Liquefied hydrocarbon spherical tank composite protection structure and design method thereof

Abstract

The present application relates to the technical fields of spherical tank protection, and particularly relates to a liquefied hydrocarbon spherical tank composite protection structure and a design method thereof. The liquefied hydrocarbon spherical tank composite protection structure comprises a tank body protection cover for protecting the tank body. The tank body protection cover comprises an impact resistance layer in contact with the tank body and an energy absorption layer arranged on the impact resistance layer. The impact resistance layer comprises a grid and ceramic sheets arranged in a plurality of unit grids of the grid. By using the protection structure, the tank body is protected by the tank body protection cover comprising the impact resistance layer and the energy absorption layer, and the impact resistance layer comprises the grid and the ceramic sheets arranged in the plurality of unit grids of the grid. In actual application, the safety of the spherical tank can be effectively ensured, and large splashes and / or explosion shock waves impacting the spherical tank to cause damage to the spherical tank can be prevented. The present application has the advantages of simple operation, simple structure, high safety and cost saving.

Description

Technical Field

[0001] This invention relates to the field of spherical tank protection technology, specifically to a composite protective structure for liquefied hydrocarbon spherical tanks and its design method. Background Technology

[0002] Liquefied hydrocarbon spherical tanks, as a thin-shell structure, have many advantages such as large capacity, low cost, and good stability, and are therefore widely used in petrochemical enterprises and chemical industrial parks. However, under the impact of flammable vapor cloud explosions or splashes, thin-walled steel storage tanks are prone to large plastic deformation or penetration damage, which can lead to leakage of internal flammable materials, resulting in secondary explosions or even a chain reaction of domino effects.

[0003] Currently, existing domestic and international standards and specifications have not proposed effective measures for explosion-proof and impact-resistant protection of spherical tanks. Therefore, the most common methods for protecting spherical tanks are masonry walls or concrete protective plates to create a safe environment and ensure the safety of the tank. However, these methods are only applicable to some small spherical tanks and are difficult to apply to large-sized and high-pressure spherical tanks. They also have the disadvantages of being complex to implement and costly. In some application sites, these methods cannot be used to protect spherical tanks.

[0004] Specifically, for example, patent application CN212178515U discloses a storage tank device. On the one hand, it uses a heat-insulating medium filled in an airtight protective cavity formed by the tank body, concrete retaining wall, protective top cover, and ground to insulate the tank body from the outside world, preventing external heat from being directly transferred to the tank body, thereby effectively preventing the storage tank explosion and fire hazard caused by the expansion of liquid materials due to heating and vaporization. On the other hand, the tank body is placed in an airtight protective cavity formed by the concrete retaining wall, protective top cover, and ground, which is sealed and isolated from the outside world, avoiding direct exposure of the tank body to the outside world. The concrete retaining wall and protective top cover prevent the tank body from being damaged by nearby heat sources, explosion shock waves, splashing objects, or other sudden damage, ensuring the safety of liquefied hydrocarbon materials storage and thus reducing the safety production hazards in the storage and transportation tank area of ​​petrochemical enterprises.

[0005] Furthermore, most current protective structures for spherical tanks only consider the scenario of fragment penetration, without considering the scenario of large splashes generated by the explosion source. However, the petrochemical accidents that have occurred so far show that the explosion process can generate splashes weighing hundreds of kilograms and projected tens of meters away.

[0006] Therefore, there is an urgent need for a composite protective structure and design method for liquefied hydrocarbon spherical tanks to comprehensively improve the explosion-proof and impact-resistant performance of spherical tanks and meet the application needs of different scenarios. Summary of the Invention

[0007] The purpose of this invention is to address the problems in the prior art regarding the protection of spherical tanks, especially large liquefied hydrocarbon spherical tanks, which lack effective and easily implemented protective structures and cannot effectively protect against large splashes. This invention provides a composite protective structure for liquefied hydrocarbon spherical tanks and its design method.

[0008] To achieve the above objectives, a first aspect of the present invention provides a composite protective structure for a liquefied hydrocarbon spherical tank, the protective structure comprising:

[0009] A tank protective cover is used to protect the tank. The tank protective cover includes an impact-resistant layer in contact with the tank and an energy-absorbing layer disposed on the impact-resistant layer. The impact-resistant layer includes a grid and ceramic plates disposed in a plurality of unit grids of the grid.

[0010] Preferably, the surface of the ceramic sheet disposed within the unit grid is covered with fibers.

[0011] Preferably, the types of fibers include basalt fiber, glass fiber, and carbon fiber; the types of ceramic sheets include alumina ceramic, silicon carbide ceramic, and titanium diboride ceramic.

[0012] Preferably, the thickness of the vertical bars h1 of the grille is 0.5-1.5cm, and the thickness of the horizontal bars c1 is 0.2-0.8cm.

[0013] Preferably, the unit grid is square, and the side length r1 of the square unit grid is 4-5 cm.

[0014] Preferably, one or both sides of the grid on which the ceramic sheet is disposed are coated with a polyurea layer.

[0015] Preferably, the energy-absorbing layer is made of an energy-absorbing material, which includes porous foam material, honeycomb structure and superelastic material.

[0016] Preferably, the porous foam material includes polyurethane foam and aluminum foam.

[0017] Preferably, the energy-absorbing layer comprises multiple layers arranged in a gradient, with the density and / or plateau stress of each layer decreasing sequentially from the inside to the outside.

[0018] Preferably, the surface of the energy-absorbing layer is coated with a fireproof and heat-insulating layer.

[0019] A second aspect of the present invention provides a design method for a composite protective structure for a liquefied hydrocarbon spherical tank, applicable to the aforementioned composite protective structure for the liquefied hydrocarbon spherical tank. The design method includes:

[0020] Based on the installation location of the liquefied hydrocarbon spherical tank, a quantitative assessment of the risks it faces is conducted using the TNO multi-energy method to obtain quantitative assessment results. The quantitative assessment results include the peak incident overpressure and duration of the explosion shock wave experienced by the liquefied hydrocarbon spherical tank, the mass and velocity of the splashed material, and the fire hazard level.

[0021] Based on the quantitative assessment results, a composite protective structure for liquefied hydrocarbon spherical tanks was designed.

[0022] Preferably, the quantitative assessment of the risks faced based on the TNO multi-energy method specifically includes:

[0023] Identify potential explosion sources and explosion receivers for each structure or tank area, determine the volume of obstacles within the explosion source and the effective volume of the obstructed area of ​​the explosion source, model each potential explosion source, and assess the impact of explosion shock wave overpressure and splashes on liquefied hydrocarbon spherical tanks.

[0024] Preferably, the step of designing the composite protective structure for the liquefied hydrocarbon spherical tank based on the quantitative assessment results specifically includes:

[0025] The thickness of the impact-resistant layer was determined using numerical simulation based on the mass and velocity of the splashing material.

[0026] Based on the peak incident overpressure and duration of the blast shock wave, the peak incident overpressure and duration of the shock wave are converted into peak reflected pressure and equivalent positive action time using the blast shock wave calculation formula. Based on the peak reflected pressure and equivalent positive action time, the thickness and material parameters of the energy-absorbing layer are determined using the energy-absorbing material decomposition algorithm. Finally, the material to be used is determined based on the determined thickness and material parameters of the energy-absorbing layer.

[0027] The thickness of the fireproof insulation layer is determined using numerical simulation based on the fire hazard level.

[0028] Preferably, the formula for calculating the explosion shock wave includes:

[0029] P r =C r *P so

[0030] C r =2 + 0.0073P so

[0031] Among them, P so For the peak incident overpressure of the explosion shock wave, P r For peak reflected pressure, C r This is the reflection coefficient.

[0032] Preferably, the material parameters include density, plateau stress, and strain rate.

[0033] According to the above technical solution, based on the composite protective structure of the liquefied hydrocarbon spherical tank, the tank body is protected by the tank body protective cover including an impact-resistant layer and an energy-absorbing layer. The impact-resistant layer includes a grid and ceramic pieces arranged in several unit grids of the grid. In practical applications, it can effectively ensure the safety of the spherical tank and prevent large splashes and / or explosive shock waves from impacting the spherical tank and causing damage to the spherical tank. It has the advantages of simple operation, simple structure, high safety and cost saving.

[0034] Meanwhile, by coating the surface of the ceramic sheet disposed within the unit grid with fibers, the protective performance of the impact-resistant layer can be further improved based on the combination of the grid and the ceramic sheet.

[0035] The use of fibers, including basalt fiber, glass fiber, and carbon fiber, and ceramic sheets, including alumina ceramic, silicon carbide ceramic, and titanium diboride ceramic, can further and effectively improve the protective performance of the impact-resistant layer.

[0036] The vertical bars h1 of the grid have a thickness of 0.5-1.5cm, and the horizontal bars c1 have a thickness of 0.2-0.8cm. Furthermore, the unit grid is square, and the side length r1 of the square unit grid is 4-5cm. In practical applications, this can further improve the protective performance of the impact-resistant layer.

[0037] By coating one or both sides of the grid on which the ceramic sheet is disposed with a polyurea layer, the protective performance of the impact-resistant layer can be further improved.

[0038] The energy-absorbing layer is made of energy-absorbing materials, including porous foam materials, honeycomb structures, and superelastic materials. The porous foam materials include polyurethane foam and aluminum foam. In practical applications, it can effectively absorb blast shock waves. When used in conjunction with the impact-resistant layer, it can also effectively improve the impact-resistant layer's protective performance against flying debris.

[0039] By configuring the energy-absorbing layer to include multiple layers arranged in a gradient, with the density and / or plateau stress of each layer decreasing sequentially from the inside to the outside, the protective performance of the energy-absorbing layer can be further improved effectively. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the cross-sectional structure of the composite protective structure for a liquefied hydrocarbon spherical tank;

[0041] Figure 2 This is a schematic diagram of the grid structure of the composite protective structure for liquefied hydrocarbon spherical tanks;

[0042] Figure 3 This is a schematic diagram of the ceramic sheet structure of the composite protective structure for a liquefied hydrocarbon spherical tank;

[0043] Figure 4 This is a schematic diagram of the structure of a ceramic sheet coated with fibers;

[0044] Figure 5 This is an illustration of a grid filled with fiber-coated ceramic sheets.

[0045] Explanation of reference numerals in the attached figures

[0046] 1. Grille; 2. Unit grid; 3. Ceramic sheet; 4. Fiber. Detailed Implementation

[0047] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0048] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean a non-exclusive inclusion, the possibility of the presence or addition of one or more other features, units, components, and / or combinations thereof.

[0049] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0050] The first aspect of this invention provides a composite protective structure for liquefied hydrocarbon spherical tanks, such as... Figure 1-5 As shown, the composite protective structure of the liquefied hydrocarbon spherical tank includes:

[0051] A tank protective cover is used to protect the tank. The tank protective cover includes an impact-resistant layer in contact with the tank and an energy-absorbing layer disposed on the impact-resistant layer. The impact-resistant layer includes a grid 1 and ceramic sheets 3 disposed in a plurality of unit grids 2 of the grid 1.

[0052] According to the above technical solution, based on the composite protective structure of the liquefied hydrocarbon spherical tank, the tank body is protected by the tank body protective cover including an impact-resistant layer and an energy-absorbing layer. The impact-resistant layer includes a grid and ceramic pieces arranged in several unit grids of the grid. In practical applications, it can effectively ensure the safety of the spherical tank and prevent large splashes and / or explosive shock waves from impacting the spherical tank and causing damage to the spherical tank. It has the advantages of simple operation, simple structure, high safety and cost saving.

[0053] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, preferably, the surface of the ceramic sheet 3 disposed within the unit grid 2 is covered with fibers 4.

[0054] In a further preferred embodiment, the fiber 4 includes basalt fiber, glass fiber, and carbon fiber; the ceramic sheet 3 includes alumina ceramic, silicon carbide ceramic, and titanium diboride ceramic.

[0055] In this invention, such as Figure 2-5 As shown, by further coating the surface of the ceramic sheet 3 with fibers 4 and further defining the types of fibers and ceramic sheets, the protective performance of the impact-resistant layer can be effectively improved in practical applications.

[0056] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, preferably, the thickness of the vertical bar h1 of the grille 1 is 0.5-1.5cm, more preferably 0.8-1.2cm, and most preferably 1cm, and the thickness of the horizontal bar c1 is 0.2-0.8cm, more preferably 0.4-0.6cm, and most preferably 0.5cm.

[0057] In a further preferred embodiment, the unit grid 2 is square, and the side length r1 of the square unit grid 2 is 4-5cm, preferably 4.2-4.8cm, and most preferably 4.5cm.

[0058] In this invention, such as Figure 2 As shown, by limiting the thickness of the vertical bars h1 and the horizontal bars c1 of the grid 1, the protective performance of the impact-resistant layer can be further improved in practical applications. Furthermore, by limiting the shape of the unit grid 2 to a square, with a side length r1 of 4-5 cm, the protective performance of the impact-resistant layer can be further improved in practical applications.

[0059] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, preferably, one or both sides of the grid 1 on which the ceramic sheet 3 is disposed are coated with a polyurea layer. Preferably, the polyurea layer is coated on the side of the grid 1 on which the ceramic sheet 3 is disposed, away from the tank body. More preferably, the polyurea layer is coated on both sides of the grid 1 on which the ceramic sheet 3 is disposed.

[0060] In this invention, the ceramic sheet 3 is constrained by coating it with a polyurea layer, which can further improve the protective performance of the impact-resistant layer.

[0061] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, preferably, the energy-absorbing layer is made of an energy-absorbing material, which includes porous foam materials, honeycomb structures, and hyperelastic materials. More preferably, the porous foam material includes polyurethane foam and aluminum foam.

[0062] In this invention, preferably, the energy-absorbing layer is made of the porous foam material, and most preferably, the energy-absorbing layer is made of polyurethane foam, thereby effectively improving the protective performance of the energy-absorbing layer.

[0063] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, in a preferred embodiment, the energy-absorbing layer comprises multiple layers arranged in a gradient, with the density and / or platform stress of each layer decreasing sequentially from the inside to the outside.

[0064] In this invention, by designing the energy-absorbing layer as a multi-layered structure with a gradient arrangement, and the density and / or plateau stress of each layer decreasing sequentially from the inside to the outside, the protective performance of the energy-absorbing layer can be effectively improved in practical applications through layer-by-layer energy absorption. In the most preferred embodiment, the energy-absorbing layer comprises three layers arranged in a gradient, with the density and plateau stress of each layer decreasing sequentially from the inside to the outside.

[0065] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, preferably, the surface of the energy-absorbing layer is coated with a fireproof and heat-insulating layer.

[0066] In this invention, by assessing the potential fire hazard level of the liquefied hydrocarbon spherical tank and selecting a suitable fireproof and heat-insulating layer to coat the energy-absorbing layer, the impact of high fire temperatures on the materials inside the tank can be effectively avoided.

[0067] A second aspect of the present invention provides a design method for a composite protective structure for a liquefied hydrocarbon spherical tank, applicable to the aforementioned composite protective structure for the liquefied hydrocarbon spherical tank. The design method includes:

[0068] Based on the installation location of the liquefied hydrocarbon spherical tank, a quantitative assessment of the risks it faces is conducted using methods such as the TNO multi-energy method to obtain quantitative assessment results. The quantitative assessment results include the peak incident overpressure and duration of the explosion shock wave experienced by the liquefied hydrocarbon spherical tank, the mass and velocity of the splashed material, and the fire hazard level.

[0069] Based on the quantitative assessment results, a composite protective structure for liquefied hydrocarbon spherical tanks was designed.

[0070] According to the above technical solution, by quantitatively assessing the risks faced by the liquefied hydrocarbon spherical tank based on the installation location and methods such as the TNO multi-energy method, a quantitative assessment result is obtained. Based on the quantitative assessment result, a composite protective structure for the liquefied hydrocarbon spherical tank is designed. This can further improve the efficiency of the design of the composite protective structure for the liquefied hydrocarbon spherical tank and avoid the situation where the protective performance of the provided composite protective structure for the liquefied hydrocarbon spherical tank is at least one energy level higher than the required protective level without accurate basis, thus avoiding increased costs.

[0071] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, in a preferred embodiment, the quantitative assessment of the risks faced based on methods such as the TNO multi-energy method specifically includes:

[0072] Identify potential explosion sources and explosion receivers for each structure or tank area, determine the volume of obstacles within the explosion source and the effective volume of the obstructed area of ​​the explosion source, model each potential explosion source, and assess the impact of explosion shock wave overpressure and splashes on liquefied hydrocarbon spherical tanks.

[0073] In this invention, the accuracy of the quantitative assessment results can be further improved by further quantifying the risks that liquefied hydrocarbon spherical tanks may face.

[0074] In the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention, preferably, the step of designing the composite protective structure for liquefied hydrocarbon spherical tanks based on the quantitative evaluation results specifically includes:

[0075] The thickness of the impact-resistant layer was determined using numerical simulation based on the mass and velocity of the splashing material.

[0076] Based on the peak incident overpressure and duration of the blast shock wave, the peak incident overpressure and duration of the shock wave are converted into peak reflected pressure and equivalent positive action time using the blast shock wave calculation formula. Based on the peak reflected pressure and equivalent positive action time, the thickness and material parameters of the energy-absorbing layer are determined using the energy-absorbing material decomposition algorithm. Finally, the material to be used is determined based on the determined thickness and material parameters of the energy-absorbing layer.

[0077] The thickness of the fireproof insulation layer is determined using numerical simulation based on the fire hazard level.

[0078] In this invention, by further refining the specific method for designing a composite protective structure for liquefied hydrocarbon spherical tanks based on the quantitative evaluation results, a composite protective structure for liquefied hydrocarbon spherical tanks that meets the needs of practical applications can be designed quickly and accurately in actual applications, and costs can be effectively reduced.

[0079] In a further preferred embodiment, the formula for calculating the explosion shock wave includes:

[0080] P r =C r *P so

[0081] C r =2 + 0.0073P so

[0082] Among them, P so For the peak incident overpressure of the explosion shock wave, P r For peak reflected pressure, C r This is the reflection coefficient.

[0083] In another further preferred embodiment, the material parameters include density, plateau stress, and strain rate. More preferably, the density is 40-120 kg / m³. 3 The preferred value is 50-100 kg / m³. 3 The platform stress is 20-50 kPa; the strain rate is greater than 0.3; thereby further improving design efficiency and reducing costs.

[0084] In this invention, the impact-resistant layer, energy-absorbing layer, and fireproof insulation layer in the tank protective cover can be further configured according to the application needs of the actual application scenario. Specifically, the tank protective cover includes one or more of the impact-resistant layer, energy-absorbing layer, and fireproof insulation layer to meet the explosion-proof optimization of existing storage tanks and the protection of newly built storage tanks. During installation, the impact-resistant layer and the energy-absorbing layer should avoid overlapping assembly boundaries and be staggered to improve the overall shear resistance of the protective structure. Specifically, the steel grid layer on the entire outer side of the storage tank is assembled and spliced ​​from several prefabricated steel grid pieces, and the assembly boundary (splicing seam) is the position where adjacent grids are assembled and spliced. Similarly, the energy-absorbing layer is also spliced. When covering the steel grid layer, the assembly boundary of the energy-absorbing layer and the splicing seam of the grid layer should not coincide; the two layers should be staggered to achieve staggered splicing.

[0085] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0086] Example 1: Protection of a newly built liquefied hydrocarbon spherical tank with a diameter of 8m

[0087] Based on the installation location of the liquefied hydrocarbon spherical tank, a quantitative assessment of the risks it faces is conducted using methods such as the TNO multi-energy method to obtain quantitative assessment results. These results include the peak incident overpressure and duration of the explosion shock wave experienced by the liquefied hydrocarbon spherical tank, the mass and velocity of the splashed material, and the fire hazard level. A composite protective structure for the liquefied hydrocarbon spherical tank is then designed based on these quantitative assessment results.

[0088] Specifically, the quantitative assessment of the risks faced by the TNO multi-energy method includes: identifying potential explosion sources and explosion receivers for each structure or tank area, determining the volume of obstacles within the explosion source and the effective volume of the obstructed area of ​​the explosion source, modeling each potential explosion source, and assessing the impact of explosion shock wave overpressure and splashes on the liquefied hydrocarbon spherical tank.

[0089] The design of the composite protective structure for the liquefied hydrocarbon spherical tank based on the quantitative assessment results specifically includes:

[0090] The thickness of the impact-resistant layer was determined using numerical simulation based on the mass and velocity of the splashing material.

[0091] Based on the peak incident overpressure and duration of the blast shock wave, the peak incident overpressure and duration of the shock wave are converted into peak reflected pressure and equivalent positive action time using the blast shock wave calculation formula. Based on the peak reflected pressure and equivalent positive action time, the thickness and material parameters of the energy-absorbing layer are determined using the energy-absorbing material decomposition algorithm. Finally, the material to be used is determined based on the determined thickness and material parameters of the energy-absorbing layer.

[0092] The thickness of the fireproof insulation layer is determined by numerical simulation based on the fire hazard level.

[0093] The formula for calculating the explosion shock wave includes:

[0094] P r =C r *P so

[0095] C r =2 + 0.0073P so

[0096] Among them, P so For the peak incident overpressure of the explosion shock wave, P r For peak reflected pressure, C r The reflection coefficient;

[0097] The material parameters include plateau stress and strain rate.

[0098] Specifically, the peak incident overpressure of the explosion shock wave is 20.8 kPa, the duration is 51.7 ms, the mass of the ejected material is 10 kg, the velocity is 50 m / s, the fire hazard rating is level four, the thickness of the fireproof insulation layer is 0.5 cm, the thickness of the impact-resistant layer is 1 cm, and the energy-absorbing layer is a three-layer design with a peak reflected pressure of 44.76 kPa, an equivalent positive impact time of 40.3 ms, and a thickness of 10 cm (4 cm, 3 cm, and 3 cm from the inside out), and a material density of 50-120 kg / m³. 3 The stresses of each platform layer from the inside out are 25KPa, 30KPa, and 35KPa, respectively, with a strain rate greater than 0.3. The material is polyurethane foam.

[0099] Further optimization of the composite protective structure for liquefied hydrocarbon spherical tanks based on the above design method is carried out, such as... Figure 1-5 As shown, the specific composite protective structure for a liquefied hydrocarbon spherical tank includes:

[0100] A tank protective cover is used to protect the tank. The tank protective cover includes an impact-resistant layer in contact with the tank and an energy-absorbing layer disposed on the impact-resistant layer. The impact-resistant layer includes a grid 1 and ceramic pieces 3 disposed in a plurality of unit grids 2 of the grid 1. The surface of the energy-absorbing layer is coated with a fireproof and heat-insulating layer.

[0101] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as good protective effect, high economic benefits, and ease of installation.

[0102] Example 2

[0103] The implementation is similar to Embodiment 1, except that the surface of the ceramic sheet 3 disposed within the unit grid 2 is covered with fibers 4.

[0104] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0105] Example 3

[0106] The implementation follows the same procedure as Example 2, except that the thickness of the vertical bars h1 of the grille 1 is 1 cm and the thickness of the horizontal bars c1 is 0.5 cm.

[0107] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0108] Example 4

[0109] The implementation follows the same procedure as Example 3, except that the unit grid 2 is square, and the side length r1 of the square unit grid 2 is 4.5cm.

[0110] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0111] Example 5

[0112] The same implementation is carried out as in Example 4, except that the fiber 4 is basalt fiber with a thickness of 0.1 cm; and the ceramic sheet 3 is silicon carbide ceramic with a side length of 4.3 cm and a thickness of 0.8 cm.

[0113] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0114] Example 6

[0115] The implementation follows the same procedure as in Example 5, except that both sides of the grid 1 on which the ceramic sheet 3 is disposed are coated with a polyurea layer, the thickness of which is 0.1 cm.

[0116] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0117] Example 7: Protective retrofit of an existing 15m diameter liquefied hydrocarbon spherical tank in a chemical industrial park.

[0118] Based on the installation location of the liquefied hydrocarbon spherical tank, a quantitative assessment of the risks it faces is conducted using methods such as the TNO multi-energy method to obtain quantitative assessment results. These results include the peak incident overpressure and duration of the explosion shock wave experienced by the liquefied hydrocarbon spherical tank, the mass and velocity of the splashed material, and the fire hazard level. A composite protective structure for the liquefied hydrocarbon spherical tank is then designed based on these quantitative assessment results.

[0119] Specifically, the quantitative assessment of the risks faced by the TNO multi-energy method and other methods includes: identifying potential explosion sources and explosion receivers for each structure or tank area, determining the volume of obstacles within the explosion source and the effective volume of the area where the explosion source is obstructed, modeling each potential explosion source, and assessing the impact of explosion shock wave overpressure and splashes on the liquefied hydrocarbon spherical tank.

[0120] The design of the composite protective structure for the liquefied hydrocarbon spherical tank based on the quantitative assessment results specifically includes:

[0121] The thickness of the impact-resistant layer was determined using numerical simulation based on the mass and velocity of the splashing material.

[0122] Based on the peak incident overpressure and duration of the blast shock wave, the peak incident overpressure and duration of the shock wave are converted into peak reflected pressure and equivalent positive action time using the blast shock wave calculation formula. Based on the peak reflected pressure and equivalent positive action time, the thickness and material parameters of the energy-absorbing layer are determined using the energy-absorbing material decomposition algorithm. Finally, the material to be used is determined based on the determined thickness and material parameters of the energy-absorbing layer.

[0123] The thickness of the fireproof insulation layer is determined by numerical simulation based on the fire hazard level.

[0124] The formula for calculating the explosion shock wave includes:

[0125] P r =C r *P so

[0126] C r =2 + 0.0073P so

[0127] Among them, P so For the peak incident overpressure of the explosion shock wave, P r For peak reflected pressure, C r The reflection coefficient;

[0128] The material parameters include plateau stress and strain rate.

[0129] Specifically, the peak incident overpressure of the explosion shock wave is 20.8 kPa, the duration is 51.7 ms, the mass of the ejected material is 10 kg, the velocity is 50 m / s, the fire hazard rating is level four, the thickness of the fireproof insulation layer is 0.5 cm, the thickness of the impact-resistant layer is 1 cm, and the energy-absorbing layer is a three-layer design with a peak reflected pressure of 44.76 kPa, an equivalent positive impact time of 40.3 ms, and a thickness of 10 cm (4 cm, 3 cm, and 3 cm from the inside out), and a material density of 50-120 kg / m³. 3 The stresses of each platform layer from the inside out are 25KPa, 30KPa, and 35KPa, respectively, with a strain rate greater than 0.3. The material is polyurethane foam.

[0130] Further optimization of the composite protective structure for liquefied hydrocarbon spherical tanks based on the above design method is carried out, such as... Figure 1-5 As shown, the specific composite protective structure for a liquefied hydrocarbon spherical tank includes:

[0131] A tank protective cover is used to protect the tank. The tank protective cover includes an impact-resistant layer in contact with the tank and an energy-absorbing layer disposed on the impact-resistant layer. The impact-resistant layer includes a grid 1 and ceramic pieces 3 disposed in a plurality of unit grids 2 of the grid 1. The surface of the energy-absorbing layer is coated with a fireproof and heat-insulating layer.

[0132] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as good protective effect, high economic benefits, and ease of installation.

[0133] Example 8

[0134] Referring to Embodiment 7, the difference is that the surface of the ceramic sheet 3 disposed in the unit grid 2 is covered with fiber 4, and the thickness of the vertical bar h1 of the grid 1 is 1cm, and the thickness of the horizontal bar c1 is 0.5cm.

[0135] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0136] Example 9

[0137] Referring to Embodiment 7, the difference is that the unit grid 2 is square, the side length r1 of the square unit grid 2 is 4.5cm, the fiber 4 is basalt fiber with a thickness of 0.1cm, and the ceramic sheet 3 is silicon carbide ceramic with a side length of 4.3cm and a thickness of 0.8cm.

[0138] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0139] Example 10

[0140] Referring to Embodiment 9, the difference is that both sides of the grid 1 on which the ceramic sheet 3 is disposed are coated with a polyurea layer, and the thickness of the polyurea layer is 0.1 cm.

[0141] Testing has shown that the composite protective structure for liquefied hydrocarbon spherical tanks described in this invention can effectively protect the tank body even when faced with large splashes, offering advantages such as better protection, higher economic benefits, and easier installation.

[0142] The composite protective structure for liquefied hydrocarbon spherical tanks provided by this invention protects the tank body by employing a tank body protective cover comprising an impact-resistant layer and an energy-absorbing layer. The impact-resistant layer includes a grid and ceramic plates disposed within several unit grids of the grid. In practical applications, this structure can effectively ensure the safety of the spherical tank and prevent large splashes and / or explosive shock waves from impacting the tank and causing damage. It has the advantages of easy operation, simple structure, high safety, and cost savings.

[0143] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composite protective structure for a liquefied hydrocarbon spherical tank, characterized in that, Based on the design method of composite protective structure for liquefied hydrocarbon spherical tanks, the composite protective structure for liquefied hydrocarbon spherical tanks includes: Tank protective cover, used to protect the tank, the tank protective cover includes an impact-resistant layer in contact with the tank and an energy-absorbing layer disposed on the impact-resistant layer, the impact-resistant layer includes a grid (1) and ceramic pieces (3) disposed in a plurality of unit grids (2) of the grid (1). The surface of the ceramic sheet (3) disposed within the unit grid (2) is covered with fibers (4); The thickness of the vertical bars of the grille (1) is 0.5-1.5cm, and the thickness of the horizontal bars is 0.2-0.8cm; One or both sides of the grid (1) on which the ceramic sheet (3) is provided are coated with a polyurea layer; The energy-absorbing layer comprises multiple layers arranged in a gradient, with the density and / or plateau stress of each layer decreasing sequentially from the inside to the outside. The design method for the composite protective structure of the liquefied hydrocarbon spherical tank includes: Based on the installation location of the liquefied hydrocarbon spherical tank, a quantitative assessment of the risks it faces is conducted using the TNO multi-energy method to obtain quantitative assessment results. The quantitative assessment results include the peak incident overpressure and duration of the explosion shock wave experienced by the liquefied hydrocarbon spherical tank, the mass and velocity of the splashed material, and the fire hazard level. Based on the quantitative assessment results, a composite protective structure for liquefied hydrocarbon spherical tanks was designed. The quantitative assessment of the risks faced based on the TNO multi-energy method specifically includes: Identify potential explosion sources and explosion receivers for each structure or tank area, determine the volume of obstacles within the explosion source and the effective volume of the obstructed area of ​​the explosion source, model each potential explosion source, and assess the impact of explosion shock wave overpressure and splashes on liquefied hydrocarbon spherical tanks. The design of the composite protective structure for the liquefied hydrocarbon spherical tank based on the quantitative assessment results specifically includes: The thickness of the impact-resistant layer was determined using numerical simulation based on the mass and velocity of the splashing material. Based on the peak incident overpressure and duration of the blast shock wave, the peak incident overpressure and duration of the shock wave are converted into peak reflected pressure and equivalent positive action time using the blast shock wave calculation formula. Based on the peak reflected pressure and equivalent positive action time, the thickness and material parameters of the energy-absorbing layer are determined using the energy-absorbing material decomposition algorithm. Finally, the material to be used is determined based on the determined thickness and material parameters of the energy-absorbing layer. The thickness of the fireproof insulation layer is determined by numerical simulation based on the fire hazard level. The material parameters include density, plateau stress, and strain rate.

2. The composite protective structure for liquefied hydrocarbon spherical tanks according to claim 1, characterized in that, The types of fibers (4) include basalt fiber, glass fiber and carbon fiber; the types of ceramic sheets (3) include alumina ceramic, silicon carbide ceramic and titanium diboride ceramic.

3. The composite protective structure for liquefied hydrocarbon spherical tanks according to claim 1, characterized in that, The unit grid (2) is square, and the side length (r1) of the square unit grid (2) is 4-5cm.

4. The composite protective structure for liquefied hydrocarbon spherical tanks according to claim 1, characterized in that, The energy-absorbing layer is made of energy-absorbing materials, including porous foam materials, honeycomb structures, and superelastic materials.

5. The composite protective structure for liquefied hydrocarbon spherical tanks according to claim 4, characterized in that, The porous foam material includes polyurethane foam and aluminum foam.

6. The composite protective structure for liquefied hydrocarbon spherical tanks according to claim 1, characterized in that, The surface of the energy-absorbing layer is coated with a fireproof and heat-insulating layer.

7. The composite protective structure for liquefied hydrocarbon spherical tanks according to claim 1, characterized in that, The formula for calculating the explosion shock wave includes: in, P so The peak incident overpressure of the explosion shock wave. P r Peak reflected pressure, C r This is the reflection coefficient.

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