Building wind energy potential prediction method based on combination of urban actual climate and CFD simulation

Abstract

The invention relates to a building wind energy potential prediction method based on combination of urban actual climate and CFD simulation. The method comprises the following steps: acquiring urban wind climate data; establishing a corresponding model in CFD software according to a building grouping target needing to be researched; performing normalization processing on the wind speed data obtained by CFD simulation; according to a linear interpolation method, expanding existing wind direction data obtained by CFD simulation calculation into complete 360-degree wind direction data; calculating the wind energy potential of the research object by taking the obtained wind direction and wind speed cubic in the actual climate as the weight of wind energy potential calculation; modifying the research object model according to the optimization variable of the building group layout needing to be researched; and comparing the obtained calculation results of the wind energy potentials under different layouts, and selecting a building layout with better wind energy. According to the method, quantitative analysis of the building wind energy potential is realized, and powerful guidance is provided for building group layout optimization.

Description

Technical Field

[0001] The invention relates to a method for predicting building wind energy potential, and in particular to a method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation, and belongs to the field of urban and building simulation analysis. Background Art

[0002] At present, the application of renewable energy in the field of construction is developing rapidly, and wind energy has attracted much attention due to its good complementarity with solar energy. In recent years, how to make full use of wind energy resources to improve wind power generation efficiency through scientific and reasonable layout of buildings has become a key topic in the research of renewable energy in buildings.

[0003] In the study of urban wind environment, CFD (Computational Fluid Dynamics) simulation method has been widely used in the study of urban wind environment due to its economy and high accuracy. However, due to the constraints of CFD simulation input conditions, a simulation can only consider the wind energy flow field of the building under a single wind direction and constant wind speed, which to a certain extent restricts its prediction ability for complex actual environments.

[0004] At the same time, in actual urban environments, wind speed and wind direction change over time, and the prediction of wind energy potential of buildings should take into account the different distribution frequencies of wind speed and wind direction. If the wind energy of a building group is predicted based on a single wind direction, it cannot fully reflect the actual wind energy status of the building group.

[0005] Therefore, in order to solve the above problems, it is necessary to provide an innovative building wind energy potential prediction method based on the combination of actual urban climate and CFD simulation to overcome the above defects in the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide a method for predicting building wind energy potential based on the actual urban climate and CFD simulation, which can evaluate the wind energy potential of buildings and aims to quantitatively and comprehensively predict the impact of building group layout on wind energy potential, thereby providing powerful guidance for the optimization of building group layout.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation, which includes the following process steps: 1) Obtain urban wind climate data; 2) CFD simulation data acquisition: Establish the corresponding model in CFD software according to the building group target to be studied; 3) Normalization of simulation data: Normalize the wind speed data obtained by CFD simulation; 4) Calculate complete wind direction data: According to the linear interpolation method, the existing wind direction data obtained by CFD simulation calculation is expanded into complete 360-degree wind direction data; 5) Calculation of wind energy potential: Using the wind direction and the cube of wind speed in the actual climate obtained in step 1) as the weights for wind energy potential calculation, the wind energy potential of the research object is calculated; 6) Calculation of wind energy potential of different layouts: modify the research object model according to the optimization variables of the building group layout to be studied, and repeat steps 3) to 6); 7) Comparison of wind energy potential under different layouts: Compare the calculation results of wind energy potential under different layouts and select the building layout with better wind energy.

[0008] The building wind energy potential prediction method based on the combination of actual urban climate and CFD simulation of the present invention is further as follows: in the step 1), the urban wind climate data obtained covers the wind direction and wind speed data corresponding to each hour in 8760 hours in a typical year of the city.

[0009] The method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention is further as follows: in the step 1), urban wind climate data is obtained through a meteorological station or Chinese standard weather data.

[0010] The method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention is further as follows: Step 2) is specifically: 2-1), select a nine-square building group; 2-2), the 360-degree wind direction is evenly divided into 36 directions, and each direction corresponds to an independent simulation calculation; 2-3), collect the wind speed values ​​of each wind turbine installation location in different calculation directions.

[0011] The method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention is further as follows: the wind speed value in step 2-3) is solved by the following function: ; in: is the inlet wind speed function; k is the von Karman constant; z d is the zero plane displacement height; z0 is the aerodynamic roughness length; is the friction speed.

[0012] The method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention is further as follows: in the step 3), the power generated by the wind turbine is proportional to the cube of the received wind speed, and during the normalization process, the wind speed data is subjected to a cubic operation; The simulated data is normalized according to the following formula: in: Pointing at Wind energy conditions of the research object in terms of orientation angle; d refers to a certain orientation angle of the example, and there are m of them; i refers to a certain installation site of this example, and there are n of them in total; U i Refers to the simulated wind speed result of the ith installation location in the research object; U ref Refers to the reference wind speed of the installation site, that is, the wind speed at the same height as the installation site when it is not blocked.

[0013] The method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention is further as follows: in the step 4), interpolation is performed according to the following method: ; in: Pointing at Wind energy conditions of the research object in terms of orientation angle; and are two adjacent wind directions among the m existing wind directions obtained by CFD simulation; D stands for and Any wind direction in between that is not calculated by the CFD simulation.

[0014] The method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention is further as follows: in step 5), the method for calculating wind energy potential is: in: It is the wind energy potential prediction parameter of the research object; is the wind direction of the city at the kth hour of the year; is the wind speed of the city at the kth hour of the year; k refers to a certain hour in the typical year's meteorological data, and there are 8760 of them in total.

[0015] The method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention is also as follows: in the step 6), the variable of the orientation of the building cluster is optimized, and by changing the orientation of the building cluster, the inlet wind direction of the model is adjusted to 22.5°, 45°...337.5° of the original inlet wind direction in the CFD model to calculate the wind energy potential.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The building wind energy potential prediction method based on the combination of urban actual climate and CFD simulation of the present invention uses normalization, interpolation and weighted average methods to combine urban actual climate data with CFD simulation, solving the problem that the traditional CFD simulation prediction method only relies on a single wind direction and cannot fully reflect the actual wind energy conditions of the building.

[0017] 2. The present invention solves the problem of difficulty in quantitatively and comprehensively predicting the impact of building cluster layout on wind energy potential through scientific calculation methods and data processing procedures, realizes quantitative analysis of building wind energy potential, and provides powerful guidance for the optimization of building cluster layout.

[0018] 3. The present invention has strong adaptability and can meet the complex wind environment requirements of different cities, providing a scalable solution for optimizing the layout of building clusters.

[0019] 4. The present invention has good robustness and can operate stably under different research objectives such as arranging multiple installation sites at different locations of a single building or arranging installation sites in multiple buildings, and can effectively predict its wind energy potential.

[0020] 5. The present invention is flexible in terms of computing power investment. The number of CFD simulation calculations can be comprehensively adjusted according to the actual required result accuracy and the available computing power cost, so as to reasonably utilize resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the method for predicting building wind energy potential based on the combination of actual urban climate and CFD simulation of the present invention.

[0022] Figure 2 It is a line graph of wind climate data of a certain city in a specific embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of the building group of the present invention.

[0024] Figure 4 It is the wind energy potential calculation result of the specific embodiment of the present invention. DETAILED DESCRIPTION

[0025] Please refer to the instruction manual Figure 1As shown, the present invention is a method for predicting building wind energy potential based on the actual urban climate and CFD simulation, which includes the following process steps: 1) Obtain urban wind climate data; specifically, obtain urban wind climate data through meteorological stations or Chinese Standard Weather Data (CSWD). The urban wind climate data obtained should cover the wind direction and wind speed data corresponding to each hour in the 8760 hours of a typical year in the city, as shown in the attached Figure 2 shown.

[0026] 2) CFD simulation data acquisition: According to the building group target to be studied, the corresponding model is established in the CFD software. The specific process is as follows: 2-1), select a nine-square building group, as shown in the following Figure 3 For the convenience of calculation, in this embodiment, the model is set to a scale ratio of 1:300 with the actual size. b1 = H b2 = H b3 = 400 mm, L = D = 133.33 mm, W = 200.00 mm.

[0027] 2-2), based on the actual result accuracy requirements and the available computing power cost, the 360-degree wind direction is evenly divided into m directions as needed, and each direction corresponds to an independent simulation calculation. In this implementation, the 360-degree wind direction is evenly divided into 36 directions, and each direction corresponds to an independent simulation calculation. Figure 3 The model in is symmetrical, so only the 18 wind directions shown in the figure need to be calculated.

[0028] Furthermore, the installation location is set to 0.1H above the center of each building roof, where H refers to the building height. The software used for CFD simulation is FLUENT, and the calculation domain is H b1 For reference height, extend upwards 5H b1 , extending towards the wind inlet for 5 H b1 , extending 15 H towards the exit b1 , extend 5 H on each side b1; Use multi-region method for meshing, the mapping type is hexahedron, adjust and expand the building surface, the surface size is adjusted to 0.005 m, the thickness of the first expansion layer is 0.005m, the number of expansion layers is 5, and the growth rate is 1.2. In terms of boundary conditions, the inlet is velocity inlet, the outlet is set as pressure outlet, the upper and left and right boundaries use symmetry boundaries, and the building surface and the ground are no-slip boundary walls.

[0029] 2-3), according to the research needs, collect the wind speed values ​​of each wind turbine installation site in different calculation directions. Among them, the installation site is a single or multiple wind turbine installation locations outside the building facade in a single building or building group, which can be determined according to the actual needs of the research.

[0030] The wind speed value is solved using the following function: ; in: is the inlet wind speed function; k is the von Karman constant; z d is the zero plane displacement height; z0 is the aerodynamic roughness length; is the friction speed.

[0031] In this implementation, the specific parameters are k = 0.4, z d = 13 m, z0= 0.29 m, u* = 0.55 m / s, the collected data are shown in Table 1; 3) Normalization of simulation data: In order to ensure that the wind speed data obtained by CFD simulation can be compared with different urban environments or building cluster layouts, the wind speed data obtained by CFD simulation is normalized.

[0032] It should be noted that the sum of wind speeds at different installation locations or different wind directions cannot directly represent their power generation potential, and the power generated by a wind turbine is proportional to the cube of the received wind speed, so the wind speed data is cubed during normalization. Specifically, the simulation data is normalized according to the following formula: in: Pointing at Wind energy conditions of the research object in terms of orientation angle; d refers to a certain orientation angle of the example, and there are m of them; i refers to a certain installation site of this example, and there are n of them in total; U i Refers to the simulated wind speed result of the ith installation location in the research object; U ref Refers to the reference wind speed of the installation site, that is, the wind speed at the same height as the installation site when it is not blocked.

[0033] The normalized data are shown in Table 2: 4) Calculate complete wind direction data: Based on the linear interpolation method, the existing wind direction data obtained by CFD simulation calculation is expanded into complete 360-degree wind direction data.

[0034] In this step, interpolation is done according to the following method: ; in: Pointing at Wind energy conditions of the research object in terms of orientation angle; and are two adjacent wind directions among the m existing wind directions obtained by CFD simulation; D stands for and Any wind direction in between that is not calculated by the CFD simulation.

[0035] 5) Calculation of wind energy potential: Taking into account the differences in wind environments in different cities, the wind direction and the cube of wind speed in the actual climate obtained in step 1) are used as the weights for calculating wind energy potential, and the wind energy potential of the research object is calculated; Specifically, the method for calculating the wind energy potential is: in: It is the wind energy potential prediction parameter of the research object; is the wind direction of the city at the kth hour of the year; is the wind speed of the city at the kth hour of the year; k refers to a certain hour in the typical year's meteorological data, and there are 8760 of them in total.

[0036] According to calculations, the total wind energy potential of the nine installation sites of the building cluster in this embodiment under the climate conditions of a certain city is 1.70.

[0037] 6) Calculation of wind energy potential of different layouts: According to the optimization variables of the building cluster layout to be studied, modify the research object model and repeat steps 3) to 6).

[0038] In this embodiment, the variable of the orientation of the building cluster is optimized. By changing the orientation of the building cluster, the inlet wind direction of the model is adjusted to 22.5°, 45°...337.5° of the original inlet wind direction in the CFD model, and so on, and steps 3) to 6) are repeated to calculate the wind energy potential.

[0039] 7) Comparison of wind energy potential under different layouts: Compare the calculation results of wind energy potential under different layouts and select the building layout with better wind energy.

[0040] The results calculated in this embodiment are shown in the attached Figure 4 As shown, it can be found that the model has greater wind energy potential values ​​at 0° and 337.5°. Therefore, under the climatic conditions of a certain city, there will be better wind energy potential at 0° or 337.5°, that is, a layout facing north or northwest.

[0041] The above specific implementation methods are only preferred embodiments of the present invention and are 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 predicting building wind energy potential based on the actual urban climate and CFD simulation, characterized by: The process steps include: 1) Obtain urban wind climate data; 2) CFD simulation data acquisition: Establish the corresponding model in CFD software according to the building group target to be studied; 3) Normalization of simulation data: Normalize the wind speed data obtained by CFD simulation; 4) Calculate complete wind direction data: According to the linear interpolation method, the existing wind direction data obtained by CFD simulation calculation is expanded into complete 360-degree wind direction data; 5) Calculation of wind energy potential: Using the wind direction and the cube of wind speed in the actual climate obtained in step 1) as the weights for wind energy potential calculation, the wind energy potential of the research object is calculated; 6) Calculation of wind energy potential of different layouts: modify the research object model according to the optimization variables of the building group layout to be studied, and repeat steps 3) to 6); 7) Comparison of wind energy potential under different layouts: Compare the calculation results of wind energy potential under different layouts and select the building layout with better wind energy.

2. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 1, characterized in that: In the step 1), the urban wind climate data obtained covers the wind direction and wind speed data corresponding to each hour in 8760 hours in a typical year of the city.

3. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 2, characterized in that: In the step 1), urban wind climate data is obtained through a meteorological station or Chinese standard weather data.

4. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 1, characterized in that: The step 2) is specifically as follows: 2-1), select a nine-square building group; 2-2), the 360-degree wind direction is evenly divided into 36 directions, and each direction corresponds to an independent simulation calculation; 2-3), collect the wind speed values ​​of each wind turbine installation location in different calculation directions.

5. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 4, characterized in that: The wind speed value in step 2-3) is solved using the following function: ； in: is the inlet wind speed function; k is the von Karman constant; z d is the zero plane displacement height; z0 is the aerodynamic roughness length; is the friction speed.

6. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 1, characterized in that: In the step 3), the power generated by the wind turbine is proportional to the cube of the received wind speed, and during the normalization process, the wind speed data is subjected to a cubic operation; The simulated data is normalized according to the following formula: in: Pointing at Wind energy conditions of the research object in terms of orientation angle; Refers to a certain orientation angle of the example, there are m in total; i refers to a certain installation site of this example, and there are n of them in total; U i Refers to the simulated wind speed result of the ith installation location in the research object; U ref Refers to the reference wind speed of the installation site, that is, the wind speed at the same height as the installation site when it is not blocked.

7. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 1, characterized in that: In step 4), interpolation is performed according to the following method: ； in: Pointing at Wind energy conditions of the research object in terms of orientation angle; and are two adjacent wind directions among the m existing wind directions obtained by CFD simulation; D stands for and Any wind direction in between that is not calculated by the CFD simulation.

8. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 1, characterized in that: In step 5), the method for calculating wind energy potential is: in: It is the wind energy potential prediction parameter of the research object; is the wind direction of the city at the kth hour of the year; is the wind speed of the city at the kth hour of the year; k refers to a certain hour in the typical year's meteorological data, and there are 8760 of them in total.

9. The method for predicting building wind energy potential based on the combination of urban actual climate and CFD simulation as claimed in claim 1, characterized in that: In step 6), the variable of the orientation of the building cluster is optimized. By changing the orientation of the building cluster, the inlet wind direction of the model is adjusted to 22.5°, 45°, ... 337.5° of the original inlet wind direction in the CFD model to calculate the wind energy potential.

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