Thermal performance optimization of a bayonet tube heat exchanger

A bayonet tube heat exchanger is typically a pair of concentric tubes, the outer of which has a closed end that creates a clearance pass between the inner and annulus tube. This paper evaluates the impact of key parameters and operating conditions on the performance of a bayonet tube by utilizing computational fluid dynamic approach and Taguchi statistical method. A validated two-dimensional model, that considers conservation of mass, momentum and energy, was employed together with an L25 orthogonal array (OA) of Taguchi matrix of five factors and five level designs to determine the optimum combination of parameters as well as their interactions. The result indicates that pipe total length and length of clearance area play an important role in determining the bayonet tube performance in term of pressure drop and heat transfer. The optimum combination of design and operating parameters were obtained with the objective of maximizing the efficiency and performance of the bayonet tube.