Better Thermal Calculations Using Modified Generalized Leveque Equations for Chevron Plate Heat Exchangers

Abstract

Plate heat exchangers are becoming vital process energy exchange equipment in chemical industries. The present work looks into the applicability of the Generalized Leveque Equation (GLE), which is used to generate thermal performance calculations for chevron-type plates utilized in plate and frame heat exchangers. New Modified Generalized Leveque Equations are proposed to improve calculation accuracy, which will enhance energy utilization and cost reduction in the design stage. A case study was selected to examine the GLE applicability when implemented to pure and mixed chevron plates. The GLE and other modified equations are compared with known classical correlations for different corrugation angles of 30°, 45°, 50°, 60° and 65° as pure chevron plates, and 45°/90°, 23°/90°, 45°/45°, 23°/45°, and 23°/23° as mixed chevron plates. Both the GLE and single Modified Generalized Leveque Equation (MGLE) gave good results only for 30° and 50° pure chevron angles and failed to give acceptable results in 45°, 60° and 65° chevron angles; both, however, gave acceptable results with all tested mixed angles. Also, the GLE has the tendency to be more applicable in the laminar region where Re < 2100, but the inaccuracy increases when applied in the turbulent region, while MGLE gave slightly lower relative error at high Re. Based on the classification of soft and hard chevron plates, two new Modified Generalized Leveque Equations, MGLE(1) and MGLE(2), were developed from the set of Kumar's data for pure chevron plates. The proposed system of equations are capable of providing excellent results for both pure and mixed chevron angles when compared with a large set of classical correlations available in the literature.