联合循环参数和系统结构优化研究

研究了如何提高余热锅炉型三压再热联合循环系统的效率,应用分析的方法建立了系统效率数学模型,以联合循环系统效率最高作为系统性能的评判标准。在亚临界范围内,对余热锅炉的蒸汽参数进行了优化;针对余热锅炉进气温度对余热锅炉性能的影响进行分析,在此基础上提出燃气轮机排气部分回热利用,并研究了回热利用对联合循环效率的影响。计算结果表明:经余热锅炉优化和排气部分回热利用,在基本负荷下,PG9351FA机组的联合循环热效率可提高1.33%;在75%和50%的负荷下,效率分别提高2.11%和4.17%;而具有再热的GT26机组热效率高达60.73%。

Investigation of efficiency improvement of combined cycle power plant

The paper discusses the performance improvement of combined cycle with three-pressure,reheat steam cycle heat recovery steam generator(HRSG).The mathematical model of combined cycle is built using exergy analysis method and the minimal exergy loss of the combined cycle system is selected as the objective function to study the HRSG performance.Optimizing the steam parameters of HRSG under subcritical condition can increase the efficiency to F technology combine cycle.The influence of HRSG inlet gas temperature and gas to gas recuperation before entering the HRSG on the performance of steam cycle is simulated in this paper.The results show that by steam parameter optimization and the partial gas to gas recuperation the efficiency of PG9351FA combined cycle power plant increases by 1.33% at base load,(2.11)% at 75% load,4.17% at 50% load and that of reheat GT26 increases by 2.23% at base load,as high as 60.73%.