Water wall tube in high temperature area in the DC boiler of 600 MW unit of a power plant is leaking due to transverse cracks.Through inspection and analysis,it is concluded that the thermal fatigue stress of the water wall pipe in the high temperature area is caused by abnormal wall temperature fluctuation.Coupled with the operation of the pipe wall in a sulfur-containing corrosive atmosphere,under the joint action of the thermal fatigue stress and sulfur corrosive atmosphere,the dense distribution of corrosive thermal fatigue cracks are formed in the boiler water wall pipe towards the fire side wall,and the cracks spread through the pipe wall,leading to the leakage of the water wall pipe at this position.In view of the corrosive thermal fatigue crack of water-cooled wall pipe,the corresponding prevention measures are put forward.
维普
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