660MW超超临界机组主汽温波动原因分析

Analysis on the cause of main steam temperature fluctuation of 660 MW ultra-supercritical unit

某电厂660 MW超超临界机组在稳态和变负荷期间主汽温度波动过大,导致机组安全运行存在严重事故隐患。通过对该机组历史数据和控制策略的分析研究,指出了自动控制系统中协调控制策略、给水控制策略和汽温控制策略中多处设计不合理的隐患,根据该机组的设备实际运行情况,为机组的安全运行提出了一系列的控制策略和控制参数优化方案。方案实施后,机组的安全稳定性能得到了较大的提高。通过模拟量控制系统性能测试,主汽温度在稳态和变负荷期间品质指标达到同类机组的优良标准;控制策略优化效果显著,机组经济效益明显。

In view of a case caused by the excessive fluctuation of main steam temperature under stable and load variation conditions in a 660 MW uhra-supercritical power unit, which leads to serious hidden troubles to normal operation, by analyzing the historical data and control strategy of the unit, some hidden troubles of coordinate control strategy, feed-water control strategy and steam temperature control strategy in automatic control system was pointed out, furthermore according to the operation situation, a series of control strategy and control parameter setting optimization schemes was proposed. After the optimization, the safety and stability of this unit were improved greatly. By modulation control system performance test, index of main steam temperature quality achieves excellent standard of similar units under stable and load variation conditions, the control strategy optimization acquires significant effects and economic benefits.