LNG冷能用于天然气富氧燃烧电厂碳捕获  

Application of LNG Cold Energy to Carbon Capture at Natural Gas Oxy-fuel Combustion Power Plant

作　　者：吴谋亮 管延文[1] 梁莹 刘文斌[1] 蔡磊[1] 吴勇 雷会姣 

机构地区：[1]华中科技大学环境科学与工程学院,湖北武汉430074 [2]中国市政工程中南设计研究总院有限公司,湖北武汉430010

出　　处：《煤气与热力》2016年第9期9-15,共7页Gas & Heat

摘　　要：构建一套将LNG冷能应用于天然气富氧燃烧电厂碳捕获过程的集成系统。该系统采用高压富氧燃烧方式,利用LNG冷能将烟气中的CO_2全部液化回收。一部分CO_2捕获封存,完成碳捕获过程,实现碳的零排放;另一部分CO_2用于富氧燃烧动力循环。由于LNG冷能的输入,碳捕获不需要烟气压缩过程,实现了近零功耗的碳捕获。利用Aspen Plus模拟软件对该集成系统进行模拟计算和优化分析,得到了CO_2循环物质的量流量(直接进入燃烧器与直接进入混合器的CO_2物质的量流量之和)、燃烧压力等参数对系统运行的影响情况。当燃烧器燃烧压力为3.5 MPa时,最佳CO_2循环物质的量流量为28.7 kmol/s,对应的最佳烟气温度(燃气轮机入口处混合烟气温度)为542℃。使用LNG冷能对CO_2进行捕获封存后,碳捕获过程能耗大为降低,系统净发电效率为50.48%。An integrated system using LNG cold energy for carbon capture at natural gas oxy-fuel power plant is built. The system is operated at high pressure in oxy-fuel combustion. CO2 in the flue gas is con- densed using LNG cold energy. Part of the condensed CO2 is captured and stored to realize the goal of near- zero emission of CO~, while the rest of the liquefied CO2 is used for recycle in the oxy-fuel combustion pow- er plant. Due to the application of LNG cold energy, the flue gas compression process of carbon capture is not required, thus near-zero power consumption for carbon capture is obtained in the system. Aspen Plus software is employed to simulate and optimize the oper- ating conditions of the system, and the influences of the recycle mass flow rate of COz （the sum of recycle mass flow rate of CO2 that goes directly into the burner and the mixer） and combustion pressure on the system operation are obtained. When the combustion pressure in the burner is 3.5 MPa, the optimum recycle mass flow rate of CO2 is 28.7 kmol/s, and the corresponding optimum temperature of the flue gas （the temperature of flue gas that goes into the gas turbine） is 542 ~C. The energy consumption of the carbon capture process is considerably reduced by using LNG cold energy. The net power generation efficiency is 50.48% under the optimized condition.

关 键 词：LNG冷能 碳捕获 富氧燃烧 高压燃烧 LNG电厂 

分 类 号：TE646[石油与天然气工程—油气加工工程]