Zero-Emission Combined Power Cycle Using LNG Cold

对一种潜在的零排放液化天然气(LNG)联合发电厂进行了研究。二氧化碳(CO2)-蒸汽的混合物被用作燃气轮机循环的工质，它取代了常规的空气中燃烧产物和空气，特别是作为控制火焰温度的热镇流器。氧(O2)用作燃料氧化剂，从空分装置(ASU)获得。燃烧产生的过量二氧化碳由简单的流动分离器提取并液化，准备重复使用和/或隔离。利用Aspen-plus软件进行热力学分析，提出了几种循环形式，并进行了比较。首先讨论了循环的装置结构和热力学，然后通过100%和120%化学计量燃烧的比较，计算了装置的最佳总效率。根据目前可用的材料和冷却技术，根据压力和温度水平进行优化的总体净效率约为56%(LHV基础)，包括空分装置和二氧化碳分离的能量损失。

A potential zero emission combined power generation plant fired by liquefied natural gas (LNG) has been investigated. A mixture of carbon dioxide(CO2)-steam is used as the working fluid of a gas turbine cycle, which replaces the normal combustion-in-air products and air, notably as the thermal ballast for the control of flame temperature. Oxygen (O2) is used as the fuel oxidant and is obtained from an air separation unit (ASU). The excess CO2 due to combustion is extracted by a simple flow separator and liquefied ready to be reused and/or sequestered. We proposed several types of cycles and compared with each other by analyzing them thermodynamically with the aid of ASPEN-PLUS software. The plant configuration and thermodynamics of the cycle are discussed first and then the optimised overall efficiency of the plant is calculated with a comparison of 100 % and 120 % stoichiometric combustion. The overall net efficiency, optimised to pressure and temperature levels complying with the material and cooling techniques currently available, is around 56 % (LHV basis), including the energy penalty of the ASU and the CO2 separation.