Thermal bridge simulation calculation method and system of building structure and storage medium

Abstract

According to the thermal bridge simulation calculation method and system for the building structure, a finite difference method is utilized, a complex modeling process is transferred to an Excel tool, thermal bridge calculation is more convenient, fine, complex and professional modeling simulation operation is omitted, a large number of preset numerical values in the Excel tool are utilized, only a small number of parameters need to be input, and the calculation efficiency is improved. Compared with existing CFD fluid mechanics simulation software and THERM software, the method has the advantages that the operation mode is simpler, the calculation accuracy is higher, manual calculation quantization is simplified to the minimum, the measurement and calculation efficiency is improved, the overall heat flow process and temperature distribution of the heat bridge can be conveniently and rapidly calculated, heat bridge analysis of various building construction nodes and materials is supported, and the method is suitable for large-scale popularization and application. And energy conservation and emission reduction design and transformation of various buildings are facilitated.

Description

Technical Field

[0001] The present invention relates to the field of building detection, and in particular to a thermal bridge simulation and measurement method and system for a building structure. Background Art

[0002] A thermal bridge is a location in a building envelope where the thermal resistance differs significantly from the rest of the building envelope due to full or partial penetration by a material with a different heat transfer coefficient than the main envelope, / or local variations in the thickness of the exterior surface, and / or differences in the interior and exterior surface areas of the envelope. A thermal bridge is a weak point in the building structure where heat transfer is concentrated, such as at wall corners or metal connectors. Calculating the heat flow transfer through thermal bridges is a crucial foundation for assessing the thermal bridge effect and is crucial for constructing ultra-low energy buildings.

[0003] Traditional thermal bridge simulation relies on complex three-dimensional simulation software, which is time-consuming and has a high threshold for operation. At present, there is no software in China that can simulate and analyze node thermal bridges separately. It is often calculated by integrating multiple energy consumption analysis software simultaneously. The calculation process adopts the overall area average heat transfer method, which lacks accurate evaluation of thermal bridge details. Currently, CFD fluid model analysis method is widely used, but its usage threshold is high. It can only measure the heat transfer of nodes, and then perform special calculations on the heat transfer of thermal bridges to obtain accurate overall heat transfer heat flow values of thermal bridges. The process is tedious and complicated and requires professional handling. For details, please refer to Figure 1 Taking the outer corner (i.e., the intersection of the same material) as an example, the two-dimensional line thermal bridge algorithm is: the overall two-dimensional thermal coupling heat transfer × the outer length of the outer corner - the sum of the heat transfer of the two sections × the outer length of each section, that is, ψ = U therm ×L therm -(U1×L1+U2×L2), where U therm is the overall two-dimensional thermal coupling heat transfer, L therm is the outer length of the positive angle, U1 and U2 are the heat transfer of the outer sides of the two ends, L1 and L2 are the lengths of the outer sides of the two ends, and L therm =L1+L2. See also Figure 2 The existing thermal bridge measurement process mainly includes two steps: modeling and calculation. During the modeling process, each new model requires resetting boundary conditions such as insulation, thermal conductivity, boundary temperature, and convective thermal conductivity. Considering the high modeling accuracy requirements, but the low accuracy of the model modification tools provided by the software, and the high frequency of errors in simulated devices, it is necessary to draw the thermal bridge geometry. The thermal performance parameters of each layer of material are manually set and assigned to the geometry. In the calculation process, the single-sided heat transfer coefficients U1 and U2 of the material are calculated based on the thermal resistance or thermal conductivity and thickness of each layer of material. The single-sided lengths L1 and L2 of the material are calculated. The simulation result data is substituted into the above formula to calculate the overall heat transfer heat flux value of the two-dimensional line thermal bridge.

[0004] The above overall two-dimensional thermal coupling heat transfer U therm This requires heat transfer calculations using CFD fluid dynamics simulation software, but the operation of such software is extremely complex. Furthermore, the relatively easy-to-use THERM software is unstable and prone to errors, making it inaccurate for thermal bridge calculations. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and system for simulating and calculating thermal bridges in building structures. By using the finite difference method, the complex modeling process is transferred to the Excel tool, making thermal bridge measurement much simpler and eliminating the need for sophisticated, complex and professional modeling and simulation operations. By using a large number of preset values in the Excel tool, only a small number of parameters need to be input. Compared with existing CFD fluid mechanics simulation software and THERM software, the method has a simpler operation mode and higher calculation accuracy, which minimizes manual calculation quantization, improves measurement efficiency, and facilitates the rapid calculation of the overall heat flow process and temperature distribution of the thermal bridge. It supports thermal bridge analysis of various building structural nodes and materials, and contributes to the energy-saving and emission-reduction design and renovation of various types of buildings.

[0006] The present invention is achieved through the following technical solutions:

[0007] A thermal bridge simulation and measurement method for a building structure, comprising:

[0008] Divide the thermal bridge of the building structure into a uniform square grid; wherein each grid node in the square grid represents a temperature calculation point;

[0009] Establishing heat balance equations for all grid nodes in the square grid respectively;

[0010] All heat balance equations are combined to form a linear system of equations;

[0011] The overall heat transfer heat flux value of the thermal bridge is obtained through iterative calculation of Excel macro.

[0012] Optionally, divide the thermal bridges of the building structure into a uniform square grid consisting of:

[0013] Assume that the heat transfer in the thermal bridge area is in a stable state; wherein the stable state means that the heat flowing into any sub-area in the thermal bridge area is equal to the heat flowing out;

[0014] According to the two-dimensional cross-sectional shape and size of the thermal bridge of the building structure, the two-dimensional cross-sectional area of the thermal bridge is divided into uniform square grids.

[0015] Optionally, a heat balance equation is established for each grid node in the square grid, including:

[0016] Each grid node in the square grid is marked as an internal node, a junction node, and a boundary node; wherein the internal node is a node located inside the square grid and contains only one material; the junction node is a node located inside the square grid and contains two materials; and the boundary node is a node located at the outermost edge of the square grid;

[0017] Thermal balance equations are established for the internal nodes, junction nodes and boundary nodes in the square grid respectively.

[0018] Optionally, establishing a heat balance equation for internal nodes within the square grid includes:

[0019] Establishing a heat balance equation for the internal node according to the temperature of the internal node and the temperatures of four nodes adjacent to the internal node;

[0020] A heat balance equation is established for the boundary nodes within the square grid, including:

[0021] Establishing a thermal balance equation for the junction node based on the temperature of the junction node, the temperatures of four nodes adjacent to the junction node, and the thermal conductivity between all materials contained in the junction node;

[0022] A heat balance equation is established for the boundary nodes of the square grid, including:

[0023] A thermal balance equation is established for the boundary node based on the temperature of the boundary node, the temperature of the node adjacent to the boundary node, and preset boundary conditions; wherein the preset boundary conditions include the temperature of the external environment adjacent to the boundary node, a preset recommended temperature, and the convective heat transfer coefficient between the material corresponding to the boundary node and the external environment.

[0024] Optionally, the heat balance equations of all grid nodes are combined to form a linear system of equations, including:

[0025] According to the heat balance equations of all internal nodes, the first steady-state heat transfer differential equation inside the same material is established;

[0026] According to the heat balance equations of all interface nodes, the second steady-state heat transfer differential equation of the interface between different materials is established;

[0027] According to the heat balance equation of the boundary junction node, the third steady-state heat transfer differential equation of the outermost edge of the thermal bridge is established.

[0028] Optionally, the first steady-state heat transfer differential equation is as follows:

[0029]

[0030] In the above formula (1), λ is the thermal conductivity of the material of the internal node, Δx is the transverse dimension of the grid node, Δy is the longitudinal dimension of the grid node, and t i,j is the temperature of the internal node, t i-1,j , t i+1,j , t i,j+1 , t i,j-1 is the temperature of each of the four nodes adjacent to the internal node;

[0031] The second steady-state heat transfer difference equation is as follows:

[0032]

[0033] In the above formula (2), λ1 and λ2 are the thermal conductivity coefficients of the two materials contained in the boundary node, Δx is the transverse dimension of the grid node, Δy is the longitudinal dimension of the grid node, and t i,j is the temperature of the junction node, t i-1,j , t i+1,j , t i,j+1 , t i,j-1 is the temperature of the four adjacent nodes around the junction node;

[0034] The third steady-state heat transfer differential equation is as follows:

[0035]

[0036] In the above formula (3), λ is the thermal conductivity of the material of the boundary node, Δx is the transverse dimension of the grid node, Δy is the longitudinal dimension of the grid node, and t 0,j is the temperature of the boundary node, t 1,j , t 0,j+1 , t 0,j-1 is the temperature of the three nodes adjacent to the boundary node, t f1 is the temperature of the external environment adjacent to the boundary node, and h1 is a preset constant coefficient.

[0037] Optionally, the overall heat transfer heat flux value of the thermal bridge is obtained by iterative calculation using an Excel macro, including:

[0038] Perform iterative calculations on the linear equations using an Excel macro to solve the temperature values of all grid nodes;

[0039] According to the temperature values of all grid nodes, the global temperature distribution and heat flow path of the thermal bridge are obtained, thereby calculating the overall heat transfer heat flow value of the thermal bridge.

[0040] A thermal bridge simulation and measurement system for a building structure, comprising:

[0041] A division module, used to divide the thermal bridge of the building structure into uniform square grids; wherein each grid node in the square grid represents a temperature calculation point;

[0042] an equation building module, for establishing heat balance equations for all grid nodes in the square grid;

[0043] The equation combination module is used to combine all the heat balance equations to form a linear equation system;

[0044] The heat flow calculation module is used to obtain the overall heat transfer heat flow value of the thermal bridge through iterative calculation of Excel macro.

[0045] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method according to any one of claims 1 to 5.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The thermal bridge simulation and measurement method and system for building structures provided in this application utilize the finite difference method to transfer the complex modeling process to the Excel tool, making thermal bridge measurement much simpler and eliminating the need for sophisticated, complex and professional modeling and simulation operations. By utilizing a large number of preset values in the Excel tool, only a small number of parameters need to be input. Compared with existing CFD fluid mechanics simulation software and THERM software, it has a simpler operation mode and higher calculation accuracy, minimizes manual calculation quantification, improves measurement efficiency, and facilitates the rapid calculation of the overall heat flow process and temperature distribution of the thermal bridge. It supports thermal bridge analysis of various building structural nodes and materials, and contributes to the energy-saving and emission-reduction design and renovation of various types of buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. Among them:

[0049] Figure 1 This is the principle diagram for calculating the overall heat transfer heat flux value of a two-dimensional line thermal bridge.

[0050] Figure 2 This is a schematic diagram of the simulation and calculation of the overall heat transfer heat flux value of a two-dimensional line thermal bridge in the existing technology.

[0051] Figure 3A schematic flow chart of a thermal bridge simulation and measurement method for a building structure provided by the present invention.

[0052] Figure 4 Schematic diagram of the internal nodes after dividing the square mesh for thermal bridges.

[0053] Figure 5 Illustration of the preset boundary conditions set for the boundary nodes.

[0054] Figure 6 Schematic diagram of heat transfer at internal nodes.

[0055] Figure 7 Schematic diagram of heat transfer at the junction node.

[0056] Figure 8 Schematic diagram of heat transfer at the boundary nodes.

[0057] Figure 9 This is a structural schematic diagram of a thermal bridge simulation and measurement system for a building structure provided by the present invention.

[0058] Figure 10 This is a diagram of the heat transfer coefficient U1 calculation operation interface for implementing the thermal bridge simulation measurement method of the present invention.

[0059] Figure 11 This is a diagram of the heat transfer coefficient U2 calculation operation interface for implementing the thermal bridge simulation measurement method of the present invention.

[0060] Figure 12 This is a diagram of the operating interface for confirming the outdoor side lengths of transverse and longitudinal components in implementing the thermal bridge simulation and measurement method of the present invention.

[0061] Figure 13 This is an operation interface diagram for setting boundary conditions for implementing the thermal bridge simulation and measurement method of the present invention.

[0062] Figure 14 This is a diagram of the operating interface for setting the iterative calculation step size of the thermal bridge simulation measurement method implemented in the present invention.

[0063] Figure 15 This is a temperature cloud diagram obtained by iterative calculation of the thermal bridge simulation measurement method implemented in the present invention.

[0064] Figure 16 This is an interface diagram of the two-dimensional thermal bridge value calculation process of the thermal bridge simulation measurement method implemented in the present invention.

[0065] Figure 17 This is a tool interface diagram for implementing the thermal bridge simulation and measurement method of the present invention.

[0066] Figure 18 This is a diagram of the measurement interface for implementing the thermal bridge simulation measurement method of the present invention. DETAILED DESCRIPTION

[0067] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0068] As used herein, the terms "comprise," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0069] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0070] See also Figure 3 As shown, an embodiment of the present application provides a method for simulating and calculating thermal bridges in a building structure. The method for simulating and calculating thermal bridges in a building structure includes:

[0071] Divide the thermal bridge of the building structure into a uniform square grid; each grid node in the square grid represents a temperature calculation point;

[0072] Establish heat balance equations for all grid nodes in the square grid;

[0073] All heat balance equations are combined to form a linear system of equations;

[0074] The overall heat transfer heat flux value of the thermal bridge is obtained through iterative calculation of Excel macro.

[0075] The beneficial effects of the above embodiments are that the thermal bridge simulation and measurement method of the building structure utilizes the finite difference method to transfer the complex modeling process to the Excel tool, making the thermal bridge measurement much simpler and eliminating the need for sophisticated, complex and professional modeling and simulation operations. By utilizing a large number of preset values in the Excel tool, only a small number of parameters need to be input. Compared with the existing CFD fluid mechanics simulation software and THERM software, it has a simpler operation mode and higher calculation accuracy, which minimizes manual calculation quantification, improves measurement efficiency, and facilitates the rapid calculation of the overall heat flow process and temperature distribution of the thermal bridge. It supports thermal bridge analysis of various building structural nodes and materials, and is helpful for energy-saving and emission reduction design and renovation of various types of buildings.

[0076] In another embodiment, the thermal bridges of the building structure are divided into a uniform square grid, comprising:

[0077] Assume that the heat transfer in the thermal bridge area is in a steady state. A steady state means that the heat flowing into any sub-area in the thermal bridge area is equal to the heat flowing out.

[0078] According to the two-dimensional cross-sectional shape and size of the thermal bridge of the building structure, the two-dimensional cross-sectional area of the thermal bridge is divided into uniform square grids.

[0079] To simplify the heat conduction problem of building thermal bridges, we assume that the building thermal bridges have two-dimensional steady-state thermal conductivity characteristics. This assumes that the heat transfer in the thermal bridge region is stable, meaning that the temperature in the thermal bridge region does not change over time and the temperature distribution is uniform across the thickness. This simplifies the heat transfer in the thermal bridge region to a two-dimensional planar problem. In this case, heat transfer in the thermal bridge region follows the "inflow and outflow balance" principle, meaning that the heat flowing into any subregion within the thermal bridge region is equal to the heat flowing out. This simplifies the analysis of heat transfer in the thermal bridge region.

[0080] Alternatively, the 2D cross-section of the thermal bridge of a building structure can be divided into a uniform square grid based on its shape and size. Each grid node within the square grid represents a temperature calculation point. The smaller the grid, the more accurate the calculation result, but the greater the computational effort. Based on the distribution of different grids within the square grid obtained by dividing the thermal bridge of the building structure and the material type corresponding to the grid, the square grid of the thermal bridge includes three types of nodes: internal nodes, junction nodes, and boundary nodes. Internal nodes are nodes located within the square grid and contain only one material; junction nodes are nodes located within the square grid and contain two materials; and boundary nodes are nodes located at the outermost edge of the square grid. See [ 15 ]. Figure 4 , is the shape structure of the internal node, and the horizontal and vertical dimensions of the internal node are Δx and Δy respectively. In addition, the horizontal and vertical dimensions of the junction nodes and boundary nodes are the same as those of the internal nodes, and are not repeated here.

[0081] In another embodiment, heat balance equations are established for all grid nodes in the square grid, including:

[0082] Each grid node in the square grid is calibrated as an internal node, a junction node, and a boundary node; an internal node is a node located inside the square grid and contains only one material; a junction node is a node located inside the square grid and contains two materials; and a boundary node is a node located at the outermost edge of the square grid.

[0083] The heat balance equations are established for the internal nodes, junction nodes and boundary nodes in the square grid.

[0084] In another embodiment, a heat balance equation is established for the internal nodes within the square grid, including:

[0085] According to the temperature of the internal node and the temperatures of the four nodes adjacent to the internal node, a heat balance equation is established for the internal node;

[0086] The heat balance equations are established for the boundary nodes within the square grid, including:

[0087] A thermal balance equation is established for the junction node based on the temperature of the junction node, the temperatures of the four nodes adjacent to the junction node, and the thermal conductivity between all materials contained in the junction node.

[0088] The heat balance equations are established for the boundary nodes of the square mesh, including:

[0089] A thermal balance equation is established for the boundary node based on the temperature of the boundary node, the temperature of the node adjacent to the boundary node, and the preset boundary conditions; wherein the preset boundary conditions include the temperature of the external environment adjacent to the boundary node, the preset recommended temperature, and the convective heat transfer coefficient between the material corresponding to the boundary node and the external environment.

[0090] An internal node is located within a square grid, and the four adjacent nodes surrounding it are made of the same material. The temperature of each internal node is determined by the four adjacent nodes above, below, and to the left and right of it. According to the law of conservation of energy, the total heat flowing into an internal node equals the total heat flowing out. This is mathematically converted to a weighted average of the temperatures of the adjacent nodes, which is used to establish a heat balance equation for the internal node.

[0091] For the junction node, it is adjacent to other nodes on all sides. Taking into account the material differences between the junction node and its adjacent nodes, according to the law of conservation of energy, the total heat flowing into the internal node is still equal to the total heat flowing out. According to the difference in thermal conductivity of different materials, the heat flow weight ratio of other adjacent nodes is mathematically adjusted to establish a thermal balance equation for the junction node.

[0092] For the boundary nodes, they are adjacent to the external environment, so that the heat flow of the boundary nodes is directly affected by the temperature of the external environment and the corresponding air convection conditions. Figure 5 As shown, first set the temperature of the external environment adjacent to the boundary node, the preset recommended temperature, and the preset boundary conditions of the convective heat transfer coefficient between the material corresponding to the boundary node and the external environment. Then, according to the temperature of the boundary node, the temperature of the node adjacent to the boundary node, and the preset boundary conditions, establish a thermal balance equation for the boundary node.

[0093] In another embodiment, the heat balance equations of all grid nodes are combined to form a linear equation system, including:

[0094] According to the heat balance equations of all internal nodes, the first steady-state heat transfer differential equation inside the same material is established;

[0095] According to the heat balance equations of all interface nodes, the second steady-state heat transfer differential equation of the interface between different materials is established;

[0096] According to the heat balance equation of the boundary junction nodes, the third steady-state heat transfer differential equation of the outermost edge of the thermal bridge is established.

[0097] In another embodiment, if Figure 6 The figure shows the heat transfer schematic of the internal nodes. The first steady-state heat transfer differential equation is as follows:

[0098]

[0099] In the above formula (1), λ is the thermal conductivity of the material of the internal node, Δx is the lateral size of the grid node, Δy is the longitudinal size of the grid node, and t i,j is the temperature of the internal node, t i-1,j , t i+1,j , t i,j+1 , t i,j-1 is the temperature of the four adjacent nodes around the internal node;

[0100] like Figure 7 The figure shows a schematic diagram of heat transfer at the junction node. The second steady-state heat transfer differential equation is as follows:

[0101]

[0102] In the above formula (2), λ1 and λ2 are the thermal conductivity coefficients of the two materials contained in the boundary node, Δx is the horizontal dimension of the grid node, Δy is the vertical dimension of the grid node, and t i,j is the temperature of the junction node, t i-1,j , t i+1,j , t i,j+1 , t i,j-1is the temperature of the four adjacent nodes around the junction node;

[0103] like Figure 8 The figure shows a schematic diagram of heat transfer at the boundary nodes. The third steady-state heat transfer differential equation is as follows:

[0104]

[0105] In the above formula (3), λ is the thermal conductivity of the material of the boundary node, Δx is the horizontal dimension of the grid node, Δy is the vertical dimension of the grid node, and t 0,j is the temperature of the boundary node, t 1,j , t 0,j+1 , t 0,j-1 is the temperature of the three nodes adjacent to the boundary node, t f1 is the temperature of the external environment adjacent to the boundary node, and h1 is the preset constant coefficient.

[0106] In another embodiment, the overall heat transfer heat flux value of the thermal bridge is obtained by iterative calculation using an Excel macro, including:

[0107] The linear equations are iteratively calculated using Excel macros to obtain the temperature values of all grid nodes;

[0108] According to the temperature values of all grid nodes, the global temperature distribution and heat flow path of the thermal bridge are obtained, and the overall heat transfer heat flow value of the thermal bridge is calculated.

[0109] In actual work, the following algorithm can be set in the Excel macro for iterative calculation to obtain the temperature values of all grid nodes.

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] 'Output the result (e.g. to an Excel cell)

[0116] wsParams.Cells(12,"B").Value=q_left

[0117] wsParams.Cells(13,"B").Value=q_top

[0118] wsParams.Cells(14,"B").Value=q_right

[0119] wsParams.Cells(15,"B").Value=q_bottom

[0120] wsParams.Cells(16,"B").Value=q_total

[0121] wsParams.Cells(17,"B").Value=U

[0122] Exit Sub

[0123] ErrorHandler:

[0124] MsgBox "An error occurred: " & Err.Description, vbExclamation

[0125] End Sub

[0126] Function GetValidK(indexAsLong,k()AsDouble)AsDouble

[0127] Ifindex>=LBound(k)Andindex<=UBound(k)Then

[0128] GetValidK=k(index)

[0129] Else

[0130] GetValidK=0

[0131] Debug.Print"Index out of bounds:index="&index

[0132] EndIf

[0133] EndFunction

[0134] See also Figure 9 As shown, an embodiment of the present application provides a thermal bridge simulation and measurement system for a building structure. The thermal bridge simulation and measurement system for a building structure includes:

[0135] A partitioning module is used to divide the thermal bridge of the building structure into uniform square grids; wherein each grid node in the square grid represents a temperature calculation point;

[0136] Equation building module, used to build heat balance equations for all grid nodes in the square grid;

[0137] The equation combination module is used to combine all the heat balance equations to form a linear equation system;

[0138] The heat flow calculation module is used to obtain the overall heat transfer heat flow value of the thermal bridge through iterative calculation of Excel macros.

[0139] The operation and effects of the thermal bridge simulation and calculation system for building structures of the present invention correspond to and are consistent with those of the above-mentioned thermal bridge simulation and calculation method for building structures, and the thermal bridge simulation and calculation system for building structures will not be repeated here.

[0140] The present invention uses a corner thermal bridge as an example to implement the above thermal bridge simulation and measurement method. The specific process is as follows:

[0141] (1) Figure 10 As shown in the figure, the material composition of the transverse member is set and the corresponding heat transfer coefficient U1 is obtained; specifically, according to the actual material distribution, its thickness, area ratio, thermal conductivity (which can be obtained by looking up the table) is set layer by layer, and the indoor and outdoor boundary conditions are set to obtain the corresponding surface heat transfer thermal resistance;

[0142] (2) Figure 11 As shown in the figure, the material composition of the longitudinal component is set and the corresponding heat transfer coefficient U2 is obtained; specifically, according to the actual material distribution, its thickness, area ratio, thermal conductivity (which can be obtained by looking up the table) is set layer by layer, and the indoor and outdoor boundary conditions are set to obtain the corresponding surface heat transfer thermal resistance;

[0143] (3) Figure 12 As shown, after completing the above steps (1) and (2), the values of the heat transfer coefficients U1 and U2 are automatically obtained, and the outdoor side lengths L1 and L2 of the transverse and longitudinal members are confirmed, where L1 and L2 are not less than 1.2m;

[0144] (4) Figure 13 As shown, to set the boundary conditions, you can select the actual environmental conditions (outside) and airflow direction (inside) of the corresponding position in the "Condition" column, thereby automatically obtaining the corresponding convective heat transfer coefficient and temperature; the boundary conditions can be set according to the official recommended values of PHI;

[0145] (5) Figure 14 As shown, set the iterative calculation step size, preferably set it to more than 1000 steps, and then click the "U_therm Run Calculation" button to calculate the overall heat transfer heat flux value;

[0146] (6) Using the finite difference method, iteratively calculate the component temperature and heat flow transfer. Figure 15 As shown, the temperature cloud chart is displayed in EXCEL with the preset number series corresponding to the material serial number and the number corresponding to the color condition format;

[0147] (7) Figure 16 As shown in the figure, the U_therm value is obtained, and the two-dimensional thermal bridge value is automatically calculated according to the preset formula.

[0148] In addition, the tool interface and calculation interface for implementing the above thermal bridge simulation calculation method are as follows: Figure 17 and 18 shown.

[0149] In one embodiment of the present invention, the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method described above is implemented.

[0150] In one embodiment of the present invention, the present invention further provides a computer device, which includes at least a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the method described above is implemented.

[0151] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by adding a necessary general hardware platform, and of course can also be implemented by a combination of hardware and software. Based on this understanding, the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a computer product. The present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0152] Overall, the proposed thermal bridge simulation and measurement method and system for building structures have the following advantages: It provides a one-stop, efficient, and convenient thermal bridge measurement method, enabling rapid calculation of various types of thermal bridges; it provides a user-friendly interface through the Excel tool, facilitating user operation and data input, while also possessing powerful data processing and analysis capabilities; it ensures the accuracy and reliability of the measurement through extensive testing and verification, providing users with reliable decision-making support; it applies thermal bridge measurement to actual engineering projects, promoting the innovation and application of building energy-saving technologies, and reducing building energy consumption and operating costs; this invention applies finite-difference data simulation technology to thermal bridge measurement for the first time, proposing a method based on the Macro language combined with Excel to speed up thermal bridge analysis and lower the technical barriers for users; it constructs a highly integrated and comprehensive thermal bridge measurement method, providing users with a more convenient and efficient tool; the accuracy of thermal bridge measurement exceeds 95%, and the simulation iteration response time on a standard computer does not exceed 300 seconds. It supports thermal bridge analysis for a variety of building structural nodes and materials, and can be widely used in the design and renovation of various types of buildings, such as residential buildings, office buildings, and industrial plants, helping to achieve energy conservation, emission reduction, and sustainable development goals.

[0153] The above is only a specific embodiment of the present invention, and any other improvements made based on the concept of the present invention are considered to be within the scope of protection of the present invention.

Claims

1. A method for simulating and calculating thermal bridges of building structures, characterized in that: include: Divide the thermal bridge of the building structure into a uniform square grid; wherein each grid node in the square grid represents a temperature calculation point; Establishing heat balance equations for all grid nodes in the square grid respectively; All heat balance equations are combined to form a linear system of equations; The overall heat transfer heat flux value of the thermal bridge is obtained through iterative calculation of Excel macro.

2. The method for simulating and calculating thermal bridges in a building structure according to claim 1, wherein: Divide the building structure's thermal bridges into a uniform square grid consisting of: Assume that the heat transfer in the thermal bridge area is in a stable state; wherein the stable state means that the heat flowing into any sub-area in the thermal bridge area is equal to the heat flowing out; According to the two-dimensional cross-sectional shape and size of the thermal bridge of the building structure, the two-dimensional cross-sectional area of the thermal bridge is divided into uniform square grids.

3. The method for simulating and calculating thermal bridges in a building structure according to claim 1, wherein: A heat balance equation is established for each grid node in the square grid, including: Each grid node in the square grid is calibrated as an internal node, a junction node, and a boundary node; wherein the internal node is a node located inside the square grid and contains only one material; the boundary node is a node located inside the square grid and contains two materials; The boundary nodes are nodes located at the outermost edge of the square grid; Thermal balance equations are established for the internal nodes, junction nodes and boundary nodes in the square grid respectively.

4. The method for simulating and calculating thermal bridges in a building structure according to claim 3, wherein: A heat balance equation is established for the internal nodes within the square grid, including: Establishing a heat balance equation for the internal node according to the temperature of the internal node and the temperatures of four nodes adjacent to the internal node; A heat balance equation is established for the boundary nodes within the square grid, including: Establishing a thermal balance equation for the junction node based on the temperature of the junction node, the temperatures of four nodes adjacent to the junction node, and the thermal conductivity between all materials contained in the junction node; A heat balance equation is established for the boundary nodes of the square grid, including: A thermal balance equation is established for the boundary node based on the temperature of the boundary node, the temperature of the node adjacent to the boundary node, and preset boundary conditions; wherein the preset boundary conditions include the temperature of the external environment adjacent to the boundary node, a preset recommended temperature, and the convective heat transfer coefficient between the material corresponding to the boundary node and the external environment.

5. The method for simulating and calculating thermal bridges in a building structure according to claim 3, wherein: The heat balance equations of all grid nodes are combined to form a linear equation system, including: According to the heat balance equations of all internal nodes, the first steady-state heat transfer differential equation inside the same material is established; According to the heat balance equations of all interface nodes, the second steady-state heat transfer differential equation of the interface between different materials is established; According to the heat balance equation of the boundary junction node, the third steady-state heat transfer differential equation of the outermost edge of the thermal bridge is established.

6. The method for simulating and calculating thermal bridges in a building structure according to claim 5, wherein: The first steady-state heat transfer difference equation is as follows: In the above formula (1), λ is the thermal conductivity of the material of the internal node, Δx is the transverse dimension of the grid node, Δy is the longitudinal dimension of the grid node, and t i,j is the temperature of the internal node, t i-1,j , t i+1,j , t i,j+1 , t i,j-1 is the temperature of each of the four nodes adjacent to the internal node; The second steady-state heat transfer difference equation is as follows: In the above formula (2), λ1 and λ2 are the thermal conductivity coefficients of the two materials contained in the boundary node, Δx is the transverse dimension of the grid node, Δy is the longitudinal dimension of the grid node, and t i,j is the temperature of the junction node, t i-1,j , t i+1,j , t i,j+1 , t i,j-1 is the temperature of the four adjacent nodes around the junction node; The third steady-state heat transfer differential equation is as follows: In the above formula (3), λ is the thermal conductivity of the material of the boundary node, Δx is the transverse dimension of the grid node, Δy is the longitudinal dimension of the grid node, and t 0,j is the temperature of the boundary node, t 1,j , t 0,j+1 , t 0,j-1 is the temperature of the three nodes adjacent to the boundary node, t f1 is the temperature of the external environment adjacent to the boundary node, and h1 is a preset constant coefficient.

7. The method for simulating and calculating thermal bridges in a building structure according to claim 1, wherein: The overall heat transfer heat flux value of the thermal bridge is obtained through iterative calculation of Excel macro, including: Perform iterative calculations on the linear equations using an Excel macro to solve the temperature values of all grid nodes; According to the temperature values of all grid nodes, the global temperature distribution and heat flow path of the thermal bridge are obtained, thereby calculating the overall heat transfer heat flow value of the thermal bridge.

8. A thermal bridge simulation and measurement system for building structures, characterized in that: include: A division module, used to divide the thermal bridge of the building structure into uniform square grids; wherein each grid node in the square grid represents a temperature calculation point; an equation building module, for establishing heat balance equations for all grid nodes in the square grid; The equation combination module is used to combine all the heat balance equations to form a linear equation system; The heat flow calculation module is used to obtain the overall heat transfer heat flow value of the thermal bridge through iterative calculation of Excel macro.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the computer program implements the method according to any one of claims 1 to 7.

Images