Research on soft-measuring method of unmeasurable input for Cycle Fluid Bed Boiler (CFBB)

The algorithm of online soft-measuring method was researched for the system that was described by nonlinear dynamic model. Firstly, the online solving method of the adaptive particle swarm optimization (APSO) algorithm and the closed loop PID controller algorithm were discussed. Then the unmeasurable input (the quality of the coal) of the Cycle Fluid Bed Boiler (CFBB) was measured by the two methods based on its dynamic burning model and the industrial operation data. The accuracy of measurement and the time of calculation were satisfied for the online application by the research results. But more calculation time was required for the method of APSO because several iterations were needed for its optimization object. On the contrary, more accuracy measuring results and less calculation time were obtained by the closed loop PID controller method. In addition, the closed loop PID controller method was more stable than the method of APSO by its application.