GB/T 11062-2020 Active

This standard specifies the methods for calculating the gross calorific value, net calorific value, density, relative density, gross Wobbe index, and net Wobbe index of natural gas, natural gas substitutes, and other gaseous fuels when the molar composition of the known gases is known. It also specifies the methods for calculating the physical properties of gas mixtures under commonly used reference conditions.
The molar fraction is defined as a normalized result, which can be achieved by the methods provided in ISO 6974-1 and ISO 6974-2.
The values of various physical properties of pure components used in the calculation methods and their uncertainties are given in the table, together with their sources. At the same time, the standard uncertainty evaluation method for the calculated physical property values is also provided.
The calculation methods of physical properties based on moles, mass, or volume are applicable to any natural gas, natural gas substitutes, and other fuels that are typically in a gaseous state. For the calculation of physical properties based on volume, this method is only applicable to mixtures with a compression factor greater than 0.9 under reference conditions.
Appendix D provides an example of the calculation methods.