calculateProperties: Calculate natural gas properties per ISO 6976:2016

In ISO6976.2016: Calorific Values and Properties of Natural Gas per ISO 6976:2016

Calculate natural gas properties per ISO 6976:2016

Description

Computes all combustion and volumetric properties of a natural gas mixture together with their standard (or expanded) uncertainties, following the method and tables of ISO 6976:2016 and the uncertainty propagation formulae of its Annex B.

Usage

calculateProperties(
  compositionArray,
  uncertaintyArray,
  correlationMatrix,
  combustionTemperature = 25,
  volumeTemperature = 15,
  pressure = 101.325,
  coverage = 1
)

Arguments

compositionArray	Numeric vector of length 60: mole fractions \[mol/mol\] in the component order of ISO 6976:2016 Table A.2. See componentNames for the ordering. If values are given in mol%, divide by 100 before passing them here.
uncertaintyArray	Numeric vector of length 60: standard uncertainties of the mole fractions (same units as compositionArray).
correlationMatrix	60x60 numeric matrix of correlation coefficients between component mole fractions. Use diag(60) when correlations are unknown or assumed to be zero.
combustionTemperature	Combustion reference temperature in °C. Permitted values: 0, 15, 15.55, 20, 25. Default: 25.
volumeTemperature	Volume reference temperature in °C. Permitted values: 0, 15, 15.55, 20. Default: 15.
pressure	Reference pressure in kPa. Must be in \[90, 110\]. Default: 101.325.
coverage	Coverage factor k; uncertainties are multiplied by k before being returned. Default: 1 (standard uncertainty).

Value

A named list with the following elements (all numeric scalars):

| Name | Description | Unit | |———–|—————————————————–|————| | M | Molar mass | kg/kmol | | Z | Compression factor | — | | G_o | Ideal-gas relative density | — | | D_o | Ideal-gas density | kg/m³ | | G, u_G | Real-gas relative density and uncertainty | — | | D, u_D | Real-gas density and uncertainty | kg/m³ | | Hcg, u_Hcg| Molar gross calorific value and uncertainty | kJ/mol | | Hcn, u_Hcn| Molar net calorific value and uncertainty | kJ/mol | | Hmg, u_Hmg| Mass-basis gross calorific value and uncertainty | MJ/kg | | Hmn, u_Hmn| Mass-basis net calorific value and uncertainty | MJ/kg | | Hvg_o, u_Hvg_o | Ideal-gas vol. gross CV and uncertainty | MJ/m³ | | Hvn_o, u_Hvn_o | Ideal-gas vol. net CV and uncertainty | MJ/m³ | | Hvg, u_Hvg| Real-gas vol. gross CV and uncertainty | MJ/m³ | | Hvn, u_Hvn| Real-gas vol. net CV and uncertainty | MJ/m³ | | Wg_o | Ideal-gas gross Wobbe index | MJ/m³ | | Wn_o | Ideal-gas net Wobbe index | MJ/m³ | | Wg, u_Wg | Real-gas gross Wobbe index and uncertainty | MJ/m³ | | Wn, u_Wn | Real-gas net Wobbe index and uncertainty | MJ/m³ |

References

ISO 6976:2016 "Natural Gas — Calculation of calorific values, density, relative density and Wobbe indices from composition"

See Also

GasComponents, componentNames

Examples

data("example1")
res <- calculateProperties(example1$fractionArray, example1$uncertaintyArray,
                           example1$correlationMatrix,
                           combustionTemperature = 15, volumeTemperature = 15)
res$M      # molar mass [kg/kmol]
res$Hvg    # real-gas vol. gross CV [MJ/m^3]
res$u_Wg   # standard uncertainty of gross Wobbe index

ISO6976.2016 documentation built on April 9, 2026, 5:09 p.m.