联合循环电站改造为整体煤气化联合循环的粗煤气冷却

Options of Cooling Raw Syngas when Retrofitting NGCC to IGCC

研究了将PG9351FA燃气-蒸汽联合循环电站改造为整体煤气化联合循环(IGCC)时的粗煤气冷却方式,以及煤气冷却过程副产蒸汽的利用方式.改造的IGCC电站以输运床气化炉为气源,考虑了燃气轮机改烧中低热值煤气后的喘振裕度和出力限制,以及NOx排放的限制.根据粗煤气冷却方式及副产蒸汽利用方式的不同,构建并比较了4种改造方案.研究表明:通过将透平初温降低100℃,可保证燃气轮机燃烧热值为6.5MJ/m3的煤气,同时可保证压气机喘振裕度的减小量不超过10%;采用全热回收方式冷却粗煤气,且由饱和蒸汽轮机来消纳粗煤气冷却过程中副产蒸汽的改造方案的供电效率最高,为42.3%.

The options of cooling raw syngas when retrofitting PG9351FA natural gas combined cycle （NGCC） to an integrated gasification combined cycle （IGCC） power plant were discussed. The ways of adopting the by-product steam resulting from raw syngas cooling process were analyzed. A transport gasifier was applied to the retrofitted power plant as the source of syngas. The surge margin, maximum power output, and NOx emission constraint were considered in modeling the off-design behavior of PG9351FA gas turbine. Four retrofitting cases were discussed on the basis of options of cooling raw syngas and ways of adopting by-product steam. The results show that the gas turbine could consume the syngas with a lower heating value of 6.5 MJ/m3 while the compressor surge margin could decrease by only less than 10% when T3 decreased by 100 ℃. Moreover, applying the total heat recovery method to cool syngas and a saturated steam turbine to adopt the by -product steam could lead to a net efficiency of 42. 3%, the highest in four retro- fitting cases.