Multi-layer composite spherical tank heat insulation structure and construction method thereof

Abstract

The invention provides a multi-layer composite spherical tank heat insulation structure which comprises a plurality of felt-shaped heat insulation material layers and paste-shaped heat insulation material layers which are alternately arranged on a storage tank body and wrap the storage tank body. The felt-shaped heat insulation material layer and the paste-shaped heat insulation material layer are both aerogel coatings. Comprising strip-shaped heat insulation materials which are wound on the surfaces of felt-shaped heat insulation material layers in a transverse or longitudinal mode and used for fixing the first felt-shaped heat insulation material layer, the third felt-shaped heat insulation material layer, the fifth felt-shaped heat insulation material layer and the like. The netted heat insulation layer is used for fixing the second layer, the fourth layer, the sixth layer... the felt-shaped heat insulation material layer; and the outer protective layer structure plays a role in protecting the whole heat insulation structure. The aerogel felt and the aerogel coating are jointly applied to the storage tank heat insulation field for the first time, and compared with a traditional heat insulation material, the material has the obvious advantages of heat insulation, fire prevention, hydrophobicity and the like; the energy-saving effect of a heat insulation system can be improved, the service life can be prolonged, and the anti-corrosion function, the bonding function, the sealing function, the protection function and the like of a heat insulation structure can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of thermal insulation of storage tanks, and in particular to a multi-layer composite spherical tank thermal insulation structure and a construction method thereof. Background Art

[0002] Spherical tank is a steel pressure vessel equipment, which is a large-capacity, pressure-bearing spherical storage container. It is mainly used to store liquid or gaseous materials in the oil refining industry, petrochemical industry, and liquefied product terminal storage. The operating temperature is generally -50 to 50°C (some working conditions are lower than -100°C), and the operating pressure is generally below 3MPa. Spherical storage tanks are important equipment in industrial fields such as petroleum, chemical industry, metallurgy, terminal storage, and urban gas. The gas or liquid gas stored is mostly flammable, explosive or toxic media. It is a closed pressure container with storage function. Once a problem occurs, the consequences will be catastrophic. Therefore, it is particularly important to carry out corrosion protection, heat preservation, and sealing of spherical storage tanks.

[0003] In practice, a spherical tank is a spherical pressure vessel, and its body is not allowed to add any welded parts at will. When it is insulated, how to fix the insulation material becomes a big problem. The traditional method is to bundle cotton felt materials such as aluminum silicate / glass wool or spray polyurethane materials on site. The cotton felt insulation technology is difficult to construct. The thickness of the insulation layer is mostly above 100mm, the insulation volume is large, and the weight is heavy. There are not many anchor points that can be used for the spherical tank body. The loose bundling leads to large longitudinal and circumferential gaps and serious heat loss. In addition, most of these materials are not waterproof. When encountering rainy weather during operation, they will absorb water and get damp. After getting damp, their own weight increases. In addition, the insulation layer structure itself is not tied tightly, and it gradually slides down along the tank wall under the influence of its own weight during operation. In addition, this process is irreversible. After getting damp, the material becomes powdery, lumpy, and falls off, resulting in the overall insulation performance getting worse year by year. The heat loss is very serious after long-term accumulation. The on-site spraying polyurethane insulation technology is easy to construct and has a low thermal conductivity, but the on-site spraying thickness is difficult to control, resulting in serious local cold loss; and polyurethane is an organic foaming material, the material itself is seriously aged, the flame retardant level is low, it will burn when it encounters fire, and the combustion process produces thick smoke, accompanied by a pungent smell, which is very harmful to the human body; at the same time, most of the media stored in the tank are flammable and explosive, and have high temperature requirements. Once a fire occurs, the consequences are even more unimaginable. It can be seen that the traditional insulation technology, whether it is the material itself, the setting of the insulation structure, or the control during the construction process, will affect its later insulation effect if a certain link is not done well. In order to maintain its insulation effect, the annual maintenance costs paid by the project remain high, but this is also a temporary solution and not a fundamental solution.

[0004] In view of this, how to solve the above technical problems and improve the thermal insulation engineering effect of spherical tanks is a technical challenge that technical personnel in this field need to overcome. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a multi-layer composite insulated spherical tank to solve the problems of poor energy-saving effect and short service life of the existing spherical tank insulation system.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: A multi-layer composite spherical tank insulation structure, in which multiple layers of felt-like insulation material layers and paste-like insulation material layers are alternately arranged on the tank body, and the tank body is covered; The felt-like thermal insulation material layer is layered and wrapped on the outer surface of the tank body by a paste-like thermal insulation material layer and a strip-like thermal insulation material; wherein the felt-like thermal insulation material layer is an aerogel felt, and the paste-like thermal insulation material layer is a water-based aerogel coating.

[0007] Furthermore, the strip-shaped thermal insulation material is wound on the surface of the felt-shaped thermal insulation material layer in a transverse or longitudinal manner to fix the first layer, the third layer, the fifth layer ... of the felt-shaped thermal insulation material layer.

[0008] Furthermore, a mesh insulation layer is provided outside the second, fourth, sixth ... felt insulation material layers. The mesh insulation layer is a metal mesh structure made of steel wire / iron wire. The metal mesh structure has higher strength and greater fixing strength than strip insulation material, and can firmly bind multiple layers of felt insulation material layers to the surface of the spherical tank body.

[0009] Furthermore, the aerogel felt of the felt-like thermal insulation material layer is cut into fan-shaped or quadrilateral structures and then spliced ​​together so as to fit tightly with the spherical tank; the splicing seams are sealed with a gel-like adhesive or butyl tape.

[0010] Furthermore, a paste-like insulation structure outer protective layer structure is sprayed on the outermost layer to protect the overall insulation structure.

[0011] Wherein, the felt-like thermal insulation material layer is made of low-temperature special aerogel felt, glass elastic felt, rock wool felt or rubber-plastic felt.

[0012] Among them, the paste-like insulation material layer adopts environmentally friendly water-based aerogel coating, including but not limited to: polyurethane system aerogel coating, polytetrafluoroethylene PTFE system aerogel coating, vinyl acetate system aerogel coating or styrene acrylic system aerogel coating. The paste-like insulation material plays the role of bonding and curing the surface powder of the aerogel felt and filling the gaps of the aerogel felt.

[0013] The present invention also provides a construction method of a multi-layer composite spherical tank insulation structure, comprising the following steps: (1) According to the size of the spherical tank, cut the aerogel felt into fan-shaped or quadrilateral shapes for later use; (2) Spray aerogel coating on the surface of the spherical tank with a thickness of 1-5 mm; (3) laying the cut aerogel felt on the surface of the spherical tank from top to bottom, and using strip-shaped insulation material (5) to wrap around the surface of the felt-shaped insulation material layer (2) in a horizontal or vertical manner to fix the first layer, the third layer, the fifth layer, etc. of the felt-shaped insulation material layer (2), and sealing the joints with butyl tape; (4) Repeat steps (2) and (3) until the cold insulation structure reaches the required thickness; (5) Spray the outermost layer of paint with a thickness of 1-5 mm.

[0014] Furthermore, a mesh insulation layer is provided outside the second, fourth, sixth ... felt insulation material layers, and the mesh insulation layer is a metal mesh structure made of steel wire / iron wire.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The multi-layer composite insulation structure of the present invention combines aerogel felt and aerogel coating for the first time in the field of tank insulation. The material itself has obvious advantages over traditional insulation materials in terms of insulation, fire resistance, and water repellency. It can not only improve the energy-saving effect of the insulation system and extend its service life, but also improve the anti-corrosion, bonding, sealing, and protection functions of the insulation structure. Aerogel coating makes up for the "thermal bridge" and powder loss problems at the joints of aerogel felt; aerogel felt makes up for the curing time and service life problems of aerogel coating when applied thickly. The combined use of the two plays a role of 1+1>2.

[0016] 2. The present invention adopts a new multi-layer composite insulation structure with alternating aerogel felt and coating, which can achieve self-adhesion and self-sealing effects while providing insulation. The functions of the two materials complement each other, and the economic and energy-saving benefits are remarkable.

[0017] 3. The invention has a simple construction method, low construction cost and short construction period.

[0018] 4. The multi-layer composite insulation technology of the present invention can be applied not only to spherical tanks, but also to some large storage tanks / equipment and other fields. It can be used not only in low temperature fields, but also in high temperature fields. Its temperature resistance range is -196℃~800℃. According to different working conditions, the corresponding insulation thickness is designed, and the corresponding multi-layer composite insulation layer structure is further designed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : Schematic diagram of the multi-layer composite insulation structure of the present invention; Figure 2 : Schematic diagram of the sliced ​​structure of the felt-like thermal insulation material of the present invention; Figure 3 : Schematic diagram of the fixing structure of the strip insulation material according to an embodiment of the present invention; Figure 4 : Schematic diagram of the fixing structure of the mesh insulation layer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the present invention will be clearly and completely described below in conjunction with the drawings and specific examples. Obviously, the embodiments are only part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. 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.

[0023] In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third" and the like are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of 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 specific circumstances.

[0024] See also Figure 1 The present invention relates to a multi-layer composite spherical tank insulation structure, in which multiple layers of felt-like insulation material layers 2 and paste-like insulation material layers 3 are alternately arranged on a spherical tank body 1, and the spherical tank body 1 is covered.

[0025] The spherical tank body 1 is a spherical container, which is fixed to the ground by bottom legs. The volume of the spherical tank varies from 300 to 6000m³. There are three types of petal divisions: orange petal type, football petal type or mixed type. The material of the spherical tank body is generally steel or aluminum.

[0026] The felt-like thermal insulation material layer 2 adopts the existing thermal insulation aerogel felt, which is layered and wrapped on the outer surface of the tank body 1 through multiple layers of paste-like thermal insulation material layers 3 and strip-like thermal insulation material 5. In order to better fit the aerogel felt with the spherical tank body 1, it is cut into a fan-shaped or quadrilateral structure such as Figure 2 The multi-layer felt-like heat-insulating material layer 2 forms longitudinal and circumferential joint seams 4 when being joined on the surface of the spherical tank body 1, and the joint seams 4 are sealed with a glue-like adhesive or a butyl tape.

[0027] The multi-layer paste insulation material layer 3 adopts the existing environmentally friendly water-based aerogel coating, including but not limited to: polyurethane system aerogel coating, polytetrafluoroethylene system aerogel coating, vinyl acetate system aerogel coating or styrene acrylic system aerogel coating. The multi-layer paste insulation material plays the role of bonding, curing the surface powder of the aerogel felt and filling the gaps of the aerogel felt. Spraying it on the surface of the spherical tank body 1 can provide secondary corrosion protection for the tank body itself. At the same time, it can also well bond the first layer of felt insulation layer 2, and then spray a layer of paste insulation material layer 3. Repeat the construction of the felt insulation layer and the paste insulation material until the designed insulation thickness is reached. Spray a layer of paste insulation structure outer protective layer structure 7 on the outside to protect the overall insulation structure.

[0028] See also Figure 3 The strip-shaped thermal insulation material 5 adopts glass fiber tape, which is used to fix the first layer, the third layer, the fifth layer...the felt-shaped thermal insulation material layer 2, and is wound on the surface of the felt-shaped thermal insulation material layer 2. Multiple strip-shaped thermal insulation materials 5 need to be wound horizontally or vertically.

[0029] See also Figure 4 The mesh insulation layer 6 is a metal mesh structure made of steel wire / iron wire, which is used to fix the second, fourth, sixth...felt insulation material layer 2. The metal mesh structure is stronger than the strip insulation material 5 and has a large fixing strength, and can firmly bind the multiple layers of felt insulation material 2 to the surface of the spherical tank body 1. The insulation structure outer sheath structure 7 is a water-based aerogel coating with weather resistance, heat reflection, heat radiation, and aesthetic functions. It is usually constructed by spraying, and the thickness is mostly 1 to 3 mm. On the one hand, the aerogel coating fills the concave and convex parts produced by the combination of strip and mesh materials and aerogel felt, making the surface smooth and beautiful; on the other hand, it provides excellent heat reflection and heat radiation to prevent the problem of heat accumulation caused by the external environment, especially long-term sunlight exposure.

[0030] The construction method of the multi-layer composite insulation structure of the present invention comprises: first fixing the inner layer of aerogel felt with aerogel coating; then fixing the first, third, fifth...layers of aerogel felt with aluminum foil tape; and reinforcing and fixing the second, fourth, sixth...layers of aerogel felt with steel wire mesh in the middle.

[0031] The aerogel coating used in the present invention is divided into aerogel anticorrosive primer, aerogel heat insulation middle coating, and aerogel weather-resistant reflective heat insulation surface layer. Different systems and models of aerogel coatings are selected for different substrates, different working conditions and locations. The appropriate aerogel coating system is equipped according to the working conditions of the project to achieve better results.

[0032] Example 1 (cold-keeping spherical tank) See also Figure 1 The ethylene storage tank of a chemical plant has a single capacity of 2000m³, a design temperature of -40℃, and a design pressure of 2.2 MPa. It is required to carry out cold insulation treatment on the outer surface of the storage tank, and it is required that no condensation occurs on the outer surface of the cold insulation layer after cold insulation.

[0033] 1. Design the cold-keeping structure required for the spherical tank According to the anti-condensation requirements specified in GB50264, refer to the local meteorological parameters: Calculated outdoor dry bulb temperature for air conditioning in summer: 33.5℃; Relative humidity: 41% Wind speed: 2m / s Dew point temperature: 18.1℃ Based on this, the required cold insulation structure of the spherical tank is calculated, that is, the main cold insulation material: 45mm aerogel felt + 3mm aerogel coating. Among them, the cold insulation layer structure is designed as follows: The cold preservation structure from inside to outside: spherical tank body—0.2mm aerogel coating—first layer of aerogel felt 5mm—0.2mm aerogel coating—second layer of aerogel felt 10mm—0.2mm aerogel coating—third layer of aerogel felt 10mm—0.2mm aerogel coating—fourth layer of aerogel felt 10mm—0.2mm aerogel coating—fifth layer of aerogel felt 10mm—2mm aerogel coating (as outer protective layer).

[0034] 2. The construction method of the cold insulation structure includes the following steps: (1) Cutting of cold insulation materials: According to the size of the spherical tank, the aerogel felt is cut into fan-shaped or quadrilateral shapes using a paper cutter on site. Figure 2 (a) or (b); (2) Spraying the first layer of aerogel coating: spray the first layer of aerogel coating on the surface of the spherical tank with a thickness of 0.2 mm; (3) Laying the first layer of aerogel special cold insulation felt: Lay the cut aerogel special cold insulation felt on the surface of the spherical tank from top to bottom, wrap it with strip insulation material 5 glass fiber tape / other strip tape to fix it, and seal the gap with butyl tape; (4) Spraying the second layer of aerogel coating: spray the second layer of aerogel coating on the surface of the first layer of aerogel special cold insulation felt, with a thickness of 0.2 mm; (5) Laying the second layer of aerogel special cold insulation felt: Lay the cut aerogel special cold insulation felt on the surface of the spherical tank from top to bottom, wrap it with glass fiber tape to fix it, and seal the gaps with butyl tape; and fix it with a mesh insulation material layer 6, i.e., stainless steel wire mesh / fiber mesh cloth, etc. The stainless steel wire mesh / fiber mesh cloth serves as an integral fixing structure, which can firmly fix the internal insulation structure on the surface of the spherical tank.

[0035] (6) Repeat steps (2) to (5) until the cold insulation structure reaches the required thickness; (7) Spray the outermost layer of paint with a thickness of 2 mm.

[0036] In the present invention, both aerogel felt and aerogel coating can be existing mature products. For example, the aerogel felt adopts the new material HL Cryshield model cold-insulation special aerogel felt - 1.5 meters wide and 10 mm thick, which is one of the cold-insulation materials with the lowest thermal conductivity known so far and can be used at -196°C to 800°C; the aerogel coating adopts the industrial cold-insulation anti-condensation aerogel coating HL PYSHIELD TM-GY-B-S40, which plays the functions of corrosion prevention, bonding, sealing and protection in the entire cold-insulation structure. After the structure is successfully implemented, the surface temperature is only 1.2°C lower than the ambient temperature and about 3°C ​​higher than the dew point temperature, which fully meets the anti-condensation requirements of the design requirements.

[0037] The multi-layer composite spherical tank insulation structure and the construction method thereof of the present invention also have the following significant effects: First, spraying aerogel coating on the surface of the spherical tank can provide secondary corrosion protection for the tank body, thereby improving the corrosion resistance level. Traditional insulation cotton will aggravate the corrosion of the tank body after absorbing water.

[0038] Secondly, aerogel coating and aerogel felt can firmly bond to the surface of the spherical tank, which effectively solves the problem that there is no anchor point on the surface of the spherical tank and the cold insulation structure cannot be fixed. However, the traditional thermal insulation cotton is not firmly fixed, and the material falls during operation, which is also the reason why its energy-saving effect is declining year by year.

[0039] Third, spraying aerogel felt coating on the outer surface of each layer of aerogel felt can also play a secondary sealing function on the longitudinal and circumferential seams of the cold-insulating structure, reducing the hidden dangers of cold leakage / heat dissipation at the gaps. In addition, there are also reinforcements of strip insulation materials and mesh insulation material layers, which can firmly bind multiple layers of felt insulation materials to the surface of the spherical tank body.

[0040] Finally: Spraying 2mm reflective heat-insulating aerogel coating on the outermost layer not only increases the cold-insulating effect, but also improves the fireproof and waterproof performance of the entire cold-insulating structure, making the entire cold-insulating structure more economical and energy-saving. Compared with the traditional process of using metal aluminum plates as the outer sheath, it not only increases the weight, but also has low corrosion resistance; in addition, the installation of the metal plate itself will leave many gaps, which are channels for rainwater to enter the insulation structure later.

[0041] The cold-keeping structure of the present invention has "five super" properties: (1) Superb cold-keeping performance, thermal conductivity ≤ 0.018w / mk. This solves the problem of high thermal conductivity and thick insulation thickness of traditional insulation materials.

[0042] (2) Super high fire resistance, with a fire resistance rating of Class A. This solves the potential safety hazard of traditional insulation materials with insufficient fire resistance.

[0043] (3) Super strong water repellency, with a water repellency rate of ≥98%. This solves the problem that the thermal insulation performance of traditional thermal insulation materials decreases year by year due to water absorption.

[0044] (4) Superb mechanical properties, good flexibility, easy cutting and simple construction. It solves the problems of traditional insulation materials such as large construction volume, heavy workload and long construction period.

[0045] (5) Super strong sealing performance, factory-coated, moisture permeability ≤8.7×10-10g / (㎡sPa). This solves the problem of traditional thermal insulation structure that water vapor intrusion causes frost and ice inside the cold insulation structure, which affects the cold insulation effect.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A multi-layer composite spherical tank insulation structure, characterized in that: Multiple layers of felt-like heat-insulating material layers (2) and paste-like heat-insulating material layers (3) are alternately arranged on the storage tank body (1), and the storage tank body (1) is covered; The felt-like thermal insulation material layer (2) is wrapped in layers on the outer surface of the storage tank body (1) by means of a paste-like thermal insulation material layer (3) and a strip-like thermal insulation material (5); wherein the felt-like thermal insulation material layer (2) is an aerogel felt, and the paste-like thermal insulation material layer (3) is a water-based aerogel coating.

2. The multi-layer composite spherical tank insulation structure according to claim 1 is characterized in that: The strip-shaped thermal insulation material (5) is wound horizontally or vertically on the surface of the felt-shaped thermal insulation material layer (2) to fix the first layer, the third layer, the fifth layer, ... the felt-shaped thermal insulation material layer (2).

3. The multi-layer composite spherical tank insulation structure according to claim 1 is characterized in that: A mesh insulation layer (6) is provided outside the second, fourth, sixth, ... felt insulation material layers (2). The mesh insulation layer (6) is a metal mesh structure made of steel wire / iron wire. The metal mesh structure has higher strength and greater fixing strength than the strip insulation material (5), and can firmly bind the multiple layers of felt insulation material layers (2) to the surface of the spherical tank body (1).

4. The multi-layer composite spherical tank insulation structure according to claim 1 is characterized in that: The felt-like thermal insulation material layer (2) is formed by cutting the aerogel felt into a fan-shaped or quadrilateral structure and then splicing it so that it fits tightly with the spherical tank; the splicing seam (4) is sealed with a gel adhesive or butyl tape.

5. The multi-layer composite spherical tank insulation structure according to claim 1 is characterized in that: The outermost layer is also sprayed with a paste-like insulation structure outer protective layer structure (7) to protect the overall insulation structure.

6. The multi-layer composite spherical tank insulation structure according to any one of claims 1 to 4, characterized in that: The felt-like thermal insulation material layer (2) is made of low-temperature special aerogel felt, glass elastic felt, rock wool felt or rubber-plastic felt.

7. The multi-layer composite spherical tank insulation structure according to claim 1 is characterized in that: The paste-like thermal insulation material (3) adopts an environmentally friendly water-based aerogel coating, such as a polyurethane system aerogel coating, a polytetrafluoroethylene (PTFE) system aerogel coating, a vinyl acetate system aerogel coating or a styrene acrylic system aerogel coating.

8. A construction method for a multi-layer composite spherical tank insulation structure, characterized in that: The steps include: (1) According to the size of the spherical tank, cut the aerogel felt into fan-shaped or quadrilateral shapes for later use; (2) Spray aerogel coating on the surface of the spherical tank with a thickness of 1-5 mm; (3) laying the cut aerogel felt on the surface of the spherical tank from top to bottom, and using strip-shaped insulation material (5) to wrap around the surface of the felt-shaped insulation material layer (2) in a horizontal or vertical manner to fix the first layer, the third layer, the fifth layer, etc. of the felt-shaped insulation material layer (2), and sealing the joints with butyl tape; (4) Repeat steps (2) and (3) until the cold insulation structure reaches the required thickness; (5) Spray the outermost layer of paint with a thickness of 1-5 mm.

9. The construction method of the multi-layer composite spherical tank insulation structure according to claim 8 is characterized in that: A mesh insulation layer (6) is provided outside the second, fourth, sixth, ... felt-like insulation material layers (2), and the mesh insulation layer (6) is a metal mesh structure made of steel wire / iron wire.

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