吸热器二次反射锥对太阳能斯特林热机吸热性能的影响研究

INFLUENCE OF SECONDARY REFLECTION CONE ON ENDOTHEMIC PERFORMANCE OF CAVITY RECEIVER IN SOLAR STIRLING ENGINE

分析太阳能斯特林热机腔式吸热器的结构特点,建立以二次反射锥结构参数为变量的腔式吸热器性能参数模型。以38 kW碟式太阳能斯特林热机为研究对象,采用光线追迹法模拟分析不同二次反射锥结构对腔式吸热器表面能流等性能参数的影响。结果表明:二次反射锥对吸热器表面能流密度分布和光能利用效率有着重要影响,其中外抛物面、双曲面、球面等反射锥能显著提高吸热器表面能流分布的均匀性,同时吸热器表面光能利用率分别提高25.6%、27.3%和28.6%,但存在光线溢出吸热器表面的现象;平顶圆锥和现有38 kW热机所采用的内抛物面二次反射锥虽不能改善吸热器表面能流分布均匀性,但光能利用率能分别提高30.5%和33.0%且无光线溢出。

The structural characteristics of the cavity receiver of the Stirling engine was analyzed and the parameter model of the receiver was built which vary by the structure parameter of the secondary reflection cone. With 38 kW dish Stirling system as the research object, ray tracing method was used to analyze the effects of different secondary reflection cones on the flux distribution of the cavity receiver. Results showed that the secondary reflection cone has important influence on the flux distribution and light use efficiency of the dish Stirling system. The paraboloid , hyperboloid and spherical reflection cone can improve the flux distribution uniformity of the receiver surface and the absorber light increasing rate is 25.6%, 27.3% and 28.6% respectively. But there is light overflow phenomenon on the surface of the receiver, the flat-topped cone and the S260 reflection cone cannot improve the flux distribution uniformity of the receiver, but the light increase rate was improved, the value are 30.5% and 33.0%, respectively and there is no light overflow phenomenon.