Thermal performance optimization of heat exchanger with mixed cross-corrugated sinusoidal plate channels

Abstract

• The flow and heat transfer in cross - corrugated plate unit channels are investigated. • Effect of phase shift angles on heat transfer performance of wavy channels are analyzed. • The heat transfer performance of mixed wavy channel is optimal at a phase shift angle of 324°. • For each wavy channel, the heat transfer performance of the lower wall is always greater than that of the upper wall. The thermal performance of heat exchanger with mixed cross-corrugated plate plays a fundamental role in the efficiency of the heat exchanger. Based on RNG k-ε model, the heat transfer characteristics of unit channels of three different mixed cross-corrugated plate heat exchangers (30°-50°, 30°-60°, 30°-70°) under different Reynolds numbers ( Re ) are investigated. The distributions of the average Nusselt number ( Nu ¯ ), friction factor ( f ) and Performance Evaluation Criterion ( PEC) of the three mixed unit wavy channels under different phase shift angles (0°≤θ ≤ 360°) are researched. The results indicate that a vortex area is appeared at the bottom wall. As the Reynolds number increases, the vortex area increases, and the vortex shape of the 30°-70° mixed wavy channel is close to circular. In addition, the heat transfer performance of the lower wall is always greater than that of the upper wall for each channel. Moreover, the optimal heat transfer performance for three mixed wavy channels is obtained at phase shift angle of 324°.