15.5 Flashcards
Important requirement of combustion
It must be complete , no unburnt fuel leaves the combustion chamber
What important about combustion chamber outlet
Equal temperature distribution, especially at first turbine stage
3 requirements of combustion chamber
Small and light
Dependable cooling system
High operating lifetime
Why do we need a small and light chamber
To save weight
What’s the problem with replacing engine components in the combustion chamber
It’s very time consuming
2 parts of combustion chamber
Casing (can be inner and outer)
Flame tube
What does the casing do
Outer shield that takes air pressure loads and protects external engine parts
What does the housing support
Flame tube and other combustion chamber components (fuel nozzle and igniter plugs)
What does the flame tube do
Control and guides the flame
Made of segments and had lots of holes and slots
Conditions for correct and safe combustion
Correct fuel to air ratio
Air velocity slow enough to make sure combustion is completed inside the chamber
Kerosene air fuel mix ratio
15 parts air 1 part fuel
15:1
What air is used for combustion process
Primary
What % of air is primary from the compressor
20-30%
What part of the chamber does the flame stabilise
Primary zone
3 types of combustion chambers
Can-type
Can-annular
Annular
Where are can-type combustion chambers used
Old gas turbines with centrifugal compressors
Advantage of can-type
Simple and goodstructural strength
Removed and replaced individually
Disadvantage of can-type
Difficult ignition from one chamber to another