中文摘要：

以北京延庆抛物面槽式太阳能集热系统作为研究对象，根据太阳位置变化情况，通过理论计算水平南北轴抛物面槽式集热器自东向西跟踪过程中采光平面上的太阳入射角，分析线性聚焦抛物形反射镜面对吸热器的余弦效应和端损失效应，提出抛物面槽式集热器有效太阳投入能量的概念，并对实验测得的典型日法向直射辐照度进行修正和对比。研究结果表明：余弦效应对抛物面槽式集热器的影响最为明显，约占到日输入能量的15％；对于两列相同结构的抛物面槽式太阳能集热器，长度越短，受到的端损失效应影响越大；特别是，当集热器长度超过100m时，端损失效应的影响会不足1％，因此可考虑忽略此修正。

英文摘要：

As the Beijing Yanqing parabolic trough solar collector system is the research object, solar incidence angle on the aperture plane of the parabolic trough solar collector was computed according to the variation in solar position when the collector tracks from east to west along the horizontal north-south axis. Caused by the structure of linear-focus parabolic surface and the receiver, cosine and end loss impacts were analyzed. In addition, the concept of the effective input energy from the sun was defined, and the experimental data of direct normal solar irradiance measured in a typical day was modified and compared. Results show that the cosine impact yields a loss of 15% daily energy in the typical day, which plays the leading role in the input energy to parabolic trough solar collectors; for the two rows of parabolic trough solar collectors with the same structure, shorter length makes larger end loss impact; especially, the end loss impact is less than 1% when the length is beyond 100 meters, so that it may be neglected.