Heat-preservation sealing anti-corrosion sleeve system for naval vessel pipeline and preparation method of heat-preservation sealing anti-corrosion sleeve system

Abstract

The invention discloses a thermal-insulation sealing anti-corrosion sleeve system for a naval vessel pipeline and a preparation method. The system comprises a nano-antibacterial layer, a polytetrafluoroethylene anti-corrosion cold-resistant layer, a hard polyurethane foaming thermal-insulation layer and a high-density polyethylene protective layer which are sequentially arranged from inside to outside. Oxidation and corrosion in the pipeline are resisted through the nano-antibacterial layer, heat preservation and secondary corrosion prevention are carried out through the polytetrafluoroethylene anti-corrosion cold-resistant layer, invasion of external severe cold is resisted, secondary heat preservation is carried out on the pipeline through the hard polyurethane foaming heat preservation layer with the low heat conductivity, and the corrosion resistance of the pipeline is improved. The integrity of the rigid polyurethane foaming heat preservation layer is guaranteed through the high-density polyethylene protection layer; a co-extrusion molding process is adopted, so that molten material flows of the four materials are co-extruded in a composite machine head to obtain a composite material sleeve; labor and time for adopting a traditional pipe-in-pipe technology can be saved, heat loss caused by the support can be avoided, and pipe bursting, medium condensation and blocking in the low-temperature environment can be avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of pipeline protection, and more specifically, relates to a thermal insulation, sealing and corrosion-resistant casing system and method for ship pipelines. Background Art

[0002] Polar regions attract the attention of countries around the world because of their unique strategic deterrence position, important potential transportation routes and rich natural resources, and ships are one of the indispensable equipment for implementing polar military activities and conducting polar research. When ships sail in the ice areas of polar waters, they face sea ice, extremely low outside temperatures and a series of harsh environmental challenges. The book "Polar Ship Guide" clearly states that the lowest average temperature in the two-level sea areas in winter can reach -38°C. The ship's piping system is exposed to the low temperature environment in the polar region, which is prone to hidden dangers such as pipeline freezing, leakage and corrosion, thereby affecting the safety and stability of the ship's operation. In order to meet the requirements of the high-cold and high-latitude environmental conditions in the polar region, it is particularly important to carry out research on ship pipeline optimization.

[0003] At present, the thermal insulation sleeves of ship pipelines mostly adopt the design structure of filling polyurethane foam in the inner tube and the polyethylene outer protective tube. The main principle is: install a positioning ring on the inner tube that needs to be insulated and anti-corrosion, install it in a high-density polyethylene protective tube, and evenly arrange the brackets in the annular cavity formed between the inner tube and the polyethylene protective tube. The two ends are sealed with flanges, and finally the polyurethane foam is injected into it using a high-pressure foaming machine. Compared with overhead and directly buried thermal insulation pipes, this structure eliminates the engineering damage caused by thermal expansion and contraction and solves the problem of steel corrosion. However, the bracket will cause partial heat loss, and the uneven density of polyurethane foam foaming and the uneven density after molding will affect the thermal insulation performance of the sleeve, which cannot better meet the insulation needs of the sleeve in polar low temperature environments. Under this background technology, it is necessary and practical to optimize the thermal insulation sleeve process. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a thermal insulation, sealing and anti-corrosion casing system and preparation method for ship pipelines, which adopts the co-extrusion integrated molding process of "high-density polyethylene protective layer + hard polyurethane foam insulation layer + polytetrafluoroethylene anti-corrosion and cold-resistant layer + nano antibacterial layer", and the four layers are tightly bonded to form an integral structure of a four-layer insulation casing. Compared with traditional insulation pipes, the casing does not need to install the insulation sleeve on site, saving labor and installation time, and has good wear resistance, corrosion resistance and structural strength; the insulation layer adopts closed-cell foam material, which can effectively block the invasion of external low temperature, and has a low thermal conductivity and good compressive strength; polytetrafluoroethylene has excellent cold resistance, can be used for a long time in a wide temperature range of -180℃ to 260℃, and has outstanding corrosion resistance. The casing can avoid pipe bursting, medium condensation and blockage in low temperature environments, and can effectively solve problems such as pipeline freezing, leakage and corrosion in polar low temperature environments.

[0005] In order to achieve the above-mentioned object, one aspect of the present invention provides a thermal insulation, sealing and anti-corrosion casing system for ship pipelines, comprising a nano antibacterial layer, a polytetrafluoroethylene anti-corrosion and cold-resistant layer, a hard polyurethane foam insulation layer and a high-density polyethylene protective layer arranged in sequence from the inside to the outside in a tubular shape;

[0006] The nano antibacterial layer is used to resist oxidation and corrosion inside the pipeline, the polytetrafluoroethylene anticorrosion and cold-resistant layer is used for heat preservation and secondary anticorrosion to resist the invasion of severe cold from the outside, the low thermal conductivity hard polyurethane foam insulation layer is used to perform secondary heat insulation on the pipeline, and the integrity of the hard polyurethane foam insulation layer is ensured by the high-density polyethylene protective layer, so as to reduce the maintenance cost and replacement cost of the hard polyurethane foam insulation layer and its internal materials;

[0007] The nano antibacterial layer, polytetrafluoroethylene anticorrosive and cold-resistant layer, hard polyurethane foam insulation layer and high-density polyethylene protective layer are formed by a co-extrusion molding process, so that the molten material flows of the above four materials are co-extruded in a composite die to obtain a composite material sleeve; it can avoid heat loss caused by the bracket, and avoid pipe bursting, medium condensation and blockage in low temperature environments.

[0008] Furthermore, the nano antibacterial layer is a nano-scale titanium oxide antibacterial layer.

[0009] Furthermore, the polyurethane foam density used in the rigid polyurethane foam insulation layer is 50Kg / m 3 , the thermal conductivity is 0.0235W / (m·k).

[0010] Furthermore, the high-density polyethylene protective layer is made of high-density polyethylene resin.

[0011] A second aspect of the present invention provides a method for preparing a thermal insulation, sealing and anti-corrosion casing for ship pipelines, comprising the following steps:

[0012] S1: Raw material preparation

[0013] Prepare the raw materials for the nano antibacterial layer, the raw materials for the polytetrafluoroethylene anticorrosive and cold-resistant layer, the raw materials for the rigid polyurethane foam insulation layer, and the raw materials for the high-density polyethylene protective layer;

[0014] S2: Extrusion

[0015] The co-extrusion molding equipment is debugged to the best state to ensure that the molten material flows of each layer can be smoothly co-extruded in the composite die; the raw materials of the nano antibacterial layer, the raw materials of the polytetrafluoroethylene anti-corrosion and cold-resistant layer, the raw materials of the rigid polyurethane foam insulation layer, and the raw materials of the high-density polyethylene protective layer prepared in step S1 are respectively added to the corresponding extruders, and heated to their respective suitable temperatures to fully melt them; the molten material flows of the nano antibacterial layer, the polytetrafluoroethylene anti-corrosion and cold-resistant layer, the rigid polyurethane foam insulation layer, and the high-density polyethylene protective layer pass through the extruder in turn into the composite die; in the composite die, the four molten material flows are co-extruded in the designed order and proportion to form a composite material sleeve after co-extrusion molding;

[0016] S3: Post-processing

[0017] Using water cooling or air cooling to keep the composite sleeve after co-extrusion in the required size and shape during the cooling process, so as to obtain the sleeve after cooling and finalization;

[0018] S4: Traction and cutting

[0019] After cooling and shaping, the sleeve is pulled by a pulling device, and its pulling speed is controlled to match the extrusion speed; during the pulling process, the sleeve is cut according to the predetermined length by a cutting device to obtain the required finished product segment;

[0020] S5: Quality Inspection

[0021] Conduct quality inspection on finished casing to ensure that it meets the design requirements and quality standards;

[0022] S6: Packaging and storage

[0023] Qualified thermal insulation sealing sleeves should be packaged to ensure that they are not damaged during transportation and storage; the packaged thermal insulation sealing sleeves should be stored in a dry, ventilated and cool warehouse, avoiding direct sunlight and high temperature environment to maintain their stable performance.

[0024] Furthermore, the nano antibacterial layer is a nano-scale titanium oxide antibacterial layer.

[0025] Furthermore, the polyurethane foam density used in the rigid polyurethane foam insulation layer is 50Kg / m 3 , the thermal conductivity is 0.0235W / (m·k).

[0026] Furthermore, the high-density polyethylene protective layer is made of high-density polyethylene resin.

[0027] Furthermore, the design of the composite die in step S2 should ensure uniform mixing and tight bonding of the material flows of each layer to avoid stratification.

[0028] Furthermore, the quality inspection indicators for the finished casing in step S5 include dimensional accuracy, interlayer adhesion, and thermal insulation performance.

[0029] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0030] (1) The thermal insulation, sealing and anti-corrosion casing for ship pipelines of the present invention adds nano-silver antibacterial material to the inner layer of the pipeline, which can effectively inhibit the growth of microorganisms such as bacteria and viruses and reduce the harm of harmful microorganisms to the pipeline system. This nano antibacterial layer can maintain excellent antibacterial and mildew-proof properties for a long time, ensuring the hygiene and safety of the pipeline system; the polytetrafluoroethylene (PTFE) used has excellent low-temperature resistance and can maintain good mechanical toughness in liquid nitrogen at -196°C; its corrosion resistance is also excellent and can effectively resist the erosion of various chemicals in the polar environment; by increasing the thickness of the polytetrafluoroethylene layer or using higher purity PTFE materials, the anti-corrosion and cold resistance of the pipeline system can be further improved; polyurethane foam materials with lower thermal conductivity are selected, and advanced foaming technology is used, such as high-pressure foaming machines combined with precise foaming agent ratios and control, to ensure uniform foaming of polyurethane foam and avoid reduced thermal insulation performance caused by uneven density; at the same time, the foamed insulation sleeve is properly post-processed, such as heat treatment or pressure treatment, to further improve its thermal insulation performance and structural stability; high-density polyethylene materials with better flame retardant properties are used to improve the safety of the pipeline system in sudden situations such as polar fires. At the same time, this layer can also play a waterproof role, prevent moisture penetration in the polar environment, and protect the performance of the internal insulation layer.

[0031] (2) The thermal insulation, sealing and anti-corrosion casing system and preparation method for ship pipelines of the present invention adopts a co-extrusion integrated molding process of "high-density polyethylene protective layer + hard polyurethane foam insulation layer + polytetrafluoroethylene anti-corrosion and cold-resistant layer + nano antibacterial layer" to tightly bond the four layers of materials to form an integral structure of a four-layer thermal insulation casing; the casing is protected from oxidation and corrosion inside the pipeline by the nano antibacterial layer, and is insulated and secondary anti-corrosion is performed by the polytetrafluoroethylene anti-corrosion and cold-resistant layer to resist the invasion of severe cold from the outside; the pipeline is secondary insulated by the low thermal conductivity hard polyurethane foam insulation layer, and the The high-density polyethylene protective layer ensures the integrity of the rigid polyurethane foam insulation layer, and reduces the maintenance cost and replacement cost of the rigid polyurethane foam insulation layer and its internal materials; compared with traditional insulation pipes, there is no need to install insulation sleeves on site, which saves labor and installation time, and has good wear resistance, corrosion resistance and structural strength; the insulation layer adopts closed-cell foam material, which can effectively block the invasion of low temperature from the outside, and has a low thermal conductivity and good compressive strength; polytetrafluoroethylene has excellent cold resistance, can be used for a long time in a wide temperature range of -180℃ to 260℃, and has outstanding corrosion resistance. The heat-insulating, sealed and anti-corrosion casing of the present invention can save labor and time when using the traditional "tube in tube" process, can avoid heat loss caused by the bracket, can avoid pipe bursting, medium condensation and blockage in low temperature environment, and can effectively solve the problems of pipeline freezing, leakage and corrosion in polar low temperature environment.

[0032] (3) The method for preparing the thermal insulation, sealing and anti-corrosion sleeve for ship pipelines of the present invention accurately controls the extrusion temperature, pressure and speed of each layer of material during the co-extrusion process to ensure uniform mixing and tight bonding of the material flows of each layer. By optimizing the extrusion process parameters, the quality and performance of the thermal insulation sleeve can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of a heat-insulating, sealing, and anti-corrosion casing for ship pipelines according to an embodiment of the present invention;

[0034] Figure 2 The present invention is a schematic diagram of the preparation process of a thermal insulation, sealing and anti-corrosion casing for ship pipelines according to an embodiment of the present invention.

[0035] In all the drawings, the same reference numerals represent the same technical features, specifically: 1-nano antibacterial layer, 2-polytetrafluoroethylene anti-corrosion and cold-resistant layer, 3-rigid polyurethane foam insulation layer, 4-high-density polyethylene protective layer. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, when an element is referred to as being "fixed to", "disposed on" or "provided on" another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or indirectly connected to the other element; the terms "installed", "connected", "connected" and "provided with" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal connection of the two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0038] like Figure 1 As shown, one aspect of the present invention provides a thermal insulation, sealing and anti-corrosion casing system for ship pipelines, including a nano antibacterial layer 1, a polytetrafluoroethylene anti-corrosion and cold-resistant layer 2, a hard polyurethane foam insulation layer 3 and a high-density polyethylene protective layer 4 which are arranged in sequence from the inside to the outside in a tubular shape; when the temperature of the medium in the pipeline is low, the nano antibacterial layer 1 resists oxidation and corrosion inside the pipeline, and the highly cold-resistant and highly corrosion-resistant polytetrafluoroethylene anti-corrosion and cold-resistant layer 2 performs insulation and secondary anti-corrosion to resist the invasion of severe cold from the outside; secondary insulation is performed by the hard polyurethane foam insulation layer 3 with low thermal conductivity, and the integrity of the polyurethane foam insulation layer is ensured by the outermost high-density polyethylene protective layer 4, reducing the maintenance cost and replacement cost of internal materials. The thermal insulation, sealing and anti-corrosion casing device of the present invention can save labor and time when using the traditional "pipe in pipe" process, avoid heat loss caused by the bracket, and effectively solve the problems of pipeline freezing, leakage and corrosion in polar low temperature environments.

[0039] Furthermore, if Figure 1 As shown, the nano antibacterial layer 1 is located in the innermost layer of the pipeline, and is a nano-level titanium oxide antibacterial layer; the titanium oxide antibacterial layer can adsorb and kill bacteria, viruses and other microorganisms, so that the pipeline automatically decomposes dirt, has antibacterial and self-cleaning functions, and can also resist oxidation and corrosion inside the pipeline, thereby extending the service life of the pipeline.

[0040] Furthermore, if Figure 1As shown, the polytetrafluoroethylene anticorrosion and cold-resistant layer 2 is located on the outside of the nano antibacterial layer 1. Polytetrafluoroethylene (also known as Teflon) has outstanding low-temperature resistance and corrosion resistance. Polytetrafluoroethylene can be used for a long time in a wide temperature range of -180°C to 260°C, is almost insoluble in all solvents, and has the advantages of acid and alkali resistance and resistance to various organic solvents.

[0041] Furthermore, if Figure 1 As shown, the rigid polyurethane foam insulation layer 3 is located on the outside of the polytetrafluoroethylene anticorrosion and cold-resistant layer 2, and the density is 50Kg / m 3 The thermal conductivity of polyurethane foam can be as low as 0.0235W / (m·k). Compared with thermal insulation materials such as polystyrene particles, it has the advantages of low water absorption, high closed porosity and low thermal conductivity.

[0042] Furthermore, if Figure 1 As shown, the high-density polyethylene protective layer 4 is located at the outermost layer and adopts high-density polyethylene resin. High-density polyethylene resin has excellent mechanical strength, corrosion resistance and sealing performance; at the same time, this layer can play a waterproof and flame retardant role, which can not only protect the integrity of the polyurethane foam insulation layer 3, but also extend the service life of the pipeline and reduce the maintenance cost and replacement cost of internal materials.

[0043] The thermal insulation, sealing and anti-corrosion casing system for ship pipelines of the present invention is provided with a thermal insulation, sealing and anti-corrosion casing formed by a nano antibacterial layer, a polytetrafluoroethylene anti-corrosion and cold-resistant layer, a hard polyurethane foam insulation layer and a high-density polyethylene protective layer on the surface of the ship pipeline; the thicknesses of the nano antibacterial layer 1, the polytetrafluoroethylene anti-corrosion and cold-resistant layer 2, the hard polyurethane foam insulation layer 3 and the high-density polyethylene protective layer 4 are all set according to specific needs, and a co-extrusion molding process is adopted so that the molten streams of the above four materials are co-extruded in a composite head to obtain an integrated composite casing; this integrated structure can ensure that the layers are tightly bonded, thereby improving the overall thermal insulation performance and durability of the pipeline system; the nano antibacterial layer is used to resist oxidation and corrosion inside the pipeline, the polytetrafluoroethylene anti-corrosion and cold-resistant layer is used for insulation and secondary anti-corrosion to resist the invasion of severe cold from the outside, and the low thermal conductivity hard polyurethane foam insulation layer is used to protect the pipeline Secondary insulation is carried out, and the integrity of the rigid polyurethane foam insulation layer is ensured by the high-density polyethylene protective layer, so that the maintenance cost and replacement cost of the rigid polyurethane foam insulation layer and its internal materials are reduced; the thermal insulation, sealing and corrosion-resistant casing of the present invention does not need to install the insulation sleeve on site, which can save labor and time when using the traditional "pipe in pipe" process, and avoid heat loss caused by the bracket; polytetrafluoroethylene has the advantages of acid and alkali resistance and resistance to various organic solvents, and the nano antibacterial layer can resist oxidation and corrosion inside the pipeline, and the double-layer anti-corrosion extends the service life of the pipeline; the double-layer cold-resistant insulation design of the polytetrafluoroethylene anti-corrosion and cold-resistant layer and the rigid polyurethane foam insulation layer ensures that the pipeline does not freeze in the polar low temperature environment, and the layers are tightly bonded, avoiding the reduction of the casing insulation performance caused by uneven polyurethane foaming density and uneven density after molding, and can effectively solve the problems of pipeline freezing, leakage and corrosion in the polar low temperature environment.

[0044] like Figure 2 As shown, the second aspect of the present invention provides a method for preparing a thermal insulation, sealing and anti-corrosion casing for ship pipelines, comprising the following steps:

[0045] S1: Raw material preparation

[0046] Nano antibacterial layer 1 raw materials: prepare nano-level titanium oxide antibacterial materials, and ensure that their purity and particle size meet the requirements in order to form an effective antibacterial layer;

[0047] PTFE anti-corrosion and cold-resistant layer 2 raw materials: Select standard PTFE (Teflon) particles to ensure that it has excellent low temperature resistance and corrosion resistance;

[0048] Rigid polyurethane foam insulation layer 3 raw materials: prepared density is 50Kg / m 3 The polyurethane foam raw material is required to have a thermal conductivity as low as 0.0235W / (m·k) and have characteristics such as low water absorption and high closed cell rate;

[0049] High-density polyethylene protective layer 4 raw materials: select high-density polyethylene resin to ensure that it has excellent mechanical strength, corrosion resistance and sealing performance;

[0050] S2: Extrusion

[0051] (1) Preparation of co-extrusion equipment: Debug the co-extrusion equipment to the best state, including debugging the heating extruder, checking the compound head and preparing the auxiliary equipment to ensure that the molten material flow of each layer can be smoothly co-extruded in the compound head; specifically including:

[0052] Extruder debugging: According to the characteristics of each material, the corresponding extruder is debugged separately. Set the appropriate heating temperature, screw speed and pressure to ensure that the material can be melted evenly and transported smoothly; for example, polytetrafluoroethylene may require a higher temperature, while polyurethane foam requires the addition and temperature of the foaming agent to be controlled;

[0053] Compound die inspection: Check whether the internal structure of the compound die is clean and ensure that there is no residue; adjust the flow channels of each layer of the die so that it can distribute the material flow in the designed order and proportion; check the sealing performance of the die to prevent leakage or layer cross-linking during the extrusion process;

[0054] Preparation of auxiliary equipment: prepare cooling devices (such as water cooling or air cooling systems) to quickly cool and shape the extruded composite sleeve; at the same time, prepare traction devices and cutting devices to control the traction speed and cutting length of the sleeve;

[0055] (2) Melt extrusion: The above four raw materials are added to the corresponding extruders respectively, heated to their respective suitable temperatures, and fully melted; the melted material flows of the nano antibacterial layer, the polytetrafluoroethylene anticorrosive and cold-resistant layer, the rigid polyurethane foam insulation layer and the high-density polyethylene protective layer pass through the extruder in sequence and enter the composite die; specifically, the following steps are performed:

[0056] Raw material addition: Add the raw materials of the nano antibacterial layer 1, the polytetrafluoroethylene anticorrosive and cold-resistant layer 2, the rigid polyurethane foam insulation layer 3 and the high-density polyethylene protective layer 4 into the corresponding extruder hoppers respectively; ensure that the purity and particle size of the raw materials meet the requirements to avoid impurities affecting the extrusion quality;

[0057] Heating and melting: Start the extruder and gradually increase the temperature according to the melting temperature range of the material; for example, the melting temperature of polytetrafluoroethylene is relatively high, which may need to be above 327°C; while the melting temperature of high-density polyethylene is relatively low, generally around 220°C. Keep the temperature stable so that the material can be fully melted and form a uniform melt;

[0058] Material flow conveying: During the melting process, the rotation of the screw conveys the molten material flow to the outlet of the extruder. The speed and pressure of the screw are controlled to ensure the stability and continuity of the material flow, providing a good foundation for subsequent co-extrusion molding;

[0059] (3) Co-extrusion: In the compound die, four molten material flows are co-extruded in the designed order and proportion to form a composite material sleeve after co-extrusion. The design of the compound die should ensure the uniform mixing and tight bonding of each layer of material flow to avoid stratification; specifically including:

[0060] Material flow distribution: After the molten material flows into the composite die, they are distributed according to the designed order and proportion; for example, the nano antibacterial layer may be the innermost layer, the polytetrafluoroethylene anticorrosive and cold-resistant layer may be the second innermost layer, the rigid polyurethane foam insulation layer may be the middle layer, and the high-density polyethylene protective layer may be the outermost layer; the flow channel design inside the composite die should be reasonable to ensure that the material flows of each layer can be evenly mixed;

[0061] Tight bonding: In the composite die, each layer of material flow is tightly bonded by the interface bonding force and the entanglement between molecules under the action of high temperature and pressure. The key to avoiding stratification is to control the temperature and viscosity of each layer of material flow, as well as the flow channel design and pressure distribution of the composite die;

[0062] Extrusion molding: After co-extrusion molding by the composite die, a composite material sleeve with a certain cross-sectional shape and a multi-layer structure is formed; the extruded sleeve needs to maintain a certain temperature for subsequent cooling, shaping and cutting processing;

[0063] S3: Post-processing

[0064] Cooling and shaping: The sleeve after co-extrusion needs to be cooled quickly to shape; usually water cooling (immersing the sleeve in a cooling water tank) or air cooling (blowing cold air on the sleeve surface) is used to keep the composite sleeve after co-extrusion in the required size and shape during the cooling process to obtain the sleeve after cooling and shaping; the cooling speed should be moderate to avoid excessive internal stress of the material or cracks on the surface due to too fast cooling;

[0065] S4: Traction and cutting

[0066] The sleeve after cooling and shaping is pulled by a pulling device, and its pulling speed is controlled to match the extrusion speed; during the pulling process, the sleeve is cut according to a predetermined length using a cutting device to obtain the required finished product segment.

[0067] S5: Quality inspection: Conduct quality inspection on finished casing, including dimensional accuracy, interlayer adhesion, thermal insulation performance and other indicators to ensure that it meets the design requirements; specifically, check whether the casing has defects such as bubbles, cracks, delamination, etc. to ensure that the finished casing meets the design requirements and quality standards.

[0068] S6: Packaging and storage

[0069] Packaging: Pack qualified thermal insulation and sealing sleeves with moisture-proof and dust-proof packaging materials to ensure that they are not damaged during transportation and storage;

[0070] Storage: Store the packaged heat-insulating sealed casing in a dry, ventilated, cool warehouse, away from direct sunlight and high temperature environment to maintain its stable performance;

[0071] Through the above co-extrusion molding process, an insulating sealing sleeve with a multi-layer structure and excellent performance can be efficiently manufactured to ensure that it has excellent thermal insulation, anti-corrosion, antibacterial and self-cleaning properties, and can meet the needs of special application scenarios such as polar low temperature environments.

[0072] Furthermore, the co-extrusion molding in step S2 is a process of simultaneously extruding molten streams of multiple different materials through a composite die to form a multi-layer composite material; the key to ensuring uniform mixing of each layer of material lies in the design of the extruder and the composite die and the control of the process; wherein,

[0073] Extruder and compound die design

[0074] Extruder selection and settings: Select the appropriate extruder type (such as single-screw or twin-screw extruder) according to the characteristics of each material, and accurately set the temperature, pressure and screw speed of each extruder to ensure that the material can be evenly melted and stably conveyed.

[0075] Compound die (mold) design: The design of the compound die is crucial. It needs to ensure that the molten material flow of each layer can be evenly distributed in the designed order and proportion before entering the mold. The flow channel design inside the mold should be reasonable to avoid dead corners and uneven fluid distribution. For example, the die structure with parallel flow sockets and multi-manifold single-slit outlets can make the resin flow in parallel inside the mold, thereby improving the uniformity of interlayer thickness.

[0076] Process Control

[0077] Temperature control: Precisely control the temperature of each extruder and mold to ensure that each layer of material has appropriate viscosity and fluidity when entering the mold so that they can be evenly mixed in the mold. Too high or too low temperature will affect the fluidity and mixing effect of the material.

[0078] Pressure and flow rate control: Keep the pressure and flow rate of each layer consistent to avoid uneven mixing between layers due to pressure or flow rate differences. Pressure and flow rate control can be achieved by adjusting the screw speed and back pressure of the extruder.

[0079] Interface bonding treatment: For some combinations of materials that are difficult to bond, adhesives can be added between layers or compatibilizers can be used to improve the adhesion between the layers and promote uniform mixing.

[0080] The preparation method of the thermal insulation, sealing and anti-corrosion casing for ship pipelines of the present invention adopts a co-extrusion one-piece molding process of "high-density polyethylene protective layer + hard polyurethane foam insulation layer + polytetrafluoroethylene anti-corrosion and cold-resistant layer + nano antibacterial layer" to tightly bond the four layers of materials to form an integral structure of a four-layer insulation casing; compared with traditional insulation pipes, the casing does not require on-site installation of insulation sleeves, saving labor and installation time, and has good wear resistance, corrosion resistance and structural strength; the insulation layer adopts closed-cell foam material, which can effectively block the invasion of external low temperature, and has a low thermal conductivity and good compressive strength; polytetrafluoroethylene has excellent cold resistance, can be used for a long time in a wide temperature range of -180℃ to 260℃, and has outstanding corrosion resistance. The casing has been optimized for polar low-temperature environments in terms of material selection and process design. It has good thermal insulation, anti-corrosion, antibacterial and self-cleaning properties, which can effectively extend the service life of the pipeline and reduce maintenance costs. It can avoid pipe bursting, medium condensation and blockage in low-temperature environments, and can effectively solve problems such as pipeline freezing, leakage and corrosion in polar low-temperature environments.

[0081] The thermal insulation, sealing and anti-corrosion casing system for ship pipelines of the present invention fully considers environmental factors such as temperature gradient, wind direction and speed, and sea ice distribution in the polar environment in the pipeline layout design, and reasonably arranges the direction and position of the pipeline to avoid the pipeline system being directly affected by extreme environmental conditions, such as arranging the pipeline in the internal structure of the ship as much as possible to reduce direct contact with the external low temperature environment. Applying intelligent optimization algorithms, such as EPA-star algorithms, to coordinate the layout optimization of the ship pipeline system can effectively reduce the length of the pipeline and the number of elbows, and improve the compactness and rationality of the pipeline layout. The optimized pipeline layout can not only reduce heat loss, but also improve the maintenance space and operation convenience of the pipeline system; through reasonable material selection, structural design, process flow and optimization measures of pipeline layout, the thermal insulation performance, anti-corrosion performance and overall stability of the ship pipeline system in the polar low temperature environment can be significantly improved, meet the requirements of polar high cold and high latitude environmental conditions, and ensure the safe navigation and effective operation of ships in polar waters.

[0082] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A thermal insulation, sealing and anti-corrosion casing system for ship pipelines, characterized by: It comprises a nano antibacterial layer (1), a polytetrafluoroethylene anticorrosive and cold-resistant layer (2), a hard polyurethane foam insulation layer (3) and a high-density polyethylene protective layer (4) which are arranged in sequence from the inside to the outside in a tubular shape; The nano antibacterial layer (1) is used to resist oxidation and corrosion inside the pipeline, the polytetrafluoroethylene anticorrosion and cold-resistant layer (2) is used to provide heat preservation and secondary anticorrosion to resist the invasion of severe cold from the outside, the low thermal conductivity hard polyurethane foam insulation layer (3) is used to provide secondary heat insulation for the pipeline, and the high-density polyethylene protective layer (4) is used to ensure the integrity of the hard polyurethane foam insulation layer (3), thereby reducing the maintenance cost and replacement cost of the hard polyurethane foam insulation layer (3) and its internal materials; The nano antibacterial layer (1), the polytetrafluoroethylene anticorrosive and cold-resistant layer (2), the hard polyurethane foam insulation layer (3) and the high-density polyethylene protective layer (4) are formed by a co-extrusion molding process, so that the molten material flows of the above four materials are co-extruded in a composite die to obtain a composite material sleeve, which can avoid heat loss caused by the bracket and avoid pipe bursting, medium condensation and blockage in a low-temperature environment.

2. The thermal insulation, sealing and anti-corrosion casing system for ship pipelines according to claim 1 is characterized by: The nano antibacterial layer (1) is a nano-scale titanium oxide antibacterial layer.

3. The thermal insulation, sealing and anti-corrosion casing system for ship pipelines according to claim 1 is characterized by: The polyurethane foam density used in the rigid polyurethane foam insulation layer (3) is 50 Kg / m3 and the thermal conductivity is 0.0235 W / (m·k).

4. The thermal insulation, sealing and anti-corrosion casing system for ship pipelines according to claim 1 is characterized by: The high-density polyethylene protective layer (4) is made of high-density polyethylene resin.

5. A method for preparing a heat-insulating, sealing and anti-corrosion casing for ship pipelines, characterized in that: The method for preparing the heat-insulating, sealing and anti-corrosion casing for ship pipelines according to any one of claims 1 to 4 comprises the following steps: S1: Raw material preparation Prepare the raw materials of the nano antibacterial layer (1), the raw materials of the polytetrafluoroethylene anticorrosive and cold-resistant layer (2), the raw materials of the rigid polyurethane foam insulation layer (3), and the raw materials of the high-density polyethylene protective layer (4); S2: Extrusion The co-extrusion molding equipment is adjusted to the optimal state to ensure that the molten material flows of each layer can be smoothly co-extruded in the composite die; the raw materials of the nano antibacterial layer (1), the polytetrafluoroethylene anti-corrosion and cold-resistant layer, the hard polyurethane foam insulation layer (3), and the high-density polyethylene protective layer (4) prepared in step S1 are respectively added to the corresponding extruders, and heated to their respective suitable temperatures to make them fully melted; the molten material flows of the nano antibacterial layer (1), the polytetrafluoroethylene anti-corrosion and cold-resistant layer (2), the hard polyurethane foam insulation layer (3), and the high-density polyethylene protective layer (4) pass through the extruder in sequence and enter the composite die; in the composite die, the four molten material flows are co-extruded in a designed order and proportion to form a composite material sleeve after co-extrusion molding; S3: Post-processing Using water cooling or air cooling to keep the composite sleeve after co-extrusion in the required size and shape during the cooling process, so as to obtain the sleeve after cooling and finalization; S4: Traction and cutting After cooling and shaping, the sleeve is pulled by a pulling device, and its pulling speed is controlled to match the extrusion speed; during the pulling process, the sleeve is cut according to the predetermined length by a cutting device to obtain the required finished product segment; S5: Quality Inspection Conduct quality inspection on finished casing to ensure that it meets the design requirements and quality standards; S6: Packaging and storage Qualified thermal insulation sealing sleeves should be packaged to ensure that they are not damaged during transportation and storage; the packaged thermal insulation sealing sleeves should be stored in a dry, ventilated and cool warehouse, avoiding direct sunlight and high temperature environment to maintain their stable performance.

6. The method for preparing a heat-insulating, sealing and anti-corrosion casing for ship pipelines according to claim 5, characterized in that: The nano antibacterial layer (1) is a nano-scale titanium oxide antibacterial layer.

7. The method for preparing a heat-insulating, sealing and anti-corrosion casing for ship pipelines according to claim 5, characterized in that: The polyurethane foam density used in the rigid polyurethane foam insulation layer (3) is 50 Kg / m 3 , the thermal conductivity is 0.0235W / (m·k).

8. The method for preparing a heat-insulating, sealing and anti-corrosion casing for ship pipelines according to claim 5, characterized in that: The high-density polyethylene protective layer (4) is made of high-density polyethylene resin.

9. The method for preparing a heat-insulating, sealing and anti-corrosion casing for ship pipelines according to claim 5, characterized in that: The design of the compounding die in step S2 should ensure uniform mixing and tight bonding of the material flows of each layer to avoid stratification.

10. The method for preparing a heat-insulating, sealing and anti-corrosion casing for ship pipelines according to claim 5, characterized in that: In step S5, the quality inspection indicators for the finished casing include dimensional accuracy, interlayer adhesion, and thermal insulation performance.

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