600MW超临界机组旁路控制策略的研究

Study on The 600MW Supercritical Unit Bypass Control Strategy

针对高压旁路控制系统采用常规机组控制汽温波动幅度大、控制效果不理想的缺陷,采用600MW超临界机组旁路控制策略。该策略在直流锅炉设置专门的启动旁路系统来排除不合格的工质,在超临界机组启动和低负荷运行期间,在汽轮机负荷(蒸汽流量)达到最小给水流量以前,把蒸汽压力和给水控制延伸到启动旁路系统。通过试验表明,减温阀下游测量汽温的波动为-12℃,改进效果是相当显著的。

To overcome the shortcomings such as large steam temperature fluctuations and unsatisfactory control effects while adopting the conventional unit control in the high-pressure bypass control system, the 600MW supercritical unit bypass control strategy is adopted. A start-bypass system for once-through boiler is specially set in this strategy to exclude the unqualified working fluid; the steam pressure and water control will be extended to the start-bypass system during the startup and low-load operation of the supercritical units, as well as before the turbine load （steam flow） achieves the minimum water flows. Tests have showed that the improved effect is quite remarkable while the downstream measured temperature fluctuation of the temperature reduction valve is -12 ℃