Showing posts with label FUEL SPRAY NOZZLES. Show all posts
Showing posts with label FUEL SPRAY NOZZLES. Show all posts

Wednesday, February 22, 2012

Fuel requirements


Fuel requirements

107. In general, a gas turbine fuel should have the following qualities:

(1)  Be 'pumpable' and flow easily under all operating conditions.
(2) Permit engine starting at all ground  conditions and give satisfactory flight relighting characteristics.
(3)  Give efficient combustion at all conditions.
(4)  Have as high a calorific value as possible.
(5)  Produce minimal harmful effects on the combustion system or the turbine blades.
(6)  Produce minimal corrosive effects on the fuel system components.
(7) Provide adequate lubrication for the moving parts of the fuel system.
(8)  Reduce fire hazards to a minimum.

108. The pumping qualities of the fuel depend upon its viscosity or thickness, which is related to fuel temperature, Fuel must be satisfactory down to approximately -50 deg. C. As the fuel temperature falls, ice crystals may form to cause blockage of the fuel filter or the orifices in the fuel system. Fuel heating and anti-icing additives are available to alleviate this problem.

FUEL SPRAY NOZZLES


FUEL SPRAY NOZZLES
89. The final components of the fuel system are the fuel spray nozzles, which have as their essential function the task of atomizing or vaporizing the fuel to ensure its rapid burning. The difficulties involved in this process can be readily appreciated when one considers the velocity of the air stream from the compressor and the short length of combustion system (Part 4) in which the burning must be completed.