超超临界机组柔性快减负荷控制策略的研究与应用

Research and Application of Flexible RB Control Strategy for the Ultra-supercritical Unit

针对新一代超超临界机组的制造工艺及运行特点,优化升级(RUNBACK,RB)试验的控制目标,将直流炉机组RB过程中汽温突降裕度和汽动给水泵汽源保障2个关键控制目标纳入RB过程管控,提出柔性RB控制策略,并进行仿真模拟和柔性控制逻辑设计。根据各类型RB特点不同,将滑压速率、给水惯性时间、磨煤机跳闸间隔时间等核心控制参数,进行差异化设置和过程动态调整,采用燃料主控禁增、引风机动叶超驰关等手段优化控制效果。控制策略的应用结果表明,柔性RB控制策略的应用,能够保证在RB试验过程中机组快速减负荷并安全运行,机组主要参数控制效果良好。

Aimed at the manufacturing and operation characteristics of new generation ultra-supercritical unit,the control objectives of the RB testare optimized.Two key control objectives including steam temperature sudden drop margin and steam source guarantee of feed pump turbine,are brought into the RB process control.A flexible RB control strategy was proposed,and simulation and flexible control logic design were carried out.According to the characteristics of each type of RB,the core control parameters such as pressure changing rate,feed water inertia time,and coal mill trip interval were differentiated and dynamically adjusted.Control effects were also optimized by means including the prohibit increase of fuel master,and the overriding close of induced draft fan leaves.The application result of the control strategy indicates that,the flexible RB control strategy can ensure the load reducing promptly and steadily during the runback process of the unit,and the transition of major parameters remains smooth.