Critical heat flux experimental evaluation of micro-heat exchanger

• Grant number: 13/25086-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2014
• End date: February 28, 2015
• Field of knowledge: Engineering - Mechanical Engineering - Thermal Engineering
• Principal Investigator: Cristiano Bigonha Tibirica
• Grantee: Luiz Eduardo Czelusniak
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

This research is part of several projects involving heat transfer in compact heat exchangers being performed by the Heat and Mass Transfer Group of the Mechanical Engineering Department of São Carlos - USP. The critical heat flux (CHF) is the maximum heat flux that a heat exchanger can operate without burning during flow boiling. Given its importance to safety in critical systems, it is the theme of intensive experimental research, aiming the development of correlations for prediction of critical heat flux. In the last 6 years, the advisor of this project, has been researching critical heat flux during flow boiling in micro-scale channels, building a extensive experimental data bank for halogen fluids (R134-1,R245fa,R1234ze) for refrigeration applications in micro electronics and air conditioner. New correlations were also developed from these works. In this context, with the objective of expanding the experimental data bank to micro exchangers applications where water is the operating fluid, this research proposes new experimental campaign for CHF during water flow boiling in horizontal micro-scale heat exchanger, both using a single channel and a mini heat exchanger. These results will have great importance to validation of correlations to predict CHF and also to assist the development of applications where water is the heat transfer fluid, given that water is one of the fluids that allow higher heat exchange during convection, with low cost and low enviromental impact.