M701SDA燃气轮机BPT偏差大跳机事件分析

某三菱M701SDA高炉煤气机组在大修后重新启动中发生BPT偏差大跳机事件。在燃气轮机点检后发现部分燃烧室及透平静叶出现附着物堆积和冷却孔堵塞的现象，从而引起BPT偏差大。经过现场检查和附着物的采样化验，判断煤气管道中大量的硫化铁附着物剥落进入燃气轮机燃烧室，生成氧化铁，在冷却空气的冷却下附着在燃烧室及过渡段内壁和静叶上。煤气管道中附着物的生成主要是由于煤气中粉尘量和硫含量严重超标所致。为了减少附着物的生成，提出了包括管道清洁和参数监视等若干改善对策和建议。

Analysis of BPT Spread High Trip of M701SDA BFG Gas Turbine

BPT spread high trip occurred in a MHI M701SDA BFG gas turbine in the time of restart after its major inspection. Depositions were found in the inner wall of some combustors, transition pieces and the surface of turbine vanes. Also, the cooling air holes of the hot parts were clogged by the deposition which caused the BPT spread high. After the site inspection and sampling of deposition, we found many FeS depositions fell away the fuel gas piping flew into the combustor and generated the Fe203 due to the high temperature. The Fe203 depositions cooled by cooling air and attached to the surface of hot parts. The extreme ovenproof dust and S concentration of fuel gas are the major cause of deposition in the fuel gas piping. In order to reduce the generation of deposition, some countermeasure including fuel gas purification and parameter monitoring are recommended.