3B2 E2.5 C4 Review

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What is the primary function of the compressor section in a gas turbine?

To generate steam for heating purposes

To supply high-pressure air for combustion and mass flow (correct)

To convert the energy created by hot gases into rotational power

To burn fuel and produce hot combustion gases

What is the approximate temperature of the air after compression in a gas turbine?

1500°C

650°C (correct)

1000°C

200°C

What is the purpose of the dilution air in the combustion chamber?

To increase the flame temperature

To reduce the pressure in the combustion chamber

To provide fuel for combustion

To cool the outside of the inner combustion chamber (correct)

What happens to the pressure of the gases as they enter the power turbine?

It decreases significantly Signup and view all the answers

What is the primary purpose of the combustion chamber in a gas turbine?

To burn fuel and produce hot combustion gases Signup and view all the answers

What is the purpose of the power turbine in a gas turbine?

To convert the energy created by hot gases into rotational power Signup and view all the answers

What is a major drawback of adding intercoolers, regenerators, and/or reheaters to a gas turbine?

Additional cost and complexity Signup and view all the answers

What is a characteristic of aero-derivative gas turbines?

Low weight and easily maintained Signup and view all the answers

What is an advantage of heavy-duty gas turbines over aero-derivative gas turbines?

Longer intervals between overhauls Signup and view all the answers

What is a common use of gas turbines in industrial applications?

Driving electric power generators Signup and view all the answers

What is the purpose of a power turbine in an aero-derivative gas turbine?

To drive a generator Signup and view all the answers

What is a characteristic of base loading in power generation?

Producing power on a continuous basis Signup and view all the answers

What is an advantage of aero-derivative gas turbines in certain applications?

Fast starting and low weight Signup and view all the answers

What is a difference between aero-derivative and heavy-duty gas turbines?

Weight and size Signup and view all the answers

What is the purpose of external combustors in heavy-duty gas turbines?

To allow for inter-cooling and regeneration Signup and view all the answers

What is one advantage of using gas turbines in offshore applications?

They are lightweight and have a high power-to-weight ratio Signup and view all the answers

Why are gas turbines not usually suitable for low-power applications?

Their efficiency decreases at lower loads Signup and view all the answers

Which of the following is NOT a reason for the high manufacturing costs of gas turbines?

They have a simple design Signup and view all the answers

Which type of fuel can be used in gas turbines?

Liquid and gaseous fuels Signup and view all the answers

Why is the ability to start rapidly an important advantage for gas turbines in backup power generation?

It increases their availability and reliability Signup and view all the answers

What is one disadvantage of gas turbines compared to other types of internal combustion engines?

They have a slow response to changes in load demand Signup and view all the answers

In comparison to other internal combustion engines, why is a gas turbine considered less suitable for low-power applications?

The efficiency of gas turbines decreases at lower loads. Signup and view all the answers

Why are gas turbines especially suitable for offshore applications?

They have a high power to weight ratio. Signup and view all the answers

What is a significant disadvantage of gas turbines compared to other internal combustion engines?

Gas turbines have high manufacturing costs. Signup and view all the answers

What characteristic of gas turbines makes them less responsive to changes in load demand compared to other internal combustion engines?

Slower speed at which they change speed Signup and view all the answers

Why is the ability to start rapidly essential for gas turbines in backup power generation?

To minimize outage time by quick replacement Signup and view all the answers

What is the primary reason for gas turbines being less suitable for low-power applications?

Decreased efficiency at lower loads Signup and view all the answers

What is the purpose of the combustion section in a gas turbine?

To convert the hot combustion gases into mechanical energy Signup and view all the answers

Why does the temperature of the air increase during compression in a gas turbine?

As a result of the compression process itself Signup and view all the answers

What is the function of the dilution air in a gas turbine combustion chamber?

To aid in the cooling of the inner combustion chamber Signup and view all the answers

Why are the pressures and temperatures quoted in the text only approximations?

Due to variability in machine design and size Signup and view all the answers

What happens to the temperature of the gases as they pass through the power turbine in a gas turbine?

The temperature decreases significantly Signup and view all the answers

What drives the external load, such as an electrical generator, in a gas turbine system?

The mechanical energy developed in the power turbine Signup and view all the answers

What is the primary reason why gas turbines are not used in low-power applications?

They are not efficient at low powers Signup and view all the answers

What is the main advantage of using aero-derivative gas turbines in offshore applications?

They are lighter in weight Signup and view all the answers

What is the primary purpose of the combustion gases in a gas turbine?

To drive the power turbine Signup and view all the answers

Which of the following is not a characteristic of heavy-duty gas turbines?

They are lighter in weight Signup and view all the answers

What is the primary purpose of intercoolers, regenerators, and/or reheaters in a gas turbine?

To increase the efficiency of the turbine Signup and view all the answers

What is a common use of gas turbines in industrial applications?

Driving electric power generators Signup and view all the answers

What is an advantage of aero-derivative gas turbines over reciprocating engines of the same power rating?

They are potentially more efficient Signup and view all the answers

What is the primary purpose of the generator in a gas turbine?

To generate electricity Signup and view all the answers

Why are gas turbines used in peak power generation?

To provide power during periods of high demand Signup and view all the answers

In a single shaft gas turbine arrangement, which components are mounted on the same shaft?

Compressor and power turbine Signup and view all the answers

What is the primary purpose of the high-pressure turbine in a dual shaft gas turbine design?

Drive the compressor Signup and view all the answers

Why is a single-shaft gas turbine arrangement mechanically simpler than a two-shaft arrangement?

No shaft connection between turbines Signup and view all the answers

What is the role of a reducing gear in a single shaft gas turbine system?

Align the compressor and power turbine Signup and view all the answers

What is the difference in the connection of the load between the single shaft layouts shown in Figure 5a and Figure 5b?

Load always connected at the power turbine end Signup and view all the answers

What is the primary function of the low-pressure turbine in a dual shaft gas turbine design?

Drive the generator Signup and view all the answers

What is the main advantage of the dual-shaft arrangement in a gas turbine system?

Reducing the size of the starting motor Signup and view all the answers

Why is the open cycle gas turbine system considered simple?

The use of atmospheric air as the working fluid throughout the cycle Signup and view all the answers

What is a major advantage of closed cycle gas turbine systems?

Higher densities of the working fluid and increased power output Signup and view all the answers

Why does the closed cycle gas turbine system require cooling water?

To cool the working fluid after expansion through the power turbine Signup and view all the answers

What is a significant disadvantage of the open cycle compared to the closed cycle gas turbine systems?

Low thermal efficiency due to heat loss to the atmosphere Signup and view all the answers

Which design feature allows closed cycle systems to use higher pressures throughout the cycle?

Enclosing the working fluid within a closed system Signup and view all the answers

What is the primary function of the high-pressure turbine in a dual shaft gas turbine design?

Drive the compressor Signup and view all the answers

Why is the load usually connected at the power turbine end in a single shaft gas turbine arrangement?

To simplify the mechanical setup Signup and view all the answers

What is the primary purpose of having two vertical combustors in a single shaft gas turbine?

Improve combustion efficiency Signup and view all the answers

What is a significant drawback of using a two-shaft gas turbine arrangement compared to a single shaft arrangement?

Complex mechanical setup Signup and view all the answers

In a single shaft gas turbine system, what is the primary role of the reducing gear?

Align the compressor and load shafts Signup and view all the answers

What differentiates the load placement in Figure 5a from Figure 5b in a single shaft gas turbine layout?

Position relation to the compressor Signup and view all the answers

What is the primary advantage of the dual-shaft arrangement in a gas turbine system?

Higher operating flexibility Signup and view all the answers

What is the primary disadvantage of the open cycle gas turbine system?

Low thermal efficiency Signup and view all the answers

In a closed cycle gas turbine system, what is the purpose of the regenerator?

To exchange heat with the hot exhaust gases Signup and view all the answers

What is an advantage of using a closed cycle gas turbine system over an open cycle system?

Higher thermal efficiency Signup and view all the answers

What is a characteristic of the working fluid in a closed cycle gas turbine system?

It is clean and does not cause corrosion Signup and view all the answers

What is a disadvantage of closed cycle gas turbine systems?

Complexity and increased size of the system Signup and view all the answers

What component of a gas turbine installation helps in decreasing the air inlet temperature?

Intake plenum Signup and view all the answers

In colder climates, where might a gas turbine unit be located?

In a building with extra maintenance space Signup and view all the answers

What purpose does the enclosure serve in a gas turbine installation?

Protect from environment Signup and view all the answers

Why does some air intake incorporate special cooling systems?

To decrease the air inlet temperature Signup and view all the answers

What is the primary function of the air intake in a gas turbine installation?

To reduce the noise level Signup and view all the answers

What purpose does the exhaust system serve in a gas turbine installation?

To provide a safe exit for hot exhaust gases Signup and view all the answers

What is the purpose of a waste heat recovery heat exchanger in a gas turbine?

To supply heat to some other process at the overall facility Signup and view all the answers

What is the primary function of the fuel gas system in a gas turbine?

To provide fuel to the combustion section at the proper temperature, pressure, and flow Signup and view all the answers

What is the purpose of a reducing gear in a gas turbine?

To connect the turbine shaft to a driven load Signup and view all the answers

Why are anti-icing systems necessary in some gas turbines?

To eliminate the buildup of ice in very cold climates Signup and view all the answers

What is the purpose of a steam injection system in a gas turbine?

To reduce emissions and/or increase output Signup and view all the answers

What is the purpose of a water wash system in a gas turbine?

To clean compressor blades Signup and view all the answers

What is the primary function of a reducing gear in a gas turbine system?

To adjust the speed of the turbine shaft to match the load Signup and view all the answers

What is the purpose of a steam injection system in a gas turbine?

To increase mass flow and reduce emissions Signup and view all the answers

Why are anti-icing systems important in gas turbines?

To provide heat to eliminate ice buildup in the air intake Signup and view all the answers

What is the role of a water wash system in a gas turbine?

To clean compressor blades Signup and view all the answers

What is the primary function of the lube oil system in a gas turbine?

To lubricate the bearings Signup and view all the answers

Why must both the intake and exhaust operate with the lowest possible pressure drop in a gas turbine system?

To minimize losses in power and efficiency Signup and view all the answers

What is the primary purpose of the intake plenum in a gas turbine installation?

To provide smooth flow into the gas turbine compressor section Signup and view all the answers

What is a common feature of buildings or enclosures that house gas turbines in colder climates?

Extra lay-down space for maintenance Signup and view all the answers

What is the primary purpose of the exhaust system in a gas turbine installation?

To provide a safe exit for the hot exhaust gases Signup and view all the answers

Why do some air intakes incorporate special cooling systems?

To increase the air density Signup and view all the answers

What is a common component of buildings or enclosures that house gas turbines?

Fire detectors Signup and view all the answers

What is a benefit of using gas turbines in colder climates?

Increased air density Signup and view all the answers

What is the primary factor that affects the power rating of a gas turbine?

The temperature and humidity of the intake air Signup and view all the answers

Which of the following methods is most commonly used to improve the efficiency of the basic gas turbine cycle?

Regeneration Signup and view all the answers

How is the thermal efficiency of a gas turbine calculated?

By dividing the rated power by the fuel energy rate Signup and view all the answers

What is the role of the heat exchanger in the regeneration process?

It preheats the air between the compressor and the combustors Signup and view all the answers

What is the maximum efficiency a modern gas turbine can achieve in simple cycle mode?

35% - 40% Signup and view all the answers

What is the primary limitation of the open cycle gas turbine system?

It is less efficient than the closed cycle system Signup and view all the answers

What is the primary advantage of using intercooling in a gas turbine arrangement?

It makes more of the turbine power available to the output load, since isothermal compression takes less work than adiabatic compression. Signup and view all the answers

What is the effect of reheating in a gas turbine plant?

It increases the energy content of the gases and improves the thermal efficiency of the cycle. Signup and view all the answers

What is a benefit of using regeneration combined with intercooling in a gas turbine?

It increases the benefits of intercooling and makes pressure losses less significant. Signup and view all the answers

What type of heat exchanger is used for intercooling in a gas turbine arrangement?

A shell and tube heat exchanger. Signup and view all the answers

What is the purpose of reheating in a gas turbine plant?

To increase the exhaust heat and improve the thermal efficiency of the cycle. Signup and view all the answers

What is a disadvantage of using high-pressure ratio compressors in a gas turbine?

It increases the pressure losses and decreases the overall cycle efficiency. Signup and view all the answers

What is a primary disadvantage of using a high-pressure ratio compressor in a gas turbine system?

Significant losses through the intercooler Signup and view all the answers

How does intercooling affect the specific volume of the air in a gas turbine system?

It reduces the specific volume Signup and view all the answers

What is one of the benefits of combining intercooling with regeneration in a gas turbine setup?

Enhanced thermal efficiency Signup and view all the answers

In a gas turbine arrangement, what is the purpose of reheating the gases between stages?

To increase the energy content of the gases Signup and view all the answers

What drives the steam turbine in many combined cycle or cogeneration systems integrated with gas turbines?

Steam produced from the exhaust heat Signup and view all the answers

Why is utilizing the exhaust heat of a gas turbine important in combined cycle or cogeneration systems?

To improve overall system efficiency Signup and view all the answers

What is the primary reason for the reduced necessity of cycle improvements in modern gas turbines?

Advancements in combined cycle technology Signup and view all the answers

Which cycle improvement method increases the temperature of compressed air before combustion?

Regeneration Signup and view all the answers

What method is used to calculate the fuel energy rate in gas turbines?

Multiplying the fuel flow rate and the fuel heating value Signup and view all the answers

What is the main limitation of using high-pressure ratio compressors in a gas turbine?

Higher compressor discharge temperatures Signup and view all the answers

What is the primary function of intercoolers, regenerators, and/or reheaters in a gas turbine system?

To improve the basic efficiency of the gas turbine cycle Signup and view all the answers

What is the primary advantage of closed cycle gas turbine systems?

No fuel consumption, unlike open cycle systems Signup and view all the answers

What is the purpose of the diffuser in a centrifugal compressor?

To convert air velocity energy to pressure energy Signup and view all the answers

What percentage of the energy provided by fuel does a compressor use in a gas turbine?

Up to 65% Signup and view all the answers

In what direction does the air move inside an axial compressor?

Along the shaft Signup and view all the answers

What is the main advantage of a multi-stage centrifugal compressor over a single-stage one?

Higher pressure ratio Signup and view all the answers

What effect do fixed blades between rows of moving blades have on the air inside an axial compressor?

Slow the air down and raise the pressure Signup and view all the answers

Why are axial compressors preferred in the majority of large gas turbines?

Achieve higher compression ratios Signup and view all the answers

What percentage of the energy provided by the fuel is used by the compressor in a gas turbine?

Up to 65% Signup and view all the answers

What is the main difference between centrifugal and axial compressors?

Centrifugal compressors move the air radially, while axial compressors move the air axially. Signup and view all the answers

What is the purpose of the diffuser in a centrifugal compressor?

To convert the velocity energy to pressure energy Signup and view all the answers

Why are axial compressors preferred in the majority of large gas turbines?

Because they are more efficient and structurally sound Signup and view all the answers

What is the primary advantage of centrifugal compressors?

Simplicity and strength Signup and view all the answers

How do fixed blades affect the air inside an axial compressor?

They decelerate the air and raise the pressure Signup and view all the answers

What is the primary purpose of dilution air in the combustion chamber of a gas turbine?

To reduce the combustion temperature and impurities Signup and view all the answers

What type of combustor uses a single concentric flame tube?

Annular Combustor Signup and view all the answers

What percentage of the air entering the combustor is mixed with the fuel in the flame tube as combustion air?

20% Signup and view all the answers

What is the main function of the combustion chamber in a gas turbine?

To heat the compressed air before it enters the power turbine Signup and view all the answers

What is the role of the cooling air in the combustor?

It flows along the outside of the flame tube to cool the combustor Signup and view all the answers

What is the main advantage of an annular combustor design?

It is the most efficient use of the space available to the airflow Signup and view all the answers

What is the main difference between can-annular and annular combustors?

The main difference is in the way air is distributed to the combustor cans. Signup and view all the answers

What purpose do the interconnecting pipes serve in a can-annular combustor?

They carry the flame from one combustor to the other during the starting sequence. Signup and view all the answers

How many combustors in a can-annular arrangement have igniter elements?

Two combustors have igniter elements. Signup and view all the answers

What is the purpose of the outer casing in a can-annular combustor?

It allows for relative expansion of the combustor. Signup and view all the answers

What is the main function of the radial pins in a can-annular combustor?

They allow for relative expansion of the combustor. Signup and view all the answers

What is a significant disadvantage of the can combustor design in gas turbines?

Requires multiple igniters and fuel lines Signup and view all the answers

What is a unique feature of reverse flow can combustors in gas turbines?

Air flows to the end (top) of the combustor and then back toward the outlet Signup and view all the answers

Which statement best describes the behavior of air in the external casing of a single can combustor?

It absorbs heat, which improves combustion Signup and view all the answers

In heavy-duty industrial machines, where are the cans of a can combustor typically arranged?

Externally in a horizontal arrangement around the casing Signup and view all the answers

What is a significant difference between can-annular and annular combustors in gas turbines?

Annular combustors are more efficient in space utilization Signup and view all the answers

What is the primary role of dilution air in a gas turbine combustor?

To cool the combustion gases Signup and view all the answers

What is the main benefit of using aero-derivative gas turbines in offshore applications?

Improved structural strength and easier maintenance access Signup and view all the answers

Which of the following statements best describes intercooling in a gas turbine system?

Increases the specific volume of the air Signup and view all the answers

What is the purpose of a power turbine in an aero-derivative gas turbine?

To provide rotational energy for powering other equipment Signup and view all the answers

Which of the following is a difference between aero-derivative and heavy-duty gas turbines?

Heavy-duty gas turbines have a more complex design Signup and view all the answers

How does a combustor in a gas turbine achieve heating of the compressed air?

By heating the compressed air before it enters the power turbine Signup and view all the answers

What is the purpose of the cooling air in a gas turbine combustor?

To cool the power turbine blades Signup and view all the answers

What is the temperature range of the combustion flame in a gas turbine combustor?

1500 to 2000°C Signup and view all the answers

Why do some parts of the cooling air re-enter the flame tube in a gas turbine combustor?

To dilute the mixture in the flame tube Signup and view all the answers

What design is the most efficient use of space available to airflow in a gas turbine combustor?

Annular Combustor Signup and view all the answers

What is the main benefit of using single concentric flame 'tube' in an annular combustor design?

Efficient use of available space Signup and view all the answers

What is a unique advantage of annular combustion chambers in aircraft engines?

Compactness Signup and view all the answers

Which aspect of the can combustor design minimizes problems associated with non-uniform outlet temperatures?

External mounting Signup and view all the answers

In a can combustor system, what is the purpose of the swirl plate?

To mix air and fuel Signup and view all the answers

How is the air flow direction described in an external reverse flow can combustor design?

Inward towards the turbine Signup and view all the answers

What contributes to the minimization of flow resistance in an annular combustion chamber?

Even distribution of combustion Signup and view all the answers

How is the combustion air supplied to the can combustor in the external reverse flow design?

From the compressor outlet Signup and view all the answers

What is a key disadvantage of can combustors in comparison to annular combustors?

Not the most efficient use of space Signup and view all the answers

What distinguishes the airflow path in a straight-through can combustor?

Exits at the inlet end Signup and view all the answers

How do air crossover tubes benefit multiple can combustors in a system?

Help maintain equal operating conditions Signup and view all the answers

What allows for easier maintenance access and greater strength in some external can combustor designs?

External mounting angle Signup and view all the answers

How is air distributed to the combustor cans in a can-annular combustor arrangement?

From a common annular space between inner and outer air casings through scoops and holes Signup and view all the answers

What is the primary function of the radial pins in a can-annular combustor?

To allow relative expansion between the inner chamber and the outer casing Signup and view all the answers

What role do interconnecting pipes play in a can-annular combustor arrangement?

To ensure uniform combustion conditions and carry the flame from one combustor to another during starting sequence Signup and view all the answers

Which statement best describes the cooling air distribution in a can-annular combustor?

The cooling air is supplied through holes in the combustors Signup and view all the answers

What is the significance of having only two combustors with igniter elements in a can-annular combustor?

To maintain combustion stability by using a limited number of ignition elements Signup and view all the answers

What type of material are conventional gas turbine nozzles cast with?

Nickel-based super alloys Signup and view all the answers

Why are gas turbine blades usually replaced at fixed intervals?

To avoid catastrophic blade failure Signup and view all the answers

What is the main function of blade cooling in gas turbines?

To decrease metal temperature and increase blade life Signup and view all the answers

Which type of gas turbine blade cooling often uses air-circulation?

Air-cooled blades Signup and view all the answers

What is the greatest challenge in gas turbine materials?

Managing materials in the turbine nozzles and blades Signup and view all the answers

Why do gas turbine rotors withstand high stresses?

Because of high gas temperatures and rotational speeds Signup and view all the answers

What is the primary purpose of the power turbine in a gas turbine system?

Provide mechanical power for the generator Signup and view all the answers

In axial-flow turbines, what is the function of the nozzles?

Increase pressure and temperature Signup and view all the answers

What distinguishes power turbines from compressors in a gas turbine system?

Have a higher number of stages Signup and view all the answers

Which statement is true regarding power turbines operating at high temperatures?

Undergo large rotational stresses Signup and view all the answers

What is the main function of the moving blades in the axial-flow turbine?

Decrease pressure and temperature Signup and view all the answers

How does an impulse turbine different from a reaction turbine in terms of nozzle action?

Impulse turbines convert pressure energy into velocity energy Signup and view all the answers

What is the primary reason for incorporating complicated cooling passages in turbine nozzles and blades?

To reduce metal temperature and increase life Signup and view all the answers

What is the typical material used to make turbine rotors?

Heat resisting steel Signup and view all the answers

What is the phenomenon that occurs in metals at very high temperatures and stresses, causing them to stretch and weaken?

Creep Signup and view all the answers

What is the purpose of replacing turbine blades at fixed intervals?

To prevent catastrophic failure due to creep Signup and view all the answers

What is the advantage of using ceramic components in turbine blades?

They allow for a significant increase in firing temperatures Signup and view all the answers

What is the material used to cast conventional nozzles?

Special nickel-based super alloys Signup and view all the answers

What percentage of the power from the hot gases is used to drive the compressor?

Up to 65% Signup and view all the answers

What is the primary function of the nozzles in an axial-flow turbine?

To increase the velocity of the hot gases Signup and view all the answers

What is the primary difference between impulse and reaction turbines?

The way nozzles convert energy Signup and view all the answers

What is the primary reason for the high blade loads in power turbines?

High velocity of the hot gases Signup and view all the answers

What is a characteristic of the stages in an axial-flow turbine?

A row of rotating and stationary blades Signup and view all the answers

What is the purpose of the rotating blades in an axial-flow turbine?

To extract power with a further drop in pressure and temperature Signup and view all the answers

What is the purpose of the acceleration fuel flow schedule in a gas turbine control system?

To override the governor error signal during acceleration Signup and view all the answers

What is monitored in a gas turbine control system to detect excessive vibration?

Accelerometers or eddy-current displacement probes Signup and view all the answers

What is the purpose of the automatic emergency trip system in a gas turbine control system?

To close the main fuel shutoff valve in case of emergency Signup and view all the answers

What is the purpose of the operator interface in a gas turbine control system?

To allow the operator to startup, shutdown, or modify the control system logic Signup and view all the answers

What is protected against by the protective devices in a gas turbine control system?

Power turbine overspeed, excessive vibration, and other conditions Signup and view all the answers

What is the purpose of the instrumentation in a gas turbine control system?

To monitor various parameters of the gas turbine Signup and view all the answers

What type of fuel system does the dual-shaft gas turbine control system configuration vary according to?

Gaseous fuel system Signup and view all the answers

Which component in the system establishes a speed reference setting in the reset mechanism?

Loading station Signup and view all the answers

What is the purpose of the reset mechanism in the governor?

To control the engine fuel flow Signup and view all the answers

What role do override trims play in the governor reset mechanism?

They protect the gas producer from over temperature and overspeed Signup and view all the answers

What is the function of the metering valve positioner in the system?

To reposition the fuel metering valve until the error is eliminated Signup and view all the answers

What is the role of the pressure regulator in the gas fired system?

To supply pressurized gas to the gas supply line Signup and view all the answers

What parameter is continuously monitored and controlled for a gas turbine using vibration sensors?

Bearing temperatures Signup and view all the answers

In a gas turbine control system, acceleration fuel flow schedule is based on the rise in _____________.

Compressor outlet pressure Signup and view all the answers

What is the main purpose of the operator interface in a gas turbine control system?

To startup or shutdown the gas turbine Signup and view all the answers

What system is automatically initiated when there is an increase in demand for power in a gas turbine setup?

Backup power generation unit Signup and view all the answers

Which of the following would be a cause for the automatic shutdown of a gas turbine due to protection systems?

Exhaust gas temperature exceeding the maximum limit Signup and view all the answers

What is the primary role of an emergency trip system in a gas turbine control setup?

To close the main fuel shutoff valve under specific conditions Signup and view all the answers

What is the function of the reset mechanism in the governor of a gas turbine control system?

It determines the position of the fuel metering valve and controls the engine fuel flow. Signup and view all the answers

What is the primary purpose of the fuel metering valve in a gas turbine control system?

It regulates the supply of pressurized fuel to the combustors. Signup and view all the answers

How does the governor system respond to changes in engine speed in a gas turbine control system?

It maintains a constant engine speed by adjusting the fuel flow to the burners. Signup and view all the answers

What is the role of the pressure regulator in the gas fired system of a gas turbine?

It ensures the fuel pressure remains constant regardless of demand. Signup and view all the answers

What is the purpose of the override trims applied on the governor reset mechanism in a gas turbine control system?

They produce an artificial error signal until an adverse condition is overcome. Signup and view all the answers

What is the effect of an error signal in the governor of a gas turbine control system?

It repositions the fuel metering valve to maintain a constant engine speed. Signup and view all the answers

What is the primary factor affecting the efficiency and power output of a gas turbine?

The compression ratio across the compressor Signup and view all the answers

Why is an increase in turbine inlet temperature beneficial for gas turbine efficiency?

Allows more work to be done with the same amount of air Signup and view all the answers

In gas turbine design, what is the main focus in order to achieve high efficiency in the cycle?

Improving combustion and turbine materials Signup and view all the answers

What is a key consideration when determining the maximum power achievable by a gas turbine?

The expected life of hot gas path components Signup and view all the answers

When might a user be inclined to accept higher maintenance costs in a gas turbine system?

For peak power generation during short periods Signup and view all the answers

Why is operating at maximum power not preferred for base load operation in a gas turbine system?

To lower the risk of failure Signup and view all the answers

What is the unit of measurement for heat rate in a gas turbine?

MJ/kWh Signup and view all the answers

What is the effect of decreasing inlet air temperature on the power produced by a gas turbine?

Power output increases Signup and view all the answers

What is the power output of the gas turbine at an ambient air temperature of 45°C?

6600 kW Signup and view all the answers

What is the relationship between the power produced by a gas turbine and the mass airflow?

Power is directly proportional to mass airflow Signup and view all the answers

What is the purpose of using heat exchangers in gas turbines?

To increase power output Signup and view all the answers

What is the rated power at standard conditions of 15°C?

9500 kW Signup and view all the answers

What is the primary factor in determining efficiency and power in a gas turbine?

Turbine inlet temperature Signup and view all the answers

What is the typical efficiency range of a simple cycle gas turbine?

30-40% Signup and view all the answers

What is the maximum power that can be achieved in a gas turbine a function of?

Life expected of the hot gas path components Signup and view all the answers

What is the primary advantage of combined cycle applications in gas turbine plants?

Total efficiency exceeding 60% Signup and view all the answers

Why is maximum power not desirable for base load operation?

It increases the risk of failure and maintenance costs Signup and view all the answers

What is the tradeoff often used for peak power generation?

Higher maintenance costs for increased power output Signup and view all the answers

What is the primary factor that affects the power output of a gas turbine?

Inlet air temperature Signup and view all the answers

What is the unit of measurement for heat rate input in a gas turbine?

MJ/kWh Signup and view all the answers

At what inlet air temperature is the power output of the gas turbine approximately 12 000 kW?

-30°C Signup and view all the answers

What is the effect of decreasing inlet air temperature on the mass airflow through the engine?

It increases Signup and view all the answers

What is the relationship between the power produced by a gas turbine and the mass flow?

The power is directly proportional to the mass flow Signup and view all the answers

What is the rated power of the gas turbine at standard conditions of 15°C?

9500 kW Signup and view all the answers

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Questions and Answers

What is the primary function of the compressor section in a gas turbine?

What is the approximate temperature of the air after compression in a gas turbine?

What is the purpose of the dilution air in the combustion chamber?

What happens to the pressure of the gases as they enter the power turbine?

What is the primary purpose of the combustion chamber in a gas turbine?

What is the purpose of the power turbine in a gas turbine?

What is a major drawback of adding intercoolers, regenerators, and/or reheaters to a gas turbine?

What is a characteristic of aero-derivative gas turbines?

What is an advantage of heavy-duty gas turbines over aero-derivative gas turbines?

What is a common use of gas turbines in industrial applications?

What is the purpose of a power turbine in an aero-derivative gas turbine?

What is a characteristic of base loading in power generation?

What is an advantage of aero-derivative gas turbines in certain applications?

What is a difference between aero-derivative and heavy-duty gas turbines?

What is the purpose of external combustors in heavy-duty gas turbines?

What is one advantage of using gas turbines in offshore applications?

Why are gas turbines not usually suitable for low-power applications?

Which of the following is NOT a reason for the high manufacturing costs of gas turbines?

Which type of fuel can be used in gas turbines?

Why is the ability to start rapidly an important advantage for gas turbines in backup power generation?

What is one disadvantage of gas turbines compared to other types of internal combustion engines?

In comparison to other internal combustion engines, why is a gas turbine considered less suitable for low-power applications?

Why are gas turbines especially suitable for offshore applications?

What is a significant disadvantage of gas turbines compared to other internal combustion engines?

What characteristic of gas turbines makes them less responsive to changes in load demand compared to other internal combustion engines?

Why is the ability to start rapidly essential for gas turbines in backup power generation?

What is the primary reason for gas turbines being less suitable for low-power applications?

What is the purpose of the combustion section in a gas turbine?

Why does the temperature of the air increase during compression in a gas turbine?

What is the function of the dilution air in a gas turbine combustion chamber?

Why are the pressures and temperatures quoted in the text only approximations?

What happens to the temperature of the gases as they pass through the power turbine in a gas turbine?

What drives the external load, such as an electrical generator, in a gas turbine system?

What is the primary reason why gas turbines are not used in low-power applications?

What is the main advantage of using aero-derivative gas turbines in offshore applications?

What is the primary purpose of the combustion gases in a gas turbine?

Which of the following is not a characteristic of heavy-duty gas turbines?

What is the primary purpose of intercoolers, regenerators, and/or reheaters in a gas turbine?

What is a common use of gas turbines in industrial applications?

What is an advantage of aero-derivative gas turbines over reciprocating engines of the same power rating?

What is the primary purpose of the generator in a gas turbine?

Why are gas turbines used in peak power generation?

In a single shaft gas turbine arrangement, which components are mounted on the same shaft?

What is the primary purpose of the high-pressure turbine in a dual shaft gas turbine design?

Why is a single-shaft gas turbine arrangement mechanically simpler than a two-shaft arrangement?

What is the role of a reducing gear in a single shaft gas turbine system?

What is the difference in the connection of the load between the single shaft layouts shown in Figure 5a and Figure 5b?

What is the primary function of the low-pressure turbine in a dual shaft gas turbine design?

What is the main advantage of the dual-shaft arrangement in a gas turbine system?

Why is the open cycle gas turbine system considered simple?

What is a major advantage of closed cycle gas turbine systems?

Why does the closed cycle gas turbine system require cooling water?

What is a significant disadvantage of the open cycle compared to the closed cycle gas turbine systems?

Which design feature allows closed cycle systems to use higher pressures throughout the cycle?

What is the primary function of the high-pressure turbine in a dual shaft gas turbine design?

Why is the load usually connected at the power turbine end in a single shaft gas turbine arrangement?

What is the primary purpose of having two vertical combustors in a single shaft gas turbine?

What is a significant drawback of using a two-shaft gas turbine arrangement compared to a single shaft arrangement?

In a single shaft gas turbine system, what is the primary role of the reducing gear?

What differentiates the load placement in Figure 5a from Figure 5b in a single shaft gas turbine layout?

What is the primary advantage of the dual-shaft arrangement in a gas turbine system?

What is the primary disadvantage of the open cycle gas turbine system?

In a closed cycle gas turbine system, what is the purpose of the regenerator?

What is an advantage of using a closed cycle gas turbine system over an open cycle system?

What is a characteristic of the working fluid in a closed cycle gas turbine system?

What is a disadvantage of closed cycle gas turbine systems?

What component of a gas turbine installation helps in decreasing the air inlet temperature?

In colder climates, where might a gas turbine unit be located?

What purpose does the enclosure serve in a gas turbine installation?

Why does some air intake incorporate special cooling systems?

What is the primary function of the air intake in a gas turbine installation?

What purpose does the exhaust system serve in a gas turbine installation?

What is the purpose of a waste heat recovery heat exchanger in a gas turbine?

What is the primary function of the fuel gas system in a gas turbine?

What is the purpose of a reducing gear in a gas turbine?

Why are anti-icing systems necessary in some gas turbines?

What is the purpose of a steam injection system in a gas turbine?