Thermal conductivity of poly(ethylene glycols) and their binary mixtures

Abstract

A transient hot-wire method was used to measure the thermal conductivities of the first six members of the poly(ethylene glycol) series at 1 atm and In the temperature range 295-480 K. The method was used on a relative basis, and the accuracy of the measurements Is estimated to be ±2%. The thermal conductivities of the binary systems ethylene glycol + trl(ethylene glycol), dl(ethylene glycol) + trl(ethylene glycol), and dl(ethylene glycol) + hexa(ethylene glycol) were also measured over the whole composition range at 1 atm and 295-480 K. The pure liquid data were correlated with use of a carbon number approach, and a linear mixing rule was used to extend the correlation to mixtures of poly(ethylene glycols). Agreement between prediction and experiment was within experimental error.

Models for viscosity, thermal conductivity, and surface tension of selected pure fluids as implemented in REFPROP v10.0

“…We estimate the uncertainty of the viscosity in the liquid phase above atmospheric pressure and in the vapor phase to be on the order of 20 %. For thermal conductivity, gas-phase data were not ______________________________________________________________________________________________________ found, and very limited liquid data at atmospheric pressure (R. DiGuilio & Teja, 1990; Yu. L. Rastorguev & Gazdiev, 1969) were used to obtain the coefficients in Table 3.…”

Heat transfer in nanoparticle suspensions: Modeling the thermal conductivity of nanofluids

“…In contrast, Yang and Han 49 studied dispersions of Bi 2 Te 3 nanorods in perfluorohexane and reported a decrease in the effective thermal conductivity as the temperature increased from 278 to 323 K. As noted previously, the thermal conductivity of nonpolar liquids generally decreases monotonically with increasing temperature, 8 whereas that of associating liquids such as water generally exhibits a maximum in the thermal conductivity vs. temperature behavior. 9,10 In the case of water, the maximum occurs at $404 K. As many of the measurements on aqueous nanofluids have been made at temperatures below 400 K, they are in the region where the thermal conductivity of water increases with temperature. Also, as the volume fraction of particles in nanofluids is generally small, it is likely that the thermal conductivity of nanofluids is dominated by the thermal conductivity of the base fluid.…”

“…In addition, the thermal conductivity of nonpolar liquids decreases monotonically with increasing temperature due to thermal expansion of the liquid. 8 On the other hand, associating liquids such as water and ethylene glycol display a maximum in their thermal conductivity vs. temperature behavior [9][10][11] due to changes in the hydrogen bonding network with temperature. At low temperatures, some of the energy being transferred is stored in hydrogen bonds as they form a network, leading to a lower thermal conductivity.…”

Application of the Multi-Current Transient Hot-Wire Technique for Absolute Measurements of the Thermal Conductivity of Glycols

“…This confirms the reliable operation of our experimental setup. Agreement Open circles represent data from Assael et al [9]; solid triangles from Touloukian et al [10]; open down triangles from Bohne et al [12]; open diamonds from DiGuilio and Teja [11]; while the solid curves in (b1) and (b2) represent the correlation proposed by Obermeier et al [13].…”

“…Furthermore, we add data from literature sources to Fig. 3 for comparisons [9][10][11][12][13]. In Fig.…”