Average Nusselt numbers were measured for R22, R290, R290/600a, and R32/152a undergoing evaporation and condensation in a brazed plate heat exchanger. The refrigerants experienced wavy, stratified flow at low heat and mass fluxes, 1.3 kW/m2 to 8.3 kW/m2 and 1.6 kg/m2 s to 19 kg/m 2 s, respectively. Heat transfer correlations from the literature for in-tube and channel flow of refrigerants with ...

Per Lundqvist Dr., Lars Herbe M.Sc, The Royal Institute ofTechnology, Dept. of Energy Technology, S-100 44, Stockholm, Sweden Fax: +46 8 20 30 07 Tel: +46 8 790 74 52 Email: [email protected] There are several important issues when dealing with new refrigerants in a retrofit situation. This paper is however restricted to system performance and a discussion of methods suitable to determine ...

Madeleine R. Johnson AGMC/MAEL 813 Irving Wick Drive West Newark AFB, Ohio 43057-5149 This paper describes the initial results of a refrigerant retrofit project at the Aerospace Guidance and Metrology Center (AGMC) at Newark Air Force Base, Ohio. The objective is to convert selected types of test equipment to properly operate on hydrofluorocarbon (HFC) alternative refrigerants, having no ozone ...

This paper demonstrates the capabilities of the PFGC-MES equation of state (EOS) for calculating the thermodynamic properties in the superheated region for pure refrigerants. In addition the ability of this EOS is also tested for predicting the VLE behavior of binary mixtures. For pure compounds several properties in the superheated region are predicted. The calculated results and the experimen...

The examination of available vapor pressure data in the case of the methane, ethane, propane and butane halogenated refrigerants, allowed recommendations of standard equations for this property. In this study, three new models include a general correlation; a substance-dependent correlation and an artificial neural network (ANN) approach have been developed to estimate the saturated vapor press...

REFPROP: A Thermodynamic Properties Software Pro gram for Refrigerants and Their Mixtures

Due to the increased public concern over the role that chlorofluorocarbons CCFCs) play in depleting stratospheric ozone, a landmark international agreement , the Montreal Protocol, was signed in 1987 which regulated the production and consum ption of CFCs. More recently, several nations, most notably Canada, the Federal Rep ublic of Germany, Norway, Sweden, and the United States, have planned o...

The present work is the successful extension of an improved equation of state (EOS) to refrigerant fluids. The objective is the prediction of isothermal and saturated liquid densities of refrigerants. Two temperature-independent parameters appearing in the modified EOS are closely related to critical point properties of refrigerant fluids. Our results showed that, the proposed EOS can predict w...

This research is aimed to define , (1) the effects of refrigerant to the environment, (2) derive the eco friendly refrigerants by using software REFPROP, (3) describe the properties of refrigerant by mixing them in appropriate percentage, (4) reducing GWP and ODP by providing suitable substitute of CFC’s and HCFC’s refrigerants, (5) reducing the effect of refrigerant to the ODP. This analysis i...