FLOW BOILING HEAT TRANSFER AND TWO-PHASE PRESSURE DROP OF ISOBUTANE IN A 1.1 MM DIAMETER TUBE.

Daniel Felipe Sempértegui-Tapia¹; Gherhardt Ribatski¹

¹ EESC - USP

doi:10.20906/CPS/COB-2015-2745

Resumo

In the present paper, two-phase pressure drop and flow boiling heat transfer results of isobutane (R600a) in a circular channel with an internal diameter of 1.1 mm are presented. Experiments were performed for mass velocities ranging from 100 to 500 kg/m²s, heat fluxes up to 145 kW/m², saturation temperatures of 31 and 41°C, and vapor qualities from 0.05 to 0.91. The experimental data are carefully analyzed and discussed. Subsequently, the experimental data were compared against predictive methods from literature. For pressure drop, the methods by Sempértegui-Tapia and Ribatski (2016) and Del Col et al. (2013) provided accurate predictions of the results. For heat transfer coefficient, the methods of Kanizawa et al. (2015) and Liu and Winterton (1991) provided the best predictions. However, both methods mostly underpredicted the experimental data characterized by the predominance of convective effects.

Palavras-chave: flow boiling; pressure drop; microchannel; isobutane