Special recombined material for independent liquid cargo tanks of LNG, LPG and LEG ships and manufacturing method of special recombined material

Abstract

The invention provides a special recombinant material applied to the fields of liquefied petroleum gas (LPG), liquefied ethylene gas (LEG), liquefied natural gas (LNG) A / B / C type independent liquid cargo tanks and part of low-temperature pipeline supports and a manufacturing method of the special recombinant material. The invention provides a manufacturing method of a special recombined material for the ultralow-temperature field. The manufacturing method comprises the steps of selection of a veneer tree species and an adhesive, determination of the thickness of a veneer and the adhesive applying amount, and rapid gum dipping and hot pressing of a thick veneer. According to the manufacturing method provided by the invention, the vacuum high-pressure impregnation adhesive is adopted, so that the effects of high impregnation efficiency, large impregnation amount and uniform resin distribution can be realized; and a temperature sensor and a pressure sensor are installed, so that early warning can be carried out in advance when abnormity occurs. The special recombinant material has excellent mechanical properties such as water resistance, compression resistance, bending resistance and shearing resistance at room temperature and ultralow temperature (-163 DEG C). The special recombinant material provided by the invention can be used for liquid cargo hold pressure-bearing wood of LPG, LEG and LNG ships and part of low-temperature pipeline brackets.

Description

Technical Field

[0001] The present invention belongs to the technical field of wood, and in particular, provides a special recombinant material for independent liquid cargo tanks of LNG, LPG and LEG ships and a manufacturing method thereof. Background Art

[0002] There are two main types of LNG carriers on the market: one is the membrane type (main type GTT NO96, GTTMark Ⅲ), which is generally a large ship of more than 100,000 cubic meters, accounting for about 70%-80% of the global LNG carrier market; the other is the independent type, which is divided into type A, type B and type C, of ​​which type C is more widely used. The main types of tanks used in existing large LNG ships do not require cargo hold supports. The C-type independent liquid cargo tank system is supported by supports for horizontally and longitudinally arranged cargo tank containers. During the voyage of the ship, the support will bear the weight inertia force from the cargo hold container and the weight of the loaded liquid cargo and the weight in various acceleration directions. The concentrated force is large and the stress state is very complex. At the same time, due to the loading of extremely low-temperature liquid cargo, the support is in a low-temperature environment and the material is prone to low-temperature brittle failure. Therefore, as the supporting structure of the liquid cargo tank, the support structure will directly affect the safety of the liquid cargo tank in navigation.

[0003] The invention application with publication number CN114857486A discloses a support block for storing a tank for cryogenic liquid in a ship, the cryogenic liquid is particularly liquefied gas, LNG, LPG, ethylene, etc. The support block is formed by dense laminated wood, the dense laminated wood is formed by veneers, the veneers are impregnated with synthetic resin and stacked, and the stack is subsequently densified at high temperature to form the dense laminated wood, the support block forms a support side facing the tank body so as to be connected to the tank body, and a gap is formed in the support side of the dense laminated wood, the gap extends substantially orthogonally to the support side, and the gap is filled with aerogel. Wherein, the veneer is maple, birch or European beech. The invention also points out that the complete impregnation of the veneer can be achieved by vacuum impregnation, and at the same time, it is also pointed out that the surface of the dense laminated wood and / or the veneer can be processed, in particular polished and / or planed, to ensure the absorption effect and efficiency of the synthetic resin, but such a process has the problem of complex process and no warning before damage. Summary of the invention

[0004] In order to solve the above complex technical problems, a method for manufacturing special recombinant materials for ultra-low temperature is provided, including the selection of tree species and adhesives, the determination of veneer thickness and glue application amount, and the rapid glue dipping and hot pressing process of thick veneers.

[0005] The present invention adopts vacuum high-pressure impregnation adhesive, which can achieve the effects of high impregnation efficiency, large impregnation amount and uniform resin distribution; and the raw materials can be directly impregnated with adhesive after being processed into boards / blocks, eliminating surface processing steps (such as polishing and / or planing), and the process is simple.

[0006] In some embodiments of the present invention, the thick veneer is obtained by rotary cutting of one or more of beech, birch, poplar, sibiricus, maple, catalpa, and eucalyptus, and has a thickness of 0.5-4 mm. The raw material with rich pore structure further provides a material basis for improving the impregnation amount and impregnation efficiency; combined with vacuum high-pressure impregnation and low molecular weight adhesive, it not only realizes a simple process, but also can improve the impregnation efficiency, impregnation amount and resin distribution uniformity at a relatively low high pressure.

[0007] In some embodiments of the present invention, the adhesive is selected from one or more of phenolic resin, epoxy resin, melamine resin, phenolic-epoxy resin, and epoxy-polyamide.

[0008] The molecular weight of the adhesive affects the effect of the adhesive penetrating into the wood. If the molecular weight is too large, it is not easy to penetrate into the wood. The low molecular weight adhesive used in the present invention is easy to impregnate the wood, providing a material basis for high impregnation amount and impregnation efficiency, further improving the impregnation efficiency and effect. Combined with vacuum high-pressure impregnation, it can not only achieve a simple process, but also further increase the impregnation amount and improve the impregnation efficiency; at the same time, the mechanical properties of the reconstructed material obtained are good. The low molecular weight adhesive used in the present invention achieves a balance between impregnation effect and mechanical properties.

[0009] In some embodiments of the present invention, the amount of adhesive applied is 15-35% based on the weight of the thick veneer.

[0010] In some embodiments of the present invention, the amount of adhesive applied is 20-30% based on the weight of the thick veneer.

[0011] On the basis of adopting low molecular weight adhesive, the present invention controls the sizing amount to 15-35%, especially 20-30%, and realizes high mechanical strength and high water resistance through high density and high sizing amount.

[0012] In some embodiments of the present invention, the conditions for rapid dipping of thick veneer are: firstly maintaining a negative pressure of 0.05-0.10 MPa for 5-10 min, and then maintaining a positive pressure of 1.0-1.3 MPa for 15-60 min.

[0013] In some embodiments of the present invention, the thick veneer after impregnation and drying is assembled orthogonally, parallelly or at a certain angle (that is, it can be assembled at any angle, such as 0-30°, 30-60°, 60-90°), and then processed into a reconstituted material by hot pressing; wherein the hot pressing process is: press closing time 5 minutes, maximum cylinder pressure 10 Mpa, hot pressing temperature 140°C, hot pressing time 1°C / min, after the hot pressing is completed, cool to <60°C with cold water and unload the plate.

[0014] In particular, in order to improve the functionality of the special recombinant material, the manufacturing method of the special recombinant material further includes installing one or more of a temperature sensor, a pressure sensor, and a stress sensor, wherein one or more of the temperature sensor, the pressure sensor, and the stress sensor are embedded in the special recombinant material, and / or arranged on the surface of the special recombinant material away from the side that is subjected to pressure (i.e., away from the side of the liquid cargo tank). It may also further include an alarm, which is arranged on the surface of the special recombinant material and can be observed. The alarm is connected to the temperature sensor and / or the pressure sensor and receives the temperature and / or pressure signal from the temperature sensor and / or the pressure sensor. When at least one of the temperature, pressure, and stress signal is greater than a set value, the alarm sends an alarm signal; preferably, the alarm signal includes a light alarm and / or a sound alarm. The alarm can be connected to the electronic device of the staff, transmit the alarm signal to the electronic device, and send the alarm signal on the electronic device, so that the staff can observe and find the use of the special recombinant material in time, and can replace it in time or take other measures.

[0015] As a second aspect of the present invention, there is provided a special recombinant material for ultra-low temperature use, which is manufactured using the aforementioned method for manufacturing the recombinant material.

[0016] The special recombinant material for ultra-low temperature obtained by the present invention can be used as pressure-bearing wood of liquid cargo tanks of cryogenic liquid transport ships, wherein the cryogenic liquids are liquefied natural gas (LNG), liquefied petroleum gas (LPG), liquefied ethylene gas (LEG), etc.; the liquid cargo tank can be type A, type B or type C, especially type C liquid cargo tank.

[0017] The present invention has the following beneficial effects: (1) The impregnation of adhesive is carried out in a vacuum and high-pressure environment, which can accelerate the penetration of adhesive into wood. The raw materials can be directly impregnated with adhesive after being processed into boards / blocks, eliminating the surface processing steps (such as polishing and / or planing). The process is simple and can also improve the impregnation efficiency and impregnation amount; (2) Using low molecular weight adhesive to impregnate wood provides a material basis for high impregnation amount and efficiency, further improving the impregnation efficiency and effect. Combined with vacuum high pressure impregnation, it can not only achieve a simple process, but also further increase the impregnation amount and improve the impregnation efficiency; (3) High mechanical strength and high water resistance are achieved through high density and high sizing amount; (4) The wood raw material used has excellent material properties (high density and hardness), low water absorption and low thermal conductivity, and can play a good role in thermal insulation. In addition, the wood has a rich pore structure, and the adhesive can easily penetrate into the wood during the adhesive impregnation process. Combined with vacuum high-pressure impregnation and low molecular weight adhesive, the process is simple and the impregnation efficiency and impregnation amount can be further improved. (5) The special recombinant material (plate / block) provided by the present invention may further include a sensor (such as a temperature sensor, a pressure sensor, a stress sensor, etc.) and an alarm, which can facilitate the staff to timely observe and discover the use of the special recombinant material, and can replace it or take other measures in time, thereby improving the functionality of the special recombinant material; (6) The special recombinant material obtained by the present invention has excellent mechanical properties such as compression resistance, bending resistance, and shear resistance at room temperature and ultra-low temperature (-163°C). DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme in the present invention will be clearly and completely described in combination with specific implementations. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The raw materials involved in the following embodiments are all commercially available.

[0019] Example 1

[0020] A method for manufacturing a special recombinant material for ultra-low temperature, comprising the following steps: (i) The beech wood is peeled into 0.5-4.0 mm thick veneer; or in some application scenarios, the beech wood can be processed into blocks as needed; (ii) impregnate the low molecular weight phenolic resin adhesive into the interior of the veneer by vacuum high pressure impregnation: maintain negative pressure of 0.09 MPa for 5-10 min, maintain positive pressure of 1.2 MPa for 15-60 min, and control the amount of glue applied to 25%; (iii) drying the impregnated veneer to a moisture content of 8-12%; (iv) adopting orthogonal assembly and processing into the special recombinant material through hot pressing; hot pressing process: press closing time 5 minutes, maximum cylinder pressure 10 Mpa, hot pressing temperature 140°C, hot pressing time 1°C / min, after hot pressing, cool to <60°C with cold water and unload.

[0021] In this embodiment, the obtained special recombinant material can be used as pressure-bearing wood of liquid cargo tanks in ships transporting liquefied natural gas (LNG), especially C-type liquid cargo tanks, and can also be used in any other parts of the ship that may be needed.

[0022] Beech wood has high density, high hardness and rich pore structure, and small molecular weight phenolic resin is used as adhesive, which provides the material basis for high impregnation amount and impregnation efficiency; the vacuum high pressure impregnation process is used to improve the impregnation efficiency, impregnation amount and resin distribution uniformity; high mechanical strength and high water resistance are achieved through high density and high glue application amount.

[0023] The density of the special recombinant material obtained in this example is 1.3-1.4 g / cm 3 , water absorption (20℃) ≤0.5%, thermal conductivity ≤0.32 W / (m•K), excellent mechanical properties such as compression, bending and shearing at room temperature and ultra-low temperature (-163℃). The compressive strength perpendicular to and parallel to the layers can reach 245 MPa and 178 MPa respectively, the shear strength is 59.2 MPa, the static bending strength perpendicular to and parallel to the layers can reach 172 MPa and 142 MPa respectively, and the elastic modulus perpendicular to and parallel to the layers can reach 15.8 GPa and 15.4 Gpa respectively.

[0024] Example 2

[0025] The present embodiment provides a special recombinant material for pressure-bearing wood of LNG ships, and its manufacturing method is basically the same as that of Example 1. The only difference is that, in this embodiment, in order to further improve the functionality of the pressure-bearing wood, it also includes installing a sensor on the special recombinant material for pressure-bearing wood of Example 1, and the sensor is installed on the side surface of the pressure-bearing wood away from the liquid cargo tank.

[0026] In this embodiment, the sensor may be a temperature sensor, a pressure sensor, or a stress sensor. Of course, if you want to monitor the temperature, pressure, and stress inside the pressure-bearing wood, you can also embed the sensor inside the pressure-bearing wood if conditions permit.

[0027] In order to enable the staff to observe and discover the use of the pressure-bearing wood in time, an alarm can also be included. The alarm is connected to the sensor and receives signals from the sensor, such as at least one of temperature, pressure, and stress signals. The signal setting value can also be set, and when at least one of the temperature, pressure, and stress signals is greater than the set value, the alarm sends an alarm signal, such as a light warning and / or a sound warning.

[0028] When the staff is not near the liquid cargo tank, in order to facilitate the staff to timely observe and discover the use of the pressure-bearing wood, and to replace it or take other measures in time, the alarm can also be connected to the staff's electronic equipment, such as a mobile phone or computer, to directly transmit the alarm signal to the electronic equipment and issue an alarm signal on the electronic equipment.

[0029] The present invention provides a special recombinant material and a method for manufacturing the same. However, since cryogenic liquids have the common property of low temperature, those skilled in the art can expect that the recombinant material obtained by the method for manufacturing the recombinant material of this embodiment is also suitable for pressure-bearing wood when transporting other cryogenic liquids, such as liquefied petroleum gas (LPG), ethylene, liquid oxygen, liquid argon, liquid nitrogen, liquid carbon dioxide, etc.; at the same time, its liquid cargo tank can be type A, type B, or type C.

[0030] The material properties and characteristics of the raw materials will directly affect the impregnation efficiency and impregnation amount, and will also affect the mechanical properties of the final reconstituted material. Since birch, poplar, schima superba, maple, catalpa, eucalyptus and other woods have similar material properties to beech, with greater hardness, greater density, and rich pore structure, the beech in this embodiment can be replaced with birch, poplar, schima superba, maple, catalpa, eucalyptus and other woods, and similar results can be obtained.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing a special recombinant material for ultra-low temperature, characterized in that: It includes the selection of tree species and adhesive, the determination of veneer thickness and glue amount, and the rapid glue dipping and hot pressing process for thick veneers.

2. The manufacturing method according to claim 1, characterized in that: The thick veneer is obtained by rotary cutting from one or more of beech, birch, poplar, safflower, maple, catalpa and eucalyptus, and has a thickness of 0.5-4 mm.

3. The manufacturing method according to claim 1 or 2, characterized in that: The adhesive is selected from one or more of phenolic resin, epoxy resin, melamine resin, phenolic-epoxy resin, and epoxy-polyamide.

4. The manufacturing method according to any one of claims 1 to 3, characterized in that: According to the weight of the thick veneer, the amount of the adhesive applied is 15-35%; preferably, the amount of the adhesive applied is 20-30%.

5. The manufacturing method according to any one of claims 1 to 4, characterized in that: The conditions for the rapid dipping of thick veneer are: firstly maintain a negative pressure of 0.05-0.10 MPa for 5-10 minutes, and then maintain a positive pressure of 1.0-1.3 MPa for 15-60 minutes.

6. The manufacturing method according to claim 5, characterized in that: After being impregnated and dried, the thick veneer is assembled orthogonally and / or parallelly and / or at an angle, and then processed into a reconstituted material by hot pressing; wherein the hot pressing process is: the press closing time is 5 minutes, the maximum oil cylinder pressure is 10 MPa, the hot pressing temperature is 140°C, the hot pressing time is 1°C / min, and after the hot pressing is completed, the plate is cooled to less than 60°C with cold water and unloaded.

7. The method for producing a special recombinant material according to any one of claims 1 to 6, characterized in that: It also includes installing one or more of a temperature sensor, a pressure sensor, and a stress sensor, wherein the one or more of the temperature sensor, the pressure sensor, and the stress sensor are embedded in the special recombinant material, and / or arranged on a side surface of the special recombinant material away from the pressure.

8. The method for producing a special recombinant material according to claim 7, characterized in that: The method also includes installing an alarm, which is arranged on the surface of the special recombinant material in an observable position. The alarm is connected to the temperature sensor and / or the pressure sensor and receives the temperature and / or pressure signals from the temperature sensor and / or the pressure sensor. When at least one of the temperature, pressure and stress signals is greater than a set value, the alarm sends an alarm signal; preferably, the alarm signal includes a light warning and / or a sound warning.

9. The method for producing a special recombinant material according to claim 8, characterized in that: The alarm is connected to the electronic device of the staff, transmits the alarm signal to the electronic device and sends the alarm signal on the electronic device.

10. A special recombinant material for ultra-low temperature, characterized in that: The special recombinant material is produced by the production method of any one of claims 1 to 9.