Comprehensive effects of baffle configuration on the performance of heat exchanger with helical baffles

Graphical abstract: - Highlights: • Flow and thermal performances of six helical baffle heat exchangers are analyzed. • The distribution of h_s in whole shell-side is demonstrated. • The flow characteristics of two connection method of baffles are compared. • The optimal helix angle is analyzed by synergy principle. - Abstract: In this paper, non-continuous helical baffles heat exchangers with different helix angles and different connection methods, i.e. including continuous connection method and middle-overlapped method, between two adjacent sections have been simulated by using commercial software of GAMBIT and FLUENT. To explore the comprehensive effects of helix angles and connection way of baffles on the performance of heat exchangers, three kinds of helix angles (20°, 30°, 40°) were chosen. Six heat exchanger models were established to cover the chosen helix angles and two connection methods. To minimize the influence of unrelated factors on analysis results, same geometrical parameters and thermo-physical conditions were used. Therefore the six models with the same geometrical model were simulated with different volume flow rates. Analysis results showed that: the larger helix angle contributes to lower heat transfer rate and lower pressure drop; among all simulated models, heat exchanger with 40° helix angle have the highest heat transfer coefficient per unit pressure drop. Continuous connection method contributes to small local resistance and pressure drop and it has better performance than middle-overlapped method when consuming same pumping power.