燃气-蒸汽联合循环余热锅炉吹管工艺优化

Steam Purging Process Optimization for HRSG of Gas-steam Combined Cycle Unit

为提高余热锅炉吹管效率、增加吹管工作安全性,提出了一种稳压法和降压法相结合的吹管工艺,该工艺优化了吹管临时系统安装布置,保证了管路吹扫效果,提高了吹管效率;采取提高高压汽包水温,保持高压汽包水位,加强高压蒸发器定排,降低高压汽包升压速率等相应控制措施,解决了冷态启动时锅炉高压汽包上下壁温差超限的问题;采取先降压再进行吹扫的措施,解决了使用螺栓法兰连接固定的插入式靶板器造成的高压汽包升压超限的问题。打靶验收结果表明,锅炉蒸汽系统实际吹扫质量优良,吹管过程安全高效,相关经验可供后续同类机组借鉴。

In order to improve the efficiency and the working safety of steam purging,a steam purging process combining the pressure stabilization method with the pressure lowering method is put forward.The process optimizes the installation arrangement of the temporary system,ensures the purging effect of the pipeline,also improves the efficiency of steam purging.The water temperature of high-pressure steam drum is increased,the water level of the high-pressure steam drum is maintained,the regular discharge of the high-pressure evaporator is strengthened,and the pressure boost rate of high-pressure steam drum is reduced.The temperature difference between the upper and lower walls of the high-pressure steam drum of the boiler during cold start-up was solved by the corresponding control measures.The overpressure of the high-pressure steam drum caused by the inserting target plate fixed by bolted flanges was solved by reducing the pressure first and then purging.The results of shooting acceptance show that the actual purging quality of boiler steam system is excellent,and the process of steam purging is safe and efficient.Relevant experience can be used for reference by similar units in the future.