Thermodynamic Properties of Nitrogen Including Liquid and Vapor Phases from 63 K to 2000 K with Pressures to 10,000 Bar

Abstract

A new fundamental equation explicit in Helmholtz energy for thermodynamic properties of nitrogen from the freezing line to 2000 K Ilt pressures to 1000 MPa 13 presented. New independent equations for the vapor pressure and for the saturated liquid and vapor densities as functions of temperature are also included. The fundamental equation was selected from a comprehensive function of 100 terms on the basis of a statistical analysis of the quality of the fit. The coefficients of the fundamental equation were determined by a weighted least-squares fit to selected P-p-T data, saturated liquid, and saturated vapor density data to define the phase equilibrium criteria for coexistence, and velocity of sound data. The fundamental equation and the derivative functions for calculating internal energy, enthalpy, entropy, isochoric heat capacity (C v), isobaric heat capacity (C p), and velocity of sound are included. Tables of thermodynamic properties of nitrogen are given for liquid and vapor states within the range of validity of the fundamental equation. The fundamental equation reported here may generally be used to calculate pressures and densities with an uncertainty of ± 0.1 %, heat capacities within ± 3%, and" velocity of sound values within ± 1 %. Comparisons of calculated properties to experimental data are included to verify the accuracy of the formulation.

Measurements of the (p, ρ,T) properties and virial coefficients of pure water, methane,n-hexane,n-octane, benzene, and of their aqueous mixtures in the supercritical region

“…(72) The simplified equations for the changes in the pressure and densities due to the shift in temperature scale are: dp = (T 90 − T 68 )dp/dT and dr = (T 90 − T 68 )dr/dT, where dp = p(90) − p (68) and dr = r(90) − r (68). We have used these equations to assess the effects of the changes from the IPTS-68 to the ITS-90 on the pressures and densities for the investigated fluids in the range of pressure from 1 MPa to 95 MPa.…”

A numerical study of fluid injection and mixing under near-critical conditions

“…where A n are the coefficients given in detail by Jacobsen and Stewart [25]. Thermodynamic properties, such as enthalpy, internal energy and constant pressure specific heat, can be expressed as the sums of ideal-gas properties at the same temperature and departure functions which take into account the densefluid correction [1], …”

Nitrogen

“…Some physical properties of nitrogen (comprehensive data are given in [1][2][3][4][5][6][7][8][9][10][11][12]) are as follows: …”