大型动力锅炉机组发生故障的原因,是高压和低压蒸汽过热器在不加热出口区段蛇形管与联箱的焊接结合点处遭损坏。蛇形管与联箱焊接结合点损坏的原因多半是,由于过高的温度和来自固定工况中内压应力,以及启动和停炉时循环温差应力和补偿应力的影响,而使金属管子的 The reason for the failure of a large power boiler unit is that high pressure and low pressure steam superheaters are damaged at the weld joint of the serpentine tube and header without heating the exit section. Most of the causes of damage to the joint between the serpentine tube and the header are due to the over-temperature and the internal pressure stress from a fixed condition, as well as the effects of the cyclic temperature difference stress and the compensating stress on start-up and shutdown,