CH-03-13-3 -- Evaluation of Existing Evaporative Heat-Transfer Models in Horizontal Microfin Tubes PDF

Three evaporative heat-transfer models for microfin tubes are reviewed in this paper. Different approaches have been used to develop the two-phase heat-transfer models. One model was reviewed but was not considered for reproduction, as the fluid-dependent parameter in the model limits the general use of the correlation. The heat-transfer coefficients predicted by the other three models are compared to 371 experimental data points for pure refrigerant. The models were reproduced to predict the evaporative heat-transfer coefficients. One of the three models displayed poor overall prediction on all of the pure refrigerant data used for its validation. This model also had several parametric and geometric limitations, which made it inapplicable to certain heat-transfer environments. In general, the other two models exhibited good predictive capabilities for pure refrigerant and were applicable to a wide range of flow conditions. However, both models overpredicted the R-134a data.

Units: SI