| In the automatic control field of modern utility boiler, the main aim is to make its combustion stable and efficient as well as reducing its pollution, and improve the unit's economical efficiency. In the traditional control methods, we mainly use the pulverized fuel amount as input to establish the model of the unit, but if we use this model to control the load of the unit, it could not reflect its dynamic characteristic because of its big lag from it to the power. Although many experts raise some kinds of classical and intelligent control methods, we should find a new controlled variable which could thoroughly reduce the time delay in this process and improve the performance. Current research achievements in furnace temperature distribution visualization can provide the practical basis for the inspection and control of the combustion conditions in the furnace. The radiative energy signal could reflect the combustion situation in the furnace rapidly and accurately without the influence of the anthrax. This paper is aimed at a 300MW coal-fired boiler, designing and adjusting the radiative detection equipments, analysing the heat variation got in the waterwall, superheater, reheater, economizer and air preheater while the fuel rate, auxiliary air and tilt angle change individually. The model of the unit is established using jaw opening of the turbine and the radiative energy signal, which reflects the temperature in the furnace rapidly, as reference. Finally, the radiative energy signal fluctuates due to the high frequency impulsive motion of the flames in the furnace, a filter is designed using the stable heat signal as a reference signal. The output of the filter has the rapidity of the radiative energy signal and as well as the stability of the heat signal, and it could make system's performance better. Finally, the summary of the overall work, some advice on further investigation and modified measurements are given. |
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