太阳能燃气联合循环系统典型日逐时特性分析

Analysis on typical daily hourly thermodynamic characteristics of integrated solar combined cycle system

以槽式太阳能集热场和燃气-蒸汽联合循环所组成的太阳能燃气联合循环(ISCC)为研究对象,结合热力学第一定律和第二定律对太阳能集热场及ISCC系统整体在4个典型日的热力学逐时特性进行研究。结果表明:随着太阳能辐射强度的增加,太阳能侧发电量也随之增加,而燃气-蒸汽联合循环发电(CCPP)系统发电量逐渐减小,形成互补趋势;随着太阳能辐射强度的增加,太阳能集热场的工质流量、集热场效率和光电转换率随之增加,ISCC系统的燃料基热效率和[火用]效率也随之增加,而[火用]损率逐渐减小,表明太阳能集热场的启用可以提升ISCC系统性能;对系统主要评价指标进行分析,得出系统年太阳能侧发电量为27.25 MW·h,年燃料节约率为3664.6 t,年CO2减排量为10077.66 t,年节省燃料费用为1210.64万元。该研究可为ISCC系统的设计及改造提供理论依据。

By taking an integrated solar combined cycle system(ISCC)consisting of trough solar field and conventional combined cycle power plant as the research object,the thermodynamic time-by-time characteristics of the solar field and the ISCC system in four typical days are analyzed,combining the first law and the second law of thermodynamics.The results show that,with the increase of solar radiation intensity,the solar power generation increases,while the power generation of CCPP decreases gradually,forming a complementary trend.In addition,with the increase of solar radiation intensity,the working fluid mass flow rate of solar field,the solar field efficiency,the solar-to-electric efficiency and the fossil fuel based thermal efficiency of the ISCC system increase,while the exergy destruction rate decreases.The results indicate that the performances of the ISCC system can be improved significantly by enabling the solar field.Moreover,according to analysis of the main evaluation indexes,the annual solar power generation is 27.25 MW·h,the annual fuel saving can reach up to 3664.6 t,the annual CO2 emission reduction is 10077.66 t,and the annual fuel saving cost is 12.1064 million yuan.The research can provide theoretical basis for design and retrofitting for ISCC systems.