First Approximation Of Fuel Gas Consumption For Gas Turbine Driven Compressor Station

A lot of us are required to do preliminary utility estimation calculations during the Feasibility / Concept stage of a project. Another terminology often used is the Pre-FEED stage of a project. In fact this is often where non-availability of data or insufficient data becomes a bottle-neck. In such cases some minimum data with certain empirical calculation methods help to arrive at figures which may be used to for high end (+/- 30%) cost estimation of a project and help establish its feasibility.

Today's blog entry as the subject line says, is with regards to compressor stations, for transport of natural gas through long-distance pipelines. An approximation for fuel consumption can be done using certain empirical formulas. The formula is presented herewith:

F = (14 / NHV)*(P_turbine + P_auxiliary)

where:

F = Fuel Gas consumption of the compressor and the auxiliary systems associated with the compressor, Sm³/h

NHV = "Net heating Value" of the Fuel Gas to be used, MJ/Sm³ (eg: Natural Gas ~ 41 MJ/Sm³ with a certain composition)

P_turbine = Turbine power requirement, kW

P_auxiliary = Power consumption in kW of auxiliaries associated with the compressor package, which includes electricity, lubricating oil system, cooling system etc.. This has a strong dependency on local climatic conditions and on the extent of gas sourced power used for such auxiliaries.

Note: Sm³ refers to standard cubic meter at standard conditions of temperature (15 deg C ) and pressure (101.325 kPa (abs))