Design And Optimization Of Temperature Control Scheme For Indirect Air Cooling System

Indirect air cooling system has the characteristics of water saving,energy saving and environmental protection.It is the preferred cold end system for thermal power plants in water-deficient areas in China.However,the influence of wind speed on the cooling efficiency of the air cooling system is very serious.When the wind weather comes,the back pressure of the unit is bound to rise,and it is necessary to appropriately close the opening of the radiator louver to reduce the impact of the wind.Indirect air cooling system,the lack of risk prevention control strategy,the shutters automatic adjustment of back pressure target value is set,if not according to the wind speed is given the right target,will lead to the PID controller continuously open instruction,eventually indirect air cooling system will be completely exposed to the wind,so had to drop out of the automatic adjustment in engineering,The operation personnel can not realize automation by manually adjusting the louver opening depending on their experience,which seriously affects the efficient,safe and stable operation of the indirect air cooling system.Therefore,to study and control the influence law of wind speed and to improve the level of automation is a major task faced by power plants with air cooling units.Based on indirect air cooling system of a certain power plant design data and the analysis and research of the field measurement data,discusses the environment temperature,wind speed,wind direction and degree of the blinds open environmental factors affect the performance of air cooling system,environmental factors and indirect air cooling system back pressure,the relationship between the water temperature curve,based on the results of the analysis to design the wind strategy.In this paper,generalized radial basis neural network is used to predict the optimal and minimum back pressure of the indirect air cooling system at different wind speeds.The optimal back pressure is adjusted to the original temperature to automatically adjust the input value of the PID controller,so as to solve the problem that the PID has to switch to manual adjustment because the PID can not adjust the set value and the optimal value in windy weather.A new control strategy was designed,and the sector selection logic was adopted.When the wind direction randomly changed between 0°and 360°,the corresponding upwind and leeward segments were selected from 12 sector segments in total,and the PID output value directly acted on the selected sector segments to realize the automatic risk prevention control system function.Solve the problem of incorrect selection of sector segment by power plant operators,improve the level of automation,assist PID to achieve better control effect,make the unit parameters stable at a good level for a long time,reduce energy consumption,and improve the safety and economy of unit operation.