三压再热余热锅炉蒸汽压力值热经济学优化

Investigation on the Generation Cost of Combined Cycle Power Plant Based on the Structural Theory of Thermoeconomics

研究余热锅炉与汽轮机之间蒸汽参数的优化匹配,已成为联合循环机组降低发电成本的重要手段之一.基于热经济学结构理论方法,建立了三压再热余热锅炉蒸汽参数的热经济学优化模型,选择以联合循环系统的发电成本小化为优化目标,提出一种基于三因素五水平的正交实验样本的优化算法,获得了余热锅炉蒸汽系统的高、中、低压蒸汽的压力的优化解.算例表明:优化结果与设计工况相比,功率增加8.93 MW,发电成本减小1.76%.

Along with the completion of the ＂West-East＂ project in China,as well as the construction of the ＂gas transmission from Sichuan province to eastern provinces＂ and the further development of gas in East China Sea,combined cycle power plants（CCPPs）have been developed quickly in the past couple of years. The traditional evaluation method based on the flint and second law of thermodynamics does not consider the influence of non-energy cost. Firstly, the cost model of CCPP is established based on the thermoeconomic structural theory. Secondly, considering the importance of internal parameters, two internal parameters,such as compressor pressure ratio and the outlet temperature of gas turbine, are selected and investigated when designing the CCPP. Lastly, considering regional difference and seasonal difference, the way how the natural gas price change and environment temperature influence on the CCPP＇s generating cost are studied respectively. These researches will support the thermoeconomic optimization of CCPP and provide a reference for investors or policy makers.