Appendix 5: Average Constant-Pressure Specific Heat of Ideal Gases and Water Vapor, cp in kJ/(kg K)

A parametric equation of state was derived for water and water vapor in the critical region from experimental P-V-T data. It is valid in that part of the critical region encompassed by pressures from 3000 to 4000 psia, specific volumes from 0.0400 to 0.1100 ft3/lb, and temperatures from 698 to 752 deg F. The equation of state satisfies all of the known conditions at the critical point. It also satisfies the conditions along certain of the boundaries which probably separate “supercritical liquid” from “supercritical vapor.” The equation of state, though quite simple in form, is probably superior to any equation heretofore derived for water and water vapor in the critical region. Specifically, the deviations between the measured and computed values of pressure in the large majority of the cases were within three parts in one thousand. This coincides approximately with the overall uncertainty in P-V-T measurements. In view of these factors, the author recommends that the equation be used to derive values for such thermodynamic properties as specific heat at constant pressure, enthalpy, and entropy in the critical region.

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Appendix 4: Average Constant-Pressure Molar Specific Heat of Ideal Gases, µcp in kJ/(kmol K)

Advanced Energy Systems ◽

10.1201/b14928-23 ◽

2013 ◽

pp. 587-588

Keyword(s):

Specific Heat ◽

Constant Pressure ◽

Ideal Gases

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Specific heat at constant pressure, enthalpy and Gibbs free energy of boron nitride (BN) using q-deformed exponential-type potential

Physica B Condensed Matter ◽

10.1016/j.physb.2021.412940 ◽

2021 ◽

Vol 613 ◽

pp. 412940 ◽

Cited By ~ 1

Author(s):

M. Habibinejad ◽

R. Khordad ◽

A. Ghanbari

Keyword(s):

Free Energy ◽

Boron Nitride ◽

Specific Heat ◽

Gibbs Free Energy ◽

Exponential Type ◽

Constant Pressure ◽

Type Potential

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Specific heat at constant pressure from first principles: contributions from fully anharmonic vibrations

Materials Research Express ◽

10.1088/2053-1591/ab7157 ◽

2020 ◽

Vol 6 (12) ◽

pp. 125924

Author(s):

Christopher M Stanley

Keyword(s):

Specific Heat ◽

First Principles ◽

Constant Pressure ◽

Anharmonic Vibrations

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4. On the Mechanical Action of Heat. Note as to the Dynamical Equivalent of Temperature in Liquid Water, and the Specific Heat of Atmospheric Air and Steam.

Proceedings of the Royal Society of Edinburgh ◽

10.1017/s0370164600026961 ◽

1857 ◽

Vol 3 ◽

pp. 5-8

Author(s):

W. J. Macquorn Rankine

Keyword(s):

Specific Heat ◽

Liquid Water ◽

Constant Pressure ◽

Mechanical Action ◽

Atmospheric Air ◽

Apparent Specific Heat

In the author's paper on the Mechanical Action of Heat (Trans. Roy. Soc. Edin., Vol. XX., Part I), the calculations depending on the dynamical equivalent of temperature in liquid water were founded on the experiments of De la Roche and Bérard on the ratio of the apparent specific heat of atmospheric air under constant pressure to that of water. The equivalent thus obtained was about one-tenth part less than Mr Joule's. Since then, the author, having become acquainted with the details of Mr Joule's experiments, has come to the conclusion that Mr Joule's equivalent is correct to aboutof its amount, and that the discrepancy in question originates chiefly in the experiments of De la Roche and Bérard.

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Modelling and Simulation of Transient Performance of the Semi-Closed O2/CO2 Gas Turbine Cycle for CO2-Capture

Volume 3: Turbo Expo 2003 ◽

10.1115/gt2003-38068 ◽

2003 ◽

Cited By ~ 8

Author(s):

Ragnhild E. Ulfsnes ◽

Olav Bolland ◽

Kristin Jordal

Keyword(s):

Water Vapor ◽

Specific Heat ◽

Gas Turbine ◽

Transient Behavior ◽

Cycle Performance ◽

Working Fluid ◽

Transient Event ◽

Co2 Gas ◽

Specific Heat Ratio ◽

Gas Turbine Cycle

One of the concepts proposed for capture of CO2 in power production from gaseous fossil fuels is the semi-closed O2/CO2 gas turbine cycle. The semi-closed O2/CO2 gas turbine cycle has a near to stoichiometric combustion with oxygen, producing CO2 and water vapor as the combustion products. The water vapor is condensed and removed from the process, the remaining gas, primarily CO2, is mainly recycled to keep turbine inlet temperature at a permissible level. A model for predicting transient behavior of the semi-closed O2/CO2 gas turbine cycle is presented. The model is implemented in the simulation tool gPROMS (Process System Enterprise Ltd.), and simulations are performed to investigate two different issues. The first issue is to see how different cycle performance variables interact during transient behavior; the second is to investigate how cycle calculations are affected when including the gas constant and the specific heat ratio in compressor characteristics. The simulations show that the near to stoichiometric combustion and the working fluid recycle introduce a high interaction between the different cycle components and variables. This makes it very difficult to analytically predict the cycle performance during a transient event, i.e. simulations are necessary. It is also found that, except for the shaft speed calculation, the introduction of gas constant and specific heat ratio dependence on the compressor performance map will have only a minor influence on the process performance.

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