固定管板换热器膨胀节设计应注意的几个问题

PROBLEMS NEED ATTENTION IN THE DESIGN OF EXPANSION JOINT OF FIXED TUBE SHEET HEAT EXCHANGER

介绍了固定管板换热器设计中与膨胀节的设置相关的几个问题,包括膨胀节设置原理:因管程与壳程的膨胀系数不同致使两者的膨胀差过大,导致壳程筒体拉伸应力、换热管拉伸或压缩应力、换热管拉脱力中出现的不合格项,需要设置膨胀节。介绍了膨胀节与筒体对焊连接时,允许筒体削薄的限制条件,包括膨胀节设置位置的确定:对于立式换热器,膨胀节宜设置于耳式支座的下方;而卧式换热器应设置于管道约束小的一侧等等。

This paper introduces several items related to the setting of expansion joint in the design of fixed tube sheet heat exchanger, including the explanation of the setting principle of expansion joint, i.e. the different expansion coefficients of the tube and the shell leads to overhigh differential expansion, resulting in non-conforming shell tube tensile stress, heat exchange tube tensile or compression stress, and heat exchange tube pulling force, so expansion joint needs to be set. The limiting conditions of allowing the thinning of tube body when the expansion joint is connected with the tube body by butt welding are introduced. Also the determination of the setting position of expansion joint is discussed. For vertical heat exchangers, the expansion joint is preferably set below the lug support, while for horizontal heat exchangers, it is preferably set on the side with less constraint of pipeline.