Experimental investigation on heat transfer characteristics of two-phase flow boiling in offset strip fin channels of plate-fin heat exchangers

摘要

To optimize the plate-fin heat exchangers in the cryogenic processing system, the heat transfer characteristics of two-phase flow boiling for high-efficiency and pressure-resistant offset strip fins in plate-fin heat exchangers were investigated experimentally. The experimental conditions cover heat fluxes of 0.7-5.5 kW/m(2), mass fluxes of 64-128 kg/(m(2).s) and vapor qualities of 0.1-1.0. The research results show that, as the vapor quality increases, the heat transfer coefficient initially increases and then decreases, representing a maximum at vapor quality of 0.75-0.85; the critical conditions of the bubbly-annular transformation and the annular-mist transformation are corresponding to the void fractions of 0.92 and 0.985, respectively. A new correlation of two-phase heat transfer coefficient for flow boiling in offset strip fin channels was developed based on the experimental data in the present study and in the literature, and the prediction deviation is within +/- 25%.