.AixLib.Media.Refrigerants.R134a.R134a_IIR_P1_395_T233_455_Formula

Information

This package provides a refrigerant model for R134a using a hybrid approach developed by Sangi et al.. The hybrid approach is implemented in AixLib.Media.Refrigerants.Interfaces.PartialHybridTwoPhaseMediumFormula and the refrigerant model is implemented by complete the template AixLib.Media.Refrigerants.Interfaces.TemplateHybridTwoPhaseMediumFormula .

Assumptions and limitations

The implemented coefficients are fitted to external data by Engelpracht and are valid within the following range:

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Parameter

Minimum Value

Maximum Value

Pressure (p) in bar

1

39.5

Temperature (T) in K

233.15

455.15

The reference point is defined as 200 kJ/kg and 1 kJ/kg/K, respectively, for enthalpy and entropy for the saturated liquid at 273.15 K.

Validation

The model is validated by comparing results obtained from the example model AixLib.Media.Refrigerants.Examples.RefrigerantProperties to external data (e.g. obtained from measurements or external media libraries).

References

Tillner-Roth, R.; Baehr, H. D. (1994): An International Standard Formulation for the thermodynamic Properties of 1,1,1,2|Tetrafluoroethane (HFC|134a) for Temperatures from 170 K to 455 K and Pressures up to 70 MPa. In: Journal of physical and chemical reference data (23), S. 657–729. DOI: 10.1063/1.555958 .

Huber, Marcia L.; Laesecke, Arno; Perkins, Richard A. (2003): Model for the Viscosity and Thermal Conductivity of Refrigerants, Including a New Correlation for the Viscosity of R134a. In: Ind. Eng. Chem. Res. 42 (13) , S. 3163–3178. DOI: 10.1021/ie0300880 .

Perkins, R. A.; Laesecke, A.; Howley, J.; Ramires, M. L. V.; Gurova, A. N.; Cusco, L. (2000): Experimental thermal conductivity values for the IUPAC round-robin sample of 1,1,1,2-tetrafluoroethane (R134a). Gaithersburg, MD: National Institute of Standards and Technology.

Mulero, A.; Cachadiña, I.; Parra, M. I. (2012): Recommended Correlations for the Surface Tension of Common Fluids. In: Journal of physical and chemical reference data 41 (4), S. 43105. DOI: 10.1063/1.4768782 .

Engelpracht, Mirko (2017): Development of modular and scalable simulation models for heat pumps and chillers considering various refrigerants. Master Thesis

Contents

NameDescription
 SmoothTransitionRecord that contains ranges to calculate a smooth transition between different regions
 f_IdgDimensionless Helmholtz energy (Ideal gas contribution alpha_0)
 f_ResDimensionless Helmholtz energy (Residual part alpha_r)
 t_fIdg_tShort form for tau*(dalpha_0/dtau)_delta=const
 tt_fIdg_ttShort form for tau*tau*(ddalpha_0/(dtau*dtau))_delta=const
 t_fRes_tShort form for tau*(dalpha_r/dtau)_delta=const
 tt_fRes_ttShort form for tau*tau*(ddalpha_r/(dtau*dtau))_delta=const
 d_fRes_dShort form for delta*(dalpha_r/(ddelta))_tau=const
 dd_fRes_ddShort form for delta*delta(ddalpha_r/(ddelta*delta))_tau=const
 td_fRes_tdShort form for tau*delta*(ddalpha_r/(dtau*ddelta))
 ttt_fIdg_tttShort form for tau*tau*tau*(dddalpha_0/(dtau*dtau*dtau))_delta=const
 ttt_fRes_tttShort form for tau*tau*tau*(dddalpha_r/(dtau*dtau*dtau))_delta=const
 ddd_fRes_dddShort form for delta*delta*delta* (dddalpha_r/(ddelta*ddelta*ddelta))_tau=const
 tdd_fRes_tddShort form for tau*delta*delta*(dddalpha_r/(dtau*ddelta*ddelta))
 ttd_fRes_ttdShort form for tau*tau*delta*(dddalpha_r/(dtau*dtau*ddelta))
 saturationPressureSaturation pressure of refrigerant (Ancillary equation)
 saturationTemperatureSaturation temperature of refrigerant (Ancillary equation)
 bubbleDensityBoiling curve specific density of refrigerant (Ancillary equation)
 dewDensityDew curve specific density of refrigerant (Ancillary equation)
 bubbleEnthalpyBoiling curve specific enthalpy of refrigerant (Ancillary equation)
 dewEnthalpyDew curve specific enthalpy of refrigerant (Ancillary equation)
 bubbleEntropyBoiling curve specific entropy of refrigerant (Ancillary equation)
 dewEntropyDew curve specific entropy of propane (Ancillary equation)
 temperature_phCalculates temperature as function of pressure and specific enthalpy
 temperature_psCalculates temperature as function of pressure and specific entroy
 density_pTComputes density as a function of pressure and temperature
 dynamicViscosityCalculates dynamic viscosity of refrigerant
 thermalConductivityCalculates thermal conductivity of refrigerant
 surfaceTensionSurface tension in two phase region of refrigerant

Revisions


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