Effect of binary fluid on the heat transfer performance of flat plate micro heat pipe

Abstract

A flat plate micro heat pipe (FMHP) is a passive thermal management device widely used in chip heat dissipation. In this paper, by analyzing the heat transfer principle of FMHP, we found that the heat transfer limit of FMHP is positively related to the latent heat of evaporation of the working medium, and the methanol binary fluid containing deionized water can increase the latent heat of the working medium. Therefore, four heat pipes with different concentrations of binary fluids of methanol and deionized water as the FMHP work medium and pure methanol as the working medium was fabricated, and a platform was built to test the five heat pipes. The results show that the 80% methanol content in binary fluid flat plate micro heat pipe(BF80-FMHP) has the maximum thermal power and exhibits better heat transfer characteristics than the 100% methanol content in binary fluid flat plate micro heat pipe (MF100-FMHP), with a 12.0% increase in maximum thermal power and a 15.1% decrease in dynamic response time. The 60% methanol content in binary fluid flat plate micro heat pipe(BF60-FMHP) has the fastest dynamic response time, 30.42% lower than the MF100-FMHP, but the maximum thermal power is 10.0 W lower than that of the MF100-FMHP. The proper concentration of binary fluid can effectively increase the maximum thermal power of FMHP, increase the working range, improve the heat transfer capability of FMHP at high temperatures, and enhance the dynamic response time at high power.