汽轮发电机组转速波动分析与调节汽阀改进设计

Analysis of Speed Fluctuation and Improved Design on Governing Valve of Steam Turbine Generator

针对某船用汽轮发电机组出现的大幅转速波动问题进行分析,得出转速大幅波动的主要原因为:调节汽阀是按照喷嘴调节方式所设计的,与前两组喷嘴实际为节流调节的结构不匹配,因此,蒸汽流量-升程曲线的线性度不足,而调速器的校正功能又不足以补偿,导致在20%负载及空载工况下转速出现大幅波动。鉴于此,通过减小调节汽阀阀碟锥角,并对升程进行调整。试验结果表明,调节汽阀优化后,汽轮机调速系统运行平稳,转速大幅波动现象得以消除。

This study focuses on the speed fluctuation of a steam turbine generator. Through theoretical analysis, three main causes which lead to the fluctuation are deduced to: the governing valve was designed based on the nozzle control method, which do not match to the Structures of throttle adjustment. The curve of mass flow rate with distance was nonlinear and the speed governor's correct function is not enough to compensate it which lead to the speed fluctuation at the 20% and 0% load working condition. Based on the analysis, the degree of cone and the distance of governing valve were adjusted. The experimental results showed that the speed governing system was stably operating and the speed fluctuation was eliminated.