The thermal conductivity of H2O + ZnCl2 solutions was measured over the temperature range
293−473 K using a parallel-plate apparatus. Data cover the pressure range from 0.1 to 100
MPa. Measurements were made on six isobars, namely, 0.1, 20, 40, 60, 80, and 100 MPa. The
concentrations studied were 2.5, 5, 10, 15, 20, and 25 wt % ZnCl2. The accuracy of the
measurements was estimated to be ±1.6%. The effect of temperature, pressure, and concentration on the thermal conductivity behavior was studied. The thermal conductivity shows a linear
dependence on pressure and concentration at all isotherms for each concentration. Along each
isobar a given concentration shows the thermal-conductivity maximum at temperatures between
405 and 417 K. The measured values of thermal conductivity are compared with the
experimental and correlation results of other investigators. Our experimental results for the
H2O + ZnCl2 system confirm the results obtained by DiGuilio et al. (DiGuilio, R. M.; et al.
ASHRAE Trans.
1990, 96, 702; DiGuilio, R. M.; Teja, A. S. Ind. Eng. Chem. Res.
1992, 31, 1081)
and Bleazard et al. (Bleazard, J. G.; et al. AIChE Symp. Ser.
1994, 298, 23; Bleazard, J. G.;
Teja, A/ S. J. Chem. Eng. Data
1995, 40, 732). The constant-composition curves are not parallel
to those for pure water at high pressures and high concentrations. A new correlation which
yields the correct temperature, pressure, and concentration behavior of thermal conductivity is
proposed. The pressure and temperature coefficients of the thermal conductivity have been
studied.
