulating bubble blocks 1 on both sides of the expansion joint 2. The bolt head at the top of the arc welding screw 311 is matched and pressed against the U-shaped plate of the U-shaped metal fastener 30. The screw connecting sleeve 312 is movable and adjustable on the arc welding screw 311 and is pressed upward against the lower side of the U-shaped plate of the U-shaped metal fastener 30.

[0027] The U-shaped metal fastener 30 has a columnar groove 31 in the middle of the U-shaped plate corresponding to the bolt head, which matches the bolt head profile.

[0028] In this embodiment, a joint plug 5 is provided on the upper side of the U-shaped metal fastener 30. The joint plug 5 has multiple extrusion reset grooves 51 arranged in parallel in the vertical direction. The joint plug 5 is bonded and fixed to the U-shaped metal fastener 30 and the insulating bubble block 1 by applying adhesive.

[0029] Weld arc bolts (Type 2) onto the surface of the cryogenic storage tank. Lay prefabricated PUF or EPS insulating foam blocks 1 in place, aligning the expansion joint 2 with the bolts. Insert U-shaped metal fasteners 30, tighten the screw connecting sleeve 312 to press it upward against the bottom surface of the U-shaped plate, and press the bolt head against the columnar groove 31 at the top of the U-shaped plate. Embed EVA foam as elastic filler 4 into the gap 2, and then attach a melamine joint plug 5 with 5 extrusion reset grooves 51 on top.

[0030] Example 2: Manufacturing and Installation This embodiment describes a construction method for insulating slabs used in cryogenic storage tanks of liquefied gas carriers, comprising the following steps: S1. Production of PUF or EPS block foam; PUF or EPS block foam production: PUF or EPS block foam is produced by foaming large blocks of foam using specialized foaming equipment, with real-time monitoring of production process, temperature, and pressure parameters. S2. Bubble cutting; The large foam blocks, once foamed, move on a conveyor belt and are precisely cut into standard-sized blocks by an automated cutting device. The cut blocks are then neatly arranged on a roller conveyor. S3. Bubble curing / solidification; The cut blocks are automatically transported by a stacker crane to a racking system for storage and curing, completing the solidification process to achieve stable physical properties.

[0031] S4. Flat plate cutting; After curing, the bubble block is fed into a flatbed cutting machine, where it undergoes multiple cutting processes to be cut into flatbeds of uniform thickness. The cut flatbeds are then sorted and transported on a conveyor line. S5.NDT detection; The insulation board undergoes non-destructive testing equipment to check for internal defects using testing methods including ultrasonic testing, and the test data is displayed on the monitoring screen in real time. S6. External dimensions cutting; The qualified boards are precisely cut into the outline by a circular saw driven by a robotic arm, cutting the flat plate into insulation boards of the set size and shape; S7. Apply adhesive to the lower layer of foam; The cut lower foam board surface is coated with glue, and the robotic arm evenly applies glue to the board surface to form a striped glue layer. S8. Assemble the wire mesh; Stainless steel wire mesh is laid on the lower layer of foam board coated with adhesive, and the wire mesh completely covers the board surface; S9. Steel wire mesh coated with adhesive; Apply adhesive again to the wire mesh to form an adhesive layer to fix the wire mesh and bond the upper material. S10. Assemble the upper layer of foam; The upper foam board is assembled onto the wire mesh to form a sandwich structure.

[0032] S11. Top layer of foam coated with adhesive; Apply adhesive to the surface of the upper foam board to prepare for the subsequent laying of the outer protective layer; S12. Stainless steel sheet, aluminum sheet, galvanized steel sheet, GRP (fiberglass reinforced plastic) sheet, or TPO outer sheath assembly; After the adhesive is applied, a stainless steel plate, aluminum plate, galvanized steel plate, GRP (fiberglass plate), or TPO (thermoplastic polyolefin) outer sheath material is laid on the upper foam board, and the roll is unfolded to cover the entire board surface. S13. Pressing; The assembled multi-layer structure is fed into a laminating machine and laminated under pressure to ensure that the materials of each layer are tightly bonded. The surface of the finished laminated board is printed with markings and QR codes. S14.MES system; Showcase the Manufacturing Execution System (MES) interface, recording information throughout the product lifecycle: Product model, name, and dimensions; Inspection results, product quantity; Production date, warehousing time, and outbound time; S15. Packaging and Shipping; The finished insulation boards are stacked on pallets by a robotic arm for packaging and securing, and finally loaded onto trucks by forklifts for shipment.

[0033] This embodiment describes a construction and installation method for the insulating slab structure used in cryogenic storage tanks of liquefied gas carriers, comprising the following steps: S101. Installation of insulating boards; Marking lines on the surface of the tank; grid lines are drawn on the surface of the metal tank of the liquid cargo tank to mark the installation position of the insulation plate; S102. Welding bolts; Weld fixing bolts at the intersections of the marked grid to provide anchoring points for the subsequent installation of the insulation board; S103. Installation of insulation board; The prefabricated insulation boards are installed one by one onto the surface of the tank, and mechanically fixed with U-shaped clips and plugs to ensure that the insulation boards are tightly attached to the surface of the tank. S104. Aluminum foil mesh is used to cover the seams; After the insulation boards are installed, aluminum foil mesh is laid at the joints between the boards to form a continuous sealing layer. S105. Prefabricated module assembly at the joint; Prefabricated sealing modules consisting of EVA / PE modules and PUF and melamine foam are installed at the seams and assembled and fixed with glue. S106. Butyl tape or TPO sealant at the joints; Use butyl tape or a hot air welding gun to weld TPO (thermoplastic polyolefin) waterproof membrane to cover the joints, forming a complete waterproof sealing system; Insulation boards are produced according to the above process, and each board is bound with a unique QR code. On-site installation follows the above steps, with the seams successively covered with aluminum foil mesh, PUF or PES modules, EVA / PE sealing modules, and finally butyl tape or hot air welding gun to attach the TPO (thermoplastic polyolefin) waterproof membrane.

[0034] Example 3: Application Scenarios This embodiment demonstrates various marine application scenarios for this insulation system: The main cargo hold of an LNG carrier; LNG-powered fuel tank; LNG bunkering ship cargo tanks; LEG ethylene and ethane carrier cargo tanks; Liquefied petroleum gas (LPG) cargo tank; LAC liquid ammonia cargo hold; The insulating bubble 1 is mechanically fixed to the tank body by a U-shaped fixing frame 3. The expansion joint 2 is filled with elastic filler 4 and a joint plug 5 is provided to adapt to thermal expansion and contraction from -163℃ to room temperature, ensuring long-term sealing and structural integrity.

[0035] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An insulating slab for cryogenic storage tanks on liquefied gas carriers, comprising insulating bubbles (1), characterized in that, Multiple insulating bubbles (1) are laid on the surface of the tank at a preset position. Expansion gaps (2) are reserved between adjacent insulating bubbles (1). A U-shaped fixing frame (3) is provided in the expansion gap (2). The bottom of the U-shaped fixing frame (3) is welded and fixed to the surface of the tank. The top of the U-shaped fixing frame (3) presses the adjacent insulating bubbles (1) on both sides of the expansion gap (2) downward. The expansion joint (2) is provided with an elastic filler (4), which can adapt to the expansion and contraction of the insulating bubble (1).

2. An insulating slab for a cryogenic storage tank on an LPG carrier according to claim 1, characterized in that, The structure of the U-shaped fixing frame (3) is as follows: it includes an arc-welded bolt sleeve (301), a first screw (302), and a U-shaped metal fastener (30); the arc-welded bolt sleeve (301) is a blind hole structure with an open top, and an internal thread is provided inside the blind hole. The bottom of the arc-welded bolt sleeve (301) is welded to the surface of the tank in the expansion joint (2). The bottom of the U-shaped plate of the U-shaped metal fastener (30) is pressed against the top of the arc-welded bolt sleeve (301). The U-shaped plate of 30) extends horizontally on both sides and is pressed against the adjacent insulating bubble (1) on both sides of the expansion joint (2). The first screw (302) is provided with an external thread corresponding to the internal thread of the blind hole of the arc welding bolt sleeve (301). After the first screw (302) passes through the bottom of the U-shaped plate of the U-shaped metal fastener (30), it is matched and connected with the internal thread of the blind hole of the arc welding bolt sleeve (301). The bolt head at the top of the first screw (302) is pressed against the U-shaped plate of the U-shaped metal fastener (30).

3. An insulating slab for a cryogenic storage tank on an LPG carrier according to claim 1, characterized in that, The structure of the U-shaped fixing frame (3) includes an arc-welded screw (311), a screw connecting sleeve (312), and a U-shaped metal fastener (30). The arc-welded screw (311) is provided with an external thread, and the screw connecting sleeve (312) has an axial through-hole structure. The through-hole of the screw connecting sleeve (312) is provided with an internal thread. The screw connecting sleeve (312) is movably threaded onto the arc-welded screw (311). The bottom of the arc-welded screw (311) is welded and fixed to the surface of the tank in the expansion joint (2). The bottom of the U-shaped plate through the U-shaped metal fastener (30) is provided, the screw connecting sleeve (312) is located on the lower side of the U-shaped metal fastener (30), the U-shaped plate of the U-shaped metal fastener (30) extends horizontally on both sides and is matched and pressed on the adjacent insulating bubble blocks (1) on both sides of the expansion joint (2), the bolt head at the top of the arc welding screw (311) is matched and pressed on the U-shaped plate of the U-shaped metal fastener (30), and the screw connecting sleeve (312) is movable and adjusted on the arc welding screw (311) and pressed upward on the lower side of the U-shaped plate of the U-shaped metal fastener (30).

4. An insulating slab for a cryogenic storage tank on an LPG carrier according to claim 2 or 3, characterized in that, The U-shaped metal fastener (30) has a columnar groove (31) in the middle of the U-shaped plate corresponding to the bolt head, which matches the bolt head profile.

5. An insulating slab for a cryogenic storage tank on an LPG carrier according to claim 4, characterized in that, The upper side of the U-shaped metal fastener (30) is provided with a joint plug (5), and the joint plug (5) is provided with a plurality of extrusion reset grooves (51) in parallel in the vertical direction. The joint plug (5) is bonded and fixed to the U-shaped metal fastener (30) and the insulating bubble block (1) by applying adhesive.

6. A method for producing insulating slabs for cryogenic storage tanks of liquefied gas carriers as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. PUF or EPS block foam production: PUF or EPS block foam is produced by foaming large blocks of foam using specialized foaming equipment, with real-time monitoring of production process, temperature, and pressure parameters. S2. Bubble cutting: Automatically cut large pieces of foam into standard-sized insulating bubbles (1); S3. Curing / curing: The insulating foam blocks (1) are stacked and cured to stabilize their physical properties; S4. Flat plate precision cutting: Cut the cured insulating bubble block (1) into a flat plate of a set thickness; S5.NDT Non-destructive Testing: Ultrasonic testing is used to detect internal defects in insulating blocks (1); S6. Outline cutting: Cut the qualified flat plate into insulating bubble blocks that fit the curved surface of the tank (1). S7-S10. Multilayer composite: The lower insulating bubble block (1) is coated with glue, stainless steel wire mesh is laid, glue is coated again, and the upper insulating bubble block (1) is stacked to form a sandwich structure. S11-S12. Surface protection: After applying adhesive to the upper insulating bubble block (1), lay a stainless steel plate, aluminum plate, galvanized steel plate, GRP (fiberglass plate), or TPO outer sheath. S13. Pressing and shaping: Pressing tightly bonds the layers together to create a finished insulation board with markings and QR codes; S14. MES System Integration: Record the product model, size, inspection results, production and logistics information for each insulation board; S15. Packaging and Shipping: The robotic arm stacks and secures the pallets, completing the shipment process.

7. A construction and installation method for insulating slabs used in cryogenic storage tanks of liquefied gas carriers as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S101. Tank marking: Mark the laying position of insulating bubble blocks (1) on the surface of the liquid cargo tank; S102. Welding anchors: Weld bolts or sleeves for installing U-shaped fixing brackets (3) to the surface of the tank at the corresponding position of the expansion joint (2); S103. Install insulating bubbles (1): Lay the prefabricated insulating bubbles (1) in place and press them into the tank using the U-shaped fixing frame (3); S104. Filling with elastic filler (4): Injecting or embedding elastic filler (4) into the expansion joint (2); S105. Install joint plug (5): Install a joint plug (5) with a compression reset groove (51) above the U-shaped fixing frame (3), and fix it to the insulating bubble (1) and the U-shaped metal fastener (30) by adhesive. S106. Joint sealing treatment: Aluminum foil mesh, EVA / PE sealing module and TPO waterproof membrane are laid in sequence in the joint area and hot air welded to form a continuous sealing layer.

8. The application of the insulating slab as described in any one of claims 1 to 5 for cryogenic storage tanks on liquefied gas carriers in marine cryogenic storage and transportation equipment, characterized in that, The insulating plate structure is used in at least one of the following scenarios: The main cargo hold of an LNG carrier; LNG-powered fuel tank; LNG bunkering ship cargo tanks; Ethylene and ethane (LEG) carrier cargo tanks; Liquefied petroleum gas (LPG) cargo tank; Liquid ammonia (LAC) cargo tank; The insulating bubble block (1) is mechanically fixed to the tank body by a U-shaped fixing frame (3), and the expansion gap (2) is filled with elastic filler (4) and a joint plug (5) is provided to adapt to thermal expansion and contraction from -163℃ to room temperature, so as to ensure long-term sealing and structural integrity.

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