催化裂化装置外取热器取热管的肋片选取

Fin selection of heating pipe of external heat exchanger of FCCU

阐述了催化裂化装置外取热器取热单元肋片的设置数量、型式、最佳肋片型式及各种类型肋片的最佳尺寸,提出了肋片设计的基本思路,为工程设计提供了完整的、可操作的设计方法。指出为了取得好的传热效果,在制造允许情况下,尽可能多设肋片;最佳肋片的截面为凹抛物线型,为加工方便,可考虑三角形肋片;各种形状肋片都有最佳尺寸,介绍了最佳尺寸计算公式;计算出了矩形肋片的最佳厚度为11.3 mm。对各种肋片型式耗材进行了比较:同等操作工况和材料下,最佳凹抛物线肋片所需要的材料质量仅为最佳矩形厚肋片的65%左右,最佳三角形肋片所需要的材料质量为最佳矩形肋片的69%左右,但比凹抛物线肋片多耗6%材料。

The number, type, optimal fin type and the optimal size of fins of heat unit of external heat exchanger of FCCU are described. The basic idea of fin design is put forward, which provides a complete and operable design method for engineering design. It is pointed out that in order to obtain good heat transfer effect, as many fins as possible are set up under the permissible manufacturing conditions;the best cross section of the fins is concave parabola, triangular fins can be considered for the convenience of processing;the fins of various shapes have the best size, and the formula for calculating the optimal size is introduced;the optimal thickness of the rectangular fins is calculated to be 11.3 mm. Comparisons are made among various types of fins consumables: under the same operating conditions and materials, the material mass required for the best concave parabolic fin is only about 65% of that for the best rectangular thick fin;the material mass required for the best triangular fin is about 69% of that for the best rectangular fin, but it consumes 6% more material than concave parabolic fin.