太阳能燃气联合循环发电系统能效优化与给水控制分析

The Energy Efficiency Optimization and Feedwater Control Analysis of Integrated Solar Combined Cycle

太阳能燃气联合循环系统(ISCC)是将槽式太阳能与燃气轮机联合循环相结合,充分利用太阳能作为中低温热源,是提高太阳能发电效率,降低太阳能发电成本,并减少系统CO_2放的有效途径。太阳能能流密度低,易受气候和昼夜影响,在阴雨和夜间,太阳能集热器几乎停止工作,造成系统工作不稳定。基于以上太阳能发电系统的缺点和不足,根据最优给水比研究,采用比值控制法,使集热器给水比例匹配设计最优给水比,既满足发电系统的高效稳定运行,又达到对系统的给水调节。结果显示,采用太阳能集热器变比值给水,系统热效率、效率、太阳能净发电效率以及系统燃料基热效率稳定在0.558、0.55、0.185以及0.65;而定比值给水,随着DNI的下降,效率有所下降,下降百分比分别为:0.015、0.032、0.1以及0.038。控制系统模型在Matlab/Simulink平台上做仿真验证,通过仿真验证设计控制系统对ISCC系统集热器给水调节的准确度与可靠性。

The Integrated Solar Combined Cycle is a combination of trough collector and gas turbine combined cycle.It is an effective way to make full use of solar energy as a low-temperature heat source to improve the efficiency of solar power generation,reduce the cost of solar power generation and release the emission of CO2.Solar energy is a kind of low flux energy which are affected by the weather and the day and night.During the rainy day and night,the solar collectors almost stopped working which result to the unstable of system.Based on the shortcomings and deficiencies of solar power system,according to the study of optimal water ratio,ratio control method was used to make the proportion of water of the solar collector in accordance with the designed optimal water ratio.Not only dose it meet the efficient and stable operation of power generation system,but also to meet the regulation of water supply of the system.The result show that the percentage of thermM efficiency, exergy efficiency,net solar power efficiency and fuel thermal efficiency of system are stabled at 55.8, 55,18.5 and 65which adopt to the changed ratio control method.But the given ratio of water supply, with the decline of DNI,the efficiency has declined.The percentage has respectively declined 1.5, 3.2,10 and 3.8.The control system model is simulated on the platform of Matlab/Simulink and the accuracy and reliability of the design control system for the collector regulation of the ISCC system are verified through simulation.