The applicability of the electrohydrodynamic (EHD) technique for convective boiling heat transfer of R404A (an azeotropic refrigerant mixture consisting of 44% R125, 52% R143a, and 4% R134a) was addressed experimentally. Experiments were performed as a function of parametric values of electrical field potential, average vapour quality in the test section, heat flux, and the mass flux. All experiments were performed in a 0.5-in. commercially available microfin tube. It is demonstrated that R404A responds favourably to the EHD effect, yielding nearly a fourfold increase in the heat transfer coefficients in the present experiments with negligible EHD electrical power consumption.

KEYWORDS: year 1996, refrigerants, mixtures, R404A, experiment, heat flow, azeotropic, R125, R143a, R134a, tubes, heat transfer coefficient, electricity consumption, calculating, performance, laboratory testing