浅析热冲击对自增强反应器的影响

自增强反应器在服役期间，其残余应力会因开停车循环载荷作用，温度、压力的波动及管内介质发生超温分解反应引起的热冲击等因素的作用而衰减，为了比较系统地探讨热冲击引起的自增强残余应力衰减机理和管材损伤机理，本从研究管式反应器受热冲击作用时的应力响应出发，建立相应数学模型，得到了应力随时间变化曲线，应力随半径变化曲线，通过分析得出了热冲击发生时产生的动态应力和异常高温是引起残余应力松弛和材质发生相变和老化的主要原因。

AN ANALYSIS ON THE INFLUENCE OF HEAT IMPULSION ON AN AUTOFRETTAGED TUBULAR REACTOR

This paper is focused on a brief analysis and discussion of the decompose reaction that may take place at extremely high temperatures due to the heat impulsion. As is well known, in order to engender residual stress along the wall thickness from the inside to the outside, it is necessary to increase the capacity of elastic lorry of an tubular reactor, which has to be subject to a certain autofrettage. As a result of impulsion, autofrettage may appear in conformity with the manufacturer's standard at a depth of 20%-30% of the wall thickness proceeding from the inside to outside. But the residual stress will be attenuated during the tubular reactor operating, the reasons for attenuation can be many, such as the impact produced as a can or lorry abruptly starts to move or bring to a sudden halt, a great pressure or temperature fluctuation would lead to the motion of the impulse valves, which may result in an ultra-heat decompose reaction and so on. Based on our research on the stress reaction of the tubular reactor that is subject to heat impulsion,we have done a careful analysis of the mechanism of the attenuation of residual stress and damage, bringing about a curve table to reduce the heat impulsion damage. Our analysis indicates that heat impulsion is the primary factor that causes the attenuation of the residual stress. To be exact, with the increase of the heat, the attenuation-rate of the residual stress of autofrettage would increase 5.8%. Therefore, the worker working at the control console should keep monitoring the change of temperature during the day time to improve his maintenance and constantly check the attenuation-rate according to the regulations established.