An Estimation Method for Thermal Conductivity in the Fluid Phase

An estimation method for thermal
conductivity in the gas as well
as in the liquid phase is presented in this work. The models are based
on group contributions of the second-order. Temperature dependence
could be described well if a valid reference temperature is used as
an additional input parameter. For the gas phase the critical temperature
was chosen as the reference temperature, and for the liquid phase
the normal boiling temperature was chosen. Relative errors are within
a magnitude of 10 % for the gas phase and 7 % to 14 % for the liquid
phase. Estimation quality is high for small as well as for high absolute
values of the thermal conductivity and independent of substance class
or molecule size.