--- As the CFB boiler lining adopts a lot of wear-resistant refractory material, especially the lining of the back-feeding leg of separator, the back-feeding valve and the outlet flue, the start-up speed of the CFB boiler is limited by the temperature-risen rate which is required by the lining. The change speed of smoke temperature is the key factor of the generation of thermal shock. The reasonable starting method can ensure the thermal stress of the lining would not be too excessive. Normally the allowed maximum temperature changing rate of the refractory material manufacturer is ±100℃/h, therefore, make sure that the temperature change would not exceed 100℃/h during the operation period.
--- In the starting time, both the lowest primary air flow required by the bed material fluidization and the air distribution of the burner would lead to the result that the boiler operates under the excessive air coefficient which is relatively high.
--- The two sets of under-bed ignition burner flow is 350Kg/h, the operating oil pressure is 2.0MPa. The under-bed ignition combustion rate is about 12% of the total combustion rate. When the bed temperature is maintained to be above of the allowed feed temperature (for the bituminous coal, it is about 450℃), feed the first feeder under the slowest speed. Whether the coal is fired or not can be determined according to the temperature changing rate of bed temperature. Then other feeders should be operated to increase the combustion rate.