600MW机组热工主要保护系统的分析及完善

Analysis and optimization on the main protection system of thermal process in 600 MW units

对热工故障引起非计划停运次数较多的某电厂600MW机组热工主要保护系统进行了全面分析,发现主要是DCS(分散控制系统)接地系统、ETS(汽轮机危急遮断系统)、TSI(汽轮机监视仪表)、热工电源、阀门流量特性、部分逻辑及配置存在问题。针对这些问题进行了整改,并增加了停炉不停机功能,完善了SOE(事件顺序记录)、声光报警、管理制度等。整改后效果良好,2008年比2007年减少了5次热工原因引起的非停异停,并避免了7次其他原因引起的非停异停。

Non-plan shutdown caused by thermal control failure occurred many times in a 600 MW units. By analyzing the main protection system of thermal process, it was found that the main problems were： the hidden troubles in decentralized control system （DCS） grounding system, emergency trip system （ETS）, turbine supervisory instrument （TSI）, thermal process power supply, the flow characteristics of the valves, parts of logic and configuration. Some corrective measures such as adding function of boiler tripped without turbine tripping and optimization of sequence of events （SOE）, sound and light alarm system and management rules have been taken. After the reform, the non-plan shutdown caused by thermal control failure decreased by 5 times in 2008 comparing with in 2007 and 7 times of non-plan shutdown caused by other reasons were avoided.