Thermodynamic Properties of Nitrogen from the Freezing Line to 2000 K at Pressures to 1000 MPa

TLDR: In this paper, a new fundamental equation explicit in Helmholtz energy for thermodynamic properties of nitrogen from the freezing line to 2000 K at pressures to 1000 MPa is presented, and the derivative functions for calculating internal energy, enthalpy, entropy, isochoric heat capacity, isobaric heat capacity (Cv), and velocity of sound are included.

Abstract: A new fundamental equation explicit in Helmholtz energy for thermodynamic properties of nitrogen from the freezing line to 2000 K at pressures to 1000 MPa is 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‐ρ‐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 (Cv), isobaric heat capacity (Cp), and velocity of sound are included. Tables of thermodynamic properties of nitrogen are given for liquid and vapor states within the range of...