超临界CO_(2)再热再压缩布雷顿循环火力发电系统[火用]分析  

Exergy analysis of a fossil-fired power system with supercritical CO_(2) reheating and compression Brayton cycle

作　　者：刘国浩 余廷芳[1] LIU Guohao;YU Tingfang(School of Advanced Manufacturing,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学先进制造学院,江西南昌330031

出　　处：《南昌大学学报（工科版）》2023年第4期385-391,共7页Journal of Nanchang University(Engineering & Technology)

摘　　要：建立了超临界CO_(2)一次再热再压缩布雷顿循环火力发电系统模型,深入分析了各关键参数对系统性能的影响,研究了分流比对换热器夹点的影响规律,得到了对应的最佳分流比,同时分析了各部件火用损率的大小。结果表明:随着再热压力的升高,系统火用效率先上升后下降,存在最佳再热压力;对整个发电系统,锅炉是火用损最大的设备,而对热力循环,回热换热器是火用损影响最大的环节;由于分流的存在,系统火用效率受主压缩机出口压力和入口温度的影响并非单调变化;分流比的选取应综合考虑其对高温回热器和低温回热器回热度的影响,以使整体系统达到最优。The model of fossil-fired power system with supercritical CO_(2) reheating and compression Brayton cycle was established,the influence of various key parameters on the system performance was deeply analyzed,the impact of split ratio on the pinch point of heat exchanger and the exergy loss rate of each component was studied,the optimal split ratio was obtained.Results showed that,as reheat pressure increased,exergy efficiency went up first and then went down,indicating an optimal reheat pressure.For the whole power generation system,the boiler is the equipment with the greatest exergy loss,while for the thermal cycle,the regenerative heat exchanger is the link with the greatest exergy loss.Due to the shunt,exergy efficiency is not monotonically affected by the exit pressure and inlet temperature of the main compressor.In order to optimize the whole system,the influence of the split ratio on the heat recovery of high temperature regenerator and low temperature regenerator should be considered comprehensively in the selection of the split ratio.

关 键 词：超临界CO_(2) 布雷顿循环 再热循环 分流比 [火用]效率 

分 类 号：TK122[动力工程及工程热物理—工程热物理]