The thermal conductivity of hydrogen for pressures up to 660 atm and temperatures between 1.6 and 74.6°C

Abstract

Thermal conductivity measurements have been made for hydrogen using a coaxial cylindrical cell. These measurements were carried out at 1.6, 25.0, 50.2, and 74.6°C and pressures up to 660 atm. To eliminate convective and radiative contributions, the maximum temperature difference across the confined gas layer never exceeded 0.45°C. The accuracy of the resulting thermal conductivity values is estimated to be 2.5%. These values were used to test the available theoretical equations for predicting the effect of pressure on thermal conductivity. These equations result from a rigid spherical model, and all were found to be inadequate for representing the effect of pressure on this transport property for hydrogen. A nonlinear relationship between the residual thermal conductivity, k- k ∗, and the reduced density, ϱ R, adequately represented the data for the four isotherms of this study for hydrogen and those previously reported in the literature for the gaseous and liquid states of this substance. Another relationship between k- k ∗ and the quantity ( ∂P R ∂T R ) ρR was found to be linear on a log-log basis throughout the gaseous and liquid regions. These residual thermal conductivity relationships adequately define the effect of temperature and pressure on thermal conductivity for hydrogen.