Abstract
This paper presents a prediction method for evaporating heat transfer coeffcient of refrigerants fowing in a horizontal spirally grooved tube with consideration of flow regimes. The experimental data employed for development of the correlation equation were measured at pressures 0.2-1.1 MPa, mass velocities 100-300kg/(m2s), heat fluxes5-25 kW/m2 and vapor qualities 0.1-0.8 with HCFC123 and HCFC22 using a spirally grooved steel tube with 12mm in average inner diameter, 32 in number of groove, 0.4 mm in depth of groove and 15 degree in helix angle. In the previous paper, the authors showed that the flow patterns of evaporating refrigerant inside a horizontal spirally grooved tube could be classified into four types : annular flow, annular flow with liquid meniscus, separated flow with liquid meniscus and separated flow with dry surface, and proposed the correlations for the borders of each flow regime. In the present paper the correlation equations for heat transfer coeffcient were developed for each flow regime. The calculated heat transfer coefficient showed good agreement with the experimental data for all flow regimes. The mean deviation between the calculated and the measured heat transfer coefficient is ±12.6% for the all present experimental data.
