Fuels for Gas Turbine Power Plants
Important properties of the fuel needed for gas turbine application are volatility, high calorific value, self lubrication property and its availability at low cost having no suspended impurities.
Volatility of fuel should be such that it provides case of starting at low temperatures and burn with high combustion efficiency. Highly volatile fuels are not desirable for gas turbine applications since they are susceptible to fire and may cause vapour lock.
Fuels should have high calorific value and provide certain amount of lubrication to frictional surfaces of fuel pumps.
The fuels should be available easily at low cost.
Various types of fuels used for gas turbine are :
- Natural gas for industrial application.
- High grade gasoline for aircraft applications.
- Kerosene (Dodecane).
- Heavy oils.
- Blast furnace gas of a steel mill.
- Residual oils as the residue of crude oil.
Since residual oils are highly viscous, they need to be heated before supplied to atomiser. The other related problems with use of residual oil as fuel are formation of tar when overheated, clogging of system and high carbon deposits on combustion chamber, corrosion of turbine blades etc. Usually the use of residual oils is avoided for large power plants.