Download Mechanical Interview Questions and Answers (Gas Turbine)
What purpose does the transition component serve?
The hot gases are directed from the liners to the first stage nozzles by the transition piece.
The size of the turbine buckets increases from the first to the third stage. Why?
The size of the turbine buckets increases from the first to the third stage. Why?
The larger annulus area necessary to handle the gas flow due to the pressure reduction caused
by energy conversion in each stage necessitates increasing the bucket size.
What does the term "wheel space" mean?
What does the term "wheel space" mean?
The wheel space is the area between the turbine wheel with the bucket and the stator that
leads into the main gas stream.
How does air cool the wheel space?
How does air cool the wheel space?
Air travels through the high pressure passage seal at the aft end of the compressor rotor to
cool the first stage front wheel area.
The compressor discharge air that goes through the stage 1 shroud and then secondary inward
through stage 2 nozzles vanes cools the second stage forward wheel space, while cooling air
departure from the exhaust frame cooling circuit cools the third aft wheel area.
What is the purpose of the cooling system for the turbine shell, and why is
it necessary?
What is the purpose of the cooling system for the turbine shell, and why is
it necessary?
Turbine shell cooling is provided by three exhaust frame cooling fans (88TK).
The shrouds and nozzles' axial and radial locations are controlled by the turbine shell. It
calculates turbine clearances and the nozzles' relative position to the turbine buckets. The
position is crucial to the functioning of a gas turbine.
Turbine nozzles serve what purpose? Turbine nozzles direct the expanding hot combustion gas's high-velocity flow against the turbine buckets, causing the rotor to rotate.
Turbine nozzles serve what purpose? Turbine nozzles direct the expanding hot combustion gas's high-velocity flow against the turbine buckets, causing the rotor to rotate.