Paulo Fialho

Density of HCFC 142b and of its mixture with HCFC 22

Abstract The density of the binary mixture 40/60 wt% of monochlorodifluoromethane (HCFC 22) and 1-chloro-1,1-difluoroethane (HCFC 142b) in the liquid phase, has been measured between 300 and 370 K and pressures up to 19 MPa, with an oscillating fork densimeter, operating in a relative mode. Toluene and vacuum have been used as calibrating fluids. The accuracy of the data is 0.08 %. An equation for the dependence of density in temperature and pressure for HCFC 142b and for this mixture is also presented.

The thermal conductivity of 1-chloro-1,1-difluoroethane (HCFC-142b)

The thermal conductivity of 1-chloro-1,1-difluoroethane (HCFC-142b) has been measured in the temperature range 290 to 504 K and pressures up to 20 MPa with a concentric-cylinder apparatus operating in a steady-state mode. These temperature and pressure ranges cover all fluid states. The estimated accuracy of the method is about 2%. The density dependence of the thermal conductivity has been studied in the liquid region.

Density of 1,1-dichloro-1-fluoroethane (HCFC 141b) as a function of temperature and pressure

The density of HCFC 141b has been measured at several temperatures between 260 and 320 K, Mid pressures up to 20 MPa, with a mechanical oscillator densimeter. The densimeter was calibrated with 2,2,4-trimethylpentane, whose density was obtained from a correlating cyuation with 0.3% uncertainty. The density data obtained for HCFC 14H) hits a reproducibility of 0.05% and an uncertainty of 0.3%. The data obtained were fitted to a Tait-type equation. which reproduced the experimental densities within 0.11 % and were compared with the data obtained in other works.

Prediction of halocarbon liquid densities by a modified hard Sphere-De Santis equation of state

Abstract The present paper describes a general scheme for the prediction of halocarbon liquid state densities based on a modified hard sphere De Santis equation of state. It is shown that it is possible to estimate the density of pure liquids solely from the critical constants and relative molecular mass to better than 1.5% for T ∗ and from saturation vapour pressures up to 20 MPa.

Prediction of liquid densities for halocarbon mixtures by a modified Hard Sphere-De Santis equation of state

In a companion paper, we dealt with the problem of predicting the liquid behaviour of pure refrigerants. It is the purpose of the present paper to extend the use of the Hard Sphere De Santis (HSDS) model by associating it with mixing and combination rules to predict the liquid state densities for mixtures of halocarbon refrigerants. The deviations obtained between the experimental data, available for binary and ternary mixtures, and the HSDS model have shown an uncertainly of 1.5% for T∗ ≤ 0.9. This was the uncertainty claimed for the model, when applied to pure fluids.