汽轮发电机组超速保护对机组热力系统的影响

利用仿真软件对某发电机组的超速保护系统进行建模，模拟机组甩负荷和转子超速后功率负荷不平衡保护和超速保护的动作特性，分析超速保护动作对机组热力系统的影响.结果表明:当机组功率负荷不平衡保护和转子超速保护动作时，快关高调阀和中调阀，会导致阀前主蒸汽压力迅速升高，升至额定压力的1.1415倍，对机组阀门产生一定的冲击力，甚至导致安全阀超压，影响锅炉燃烧.功率负荷不平衡保护存在的唯一优点在于机组超速时能早于超速保护动作，但两种情况对控制超速的效果相差不大，相比较而言，误动作带来的危害更大. 

The Influence of OPC and PLU Protection on the Thermal System of Turbo-Generator Unit

The unit''s operating characteristics of power load unbalanced protection (PLU) and over-speed protection control (OPC) after load rejection and rotor overspeed was simulated. And the impact of overspeed protection action on the unit''s thermal system was analyzed. The results show that: when the unit''s power load unbalanced protection and rotor overspeed protection act, shutting the high-regulation valve and the intermediate-regulation valve quickly will cause the main steam pressure in front of the valve rising to 1.1415 times of the rated pressure rapidly. A certain impact force can take place on the valve of the unit, causing overpressure of the pressure-bearing components and the action of the safety valve, and ultimately leading to unstable combustion of the boiler. The only advantage of the power load imbalance protection is that, the unit can implement overspeed protection as early as the speed of the unit, but the two cases are all effective in the overspeed control. In comparison, the malfunction is more harmful.