超临界350MW机组汽动引风机控制优化及其快速减负荷功能分析

Control optimization and runback analysis of steam-driven draft fans in a supercritical 350MW unit

依据某超临界350 MW机组汽动引风机系统设备性能,设计了汽动引风机的启动控制方案。借鉴国内机组的汽动引风机炉膛压力控制策略,结合该机组汽动引风机的特性及运行工况,对引风机入口导叶及引风机汽轮机转速2种炉膛压力控制方式之间的自动无扰切换进行了优化。从炉膛内风量质量守恒的角度分析了引风机快速减负荷(RB)试验结果,并给出了汽动引风机RB过程相对于电动引风机RB过程中炉膛压力变化趋势相反的原因,为优化同类型引风机控制提供依据。

According to performance of steam-driven draft fans in a supercritical 350 MW unit,the start control scheme of the steam-driven draft fans was designed. On the basis of furnace pressure control strategy of steam-driven draft fans in domestic units and combining with the characteristics and operating conditions of the steam-driven draft fans, the automatic and undisturbed switching of the entrance guide blade and tur- bine speed was improved. According to the process of run back （RB） test, the RB results were analyzed from aspects of flow mass conservation inside the furnace. Moreover, the reason why furnace pressure changed oppositely in RB test of steam-driven fans and in that of electrically driven fans was explained.