Thermodynamic Properties of five Halogenated Hydrocarbon Vapour Power Cycle Working Fluids

1973 ◽  
Vol 15 (2) ◽  
pp. 132-143 ◽  
Author(s):  
B. M. Burnside
Keyword(s):  
Equation Of State ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Halogenated Hydrocarbons ◽  
Sonic Velocity ◽  
Simulation Studies ◽  
Computer Design ◽  
Working Fluids ◽  
Power Cycle ◽  
Halogenated Hydrocarbon

Thermodynamic properties of five halogenated hydrocarbons, of importance as working fluids for small vapour power units, have been studied. The compounds are monochlorobenzene, hexafluorobenzene, o-dichlorobenzene, perfluoro-2-butyltetrahydrofuran and perfluorodecalin. With the aid of the Martin-Hou equation of state the properties of each compound, including sonic velocities and specific heat ratios, have been correlated. By comparison with the well established data for steam the accuracy of the sonic velocity and specific heat ratio values has been indicated. The information is presented in a manner which facilitates either the production of saturation and superheat tables or diagrams, or direct inclusion of the data in computer design and simulation studies of Rankine plant.

A Rational Equation of State for Water and Water Vapor in the Critical Region

1964 ◽  
Vol 86 (3) ◽  
pp. 320-326 ◽  
Author(s):  
E. S. Nowak
Keyword(s):  
Water Vapor ◽  
Equation Of State ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Critical Point ◽  
Critical Region ◽  
Constant Pressure ◽  
Parametric Equation ◽  
Enthalpy And Entropy ◽  
Specific Volumes

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.

Thermodynamic Properties of Combustion Products: Equilibrium Products of (CH2)k With Oxygen Enriched Air

1966 ◽  
Vol 88 (4) ◽  
pp. 334-344
Author(s):  
J. D. Pearson ◽  
R. C. Fellinger
Keyword(s):  
Molecular Weight ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Heat Exchangers ◽  
Oxygen Supply ◽  
Combustion Products ◽  
Sonic Velocity ◽  
Constant Composition ◽  
Specific Heat Ratio ◽  
Temperature Range

Tables giving the enthalpy, entropy, molecular weight, constant composition specific heat ratio and constant composition sonic velocity of the equilibrium combustion products of (CH2)k with oxygen enriched air have been developed. The tables cover a temperature range of 2700 to 6120 deg R and pressures from 0.01 to 25 atm. Ratios of oxygen supplied range from 1.0 to 2.0 times the stoichiometric requirement. For each oxygen supply five values of the N/O ratio, ranging from 0 to 3.73, are considered. This paper presents two of these tables. They have a ratio of oxygen to stoichiometric oxygen 1.20 and N/O ratio of 2.0 and 3.73. Several sample problems illustrating use of the tables are given, including adiabatic flame temperatures, heat exchangers, and nozzles.

Investigation of the Thermodynamic Properties of Anharmonic Crystals with Defects and Influence of Anharmonicity in Exafs by the Moment Method

1998 ◽  
Vol 12 (02) ◽  
pp. 191-205 ◽  
Author(s):  
Vu Van Hung ◽  
Nguyen Thanh Hai
Keyword(s):  
Thermal Expansion ◽  
Thermodynamic Properties ◽  
Phase Change ◽  
Specific Heat ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Moment Method ◽  
Adiabatic Compressibility ◽  
Relative Displacement ◽  
The Moment

By the moment method established previously on the basis of the statistical mechanics, the thermodynamic properties of a strongly anharmonic face-centered and body-centered cubic crystal with point defect are considered. The thermal expansion coefficient, the specific heat Cv and Cp, the isothermal and adiabatic compressibility, etc. are calculated. Our calculated results of the thermal expansion coefficient, the specific heat Cv and Cp… of W, Nb, Au and Ag metals at various temperatures agrees well with the measured values. The anharmonic effects in extended X-ray absorption fine structure (EXAFS) in the single-shell model are considered. We have obtained a new formula for anharmonic contribution to the mean square relative displacement. The anharmonicity is proportional to the temperature and enters the phase change of EXAFS. Our calculated results of Debye–Waller factor and phase change in EXAFS of Cu at various temperatures agrees well with the measured values.

Performance Analysis and Comparison Study of Transcritical Power Cycles Using CO2-Based Mixtures as Working Fluids

2016 ◽  
Author(s):  
Jiaxi Xia ◽  
Jiangfeng Wang ◽  
Pan Zhao ◽  
Dai Yiping
Keyword(s):  
Critical Temperature ◽  
Parametric Optimization ◽  
Design Parameters ◽  
Working Fluid ◽  
Comparison Study ◽  
Software Environment ◽  
Working Fluids ◽  
Power Cycles ◽  
Power Cycle ◽  
Thermodynamic Performance

CO2 in a transcritical CO2 cycle can not easily be condensed due to its low critical temperature (304.15K). In order to increase the critical temperature of working fluid, an effective method is to blend CO2 with other refrigerants to achieve a higher critical temperature. In this study, a transcritical power cycle using CO2-based mixtures which blend CO2 with other refrigerants as working fluids is investigated under heat source. Mathematical models are established to simulate the transcritical power cycle using different CO2-based mixtures under MATLAB® software environment. A parametric analysis is conducted under steady-state conditions for different CO2-based mixtures. In addition, a parametric optimization is carried out to obtain the optimal design parameters, and the comparisons of the transcritical power cycle using different CO2-based mixtures and pure CO2 are conducted. The results show that a raise in critical temperature can be achieved by using CO2-based mixtures, and CO2-based mixtures with R32 and R22 can also obtain better thermodynamic performance than pure CO2 in transcritical power cycle. What’s more, the condenser area needed by CO2-based mixture is smaller than pure CO2.

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