Thermophysical Properties of the Refrigerant Mixtures R417A and R417B from Dynamic Light Scattering (DLS)

Abstract

Dynamic light scattering (DLS) has been used for the measurement of several thermophysical properties of the refrigerant mixtures R417A (50 % by mass 1,1,1,2-tetrafluoroethane-R134a, 46.6 % pentafluoroethane-R125, 3.4 % n-butane-R600) and R417B (79 % by mass R125, 18.25 % R134a, 2.75 % R600). Both refrigerant mixtures are designed for a replacement of R22 (chlorodifluoromethane) in existing refrigeration systems. Thermal diffusivity and sound speed have been obtained by light scattering from the bulk fluid for the liquid phase under saturation conditions over a temperature range from about 283 K up to the liquid-vapor critical point with estimated uncertainties between 1 % and 3 % and between 0.5 % and 2 %, respectively. By applying the method of DLS to a liquid-vapor interface, also called surface light scattering, the saturated liquid kinematic viscosity and surface tension have been determined simultaneously. These properties have been measured from 253.15 K up to the liquid-vapor critical point with estimated uncertainties between 1 % and 3 % for kinematic viscosity and between 1 % and 2 % for surface tension. The measured thermal diffusivity, sound speed, kinematic viscosity, and surface tension are represented by interpolating expressions with differences between the experimental and calculated values that are comparable with but always smaller than

Binary Diffusion Coefficients of the Liquid Organic Hydrogen Carrier System Dibenzyltoluene/Perhydrodibenzyltoluene

“…The last part takes a convergence of the experimental data at lower temperatures into account. This term was adopted from a fit equation which was formerly used to describe thermal diffusivity data of refrigerants as a function of temperature . The resulting fit parameters as well as the root-mean-square (rms) deviation of the experimental data from eq are summarized in Table .…”

“…This term was adopted from a fit equation which was formerly used to describe thermal diffusivity data of refrigerants as a function of temperature. 20 The resulting fit parameters as well as the root-mean-square (rms) deviation of the experimental data from eq 6 are summarized in Table 4. The lower part of Figure 4 shows that the relative deviations of the experimental data from the fits on the basis of eq 6 are clearly smaller than the expanded uncertainty.…”

Mechanical Vapour Compression Refrigeration System: Review Part 1: Environment Challenge

“…Heller, Rausch [62] Experimental study to measure the thermophysical properties of mixture R417A and R417B.…”

Speed of Sound Measurement in 1-Methoxy-2-propanol from (306.81 to 648.29) K and up to 10 MPa

“…The BLS technique is able to measure several thermodynamic properties accurately over a wide thermodynamic region. − A laser beam transmitting through the transparent sample induces the light scattering because of the motion of molecules. From the spectrum of scattered light, thermophysical properties of the fluid such as the speed of sound, thermal diffusivity, and mutual diffusion coefficient can be derived.…”