Performances of Gas Turbines in Oil and Gas Applications: Simple Thermodynamic Methods Help Predict Major Trends

Abstract

While reliability stays the most critical requirement for power generation in the Oil & Gas sector, energy effectiveness is becoming an increasingly important topic. Gas turbines are efficient and flexible tools both in electrical and mechanical drive applications as they cope with the multiple energy demand profiles of this sector. Aeroderivative gas turbines boast fast response and fast O&M procedures which fits with the exploitation of hydrocarbon fields. Heavy duty machines are robust and very popular in refinery utilities or as large mechanical drivers. However, it is sometimes desirable to boost GT performances: operators of the Oil & Gas sector may need to increase power output or wish to improve efficiency, especially during part load operation where the latter is degraded. While a number of commercial hardware, service and software products cover these needs, the operators may want to keep their own control on their production tools. To that end resorting to simple thermodynamic considerations enables rule-of-thumb evaluations of the impact of cycle changes on GT performances but this possibility is often unexploited. This joint paper is intended to provide the energy community, especially the engineers of the Oil & Gas sector, with some basic methods for the estimation/anticipation of gas turbine performance changes.

Stationary gas turbines: an exergetic approach to part load operation

“…An alternative measure is to simply heat the inlet air, which also causes a decrease in air mass flow rate Q a and therefore dispenses from changing the VIGV opening angle [63]. The control loop will again compensate this decrease in air flow by increasing of TRIT to keep the power output constant, but this time there will be no degradation of compressor efficiency.…”