锅炉小径管焊口所受载荷性质对其应力集中的影响

INFLUENCE OF LOAD PROPERTY BORNE BY THE WELDED JOINTS OF SMALL DIAMETER TUBES IN BOILERS UPON THEIR STRESS CONCENTRATION

200 MW机组锅炉再热器集箱小径管在运行时所承受的载荷有介质压力、弯矩、轴力、剪力4种类型,通过数值解法计算模型,研究了小径管焊口所受载荷的性质对其应力集中的影响。结果表明,3个被研究的关键点的应力数值以第1点最高;弯矩对最危险点的应力集中的影响最为明显,其次是剪力、轴力和介质压力。

There are four types of load, namely medium pressure, bending moment, axial force, and shearing force, acting on small diameter tubes in the reheater＇s header of boiler equiped for 200 MW units in operation. Through calculation model of numerical solution, the influence of load property borne by the welded joints of small diameter tubes upon their stress concentration has been studied. Resuits show that the values of stress acting on three studied key points are as follows： the highest value is on the first point; the influence of bending moment upon stress concentration at the most dangerous points is most remarkable; and the effect of shearing force, axial force, and medium pressure ranks in the next.