A method for detecting temperature field distribution of special-shaped metal roof

Abstract

The present invention discloses a temperature field distribution detection method for a special-shaped metal roof. The special-shaped metal roof is discretized and cut into equidistant three-dimensional points by grid cutting, thereby realizing refined temperature monitoring. When calculating the temperature, geometric parameters, external factors and various heat transfer modes, including solar radiation, heat convection and long-wave radiation, are comprehensively considered to ensure the comprehensiveness and accuracy of the calculation. The thermal environment of the metal roof is truly reflected by accurately calculating the solar radiation intensity and the heat flux density of heat convection, as well as the heat flux density of long-wave radiation. Finally, the discrete temperature values ​​are converted into a continuous temperature field diagram by interpolation processing, thereby intuitively displaying the temperature distribution of the special-shaped metal roof.

Description

Technical Field

[0001] The invention relates to the technical field of temperature detection of special-shaped metal roofs, and in particular to a method for detecting temperature field distribution of special-shaped metal roofs. Background Art

[0002] With the diversification of architectural design and technological advancement, special-shaped metal roofs have been widely used in modern buildings due to their good structural performance, durability and aesthetics. However, due to their complex shapes, large surface areas and exposure to the natural environment, the temperature field distribution of these special-shaped metal roofs is affected by many factors, such as solar radiation, ambient temperature, wind speed and direction, and the thermal properties of their own materials. This complexity makes it difficult for traditional temperature measurement methods to accurately obtain their comprehensive temperature field distribution, which brings challenges to the energy management, thermal performance evaluation and structural optimization of buildings.

[0003] Traditional temperature measurement methods, such as point thermometers and infrared thermal imagers, can reflect the temperature conditions of metal roofs to a certain extent, but they have many limitations. Point thermometers can only measure the temperature of local areas and cannot fully reflect the temperature field distribution of the entire roof; and although infrared thermal imagers can obtain surface temperature distribution images, for metal roofs with complex shapes, their measurement precision and accuracy are often affected by factors such as occlusion and reflection. Summary of the invention

[0004] In view of this, the present invention proposes a method for detecting the temperature field distribution of a special-shaped metal roof, which can solve the defects of the prior art that the temperature field distribution of the entire roof cannot be fully reflected and the measurement precision and accuracy are relatively poor.

[0005] The technical solution of the present invention is achieved in this way:

[0006] A method for detecting temperature field distribution of a special-shaped metal roof, specifically comprising:

[0007] Discretize the special-shaped metal roof, use square grid or triangle grid to cut the continuous metal roof surface into equidistant three-dimensional space points, and obtain the geometric parameters of each discrete point;

[0008] Calculate the relative position relationship between the discrete point and the sun according to the geographical location, season, time and geometric parameters of the discrete point itself;

[0009] According to the relative position relationship between the discrete point and the sun, the radiation intensity of the sun to the discrete point is calculated;

[0010] Calculate the heat flux density of thermal convection between discrete points and the environment;

[0011] Calculate the long-wave radiation heat flux density caused by the long-wave radiation from the ground and the sky;

[0012] According to the radiation intensity, heat convection heat flux density and long-wave radiation heat flux density of the discrete points, the temperature value of each discrete point is obtained;

[0013] Through interpolation processing, the temperature values ​​of all discrete points are combined to obtain the temperature field distribution of the special-shaped metal roof.

[0014] As a further optional solution of the temperature field distribution detection method of the special-shaped metal roof, the special-shaped metal roof is discretized, and the continuous metal roof surface is cut into equidistant three-dimensional space points using a square grid or a triangular grid to obtain the geometric parameters of each discrete point, which specifically include:

[0015] Determine the size of the grid unit based on the boundary shape and size of the metal roof;

[0016] Get the surface geometry information of the metal roof;

[0017] According to the surface geometry information of the metal roof and the size requirements of the mesh unit, the CAD software is used to automatically generate the mesh;

[0018] After the mesh is generated, the three-dimensional space coordinates of each mesh vertex are recorded;

[0019] According to the three-dimensional space coordinates of each mesh vertex, the normal vector of each mesh vertex is calculated;

[0020] The three-dimensional space coordinates and normal vector of each mesh vertex are output to obtain the geometric parameters of each discrete point.

[0021] As a further optional solution of the temperature field distribution detection method of the special-shaped metal roof, the relative position relationship between the discrete point and the sun is calculated according to the geographical location, season, time and geometric parameters of the discrete point itself, which specifically includes:

[0022] Acquire basic data of discrete points, wherein the basic data includes geographical location, time information, season information and geometric parameters of the discrete points;

[0023] Calculating the relative position relationship between the discrete points and the sun based on the basic data of the discrete points, wherein the position of the sun includes the solar declination angle, solar hour angle, solar altitude angle and azimuth angle;

[0024] Obtaining the structural surface azimuth;

[0025] The solar incidence angle is calculated based on the basic data of the discrete points and the relative position relationship between the discrete points and the sun.

[0026] As a further optional solution of the temperature field distribution detection method of the special-shaped metal roof, the calculation of the radiation intensity of the sun to the discrete point based on the relative position relationship between the discrete point and the sun specifically includes:

[0027] According to the relative position relationship between the discrete point and the sun, the direct solar radiation intensity of the discrete point is calculated;

[0028] According to the direct solar radiation intensity at discrete points, the solar scattering intensity at discrete points is calculated;

[0029] According to the direct solar radiation intensity and solar scattering intensity, the surface reflection intensity of discrete points is calculated;

[0030] The solar radiation intensity at discrete points is calculated based on the solar direct radiation intensity, solar scattering intensity and surface reflection intensity.

[0031] As a further optional solution of the temperature field distribution detection method of the special-shaped metal roof, the heat flux density of the heat convection between the discrete points and the environment is calculated, specifically including:

[0032] Get discrete point temperature, ambient temperature and wind speed;

[0033] The convective heat transfer coefficient is calculated based on the wind speed and the geometric shape of the surface at the discrete points;

[0034] The convection heat flux density is calculated based on the discrete point temperature, ambient temperature and convection heat transfer coefficient.

[0035] As a further optional solution of the temperature field distribution detection method of the special-shaped metal roof, the calculation of the long-wave radiation heat flux density caused by the long-wave radiation from the ground and the sky specifically includes:

[0036] Get ground temperature, sky temperature, ground emissivity and sky emissivity;

[0037] Calculate the ground radiation power density based on the ground temperature and ground emissivity;

[0038] Calculate the sky radiation power density based on the sky temperature and sky emissivity;

[0039] The long-wave radiation heat flux density is calculated based on the ground radiation power density and the sky radiation power density.

[0040] As a further optional scheme of the temperature field distribution detection method of the special-shaped metal roof, the temperature value of each discrete point is obtained according to the radiation intensity, thermal convection heat flux density and long-wave radiation heat flux density of the discrete point, which specifically includes:

[0041] The mathematical model of the thermal equilibrium state of discrete points is established by incorporating the radiation intensity, thermal convection heat flux density and long-wave radiation heat flux density of discrete points into the thermal equilibrium equation.

[0042] Solve the mathematical model to obtain the temperature value of each discrete point.

[0043] As a further optional solution of the temperature field distribution detection method of the special-shaped metal roof, the temperature values ​​of all discrete points are combined through interpolation processing to obtain the temperature field distribution of the special-shaped metal roof, which specifically includes:

[0044] Identify and handle outliers in the temperature values ​​of all discrete points;

[0045] The entire data set is interpolated according to the Kriging interpolation method to generate a continuous temperature field;

[0046] The continuous temperature field data is visualized as a temperature field graph to show the temperature distribution of the special-shaped metal roof.

[0047] A computing device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for detecting the temperature field distribution of a special-shaped metal roof are implemented.

[0048] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for detecting the temperature field distribution of a special-shaped metal roof.

[0049] The beneficial effects of the present invention are as follows: by discretizing the special-shaped metal roof and cutting it into equidistant three-dimensional space points using a square grid or a triangular grid, the metal roof can be ensured to be subjected to refined temperature monitoring. This method can capture subtle temperature changes on the surface of the metal roof and improve the accuracy of the temperature field distribution. When calculating the temperature value of the discrete point, not only the geometric parameters of the discrete point itself are considered, but also external factors such as the geographical location, season, time, and various heat transfer modes such as solar radiation, heat convection, and long-wave radiation are comprehensively considered. This comprehensive consideration makes the calculation of the temperature value closer to the actual situation and improves the reliability of the temperature field distribution. By calculating the relative position of the discrete point with the sun, the temperature of the metal roof can be accurately detected. The position relationship is calculated, and then the radiation intensity of the sun on the discrete points is calculated. This method can accurately reflect the impact of solar radiation on the temperature of the metal roof. In addition to solar radiation, the heat convection heat flux density between the discrete points and the environment, as well as the long-wave radiation heat flux density caused by the long-wave radiation of the ground and the sky are also calculated. The comprehensive consideration of these heat transfer methods makes the calculation of temperature values ​​more comprehensive and accurate, and can more truly reflect the thermal environment of the metal roof. Through interpolation processing, the temperature values ​​of all discrete points are combined to obtain the temperature field distribution of the special-shaped metal roof. This method can convert discrete temperature data into a continuous temperature field diagram, which is convenient for intuitively displaying and analyzing the temperature distribution of the metal roof. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 A schematic flow chart of a method for detecting temperature field distribution of a special-shaped metal roof provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] like Figure 1 The method for detecting the temperature field distribution of a special-shaped metal roof specifically comprises:

[0054] Discretize the special-shaped metal roof, use square grid or triangle grid to cut the continuous metal roof surface into equidistant three-dimensional space points, and obtain the geometric parameters of each discrete point;

[0055] Calculate the relative position relationship between the discrete point and the sun according to the geographical location, season, time and geometric parameters of the discrete point itself;

[0056] According to the relative position relationship between the discrete point and the sun, the radiation intensity of the sun to the discrete point is calculated;

[0057] Calculate the heat flux density of thermal convection between discrete points and the environment;

[0058] Calculate the long-wave radiation heat flux density caused by the long-wave radiation from the ground and the sky;

[0059] According to the radiation intensity, heat convection heat flux density and long-wave radiation heat flux density of the discrete points, the temperature value of each discrete point is obtained;

[0060] Through interpolation processing, the temperature values ​​of all discrete points are combined to obtain the temperature field distribution of the special-shaped metal roof.

[0061] In this embodiment, by discretizing the special-shaped metal roof and cutting it into equidistant three-dimensional space points using a square grid or a triangular grid, it is possible to ensure refined temperature monitoring of the metal roof. This method can capture subtle temperature changes on the surface of the metal roof and improve the accuracy of the temperature field distribution. When calculating the temperature value of the discrete point, not only the geometric parameters of the discrete point itself are considered, but also external factors such as geographical location, season, time, and various heat transfer modes such as solar radiation, heat convection, and long-wave radiation are comprehensively considered. This comprehensive consideration makes the calculation of the temperature value closer to the actual situation and improves the reliability of the temperature field distribution. By calculating the relative position of the discrete point to the sun, the temperature of the metal roof can be accurately detected. The position relationship is then used to calculate the radiation intensity of the sun on the discrete points. This method can accurately reflect the impact of solar radiation on the temperature of the metal roof. In addition to solar radiation, the heat convection heat flux density between the discrete points and the environment, as well as the long-wave radiation heat flux density caused by the long-wave radiation from the ground and the sky are also calculated. The comprehensive consideration of these heat transfer methods makes the calculation of the temperature value more comprehensive and accurate, and can more truly reflect the thermal environment of the metal roof. Through interpolation processing, the temperature values ​​of all discrete points are combined to obtain the temperature field distribution of the special-shaped metal roof. This method can convert discrete temperature data into a continuous temperature field diagram, which is convenient for intuitively displaying and analyzing the temperature distribution of the metal roof.

[0062] Preferably, the special-shaped metal roof is discretized, and the continuous metal roof surface is cut into equidistant three-dimensional space points using a square grid or a triangular grid to obtain the geometric parameters of each discrete point, which specifically include:

[0063] Determine the size of the grid unit based on the boundary shape and size of the metal roof;

[0064] Get the surface geometry information of the metal roof;

[0065] According to the surface geometry information of the metal roof and the size requirements of the mesh unit, the CAD software is used to automatically generate the mesh;

[0066] After the mesh is generated, the three-dimensional space coordinates of each mesh vertex are recorded;

[0067] According to the three-dimensional space coordinates of each mesh vertex, the normal vector of each mesh vertex is calculated;

[0068] The three-dimensional space coordinates and normal vector of each mesh vertex are output to obtain the geometric parameters of each discrete point.

[0069] In this embodiment, determining the size of the grid unit is the basis of discretization processing. By reasonably determining the size of the grid unit, the calculation accuracy can be guaranteed while controlling the amount of calculation. The size of the grid unit should be considered comprehensively based on factors such as the complexity of the metal roof, the accuracy of the required temperature field distribution, and computing resources. Accurately obtaining the surface geometry information of the metal roof is a prerequisite for subsequent grid generation and temperature calculation, which usually requires measurement, CAD modeling, or three-dimensional scanning to ensure the accuracy and integrity of the surface geometry information. Using the powerful functions of CAD software, a grid that meets the requirements can be automatically and efficiently generated. This method not only improves the accuracy and efficiency of grid generation, but also reduces errors caused by human factors. The generated mesh should fit the curved surface of the metal roof tightly to ensure the accuracy of subsequent temperature calculations. The three-dimensional spatial coordinates of the mesh vertices are the basic data for subsequent temperature calculations and interpolation processing. Accurately recording these coordinate values ​​is crucial for the smooth progress of subsequent steps. The normal vector is an important parameter that describes the local direction of the surface. It is of great significance for calculating heat transfer processes such as solar radiation intensity. By calculating the normal vector of each mesh vertex, the interaction process between solar radiation and the metal roof can be more accurately simulated. The results of the discretization processing are output in a structured form to facilitate subsequent temperature calculations and interpolation processing. The output geometric parameters include three-dimensional spatial coordinates and normal vectors. This information will be directly used in subsequent temperature calculations.

[0070] It should be noted that the normal vector of each mesh vertex is calculated based on the three-dimensional space coordinates of each mesh vertex, specifically including:

[0071] For each vertex in the mesh, we first need to determine all polygonal patches adjacent to that vertex that share that vertex as one of their corner points;

[0072] For each adjacent face, use its vertex coordinates to calculate the normal vector of the face. For a triangular face, the normal vector can be obtained by the vector cross product of the two edges.

[0073] Now that we have the normal vectors for each adjacent face, we can combine them in some way to get the normal vector for the vertex. The most common way is to take the average or weighted average of these face normal vectors. The average is simply calculated by adding the normal vectors of all adjacent faces and then dividing by the number of adjacent faces.

[0074] Preferably, the calculating the relative position relationship between the discrete point and the sun according to the geographical location, season, time and geometric parameters of the discrete point itself specifically includes:

[0075] Acquire basic data of discrete points, wherein the basic data includes geographical location, time information, season information and geometric parameters of the discrete points;

[0076] Calculating the relative position relationship between the discrete points and the sun based on the basic data of the discrete points, wherein the position of the sun includes the solar declination angle, solar hour angle, solar altitude angle and azimuth angle;

[0077] Obtaining the structural surface azimuth;

[0078] The solar incidence angle is calculated based on the basic data of the discrete points and the relative position relationship between the discrete points and the sun.

[0079] In this embodiment, the geographical location (such as longitude and latitude), time information (such as year, month, day, hour, minute), season information and geometric parameters (such as the three-dimensional spatial coordinates and normal vectors of the grid vertices) of the discrete points are accurately obtained. The accuracy of these basic data directly affects the accuracy of subsequent calculations. Through astronomical algorithms, the sun's declination angle, hour angle, altitude angle and azimuth at the current moment can be calculated based on the geographical location, time information and season information of the discrete points. These parameters describe the specific position of the sun in the sky and are the key to the subsequent calculation of the solar incident angle. The azimuth of the structural surface refers to the angle between the ground projection line of the normal of the metal roof or a point on it and the south direction. This parameter is crucial for determining the relative position relationship between sunlight and the metal roof; the solar incident angle is the angle between sunlight and the normal of the metal roof surface. By combining the basic data of discrete points, the position of the sun and the azimuth of the structural surface, the solar incident angle at each discrete point can be calculated. This angle directly affects the distribution and intensity of solar radiation on the metal roof; the solar incident angle not only reflects the relative position relationship between sunlight and the metal roof, but also determines the distribution pattern and intensity of solar radiation on the metal roof. By calculating the solar incident angle, the impact of solar radiation on the temperature of the metal roof can be further analyzed, providing an important basis for subsequent temperature calculations.

[0080] It should be noted that by accurately calculating the position of the sun and the solar incidence angle, the interaction process between solar radiation and metal roofs can be simulated more accurately, thereby improving the accuracy of temperature calculations. This technical solution can be applied to discrete points in different geographical locations, seasons and times, and has strong adaptability and flexibility. By determining the relative position relationship between discrete points and the sun, the impact of solar radiation on the temperature of metal roofs can be further analyzed, providing strong support for building thermal management, energy-saving design and other aspects.

[0081] Preferably, the step of calculating the radiation intensity of the sun to the discrete points based on the relative position relationship between the discrete points and the sun specifically includes:

[0082] According to the relative position relationship between the discrete point and the sun, the direct solar radiation intensity of the discrete point is calculated;

[0083] According to the direct solar radiation intensity at discrete points, the solar scattering intensity at discrete points is calculated;

[0084] According to the direct solar radiation intensity and solar scattering intensity, the surface reflection intensity of discrete points is calculated;

[0085] The solar radiation intensity at discrete points is calculated based on the solar direct radiation intensity, solar scattering intensity and surface reflection intensity.

[0086] In this embodiment, the calculation of the direct solar radiation intensity of the discrete point is based on the relative position relationship between the discrete point and the sun (such as the solar incidence angle). The direct solar radiation intensity refers to the radiation energy directly irradiated by the sun's rays onto the discrete point. The direct solar radiation intensity received by the discrete point at a specific time, place and sun position can be calculated through relevant formulas in astronomy and meteorology. The scattered solar radiation refers to the radiation energy of the sun's rays that reaches the ground after being scattered in the atmosphere. The intensity of this part of the radiation is related to factors such as atmospheric conditions, sun position and ground reflection. When calculating the scattered solar intensity of the discrete point, the influence of factors such as atmospheric transparency, cloud cover and aerosol content on the scattered radiation is usually considered. Based on the direct solar radiation intensity and atmospheric conditions at discrete points, the solar scattering intensity at discrete points can be estimated; surface reflection intensity refers to the ability of the ground (including metal roof) to reflect solar radiation. The intensity of this part of radiation depends on factors such as the material, color, roughness of the ground, and the angle of incidence of the sun. When calculating the surface reflection intensity, it is necessary to know the reflectivity of the ground (also called albedo) and the intensity of direct solar radiation and scattered radiation. By combining these factors, the surface reflection intensity at discrete points can be calculated; the direct solar radiation intensity, solar scattering intensity, and surface reflection intensity are added together to obtain the total radiation intensity of the sun at discrete points. This total radiation intensity is one of the main factors driving the temperature change of the metal roof.

[0087] It should be noted that by separately calculating the solar direct radiation intensity, scattered intensity and surface reflection intensity and adding them together to obtain the total radiation intensity, the impact of solar radiation on the metal roof can be simulated more accurately. This method takes into account the combined effect of multiple factors and improves the accuracy of radiation intensity calculation. Accurate radiation intensity calculation is the basis for subsequent temperature calculation. By obtaining the solar radiation intensity at discrete points, the temperature distribution and change law of the metal roof can be further analyzed, providing strong support for building thermal management, energy-saving design and other aspects.

[0088] The incident angle of sunlight will change at different locations, seasons and times, and as the inclination of the structural surface changes, the incident angle of the sun will also change. The calculation formula is:

[0089] ;

[0090] in, b is the solar altitude angle, which indicates the angle between the incident sun light and the ground. is the solar azimuth, which indicates the angle between the ground projection of the sun's rays and the south direction. g is the structural surface azimuth, which represents the angle between the ground projection line of the structural surface normal and the south direction. a is the angle between the structural surface and the ground, q is the angle between the normal of the incident surface and the sunlight;

[0091] The calculation of solar altitude angle and solar azimuth angle is as follows:

[0092] ;

[0093] ;

[0094] in, ϕ is the geographic latitude, with north latitude as positive. oh is the solar hour angle, d is the solar declination angle;

[0095] The formula for calculating the solar hour angle is:

[0096] ;

[0097] in, t True solar time. Since all parts of China use Beijing time, it is necessary to correct Beijing time. The calculation formula for true solar time is:

[0098] ;

[0099] in, Beijing time, is the time difference, and the calculation formula is as follows:

[0100] ;

[0101] The calculation formula for the solar declination angle is as follows:

[0102] ;

[0103] in, N The ordinal number of the year starting from January 1

[0104] In addition, the steps for calculating direct solar radiation are as follows:

[0105] The radiation projected by the sun onto the atmosphere is close to a constant, but under the influence of the earth's revolution, the distance between the sun and the earth will change. Considering the influence of the change in the distance between the sun and the earth, the solar radiation received by the upper interface of the atmosphere is:

[0106] ;

[0107] in, is the solar constant, take 1367 , N is the ordinal number of the year starting from January 1;

[0108] When sunlight passes through the atmosphere, it will be attenuated to a certain extent by factors such as water vapor, dust, aerosols and ozone in the air. The atmospheric optical quality is corrected to characterize the degree of attenuation of sunlight by the atmosphere. The corrected direct solar radiation is:

[0109] ;

[0110] in, m To take into account the atmospheric optical quality after atmospheric pressure correction, m = / sin(b), b is the solar altitude angle, is the relative air pressure at different altitudes, is the Link's turbidity coefficient;

[0111] The amount of direct sunlight radiation received by the structural surface is related to the inclination angle of the structural surface. For a structural surface with a solar incident angle of q, its direct radiation is:

[0112] .

[0113] The solar scattering calculation steps are as follows:

[0114] The energy scattered by the sky comes from the sunlight itself, so the scattering strength depends on the intensity of direct solar radiation. At the same time, the inclination of the structural surface also has an important influence on the scattering intensity received by the structural surface itself. After considering the view factor correction, the scattering intensity received by the structural surface is:

[0115] ;

[0116] in, is the view factor of the structure facing the sky, =(1+ thing ) / 2, a It is the angle between the structural surface and the ground.

[0117] The steps for calculating surface reflectance are as follows:

[0118] After solar radiation is projected onto the ground, part of the radiation will be reflected by the ground and act on the surface of the structure again. The factors affecting this process are mainly the intensity of the solar radiation itself and the inclination of the structure surface. After considering the angular coefficient correction of the structure surface, the ground reflected radiation intensity received by the structure is:

[0119] ;

[0120] in, is the angular coefficient of the surface to the ground, =(1-cosa) / 2, r is the shortwave reflectivity of the surface.

[0121] The radiation emitted by the sun acts directly or indirectly on the surface of the structure, which can be divided into direct solar radiation, sky scattering and surface reflection:

[0122] ;

[0123] in, G is the total intensity of shortwave radiation, is the direct solar radiation intensity, is the sky scattering intensity, is the surface reflection intensity;

[0124] When short-wave radiation acts on the surface of a structure, it is not completely absorbed by the structure. The ability to absorb solar radiation is an inherent property of the material itself. Under the action of short-wave radiation, the heat flux density generated on the surface of the structure is:

[0125] ;

[0126] in, is the solar radiation absorption coefficient, and the material involved in this article is steel Take 0.7.

[0127] Preferably, the calculation of the heat flux density of thermal convection between the discrete point and the environment specifically includes:

[0128] Get discrete point temperature, ambient temperature and wind speed;

[0129] The convective heat transfer coefficient is calculated based on the wind speed and the geometric shape of the surface at the discrete points;

[0130] The convection heat flux density is calculated based on the discrete point temperature, ambient temperature and convection heat transfer coefficient.

[0131] In this embodiment, the temperature of the discrete point reflects the current thermal state of the discrete point, the ambient temperature represents the thermal state of the surrounding environment, and the wind speed is an important physical quantity that determines the speed and intensity of air flow, thereby affecting the effect of thermal convection. The convective heat transfer coefficient is a key parameter that represents the amount of heat transferred by thermal convection per unit area and unit temperature difference. This coefficient is closely related to the wind speed and the geometric shape of the surface of the discrete point. The greater the wind speed, the faster the air flow and the better the convective heat transfer effect. The geometric shape of the surface of the discrete point (such as roughness, shape factor, etc.) will also affect the effect of convective heat transfer. Through a reasonable mathematical model and experimental data, the convective heat transfer coefficient under a given wind speed and surface geometry can be calculated. After obtaining the discrete point temperature, ambient temperature and convective heat transfer coefficient, the basic formula of thermal convection (such as Newton's cooling law) can be used to calculate the thermal convection heat flux density. This density represents the amount of heat transferred by thermal convection per unit time and per unit area, and is an important indicator for evaluating the intensity of heat exchange between the discrete point and the environment.

[0132] It should be noted that by comprehensively considering multiple factors such as wind speed, surface geometry of discrete points, and temperature difference, the heat flux density of thermal convection can be calculated more accurately. This accuracy is of great significance for subsequent temperature field analysis and thermal management design. Accurate calculation of heat flux density of thermal convection provides an important basis for formulating effective thermal management strategies. For example, in the thermal management of metal roofs, the ventilation design can be optimized and the use of thermal insulation materials can be adjusted according to the calculation results of heat flux density of thermal convection, so as to achieve better energy-saving effects.

[0133] In addition, due to the flow of air, the structure is constantly exchanging heat with the outside world. This process conforms to the mathematical model of Newton's cooling law. The heat flux density on the surface of the structure caused by convection heat transfer can be expressed as:

[0134] ;

[0135] in, is the convective heat transfer coefficient, T is the surface temperature of the structure, The temperature of the outside air.

[0136] As the ambient temperature is in the process of changing, The daily maximum and minimum temperatures and the times they occur can be determined using a trigonometric model:

[0137] ;

[0138] in, =( + ) / 2 is the average of the daily maximum and minimum temperatures, =( - ) / 2 is the daily maximum and minimum temperature variation range, Parameters that affect the time when the maximum and minimum temperatures occur.

[0139] The thermal convection between the structure and the environment is affected by many factors such as wind speed and structural surface roughness. Among them, wind speed has the greatest impact on thermal convection. Considering only the influence of the main factor wind speed, the thermal convection coefficient is calculated according to the following formula:

[0140] .

[0141] Preferably, the calculation of the long-wave radiation heat flux density caused by the long-wave radiation from the ground and the sky specifically includes:

[0142] Get ground temperature, sky temperature, ground emissivity and sky emissivity;

[0143] Calculate the ground radiation power density based on the ground temperature and ground emissivity;

[0144] Calculate the sky radiation power density based on the sky temperature and sky emissivity;

[0145] The long-wave radiation heat flux density is calculated based on the ground radiation power density and the sky radiation power density.

[0146] In this embodiment, the ground temperature and the sky temperature represent the thermal states of the ground and the atmosphere, respectively, while the ground emissivity and the sky emissivity describe their abilities to emit long-wave radiation. The accuracy of these parameters directly affects the accuracy of subsequent calculations. The ground radiation power density refers to the long-wave radiation power emitted by the ground per unit area. The ground radiation power density at a given ground temperature can be calculated through the Stefan-Boltzmann law (or similar radiation laws) and the ground emissivity. This step is the key to evaluating the impact of ground long-wave radiation on the thermal state of discrete points. Similar to the calculation of the ground radiation power density, the sky radiation power density refers to the long-wave radiation power emitted by the sky per unit area. Since the temperature and emissivity of the sky may vary with time and location, this step requires accurate acquisition of the values ​​of these parameters. By calculating the sky radiation power density, the contribution of the sky long-wave radiation to the thermal state of the discrete point can be evaluated; the long-wave radiation heat flux density refers to the heat flux density through the surface of the discrete point caused by the long-wave radiation of the ground and the sky. This density includes both the heating effect of the ground radiation on the discrete point and the cooling effect of the sky radiation on the discrete point (if the sky temperature is lower than the discrete point temperature). The long-wave radiation heat flux density can be calculated by comprehensively considering the ground and sky radiation power densities and their relative positional relationship with the surface of the discrete point (such as angle, distance, etc.).

[0147] It should be noted that by calculating the long-wave radiation power density of the ground and the sky separately and combining them to calculate the long-wave radiation heat flux density, the impact of long-wave radiation on the thermal state of discrete points can be evaluated more accurately. This accuracy is of great significance for understanding the role of thermal radiation in the heat exchange process.

[0148] In addition, while the structure emits thermal radiation to the surrounding environment, it is also radiated by the surrounding environment. This part is called long-wave radiation. According to the Stefan-Boltzmann law, the heat flux density of the structural surface caused by long-wave radiation from the ground and the sky is:

[0149]

[0150] ;

[0151] in, is the surface temperature, taking the surface temperature equal to the atmospheric temperature, is the atmospheric temperature, is the ground radiation emissivity, is the sky radiation emissivity. In this paper, the surface emissivity is taken as 0.9 and the sky radiation emissivity is taken as 0.8. is the Stefan-Boltzmann constant, which is 5.67×10-8W / (m2.K4).

[0152] Preferably, obtaining the temperature value of each discrete point according to the radiation intensity, thermal convection heat flux density and long-wave radiation heat flux density of the discrete point specifically includes:

[0153] The mathematical model of the thermal equilibrium state of discrete points is established by incorporating the radiation intensity, thermal convection heat flux density and long-wave radiation heat flux density of discrete points into the thermal equilibrium equation.

[0154] Solve the mathematical model to obtain the temperature value of each discrete point.

[0155] In this embodiment, by incorporating radiation intensity, heat convection heat flux density and long-wave radiation heat flux density into the heat balance equation, a mathematical model describing the thermal equilibrium state of discrete points can be established. This model takes into account all important heat exchange modes between discrete points and the environment, including radiation, convection and long-wave radiation, and can therefore more accurately reflect the thermal state of discrete points. After the mathematical model is established, the next step is to solve the model to obtain the temperature value of each discrete point, which usually involves numerical calculations or analytical solutions. Depending on the complexity of the model and the availability of computing resources, a suitable solution method can be selected. The solution results will provide the temperature distribution of discrete points at different times and under different environmental conditions, providing an important basis for subsequent thermal management, energy-saving design, etc.

[0156] It should be noted that by comprehensively considering various heat exchange modes and incorporating them into the heat balance equation for modeling and solving, the accuracy of discrete point temperature calculation can be significantly improved. This accuracy is of great significance for understanding the thermal behavior of discrete points and evaluating the effectiveness of thermal management strategies. Accurate temperature calculation results provide an important basis for formulating and optimizing thermal management strategies. For example, in building design, the selection of insulation materials can be optimized and the ventilation design can be adjusted according to the temperature distribution of discrete points.

[0157] In addition, the outer surface of the steel structure is directly exposed to the short-wave radiation of the sun, the long-wave radiation of the environment and the heat convection of the surrounding air. Therefore, the heat flux density at any discrete point on the decorative surface conforms to the following relationship:

[0158] ;

[0159] in, is the thermal conductivity of the material, n is the normal direction of the discrete point on the structural decorative surface. The formula is a quartic equation. By solving the formula, the temperature of the discrete point can be obtained.

[0160] Preferably, the temperature values ​​of all discrete points are combined through interpolation processing to obtain the temperature field distribution of the special-shaped metal roof, which specifically includes:

[0161] Identify and handle outliers in the temperature values ​​of all discrete points;

[0162] The entire data set is interpolated according to the Kriging interpolation method to generate a continuous temperature field;

[0163] The continuous temperature field data is visualized as a temperature field graph to show the temperature distribution of the special-shaped metal roof.

[0164] In this embodiment, in the actual measurement or calculation process, due to the influence of various factors (such as instrument errors, environmental mutations, etc.), outliers may appear in the temperature values ​​of discrete points. If these outliers are not processed, they will have an adverse effect on the subsequent interpolation results. Therefore, before the interpolation process, it is necessary to first identify and process these outliers, which can usually be achieved through statistical methods (such as mean, standard deviation, etc.) or judgment based on physical laws. Methods for processing outliers include deletion, replacement or correction. The Kriging interpolation method is a spatial interpolation technology based on statistics. It takes into account the autocorrelation and variability of spatial data and can generate a smooth and continuous temperature field. This method calculates the spatial relationship between discrete points (such as distance, direction, etc.). etc.), and combined with the variation function to describe this relationship, so as to realize the prediction of the temperature of the unknown area. In the temperature field distribution of the special-shaped metal roof, the Kriging interpolation method can effectively fill the blank areas between discrete points and generate a continuous and accurate temperature field; visualization is the process of converting complex data into intuitive graphics, which helps people understand and analyze data faster. After obtaining continuous temperature field data, it can be converted into a temperature field map through visualization technology (such as drawing software, GIS system, etc.). This map can clearly show the temperature distribution of the special-shaped metal roof, including high temperature areas, low temperature areas and temperature gradients. Through the temperature field map, people can intuitively understand the thermal performance of the metal roof and provide guidance for subsequent improvements and optimizations.

[0165] A computing device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned method for detecting the temperature field distribution of a special-shaped metal roof are implemented.

[0166] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for detecting the temperature field distribution of a special-shaped metal roof.

[0167] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting temperature field distribution of a special-shaped metal roof, characterized in that: Specifically include: Discretize the special-shaped metal roof, use square grid or triangle grid to cut the continuous metal roof surface into equidistant three-dimensional space points, and obtain the geometric parameters of each discrete point; Calculate the relative position relationship between the discrete point and the sun according to the geographical location, season, time and geometric parameters of the discrete point itself; According to the relative position relationship between the discrete point and the sun, calculate the radiation intensity of the sun to the discrete point; Calculate the heat flux density of thermal convection between discrete points and the environment; Calculate the longwave radiation heat flux density caused by the longwave radiation from the ground and the sky; According to the radiation intensity, heat convection heat flux density and long-wave radiation heat flux density of the discrete points, the temperature value of each discrete point is obtained; Through interpolation processing, the temperature values ​​of all discrete points are combined to obtain the temperature field distribution of the special-shaped metal roof; The process of discretizing the special-shaped metal roof is to cut the continuous metal roof surface into equidistant three-dimensional space points using a square grid or a triangular grid, and obtain the geometric parameters of each discrete point, which specifically include: Determine the size of the grid unit based on the boundary shape and size of the metal roof; Get the surface geometry information of the metal roof; According to the surface geometry information of the metal roof and the size requirements of the mesh unit, the CAD software is used to automatically generate the mesh; After the mesh is generated, the three-dimensional space coordinates of each mesh vertex are recorded; According to the three-dimensional space coordinates of each mesh vertex, the normal vector of each mesh vertex is calculated; Output the three-dimensional space coordinates and normal vector of each mesh vertex to obtain the geometric parameters of each discrete point; The calculation of the relative position relationship between the discrete point and the sun according to the geographical location, season, time and geometric parameters of the discrete point itself specifically includes: Acquire basic data of discrete points, wherein the basic data includes geographical location, time information, season information and geometric parameters of the discrete points; Calculating the relative position relationship between the discrete points and the sun based on the basic data of the discrete points, wherein the position of the sun includes the solar declination angle, solar hour angle, solar altitude angle and azimuth angle; Obtaining the structural surface azimuth; The solar incidence angle is calculated based on the basic data of the discrete points and the relative position relationship between the discrete points and the sun.

2. A method for detecting temperature field distribution of a special-shaped metal roof according to claim 1, characterized in that: The step of calculating the radiation intensity of the sun to the discrete point based on the relative position relationship between the discrete point and the sun specifically includes: According to the relative position relationship between the discrete point and the sun, the direct solar radiation intensity of the discrete point is calculated; According to the direct solar radiation intensity at discrete points, the solar scattering intensity at discrete points is calculated; According to the direct solar radiation intensity and solar scattering intensity, the surface reflection intensity of discrete points is calculated; The solar radiation intensity at discrete points is calculated based on the solar direct radiation intensity, solar scattering intensity and surface reflection intensity.

3. A method for detecting temperature field distribution of a special-shaped metal roof according to claim 2, characterized in that: The calculation of the heat flux density of thermal convection between the discrete point and the environment specifically includes: Get discrete point temperature, ambient temperature and wind speed; The convective heat transfer coefficient is calculated based on the wind speed and the geometric shape of the surface at the discrete points; The convection heat flux density is calculated based on the discrete point temperature, ambient temperature and convection heat transfer coefficient.

4. A method for detecting temperature field distribution of a special-shaped metal roof according to claim 3, characterized in that: The calculation of the long-wave radiation heat flux density caused by the long-wave radiation from the ground and the sky specifically includes: Get ground temperature, sky temperature, ground emissivity and sky emissivity; Calculate the ground radiation power density based on the ground temperature and ground emissivity; Calculate the sky radiation power density based on the sky temperature and sky emissivity; The long-wave radiation heat flux density is calculated based on the ground radiation power density and the sky radiation power density.

5. A method for detecting temperature field distribution of a special-shaped metal roof according to claim 4, characterized in that: The temperature value of each discrete point is obtained according to the radiation intensity, heat convection heat flux density and long-wave radiation heat flux density of the discrete point, specifically including: The mathematical model of the thermal equilibrium state of discrete points is established by incorporating the radiation intensity, thermal convection heat flux density and long-wave radiation heat flux density of discrete points into the thermal equilibrium equation. Solve the mathematical model to obtain the temperature value of each discrete point.

6. A method for detecting temperature field distribution of a special-shaped metal roof according to claim 5, characterized in that: The temperature values ​​of all discrete points are combined through interpolation processing to obtain the temperature field distribution of the special-shaped metal roof, which specifically includes: Identify and handle outliers in the temperature values ​​of all discrete points; The entire data set is interpolated according to the Kriging interpolation method to generate a continuous temperature field; The continuous temperature field data is visualized as a temperature field graph to show the temperature distribution of the special-shaped metal roof.

7. A computing device, characterized in that The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method implements the steps of the temperature field distribution detection method of the special-shaped metal roof as claimed in any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the temperature field distribution detection method of the special-shaped metal roof described in any one of claims 1 to 6 are implemented.

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