塔式光热发电系统性能分析与评价

Performance analysis and evaluation for solar tower power plant

本文基于热力学第二定律,对塔式光热发电系统在给定镜场布置与太阳能辐射模型条件下的系统性能进行分析与评价,对各部件进行常规[火用]分析与先进[火用]分析,以发电系统中吸热器为研究重点,探究其运行与结构参数对吸热器性能的影响规律,通过先进[火用]分析对吸热器的不可逆性与系统耦合影响进行了量化分析,并对某30 MW塔式光热发电系统采用Ebsilon软件进行仿真模拟。仿真结果表明:在塔式光热发电系统中,各部件的内部[火用]损占比为60%~95%,表明各部件的性能改善主要应针对部件自身;而吸热器的[火用]损远高于其他部件,表明通过改善吸热器邻近设备性能而降低其外部[火用]损具有明显效果;吸热器的[火用]效率区间为45%~60%,为提高吸热器可用能的利用程度,除了提高吸热器自身热效率外,也可通过提高吸热器工质的温度等级得以实现。

On the basis of the second law of thermodynamics,this paper analyzes and evaluates the system performance of tower photothermal power generation system under the condition of given mirror field layout and solar radiation model,and carries out regular exergy analysis and advanced exergy analysis on each component.It focuses on the heat receiver in the power generation system,explores the influence law of the heat receiver’s operation and structural parameters on its performance,and quantitatively analyzes the irreversibility of the heat receiver and coupling effect of the system through advanced exergy analysis.The simulation of a 30 MW tower photothermal power generation system is carried out by Ebsilon software.The simulation results show that,in the tower photothermal power generation system,the internal exergy loss of each component accounts for 60%~95%,which indicates that the performance improvement of each component should be mainly against the component itself.The exergy loss of the heat receiver is much higher than that of other components,indicating that improving the performance of adjacent equipment of the heat receiver has obvious effect on reducing the external exergy loss.The range of exergy efficiency of the heat receiver is 45%~60%.To improve the utilization of available energy of the heat receiver,the heat efficiency of the heat receiver itself should be enhanced,and furthermore,the temperature grade of the working medium of the heat receiver should also be increased.