摘要
为了降低发电系统碳捕集的能耗以及提高电站整体供电效率,提出了一种基于煤富氧燃烧的超临界CO_2再压缩循环复合发电系统,并对系统进行了热力学分析与参数敏感性分析。结果表明,通过空分装置与热力系统集成可以使系统供电效率提高到43.75%,比无集成系统提高1.93%。锅炉损占总损的比例(82.29%)最大,回热器损占总损的比例(8.85%)次之。通过参数敏感性分析可以得到最佳透平出口压力是由循环最低温度所决定的,最佳透平出口压力曲线与CO_2饱和压力曲线基本重合;透平出口压力处于最佳值时,压比越大,供电效率越高。利用遗传算法对系统进行优化并与采用冷端优化后的超超临界燃煤机组进行对比,结果表明,在平均冷却水温度低于27℃的区域,该系统具有更高的供电效率以及更好的热经济性。
This paper proposes a composite power generation system based on the supercritical C02 recompression cycle of oxygen enriched combustion of coal. The main goals of this study are to reduce the energy consumption of carbon capture and storage and improve the overall generation efficiency. Thermodynamics and sensitivity analyses are conducted. The results show that the power supply efficiency can be increased to 43. 75% through the integration of air separation unit and thermodynamic system, showing an efficiency increment of 1.93%. The proportion of the exergy destruction of boiler to the total exergy destruction is found to be maximum （82.29%）, and the proportion of the exergy destruction of regenerator to the total exergy destruction is 8.85%. By means of sensitivity analyses, the optimal turbine outlet pressure is dependent on the lowest cycle temperature and is equal to the saturation pressure of the lowest cycle temperature. In addition, the power supply efficiency increases with the pressure ratio when the turbine outlet pressure is optimal. Finally, this system is optimized with genetic algorithm and compared with the ultra supercritical coal fired unit. It is shown that the system has higher power supply efficiency and better heat economy when the average temperature of the cooling water is lower than 27 ℃.
作者
冯雪佳
王顺森
FENG Xuejia;WANG Shunsen(Institute of Turbomachinery,Xi＇an Jiaotong University,Xi＇an 710049,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2018年第11期100-105,共6页
Journal of Xi'an Jiaotong University
关键词
富氧燃烧
超临界CO2
分析
热集成
ox-comhustion
supercritical CO2 cycle
exergetic analysis
heat integration
