| Based on the theory of Wilson,with the adoption of NACA63-215 airfoils and parameterized design concept,by applying Matlab and Solidworks softwares,a dual rotor air turbine applied in SCPPVC system has been designed.The air turbine blade airfoil blade has a long and thin shape,the root of which is thick,and with a small circular arc front.The blade is thin and has a sharp edge,the front curvature on the suface of airfoil shape is larger,whiler posterior curvature smaller.With the establishment of three-dimensional geometric model of the turbine,the structure and performance of dual rotor air turbine on SCPPVC system have been optimized by numerical calculation and experimental study.By a deep analysis on dynamic characteristics and flow field of optimized on,the structure of SCPPVC system of air turbine is finally obtained.According to the operation principle of the hot plate in the vertical solar chimney power plant,natural convection in a vertical air test bench with the simulation of solar heating is designed,and the double rotor air turbine produced by 3D printing technology is placed with zoom type flow guide barrel natural convection test platform and the performance of turbine rotor of double air within the SCPPVC system has been experimented.The experimental results show that under the same inlet wind speed,the optimal number of blades of the first rotor of the double rotor air turbine in SCPPVC system is 7,and the best radius ratio of the two stage rotor is about 0.75.In the numerical simulation,calculation region is calculated by using SST k-?turbulence model with multiple reference frame method,while radius and the first leaf number keep changing,the energy conversion performance of dual rotor turbine air SCPPVC system was analyzed,the pressure contours and the velocity contours are obtained in the system channel calculation area x-y section,while the results showed that:in the same radius ratio,when the number of leaf is increasing,the total output power of SCPPVC system in the two rotor air turbine increased first and then decreased,and when the number of leaves in the first stage rotor 7 it reaches the maximum;when the first rotor blades of the same number,when the radius ratio of two rotor increases,the total output power of double air turbine rotor increases first and then decreases,and when r/R=0.75,a double rotor air turbine total output power reaches its peak.The results are in agreement with the experimental results,and the error range is between 7%and 12%,which proves that the numerical simulation method is correct.Based on the correct numerical simulation method,the two-stage rotor spacing is optimized,and the performance is obtained when the distance is 0.70m.Therefore,in the SCPPVC system,when the NACA63-215 airfoil is adopted under the Wilson theory,the two level spacing of the dual rotor air turbine is 0.70m,the number of the first stage rotor blades is 7,and the radius ratio is 0.75,the maximum output power can be obtained.Based on the deep analysis of the optimal dual rotor air turbine obtained in the SCPPVC system,the numerical results show that the first stage rotor and second rotor turbine area with similar velocity and pressure distributions show good aerodynamic performance;the temperature rises gradually from the inlet of the 300K along the vertical direction,and reaches its highest temperature 309K at around the second rotor,then decreased rapidly,and reached the outside temperature 300K at the outlet,which indicates that hot air in the diversion channel,when flowing around the second rotor,has achieved heat transfer by expanding.Through the comparison of calculation results of numerical simulation,it can be obtained:with the change of the throat section of v_h turbine rotor speed,the total output power and output power of single rotor turbine showed a similar trend,and with the increase in the throat speed of v_h,presents index increasing.In the condition of the same inlet wind speed,dual rotor air turbine simulation power is increased by about50%~60%than the single the rotor air turbine simulation power,and with much more excellent performance;experimental results show that the output power turbine rotor and turbine rotor increases with the increase of v_h,but the total output power of double rotor air turbines is about 28%-39%higher than the total output power of single rotor turbine up.It shows that when the transmission loss and power loss are not considered,the energy conversion efficiency of dual rotor air turbine is higher,which is more consistent with the design requirements of SCPPVC system.The research results show that the dual rotor air turbine can effectively transform the kinetic energy and partial heat energy of the SCPPVC system,which provides a theoretical basis for the development of the turbine in the SCPPVC system. |
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