Experimental study of boiling characteristics of plate heat exchanger under sloshing scenarios

Abstract

Aiming to explore the boiling heat transfer characteristics in plate heat exchanger under ocean sloshing scenarios, a two-phase flow boiling experimental system integrated with visualized plate heat exchanger and three degree-of-freedom (DOF) motion platform is designed and built. With special focuses on two-phase flow pattern, temperature and pressure responses, the sloshing effect on flow behaviors and boiling characteristics of plate heat exchanger under different driven modes (pump-driven and self-driven), liquid filled charge ratio, mass flux, sloshing postures (inclined state and swing state) and sloshing orientation (frontal and lateral) are investigated. The results indicate that when plate heat exchanger is fully filled with working fluid under pump-driven mode, the heat transfer efficiency is insensitive to sloshing effect regardless of inclined state or swing state. When plate heat exchanger is not fully filled with working fluid under self-driven mode, the inclined angle poses a great influence on the heat transfer performance by changing the liquid-vapor distribution, with heat transfer coefficient variations of 44 % and 15 % at mass flux of 10 kg/(m²·s) during frontal inclined angle of ±20° and lateral inclined angle of ±20°, respectively. Moreover, there are heat flux variations of 24 % and 177 % at mass flux of 10 kg/(m²·s) during ±20° frontal incline and lateral incline, respectively. For swing state, heat transfer performances are apparently enhanced with the effect of inertial force, characterized by the increases of heat transfer coefficient, heat flux and pressure fluctuation with increasing swing amplitude. Under ocean sloshing scenarios, the operation of plate heat exchanger under high liquid filled charge ratio and mass flux is conducive to eliminate the sloshing effect on flow boiling.