Simulation Research On Dynamic Characteristics Of600MW Thermal Power Unit

With the rapid economic development in our country, the demand of electricity isincreasing gradually. Among the new built power plant units, most of the single unitsare the600MW super critical units. So the dynamic characteristics study on the600MW super critical units will be of practical significance for the safe and economicoperation of power plants.This thesis study is based on a600MW super critical unit by using the massconservation equation, energy conservation equation, momentum conservationequation to build the boiler system mathematical model including water wall,over-heater, reheater, pressurized flow channel, wind-flue gas channel, and steamturbine system mathematical model including steam turbine body system, condensersystem, deaerater system, bypass system. According to the characteristics ofsupercritical once-through boiler unit, nonlinear lumped parameter moving boundarymethod is adopted to establish the mathematical model of water wall hot watersegment, the evaporator segment and the micro overheating segment. The simulationmachine is used for the simulation experiment of the following cases:10%fuelincreasing under60%MCR,5%load reducing based on60%MCR,5%load reducingbased on100%MCR. The temperature-time curves of the steam from the over heaterand the outlet of the re-heater were drawn. Also the pressure-time curves were given.The comparison between the simulation results and the actual operation conditionsindicates that the higher the load and the smaller the disturbance, the closer thesimulation value and actual value and the smaller the deviation. Despite someproblems, the simulation results can basically reflect the actual operation situation andachieve the expected results.