Effect of temperature and pressure on the thermal conductivity of aqueous Cal2 solutions

Measurements of the thermal conductivity of aqueous CaI2 solutions in the temperature range 293-473 K and pressures up to 100 MPa for concentrations between 0 and 25 wt% are described. The accuracy of the derived data is estimated to be within +/-1.6%. A guarded parallel-plate apparatus with a cylindrical thermal conductivity cell was used, with a gap of 301.0 +/-0.1 mum between the plates and temperature differences of 0.9-1.2 K. The effect of temperature, pressure, and concentration on the thermal conductivity behaviour was studied. The pressure and temperature coefficients of the behaviour of the thermal conductivity have been studied with the use of derived experimental thermal conductivity data. A new correlation for thermal conductivity of H2O + CaI2 solutions was developed which incorporates the correct temperature, pressure, and concentration behaviour. The data obtained have been used to test the prediction and estimation techniques developed by other authors. The thermal conductivity shows an almost linear dependence on pressure at all measured isotherms for each concentration. Along each isobar a given concentration shows the thermal conductivity maximum at temperatures between 405 K and 417 K. The effects of pressure and concentration on the thermal conductivity maximum temperatures have been studied.