Experimental study on flow boiling heat transfer characteristics of multi-channel modified filled foam metal small channel

Abstract

This experiment reports the experimental study on the heat transfer performance of water in the flow-boiling heat transfer process of different modified foam metal-filled channels. In the experiment, the foam metal has subjected to surface hydrophobicity treatment, surface roughness modification treatment, and gradient pore density stacking treatment. The mass flow rate is 50–150 ml/min, and the heat flux is 15 kW/m2 – 25 kW/m2. The pore density of foam metal is 20 PPI, 50 PPI, and 110 PPI. A high-speed camera, micro camera, and electron microscope are used to record and observe the internal flow of the channel, the results after surface treatment, and the related reaction mechanism. The experiment uses different modifications as the basis for grouping and uses heat flux and mass flow rate as variables to perform multiple sets of orthogonal experiments. At the same time, the prediction model of matching heat transfer coefficient and the correlation of pressure drop gradient are proposed. Construct a comprehensive evaluation index of heat exchange of porous foam metal, which is evaluating the heat exchange performance of foam metal that matches the change of resistance.