Method and system for evaluating equivalent thermal resistance value of intumescent fire-retardant coating for steel structure

Abstract

The present application belongs to the technical field of equivalent thermal resistance value evaluation. An evaluation method and system for the equivalent thermal resistance value of intumescent steel structure fireproof coating are provided. According to the relationship between the temperature of the steel structure protected by the intumescent fireproof coating and the furnace temperature of the fire resistance detection experiment of the fireproof coating, the relationship between the temperature of the steel structure protected by the intumescent fireproof coating and the comprehensive evaluation coefficient is determined. The comprehensive evaluation coefficient is calculated according to the steel density, the specific heat of steel, the cross-sectional shape coefficient and the equivalent thermal resistance value of the fireproof coating. According to the relationship between the temperature of the steel structure protected by the intumescent fireproof coating and the comprehensive evaluation coefficient, the value of the comprehensive evaluation coefficient is determined. According to the determined value of the comprehensive evaluation coefficient and the steel density, the specific heat of steel and the cross-sectional shape coefficient, the final equivalent thermal resistance value of the fireproof coating is obtained, which provides a strong basis for the quality control and optimization of the fireproof coating.

Description

Technical Field

[0001] This invention relates to the field of equivalent thermal resistance evaluation technology, specifically to a method and system for evaluating the equivalent thermal resistance of intumescent fireproof coatings for steel structures. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Steel structure buildings have advantages such as light weight, high strength, fast construction speed, and excellent seismic performance. However, steel has poor fire resistance; under the high temperatures of a fire, the internal temperature of the components rises rapidly, leading to a degradation of the material's elastic modulus, compressive strength, and yield strength. Under the combined action of external forces, structural failure can occur. Therefore, steel structure buildings must be designed with fire protection in mind to delay the temperature rise of the steel during a fire and prevent structural damage. The main fire protection methods for steel structures include applying fire-retardant coatings, covering with fire-resistant boards, and using fire-resistant steel. Among these, applying fire-retardant coatings is currently the most widely used method.

[0004] Based on their fire-retardant mechanisms and coating thickness, fire-retardant coatings for steel structures can be divided into two main categories: intumescent and non-intumescent. Non-intumescent fire-retardant coatings are formulated using inorganic insulating aggregates (such as expanded vermiculite) or reinforcing materials (such as ceramic fibers, glass fibers, etc.) and other fillers. They are low in cost but prone to peeling and have poor aesthetics. Intumescent fire-retardant coatings use polymers with strong adhesion and durability (such as acrylic resins, epoxy resins, etc.) as binders, and add flame retardants (such as ammonium polyphosphate, melamine, pentaerythritol, etc.), pigments, and fillers. When exposed to fire, they expand and foam to form a dense, porous, insulating char layer, delaying the temperature rise of the substrate and providing protection.

[0005] Currently, fire protection design for steel structures primarily determines the critical temperature of components with different stress characteristics by using the cross-sectional strength-load ratio, and then determines the required equivalent thermal resistance for each component using standard temperature rise curves and critical temperatures. For non-intumescent fire-retardant coatings, the equivalent thermal conductivity coefficient is basically the same at different thicknesses, and the difference between different brands is not significant. Therefore, when performing fire protection calculations, the software directly multiplies the equivalent thermal conductivity coefficient by the equivalent thermal resistance to obtain the coating thickness. However, for intumescent fire-retardant coatings, because their thickness changes under high temperatures, and the fire protection principles differ at different expansion stages, the equivalent thermal conductivity coefficient of intumescent fire-retardant coatings varies considerably at different thicknesses. Furthermore, the parameter also varies between different brands. Software calculations generally only provide the equivalent thermal resistance value, and structural engineers must use this value to determine the design value for the fire-retardant coating thickness.

[0006] The quality standard for fire-retardant coatings for steel structures uses fire resistance time as a parameter to characterize the coating's fire resistance. The fire resistance time ranges from 0.5 hours to 3 hours, with each 0.5-hour interval defining a different level. Under the standard temperature rise curve, the maximum bending deformation at mid-span of the steel beam must be less than a specified value at the specified fire resistance time level, and the temperature of the steel beam encased in the fire-retardant coating must also be less than a specified value. Currently, the testing and inspection of fire-retardant coatings for steel structures are all based on the quality standard for fire-retardant coatings for steel structures. Product inspection reports only show the maximum bending deformation at mid-span and the highest temperature of the specimen, without including information on the equivalent thermal resistance of the steel structure's fire-resistant design.

[0007] In reality, steel structural components are in a state of thermo-mechanical coupling under high temperatures during a fire. When the stress state of a component is still more redundant than its ultimate state, that component can withstand higher temperatures than components with less redundancy. However, when using intumescent fire-retardant coatings, this design method must consider material parameters such as equivalent thermal resistance. Therefore, there is currently a disconnect between the structural design of steel structure fire protection and the manufacturers of intumescent fire-retardant coatings. This makes it difficult for structural engineers to directly calculate the coating thickness when using intumescent fire-retardant coatings, causing significant difficulties for fire protection design in engineering projects. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a method and system for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures. Based on the fundamental theory of heat conduction equations and using the test items in the product testing report of intumescent fire-retardant coatings (mid-span bending moment and material temperature of the steel beam coated with fire), the equivalent thermal resistance is calculated. The information in the product testing report is correlated with the equivalent thermal resistance, providing a practical curve for fire-resistant design of structural engineering. This provides a scientific basis and an operable solution for bridging the current disconnect between structural design and the concepts of fire-resistant steel structures and manufacturers of intumescent fire-retardant coatings.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures.

[0011] A method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures includes the following steps:

[0012] To obtain the density of steel, the specific heat of steel, and the cross-sectional shape factor of steel components under thermal conditions;

[0013] Based on the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the comprehensive evaluation coefficient is determined. The comprehensive evaluation coefficient is calculated based on the steel density, steel specific heat, cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating.

[0014] Based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient, the value of the comprehensive evaluation coefficient is determined. Based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, specific heat of the steel, and cross-sectional shape coefficient, the final equivalent thermal resistance value of the fire retardant coating is obtained.

[0015] Secondly, the present invention provides an evaluation system for the equivalent thermal resistance of intumescent fireproof coatings for steel structures.

[0016] A system for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures, comprising:

[0017] The data acquisition unit is configured to acquire steel density, steel specific heat, and the cross-sectional shape factor of steel components under thermal conditions.

[0018] The first calculation unit is configured to: determine the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating. The comprehensive evaluation coefficient is calculated based on the steel density, the specific heat of the steel, the cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating.

[0019] The second calculation unit is configured to: determine the value of the comprehensive evaluation coefficient based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient; and obtain the final equivalent thermal resistance value of the fire retardant coating based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, specific heat of the steel, and cross-sectional shape coefficient.

[0020] Thirdly, the present invention provides a computer device, comprising: a processor and a computer-readable storage medium;

[0021] A processor, adapted to execute computer programs;

[0022] A computer-readable storage medium storing a computer program, which, when executed by the processor, implements the method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures as described in the first aspect of the present invention.

[0023] Fourthly, the present invention provides a computer-readable storage medium storing a computer program adapted to be loaded by a processor and executed as described in the first aspect of the present invention for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures.

[0024] Fifthly, the present invention provides a computer program product comprising a computer program that, when executed by a processor, implements the method for evaluating the equivalent thermal resistance of intumescent fireproof coatings for steel structures as described in the first aspect of the present invention.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention innovatively proposes a method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures. From the perspective of basic data acquisition, it accurately obtains the steel density, specific heat, and cross-sectional shape factor of steel components under thermal conditions, deeply analyzing the inherent properties of the steel structure. The steel density and specific heat determine its heat storage and transfer characteristics, while the cross-sectional shape factor reflects the unique influence of component shape on heat exchange. Comprehensive consideration of these key parameters provides detailed and accurate basic data for subsequent evaluation, ensuring that the evaluation results truly reflect the actual situation. In terms of theoretical model construction, it cleverly establishes the relationship between the temperature of the steel structure under the protection of the intumescent fire-retardant coating and the comprehensive evaluation coefficient. The comprehensive evaluation coefficient cleverly integrates the multi-dimensional characteristics of the steel structure and the fire-retardant coating... The innovative relationship between the equivalent thermal resistance of fire-retardant coatings and actual steel structure temperature data provides a solid theoretical foundation for deriving the equivalent thermal resistance of fire-retardant coatings, making the evaluation process more scientific and logical. In practical applications, this relationship is used to determine the comprehensive evaluation coefficient and further calculate the equivalent thermal resistance of the fire-retardant coating. The operation process is clear, highly feasible, and efficiently transforms theory into practical application. This invention not only accurately evaluates the performance of fire-retardant coatings, providing a strong basis for quality control and optimization, but also helps engineers rationally select fire-retardant coatings in the fire protection design of steel structure buildings, improving the fire safety performance of buildings and protecting the lives and property of personnel. It has extremely high practical value and broad application prospects.

[0027] This invention establishes the relationship between steel temperature under fire-retardant coating protection and a comprehensive evaluation coefficient, accurately obtaining steel density, specific heat, and cross-sectional shape factor under thermal conditions. This allows for a deep understanding of the inherent thermal characteristics of the steel structure. Density and specific heat determine its heat capacity and heat transfer ability, while the cross-sectional shape factor reflects the influence of geometry on heat exchange, thus laying a solid data foundation for evaluation. Based on the relationship between steel temperature under fire-retardant coating protection and the furnace temperature for fire resistance testing, a link is established between steel temperature and a comprehensive evaluation coefficient. This comprehensive evaluation coefficient integrates the steel structure characteristics with the equivalent thermal resistance value of the fire-retardant coating to be determined. This relationship closely connects actual temperature monitoring with theoretical evaluation, providing scientific theoretical guidance for the evaluation. The comprehensive evaluation coefficient is determined based on the above relationship. The method involves calculating the equivalent thermal resistance value by combining the obtained steel structure parameters. The process is clear and highly operable, efficiently transforming theory into practical evaluation results. This method accurately assesses the performance of fire-retardant coatings, providing crucial information for coating quality control and performance optimization. In the fire protection design of steel structure buildings, it helps engineers rationally select fire-retardant coatings and design appropriate thicknesses, thereby improving the building's fire safety level. Simultaneously, this solution points the way for the research and improvement of fire-retardant coatings, promoting the development of fire-retardant coating technology, ensuring the safety of steel structure buildings in dangerous situations such as fires, and effectively protecting the lives and property of personnel. It has significant application value and broad development prospects in the field of building fire protection.

[0028] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0030] Figure 1 A flowchart illustrating an exemplary embodiment of the present invention for evaluating the equivalent thermal resistance of an intumescent fire-retardant coating for steel structures;

[0031] Figure 2 A graph showing the elastic modulus of steel and its corresponding temperature is provided as an exemplary embodiment of the present invention.

[0032] Figure 3 A diagram showing the steel temperature and corresponding equivalent thermal resistance is provided as an exemplary embodiment of the present invention.

[0033] Figure 4 A flowchart illustrating an exemplary embodiment of the present invention provides a system for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures.

[0034] Figure 5 A schematic diagram of a computer device provided for an exemplary embodiment of the present invention. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0036] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0037] This invention proposes a method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures. The technical terms and related concepts involved in this solution are briefly introduced below:

[0038] Lumped heat capacity method: According to the Fourier heat conduction equation, the temperature change inside the heat transfer body is proportional to the temperature difference between the inside and outside of the heat transfer body. The lumped heat capacity method is a simplified form of the Fourier heat conduction equation. It assumes that the internal thermal resistance of the heat conductor is much smaller than the surface convection thermal resistance, that is, the internal temperature of the heat conductor is uniform and there is no spatial difference.

[0039] Newton's iteration method: As an efficient numerical method for solving nonlinear equations, it is especially suitable for transcendental equations, such as equations containing trigonometric functions, exponential functions, logarithmic functions, etc., which cannot be solved analytically by algebraic transformations. The basic idea is to approximate the root of the equation by using the linear part (tangent) of the Taylor expansion of the function.

[0040] The method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures, specifically, is as follows: Figure 1 As shown, it includes:

[0041] S101: Obtain the steel density, specific heat of steel, and cross-sectional shape factor of steel components under thermal conditions;

[0042] S102: Based on the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, determine the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the comprehensive evaluation coefficient. The comprehensive evaluation coefficient is calculated based on the steel density, steel specific heat, cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating.

[0043] S103: Based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient, determine the value of the comprehensive evaluation coefficient. Based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, steel specific heat and cross-sectional shape coefficient, obtain the final equivalent thermal resistance value of the fire retardant coating.

[0044] More specifically, the present invention mainly comprises two parts: the first part is the temperature calculation of the specimen (i.e., steel beam) in the fire resistance test of fire-resistant coating for steel structures, and the second part is the calculation of the equivalent thermal resistance of the fire-resistant coating.

[0045] In the specimen temperature calculation for the fire resistance test of fire-retardant coatings on steel structures in Part 1, the temperature of a specimen coated with a certain thickness of fire-retardant coating in a high-temperature furnace under a specified fire resistance rating is calculated using fire-retardant coating quality inspection test methods and mechanical theory. The main processes include the following:

[0046] The fire resistance performance test of the fire-retardant coating for steel structures used Q235 steel as the substrate, and steel beams were used for fire exposure and loading. The steel beams were HN400×200 hot-rolled H-beams or I36b hot-rolled I-beams, with a fire exposure length of [missing information]. The loading length should be no less than 4000 mm. The loading method is four-point loading, meaning the loading zone of the specimen is a pure bending segment, and the loading length... The experimental loading amount was increased by a maximum of 100mm at each end of the fire-exposed length. The design bending moment limit is 60% of the design bending moment limit value. The following requirements should be met:

[0047] (1);

[0048] in, The strength reduction factor can be taken as 0.9. For bending strength, Section modulus for bending. Coefficient of plastic development of section. When the ratio of the free overhang width of the compression flange of the beam to its thickness is greater than and not more than At that time, take .

[0049] Fire resistance tests determine the fire resistance rating of fire-retardant coatings; specifically, within the time specified for the fire resistance rating, the maximum deflection of a steel beam coated with a fire-retardant coating should not exceed a specified value. ,in Given the height of the steel beam, the maximum deflection at mid-span can be obtained using mechanical methods. c and elastic modulus Relationship:

[0050] (2);

[0051] in, Let be the moment of inertia of the steel beam section.

[0052] In the refractory test, as the furnace temperature increased, the elastic modulus of the steel beam decreased. The deflection gradually decreases and then gradually increases. Under high temperature, the steel beam reaches its maximum deflection at mid-span. c At that time, the elastic modulus of steel is:

[0053] (3);

[0054] The final value within the parentheses is 60% of the design bending moment limit value.

[0055] Calculate when the elastic modulus of steel reaches The specific temperature of the steel at that time includes:

[0056] (4);

[0057] in, The elastic modulus of Q235 steel substrate at room temperature is obtained by... Substituting into the above equation, we can solve it using Newton's iteration method to obtain... This means that the mid-span deflection of the steel beam reaches [a certain value]. c The internal temperature of the steel.

[0058] The method for solving the above equation using Newton's iteration method is as follows:

[0059] (5);

[0060] (6).

[0061] The value is generally between 400℃ and 600℃, and an initial value of 500℃ can be used for calculation.

[0062] (7);

[0063] Until The value reaches 10 -5 The above precision can be achieved by using the appendix when it is inconvenient to calculate using Newton's iteration method. Figure 2 Curve, via Found value.

[0064] The quality inspection test for fire-retardant coatings also requires that thermocouple wires be extended from the surface of the steel beam substrate under the fire-retardant coating to measure the highest temperature reached by the steel during the test, ensuring that it does not exceed the specified value. Theoretically, when the steel beam reaches its maximum deflection at mid-span during the test, the steel material should simultaneously reach its highest temperature; this measured value should equal the value calculated using Newton's iteration method. In reality, both the experimental measurements of maximum deflection and maximum temperature have inherent errors. When the fire-retardant coating quality inspection report provides both the maximum deflection and maximum temperature at mid-span of the steel beam, these two values ​​should be used to comprehensively estimate the temperature. (For example, to find the mean).

[0065] In this implementation, the second part is the calculation of the equivalent thermal resistance of the fire-retardant coating on the steel structure, which is based on the temperature of the steel material (i.e., the expansion-type steel structure). Based on the standard temperature rise curve of the furnace and the fundamental theory of the lumped heat capacity method, the equivalent thermal resistance of the fire-retardant coating is calculated, which mainly includes the following process:

[0066] Assume the furnace temperature for the fire resistance test of the fire-retardant coating is... The equivalent thermal resistance of the fire-retardant coating applied to the surface of the steel substrate is [value missing], and the temperature of the steel under the protection of the fire-retardant coating is [value missing]. Since steel is a good conductor of heat, the internal temperature gradient of the steel can be ignored, that is, it is assumed that the internal temperature field of the steel is a uniform field. The process of heat transfer from the high-temperature experimental furnace to the steel is described by the lumped heat capacity method:

[0067] (8);

[0068] in, The variable is time, and the unit is seconds (s). This is the density of steel, taken as 7850 kg / m³. 3 , The specific heat of steel is taken as 0.502 × 10⁻⁶. 3 J / (kg·℃), It is the section shape factor of steel components under thermal conditions; for HN400×200 hot-rolled H-beams, it is 161m.-1 I36b hot-rolled I-beams are 126m in length. -1 .

[0069] Let the initial conditions be Steel temperature in seconds Under this condition, the above equation is modified to:

[0070] (9);

[0071] (10);

[0072] The furnace temperature for the refractory test was determined using the ISO standard temperature rise curve, i.e.:

[0073] (11);

[0074] Based on the above formula, we can obtain:

[0075] (12);

[0076] The temperature of the steel obtained from the fire resistance test is obtained from the first part. Then, solve using the above formula. This process involves solving the transcendental equation, which should be calculated using Newton's iteration method. Let:

[0077] (13);

[0078] (14);

[0079] in, The value is typically a few ten-thousandths to a few thousandths. An initial value of 0.0001 is used, and an iterative method is employed for calculation. value:

[0080] (15);

[0081] Until The value reaches 10 -5 The above precision is required. Then, based on the steel density... Specific heat and cross-sectional shape factor Calculate the equivalent thermal resistance. When it is inconvenient to use Newton's iteration method for calculation, an auxiliary method can be used. Figure 3 The equivalent thermal resistance is obtained from the curve. Fire resistance ratings are generally divided into six levels: 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, and 3 hours. After collecting the brand's fire resistance rating test reports to determine the equivalent thermal resistance at the six thicknesses, the thicknesses corresponding to other equivalent thermal resistances are determined using linear interpolation.

[0082] This implementation provides the following example: Assume an imported outdoor intumescent fire-retardant coating for steel structures, product number GT-WRP-F. P 2.00-XXXX, small retail price 80 yuan / kg, fire resistance test report shows fire retardant coating thickness 3.0mm, fire resistance test time 2 hours, maximum deflection at mid-span of specimen during test 14.5mm, highest specimen temperature 530℃. Fire resistance test steel beam fire-exposed length. Typically 4000mm, loading length The diameter is 4400mm, mostly using I36b I-beams, with the following cross-sectional parameters: , .

[0083] Calculate the elastic modulus of the steel at the maximum deflection at mid-span:

[0084] (16);

[0085] get:

[0086] (17);

[0087] Solve the following equation using Newton's iterative method:

[0088] (18);

[0089] get The reference specimen's thermocouple temperature was 530℃. (Based on comprehensive analysis...) .

[0090] Solve the following equation using Newton's iterative method:

[0091] (19);

[0092] The equivalent thermal resistance R is obtained as 0.2238℃ / W, which means that the equivalent thermal resistance of this brand of fireproof coating is 0.2238℃ / W when the thickness is 3.0 mm. The equivalent thermal resistance values ​​for other thicknesses are calculated in the same way. When the required equivalent thermal resistance value of a certain component is obtained, the coating thickness is calculated by linear interpolation.

[0093] Table 1 shows the fire resistance performance data from the product quality test reports for other fire resistance ratings of the aforementioned brand of fire-retardant coatings. The report indicates that the experimental steel beams used were I36b I-beams, and the length exposed to fire was... =4000mm, loading length =4200mm, total external load 207kN, and I36b I-beam section parameters are also found. =920.8cm 3 , =16574cm 4 .

[0094] Table 1: Fire resistance performance of an intumescent fire retardant coating of a certain brand.

[0095]

[0096] The equivalent thermal resistance of the example product was tested by the brand manufacturer, and the data is shown in Table 2.

[0097] Table 2: Verification results.

[0098]

[0099] By comparing the data in Table 2 with those in Table 1, it can be seen that the error of the method of the present invention does not exceed 12%. When estimating the equivalent thermal resistance of fire-retardant coatings according to the method of the present invention, the calculation results are generally too small and too conservative. It can be applied to the calculation of the thickness of intumescent fire-retardant coatings in engineering fire protection design.

[0100] Figure 4 A system for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures is shown, comprising:

[0101] The data acquisition unit 401 is configured to acquire the steel density, the steel specific heat, and the cross-sectional shape factor of the steel component under thermal conditions.

[0102] The first calculation unit 402 is configured to: determine the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, wherein the comprehensive evaluation coefficient is calculated based on the steel density, the specific heat of the steel, the cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating.

[0103] The second calculation unit 403 is configured to: determine the value of the comprehensive evaluation coefficient based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient; and obtain the final equivalent thermal resistance value of the fire retardant coating based on the determined value of the comprehensive evaluation coefficient, the steel density, the steel specific heat and the cross-sectional shape coefficient.

[0104] It is understood that the aforementioned units can be individually or entirely merged into one or more other units, or some of the units can be further divided into multiple functionally smaller units. This achieves the same operation without affecting the technical effects of the embodiments of this application. The aforementioned units are based on logical functional division. In practical applications, the function of one unit can be implemented by multiple units, or the function of multiple units can be implemented by one unit. In other embodiments of this application, the system may also include other units. In practical applications, these functions can also be implemented with the assistance of other units, and can be implemented collaboratively by multiple units.

[0105] According to another embodiment of this application, the system described in this embodiment can be constructed by running a computer program (including program code) capable of performing the steps involved in the corresponding method of the present invention on a general-purpose computing device, such as a computer, which includes processing elements and storage elements such as a central processing unit (CPU), random access memory (RAM), and read-only memory (ROM). The computer program can be recorded on, for example, a computer-readable recording medium, loaded into the aforementioned computing device through the computer-readable recording medium, and run therein.

[0106] Figure 5 A computer device is shown, which includes a processor 501, a communication interface 502, and a computer-readable storage medium 503. The processor 501, communication interface 502, and computer-readable storage medium 503 can be connected via a bus or other means.

[0107] The communication interface 502 is used to receive and send data. The computer-readable storage medium 503 can be stored in the memory of the electronic device. The computer-readable storage medium 503 is used to store computer programs, which include program instructions. The processor 501 is used to execute the program instructions stored in the computer-readable storage medium 503.

[0108] The processor 501 is the computing and control core of the electronic device. It is suitable for implementing one or more instructions, specifically for loading and executing one or more instructions to achieve the corresponding method flow or corresponding function.

[0109] The processor 501 is configured to perform the following process:

[0110] To obtain the density of steel, the specific heat of steel, and the cross-sectional shape factor of steel components under thermal conditions;

[0111] Based on the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the comprehensive evaluation coefficient is determined. The comprehensive evaluation coefficient is calculated based on the steel density, steel specific heat, cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating.

[0112] Based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient, the value of the comprehensive evaluation coefficient is determined. Based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, specific heat of the steel, and cross-sectional shape coefficient, the final equivalent thermal resistance value of the fire retardant coating is obtained.

[0113] This invention also provides a computer-readable storage medium, which is a memory device in an electronic device for storing programs and data. It is understood that the computer-readable storage medium here may include both built-in storage media in the electronic device and extended storage media supported by the electronic device. The computer-readable storage medium provides storage space for storing the processing system of the electronic device.

[0114] Furthermore, this storage space also contains one or more instructions suitable for loading and execution by the processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM memory or unstable memory, such as at least one disk storage device; optionally, it can also be at least one computer-readable storage medium located remotely from the aforementioned processor.

[0115] In one embodiment, the computer-readable storage medium stores one or more instructions; the processor loads and executes the one or more instructions stored in the computer-readable storage medium to perform the following process:

[0116] To obtain the density of steel, the specific heat of steel, and the cross-sectional shape factor of steel components under thermal conditions;

[0117] Based on the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the comprehensive evaluation coefficient is determined. The comprehensive evaluation coefficient is calculated based on the steel density, steel specific heat, cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating.

[0118] Based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient, the value of the comprehensive evaluation coefficient is determined. Based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, specific heat of the steel, and cross-sectional shape coefficient, the final equivalent thermal resistance value of the fire retardant coating is obtained.

[0119] The present invention also provides a computer program product or computer program comprising computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the following process:

[0120] To obtain the density of steel, the specific heat of steel, and the cross-sectional shape factor of steel components under thermal conditions;

[0121] Based on the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the comprehensive evaluation coefficient is determined. The comprehensive evaluation coefficient is calculated based on the steel density, steel specific heat, cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating.

[0122] Based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient, the value of the comprehensive evaluation coefficient is determined. Based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, specific heat of the steel, and cross-sectional shape coefficient, the final equivalent thermal resistance value of the fire retardant coating is obtained.

[0123] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0124] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic cable, digital cable) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data processing device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0125] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures, characterized in that, Includes the following processes: To obtain the density of steel, the specific heat of steel, and the cross-sectional shape factor of steel components under thermal conditions; Based on the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, the relationship between the temperature of the steel structure under the protection of intumescent fire retardant coating and the comprehensive evaluation coefficient is determined. The comprehensive evaluation coefficient is calculated based on the steel density, steel specific heat, cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating. Based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient, the value of the comprehensive evaluation coefficient is determined. Based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, specific heat of the steel, and cross-sectional shape coefficient, the final equivalent thermal resistance value of the fire retardant coating is obtained.

2. The method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures as described in claim 1, characterized in that, The relationship between the temperature of steel under the protection of intumescent fire-retardant coating and the furnace temperature in the fire resistance test of the fire-retardant coating is as follows: ； in, Represents time, Represents the density of steel. It is the specific heat of steel. The cross-sectional shape factor represents the thermal condition of an expansion-type steel structure. represent The steel temperature is constantly protected by fire-retardant coating. represent The furnace temperature for the fire resistance test of the fire-retardant coating at any given time. Represents equivalent thermal resistance.

3. The method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures as described in claim 2, characterized in that, The overall evaluation coefficient is: .

4. The method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures as described in claim 3, characterized in that, The relationship between the temperature of steel under the protection of intumescent fire-retardant coating and the comprehensive evaluation coefficient is as follows: ； in, This represents the method used to iterate through time intervals in integral operations. Variables.

5. The method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures as described in any one of claims 1-4, characterized in that, Based on the relationship between the temperature of steel under the protection of intumescent fire-retardant coating and the comprehensive evaluation coefficient, the value of the comprehensive evaluation coefficient is calculated using the Newton-Raphson iteration method.

6. The method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures as described in any one of claims 1-4, characterized in that, Obtaining the temperature of steel structures under the protection of intumescent fire-retardant coatings, including: Obtain the elastic modulus of the steel material when the steel beam reaches its maximum deflection at mid-span under high temperature. The relationship between the elastic modulus of steel and the temperature of the steel structure under the protection of intumescent fire retardant coating was determined, and the temperature of the steel structure under the protection of intumescent fire retardant coating was determined by Newton's iterative method.

7. A system for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures, characterized in that, include: The data acquisition unit is configured to acquire steel density, steel specific heat, and the cross-sectional shape factor of steel components under thermal conditions. The first calculation unit is configured to: determine the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating, based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the furnace temperature of the fire resistance test of the fire retardant coating. The comprehensive evaluation coefficient is calculated based on the steel density, the specific heat of the steel, the cross-sectional shape factor and the equivalent thermal resistance of the fire retardant coating. The second calculation unit is configured to: determine the value of the comprehensive evaluation coefficient based on the relationship between the temperature of the steel structure under the protection of the intumescent fire retardant coating and the comprehensive evaluation coefficient; and obtain the final equivalent thermal resistance value of the fire retardant coating based on the determined value of the comprehensive evaluation coefficient, as well as the steel density, specific heat of the steel, and cross-sectional shape coefficient.

8. A computer device, characterized in that, include: Processor and computer-readable storage media; A processor, adapted to execute computer programs; A computer-readable storage medium storing a computer program, which, when executed by the processor, implements the method for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program adapted to be loaded by a processor and executed as described in any one of claims 1 to 6 for evaluating the equivalent thermal resistance of intumescent fire-retardant coatings for steel structures.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method for evaluating the equivalent thermal resistance of intumescent fireproof coatings for steel structures as described in any one of claims 1 to 6.

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