Design And Application Of Control System For Pulverized Coal Heating Boiler

In recent years,with the continuous promotion of the national "green development" policy,the national standard of energy conservation and emission reduction is getting higher and higher.This means that industrial boilers with great energy consumption and high pollutant emissions will face tremendous challenges on energy saving and efficiency improvement,especially industrial boilers with pulverized coal as fuel.In northern China,pulverized coal boiler is one of the common heating equipment in winter,However,the lack of safety,economic efficiency and stability of the pulverized coal heating boiler due to the complexity of technological process of the pulverized coal heating boiler,and the nonlinearity and time delay in control system has to some extent limited its application.Nowadays,under the new situation of increasing demand for energy conservation and environment protection.Combined with mature PLC controller,configuration software,variable frequency control,communication technology and advanced control algorithm,an automatic control system of the pulverized coal heating boiler is designed.The system has great practical significance in improving the reliability and safety of boiler,optimizing control,energy saving and efficiency increasing.Based on the analysis of the main parameters and operating principle of the pulverized coal heating boiler,the hardware configuration and software design are carried out according to the characteristics of the pulverized coal heating boiler,such as complexity of system,multiple control parameters and high economical requirements,and following the principle of simplifying structure and saving cost.Through the application of ABB AC500 series PLC with high flexibility,the control and fault alarm of heating boiler field equipment are realized,and the interlock protection of important objects is achieved according to the strict logical relationship.A friendly user monitoring interface is designed by using SIMATIC WinCC configuration software for the boiler real-time operation status.Especially for the combustion system of the boiler,the advanced control technologies such as frequency conversion control,cascade PID and fuzzy PID are applied to optimize the key parameters such as furnace negative pressure,boiler water supply temperature and flue gas oxygen content,which effectively solves the problems of delayed response and poor stability in the operation of the boiler,and plays a substantial role in improving the thermal efficiency of the pulverized coal heating boiler control system.The final boiler operation debugging and energy efficiency test results show that this pulverized coal heating boiler control system has good operation stability and safety.Compared with other pulverized coal boiler systems,its thermal efficiency exceeds the national industrial boiler thermal efficiency limit by 3.94%,which improves the economy of the pulverized coal boiler system significantly and performs high engineering practical value.