Home / C003 – ISO 6976:1995 Calorific Value and Relative Density

C003 – ISO 6976:1995 Calorific Value and Relative Density

Description

This calculates calorific values, density, relative density and Wobbe index from a gas composition. Results are calculated for the composition treated as both a real and an ideal gas, inferior (net) and superior (gross) calorific value and Wobbe index are displayed in each case. This version of the calculation included both the definitive and alternative methods of calculating the calorific value on a volumetric basis.

References

FLOCALC Calculation reference F003

Kelton calculation reference C003

Kelton calculation reference C111

International standard, Natural Gas – Calculation of calorific values, density, relative density and Wobbe index (ISO 6976: 1995/BS 7589)

International Standard, Natural gas – Standard reference conditions (ISO 13443:1996)

Options

Hydrocarbon Tail

  • No Tail
  • C6 Tail
  • C7 Tail
  • C9 Tail

Select the appropriate hydrocarbon tail. Where a tail is selected the percentage split of each component is entered, this is generally obtained from laboratory analysis.

Reference Temperature (Combustion/Metering)

  • 25/0
  • 15/0
  • 0/0
  • 15/15
  • 25/20
  • 20/20
  • 25/15
  • User entered reference conditions (ISO 13443)

This option is used to select the reference temperature used for the calculation. There is a choice of various combustion/metering temperatures used around the world or to manually enter base pressure, combustion and metering temperatures which will use the equations set out in ISO 13443:1996 to correct values from ISO standard conditions to those entered by the user.

Molecular Weights

  • Rounded
  • Full Precision

This option gives the choice to use the rounded molecular weights as shown in Table 1, or calculate the molecular weights with full precision using the elemental molars masses shown beneath Table 1.

Ideal Gas Calorific Value (Mass) Method

  • Definitive (Table 3)
  • Alternative (Table 4)

This option is used to select whether the mass calorific value is calculated using the alternative or definitive tables.

Ideal Gas Calorific (Volumetric) Method

  • Definitive (Table 3)
  • Alternative (Table 5)

This option is used to select whether the volumetric calorific value is calculated using the alternative or definitive tables.

Gas Analysis

  • Extended Analysis
  • Refinery/Trace Gases

These boxes can be checked to include a wider range of compounds in the composition.

Calculation

This performs the calculations from C111 when set for 1995

 

Back