Reference Correlation of the Thermal Conductivity of Nitrogen from the Triple Point to High Temperatures and Pressures

Abstract

A new wide-ranging correlation for the thermal conductivity of nitrogen, based on the most recent ab initio dilute gas theoretical calculations, a simplified crossover critical enhancement contribution, and critically evaluated experimental data, is presented. The correlation is designed to be used with a high-accuracy Helmholtz equation of state over the range of temperatures from the triple-point temperature to 1000 K, and at pressures up to 2200 MPa. The estimated expanded uncertainty (at the 95 % confidence level) in the range of validity of the correlation ranges from a minimum of 1 % in the gas phase for temperatures from 102 K to 700 K at pressures up to 1 MPa, to 4 % in the high temperature, high pressure region covering 500 K < T < 744 K at pressures from 1 MPa to 40 MPa. In the gas and supercritical region 112 K < T < 475 K for pressures 1 MPa < p < 1000 MPa the estimated uncertainty is 2.2 %, and for the liquid from 81 K to 122 K at pressures up to 70 MPa the estimated uncertainty is 3 %. The correlation behaves in a physically reasonable manner when extrapolated to temperatures below the triple point and is suitable for use in certain corresponding-states applications. However, care should be taken when using the correlation outside of the experimentally validated range.