整体煤气化联合循环系统空分单元集成特性

Integrated Characteristics of Air Separation Unit Scheme in Integrated Gasification Combined Cycle System

研究整体煤气化联合循环(integrated gasification combined cycle,IGCC)系统空气分离单元(air separation unit,ASU)的集成特性。对ASU主要操作参数分析结果表明,提高空气压缩机压比会导致空气精馏分离过程困难,消耗的空气压力能有所增加,但是提高空气压缩机压比有利于降低ASU的制氧功耗及提高IGCC系统供电效率。综合考虑IGCC系统NOx排放限制以及制氧比功耗,推荐适合IGCC系统的ASU出口氧气纯度为0.85。对ASU与燃气轮机集成度分析表明,IGCC系统供电效率随着集成度的增加先提高后降低,集成度在0.80时,IGCC系统供电效率最高。另外,与独立空分方案相比,采用整体空分方案的IGCC系统通过开发利用燃气轮机抽气显热,其供电效率有进一步提高的潜力。

The integrated characteristics of air separation unit（ASU） in integrated gasification combined cycle（IGCC） were analyzed.The results show that increase of air compressor pressure ratio made the air separation process difficult,and caused increase of air pressure potential energy consumption in air distillation separation process.While increased pressure ratio was beneficial to reduce the power consumption for oxygen production and increase the power generation efficiency of IGCC.Comprehensively considering the NOx emission and power consumption for oxygen production,0.85 oxygen purity of ASU was recommended for IGCC system.The integrated characteristics of ASU and gas turbine showed that power generation efficiency of IGCC system increased first and then reduced with ASU integration degree increasing,and the highest power generation efficiency of IGCC could be achieved at the integration degree 0.80.Furthermore,compared with independent ASU scheme,IGCC system with the integrated ASU scheme hold potential to improve power generation efficiency,considering sensible heat of air drawn from gas turbine compressor could be exploited in the future.