Liquid Fuel Developments on the SGT-500 Industrial Gas Turbine to maximise Fuel Flexibility

摘要

While ‘pipeline quality’ natural gas is the current fossil fuel of choice for power generation, it is not universally available, forcing some regions of the World, particularly those in more remote areas, to rely on liquid fuels to provide the energy required for industrial and domestic customers. While diesel is a common alternative fuel when natural gas is not available, it is also an expensive alternative. To provide electricity and heat to households and industries at a competitive cost without relying on heavy Government subsidies, it is necessary to look at using lower cost liquid fuels such as Heavy Fuel Oil or even treated crude oil, or the lower value and ‘waste’ fuels from the Oil & Gas industry such as Residual Oils from the refining processes, or condensates and LPGs produced during natural gas processing. However, the composition and contaminants in these types of low cost liquid fuels present technical challenges for gas turbines. This paper looks at the initial design features of SGT-500 gas turbine that made it suitable for Heavy Fuel Oils up to IF180, including the fuel pre-treatment systems, and goes on to discuss recent uprates and tests that have demonstrated its ability to use high viscosity liquid fuels of over 1000 cSt @ 50°C. It also describes why these features make the SGT-500 an option to diesel engines for cogeneration applications where the high exhaust gas temperatures can be utilized to produce process heat and maximise overall energy efficiency while minimising emissions to atmosphere.