增压O_2/CO_2燃烧热力系统建模及压力优化

Simulation and Optimization of Pressurized Oxy-fuel Combustion System

O2/CO2燃烧技术是一种有效的燃煤电站减排CO2技术,由于增加了空气分离系统(air separation unit,ASU)和烟气净化压缩系统(CO2 compression and purification unit,CPU),O2/CO2燃烧电站发电效率降低。当系统压力提高,烟气中的水蒸气潜热得到回收,可以有效提高系统发电效率。利用Aspen Plus软件对330MW增压O2/CO2燃烧电站进行全流程建模并展开效率分析,获得压力对各子系统及全流程系统的影响情况。结果表明:产品氧气压力由0.135MPa提升到3MPa时,制氧功耗增加了39.64%;系统压力由常压增加到3MPa时,CPU功耗降低71.10%;系统存在最佳运行压力,最佳运行压力与排烟温度有关,排烟温度由60℃增加到122℃时,最佳运行压力由0.4MPa提高到1.6MPa。

Oxy-fuel combustion is an effective technology that can mitigate CO2 emission in thermal power plants. Due to the addition of air separation unit （ASU） and CO2 compression unit （CPU）, the efficiency of thermal system is reduced. While the system pressure increases, the latent heat can be recovered and then the efficiency increases. Aspen Plus was used to simulate and analyze the thermal system of 330MW pressurized oxy-fuel combustion. The results indicate that with the elevation of O2 pressure from 0.135 MPa to 3 MPa, the ASU power consumption increases by 39.64%; while the power consumption of CPU reduces by 71.10% when the pressure increases from 0.1013MPa to 3MPa; there is an optimum operating pressure dependent on the exhaust gas temperature, and the optimum operating pressure increases from 0.4 MPa to 1.6 MPa while the exhaust gas temperature increases from 60℃to 122 ℃.