Combustion Gas Turbines PDF Print E-mail
Written by Norrie   
Wednesday, 13 January 2010 10:12
Article Index
Combustion Gas Turbines
Principles and Operation
The Air Compressor
The Combustion Chamber
The Compressor (HP) Turbine
The Variable-Angle Nozzles Load Turbine
Turbine/Compressor Lube Control Oil System
Turbine Hydraulic Oil Trip System
Turbine Overspeed Trip Mechanisms
Turbine System Details
All Pages


In operating areas where suitable water for steam generation is in short supply and natural gas is plentiful, Combustion Gas Turbines are used to drive other Machines. A Combustion Gas Turbine, like any other internal combustion engine, is a machine which converts the Thermal Energy of burning fuel into useful power which, in turn is converted into Mechanical Energy. Just like a windmill, waterwheel or steam turbine, a combustion gas turbine depends on the flow of fluid for its driving force. The driving fluid in this case, is very high temperature, compressed air. Let us first begin again with our pin-wheel. If we place a running fan in front of the pin-wheel, the air flow from the fan will cause the pin-wheel to rotate. Now, in theory, if we connect the fan to the pin-wheel by a shaft, when the fan is running, the pinwheel is rotating and, through the shaft should rotate the fan. At this point we should be able to switch off the power to the fan and the system will continue to run - the pin-wheel driving the fan and the air from the fan driving the pin-wheel.

In practice, this is not possible due to friction and other power losses in the system. (Figure. 14) However, if we can add extra energy to the air flow from the fan in sufficient quantity, then this will maintain the pin-wheel rotation which, in turn, will maintain the fan rotation. In (Figure. 15), we have added a combustion chamber between the fan and the pin-wheel. By burning fuel in the combustion chamber, the thermal energy of the air is greatly increased and this increase in energy will maintain the rotation when the fan power is switched off.
Figure. 14


Increasing the Energy of the Air

Figures. 15

Last Updated on Wednesday, 24 February 2010 20:06