A design method and device for a new type of roof additional component for a prefabricated cabin in a substation

Abstract

The present invention discloses a design method and device for a new type of additional roof component for a prefabricated cabin of a substation. The outer contour of the aerodynamic component in the present invention is obtained by numerical simulation of the flow field around the prefabricated cabin substation using computational fluid dynamics. After installing this type of aerodynamic component on the original structure, it scientifically changes the local aerodynamic shape, so that the flow field in the corner area of ​​the prefabricated cabin fits the contour of the component, and suppresses the flow separation and vortex generation in the corner area of ​​the prefabricated cabin. Compared with the situation without such a component, or the simple open parapet structure used in previous studies, it can scientifically suppress the vortex and separation flow in the corner area of ​​the structure, thereby reducing the extreme negative pressure, improving the wind resistance safety of the structure, and having a simple and beautiful structure while meeting the functions.

Description

Technical Field

[0001] The invention relates to the field of construction, and in particular to a design method and a device for a novel roof additional component of a prefabricated cabin of a transformer substation. Background Art

[0002] In the southeastern coastal areas of my country, low-rise buildings represented by double-slope roofs are widely used in some occasions. Under the action of strong winds, such buildings are also prone to wind disaster damage, and their wind resistance cannot be ignored. The results of the on-site investigation of wind disasters show that the damage to low-rise double-slope roof buildings under wind disasters is mainly the damage to the enclosure structure, which is mainly manifested in the damage of vulnerable parts such as the windward roof corners, eaves edges and ridges, or the overall or partial damage of the roof, which leads to the overall collapse of the building.

[0003] Destruction mechanism of low buildings under strong wind:

[0004] When strong wind loads act on the surface of low buildings, the separation, entrainment and reattachment of the incoming flow cause various organized destructive vortices to appear on the building surface. The two most typical destructive vortices are columnar vortices and conical vortices, such as Figure 1 As shown. When the incoming flow is perpendicular to the windward front edge of the building, a strong pulsating suction will be generated near the windward front edge under the action of the columnar vortex; when the incoming flow forms a certain angle with the windward front edge of the building (oblique wind), a series of conical vortices will be generated. Compared with the columnar vortex, the conical vortex is more stable and continuous, and the wind suction under its action is also stronger. Under the action of these two types of vortices, strong suction will first appear in the separation zone near the windward front edge of the roof surface, which will cause damage to the separation zone; then, the damage will spread to most areas of the roof; finally, the roof will be lifted and the entire structure will fail.

[0005] For this type of low-rise building, local adjustments and modifications to the roof shape can change its wind load characteristics. For example, setting up overhanging eaves and permeable parapet structures can reduce the negative pressure near the building eaves and ridges to a certain extent. Although this type of traditional components (overhanging eaves, parapets, etc.) also have a certain effect of reducing the negative pressure in the corners, their appearance has not been scientifically designed in combination with the specific flow characteristics of the building in question, and the effect is limited. For industrial buildings such as prefabricated cabin substations, modifying the eaves design and setting up parapets on their ridges is neither realistic nor aesthetically pleasing. Summary of the invention

[0006] In order to solve at least one technical problem existing in the above-mentioned background technology, the present invention provides a design method and device for a new type of roof additional component of a prefabricated cabin of a substation.

[0007] To achieve the above object, the technical solution of the present invention is:

[0008] In a first aspect, the present invention provides a design method for a novel roof additional component of a prefabricated cabin of a substation, comprising:

[0009] Step 1: Establish a numerical wind tunnel model of the prefabricated cabin building;

[0010] Step 2: Import the calculation result file of the wind direction condition perpendicular to the building facade wall in the numerical wind tunnel model into the CFD post-processing module for flow field visualization. First, select a section perpendicular to the eaves direction near the corner area of ​​the prefabricated cabin roof and display the velocity contour cloud map on the section.

[0011] Step 3: Select a velocity contour line in the velocity contour cloud map as the target streamline; then use the same method to make several parallel velocity contour cloud maps, take the same velocity streamline in each cloud map, and make a series of target streamlines; fit each target streamline with a spline function curve, and then enclose the spline curve to form a 3D surface on one side of the corner area;

[0012] Step 4: Using the above steps 2 and 3, similarly obtain a series of target streamlines on the other side of the roof corner area under another wind direction angle condition perpendicular to the front facade wall of the building, and fit the target streamlines to enclose another 3D surface;

[0013] Step 5: Perform a Boolean addition operation on the two 3D surfaces on both sides of the building roof corner area obtained in Steps 3 and 4 above, and modify their intersection lines appropriately to obtain a complete streamlined 3D surface;

[0014] Step 6: Design holes on the streamlined 3D surface to reduce the wind load on the component itself and meet the drainage function requirements, so as to obtain a final form of an aerodynamic roof additional component.

[0015] Furthermore, the step 1 comprises:

[0016] Step 101: constructing a three-dimensional geometric model of the prefabricated cabin building to obtain a three-dimensional geometric model of the prefabricated cabin building;

[0017] Step 102: Determine the size of the calculation domain of the three-dimensional model of the prefabricated cabin building, and obtain the three-dimensional calculation domain space after deducting the building;

[0018] Step 103: Using a meshing tool to perform mesh discretization on the obtained three-dimensional computational domain space to obtain a mesh model;

[0019] Step 104: Import the divided grid model into computational fluid dynamics (CFD) software to set boundary conditions to perform CFD simulation calculations under different wind direction angles.

[0020] Furthermore, in the step 101, the constructed three-dimensional geometric model of the prefabricated cabin building is constructed as a real-scale model according to the actual size of the prefabricated cabin building design or as a scale model with an appropriate scale ratio.

[0021] Furthermore, the step 102 includes:

[0022] Determine the size of the computational domain. The size of the computational domain should ensure that the maximum blockage ratio of the model along the wind direction is no more than 3%. The upstream inlet, downstream outlet, both sides, and top surface of the computational domain should be no less than 5, 10, 5, and 5 times the characteristic height of the building, respectively. Import the three-dimensional geometric model of the prefabricated cabin building into the computational domain, perform Boolean subtraction operations, and obtain the three-dimensional computational domain space after deducting the building.

[0023] Furthermore, the characteristic building height is the building height of the prefabricated cabin.

[0024] Furthermore, the step 103 includes:

[0025] The cylindrical space of the computational domain surrounding the building is taken as the inner domain, and the area outside the building is taken as the outer domain. A mixed grid division scheme of inner and outer domains is adopted, in which the inner domain of the cylinder wrapping the building adopts an unstructured grid, and the outer domain adopts a structured grid, thus completing the grid discretization of the entire computational domain.

[0026] Furthermore, the step 104 includes:

[0027] First, determine the landform type around the building under study, and use the boundary condition mathematical model that simulates the equilibrium atmospheric boundary layer to define the boundary conditions of the velocity inlet; the inlet adopts the velocity inlet condition, the outlet adopts the pressure outlet condition, the ground and building surface adopt the no-slip wall condition, and the two side surfaces and the top surface adopt the symmetrical boundary; after setting the boundary conditions, selecting the appropriate turbulence model and calculation parameters, carry out CFD simulation calculations under different wind direction angles.

[0028] Furthermore, the suitable turbulence model is the SST k-ω model in the RANS Reynolds average method.

[0029] Furthermore, the design method of the novel roof additional component of the substation prefabricated cabin also includes:

[0030] Step 7: The final form of the obtained roof additional component is printed and produced using 3D printing technology.

[0031] In a second aspect, the present invention provides a design device for a new type of additional roof component for a prefabricated cabin of a substation, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the above methods when executing the computer program.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The outer contour of the aerodynamic component in the present invention is obtained by numerical simulation of the flow field around the prefabricated cabin substation through computational fluid dynamics. After installing this type of aerodynamic component on the original structure, it scientifically changes the local aerodynamic shape, so that the flow field in the corner area of ​​the prefabricated cabin fits the contour of the component, suppressing the flow separation and vortex generation in the corner area of ​​the prefabricated cabin. Compared with the situation without such a component, or the simple open parapet structure used in previous studies, it can scientifically suppress the vortex and separation flow in the corner area of ​​the structure, thereby reducing the extreme negative pressure, improving the wind resistance safety of the structure, and having a simple and beautiful structure while meeting the functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The following is a schematic diagram of two typical destructive vortices, columnar vortex and conical vortex, in wind damage to buildings of this type;

[0035] Figure 2 A flow chart of a design method for a novel roof additional component of a prefabricated cabin of a substation provided by an embodiment of the present invention;

[0036] Figure 3 Flow chart for step 1;

[0037] Figure 4 This is the model diagram of the prefabricated comprehensive cabin of a substation (unit: mm);

[0038] Figure 5 The local grid division diagram of the numerical wind tunnel for the prefabricated cabin substation;

[0039] Figure 6 This is the numerical wind tunnel model diagram of the prefabricated cabin substation;

[0040] Figure 7 It is the velocity contour on a certain cross section;

[0041] Figure 8 is the streamline fitting diagram of the corner area;

[0042] Fig. 9 It is the streamline surface fitting diagram of the corner area;

[0043] Fig.10 It is the trimming diagram of the corner surface;

[0044] Fig.11 is a schematic diagram of the component outline (unit: mm);

[0045] Fig.12 This is a schematic diagram of the finished component;

[0046] Fig.13This is a schematic diagram of the design device composition of the new roof additional component of the substation prefabricated cabin provided in this embodiment 3. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0048] Embodiment 1:

[0049] See also Figure 2 As shown, this embodiment provides a design method for a new type of additional roof component of a substation prefabricated cabin, including:

[0050] Step 1: Based on the principle of computational fluid dynamics (CFD), a numerical wind tunnel model of the prefabricated cabin building is established;

[0051] Step 2: Import the calculation result file of the wind direction condition perpendicular to the building facade wall in the numerical wind tunnel model into the CFD post-processing module for flow field visualization. First, select a section perpendicular to the eaves direction near the corner area of ​​the prefabricated cabin roof and display the velocity contour cloud map on the section.

[0052] Step 3: Select a velocity contour line in the velocity contour cloud map as the target streamline; then use the same method to make several parallel velocity contour cloud maps, take the same velocity streamline in each cloud map, and make a series of target streamlines; fit each target streamline with a spline function curve, and then enclose the spline curve to form a 3D surface on one side of the corner area;

[0053] Step 4: Using the above steps 2 and 3, similarly obtain a series of target streamlines on the other side of the roof corner area under another wind direction angle condition perpendicular to the front facade wall of the building, and fit the target streamlines to enclose another 3D surface;

[0054] Step 5: Perform a Boolean addition operation on the two 3D surfaces on both sides of the building roof corner area obtained in Steps 3 and 4 above, and modify their intersection lines appropriately to obtain a complete streamlined 3D surface;

[0055] Step 6: Design holes on the streamlined 3D surface to reduce the wind load on the component itself and meet the drainage function requirements, so as to obtain a final form of an aerodynamic roof additional component.

[0056] It can be seen that the outer contour of the aerodynamic component in the present invention is obtained by numerical simulation of the flow field around the prefabricated cabin substation using computational fluid dynamics. After installing this type of aerodynamic component on the original structure, it scientifically changes the local aerodynamic shape, so that the flow field in the corner area of ​​the prefabricated cabin fits the contour of the component, suppressing the flow separation and vortex generation in the corner area of ​​the prefabricated cabin. Compared with the situation without such a component, or the simple open parapet structure used in previous studies, it can scientifically suppress the vortex and separation flow in the corner area of ​​the structure, thereby reducing the extreme negative pressure, improving the wind resistance safety of the structure, and having a simple and beautiful structure while meeting the functions.

[0057] Specifically, Figure 2 As shown, the above step 1 includes:

[0058] Step 101: constructing a three-dimensional geometric model of the prefabricated cabin building to obtain a three-dimensional geometric model of the prefabricated cabin building;

[0059] Step 102: Determine the size of the calculation domain of the three-dimensional model of the prefabricated cabin building, and obtain the three-dimensional calculation domain space after deducting the building;

[0060] Step 103: Using a meshing tool to perform mesh discretization on the obtained three-dimensional computational domain space to obtain a mesh model;

[0061] Step 104: Import the divided grid model into computational fluid dynamics (CFD) software to set boundary conditions to perform CFD simulation calculations under different wind direction angles.

[0062] Specifically, in the above step 101, the constructed three-dimensional geometric model of the prefabricated cabin building is constructed as a real-scale model according to the actual size of the prefabricated cabin building design or a scale model is constructed with an appropriate scale ratio. The model should reflect the main features of the actual building.

[0063] Specifically, the above step 102 includes:

[0064] Determine the size of the computational domain. The size of the computational domain should ensure that the maximum blockage ratio of the model along the wind direction is no more than 3%. The upstream inlet, downstream outlet, both sides, and top surface of the computational domain should be no less than 5, 10, 5, and 5 times the characteristic height of the building respectively (the characteristic height can be the height of the prefabricated cabin building). Import the 3D geometric model of the prefabricated cabin building into the computational domain, perform Boolean subtraction operations, and obtain the 3D computational domain space after deducting the building.

[0065] Specifically, the above step 103 includes:

[0066] The computational domain can be appropriately divided to improve the quality of meshing: the cylindrical space of the computational domain surrounding the building is used as the inner domain, and the area outside the building is used as the outer domain; a mixed meshing scheme of inner and outer domains is adopted, and the inner domain of the cylinder that wraps the building is unstructured meshed, and the outer domain is structured meshed to complete the mesh discretization of the entire computational domain. In this way, the calculation wind direction angle can be easily changed by rotating the inner domain without re-meshing. The mesh size and quality must meet the relevant requirements of numerical wind tunnel simulation.

[0067] Specifically, the above step 104 includes:

[0068] First, determine the landform type (A / B / C / D) around the building under study, and use the boundary condition mathematical model of the equilibrium atmospheric boundary layer to define the boundary conditions of the velocity inlet (see reference: Yang Y, Xie Z & Gu M. Consistent inflow boundary conditions for modelling the neutral equilibrium atmospheric boundary layer for the SST k-ω model [J]. Wind and Structures, 2017, 24 (5): 465-480.); the velocity inlet condition is used for the inlet, the pressure outlet condition is used for the outlet, the no-slip wall condition is used for the ground and building surface, and the symmetric boundaries are used for the two side surfaces and the top surface; after setting the boundary conditions, selecting the appropriate turbulence model (usually the SST k-ω model in the RANS Reynolds average method) and calculation parameters, perform CFD simulation calculations under different wind direction angles.

[0069] As a preferred design method of the new roof additional component of the substation prefabricated cabin in this embodiment, the method also includes:

[0070] Step 7: The final form of the obtained roof additional component is printed and produced using 3D printing technology to facilitate mass production.

[0071] Embodiment 2:

[0072] This embodiment takes a prefabricated integrated cabin building of a substation as an example. The building 3D model is as follows: Figure 4 The specific implementation and steps of the aerodynamic component designed by the present invention are as follows:

[0073] (1) According to the original cabin building design, the corresponding numerical wind tunnel model is established, such as Figure 5 , Figure 6 As shown in the figure, the flow field under the action of strong wind is simulated and calculated.

[0074] (2) Based on the distribution of the flow field around the prefabricated cabin obtained by numerical simulation, a wind speed cloud diagram on a certain cross section is drawn, such as Figure 7 Take a wind speed streamline in the wind speed cloud map as the target curve and use the spline curve for fitting.

[0075] (3) Draw a series of streamline curves (here 4) on the edge of the eaves of the corner area of ​​the prefabricated cabin roof, such as Figure 8 As shown, the curves at several different positions are fitted into a 3D streamlined surface, such as Fig. 9 shown.

[0076] (4) The above shows the process of fitting the 3D surface on one side of the corner area of ​​the prefabricated cabin by using streamlines. The method for the other side is the same. By changing the wind direction angle and performing simulation calculations, the streamlines on the other side can be obtained, and the surface can also be fitted.

[0077] (5) After obtaining the 3D streamlined surfaces on both sides, they are merged into a complete smooth, streamlined 3D surface, and then holes are evenly opened on the surface to reduce the wind load on the component itself and meet the drainage requirements of the corner area of ​​the component.

[0078] The final surface outline and top view dimensions are as follows: Fig.10 , Fig.11 The finished component diagram is shown in Fig.12 shown.

[0079] Embodiment 3:

[0080] See also Fig.13 As shown, the design device of the new type of additional roof component of the substation prefabricated cabin provided in this embodiment includes a processor, a memory, and a computer program stored in the memory and executable on the processor, such as an additional component design program for optimizing the wind load of the corner area of ​​the roof of the substation prefabricated cabin. When the processor executes the computer program, the steps of the above embodiment 1 are implemented, such as Figure 2 Steps shown.

[0081] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program in the design device for the new roof additional component of the substation prefabricated cabin.

[0082] The design device for the new type of additional roof components of the substation prefabricated cabin can be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The design device for the new type of additional roof components of the substation prefabricated cabin can include, but is not limited to, a processor and a memory. Those skilled in the art can understand that Fig.13 It is only an example of a design device for a new type of additional roof component for a prefabricated cabin in a substation, and does not constitute a limitation of the design device for a new type of additional roof component for a prefabricated cabin in a substation. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the design device for a new type of additional roof component for a prefabricated cabin in a substation may also include input and output devices, network access equipment, buses, etc.

[0083] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0084] The memory may be an internal storage unit of the design device for the new type of additional roof components of the substation prefabricated cabin, such as a hard disk or memory of the design device for the new type of additional roof components of the substation prefabricated cabin. The memory may also be an external storage device of the design device for the new type of additional roof components of the substation prefabricated cabin, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the design device for the new type of additional roof components of the substation prefabricated cabin. Further, the memory may also include both the internal storage unit and the external storage device of the design device for the new type of additional roof components of the substation prefabricated cabin. The memory is used to store the computer program and other programs and data required by the design device for the new type of additional roof components of the substation prefabricated cabin. The memory may also be used to temporarily store data that has been output or is to be output.

[0085] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made based on the essence of the content of the present invention should be included in the protection scope of the present invention.

Claims

1. A design method for a new type of additional roof component for a prefabricated cabin of a substation, characterized in that: include: Step 1: Establish a numerical wind tunnel model of the prefabricated cabin building; Step 2: Import the calculation result file of the wind direction condition perpendicular to the building facade wall in the numerical wind tunnel model into the CFD post-processing module for flow field visualization. First, select a section perpendicular to the eaves direction near the corner area of ​​the prefabricated cabin roof and display the velocity contour cloud map on the section. Step 3: Select a velocity contour line in the velocity contour cloud map as the target streamline; then use the same method to make several parallel velocity contour cloud maps, take the same velocity streamline in each cloud map, and make a series of target streamlines; fit each target streamline with a spline function curve, and then enclose the spline curve to form a 3D surface on one side of the corner area; Step 4: Using the above steps 2 and 3, similarly obtain a series of target streamlines on the other side of the roof corner area under another wind direction angle condition perpendicular to the front facade wall of the building, and fit the target streamlines to enclose another 3D surface; Step 5: Perform a Boolean addition operation on the two 3D surfaces on both sides of the building roof corner area obtained in Steps 3 and 4 above, and modify their boundary lines appropriately to obtain a complete streamlined 3D surface; Step 6: Design holes on the streamlined 3D surface to reduce the wind load on the component itself and meet the drainage function requirements, so as to obtain a final form of an aerodynamic roof additional component.

2. The design method of the new type of roof additional component of the substation prefabricated cabin according to claim 1 is characterized in that: The step 1 comprises: Step 101: constructing a three-dimensional geometric model of the prefabricated cabin building to obtain a three-dimensional geometric model of the prefabricated cabin building; Step 102: Determine the size of the calculation domain of the three-dimensional model of the prefabricated cabin building, and obtain the three-dimensional calculation domain space after deducting the building; Step 103: Using a meshing tool to perform mesh discretization on the obtained three-dimensional computational domain space to obtain a mesh model; Step 104: Import the divided grid model into computational fluid dynamics (CFD) software to set boundary conditions to perform CFD simulation calculations under different wind direction angles.

3. The design method of the new type of roof additional component of the substation prefabricated cabin according to claim 2 is characterized in that: In step 101, the constructed three-dimensional geometric model of the prefabricated cabin building is constructed as a real-scale model according to the actual design size of the prefabricated cabin building or as a scale model with an appropriate scale ratio.

4. The design method of the new type of roof additional component of the substation prefabricated cabin according to claim 2 is characterized in that: The step 102 includes: Determine the size of the computational domain. The size of the computational domain should ensure that the maximum blockage ratio of the model along the wind direction is no more than 3%. The upstream inlet, downstream outlet, both sides, and top surface of the computational domain should be no less than 5, 10, 5, and 5 times the characteristic height of the building, respectively. Import the three-dimensional geometric model of the prefabricated cabin building into the computational domain, perform Boolean subtraction operations, and obtain the three-dimensional computational domain space after deducting the building.

5. The design method of the new roof additional component of the substation prefabricated cabin according to claim 4 is characterized in that: The characteristic building height is the prefabricated cabin building height.

6. The design method of the new type of roof additional component of the substation prefabricated cabin according to claim 2 is characterized in that: The step 103 comprises: The cylindrical space of the computational domain surrounding the building is taken as the inner domain, and the area outside the building is taken as the outer domain. A mixed grid division scheme of inner and outer domains is adopted, in which the inner domain of the cylinder wrapping the building adopts an unstructured grid, and the outer domain adopts a structured grid, thus completing the grid discretization of the entire computational domain.

7. The design method of the new roof additional component of the substation prefabricated cabin according to claim 2 is characterized in that: The step 104 comprises: First, determine the landform type around the building under study, and use the boundary condition mathematical model that simulates the equilibrium atmospheric boundary layer to define the boundary conditions of the velocity inlet; the inlet adopts the velocity inlet condition, the outlet adopts the pressure outlet condition, the ground and building surface adopt the no-slip wall condition, and the two side surfaces and the top surface adopt the symmetrical boundary; after setting the boundary conditions, selecting the appropriate turbulence model and calculation parameters, carry out CFD simulation calculations under different wind direction angles.

8. The design method of the new type of roof additional component of the substation prefabricated cabin according to claim 7 is characterized in that: The suitable turbulence model is the SST k-ω model in the RANS Reynolds average method.

9. The design method of the new type of roof additional component of the substation prefabricated cabin according to claim 1 is characterized in that: Also includes: Step 7: The final form of the roof additional component is printed using 3D printing technology.

10. A design device for a new type of additional roof component for a prefabricated cabin of a substation, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

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