Combustion, Fuels and Emissions for Industrial Gas Turbines
It is important that gas turbines used in Oil & Gas applications can burn a wide variety of fuels with the minimum impact on the environment or economics. Many types of gaseous and liquid fuels that can be used in Gas Turbines are discussed, as will be the two basic types of combustion system employed – ‘conventional’ and ‘Dry Low Emissions’ – along with the flexibility of these systems to accept different types of fuel. Some of the common contaminants found in fuels are discussed along with the impact these have on the operability and maintenance of industrial and aero-derivative gas turbines. Topics include: Types of gas turbines Types of exhaust emissions regulated Conventional combustion systems Dry Low (Pre-mixed) emissions combustion systems Fuel quality requirements ‘Pipeline’ quality Natural Gas fuels Premium liquid fuels (diesel, kerosene) Wellhead Gases as a Gas Turbine Fuel Liquified Natural Gas (LNG) Biogas fuels Refinery and process off gases Syngas Natural Gas Liquids and LPG fuels Crude Oil Operational impact of contaminants Water in fuel Storing fuels correctly
Preferential Vaporization Potential of Crude Oils and its Impact on Flame Flashback Behaviors
............................................................................................................................ iv List of Tables ................................................................................................................... viii List of Figures .................................................................................................................... ix List of symbols .................................................................................................................. xii List of Abbreviations ....................................................................................................... xiii Chapter 1: Introduction ........................................................................................................1 1.1 Global Energy Sources ...........................................................................................1 1.2 Crude Oil Characterizations by API and Sulfur Content ........................................5 1.3 Crude Oil Combustion Characteristics in Literature Review .................................8 1.4 Hydrocarbon Fuels Studies Relevant to Gas Turbine Combustors ........................9 Chapter 2: Experimental Methodology ..............................................................................16 2.1 Distillation Apparatus ...........................................................................................16 2.2 Ignition Quality Tester (IQT)................................................................................18 2.3 Nuclear Magnetic Resonance (NMR) ...................................................................20 2.4 Phase Doppler Particle Analyzer (PDPA) ............................................................21 2.5 Spray Burner .........................................................................................................23
Predictions of the flow field and local gas composition in gas turbine combustors
A mathematical model for calculating the three-dimensional flow, gas composition and temperature fields in gas-turbine combustion chambers is described. The model makes use of the density-weighted average forms of the governing conservation equations with the two equation k -e model for turbulent transport. The chemical reactions associated with heat release are assumed to be fast and fluctuations in scalar properties accounted for by use of a β-probability density function (p.d.f.). For liquid spray fuelled combustors the droplet concentration field is described via an equation for the p.d.f. for droplet size. For a propane fuelled model gas turbine combustor the method yields calculated fields of gas composition and pollutants (NO, CO and UHC) which are in good overall agreement with measured values.