Experimental thermohydraulic characterisation of flow boiling and condensation in additive manufactured plate-fin heat exchanger

Abstract

In this paper, an experimental thermohydraulic characterisation of flow boiling and condensation in additive manufactured plate-fin heat exchanger was conducted. An original experimental setup was developed allowing the operation of the heat exchanger in both boiling and condensation modes. This heat exchanger mainly consists of two identical rectangular cross-section channels, each of hydraulic diameter 3 mm, with n-pentane and water used as refrigerant and heat transfer fluid, respectively. An experimental metrology, based on the infrared thermography, was implemented in order to determine the temperature distribution of the heat exchanger external walls. Based on this temperature distribution, the mean temperature profiles of the n-pentane and water were determined, allowing the identification of three main flow zones: the subcooled liquid zone, the two-phase (boiling/condensation) zone and the superheated vapour zone. These mean temperature profiles were then coupled to a developed thermal model in order to determine the local thermal parameters, such as heat flux, vapour quality and heat transfer coefficient. The total pressure drop in the two-phase zone was finally determined. All the obtained results were analysed and compared with data available in the literature.