Velocity Profiles between Two Baffles in a Horizontal Circular Tube

Abstract

The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat. The baffles are also an important element inside the heat exchanger. Internal materials influence the flow pattern in the bed. The influence of baffles in the velocity profiles was observed using a three-dimensional particle image velocimetry around baffles in a horizontal circular tube. The velocity of the particles was measured before the baffle and between them in the test tube. Results showed that the velocity vectors near the front baffle flow were parallel to the vertical wall, and then concentrated on the upper opening of the front baffle. The velocity profiles showed a flow circulation in the front and rear baffles. These profiles are related to the Reynolds number(Re) or the flow intensity. The velocity profiles at lower Re number showed a complicated flow mixing to obtain the velocities , concentrating on the lower opening of the rear baffle as front wall. Swirling flow was employed in this study, which was produced using tangential velocities at the inlet. By employing this flow, At the entrance of the front baffle, the velocity vector profiles with swirl were much different from those without swirl. However, velocities between two baffles are not much different from those without swirl.