A Comprehensive Experimental Investigation of Additives to Enhance Pool Boiling Heat Transfer of a Non-Azeotropic Mixture

Abstract

Adding nanoparticles or surfactants to pure working fluid is a common and effective method to improve the heat transfer performance of pool boiling. The objective of this research is to determine whether additives have the same efficient impact on heat transfer enhancement of the non-azeotropic mixture. In this paper, Ethylene Glycol/Deionized Water (EG/DW) was selected as the representing non-azeotropic mixture, and a comparative experiment was carried out between it and the pure working fluid. In addition, the effects of different concentrations of additives on the pool boiling heat transfer performance under different heat fluxes were experimentally studied, including TiO2 nanoparticles with different particle diameters, different kinds of surfactants, and mixtures of nanofluids and surfactants. The experimental results showed that the nanoparticles deteriorated the heat transfer of the EG/DW solution, while the surfactant enhanced the heat transfer of the solution when the concentration closed to a critical mass fraction (CMC). However, the improvement effect was unsteady with the increase in the heat flux density. The experimental results suggest that the mass transfer resistance of the non-azeotropic mixture is the most important factor in affecting heat transfer enhancement. Solutions with 20 nm TiO2 obtained a steady optimum heat transfer improvement by adding surfactants.

Application of Refrigerant Cooling in a Battery Thermal Management System under High Temperature Conditions: A Review

“…Non-azeotropic mixed refrigerants are refrigerants composed of two or more substances that do not meet the condition of a coexisting saturated vapor and saturated liquid. The boiling point of the mixture changes with the proportion of its components, and therefore, it is also referred to as an “incompatible mixture” .…”

Investigation of Heat Transfer Performance in Deionized Water–Ethylene Glycol Binary Mixtures during Nucleate Pool Boiling

“…Although the Rohsenow correlation is based on bubble agitation theory, this part is simplified as a fixed empirical constant during calculation, and the convective effect generated by bubble agitation is not the main contribution to heat transfer during pool boiling. Therefore, on this basis, Mikic and Rohsenow reconsidered the impact of bubble dynamics on boiling performance and modified the model with the nuclear bubble diameter parameter [24], as shown in Equations ( 12)- (14).…”

“…To address these issues, mixed refrigerants are being recognized as a potent alternative to conventional working fluids. These mixtures not only help in reducing the GWP but also capitalize on the benefits derived from each individual component [14]. A key advantage of mixtures lies in their tunable chemical and thermophysical properties.…”