Gas Turbines Flashcards
What hazard exists when handling high temperature insulation?
Asbestos
High temperature insulation is often made of asbestos.
This should only be handled by trained personnel.
True or false: Gas turbines are constant flow internal combustion engines.
True
This is done to add heat to a gas which in then sent through a turbine to drive a turbine shaft.
What thing has the main effect on efficiency inside of a gas turbine?
The temperature to which the air can be raised.
To maximize efficiency, you must operate gas turbines at the maximum possible temperatures without harming the machine.
True or false: To maximize efficiency, you must operate gas turbines at the maximum possible temperatures without harming the machine.
True
The more the gases expand (due to temperature) the better the power and efficiency of the turbine.
What does the power rating of a gas turbine depend on?
The mass of hot gas flowing through the turbine blades per unit time
The more air passing by, the greater the power rating.
What effect does cold air have on the power rating of a gas turbine?
Cold air = power rating ↑
Cold air is more dense.
This has to due with the power rating being based off the mass of air passing by the turbine blades per unit of time ⟶ the denser the air (more mass per volume), the more air is passing by.
What is regeneration on a gas turbine?
When some of the exhaust heat is used to heat the air of combustion.
What is cogeneration of a gas turbine?
When exhaust heat is used to generate steam for power generation or other plant processes.
What is the advantage of an external combustion chamber on a gas turbine?
Allows for the use of a wider range of fuels.
Also makes it easier for the addition of regeneration and cogeneration.
What conditions would create the best efficiency for a gas turbine?
Cold intake air and a high turbine operating temperatures.
What are two air conditions improve a gas turbines efficiency?
- Dense air entering the compressor inlet
- High temperature air entering the turbine
This type of gas turbine shaft type has one shaft directly connected to the compressor rotor.
Single shaft type
These are very common and are good for single speed operation.
This type of gas turbine shaft arrangement is very common and good for single speed operation.
Single shaft type
What component needs to be added to a gas turbine single shaft arrangement in order for rotary output power to be harnessed?
A speed reducer
This type of gas turbine shaft type consists of two shafts, with one shaft connected to the compressor and the other connected to the gas generation turbine.
Split shaft type
True or false: Split shaft gas turbines are not suitable for variable speed operations.
False
True or false: Split shaft gas turbine speed can be reduced to improve fuel economy.
True
On a gas turbine running a split shaft arrangement, what direction would the output of the power turbine rotate in relation to the gas-generating turbine?
In the opposite direction.
This type of gas turbine shaft consists on one shaft running inside the other, with two separate compressors and two separate turbines.
Twin spool shaft type
The two sections are split into the high-pressue compressor and turbine and the low-pressure compressor and turbine.
What are the two sections of a gas turbine with a split shaft type?
- High-pressure (HP) compressor and HP turbine
- Low-pressure (LP) compressor and LP turbine
These can often be connected to a twin spool gas generation section with a split shaft type power section.
The gas generation section of a gas turbine brings in air from the 1.________ to mix with fuel in the 2.________ ________ to create hot expanding gases that can be harnessed.
- Compressor
- Combustion chamber
These are the two main sections of the gas generation section of a gas turbine.
What are the two main sections of the gas generation section of a gas turbine?
- Compressor(s)
- Combustion chamber(s)
The gas turbine brings in air from the compressor to mix with fuel in the combustion chamber to create hot expanding gases that can be harnessed.
What are the two main sections of a gas turbine?
- Gas generation section
- Power section
This section of a gas turbine brings air in from the compressor to mix with fuel in the combustion chamber to create hot expanding gases that can be harnessed.
Gas generation section
The two main parts of this section are the compressor(s) and the combustion chamber(s).