大型碟式太阳能聚光器三维定常风场数值仿真

Large Dish Solar Concentrator for Numerical Simulation of Three Dimensional Steady Wind Farm

在太阳能发电系统聚光器结构优化设计中,研究25kW碟式光热太阳能发电系统聚光器的表面风载荷及流场特性问题。为提高发电效率,通过建立聚光器在不同工况下的流域模型,并采用标准k-ε湍流模型对流域进行数值仿真计算。结果表明,聚光器在90°高度角即开口朝上且缺口处于背风位置时为最优大风避难位置,最不利工况为90°-60°;聚光器处于最优避风位置时边缘的部分分区体型系数达到-1.54,需要对边缘反射镜进行加固处理;聚光器背风面附近形成的强烈大旋涡能够起到均匀风压的作用,而在流动分离后形成沿流向发展的非稳定螺旋涡会导致螺旋涡发生处负压很大。计算结果可为碟式聚光器或碟式光热太阳能整机结构优化设计提供参考。

Study the problem of surface wind load and the flow field characteristics of 25KW dish thermal solar power system＇s concentrator. Through Fluent platform, we built a watershed model of concentrator in different condi- tions, and used the standard k-e turbulence model for numerical simulation of watershed. The results show that the concentrator at 90° high angle, i.e. at the opening up and the gap in the leeward position, is at the optimal wind shelter location, the most unfavorable condition is 90°-60° high angle; some partition＇s shape coefficient on the edge of the concentrator at the best wind shelter locations reaches negative 1.54, reinforcement for the edge of the mirror is necessary; strong vertexes around the concentrator＇s leeside have the effect of uniform wind pressure, however, formed after the flow seperation along the flow direction in the development of the unstable spiral vortex will lead a big negative pressure. The results provide some reference for the wind-resistant design of dish concentrators or dish of photothermal solar machine.