GB 11062-2020
Calculation methods for natural gas calorific value, density, relative density and Wobbe index (English Version)

Standard No.

GB 11062-2020

Language

Chinese, Available in English version

Release Date

2020

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Latest

GB 11062-2020

Scope

This standard specifies methods for calculating the high calorific value, low calorific value, density, relative density, high Wobbe index and low Wobbe index of natural gas, natural gas substitutes and other gaseous fuels when the molar composition of the gas is known. Specifies methods for calculating physical property parameters of gas mixtures under commonly used reference conditions. Mole fraction is by definition the result of normalization, which can be accomplished by the methods provided in ISO 6974-1 and ISO 6974-2. The values of various pure component physical property parameters used in the calculation method and their uncertainties are given in the table, and their sources are given. At the same time, the standard uncertainty evaluation method of the calculated physical property parameter values is given. The method of calculating physical property parameters on a molar, mass or volume basis is applicable to any natural gas, natural gas substitutes and other fuels that are usually in the gaseous state. For the calculation of physical property parameters based on volume, this method is only applicable to mixtures with a compression factor greater than 0.9 under reference conditions. Appendix D gives examples of calculation methods. Note 1: The dimensionless molecular weight is numerically equal to the molar mass (kg "kmol-Note 2: The method described in this standard does not explicitly limit the composition range, but under reference conditions, the physical property parameters are calculated based on the volume of the mixture. The compression factor is greater than 0.9. Note 3: Since the mole fraction of water cannot usually be obtained from chromatographic analysis, it is common practice to first calculate the physical property parameter values of dry gas and then calculate the effect of water vapor in a separate program. If the mole fraction is known, it can be calculated according to the procedures specified in this standard. ISO/TR 29922 discusses the influence of water vapor on directly measured calorific weight and calculated calorific value. Note 4: For hydrocarbons above C , any isomer detected is included in the normal isomer with the same carbon number. Note 5: If you want to replace Ce* or Cr* in the unanalyzed component by a single virtual component, the user can do it himself. Its mole fraction is set so that the virtual components are suitable for the specific application purpose. Any "non-reactive water" and "non-flammable sulfide gas" etc. are those whose appropriate combustion value is set to 0.

GB 11062-2020 Referenced Document

• GB/T 11062 Natural gas—Calculation of calorific values, density, relative density and Wobbe indices from composition
• ISO 14912 Gas analysis - Conversion of gas mixture composition data; Technical Corrigendum 1
• ISO 6974-1 Natural gas - Determination of composition and associated uncertainty by gas chromatography - Part 1: General guidelines and calculation of composition; Technical Corrigendum 1
• ISO 6974-2 Natural gas - Determination of composition and associated uncertainty by gas chromatography - Part 2: Uncertainty calculations
• Part 1 Specifications for the Location@ Maintenance@ Operation and Testing of Railway Track Scales

GB 11062-2020 history

• 2020 GB/T 11062-2020 Natural gas—Calculation of calorific values, density, relative density and Wobbe indices from composition
• 2014 GB/T 11062-2014 Natural gas.Calculation of calorific values, density, relative density and Wobbe index
• 1998 GB/T 11062-1998 Natural gas--Calculation of calorific values, density, relative density and Wobbe index from composition