中文摘要：

随着塔式太阳能发电技术的进步，如何布置高效低成本的塔式太阳能电站镜场，已成为提高太阳能集热效率的关键问题之一。其中，阴影和遮挡效率作为镜场光学效率的重要组成部分一直以来都是计算的难点。结合两种传统阴影和遮挡的计算方式——射线追踪法和平板投影法，提出一种新的计算方法，该计算方法包括高效的预判断模型和改进的效率算法两部分，将该算法与已有的改进算法进行对比，研究结果表明：不论是计算精度还是计算速度，改进后的算法都明显优于已有的改进算法。

英文摘要：

As solar power tower （SPT） technology develops, how to dispose high efficiency and low cost heliostat field of solar power tower becomes one of key question for improving solar thermal efficiency, and shadow and blocking efficiency is significant portion of the optical efficiency of heliostat field, which is always the core question. Based on two traditional calculation formulae of shadow and blocking, the Monte-Caro ray tracing method and the mapping method, a new arithmetic code for shadow and blocking efficiency was proposed, which was consisted of a predicting model and an improved computing method. The results indicate that the present code is superior to Noone＇ s code no matter in the computing accuracy or the computing velocity.