CCPP机组余热锅炉高压蒸发器泄漏分析与处理

Analysis and Treatment of Leakage for High Pressure Evaporator of Waste Heat Boiler in CCPP(Combined Cycle Power Plant)

燃气-蒸汽联合循环机组(CCPP)作为高效能源转换系统,在钢铁等工业领域得到广泛应用。余热锅炉作为CCPP机组的核心部件,其稳定运行直接关系到整个机组的效率和安全性。文章针对某钢厂燃气轮机组配套余热锅炉高压蒸发器上部迎烟气面频繁泄漏问题进行了深入研究,分析泄漏原因为其下联箱内沉积物导致蒸发器管内水流量减小,进而产生汽水混合物的冲击腐蚀,同时炉膛局部区域的“烟气走廊”现象加剧了这一腐蚀过程。针对这一问题,采取更换泄漏管段、改造下联箱定排管系统以提高排污效率、修复和完善烟气挡板以减少“烟气走廊”形成、优化定期排污操作以及制定定期的检查和维护计划等措施,有效地解决了高压蒸发器的泄漏问题,提高了设备的稳定性和安全性。

As an efficient energy conversion system,the combined cycle power plant(CCPP)is widely used in such industrial fields as iron and steel.As the core component of CCPP,stable operation of waste heat boiler directly affects efficiency and safety of the entire unit.In the paper,the in-depth study aiming at frequent leak problem at the upper part of high pressure evaporator of supporting waste heat boiler facing flue gas in gas turbine unit of a steel plant is carried out as well as the leakage causes are analyzed to be that the deposit sediment in its lower header causes water flow rate in evaporator tube to be decreased so that impingement corrosion of steam water mixture is generated.Meanwhile,the phenomenon of“flue gas corridor”in local area of furnace exacerbates the corrosion process.For these problems,such measures as replacing leaking pipe section,reforming periodic discharge pipe system of lower header to improve efficiency of pollution discharge,repairing and perfecting gas baffle to reduce formation of“flue gas corridor”,optimizing periodic pollution discharge operations as well as formulating periodic plans of inspection and maintenance are taken to effectively solve the leak problem for high pressure evaporator so that the stability and safety of equipment are improved.