Shellside Waterflow-Induced Tube Vibration in Heat Exchanger Configurations With Tube Pitch-to-Diameter Ratio of 1.42

Abstract

The pitch-to-diameter ratio (P /D ) of the tube layout in shell-and-tube heat exchangers is one of the major parameters with which the designer may control heat transfer and pressure drop and facilitate mechanical cleaning. As part of a comprehensive investigation of waterflow-induced tube vibration in an industrial-size research heat exchanger, various configurations characterized by different design parameters, including P /D ratio, had been investigated. To provide a comparison with previous data obtained with P /D = 1.25, this paper presents the results of a study of eight different tube bundle configurations with P /D = 1.42. Four equilaterally spaced tube layout patterns and two baffle edge orientations were investigated. The results indicate that the greater flow area of the P /D = 1.42 configuration increases flow penetration into the bundle, reduces the tube-to-tube vibration coupling and generally provides less well-defined, even though sometimes improved, fluidelastic instability thresholds.