Experimental Study on Condensation Coefficient of Room-Temperature Phase Transition Fluid in Horizontal Microchannel Array

The self-circulating evaporative cooling technology, utilizing latent heat, was developed to address the thermal dissipation challenges in power electronics with high heat flux. To meet miniaturization demands, the condenser was designed with microchannel structures. Six different microchannel specifications were fabricated, and condensation coefficients were measured for 108 cases on the dedicated microchannel experiment platform. The experimental data were analyzed, and the results were compared with representative existing empirical correlations. A new adapted correlation for the condensation coefficient is proposed, incorporating the Jacob number. This new correlation improved the prediction error to within the range of $\mathbf{- 3 0 \%}$ to $\mathbf{+ 3 5 \%}$. Additional experiments were conducted to further validate the proposed correlation, extending its applicability to room-temperature phase transition fluid mass fluxes ranging from 130 to $\mathbf{3 6 0} \mathbf{~ k g} / \mathrm{m}^{2} \mathrm{~s}$ and hydraulic diameters between 0.5 mm and 1.0 mm.