in the present work, the integral equations method is used to calculate transport properties of polar fluids. for this goal, we use the stockmayer potential and examine theoretically the thermal conductivity of several refrigerant mixtures such as r125+r134a, r125+r32, r125+r152a, r134a+r32, r152a+r32, r134a+r143a, and r125+r143a. we solve numerically the ornstein-zernike (oz) equation using th...

four kinds of refrigerant mixtures R22/Rl34a, R22/Rl52a, R22/Rl42b and R22/Rl23, which contain some new halocarbons which are considered to be the alternatives for CFCs, were evaluated in order to realize higher condensing temperature than that using R22 at high temperature operation, and larger heating capacity than that using R22/Rll4 at normal temperature operation. These mixtures were appli...

The present paper summarizes the activities at LTT-Erlangen on the field of thermophysical properties research for pure refrigerants and refrigerant mixtures. For the characterization of their thermophysical properties dynamic light scattering (DLS) has been intensively applied as a key tool during the past two decades. Beside a representation of the essential features of DLS for the determinat...

This paper investigates the feasibility of hydrocarbon refrigerant mixtures as a replacement for HCFC-22 in residential air-conditioning and heat pump systems. The COP and the seasonal performance factor (SPF) were calculated using a UA-model for single component refrigerants and refrigerant mixtures. Simulations were run for pure propane and the mixtures of propane/i-pentane, propane/n-butane,...

The condensation heat transfer characteristics of nonazeotropic mixtures R1234yf and R32 (mass fractions of 0.52:0.48 and 0.77:0.23, respectively) inside a horizontal smooth tube (inner diameter 4 mm) were experimentally studied at mass fluxes ranging from 100 to 300 kg/m s. A prediction model for the forced convective condensation heat transfer characteristics of nonazeotropic refrigerant mixt...

This chapter provides the engineer and the researcher with correlations and models for the prediction of the critical aspects of the boiling heat transfer of mixtures. This chapter offers a reliable, hands-on resource for solving common problems across pool boiling and flow boiling applications such as miscible mixtures, refrigerant/lubricant mixtures, additives, and refrigerant/nanolubricants....

In this work, the inversion scheme was used to determine the potential energy surfaces of five polar refrigerant mixtures. The systems studied here are R123-R134a, R123-R142b, R123-R152a, R142b-R134a, and R142b-R152a. The low-density transport coefficients of the refrigerant mixtures were calculated from the new invert potentials by the classical kinetic theory. The viscosity coefficient, binar...

Abstract: The performances of thermodynamics cycles are dependent on the properties of refrigerants. The performances of Vuilleumier (VM) cycle heat pump adopting mixture refrigerants are analyzed by MATLAB software using REFPROP programming. At given operating parameters and configuration, performances of the VM cycle adopting pure refrigerant, H2, He or N2 are compared. Thermodynamic properti...

Refrigerant mixtures seem the most promising candidates as replacement fluids in refrigeration devices and heat pumps. In this paper two prediction methods are proposed for th~ evaluation of the thermal conductivity of refrigerant mixtures in their saturated liquid state and in the subcooled region. The first method is based on the use of mixing rules applied to pure refrigerant data evaluated ...

A variety of hydrofluorocarbon (HFC) compounds, both as pure substances and mixtures, are being developed as alternative refrigerants to replace the exsting chlorofluorocarbons and hydrofluorocarbons which have been linked to stratospheric ozone depletion. The use ofHFC's in refrigeration systems will require new lubricants, and polyolesters are being widely promoted as the lubricant of choice ...