Stress Problems at the Steam Drum Fatigue Checking Point of a Supercharged Boiler

Abstract

On the basis of the proposed computing method for the low-cycle fatigue lifetime of a supercharged boiler steam drum, and the two computing principles, which super-pose the resultant stress of the internal pressure stress and the radial temperature difference heat stress at the boiler steam drum fatigue checking point, whose influences on the low-cycle fatigue lifetimes of one supercharged boiler steam drum were calculated, compared and analyzed, there out the computing principle of a supercharged boiler for superposing the resul-tant stress of the above-mentioned two stresses was opened out. The simplified computing method, which will be applied to calculating the alternating stress range in a stress cycle at the supercharged boiler steam drum fatigue checking point, was also derived from combining the design feature of a super-charged boiler steam drum with theory analysis, and com-paring with the Chinese Standard computing method, this computing method not only can reduce the calculational work-load, but also can simplify the calculational steps greatly. Thereby the proposed computing method for the low-cycle fatigue lifetime of a supercharged boiler steam drum was also further simplified.