Installation of LNG fuel cabin vertical support pressure-bearing wood and vertical support epoxy pouring process

Abstract

The LNG fuel cabin vertical support pressure-bearing wood mounting and vertical support epoxy pouring process comprises the vertical support pressure-bearing wood mounting process and the vertical support epoxy pouring process, and has the advantages that low-temperature epoxy materials are high in construction reliability and good in quality; the stainless steel base plate can be used for adjusting the inclination (further adjusting the levelness of the fuel cabin) and compensating errors, and the fuel cabin can be restrained from sliding leftwards and rightwards.

Description

[0001] This application is a divisional application of the application filed on June 3, 2025, with application number CN202510732284.1, entitled "Installation of Pressure-Bearing Wooden Structure for LNG Fuel Tank and Method for Casting Low-Temperature Epoxy Material Thereof". Technical Field

[0002] This invention relates to the field of ship fuel tank modification technology, and in particular to the installation of pressure-bearing timber for vertical supports of LNG fuel tanks and the epoxy casting process for vertical supports. Background Technology

[0003] Given the increasing demands on ships for clean energy utilization, traditional ships need to convert from a single energy source to simultaneously utilize LNG fuel. This necessitates comprehensive modifications to the fuel tanks within existing ships. The structural design of fuel tanks in the current shipbuilding industry must consider multiple factors to ensure safety and reliability.

[0004] As is well known, ships sailing at sea are susceptible to wind and waves, which places high demands on the safety and reliability of modified fuel tanks. Furthermore, due to the low-temperature characteristics of the fuel inside the fuel tank, it is necessary to isolate the low temperature from the ship's hull structure. Summary of the Invention

[0005] The purpose of this invention is to provide an installation process for the pressure-bearing timber of the vertical support of the LNG fuel tank and an epoxy casting process for the vertical support. The construction process has high reliability, good construction quality and stability of the low-temperature epoxy material, and the stainless steel pad used in the process can adjust the level of the fuel tank, compensate for errors, and also restrain the lateral sliding of the fuel tank.

[0006] To solve the above-mentioned technical problems, the embodiments of the present invention provide an LNG fuel tank pressure-bearing timber installation and a method for casting low-temperature epoxy material, which includes a shore foundation construction step and a ship hull interior construction step. The shore foundation construction step includes the installation of vertical support pressure-bearing timber and its low-temperature epoxy material coating process.

[0007] The construction steps inside the hull include the epoxy casting process for vertical supports, the installation of anti-roll support pressure timber and its low-temperature epoxy casting process, the installation of longitudinal limiting support pressure timber and its low-temperature epoxy casting process, and the installation of anti-buoyancy support pressure timber and its low-temperature epoxy casting process.

[0008] A reasonable construction sequence is beneficial to improving the efficiency of load-bearing timber installation and low-temperature epoxy material application. The introduction of a temperature control step in the foundation construction process greatly improves the construction quality of this invention in harsh environments. Furthermore, the temperature control step utilizes the internal space of the shed to reduce the negative impact of the external environment on the load-bearing timber installation and low-temperature epoxy material application. These negative impacts are mainly reflected in the following aspects:

[0009] Firstly, the construction of low-temperature epoxy materials needs to be carried out under preset temperature and humidity conditions, and the emergence of the shed allows for the dynamic adjustment of temperature and humidity within the space using the control equipment inside the shed.

[0010] Secondly, the canopy can block direct sunlight from hitting the pressure wood and low-temperature epoxy materials, thus preventing the degradation of the properties of materials such as low-temperature epoxy materials due to direct sunlight.

[0011] The leveling process during internal hull construction can be achieved by using stainless steel shims to adjust the tilt (and thus the leveling of the fuel tank) to compensate for errors, and also by restraining the left and right slippage of the fuel tank. This is because the surface of the stainless steel shims provides the corresponding friction to achieve this purpose.

[0012] The LNG fuel tank pressure-bearing timber installation and its low-temperature epoxy material casting method provided by this invention, wherein the installation of the vertical support pressure-bearing timber is carried out after the fuel tank insulation laying is completed and before the fuel tank is hoisted, includes the following steps:

[0013] Before installing the pressure timber, remove rust, welding slag, and oil stains from the inner surface of the bottom support baffle. After cleaning, apply anti-rust paint.

[0014] Inspect the flatness and levelness of each vertical support at the bottom of the fuel tank, as well as the installation accuracy of the support baffles;

[0015] After the pressure timber is lifted into place using a lifting trolley, it is coated with low-temperature epoxy material for installation. The pressure timber is then secured to the fuel tank support using bolts coated with grease, through pre-drilled M20mm tapped threaded holes on the pressure timber and φ22mm holes on the left and right flat steel of the fuel tank support.

[0016] After all the pressure timbers for the fuel tanks are installed in place, the flatness and levelness of the lower surface of the pressure timbers are measured according to the preset requirements, and the data are recorded as a reference for the lifting and positioning of the fuel tanks.

[0017] After all the pressure timber installation measurements were completed, the outer surface was covered with plastic film, ready for the fuel tank to be hoisted.

[0018] The LNG fuel tank pressure timber installation and its low-temperature epoxy material casting method provided by this invention include the following:

[0019] Before the fuel tank is hoisted and positioned, the rust, rust spots, welding slag, and oil stains on the inner surface of the inner bottom support should be cleaned and coated with a layer of anti-rust paint with a film thickness not exceeding 30um.

[0020] Draw the stainless steel plate installation positioning line on the inside side of the inner bottom support plate;

[0021] Tighten the bolts through the pre-drilled tapped thread holes in the inner bottom support plate to the approximate installation height required for the stainless steel pad, 15mm from the inner surface of the support base plate.

[0022] Place the stainless steel pad on the pre-tightened support base plate bolts, and position the stainless steel pad by adjusting the height of the bolts so that it is flush with the upper surface and the surrounding plate.

[0023] After the fuel tank is hoisted and positioned, remove the bolts on both sides of the fuel tank support baffle used to fix the pressure wood, so that the pressure wood and the stainless steel pad are firmly attached. If the stainless steel pad is not firmly attached, adjust the bolts on the support base plate to make it firmly attached to the pressure wood.

[0024] Apply grease to the stainless steel backing plate; cleaning is carried out after the epoxy has cured.

[0025] Seal the area around the four corner vents of the stainless steel pad with sealant to prevent epoxy resin from overflowing. Also seal the gap between the stainless steel pad and the support baffle with epoxy resin.

[0026] Epoxy resin is poured through the pre-drilled pouring hole on the support base plate. The pouring of epoxy resin is observed through the four corner vent holes of the stainless steel pad until the epoxy resin overflows from the vent holes of the stainless steel pad, and then the pouring port ball valve is closed.

[0027] After the epoxy resin is poured, a tube is inserted into one of the vent holes to replenish the epoxy resin, so that the epoxy liquid inside the support is completely filled.

[0028] During the epoxy resin curing period, the epoxy resin seal must not be damaged, and the pouring port ball valve must not be opened.

[0029] After the epoxy has fully cured, remove the sealant from the stainless steel pad and remove the lifting bolts under the support base plate. Fill the openings of the lifting bolts with epoxy putty, and retain the ball valve at the pouring port.

[0030] In the LNG fuel tank pressure-bearing timber installation and low-temperature epoxy material casting method provided by this invention, the anti-sway support pressure-bearing timber is installed after the fuel tank is hoisted and positioned. The stainless steel angle steel baffle on one side of the fuel tank support is loosely installed after the pressure-bearing timber is positioned, and after being fixed with bolts and sealed with silicone, the low-temperature epoxy resin is cast. The installation process of the anti-sway support pressure-bearing timber and the low-temperature epoxy material casting process include:

[0031] Before the fuel tank is hoisted, clean the rust, welding slag, and oil stains on the inner surface of the support according to the requirements of the low-temperature epoxy resin supplier. After cleaning, apply anti-rust paint with a film thickness not exceeding 30um.

[0032] The pressure-bearing timbers are pre-placed near the corresponding inner bottom supports before the fuel tank is hoisted;

[0033] After the fuel tank hoisting and positioning fixtures are completed, the corresponding pressure timber is placed into the support, and the pressure timber is pushed to the approximate position by using bolts coated with grease through the tapped thread holes pre-drilled on the web of the fuel tank support.

[0034] Insert a stainless steel plate with a 2mm gap to ensure the gap between the inner bottom support web and the bearing timber;

[0035] Tighten the bolts again to push the pressure wood, so that the pressure wood is firmly attached to the inserted stainless steel plate, ensuring the theoretical thickness of the low-temperature epoxy resin is 30mm.

[0036] After the pressure-bearing timber is installed in place, the gap between it and the support baffle is sealed. After the sealing is completed, low-temperature epoxy resin is poured.

[0037] The installation of the LNG fuel tank pressure-bearing timber and its low-temperature epoxy material casting method provided by this invention includes the following steps:

[0038] Before the fuel tank is hoisted, the inner surface of the support is cleaned according to the requirements of the epoxy supplier. After the cleaning is completed, a layer of anti-rust paint is applied, and the paint film thickness does not exceed 30 μm.

[0039] The pressure-bearing timbers are pre-placed near the corresponding inner bottom supports before the fuel tank is hoisted;

[0040] After the fuel tank hoisting and positioning work is completed, the corresponding pressure timber is placed into the support, and the pressure timber is pushed to the approximate position through the pre-drilled tapped thread holes on the web of the fuel tank support using M20X75 bolts coated with grease.

[0041] To ensure that the stainless steel plate can be easily removed after epoxy curing, a 2mm gap is inserted, and grease is applied to the stainless steel surface and crescent holes are made to ensure the gap between the inner bottom support web plate and the bearing wood.

[0042] Tighten the bolts again to push the pressure wood, so that the pressure wood and the inserted stainless steel plate are firmly attached to each other, ensuring the theoretical thickness of the epoxy pouring is 30mm.

[0043] After the pressure-bearing timber is installed in place, the gap between it and the support baffle is sealed. After the sealing work is completed, epoxy is poured.

[0044] The LNG fuel tank pressure-bearing timber installation and its cryogenic epoxy material casting method provided by this invention include the following casting processes: the cryogenic epoxy material casting process for the anti-sway support pressure-bearing timber and the cryogenic epoxy material casting process for the longitudinal limiting support pressure-bearing timber.

[0045] Check that all load-bearing timbers are in place;

[0046] Use yellow sponge-specific strips and transparent silicone to seal the gap between the pressure-bearing wood and the baffle.

[0047] When the space is relatively small, rigid polyethylene strips can be used to push in from the side of the support for sealing in the aforementioned steps;

[0048] Epoxy resin is poured through the pre-drilled pouring hole on the web of the bearing until it overflows from the gap between the top baffle of the bearing and the sealant.

[0049] Clean up any excess epoxy resin that has overflowed from the gap above the support;

[0050] During the epoxy resin curing period, the epoxy seal must not be damaged, and the pouring port ball valve must not be opened;

[0051] After the epoxy has fully cured, remove the 2mm thick stainless steel plate used for positioning and remove the sealing material between the support baffle and the pressure wood.

[0052] The ball valve at the pouring port and the push bolts of the pressure wood should be retained and not removed. The push bolts need to be tightened after the epoxy has cured (this is to ensure good stress distribution between the pressure wood and the epoxy resin).

[0053] The LNG fuel tank pressure-bearing timber installation and its low-temperature epoxy material casting method provided by this invention involves installing the anti-buoyancy support pressure-bearing timber after the overall section hoisting, positioning, and welding are completed. The installation process of the anti-buoyancy support pressure-bearing timber and the low-temperature epoxy material casting process include:

[0054] Before hoisting the fuel tank, remove rust, welding slag, and oil stains from the inner surface of the anti-buoyancy device baffle. After cleaning, apply anti-rust paint with a film thickness not exceeding 30µm.

[0055] After the main section hoisting and positioning welding work was completed, the installation position of the pressure timber was adjusted. Bolts coated with grease were used to lift the pressure timber to the theoretical thickness of 15mm of low-temperature epoxy resin through the tapped thread holes pre-drilled on the bottom plate of the anti-buoyancy support of the fuel tank.

[0056] After all the load-bearing timbers are installed in place, the levelness of the upper surface of the load-bearing timbers is measured to ensure that the levelness between them is ≤4mm.

[0057] The casting process of the low-temperature epoxy material for the anti-buoyancy support includes:

[0058] Check that all the load-bearing timbers are installed in place. If any load-bearing timbers are not in place, adjust them using the lifting bolts on the support base plate. Measure the levelness of the upper surface of the load-bearing timbers to ensure that the levelness between them is ≤4mm.

[0059] Use yellow sponge strips and transparent silicone to seal the gap between the pressure wood and the baffle. On the end of the anti-buoyancy support without the baffle, open a pouring port and a vent on the sealing sponge.

[0060] Epoxy resin is injected through the pouring port on the sealing sponge at the unbaffled end of the anti-buoyancy support until the epoxy resin overflows from the vent holes left on the sealing sponge.

[0061] Clean up any spilled epoxy resin;

[0062] The epoxy seal must not be damaged during the epoxy resin curing period.

[0063] After the epoxy resin has fully cured, remove the sealing material between the anti-buoyancy support baffle and the pressure wood.

[0064] The positioning bolts for lifting the pressure timber should be retained and not removed.

[0065] After all epoxy resin has been poured and fully cured, remove the sponge strips from all supports, clean them thoroughly, and fill them with epoxy putty.

[0066] In the LNG fuel tank pressure-bearing wood installation and its low-temperature epoxy material casting method provided by the present invention, the cup-shaped seat of the lifting tool trolley is arranged in two rows and two columns on the surface of the lifting tool trolley. The lifting tool trolley has two vertical adjustment rails and two horizontal adjustment rails located between the vertical adjustment rails. The bottom of the cup-shaped seat is provided with sliding support feet that match the vertical adjustment rails and the horizontal adjustment rails. The bowl of the cup-shaped seat has locking bolts distributed at its bottom. The locking bolts pass through the bottom of the bowl-shaped seat and are provided with rubber sleeves. The inner side wall of the bowl of the cup-shaped seat is provided with an annular horizontal line. When liquid is placed in the bowl of the cup-shaped seat, it is observed whether the upper surface of the liquid coincides with the annular horizontal line to determine whether the lifting tool trolley is in a horizontal state. The horizontal adjustment rail is provided with a number of high-pressure air holes arranged in a regular manner. The high-pressure air holes are connected to the purging air source.

[0067] In the process of vertical support bearing wood epoxy casting, a dynamic release device is installed at the four corner vent holes of the stainless steel pad.

[0068] In the LNG fuel tank pressure timber installation and its low-temperature epoxy material casting method provided by the present invention, the low-temperature epoxy resin used is JM-98L. First, the B component of JM-98L epoxy putty is poured into the A component. The material is mixed at a low speed and uniformly using a deaerator to achieve uniform color between the two components A and B without color difference.

[0069] Then, after stirring, let it stand for a few minutes to allow the air bubbles in the adhesive to dissipate.

[0070] Finally, pour the mixed adhesive into the pump inlet funnel, start the grouting pump to pump the mixed adhesive into the grouting area until adhesive overflows from the vent.

[0071] The LNG fuel tank pressure-bearing timber installation and its low-temperature epoxy material casting method provided by this invention include a shore foundation construction step with a temperature control system, which includes:

[0072] The insulated shed is installed in the epoxy material construction area;

[0073] A temperature control system is installed in the epoxy material construction area and includes at least one temperature sensor, at least one heating fan and a control module. The temperature sensor and the heating fan are both connected to the control module.

[0074] When the temperature sensor detects a temperature below 13℃, the control module controls the heating fan to work; when the temperature sensor detects a temperature above 35℃, the control module controls the heating fan to stop working.

[0075] In the LNG fuel tank pressure-bearing wood installation and its low-temperature epoxy material casting method provided by the present invention, the heating fan is installed at the sweeping mechanism, the sweeping mechanism has a base with a U-shaped cross section, an installation platform is set inside the base, a bearing is installed at the installation platform, a vertical shaft is installed at the bearing, a shaft gear is set on the vertical shaft, the shaft gear is driven by a motor, a disc is set at the top of the vertical shaft, and multiple hemispherical recesses are arranged at equal intervals around the top of the base, with beads arranged inside the recesses, and the lower side of the disc cooperates with the beads;

[0076] The disk and the vertical shaft are connected by a number of connectors, which have the following characteristics:

[0077] The first rod is located on the lower side of the disk, and several inclined limiting bodies are arranged circumferentially at the bottom of the first rod.

[0078] A first plate is arranged at the top of the vertical axis, and a first plate through hole is provided on the first plate;

[0079] After the first rod and the inclined limiting body pass through the through hole of the first plate, the inclined limiting body unfolds to limit the movement.

[0080] The vertical axis has a planar structure on one side, and the disk has a structural notch in the middle.

[0081] In the LNG fuel tank pressure-bearing wood installation and its low-temperature epoxy material casting method provided by the present invention, an outer convex ring and an inner convex ring are respectively provided on the outer and inner sides of the top of the base. The top heights of the outer convex ring and the inner convex ring are the same, and the top height of the outer convex ring is less than the top height of the ball. A top convex ring is provided on the outer periphery of the bottom of the disc. The top convex ring and the outer convex ring cooperate. A left vent is provided on the left side of the top convex ring, with the inlet of the left vent facing the left rear. A right vent is provided on the right side of the top convex ring, with the inlet of the right vent facing the right rear.

[0082] The method provided by this invention has the advantages of reliable construction process and good quality of low-temperature epoxy material casting. Attached Figure Description

[0083] Figure 1 This is a schematic diagram of the B-type fuel tank in the first embodiment of the present invention, which is located inside the cargo hold of the ship.

[0084] Figure 2 This is a diagram showing the arrangement of the bottom support for the LNG fuel tank in the first embodiment of the present invention.

[0085] Figure 3 This is a diagram showing the arrangement of the top support for the LNG fuel tank in the first embodiment of the present invention.

[0086] Figure 4 This is a diagram illustrating the effect of the pressure-bearing timber installation and lifting trolley pushing the pressure-bearing timber to the fuel tank support in the first embodiment of the present invention.

[0087] Figure 5 This is a schematic diagram of the anti-sway support structure in the first embodiment of the present invention.

[0088] Figure 6 The first embodiment of the present invention Figure 5 Enlarged view of HY1 in the middle.

[0089] Figure 7 The first embodiment of the present invention Figure 5 Enlarged view of HY2 in the middle.

[0090] Figure 8 The first embodiment of the present invention Figure 5 Enlarged view of HY3 in the middle.

[0091] Figure 9 This is a schematic diagram of the partial sealing construction at the anti-sway support in the first embodiment of the present invention.

[0092] Figure 10 This is a schematic diagram of the vertical support structure in the first embodiment of the present invention.

[0093] Figure 11 This is a magnified view of a section where the bearing wood and stainless steel plate meet in the vertical support.

[0094] Figure 12 This is a magnified view of a portion of the vertical support where the bearing timber meets the hull support.

[0095] Figure 13 This is a schematic diagram of the epoxy casting of the vertical support in the first embodiment of the present invention.

[0096] Figure 14 This is a schematic diagram of the epoxy casting of the anti-roll and longitudinal limiting support in the first embodiment of the present invention.

[0097] Figure 15 for Figure 14 Schematic diagram of the P-direction structure.

[0098] Figure 16 This is a schematic diagram of the longitudinal limiting support in the first embodiment of the present invention.

[0099] Figure 17 This is a schematic diagram of the anti-buoyancy support in the first embodiment of the present invention.

[0100] Figure 18 for Figure 17 Enlarged view of a portion of the ZF region.

[0101] Figure 19 This is a flowchart illustrating the installation of pressure-bearing timber in the LNG fuel tank and the method for casting cryogenic epoxy material in the first embodiment of the present invention.

[0102] Figure 20 This is a partial structural diagram of the fuel tank support portion of the vertical support and the pressure timber in the shore foundation construction state according to the second embodiment of the present invention.

[0103] Figure 21 This is a cross-sectional view of the fit between the fuel tank support portion of the vertical support and the bolt holes of the pressure timber in the second embodiment of the present invention.

[0104] Figure 22 This is a schematic diagram of the dynamic release device at the four corner vent holes of the stainless steel pad in the step of vertical support pressure-bearing wood epoxy casting in the third embodiment of the present invention.

[0105] Figure 23 This is an enlarged view of the dynamic release device in the third embodiment of the present invention.

[0106] Figure 24 This is a schematic diagram of a lifting tooling trolley in the fourth embodiment of the present invention.

[0107] Figure 25 This is a three-dimensional schematic diagram of a temperature control device for epoxy material construction, taken from the first direction.

[0108] Figure 26 This is a three-dimensional schematic diagram of a temperature control device for epoxy material construction from the second direction.

[0109] Figure 27 This is a sectional view of the air sweeping mechanism.

[0110] Figure 28 for Figure 27 Enlarged view at point P1.

[0111] Figure 29 for Figure 27 Enlarged view at P2 in the middle.

[0112] Figure 30 This is a top view along the vertical axis.

[0113] Figure 31 This is a top-down example of a sweeping mechanism.

[0114] Figure 32 for Figure 31 Enlarged view at P3.

[0115] Figure 33 for Figure 31 Enlarged view at page 4.

[0116] Explanation of reference numerals in the attached figures:

[0117] 1. Lifting trolley; 2. Pressure-bearing timber; 3. Bowl-shaped seat; 4. Pad plate; 5. Fuel tank support portion of vertical support; 6. Low-temperature epoxy resin; GAP, stainless steel plate insertion gap; 7. Baffle (also known as cofferdam); 8. Inner bottom support web plate; 9. Stainless steel plate; 10. Pressure relief hole; 11. Sealing body; 12. Inner bottom support portion of vertical support; 13. Stainless steel pad plate; 14. Loose sleeve; 15. Ball valve; 16. Hoses; 17. Inner bottom plate portion of anti-roll support; 18. Fuel tank support portion of anti-roll support; 19. Overflow chamber; 20. Bolts; 21. Dynamic release device.

[0118] 200 Fuel tank, 201 Insulated shed, 201a Column, 201b Top cover, 201c Side wall, 202 Temperature sensor, 203 Heating fan, 204 Control module, 205 Desktop, 206 Sweeping mechanism, 206a Base, 206b Mounting platform, 206c Bearing, 206d Vertical shaft, 206e Shaft gear, 206f Disc, 206g Ball, 206h Outer convex ring, 206i Inner convex ring, 206j First rod, 206k Inclined limiting body, 206l First plate, 206m Top convex ring, 206n Left side vent, 206o Right side vent, 206p Planar structure, 206q Structural notch. Detailed Implementation

[0119] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0120] The first embodiment of the present invention provides an LNG fuel tank pressure-bearing timber installation method and a low-temperature epoxy material casting method. The method includes shore foundation construction steps and ship cabin interior construction steps. The shore foundation construction step is carried out on the ground, for example, near a dock. The ground needs to be flat, and the LNG fuel tank can be hoisted using equipment such as gantry cranes (the LNG fuel tank can be placed on the ground using support devices, such as brackets). The ship cabin interior construction step is carried out inside the LNG fuel tank (i.e., inside the ship). After scientifically allocating the construction steps, the use of the site will be more reasonable, avoiding the constraints on construction efficiency caused by factors such as narrow site space. The fuel tank bears the load and isolates the low temperature conduction to the ship structure through corresponding supports and pressure-bearing timber.

[0121] See Figure 19 The figure shows the process flow diagram of the present invention. As can be seen from the figure, the process flow includes the construction steps of the fuel tank support portion and pressure timber of the vertical support → the construction steps of the anti-roll support, longitudinal restraint support and pressure timber → the construction steps of the hull bottom support portion and pressure timber of the vertical support → the construction steps of the anti-buoyancy support and pressure timber. The construction process of the fuel tank support portion and pressure timber of the vertical support is completed on the shore foundation, while the subsequent processes are completed inside the ship's hull. Furthermore, the subsequent process steps can be carried out concurrently or interchangeably, for example, the construction steps of the anti-roll support, longitudinal restraint support and pressure timber, and the construction steps of the hull bottom support portion and pressure timber of the vertical support. It should be noted that this construction process can also effectively address the LNG fuel tank retrofit requirements of existing cargo ships.

[0122] This invention is based on Figure 1The Type B fuel tank M shown is illustrated as an example. The Type B fuel tank is not part of the hull structure; it is supported by vertical supports in the cargo hold area, and the relative displacement between the fuel tank and the hull structure is limited by anti-roll supports and longitudinal restraint supports. Furthermore, to prevent damage to the hull structure from the fuel tank floating in the cargo hold area due to hull damage, anti-buoyancy supports are installed at the lower part of the top ramp of the fuel tank. The pressure-bearing timber for all types of LNG fuel tank supports is made of German beech laminated wood. This beech support block can withstand an ambient temperature of 45 degrees Celsius (cargo hold) and a minimum cargo temperature of -163 degrees Celsius (fuel tank). As an alternative, this case uses Lignostone® (LCW) pressure-bearing timber from Lignostone Industrial Products Sales (Shanghai) Co., Ltd. The low-temperature epoxy material used is EPOCAST 36-P low-temperature epoxy casting material from Yigong Polymer (Wujiang) Co., Ltd. This material has two components, A and B, which are mixed before use. For example, 20 kg of component A and 2.4 kg of component B result in a total of 22.4 kg of mixed low-temperature epoxy material. During construction in low-temperature environments, such as winter when the ambient temperature is below 13°C, component A of the epoxy putty needs to be heated (40°C for 24 hours). This low-temperature epoxy material exhibits excellent pressure-bearing and adhesion properties under low-temperature conditions, ensuring uniform stress distribution on the LNG fuel tank support.

[0123] from Figure 2 It can be seen that the bottom supports of the LNG fuel tank are arranged regularly in both the horizontal and vertical directions, which will... Figure 2 The left and right directions are defined as the transverse direction, and the up and down directions are defined as the longitudinal direction. The first row (transverse direction) has first LNG fuel tank bottom supports (VSA-1) at both ends. Between the two first LNG fuel tank bottom supports (VSA-1) are four second LNG fuel tank bottom supports (VSA-2). The second row has six third LNG fuel tank bottom supports (VSB). The arrangement of the LNG fuel tank bottom supports in the penultimate row is the same as in the first row, and the arrangement in the second-to-last row is the same as in the second row. Vertical supports provide vertical support to the fuel tank. Vertical supports consist of two parts: LNG fuel tank bottom supports and corresponding hull supports. During shore-based construction, the installation of pressure timber and epoxy coating (painting) between the pressure timber and the LNG fuel tank bottom supports must be completed to achieve relative fixation of the pressure timber between the LNG fuel tank bottom supports. The process is described in detail below. The installation of the vertical support pressure timber and the epoxy coating method are as follows:

[0124] The installation of the pressure-bearing timber for the vertical supports (bottom support section of the LNG fuel tank) is carried out after the insulation of the LNG fuel tank is laid and before the fuel tank is hoisted. It includes the following steps:

[0125] 1. Before installing the pressure-bearing timber, rust, welding slag, and oil stains on the inner surface of the LNG fuel tank support baffle must be removed, and a layer of anti-rust paint should be applied after cleaning.

[0126] 2. Inspect the flatness and levelness of each vertical support at the bottom of the LNG fuel tank, as well as the installation accuracy of the support baffles. The data must meet the requirements of the accuracy management documents.

[0127] 3. After using the lifting trolley 1 to lift the pressure-bearing timber 2 into position, refer to... Figure 4 The lifting trolley 1 (including but not limited to the scissor lift) has a cup-shaped seat 3 equipped with a pad 4. The pressure-bearing wood 2 is placed on the pad 4. The pad can effectively distribute the pressure of the pressure-bearing wood to the four cup-shaped seats. The upper surface of the pressure-bearing wood is coated with PHILLYMASTIC TG-7B low-temperature epoxy material for upward loading operations (until...). Figure 4 As shown in the diagram, the pressure wood is securely fixed to the fuel tank support portion 5 of the vertical support using bolts coated with grease, through pre-drilled M20mm tapped threaded holes on the pressure wood 2 and φ22mm holes on the left and right flat steel of the fuel tank support. After coating the upper surface of the pressure wood with low-temperature epoxy material, a step of re-pressing with a vibrating plate is performed. This step can effectively remove air bubbles, voids, and other problems inside the low-temperature epoxy material, improving the internal density of the low-temperature epoxy material.

[0128] 4. After all the pressure timbers for the LNG fuel tanks are installed in place, the flatness and levelness of the lower surface of the pressure timbers are measured according to the preset requirements, and the data are recorded as a reference for the lifting and positioning of the fuel tanks. Pressure timbers that do not meet the installation accuracy standards are adjusted until the accuracy requirements are met. It should be noted that after the LNG fuel tanks are placed in the ship's hold, the pressure timbers, due to their placement in... Figure 10 On the stainless steel pad shown, low-temperature epoxy resin will be poured below the stainless steel pad 13. At this time, the thickness of the low-temperature epoxy resin is selected according to the corresponding error to achieve the preset requirements of the installation accuracy of the pressure wood.

[0129] 5. After all the pressure timber installation measurements are completed, the outer surface is covered with plastic film in preparation for the fuel tank hoisting.

[0130] The above processes fall under the category of shore foundation construction operations, which can be carried out on the ground near the dock.

[0131] The above process is completed on the ground near the dock. Since LNG fuel tanks are typically large, shore-based construction avoids the constraints of shipboard space on the installation of pressure timber. Low-temperature epoxy materials have strict temperature requirements for shore-based operations, which include temperature control. A removable temperature-controlled shed is installed at the LNG fuel tank shore-based construction site. This shed contains temperature sensors and temperature control equipment. When the internal temperature of the shed falls below a preset value, the temperature control equipment is activated to adjust the temperature to the preset construction temperature. Notably, this temperature-controlled shed prevents the low-temperature epoxy materials from being exposed to direct sunlight.

[0132] After the shore-based construction of the LNG fuel tank was completed, it was hoisted into the ship's hold using lifting equipment. The distribution locations of the anti-roll supports are shown in [reference needed]. Figure 2 and Figure 3 ,exist Figure 2 In the middle, there are six LRS (Low Sway Supports) distributed in the first anti-roll bearing. Figure 3 The second anti-roll bearing URS has six distributions. See also Figure 5 The anti-roll support pressure timber is installed after the fuel tank is hoisted and positioned. The anti-roll support is designed to limit the relative movement between the LNG fuel tank and the hull when the ship rolls. This structure limits the lateral displacement of the liquid cargo fuel tank but cannot constrain the movement of the fuel tank in other directions. The anti-roll support pressure timber is installed after the fuel tank is hoisted and positioned. The stainless steel angle steel baffle on one side of the fuel tank support is loosely installed after the pressure timber is installed and positioned. After being fixed with bolts and sealed with silicone, the low-temperature epoxy resin is poured. The process includes the following steps:

[0133] 1. Before hoisting the fuel tank, clean the rust, welding slag, and oil stains on the inner surface of the support according to the requirements of the low-temperature epoxy resin supplier. After cleaning, apply anti-rust paint with a film thickness of no more than 30um, preferably 15um.

[0134] 2. To facilitate construction, the pressure-bearing timbers are placed in advance near the corresponding inner bottom supports (inside the ship's hold) before the fuel tank is hoisted.

[0135] 3. After the fuel tank hoisting and positioning work is completed, place the corresponding pressure-bearing timber into the support (i.e., Figure 5 Between the inner bottom plate portion 17 of the anti-roll bearing and the fuel tank bearing portion 18 of the anti-roll bearing, three baffles are arranged on the side of the inner bottom plate portion 17 where the pressure timber is installed, while no metal baffle is arranged on the side where the pressure timber is pushed in. After the pressure timber is pushed into place, the gap is sealed with a retaining strip to allow for the pouring of low-temperature epoxy material. Figure 9The diagram shows a partial effect of sealing the low-temperature epoxy casting gap with a sealing strip. Considering the overflow problem, two overflow chambers (19) are distributed at the outlet of the casting gap. M20X75 bolts coated with grease are used to push the bearing wood to its approximate position through the pre-drilled tapped thread holes on the web of the fuel tank support. Figure 5 The state shown.

[0136] 4. A stainless steel plate with a 2mm gap is inserted between the web plate 8 of the inner bottom support (i.e., the web plate of the inner bottom plate portion 17 of the anti-roll support) and the bearing timber 2. Figure 8 The stainless steel plate shown is inserted into the gap GAP (not shown in the figure). Figure 9 The diagram shows a stainless steel plate (9) to ensure the gap between the inner bottom support web and the bearing timber. It should be noted that to ensure easy removal of the stainless steel plate after epoxy curing, grease can be applied to the stainless steel surface and crescent-shaped holes can be made. The stainless steel plate can be 1.5m long and 20cm wide. This long strip of stainless steel serves as a temporary insert structure and needs to be removed from the gap between the inner bottom support web and the bearing timber after construction.

[0137] 5. See also Figure 6-8 As shown, tighten the bolts again to push the pressure wood, so that the pressure wood and the inserted stainless steel plate are firmly attached to each other, ensuring the theoretical thickness of the low-temperature epoxy resin is 30mm. Figure 6 The 20mm dimension marked in section 7 refers to the thickness of the low-temperature epoxy material between the baffle and the pressure-bearing wood, and the 30mm dimension refers to the thickness of the low-temperature epoxy material between the pressure-bearing wood and the corresponding support. Figure 7 The height of the middle baffle is 100mm.

[0138] 6. After the pressure-bearing timber is installed in place, seal the gap between it and the support plate using sealing strips. After sealing, begin pouring low-temperature epoxy resin. See also Figure 9The figure shows the state after the pressure-bearing wood and the support baffle 7 are sealed by the sealing body 11 (the sealing body is made by first filling the gap with flexible foam strips or flexible strips and then applying glue). A protective layer is laid on the surface of the pressure-bearing wood. After the sealing body is sealed, two pressure relief holes 10 are opened on the protective layer on the surface of the pressure-bearing wood at both ends of the baffle. These pressure relief holes facilitate the pouring of low-temperature epoxy material into the gap between the support and the pressure-bearing wood. On the other hand, they can also be used to observe whether the amount of low-temperature epoxy material poured is sufficient. More importantly, the pressure relief holes can be used to inject low-temperature epoxy material into the two pressure relief holes when the low-temperature epoxy material shrinks, so as to avoid the problem that the internal gap is too small when replenishing the low-temperature epoxy material, which will prevent the replenishment of low-temperature epoxy material. In addition, the pressure relief holes also have the function of heat dissipation, so that the heat released during the solidification process of the low-temperature epoxy material can be released in time. The outlet of the pressure relief hole has an overflow chamber 19 enclosed by flexible foam strips. Low-temperature epoxy material can flow from the inner cavity of the overflow chamber 19 into the gap between the pressure-bearing timber and the support through the pressure relief hole. The curing of the low-temperature epoxy resin begins in the central area of ​​the pressure-bearing timber, during which some shrinkage occurs. Excess resin in the overflow chamber is used for replenishment. For larger pressure-bearing timbers, epoxy resin must be added to the pressure relief hole. Therefore, close observation is necessary during the epoxy resin deposition and curing process. It is important to note that while heating equipment should be evenly distributed at the pouring site, the environment should be disturbed using fans to avoid hot spots. Hot spots can cause excessive exothermic reactions during the initial curing process, affecting the quality of the pouring and the stability of the structure in later use.

[0139] Longitudinal limiting support (see structure) Figure 16 The installation process for the bearing timber can refer to the installation process for the anti-sway bearing timber, and will not be repeated here. The longitudinal limiting support, however, is... Figure 2 As can be seen from the diagram, the first longitudinal restraint support PSA is distributed in the first row and the last row of the fuel tank, and the second longitudinal restraint support PSB is distributed in the second row and the second to last row of the fuel tank.

[0140] The following describes the steps for epoxy casting of vertical support bearing wood, including:

[0141] 1. Before the fuel tank is hoisted and positioned, the rust spots, welding slag, and oil stains on the inner surface of the inner bottom support should be cleaned and coated with a layer of anti-rust paint. The paint film thickness should not exceed 30um.

[0142] 2. See Figure 10 Mark the installation positioning line of stainless steel pad 13 on the inside side of the inner bottom support (i.e., the hull bottom support part 12 of the vertical support).

[0143] 3. Tighten the M20X75 bolt (coated with grease) through the pre-drilled tapped thread hole in the inner bottom support plate to the approximate installation height required for the stainless steel pad, 15mm from the inner surface of the support base plate.

[0144] 4. Place the stainless steel pad 13 onto the pre-tightened support base plate bolts. Adjust the height of the bolts to position the stainless steel pad 13 so that its upper surface is flush with the surrounding plate, i.e., the theoretical thickness of the epoxy pouring is 18mm (see...). Figure 10-12 ). Figure 11 The thickness of the stainless steel pad 13 is 10mm, the distance between the stainless steel pad 13 and the baffle is 5mm, the height of the baffle is 75mm, and the thickness of the low-temperature epoxy material is 18mm.

[0145] 5. After the fuel tank is hoisted and positioned (i.e., hoisted from the shore base to the ship's hold), remove the bolts on both sides of the fuel tank support baffle used to fix the pressure-bearing timber, so that the pressure-bearing timber and the stainless steel pad are firmly attached. If the stainless steel pad is not firmly attached, adjust the bolts on the support base plate to make it firmly attached to the pressure-bearing timber.

[0146] 6. Apply grease to the stainless steel backing plate. Cleaning should be done after the epoxy has cured.

[0147] 7. Seal the area around the four corner vents of the stainless steel pad 13 with sealant to prevent epoxy resin from overflowing. Also seal the gap between the stainless steel pad and the support baffle with epoxy resin.

[0148] 8. Pour epoxy resin through the pre-drilled pouring holes in the support base plate [see...] Figure 13 The figure shows a loose sleeve 14 installed at the pouring hole, a ball valve 15 connected to the loose sleeve, and a hose 16 connected to the ball valve 15. The hose is connected to a low-temperature epoxy material supply system to complete the pouring operation. The epoxy resin pouring is observed through the vent holes at the four corners of the stainless steel pad until the epoxy resin overflows from the vent holes of the stainless steel pad, at which point the pouring port ball valve is closed.

[0149] 9. After the epoxy resin is poured, insert a tube into one of the vent holes to replenish the epoxy resin, so that the epoxy liquid inside the support is completely filled.

[0150] 10. During the epoxy resin curing period, the epoxy resin seal must not be damaged, and the pouring port ball valve must not be opened.

[0151] 11. After the epoxy has fully cured, remove the sealant from the stainless steel pad and remove the lifting bolts under the support base plate. Fill the openings of the lifting bolts with epoxy putty, and retain the ball valve at the pouring port.

[0152] The epoxy casting process for the anti-roll and longitudinal restraint supports is described below, including:

[0153] 1. Check that all load-bearing timbers are installed in place.

[0154] 2. Use yellow sponge strips and transparent silicone to seal the gap between the pressure wood and the baffle.

[0155] 3. When the space is relatively small, in step 2, a rigid polyethylene strip can be pushed in from the side of the support to seal it.

[0156] 4. Pour epoxy resin through the pre-drilled casting holes in the web of the support. [See...] Figure 14-15 , Figure 15 The diagram shows a loose sleeve 14 installed in the pouring hole, a ball valve 15 connected to the loose sleeve, and a hose 16 connected to the ball valve, until epoxy resin overflows from the gap between the top baffle of the support and the sealing material.

[0157] 5. Clean up any epoxy resin that has overflowed from the gap above the support.

[0158] 6. During the epoxy resin curing period, the epoxy seal must not be damaged, and the pouring port ball valve must not be opened.

[0159] 7. After the epoxy has fully cured, remove the 2mm thick stainless steel plate used for positioning and remove the sealing material between the support baffle and the pressure wood.

[0160] 8. The ball valve at the pouring port and the push bolts of the pressure wood should be retained and not removed. The push bolts need to be tightened after the epoxy has cured (this is to ensure good stress between the pressure wood and the epoxy resin).

[0161] The following describes the installation of the anti-buoyancy support bearing timber and its epoxy casting:

[0162] Install anti-buoyancy supports (see structure) Figure 17-18 FS anti-buoyancy support Figure 3 The pressure timber (with 7 in the first row and 7 in the last row) on top of the fuel tank is installed after the main section is hoisted, positioned, and welded. This process includes the following steps:

[0163] 1. Before hoisting the fuel tank, remove rust, welding slag, and oil stains from the inner surface of the anti-buoyancy device baffle. After cleaning, apply anti-rust paint with a film thickness not exceeding 30µm.

[0164] 2. After the hoisting and positioning welding of the main section is completed, the installation position of the pressure timber is adjusted. Bolts coated with grease are used to lift the pressure timber to a theoretical thickness of 15mm for the low-temperature epoxy resin by passing through the tapped thread holes pre-drilled on the bottom plate of the anti-buoyancy support of the fuel tank.

[0165] 3. After all the load-bearing timbers are installed, measure the levelness of the upper surface of the load-bearing timbers to ensure that the levelness between them is ≤4mm.

[0166] The epoxy casting process for the anti-buoyancy support includes:

[0167] 1. Check whether all the load-bearing timbers are installed in place. If any load-bearing timbers are not in place, adjust them using the lifting bolts on the support base plate. Measure the levelness of the upper surface of the load-bearing timbers to ensure that the levelness between them is ≤4mm.

[0168] 2. Use yellow sponge strips and transparent silicone to seal the gap between the pressure-bearing wood and the baffle. Open a pouring port and a vent on the sealing sponge at the end of the anti-buoyancy support without the baffle.

[0169] 3. Inject epoxy resin through the pouring port on the sealing sponge at the unbaffled end of the anti-buoyancy support until the epoxy resin overflows from the vent holes left on the sealing sponge.

[0170] 4. Clean up any spilled epoxy resin.

[0171] 5. The epoxy seal must not be damaged during the epoxy resin curing period.

[0172] 6. After the epoxy resin has fully cured, remove the sealing material between the anti-buoyancy support baffle and the pressure wood.

[0173] 7. The positioning bolts for lifting the pressure timber should be retained and not removed.

[0174] After all epoxy resin has been poured and fully cured, remove the sponge strips from all supports, clean them thoroughly, and fill them with epoxy putty.

[0175] The installation process of the floating support pressure wood and its epoxy casting, as well as the installation process of the longitudinal limiting support pressure wood, can also refer to the existing technology. During the casting process (which has the same meaning as casting), if there is a gap between the pressure wood and the corresponding support (baffle), the sealing strip and other materials are used to seal it in advance, which ensures the smooth progress of the casting construction. While sealing the gap of the sealing structure, the sealing strip and other materials can also be used to apply glue for secondary sealing to improve the sealing performance and effectively prevent unnecessary leakage of low-temperature epoxy materials. The sealing strip and other materials are usually removed after the low-temperature epoxy material is cast.

[0176] It is worth mentioning that in the epoxy casting method for the installation of pressure timber and support structure of LNG fuel tank, the low-temperature epoxy resin can be JM-98L. First, the B component of JM-98L epoxy putty is poured into the A component. The material is mixed at a low speed and uniformly using a deaerator to achieve uniform color between the two components A and B without any color difference.

[0177] Then, after stirring, let it stand for a few minutes to allow the air bubbles in the adhesive to dissipate.

[0178] Finally, pour the mixed adhesive into the pump inlet funnel, start the grouting pump to pump the mixed adhesive into the grouting area until adhesive overflows from the vent.

[0179] The second embodiment of the present invention provides an installation method for LNG fuel tank pressure-bearing timber and a method for casting cryogenic epoxy material thereon. The difference from the first embodiment is that, in the construction process of the fuel tank support portion of the vertical support and the pressure-bearing timber, it further includes a step of applying cryogenic epoxy material to the cavity of the fuel tank support portion 5 of the vertical support by an operator. The cryogenic epoxy material is applied according to a pre-installed thickness. Compared to directly applying the cryogenic epoxy material to the surface of the pressure-bearing timber, this embodiment uses a bottom-brushing process on the cavity of the fuel tank support portion 5 of the vertical support. The application of the cryogenic epoxy material is done in a zigzag pattern at the bottom of the cavity. The cryogenic epoxy material used in this embodiment... The epoxy coating process avoids problems such as moisture loss and material failure due to sunlight exposure during direct coating on the pressure wood surface. The bottom-brushing process utilizes the relatively stable environment of its open bottom to maintain the moisture of the low-temperature epoxy material and avoid sunlight exposure. Furthermore, the bottom-brushing process uses the baffle of the fuel tank support section 5 of the vertical support as a lateral support structure for the low-temperature epoxy material. After the pressure wood enters the cavity, it can quickly compress the low-temperature epoxy material downwards along the inner side of the baffle. At this time, the baffle can act as a guide structure to push the material to the theoretical thickness of the cavity bottom (i.e.,...). Figure 20 The fuel tank support portion 5 of the vertical support directly opposite the upper surface of the middle pressure timber. After applying the low-temperature epoxy material, the pressure timber located directly below the fuel tank support portion 5 of this vertical support is lifted using a lifting trolley (lifting tool trolley) to a position as shown. Figure 20 As shown, after the pressure-bearing timber is pushed into the fuel tank support portion 5 of the vertical support by the lifting trolley, different fixing bolts 20 are set on the baffle 7 of the fuel tank support portion 5 of the vertical support. Two bolts are set on the long side baffle 7 of the fuel tank support portion 5 of the vertical support, and only one bolt is set on the short side baffle 7 of the fuel tank support portion 5 of the vertical support. The pressure-bearing timber is then fixed again using the bolts.

[0180] Before lifting the pressure timber, bolts for fixing the pressure timber are installed at baffle 7, and the pressure timber needs to have corresponding bolt holes pre-drilled at preset positions using a drilling device. The construction process of the fuel tank support section of the vertical support and the pressure timber also includes a pre-installation step of the pressure timber. First, the pressure timber (also called pressure timber blocks; the dimensions of the pressure timber in each part of this invention are arranged according to preset requirements) is transported to the specific installation position using a lifting trolley. The pressure timber is pre-installed, and the final installation height of the pressure timber is adjusted based on the benchmark level. Any interference is checked, and the adjustment bolts are marked on the pressure timber at the positions of the bolt holes on the baffle (enclosure). A gap is ensured between the pressure timber and the structural enclosure; it should not be tightly fitted to avoid glue residue. The final installation positioning of the pressure timber is also marked. Then, the pressure timber is removed from the cavity of the fuel tank support section 5 of the vertical support. Adjustment bolt holes are drilled at the marked positions on the pressure timber. For example, an outer diameter of 29mm and a depth of 20-25mm are selected. Before drilling, the pressure timber itself needs to be checked for integrity and absence of cracks. The state of the bolts in the fixed state can be seen in [reference needed]. Figure 21 After the low-temperature epoxy material is applied and positioned, the saddle is lifted into place according to the final positioning marks on the bearing timber. If epoxy material overflows from the perimeter of the bearing timber, it indicates that the low-temperature epoxy material has filled the interior of the saddle. Adjusting bolts are then screwed into the bearing timber blocks to secure them. A jack is used to support the fixed position. The saddle is removed after the low-temperature epoxy has completely cured. During the epoxy curing process, the ambient temperature must be monitored and must not be lower than 13 degrees Celsius.

[0181] For cleaning the surface of the pressure-bearing wood, the epoxy resin casting area is cleaned with a cloth and a cleaning agent (acetone). In this invention, manually applying the low-temperature epoxy resin material is also part of the casting process. Furthermore, in each construction process step, the low-temperature epoxy resin also includes a sample collection step. In this step, a 100mm*100mm*50mm metal box (2mm thick) is used to package the low-temperature epoxy resin material for different steps. The epoxy resin is sampled on-site and preserved for subsequent testing.

[0182] The third embodiment of the present invention provides an installation method for pressure-bearing timber in an LNG fuel tank and a method for casting it with cryogenic epoxy material. The difference between this embodiment and the first embodiment is that... (See details below). Figure 22 In the process of vertical support bearing wood epoxy casting, when the four corner vent holes of stainless steel pad plate 13 are sealed with sealant, a dynamic release device 21 is installed here. When the pressure of pumping low temperature epoxy material exceeds the preset value, the dynamic release device 21 will destroy the pressure relief membrane and release the pressure to the outside through this device.

[0183] The dynamic release device has a release rod portion 21a, which has a lower channel 21b and an intermediate chamber 21c located at the upper end of the lower channel. An upper channel is also provided in the release rod portion above the intermediate chamber 21c. At least two pressure-relieving membranes 21d are provided in the intermediate chamber 21c; in this embodiment, two layers are provided. A flared support 21e is provided in the upper channel near the intermediate chamber. A dynamic pressure-relieving rod 21f is installed in the upper channel. The top of the dynamic pressure-relieving rod 21f has an operating handle 21g, and the bottom of the dynamic pressure-relieving rod has... A circular block 21h is located at the flared support. This circular block has a horizontal opening 21i, identical to the hollow channel of the dynamic pressure relief rod. A release port is located at the top of the operating handle or the dynamic pressure relief rod. In this embodiment, the operating handle is an elliptical hollow structure. A release port 21j is arranged on the side of the operating handle. A normally closed movable cavity 21k is located at the upper part of the release rod. An annular protrusion is located at the normally closed movable cavity of the dynamic pressure relief rod 21f. A spring 21l, with one end connected to the annular protrusion, is located within the normally closed movable cavity. Figure 23 The device is in a non-working state as shown, and the pressure relief membrane is not in working state at this time.

[0184] When pumping low-temperature epoxy material begins, the operator presses down the operating handle 21g. At this time, the inner channel of the dynamic pressure relief rod 21f is connected to the space where the low-temperature epoxy material needs to be poured through the horizontal opening of the circular block. The dynamic release device 21 is in a working state. During the low-temperature epoxy pouring process, when the pumping pressure exceeds the preset value, the pressure relief membrane 21d will break, and the low-temperature epoxy material will overflow from the release port 21j of the operating handle, thus completing the pressure relief step simultaneously.

[0185] The fourth embodiment of the present invention provides a method for installing pressure-bearing timber in an LNG fuel tank and casting it with cryogenic epoxy material. The difference between this method and the first embodiment is that the cup-shaped seats 3 of the lifting trolley used in each step are arranged in two rows and two columns on the lifting trolley. (See [reference]). Figure 24 The lifting trolley has two vertical adjustment rails 1a and two horizontal adjustment rails 1b located between the vertical adjustment rails. The bowl-shaped seat can move along the corresponding adjustment rails. The bottom of the bowl-shaped seat is equipped with sliding support feet that match the vertical and horizontal adjustment rails. The bowl of the bowl-shaped seat has locking bolts 1c distributed at its bottom. The locking bolts 1c pass through the bottom of the bowl-shaped seat and are equipped with rubber sleeves (if liquid is placed inside the bowl-shaped seat, it can achieve a sealing effect and prevent leakage). When the locking bolts are pressed against the upper surface of the adjustment rails, the bowl-shaped seat can be kept from moving. It is worth mentioning that the inner side wall of the bowl of the bowl-shaped seat is provided with an annular horizontal line 1d. When liquid (such as water) is placed in the bowl of the bowl-shaped seat, it is observed whether the upper surface of the liquid coincides with the annular horizontal line 1d to determine whether the lifting trolley is in a horizontal state, thereby improving the accuracy of the pressure wood installation and the efficiency of construction.

[0186] It should be noted that multiple high-pressure air holes 1e are arranged in a regular pattern on the transverse adjustment rail, such as the two rows and two columns of high-pressure air holes shown in the figure. These high-pressure air holes are connected to a purging air source such as a high-pressure gas cylinder. Alternatively, a small high-pressure gas cylinder and the corresponding control solenoid valve can be installed at the bottom of the trolley. When the pressure wood is placed on the lifting fixture trolley, the lower surface of the pressure wood will be continuously purged by high-pressure gas to prevent dust and other impurities from adhering. When the lifting fixture trolley is not placed on the pressure wood, it is located below the corresponding base. After the lifting fixture trolley is raised and pushed into the baffle cavity of the corresponding support, impurities such as those at the bottom of the fuel tank are purged by high-pressure gas. The levelness of the fuel tank can be observed by observing the state of the liquid inside the lifting fixture trolley. At this time, a transparent material can be set at the annular horizontal line position of the cup-shaped seat for easy observation. With the high-pressure air vents configured, there is no need to place a pad on the lifting trolley. Instead, the pressure-bearing wood can be directly installed on the bowl-shaped seat. A 3cm wide wooden ring can be set on the upper edge of the bowl-shaped seat. This wooden ring serves two purposes: first, it can cause liquid to surge and overflow from the bowl during the lifting and moving of the trolley; second, it can increase the stress-bearing surface and prevent stress concentration from damaging the pressure-bearing wood.

[0187] The equipment provided in this embodiment can effectively improve work efficiency while simultaneously enhancing the accuracy of construction.

[0188] In this embodiment, the low-temperature epoxy material used for shore foundation construction is PHILLYMASTIC TG-7B low-temperature epoxy material (for brushing) from Yigong Polymer (Wujiang) Co., Ltd., and the low-temperature epoxy material used for interior construction of the ship's cabin is EPOCAST 36-P low-temperature epoxy casting material (for pumping) from Yigong Polymer (Wujiang) Co., Ltd.

[0189] The fifth embodiment of the present invention provides an installation method for pressure-bearing timber in an LNG fuel tank and a method for casting cryogenic epoxy material thereon. The difference between this embodiment and the first embodiment is that, see [link to first embodiment]. Figure 25 and Figure 26 The shore foundation construction process includes a temperature control system (using the temperature control system for temperature control), which includes an insulated shed 201, installed in the epoxy material construction area.

[0190] The low-temperature epoxy material used is PHILLYMASTICTG-7B low-temperature epoxy material from Yigong Polymer (Wujiang) Co., Ltd.

[0191] The temperature control system is located in the epoxy material construction area (inside the insulation shed) and includes at least one temperature sensor 202, at least one heating fan 203 and a control module 204. The temperature sensor 202 and the heating fan 203 are both connected to the control module 204.

[0192] When the temperature sensor detects a temperature below 13℃, the control module controls the heating fan to work; when the temperature sensor detects a temperature above 35℃, the control module controls the heating fan to stop working.

[0193] This invention can provide a suitable temperature environment for the installation of pressure-bearing timber in fuel tanks (in conjunction with epoxy material, the bottom of the fuel tank is coated with epoxy material, and the pressure-bearing timber is installed to the area where the bottom of the fuel tank is coated with epoxy material) (facilitating construction in low-temperature environments) and improving construction results.

[0194] In this embodiment, the insulated shed 201 includes columns 201a distributed at the four corners. Lateral support sections (not shown in the figure) are provided between adjacent columns 201a. The lateral support sections and columns form a support frame. The lateral support sections can be designed as needed or refer to existing technologies. A top cover 201b is provided on the top of each column 201a, and side panels 201c are provided on the sides of each column 201a. At least one side panel has an opening and closing door. The opening and closing door facilitates the entry and exit of personnel and materials (large components such as fuel tanks are pre-placed in the construction area; after the insulated shed is completed, it will be hoisted to the construction area, covering these components). Simultaneously, when closed, the internal space is relatively sealed to facilitate insulation. The insulated shed covers the epoxy material construction area, facilitating insulation work and reducing the impact of the external environment on the epoxy material construction area. Notably, a lifting ring (not shown in the figure, the bottom of the lifting ring passes through the top cover and connects to the column) can be provided at the top of each column. The insulation shed can be easily hoisted (to or away from the epoxy material construction area) using four lifting rings, which facilitates construction.

[0195] In this embodiment, the temperature sensor 202 is arranged on a tabletop 205 with four legs. The top of the tabletop 205 is 20-30 cm above the plane where the bottom of the fuel tank 200 is located. The control module 204 is arranged on the tabletop 205. The joint between the pressure timber and the fuel tank has a certain height off the ground (the fuel tank is suspended by a support). Due to the characteristics of hot air, the upper space temperature is easily higher than the lower space temperature. The above design can improve the accuracy of overall space temperature measurement (especially temperature measurement at the height where the pressure timber and the fuel tank are joined).

[0196] In this embodiment, two heating fans (which do not interfere with each other's operation) and two temperature sensors are installed at each fuel tank 200. When either temperature sensor detects a temperature value less than 13°C, the control module controls the heating fan to operate; when either temperature sensor detects a temperature value greater than 35°C, the control module controls the heating fan to stop operating. A reasonable arrangement of the heating fans and the number of temperature sensors can improve the temperature control effect. 13-35°C is the ideal temperature range for epoxy material application. If any temperature sensor detects a temperature value deviating from this range, the temperature control device will activate (start or stop operating), improving system agility. The arrangement of multiple temperature sensors can improve the reliability of the device.

[0197] See Figures 27-33 The heating fan is installed (placed on the disc of the sweeping mechanism, described below) at the sweeping mechanism 206. The sweeping mechanism 206 has a U-shaped base 206a, a mounting platform 206b is set inside the base 206a, a bearing 206c is installed at the mounting platform 206b, a vertical shaft 206d is installed at the bearing 206c, and a shaft gear 206e is set on the vertical shaft 206d. The shaft gear 206e is driven by a motor, which is mounted on the mounting platform. The motor can rotate in both forward and reverse directions (the forward and reverse rotation angles can be adjusted according to actual needs). It is determined that the motor can refer to the existing technology), and a disc 206f (which can be made of stainless steel or other materials) is set at the top of the vertical shaft 206d. Multiple hemispherical recesses are arranged at equal intervals around the top of the base 206a (three hemispherical recesses in this embodiment). Stainless steel beads 206g are arranged in the recesses (correspondingly, three beads in this embodiment). The lower side of the disc and the beads cooperate (the outer side of the disc is supported by the beads, and the beads can move in the hemispherical recesses during rotation to assist the disc rotation. Lubricating oil is added to the hemispherical recesses as needed).

[0198] The disc 206g and the vertical shaft 206d are connected by several connectors (two connectors in this embodiment, one on the left and one on the right of the vertical shaft). Each connector has a first rod 206j located on the lower side of the disc. Several inclined limiting bodies 206k are arranged circumferentially at the bottom of the first rod 206j (the inclined limiting bodies are made of stainless steel, are sheet-like, and are arranged at equal intervals circumferentially at the bottom of the first rod, and the number can be three, four, five, or more). A first plate 206l is arranged at the top of the vertical shaft 206d, and a first plate through hole is provided on the first plate 206l. After the first rod 206j and the inclined limiting bodies 206k pass through the first plate through hole, the inclined limiting bodies 206k unfold to limit their movement. A planar structure 206p is provided on one side of the vertical shaft 206d, and a structural notch 206q is provided in the middle of the disc 206f.

[0199] Place the disc above the base, aligning the structural notch with the vertical axis (the vertical axis's planar structure faces backward, and the disc's structural notch faces backward; using the vertical projection as a reference, align the straight line at the front of the structural notch with the vertical axis's planar structure; at this point, the structural notch and the vertical axis are aligned, the first rod on the left and the first plate's through hole are aligned, and the first rod on the right and the first plate's through hole are aligned). Lower the disc, supported by the ball bearings. Insert the first rod into the corresponding (directly below) first plate's through hole. The inclined limiting body enters the first plate's through hole and folds. Pressing the central area of ​​the disc causes a certain deformation in that area, allowing the inclined limiting body to pass through the first plate's through hole (when the disc is supported by the ball bearings, the top part of the inclined limiting body is still placed inside the first plate's through hole). After passing through, unfold it, and the inclined limiting body provides a limit (at this point, the central area of ​​the disc is not under force and reset). After installation, fix the disc and the vertical axis, while simultaneously providing auxiliary limiting for the ball bearings. The fixing method of the connector avoids the adverse effects on the mounting disk caused by the free rotation of the vertical shaft, and achieves a good connection between the disk and the vertical shaft, as well as limiting the position of the ball part.

[0200] Due to the presence of the vertical plane, lubricating oil can be added through the structural opening. The lubricating oil can flow downward along the vertical plane to the bearing for lubrication (there is an oil groove on the base below the bearing, which can accumulate lubricating oil, and the accumulated lubricating oil lubricates the bearing), which is beneficial for maintenance.

[0201] The motor drives the shaft gears in both forward and reverse directions. When the motor rotates forward, it causes the disk to rotate to one side by a certain angle (towards...). Figure 31 For example, the disc rotates 90 degrees clockwise (the specific angle can be set as needed), and after reaching the desired position, the motor stops and then rotates in the opposite direction, causing the disc to rotate a certain angle towards the other side (for example, ...). Figure 31 For example, the disc can rotate 90 degrees counterclockwise (the specific angle can be set as needed), and then stop when it reaches the desired position, repeating this process. This method allows the heating fan to perform air oscillation, improving the heating effect of the space (area) and enhancing the construction efficiency. It also improves the heating effect and applicability of ordinary industrial heating fans (which do not have an oscillating air oscillation function).

[0202] Unless otherwise specified, the orientations in this embodiment, such as front, back, left, and right, are indicated by the arrows in the attached drawings.

[0203] In this embodiment, an outer convex ring 206h and an inner convex ring 206i are respectively provided on the outer and inner sides of the top of the base 206a. The top heights of the outer convex ring 206h and the inner convex ring 206i are the same, and the top height of the outer convex ring 206h is less than the top height of the bead 206g. A top convex ring 206m (the whole is a ring-shaped body) is provided on the outer periphery of the bottom of the disc 206f. The top convex ring 206m and the outer convex ring 206h are fitted together (the top convex ring can be inserted into the outer convex ring). The left side of the top convex ring 206m (the left half of the top convex ring) is provided with a left air hole 206n, and the inlet of the left air hole 206n faces the left rear. The right side of the top convex ring 206m (the right half of the top convex ring) is provided with a right air hole 206o, and the inlet of the right air hole 206o faces the right rear.

[0204] There is a possibility of lubricating oil overflow at the hemispherical recess, and a possibility of dripping after excessive lubricating oil comes into contact with the disc and the ball. The space between the two convex rings prevents lubricating oil located at the top of the base from overflowing and / or dripping and affecting the surrounding area (e.g., safety hazards, potential contamination of components). The cooperation between the top and outer convex rings reduces or prevents external foreign objects from entering the sweeping mechanism from between the disc and the top of the base, thus avoiding adverse effects (affecting the operation of the internal structure). Simultaneously, the left and right vents on the top convex ring allow for ventilation, facilitating heat dissipation for components within the sweeping mechanism (e.g., the motor). See [link to relevant documentation]. Figure 31 When the disc rotates clockwise, the air intake through the left vent is more effective; when the disc rotates counterclockwise, the air intake through the right vent is more effective, resulting in better ventilation. Because the top protruding ring is inserted into the outer protruding ring, it provides lateral restraint to the disc, preventing damage to the connecting parts from lateral impacts.

[0205] Notably, the top height of the vertical axis 206d is greater than the top height of the base but less than the top height of the ball. This design prevents damage caused by excessive deformation during disc installation and also facilitates alignment due to its proximity to the structural notch.

[0206] The outer diameter of the shaft gear is larger than that of the bearing. The shaft gear can provide some protection for the bearing.

[0207] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. The installation of pressure-bearing timber for the vertical support of the LNG fuel tank and the epoxy casting process for the vertical support, characterized in that, The installation process for the vertical support bearing timber includes: The installation of the vertical support pressure timber is carried out after the fuel tank insulation is laid and before the fuel tank is hoisted, and includes the following steps: Before installing the pressure timber, remove rust, welding slag, and oil stains from the inner surface of the bottom support baffle. After cleaning, apply anti-rust paint. Inspect the flatness and levelness of each vertical support at the bottom of the fuel tank, as well as the installation accuracy of the support baffles; After the pressure timber is lifted into place using a lifting trolley, it is coated with low-temperature epoxy material for installation. The pressure timber is then secured to the fuel tank support using bolts coated with grease, through pre-drilled M20mm tapped threaded holes on the pressure timber and φ22mm holes on the left and right flat steel of the fuel tank support. After all the pressure timbers for the fuel tanks are installed in place, the flatness and levelness of the lower surface of the pressure timbers are measured according to the preset requirements, and the data are recorded as a reference for the lifting and positioning of the fuel tanks. After all the pressure timber installation measurements were completed, the outer surface was covered with plastic film, ready for the fuel tank to be hoisted. The epoxy casting process for vertical supports includes: Before the fuel tank is hoisted and positioned, the rust, rust spots, welding slag, and oil stains on the inner surface of the inner bottom support should be cleaned and coated with a layer of anti-rust paint with a film thickness not exceeding 30um. Draw the stainless steel plate installation positioning line on the inside side of the inner bottom support plate; Tighten the bolts through the pre-drilled tapped thread holes in the inner bottom support plate to the approximate installation height required for the stainless steel pad, 15mm from the inner surface of the support base plate. Place the stainless steel pad on the pre-tightened support base plate bolts, and position the stainless steel pad by adjusting the height of the bolts so that its upper surface is flush with the surrounding plate. After the fuel tank is hoisted and positioned, remove the bolts on both sides of the fuel tank support baffle used to fix the pressure wood, so that the pressure wood and the stainless steel pad are firmly attached. If the stainless steel pad is not firmly attached, adjust the bolts on the support base plate to make it firmly attached to the pressure wood. Apply grease to the stainless steel backing plate; cleaning is carried out after the epoxy has cured. Seal the area around the four corner vents of the stainless steel pad with sealant to prevent epoxy resin from overflowing. Also seal the gap between the stainless steel pad and the support baffle with epoxy resin. Epoxy resin is poured through the pre-drilled pouring hole on the support base plate. The pouring of epoxy resin is observed through the four vent holes at the corners of the stainless steel pad until the epoxy resin overflows from the vent holes of the stainless steel pad, at which point the pouring port ball valve is closed. After the epoxy resin is poured, a tube is inserted into one of the vent holes to replenish the epoxy resin, so that the epoxy liquid inside the support is completely filled. During the epoxy resin curing period, the epoxy resin seal must not be damaged, and the pouring port ball valve must not be opened. After the epoxy has fully cured, remove the sealant from the stainless steel pad and remove the lifting bolts under the support base plate. Fill the openings of the lifting bolts with epoxy putty, and retain the ball valve at the pouring port.

2. The installation of the LNG fuel tank vertical support pressure timber and the epoxy casting process for the vertical support according to claim 1, characterized in that, The thickness of the stainless steel pad is 10mm.

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