Pool boiling heat transfer enhancement by using metal foam enhanced surfaces

Abstract

In general, this project deals with the theoretical and experimental study of pool boiling by using metallic and non-metallic foams on plain copper surfaces as heating surface. This research involves the design of an experimental apparatus and the results analysis, including the phenomenon visualization. The aim of this study is to analyze the influence of different foams and their characteristics on the heat transfer coefficient, such as material type, porous density, porosity and thickness. The tests will be performed using HFE7100 as working fluid (at atmospheric pressure and at saturation temperature), and the metallic and non-metallic foams will be added to the plain copper by using tin welding. Aspects concerning surface-fluid interaction will be thoroughly studied by analysis of the experimental data and visualization of the boiling phenomenon by using a high speed camera (to study the vapor bubble dynamic). This study will also involve the characterization of the surfaces tested, through the techniques of scanning electron microscopy (SEM) and wettability test. The contribution of this work is to obtain results of interest to the industry for new refrigeration system components, air conditioning and cooling of electronic components for thermal control of machines, where the heat fluxes to be removed are higher than those provided by single-phase systems. In addition, the results will contribute to the knowledge on the pool boiling mechanisms that enhance/deteriorate the heat transfer coefficient on enhanced surfaces, including the development a semi empirical model.