天然气联合循环电厂CO_2捕获整体性能及成本敏感性分析

Performance and cost sensitivity analysis of natural gas combined cycle power plant integrated with CO_2 capture

为研究天然气联合循环(NGCC)电厂引入燃烧后CO_2捕获系统后电厂整体性能及成本,利用整合环境控制模型(IECM)模拟了一乙醇胺(MEA)吸收剂的燃烧后CO_2捕获NGCC(NGCC+CC)电厂运行情景,其中以无CO_2捕获的NGCC电厂作为参考,同时和等发电量的燃烧后CO_2捕获燃煤电厂(PC+CC)进行对比.为研究NGCC+CC电厂的电力均化成本(LCOE)、CO_2捕获成本及吸收剂再生能耗等关键指标,对各指标的主要影响因子进行了敏感性分析,以优化CO_2捕获系统的运行参数.研究结果表明:MEA吸收剂的燃烧后CO_2捕获系统会降低NGCC电厂的整体效率,效率损失为6.92%,从而导致LCOE升高,从896元/MWh增长至1 020元/MWh,而PC+CC电厂的效率损失为4%.NGCC电厂容量因子和天然气价格是LCOE的主要敏感因素,尤其是天然气价格.NGCC+CC电厂的CO_2捕获成本主要受电厂容量因子、天然气价格及CO_2去除率等影响.吸收剂再生能耗则与吸收剂浓度、蒸汽热含量、贫液负荷、气液比及热电效率等相关.

The overall plant performance and costs of the Natural Gas Combined Cycle(NGCC)power plant fitted with post-combustion CO_2 Capture(NGCC+CC)based on Monoethanolamine(MEA)and a no capture power plant are estimated by Integrating Environmental Control Model(IECM)and comparing with pulverised coal-fired power plant with Post-Combustion CO_2 Capture(PC+ CC)with equal power generation.Meanwhile,the key indexes such as the Levelized Cost of Electricity(LCOE),CO_2 capture cost and sorbent regeneration energy consumption are analyzed by using sensitivity analysis method to optimize main operating parameters.The results show that the overall efficiency of NGCC power plane decreases because of the CO_2 capture system after the combustion of MEA sorbent with its efficiency penalty reaching 6.92%so that LCOE increases from 896$/MWh to 1020$/MWh.However,the efficiency penalty of PC+CC power plant is 4%.Moreover,the natural gas price and capacity factor of NGCC power plant are more sensitive to the LCOE,especially the natural gas price.The capacity factor,the price of natural gas and CO_2 removal rate and other factors have an impact on the CO_2 capture cost of NGCC+CC power plant and the sorbent regeneration energy consumption is affected mainly by sorbent concentration,steam heat content,lean solution loading,liquid-to-gas ratio and thermoelectric efficiency.