Construction Of The Gas Turbine Ge 7fa.docx

Construction of the Gas Turbine GE 7FA

I.

Compressor

The compressor of the GE 7FA gas turbine has a split construction in which the parts are easy to assemble and disassemble. As shown on the figure above, it consists of 14 stages which are modeled for a high flow rate and allows greater output. Its airfoils use aerodynamic, three-dimensional shape to improve the efficiency. The first three stages is constructed of variable stator vanes which give a wider operating envelope for the gas turbine. The rotor blades and wheels have a dovetail circumference that allows the blades to be removed without having to remove the rotor from the casing. The casing itself was built to match the rotor and the combustor (DLN2.6) interface, it has an advance Blade Health Monitoring (BHM) system for the first 3 stages. II.

Combustion Chamber The combustor used in this gas turbine is the DLN2.6 combustor. It has more than 15 million hours operational experience. From the figure on the right, the combustor has a construction of a can type. This type of combustor has an

III.

advantage that it can easily be added and removed, making it easier to control and maintain. More advantages of the DLN2.6is that it can turndown gas turbine load to less than 36%, improved cooling, and produces low NOX at high Tfire. Turbine The features of the turbine section include:  Three-dimensional, aerodynamic airfoil shapes which improve efficiency.  Improved clearance for higher efficiency.  Axial type with shrouded tip