Thermodynamic Properties of Nitrogen

Temperature Pressure Density Volume Int. energy Enthalpy Entropy C, CT Sound speed Joule-Thomson Therm, cond. Viscosity 

Temperature K Pressure MPa Density mol/dm3 Volume dmVmol Int. energy kj/mol Enthalpy kj/mol Entropy kJ/(mol-K) C kJ/(mol-K) cT kJ/(mol K) Sound speed m/s Joule-Thomson K/MPa Therm, cond. mW/(m-K) Viscosity jPa-s 

For viscosity, the uncertainty is 0.5% in dilute gas. Away from the dilute gas (pressures greater than 1 MPa and in the liquid), the uncertainties are as low as 1% between 270 and 300 K at pressures less than 100 MPa, and increase outside that range. The uncertainties are around 2% at temperatures of 180 K and higher. Below this and away from the critical region, the uncertainties steadily increase to around 5% at the triple points of the fluids. The uncertainties in the critical region are higher. 

For thermal conductivity, the uncertainty for the dilute gas is 2% with increasing uncertainties near the triple point. For the nondilute gas, the uncertainty is 2% for temperatures greater than 150 K. The uncertainty is 3% at temperatures less than the critical point and 5% in the critical region, except for states very near the critical point. 

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Jacobson, R.T. and Stewart, R.B., Thermodynamic properties of nitrogen including liquid and vapor phases from 63 K to 2000 K with pressures to 10,000 bar, J. Phys. Chem. Ref. Data, 2, 757, 1973. 

FIG. 2-13 Pressure-enthalpy diagram for nitrogen. Properties computed with the NIST REFPROP Database, Version 7.0 (Lemmon, E. W., McLinden, M. O., and Huber, M. L., 2002, NIST Standard Reference Database 23, NIST Reference Fluid Thermodynamic and Transport Properties—REFPROP, Version 7.0, Standard Reference Data Program, National Institute of Standards and Technology), based on the equation of state of Span, R., Lemmon, E. W., Jacobsen, R. T., Wagner, W., and Yokozeki, A,. A Reference Equation of State for the Thermodynamic Properties of Nitrogen for Temperatures from 63.151 to 1000... 

TABLE 2-241 Thermodynamic Properties of Nitrogen Trifluoride (Concluded)... 

V. V. Sychev, T. B. Selover (Eds.), Thermodynamic Properties of Nitrogen, Hemisphere Publishing Corp., Washington, DC, 1987. 

Thomas R. Strobridge, The Thermodynamic Properties of Nitrogen from 64 to 300° K between 0.1 and 200 Atmospheres, National Bureau of Standards Technical Note TN 129, U.S. Government Printing Office, Washington, D.C., 1962, 85 pp. 

The equation of state selected for this work was developed by Strobridge for a correlation of thermodynamic properties of nitrogen ... 

Jacobsen, R. T., The thermodynamic properties of nitrogen from 65 to 2000 K with pressures to 10,000 atmospheres, Ph.D. dissertation, Washington State University, Pullman, 1972. 

In summary, to obtain similar thermod5mamic efficiency, it appears that nitrogen-based systems will have somewhere around 40% larger volume than helium-based systems. Their capital cost will be higher because of the less optimal thermodynamic properties of nitrogen compared with helium. However, the nitrogen-based Brayton cycle is expected to be less expensive than the equivalent Rankine steam cycle because of the low-pressure steam components and the moisture separator components required for the Rankine cycle. 

O. T. Bloomer and K. N. Rao, "Thermodynamic Properties of Nitrogen," Institute of Gas Technology Research Bulletin 18, October, 1952. 

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