2002 Volume 2 Issue 3 Pages 195-200
Shell and tube heat exchangers are among the most commonly used type of heat exchangers in the power generation, the chemical process, and the air conditioning industries. Shell-side cross-flow in tube bundles have received less attention due to the flow complexity and the measurement difficulty. In this study, the object was aimed to clarify the flow structure by obtaining detail velocity data in the whole flow area crossing the tube bundles with Particle Image Velocimetry (PIV). Experiments were conducted using two types of model of in-line and staggered tube bundle with pitch-to-diameter ratio is 1.50, containing 20 rows of five 15.0mm O.D. tubes in each row. The velocity data at the spacing between tubes was measured successfully by adjusting refraction index of the working fluid to the same one of tube material. The flow features were characterized in different tube bundle configurations. The results show that the flow is separated the vortex area at the back of tubes from main stream in the case of in-line array, while velocity distribution is more uniform by flow mixing in staggered array. And also three representative patterns of vortex were observed in in-line array but only one pattern of vortex was observed in staggered array.