1. During normal pressure of boiler, the oxygen content of flue gas generally is controlled to be around 4-6%.According to the change of oxygen content indicated by  oxygen content meter, quickly judge and adjust the operation of boiler. 

2. If the oxygen indication becomes small, which indicates that the coal many increase or the coal quality suddenly becomes better, or the primary and the secondary air amount becomes less, the coal amount or air amount shall be adjusted immediately  in order to stabilize the parameters of bed temperature. 

3. The increasing of oxygen content shows that the coal amount may be reduced or the coal quality suddenly becomes poor, or the primary air or secondary air amount increases and air leaks from the boiler, measures shall be taken timely in order to maintain the oxygen content within the normal range. 

4. The basic principles for supplying and adjusting the secondary air are that The primary air is used for adjusting fluidization, boiler  temperature and differential pressure of material layer; the secondary air is used for controlling total air volume. When the boiler load is about 40%, the secondary air shall be supplied. 

5. On the condition that the primary air meets the requirement of fluidization, boiler temperature and the differential pressure of material layer, when the total air volume is deficient (the oxygen content after the superheater shall often prevail , the oxygen content during normal running shall be around 5%), the secondary air can be supplied gradually. With the increasing of boiler load, the secondary air volume increases gradually. When the rated capacity is reached, the ratio of primary air and secondary air is about 60% and 40%. 

6. Control to the minimum operation air amount during  operation: The minimum operation air amount is the low limit air volume to guarantee and limit the low load operation of the  fluidized bed.  If the air volume is too low, the normal fluidization cannot guaranteed, and the time of abnormal fluidizing is longer,  there is a risk of slagging. When the cold boiler ignites, it is not proper to below the lowest operating air volume. 

7. The tightness of boiler combustion system has impact on the  oxygen content of flue gas. When the oxygen content in flue gas increases, or the load of the induced draft fan increases significantly,  it is required to check the tightness of flue at each part, the air preheater and the filter, and to take measures to eliminate air leakage. 

8. During operating, it is required to often pay attention to the observation of the  temperature and resistance of various parts of the boiler,  the flue gas temperature and resistance, if it is not normal, it is required to check whether the abnormal phenomenon is caused by air leakage, too much excess air,  coking, ash-blocking or abnormal combustion, and measures shall be taken to eliminate it. 

9. During operation, it is required to often pay attention to the air leakage of various parts of the boiler, all the fire doors and manholes shall be tightly closed, if air leakage happens, measures should be taken to block it. 10. It is required to periodically conduct boiler air leakage test, once every six months at least.