FE-AGA8-Part2-DLL

FE-AGA8-Part2-DLL (felib.aga8xq1704p2) is a component of felib.dll.
Felib.aga8xq1704p2 performs the calculation of thermodynamic and volumetric properties of natural gas completely in accordance with:

AGA8 Report No. 8, Part 2
Thermodynamic Properties of Natural Gas and Related Gases -
GERG–2008 Equation of State
First Edition April 2017

Description of felib.aga8xq1704p2 class interface: properties (variables), method (function) and error status flags.

PROPERTIES
Property		Set property value	Get property value
I	X(I): mole fraction for	Set property value	Get property value
0	Methane	void SetMoleFraction(short I, double X(I))	double GetMoleFraction(short I)
1	Nitrogen
2	Carbon dioxide
3	Ethane
4	Propane
5	i-Butane
6	n-Butane
7	i-Pentane
8	n-Pentane
9	n-Hexane
10	n-Heptane
11	n-Octane
12	n-Nonane
13	n-Decane
14	Hydrogen
15	Oxygen
16	Carbon monoxide
17	Water
18	Hydrogen sylfide
19	Helium
20	Argon
Pressure [MPa]		void SetPressureMPa(double newP)	double GetPressureMPa()
Temperature [K]		void SetTemperatureK(double newT)	double GetTemperatureK()
^*Ranges of application (RAP)		void SetRangeOfApplication(short newRAP)	short GetRangeOfApplication()
Protection key		void SetKeyCode(long newValue)	n/a
Density [kg/m³]		void SetDensity(double newD)	double GetDensity()
Reduced density		void SetReducedDensity(double newRD)	double GetReducedDensity()
Molar mass [kg/kmol]		n/a	double GetMolarMass()
Molar density [kg⋅mole/m³]		n/a	double GetMolarDensity()
Compressibility factor		n/a	double GetCompressibilityFactor()
Molar Gibbs free energy [kj/kmol]		n/a	double GetMolarGibsFreeEnergy()
Molar internal energy [kJ/kmol]		n/a	double GetMolarInternalEnergy ()
Specific internal energy [kJ/kg]		n/a	double GetSpecificInternalEnergy ()
Molar enthalpy [kJ/kmol]		n/a	double GetMolarEnthalpy ()
Specific enthalpy [kJ/kg]		n/a	double GetSpecificEnthalpy ()
Molar entropy [kJ/(kmol⋅K)]		n/a	double GetMolarEntropy ()
Specific entropy [kJ/(kg⋅K)]		n/a	double GetSpecificEntropy ()
Molar isochoric heat capacity [kJ/(kmol⋅K)]		n/a	double GetMolarIsochoricHeatCapacity ()
Specific isochoric heat capacity [kJ/(kg⋅K)]		n/a	double GetSpecificIsochoricHeatCapacity ()
Molar isobaric heat capacity [kJ/(kmol⋅K)]		n/a	double GetMolarIsobaricHeatCapacity ()
Specific isobaric heat capacity [kJ/(kg⋅K)]		n/a	double GetSpecificIsobaricHeatCapacity ()
Joule-Thomson coefficient [K/MPa]		n/a	double GetJouleThomsonCoefficient ()
Isentropic exponent		n/a	double GetIsentropicExponent ()
Speed of sound [m/s]		n/a	double GetSpeedOfSound ()
^**Error status		n/a	long GetErrorFlag()
^***Error report		n/a	BSTR GetErrorReport()

FUNCTION
long Calculate(short iCalc); Calculates the properties and returns long error status
short iCalc - defines method of calculation	Input parameters to selected method of calculation
iCalc=0 (or any iCalc≠1 & ≠2)	Pressure, temperature and mole fractions
iCalc=1	Mass-based density, temperature and mole fractions
iCalc=2	Reduced density, temperature and mole fractions

^*Ranges of application RAP (short RAP)
Parameter	RAP=0	RAP=1	RAP=2
Pressure (absolute) in MPa	>0 to 35	>0 to 70	>0 to 70
Temperature in K	90 to 450	60 to 700	60 to 700
Reduced density	5⋅10^-9 to 6.00	5⋅10^-9 to 6.00	5⋅10^-9 to 6.00
Mole fractions ranges
Methane	0.7 to 1.00	0.3 to 1.00	0 to 1.00
Nitrogen	0 to 0.20	0 to 0.55	0 to 1.00
Carbon dioxide	0 to 0.20	0 to 0.30	0 to 1.00
Ethane	0 to 0.10	0 to 0.25	0 to 1.00
Propane	0 to 0.035	0 to 0.14	0 to 1.00
i-Butane + n-Butane	0 to 0.015	0 to 0.06	0 to 1.00
i-Pentane + n-Pentane	0 to 0.005	0 to 0.005	0 to 1.00
n-Hexane	0 to 0.001	0 to 0.002	0 to 1.00
n-Heptane	0 to 0.0005	0 to 0.001	0 to 1.00
Octane + Nonane + Decane	0 to 0.0005	0 to 0.0005	0 to 1.00
Hydrogen	0 to 0.10	0 to 0.40	0 to 1.00
Oxygen	0 to 0.0002	0 to 0.02	0 to 1.00
Carbon monoxide	0 to 0.03	0 to 0.13	0 to 1.00
Water	0 to 0.00015	0 to 0.0002	0 to 1.00
Hydrogen sulfide	0 to 0.0002	0 to 0.27	0 to 1.00
Helium	0 to 0.005	0 to 0.005	0 to 1.00
Argon	0 to 0.0002	0 to 0.0005	0 to 1.00
RAP=0 corresponds to NORMAL RANGE for Pressure and Temperature and PIPELINE QUALITY RANGE for mole fractions of natural gas, see AGA8-Part2:2017 RAP=1 corresponds to FULL RANGE for P and T and INTERMEDIATE QUALITY RANGE for mole fractions of natural gas, see AGA8-Part2:2017 RAP=2 corresponds to FULL RANGE for Pressure and Temperature and NO RANGE LIMITATIONS for mole fractions of natural gas Note that RAP=2 is not in accordance with AGA8-Part2:2017. Use it only for testing purposes e.g. for examples which do not satisfy neither RAP=0 nor RAP=1.

^**ERROR STATUS
long GetErrorFlag()	Description of Error/Warning flags.
Bit 0 =1 (000001H)	Error: There exists at least one mole fraction <0 or >1.
Bit 1 =1 (000002H)	Error: Total sum of mole fractions <0.999999 or >1.000001.
Bit 2 =1 (000004H)	Warning: Absolute temperature T<200. This flag warns that the calculated thermodynamic properties may be invalid but, the calculated volumetric properties (reduced density, mass density and compression factor) are valid if only this bit is set.
Bit 3 =1 (000008H)	Error: Mole fraction of Methane out of range defined by RAP
Bit 4 =1 (000010H)	Error: Mole fraction of Nitrogen out of range defined by RAP
Bit 5 =1 (000020H)	Error: Mole fraction of Carbon Dioxide out of range defined by RAP
Bit 6 =1 (000040H)	Error: Mole fraction of Ethane out of range defined by RAP
Bit 7 =1 (000080H)	Error: Mole fraction of Propane out of range defined by RAP
Bit 8 =1 (000100H)	Error: Mole fraction of Water out of range defined by RAP
Bit 9 =1 (000200H)	Error: Mole fraction of Hydrogen sulfide out of range defined by RAP
Bit 10 =1 (000400H)	Error: Mole fraction of Hydrogen out of range defined by RAP
Bit 11 =1 (000800H)	Error: Mole fraction of Carbon monoxide out of range defined by RAP
Bit 12 =1 (001000H)	Error: Mole fraction of Oxygen out of range defined by RAP
Bit 13=1 (002000H)	Error: Mole fraction of (i-Butane + n-Butane) out of range defined by RAP
Bit 14 =1 (004000H)	Error: Mole fraction of (i-pentane + n-Pentane) out of range defined by RAP
Bit 15 =1 (008000H)	Error: Mole fraction of n-Hexane out of range defined by RAP
Bit 16 =1 (010000H)	Error: Mole fraction of n-Heptane out of range defined by RAP
Bit 17 =1 (020000H)	Error: Mole fraction of (n-Octane + n-Nonane + n-Decane) out of range defined by RAP
Bit 18 =1 (040000H)	Error: Mole fraction of Helium out of range defined by RAP
Bit 19 =1 (080000H)	Error: Mole fraction of Argon out of range defined by RAP
Bit 20 =1 (100000H)	Error: Pressure (absolute) out of range defined by RAP
Bit 21 =1 (200000H)	Error: Temperature out of range defined by RAP
Bit 22 =1 (400000H)	Error: Reduced density out of range
Bit 23 =1 (800000H)	Error: Incorrect protection key
Bit 24,...	All higher bits are unused.

^***ERROR REPORT
The property "BSTR GetErrorReport()" is used to get an error report in a textual form. Example 1 The Error report is illustrated by a calculation example using gas mixture denoted by Gas 5 in the Table B.1 of Annex B of AGA8 Report No. 8, Part 2 with the corresponding pressure (31.4347MPa) and temperature (350K). The calculation method based on pressure, temperature and mole fractions(iCalc=0) is selected. In the first example the calculation is performed with "No range limits" (RAP=2). Upon completion of the method there were no errors and the property "BSTR GetErrorReport()" returns the the following error report string: No errors The following is a user interface to a simple VB program displaying the results and error status obtained upon completion of the calculation. Example 2 Example 2 is the same as the Example 1, except "Full range" (RAP=1) is selected instead of "No range limits" (RAP=2). Upon completion of the calculation method the range violation errors were set and the property "BSTR GetErrorReport()" returns the following error report string: ErrBit03: Mole fraction of Methane out of range defined by RAP ErrBit14: Mole fraction of Oxygen out of range defined by RAP ErrBit18: Mole fraction of Helium out of range defined by RAP ErrBit19: Mole fraction of Argon out of range defined by RAP The following is a user interface to a VB program displaying error status after failing to complete the calculation.

^***ERROR REPORT

The property "BSTR GetErrorReport()" is used to get an error report in a textual form.

Example 1

The Error report is illustrated by a calculation example using gas mixture denoted by Gas 5 in the Table B.1 of Annex B of AGA8 Report No. 8, Part 2 with the corresponding pressure (31.4347MPa) and temperature (350K). The calculation method based on pressure, temperature and mole fractions(iCalc=0) is selected. In the first example the calculation is performed with "No range limits" (RAP=2). Upon completion of the method there were no errors and the property "BSTR GetErrorReport()" returns the the following error report string:

No errors

The following is a user interface to a simple VB program displaying the results and error status obtained upon completion of the calculation.

Example1 screenshot

Example 2

Example 2 is the same as the Example 1, except "Full range" (RAP=1) is selected instead of "No range limits" (RAP=2). Upon completion of the calculation method the range violation errors were set and the property "BSTR GetErrorReport()" returns the following error report string:

ErrBit03: Mole fraction of Methane out of range defined by RAP
ErrBit14: Mole fraction of Oxygen out of range defined by RAP
ErrBit18: Mole fraction of Helium out of range defined by RAP
ErrBit19: Mole fraction of Argon out of range defined by RAP

The following is a user interface to a VB program displaying error status after failing to complete the calculation.

Example2 screenshot