Abstract:

With the commissioning of large-scale circulating fluidized bed units, it is very difficult to realize the input of the automatic control and automatic generation control (AGC) functions of the fluidized bed unit, due to its large thermal inertia and hysteresis, and the strong coupling between parameters. Through coordinated control strategy optimization of the first domestic 300 MW external circulating fluidized bed unit, the thermal inertia problem is overcome. By keeping the mass balance, energy balance and bed pressure balance, optimization of the coordinated control system improves its response speed to the main steam pressure derivation through controlling the fuel quantity. Optimization of the secondary air flow control on the upper and lower layers improves the combustion efficiency and overcomes the strong coupling between main steam pressure, bed temperature and bed pressure so as to make the unit adapt to the large inertia and nonlinearity produced by the large quantity of bed material in the furnace. The AGC function is eventually put into operation and satisfactory result has been achieved. On the basis of the problem of the final fluidized bed unit into AGC function, and achieved satisfactory results.