基于IGCC的燃烧前CO_2捕集抽蒸汽策略研究

Study on the Steam Extraction Strategy of Pre-combustion CO_2 Capture Based on IGCC

为了降低燃烧前CO2捕集对IGCC蒸汽动力系统出力的不利影响,并保证CO2捕集系统的稳定运行,CO2捕集消耗的蒸汽需要合理的从IGCC系统内部抽取。采用仿真模拟软件,研究了CO2捕集对IGCC系统中燃气轮机、余热锅炉和汽轮机负荷的影响。提出了两种水–气变换反应加湿蒸汽抽汽方案,通过对比这两种加湿蒸汽抽汽方案对汽轮机出力的影响,确定了最优的向CO2捕集系统供汽策略。其中,水-气变换反应加湿蒸汽从气化炉汽包抽取,CO2分离过程消耗的低压加热蒸汽将根据负荷情况由余热锅炉低压蒸汽系统或汽轮机低压缸抽取。

To reduce the negative influence of pre-combustion CO2 capturing on the IGCC steam turbine performance and to maintain the stability of CO2 capture system operation, the steam consumed by CO2 capturing needs to be properly extracted from integrated gasification combined cycle（IGCC） system. Through process simulation, the effects of CO2 capture on the load of gas turbine, heat recovery steam generator, and steam turbine in the IGCC system are studied. Two methods of steam extraction for water-gas shift reaction humidification are proposed and the better one is recommended by comparing the effect of these two approaches on the steam turbine load. It was shown that the humidification steam for water-gas shift reaction should be extracted from gasifier steam drum, and the low pressure heating steam consumed by CO2 separation process should be extracted from the low pressure steam system of heat recovery steam generator or from the low pressure cylinder of the steam turbine depending on the load conditions.