Abstract:

The load-rejection test of a 705 t/h CFB(circulating fluidized bed) boiler is introduced in this paper. Considering the large thermal inertia of CFB boiler, the combustion and the bed temperature could been maintained in normal operation conditions by adjusting the coal feeding and the primary/secondary air flow. The parameter control methods of steam temperature and pressure are also discussed. During the period of load rejection, the parameters of bed temperature, differential pressure of furnace, the steam temperature and pressure are analyzed systematically, as a result that the unit could be synchronized and reloaded rapidly after load-rejection, and the test costs and recovery time distinctly decrease. The experiences can provide references for the load-rejection and quick load change of the same type unit.