Chapter 4 (GAS TURBINE) Flashcards
Brayton Cycle has:
Two isentropic and two constant pressure processes
Brayton cycle cannot be used in reciprocating engines even for same adiabatic compression ratio and work output because:
Large volume of low pressure air cannot be efficiently handled in reciprocating engines
Which cycle is generally used for gas turbine?
Brayton cycle
When r is the compression ratio, the efficiency of Brayton cycle is given by:
1 — 1/r^(k-1)/k
A regenerator in a gas turbine:
Improves thermal efficiency
Which of the following compressors is generally used for gas turbines?
Axial flow type
The constant pressure gas turbine works on the principle of:
Brayton cycle
What type of gas turbine is used in air craft?
Open cycle type
In a gas turbine combined cycle plant, a waste heat boiler is used to:
Recover heat from exhaust gases
Overall efficiency of a gas turbine is:
less than Diesel Cycle efficiency
Which of the following turbine has least weight per bhp developed?
Simple open cycle gas turbine
Which of the following is/are advantage of closer cycle gas turbine over open cycle gas turbine?
all of the above
The range of compression ratio in a gas turbine is:
5 to 8
A constant volume conbustion gas turbine operates on:
Atkinson cycle
Heat exchanger used to provide heat transfer beteeen the exhaust gases and the air prior to its entrance to the combustor
Regenerator
How does the value for work per unit mass flow of air in the compressor and turbine influenced by the addition of a regenerator?
Unchanged
What is the ideal cycle for gas turbine work?
Brayton cycle
Brayton cycle cannot be used in reciprocating engines even for the same adiabatic compression ratio and work output because:
Large volume of low pressure air cannot be efficient handled in reciprocating engines
In order to increase the gas velocity gas turbines generally have fixed nozzles. This is to allow the:
Expansion of gases
Combustion turbines or gas turbines are the preferred combustion engines in application much above
10 MW
Large units gas turbine regularly operate:
in 100 to 200 MW range
Small units gas turbune operates below
30 MW
Heavy duty gas turbines typically have:
Single shaft
Which of the following is basically a jet engine that exhausts into a turbine generator?
Aeroderivative gas turbine
Most aeroderivative combustion turbine produce less than:
40 MW
The compression ratio based on pressures in the compression stage in a gas turbine is typically:
11 to 16
The compression ratio based on pressures of heavy duty gas turbine is in the range of
14 to 15
Aeroderivative combustion turbine have higher compression ratios typically:
19 to 21
Most heavy duty conbustion turbines have how many compression stages?
16 to 18
The temperature of the gas entering the expander section is typically:
1200 C to 1290 C
