Correlation of Evaporative Heat Transfer Coefficients for Refrigerant Mixtures

摘要: On the basis of measured evaporative heat transfer coefficients for pure refrigerants (R22, R32, Rl25, Rl34a, R290, and R600a) refrigerant mixtures (R32/R134a R290/R600a) in a horizontal tube, correlation is developed. An analysis performed an annular flow mixtures. Mass effect due to composition difference between liquid vapor phases, which considered as driving force mass at interface, included this analysis. Correction factor CF introduced The are calculated using considering nucleate boiling low quality region zeotropic INTRODUCTION New alternative production application techniques being As higher efficiency system constantly required, new technique performance enhancement pursued use thought be solution. Some show temperature glide during evaporation condensation (i.e., zeotrope), can utilized reduce mean secondary fluid refrigerant, known increase cycle from basic principles thermodynamics. It has been by many researchers that coefficient (HTC) smaller than linearly interpolated HTC based on those constitutive refrigerants. This phenomenon attributed non-linear behavior thermodynamic properties caused change mixtures.< 1 · 4 l For mixtures, resistance obtained regression experimental data. However, since determined data, such correlations becomes limited when they applied other fluids. Therefore, simple physically meaningful used fluids required. Furthermore, it desired In study, predict HTCs will presented. To consider different characteristics phases introduced. Correlations data compared. EXPERIMENTS Test Review Data Reduction flowing tube have