Numerical Study of a Shell and Tubes Heat Exchanger: Impact of the Geometrical Change of the Tube Section on the Overall Exchange Coefficient and the Pressure Drop

Abstract

Shell and tube heat exchanger is the most widely used type in industry because of its advantages: solid design, excellent reliability, compact, resistant to fouling fluids, having a very high exchange coefficient...etc. Several studies have highlighted the importance of this configuration. This study consists in the design and the thermo-fluid simulation by COMSOL software of a shell and tube exchanger with two different tubular geometries: i) circular, ii) square, iii) elliptical 90° using segmental baffles at 25% and two working fluids: water-air. The mass flow rates of the two fluids are varied and their influence on the energy performance of the heat exchanger is also examined. The results show that changing the geometry of the tube bundles affects the pressure drop especially on the shell side, the square geometry created a higher pressure drop than the circular tube geometry. A considerable improvement in the overall exchange coefficient was recorded for the exchanger with the circular tube bundle by increasing the fluid velocity.

Keywords

• Shell and tube heat exchanger
• Simulation
• Thermo-fluid
• Circular tubes
• Square tubes
• Elliptical 90°.