GB/T 11062-2020Natural gas - Calculation of calorific values, density, relative density and Wobbe indices from composition (English PDF)

1 Scope

This standard specifies the calculation of the high calorific value, low calorific value of natural gas, natural gas substitutes and other gas fuels when the molar composition of gas is known.

The method of calorific value, density, relative density, high Wobbe index and low Wobbe index. Specifies the calculation of gas under common reference conditions

The method of the physical parameters of the mixture.

The mole fraction is defined as a normalized result, which can be completed by the methods provided in ISO 6974-1 and ISO 6974-2.

The values and uncertainties of the physical properties of the various pure components used in the calculation method are given in the table, and their sources are given. Also give

The standard uncertainty evaluation method of the calculated physical property parameter values is presented.

The calculation method of physical property parameters based on mole, mass or volume is suitable for any natural gas, natural gas substitutes and usually gas

Other fuels in the body state. For the calculation of physical property parameters based on volume, this method is only suitable for large compressibility under reference conditions.

In a mixture of 0.9.

Appendix D gives examples of calculation methods.

Note 1.The dimensionless molecular weight is numerically equal to the molar mass (kg·kmol-1).

Note 2.The method described in this standard does not explicitly limit the composition range. However, under the reference conditions, the physical property parameter requirements are calculated based on the volume

The compression factor of the mixture is greater than 0.9.

Note 3.Since the mole fraction of water cannot usually be obtained from chromatographic analysis, the usual practice is to first calculate the physical property parameter values of the dry gas, and then perform a separate process.

Calculate the influence of water vapor in the sequence. If the mole fraction of water vapor is known, it can be calculated according to the procedure specified in this standard.

ISO /T R29922 discusses the influence of water vapor on directly measured calorific value and calculated calorific value.

Note 4.For hydrocarbons above C7, any isomers detected are included in the normal isomers of the same carbon number.

Note 5.If you need to replace C6 or C7 in the unanalyzed component with a single virtual component, the user can set its mole fraction by himself, so the virtual component

To meet specific application purposes. Any "non-reactive water" and "non-combustible hydrogen sulfide" etc. is to set the appropriate combustion enthalpy value to 0

Virtual component.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article

Pieces. For undated references, the latest version (including all amendments) applies to this document.

ISO 6974-1 Gas Chromatographic Determination of Natural Gas and Related Uncertainties in Calculation Part 1.General Guidelines and Composition Calculation

Calculated (Naturalgas-Determinationofcompositionandassociateduncertaintybygaschromatography-

Part 1.Generalguidelinesandcalculationofcomposition)

ISO 6974-2 Gas Chromatographic Determination of Natural Gas and Related Uncertainties in Calculation Part 2.Uncertainty Calculation (Naturalgas-Determinationofcompositionandassociateduncertaintybygaschromatography-

Part 2.Uncertaintycalculations)

ISO 14912.2003 Gas analysis-Conversion of gas mixture composition data (Gasanalysis-Conversion of gasmixture compositiondata)

GB 18047 | GB/T 11060.4 | GB/T 17283 | GB/T 11060.12 | GB/T 11060.1 | […]