Chapter 71- Gas Turbines Flashcards
The three things a gas turbine is considered
*constant flow rotors engine * heat engine * prime mover
List two facts about early gas turbines
* handicapped by lack of metal that withstand high temps * air compressor and turbine had very love efficiency
____ of the power is used for the air compression on a gas turbine
2/3
Output power or ____ depends in _____
Power rating Mass of hot gas
Output increases in a gas turbine when using
Air of maximum density
An example of aero turbine
Jet engine
An open system gas turbine
Air drawn from atmosphere and returned
Air and hot gas are _____ from compressor to turbine
Ducted
Turbine has to be brought up to ___% speed before the fuel is turned on
20-30
The two types of gas turbine
Aero derivative Land based
A simple turbine system has no (3)
*heat exchanger *regenerator *intercooler
A single shaft gas turbine
Has only one shaft. Compressor and turbine are coupled together
What is the majority of gas turbines in industry
Simple Open single shaft
Five advantages of the gas turbine
*higher power to weight ratio *low installed coat *low maintenance and operating cost *minimum cooling water *rapid start up and loading
List four disadvantages of gas turbines
*low mechanical and thermal efficiency *high noise level *limited types of fuel *NOx emissions
Compared to a steam plant and gas turbine is
Smaller and lighter
Absence of reciprocating motion and min wear of moving parts results in
Low maintenance and operating cost
Gas turbines require Minimal cooling water and is ideal for
Areas where water is scarce
What type of fuel does a turbine use
Clean liquid or gaseous fuels
What’s the purpose of regenerators
Improve efficiency by recovering heat
Regenerators are more efficient with
Cold air