Modeling And Simulation Research Of DEH Control System For 350MW Circulating Fluidized Bed Unit

In recent decades circulating fluidized bed unit technology has become the main development direction of thermal power.Compared with the conventional pulverized coal furnace,circulating fluidized bed unit can improve the efficiency,reduce the coal consumption,the advantages of reducing missions of pollutants.But the combustion system of circulating fluidized bed is much more complicated than pulverized coal furnace.With the improvement of power system automation level,digital electric-hydraulic control system is widely used in the steam turbine unit.In order to further improve operation safety,efficiency and automation level of the circulating fluidized bed unit,it is necessary to transform and optimize the control logic of digital electric-hydraulic control system.While the thermal power simulation technology provides an online environment to modify the control program for the thermal control personnel,and they can verify this control scheme by using the simulation support system to meet the operation requirements of the actual unit.This paper takes 350 MW circulating fluidized bed unit as the research object.It expounds the composition and function of the steam turbine control system and further studies of the digital electric-hydraulic control system.It introduces in detail the simulation supporting environment OTS module library of commonly used control algorithms.The models of digital electric-hydraulic control system are built with these control algorithms,the models allows to achieve speed control,load control and valve management functions and so on.According to the actual operation data,debugging the models with the boiler,turbine,and electrical model combined.The unit can realize from the power transmission,ignition,heat booster,rush to turn,synchronization,load thrown on,and valves group activity test,leaking test,overspeed protection test and so on.The simulation results show that the control logic is rigorous,flexible and the function is consummate.The simulation model can better simulate the scene operation condition.In order to improve the safety and economy of the circulating fluidized bed unit,as well as the automation level of electric power system.It is necessary to constantly improve the control strategy of the unit.The advanced control strategy are gradually used in the actual scene.Thermal power simulation technology provides a reliable platform for this process.It can not only determine the feasibility of the new control scheme,but also implement pre-job training for operators.So that it can improve the level of operation and the ability of dealing with accidents and promote the development of digital electric-hydraulic control system.