| The system operation of modern power plant through many types of sensors to monitor various parameters and variables used to achieve control of the operation. The combustion process of boiler is a typical thermo dynamic process of multi-variable, strong coupling, big-inertia, big-lag and parameters slow changing. For some of the essential measurement and testing equipment, there is a lag measurements, the measurement accuracy problem is not high, which seriously affect the control system performance.Firstly, this paper analyzes the structure and boiler works. In accordance with the parameters of the relationship maps, the combustion control system is divided into the main steam pressure control system, oxy-coal ratio control system and the negative pressure control systems, respectively, is introduced. Analyzed the economic impact of the boiler combustion and gives a major factor in calculating the thermal efficiency of boilers commonly used standards.Secondly, microwave online measurement system is widely used nowadays, however, practically smoke density and velocity have significant influence to the measurement accuracy and it lead great fluctuation of measurement results. In this paper, measurement method of smoke density and velocity is designed and the measurement system based on multi-sensor data fusion technique is structured. BP neural network is utilized to fuse the multi-sensor information effectively. This method have improved measurement accuracy of unburned carbon content in fly ash at a certain extent.Finally, through gathering operating parameters, such as flue gas temperature ,oxygen content, we present a boiler efficiency online calculating model according to redirect heat balance method. An example illustrates this method can meet the engineering needs.
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