300MW机组循环流化床锅炉回转式空气预热器漏风率偏大的原因及对策

CAUSE AND COUNTERMEASURES FOR HIGHER AIR-LEAKAGE RATE OF THE ROTARY AIR PREHEATER USED FOR CFB BOILER OF 300 MW UNIT

300MW机组循环流化床锅炉回转式空气预热器存在漏风问题,分析认为径向和轴向密封片严重磨损、旁路密封片大量损坏、转子顶部及底部T型钢圆度误差偏大等是造成漏风的主要原因。对此,提出了控制空气侧与烟气侧压差,以及控制径向、轴向和旁路密封间隙等措施。实施后,空气预热器漏风率约减少了3.3%。

The problem of air - leakage was existing in the rotary air preheater of circulating fluidized bed （CFB） boiler used for a 300 MW unit. It is believed from analysis that the main causes resulting in air leakage are as follows： severe wornout of radial and axial sealing strips, damage of large amount in by- pass sealing strips, large roundness error of T- shaped steel at top and bottom of the rotor etc. For these, measures, such as controlling the pressure difference at the air side and the rue gas side, and controlling the clearance of radial, axial, and by- pass sealings, etc, have been put forward. After implementation, the air leakage rate of said air preheater has decreased about 3.3 %.