| Based on the energy analysis of solar chimney power plants with vertical collectors(SCPPVC system),starting from the design principle of wind turbine,using the Wilson design method,the blades of turbine of system was designed,and by using the methods of numerical calculation,the physical model was and improved,and the performance of the turbine was synthetically analyzed by the method of experimental research.Based on Bates theory,momentum theory and blade element theory,the structure of air turbine blade in SCPPVC system was designed by using Wilson design method and MATLAB software.In the process of design,the NACA63-215 airfoil which had relatively larger lift drag ratio combined with coordinate transformation principle,the three-dimensional coordinates of airfoil was calculated and extracted,and the physical modeling of air turbine blades was developed by using SOLIDWORKS software.According to the blade surface stress and capacitation when air turbine was operated,the each blade chord and twist angle of top and bottom surface was corrected,and the structure of blade root was optimized the designed,the initial shape of the air turbine blade was developed in SCPPVC system.The air turbine calculation area was meshed by using GAMBIT software.The inner field is an air turbine and its surrounding rotating area which was encrypted by triangular mesh.The external field was a static region which adopted same mesh.The FLUENT software is used to simulate the air turbine with the SST k-? turbulence model and the multiple reference coordinate system.The pressure diagram of the flow field,the velocity diagram,the pressure graph on the blade surface of the turbine,and the pressure diagram of the blade with different radius section were obtained.The results showed that the bladeand the flow field are in line with the blade rotation mechanism,and cloud diagram distribution was reasonable.Using numerical methods,the power of different wind speed and different pressure were analyzed,the results showed turbine power changes in accordance with the exponential relationship with the variation of the wind speed at the turbine inlet,and changes in accordance with the linear relationship with the variation of between and after the turbine.The blades of air turbine with different number of blades and different tip speed ratio were designed,with output power of wind turbine and the air utilization coefficient as the objective function.Its aerodynamic characteristics was studied by the numerical simulation and comparative analysis.The results showed that in the SCPPVC system,when the blade number is 7 and the tip speed ratio was up to 1.8,the air turbine had the best performance,and the best working range is less than 9m/s.The low speed wind tunnel experimental platform was used to study the performance of air turbine SCPPVC system.We obtained the output power of air turbine with different wind and difference pressure,and starting wind speed of air turbine under different blade numbers.The results showed the variation relation of turbine output power with the inlet velocity and pressure difference is similar to the simulation results.And the smaller the number of blades,the smaller the starting wind speed,and the difference was not significant.The difference of starting wind speed of different blades in each group was about 0.3m/s.The experimental results were compared with the simulation results.The results showed that the simulation results were consistent with the experimental results.When the wind speed was 7m/s,the output power obtained by the two methods of air turbines were basically same,the error was about 1.38%;and when the wind speed was greater than or less than 7m/s,the errors of two methods was slightly increased;when the wind speed was 9m/s,the maximum error was about 6.6%.Therefore,the air turbine blade designed based on the wind turbine design theory was applied to the SCPPVC system,and the design method provided a theoretical basis for further design and optimization of air turbine blade in SCPPVC system. |
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