Progress in the numerical analysis of compact heat exchanger surfaces

Abstract

Compact heat exchangers (CHEs) are characterized by a large heat transfer surface area per unit volume of the exchanger, resulting in reduced space, weight, support structure and footprint, energy requirements, and cost, and improved process design, plant layout, and processing conditions, together with low fluid inventory compared to conventional designs such as shell-and-tube heat exchangers. Plate-fin, tube-fin, and rotary regenerators are examples of compact heat exchangers for gas flow on one or both sides; whereas gasketed, welded, brazed plate, and printed circuit heat exchangers are examples of compact heat exchangers for liquid flows. A considerable amount of experimental results are available in the literature for flow and heat transfer phenomena in complex flow passages of compact heat exchanger surfaces. A comprehensive experimental study of the performance of CHE surfaces is very expensive because of the high cost of the tools needed to produce a wide range of geometric variations. Numerical modeling, on the other hand, has the potential of offering a flexible and cost-effective means for such a parametric investigation, with the added advantage of reproducing ideal geometries and boundary conditions, and exploring the performance behavior in specific and critical areas of flow geometry. This chapter provides a comprehensive state-of-the-art review on numerical studies of single-phase velocity and temperature fields, and heat transfer and flow friction characteristics of compact heat exchanger surfaces, and also provides specific comparisons to evaluate the accuracy of numerical work where experimental data are available.