空气预热器壳程流场模拟与振动分析

针对中国石化某分公司空气预热器在实际操作过程中经常产生振动、噪音的情况,利用Fluent1 4.0软件对空气预热器的壳程进行流场模拟和振动分析,分析产生振动的原因并提出解决措施。结果表明,空气预热器壳程管束的背面形成卡门涡流,底部空腔产生两个较大的涡流,当卡门涡流频率与箱体固有频率接近时,空气预热器会产生振动和噪音。结合现场布置及装置实际情况,确定改造方案,即在搪瓷管段沿管束方向增加隔板、底部空腔添加导流板以及烟道系统内部增加"井"字形隔墙。改造后,空气预热器未产生明显的振动和噪音。

FLOW FIELD SIMULATION AND VIBRATION ANALYSIS FOR AIR PREHEATER SHELL SIDE

The air preheater vibration and noise often occurs during operation in a SINOPEC refinery. FLUENT software was used to establish a mathematical model for simulating the flow field of shell side and analyzing the causes of vibration and to propose solutions. The results showed that a kamen vortex exists on the back of the air preheater tube bundle, and there are two large vortices in the bottom cavity. As soon as the vortex frequency is close to the inherent frequency of tube box, vibration and noise occur. The revamping plan was confirmed: increasing clapboard along the direction of the pipes in enamel pipe sectors, adding baffle in the bottom cavity and "well" shaped partition wall in the flue system. After revamping, the vibration and noise no longer occur.