Description:
<jats:p>The characteristics of two-phase flow boiling of R-290 are required for replacing R-22 that has been phased-out. The present study focuses on experimental pressure drop for R-22 and R-290. The experiment was run with heat flux of 5.09 kW/m<jats:sup>2</jats:sup> to 19.03 kW/m<jats:sup>2</jats:sup>, mass flux of 114.91 kg/m<jats:sup>2</jats:sup>s to 751.74 kg/m<jats:sup>2</jats:sup>s and saturation temperature of 4.77°C to 18.12°C. The present result showed that pressure drop was affected by heat flux, mass flux and saturation temperature. Lower mass flux, heat flux and saturation temperature results in lower pressure drop. The pressure drop of R-290 is lower than that of R-22. Among the existing pressure drop prediction methods, Lokhart-Martinelli (1949) gives the best prediction for the present pressure drop data.</jats:p>