Numerical Investigation and Thermodynamic Analysis on a Novel Regular Hexagonal Plate Heat Exchanger

In conventional Plate Heat Exchangers (PHEs), a good heat transfer performance is usually obtained at the cost of much pumping power consumption. In order to address this dilemma, a novel Regular Hexagonal Plate Heat Exchanger (RHPHE) is proposed in this paper. Specially-shaped spherical ribs and quasi-spiral flow paths are designed on plates with the purpose of achieving a best trade-off between the heat transfer and fluid flow performance. Because of its regular hexagonal structure with 3 inlets and 3 outlets, three or at least two kinds of fluids with different temperatures can exchange heat in a single set of heat exchanger. It is an innovation that multiple fluids heat transfer in a PHE without the assistance of supplementary baffles. Numerical investigation is carried out on the RHPHE and water is the working fluid. The heat transfer and flow performance of the RHPHE in a series of working conditions are investigated. Results show that heat transfer coefficient per unit pressure drop of the RHPHE is much better than that of the widely accepted PHE with 60° chevron corrugations. Also studied is the influence of various combinations of inlet and outlet positions on heat transfer and fluid flow performance. For the thermodynamic analysis, the entropy generation caused by heat conduction under finite temperature difference and fluid friction is obtained numerically. The variation of the entropy generation number with respect to the Reynolds number is depicted, which provides reference for the future optimization design of the RHPHE.