Control Strategy And Improvement Of RB Function In 660MW Power Unit

With the rapid development of power technology and the power industry,as well as the increase of resource, environment, economy Chinese face pressure.In order to improve the utilization rate of China energy, to vigorously develop the high parameters,large capacity supercritical, ultra supercritical unit has become an irresistible trend.Because supercritical and ultra-supercritical units with a more complex dynamic characteristics,which require reliable control system toensure its operational stability,security and economy. Therefore the operation parameters on the failure of automatic control system and the system automatically processing capacity requirements continue to increase, only through the operations of staff has been unable to meet the requirements for running unit, will result in thermal power unit and the operation stability. In order to solve the above problems, runback(RB) control has played an important role.RB control unit is in a state of normal operation, the main consideration when the tripping happens in the auxiliary equipment failure causes, through the unit coordinated control system(CCS) and furnace safeguard supervisory system(FSSS) whether, sequence control system(SCS) and the steam turbine control system(DEH) coordinated action, through online fast to calculate the maximum output of all the auxiliary machinery, when the crew instructions is greater than the maximum output, make the load to the maximum load, can withstand the target load after the unit returned to normal working state, reducing the unnecessary outage, enables the operation of the unit safety, economy and stability.In this paper, RB test in Guohua Dingzhou power plant 2 * 660 MW supercritical unit as an example, the supercritical unit RB control strategy and function were analyzed, combined with years of experience in the production of the first line of the accumulation of their own, as well as the domestic and foreign research status and control strategy of the RB RB field test data analysis and summary, the control strategy of RB before optimization and improvement. Finally, the dynamic data test in actual unit, the experimental results show that, the RB function design can meet the requirements of the operation of the unit, the realistic feasibility. The specific contents include: introduces the RB control of the background and the domestic and foreign research situation; research of RB control system and the control strategy of RB, and analyzes the common conditions for RB; study and analysis of the control strategy of the RB function, combined with the actual situation of the unit of pulverizing system and smoke control system RB control strategy. The optimization and improvement.