采用超临界二氧化碳动力循环回收燃气轮机排气余热的系统优化研究  

Optimization of system using supercritical carbon dioxide power cycle to recover waste heat from gas turbine exhaust

作　　者：张旭伟 白文刚[1] 吴家荣 李红智[1] 杨玉[1] 姚明宇[1] ZHANG Xuwei;BAI Wengang;WU Jiarong;LI Hongzhi;YANG Yu;YAO Mingyu(Xi’an Thermal Power Research Institute Co.,Ltd.,Xi’an 710054,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710054

出　　处：《热力发电》2021年第5期43-50,共8页Thermal Power Generation

基　　金：国家自然科学基金项目(51806172)。

摘　　要：采用超临界二氧化碳(S-CO_(2))动力循环回收燃气轮机排气余热可以提高系统性能,增加系统灵活性,减小系统体积。为此,本文采用遗传算法,以Taurus 60燃气轮机排气为热源对4种S-CO_(2)动力循环构型进行优化。结果表明,采用高、低温2级加热器布置的循环构型4输出净功最高,为3.20 MW,和单独的燃气轮机相比,可使系统热效率提高17.78百分点,是回收燃气轮机排气余热发电的优选构型。针对S-CO_(2)动力循环冷源损失较大的问题,进一步集成以液化天然气(LNG)为冷源的跨临界二氧化碳(T-CO_(2))动力循环回收S-CO_(2)动力循环冷源余热,可以进一步增加输出净功1.23 MW,使系统热效率进一步提高6.86百分点。对预冷器进行夹点分析可知,最小换热温差出现在预冷器热端,未出现夹点效应,满足设计要求。Using supercritical carbon dioxide(S-CO_(2))power cycle to recover waste heat from gas turbine exhaust can improve system performance,increase system flexibility and reduce system volume.In this paper,by employing the genetic algorithm,four S-CO_(2) power cycle configurations are proposed and optimized to recover the exhaust waste heat of gas turbine Taurus 60.The results show that,the configuration 4 with two-stage heater(high temperature heater and low temperature heater)has the highest net power output(2.30 MW),which can increase the system thermal efficiency by 17.78 percentage points and is suitable for gas turbine exhaust waste heat recovery.To solve the problem of large energy loss of the S-CO_(2) power cycle cold source,a transcritical CO_(2)(T-CO_(2))power cycle with liquid natural gas(LNG)as the cold source is further employed to recycle the waste heat of S-CO_(2) power cycle,which can further increase the net output by 1.23 MW,and the system thermal efficiency by 6.86 percentage points.The pinch point analysis for the pre-cooler shows that,the minimum heat exchange temperature difference occurs at the hot end of the pre-cooler,which means no pinch effect has occurred and the system meets the design requirements.

关 键 词：燃气轮机 余热回收 S-CO_(2)动力循环 T-CO_(2)动力循环 遗传算法 

分 类 号：TK123[动力工程及工程热物理—工程热物理]