D206 SIMULATION ON AN OPTIMAL COMBUSTION CONTROL STRATEGY FOR 3-D TEMPERATURE DISTRIBUTIONS IN PC-FIRED UTILITY BOILER FURNACES

Abstract

The 3-D temperature distribution in a utility boiler furnace is essential for the safe, economic and clean operation of PC-fired furnaces with multi-burner system. In the past, due to the lack of applicable techniques to monitor the 3-D temperature distributions in furnaces, it is difficult to improve the control quality for the combustion processes. The authors is now establishing a technique to visualize 3-D temperature distributions in PC-fired furnace, which makes it possible to study a new combustion control strategy. In this strategy, the whole height of the furnace is divided into several parts, and the average temperatures, the bias magnitudes of the flame centers in the two axis of the horizontal plane in every part is extracted from the visualization results of the 3-D temperature distributions. A linear model is set up to relate the features of the temperature distributions with the input of the combustion processes, such as the flow rates of fuel and air fed into the furnaces through all the burners. The genetic algorithm is adopted to find the optimal combination of the whole input parameters which ensures to form an optimal 3-D temperature field in the furnace desired for the operation of boiler. Simulation results show that the strategy can soon find the factors causing the temperature distribution apart from the optimal state and give correct adjusting suggestions.