WorksheetsPIPE ELEMENTS 5.1
Total questions: 98
Worksheet time: 49mins
Which type of turbine is used for low head and high flow?
Pelton wheel
Francis turbine
Kaplan turbine
Impulse turbine
Which method reduces turbine gland leakage?
Poor lubrication
High condenser pressure
Gland sealing system
Sealing
Which formula defines water power?
n gh
PV
ρgQH
V2/(2g)
Which cause produces knocking in a diesel?
Early spark
Abnormal rapid pressure rise from fuel autoignition delay
Cold intake
Low compression ratio
What does the Biot number being much less than 1 indicate?
Heat conduction dominates
Radiation dominates
Lumped system analysis is valid
Convection resistance dominates
Which cycle governs the topping cycle in combined cycle plants?
Rankine cycle
Carnot cycle
Otto cycle
Brayton cycle
What is the main purpose of the Heat Recovery Steam Generator (HRSG)?
To recover exhaust heat from the gas turbine to produce steam
To compress intake air
To increase combustion efficiency
To generate cooling water
Which unit is used to measure turbine output?
kW
N·m
kJ/kg
kg/s
What is the purpose of a deaerator?
To remove dissolved oxygen and gases from feedwater
To increase boiler pressure
To reduce condenser pressure
To increase feedwater pressure
Which component controls turbine load?
Superheater
Condenser
Deaerator
Governor system
What is the purpose of a deaerator?
To remove dissolved oxygen and gases from feedwater
To increase feedwater pressure
To increase boiler pressure
To reduce condenser pressure
What is the typical efficiency of modern hydro turbines?
20–30%
40–50%
85–95%
100%
What is the principal purpose of turbocharging a diesel engine in power plants?
To increase power density and efficiency
To lower lube oil consumption
To improve starting reliability
To reduce NOx
Which cycle represents the ideal operation of a spark ignition engine?
Rankine cycle
Diesel cycle
Otto cycle
Dual cycle
Which factor increases cycle efficiency by reducing exhaust wetness?
Steam reheating
Moisture separator
Poor circulation
Higher condenser pressure
Which system removes heat from the engine jackets?
Lubrication system
Starting system
Cooling water system
Fuel system
Which component regulates steam flow to turbine?
Governor valve
Fusible plug
Air preheater
Blowdown valve
What is the maximum turbine efficiency theoretically possible?
Limited by Carnot efficiency
100% (Carnot limit not applicable)
About 60%
Less than 50%
Which turbine operates efficiently under variable load with adjustable blades?
Kaplan turbine
Francis turbine
Turgo wheel
Pelton wheel
Which property of diesel fuel affects injection spray and atomization?
Viscosity
Cetane number
Density
Pour point
What is the typical life of hot-section components in heavy-duty gas turbines?
10,000–30,000 hours
50,000–100,000 hours
Infinite
2000–4000 hours
Which turbine uses adjustable runner blades?
Bulb turbine
Pelton wheel
Kaplan turbine
Francis turbine
What is the main effect of regeneration in a Rankine cycle?
Reduces pump work
Reduces fuel consumption
Lowers boiler pressure
Increases condenser pressure
Which efficiency is turbine shaft power / water power?
Hydraulic efficiency
Overall efficiency
Plant efficiency
Mechanical efficiency
Which control mode balances power between GT and ST in CCPP?
Automatic load control
Fixed pressure control
Sliding pressure control
Governor-only control
Which type of generator is used in hydro projects?
Synchronous generator
Induction generator
Stepper generator
Permanent magnet generator
Which part of boiler protects against overheating by fusible alloy?
Economizer
Fusible plug
Drum
Air preheater
What is the usual unit of alternator apparent power rating?
kW
MW
kVAR
kVA
Which parameter is used by load dispatch centers to forecast next-day generation?
Weather and historical demand data
Boiler water hardness
Generator pole count
Turbine blade length
Which efficiency is affected by leakage and friction in turbine casing?
Generator efficiency
Volumetric efficiency
Hydraulic efficiency
Mechanical efficiency
What is the primary function of dilution air in combustion chambers?
To increase flame speed
To improve fuel atomization
To reduce flame temperature
To enhance NOx formation
What is the significance of a daily load curve for plant scheduling?
It controls condenser pressure
It determines feedwater chemistry
It helps decide base and peak plant operation
It calculates furnace draft
Which turbine uses both fixed and moving nozzles?
Rateau turbine
Reaction turbine
Parsons turbine
Curtis turbine
Which factor defines plant capacity factor?
Flow / Gross head
Load factor / Peak demand
Reservoir volume / Net head
Actual energy generated / Maximum possible
Which efficiency is expressed as kWh per kg of fuel?
Heat rate
Boiler efficiency
Specific fuel consumption
Relative efficiency
Which property of fuel is most important for gas turbines?
Octane number
High calorific value and clean burning
High viscosity
Low octane number
What is the ideal cycle for a compression ignition engine?
Brayton cycle
Otto cycle
Stirling cycle
Diesel cycle
What is the function of a recuperator?
To recover heat for heating compressed air
To reduce turbine speed
To control exhaust gases
To increase turbine speed
Which factor reduces water hammer effects?
Low reservoir level
Poor turbine design
Surge tank and relief
High penstock velocity
What is the typical speed of a 50 Hz four-pole diesel generator?
1500 rpm
3000 rpm
1000 rpm
750 rpm
Which factor increases the efficiency of a Rankine cycle?
Superheating the steam
Increasing condenser pressure
Lowering inlet pressure
Reducing turbine inlet temperature
Which emission is primarily reduced by Exhaust Gas Recirculation (EGR)?
PM only
SO2
NOx
CO2
Which modification increases both power output and efficiency?
Afterburning
Combined cycle operation
Intercooling alone
Regeneration alone
What is the immediate action when low lube oil pressure alarm occurs during running?
Reduce load and shut down if pressure not restored
Ignore alarm
Increase load
Close cooling water
Which control mode holds generator voltage constant in island operation?
AVR constant voltage mode
VAR control with droop disabled
Droop reactive control only
PF control
Which factor determines the optimum reheat pressure in gas turbines?
Turbine efficiency
Material stress limits
Fuel viscosity
Equal work division between turbine stages
The adiabatic flame temperature increases when:
Combustion occurs at constant pressure
Combustion is stoichiometric
Fuel moisture increases
Excess air increases
Which law gives the distribution of radiation intensity with wavelength?
Wien's displacement law
Planck's law
Stefan–Boltzmann law
Kirchhoff's law
What is the function of a condenser hotwell?
To cool turbine blades
To collect condensate steam before pumps
To increase combustion temperature
To reduce fuel pressure
What is the purpose of a jacket water expansion tank?
To store lube oil
To trap exhaust condensate
To pressurize lube oil
To accommodate thermal expansion and remove air
Which efficiency is measured in kcal per kWh?
Specific fuel consumption
Boiler efficiency
Heat rate
Plant efficiency
Which factor is used to compare actual gas turbine cycle efficiency with the ideal cycle?
Polytropic efficiency
Mechanical efficiency
Isentropic efficiency
Overall cycle efficiency
Which factor sets generator short-circuit current level?
Fuel flow
Oil viscosity
Cooling water pH
Alternator reactances and excitation
What is the main purpose of the Heat Recovery Steam Generator (HRSG)?
To compress intake air
To generate cooling water
To increase combustion efficiency
To recover exhaust heat from the gas turbine to produce steam
Which factor affects cavitation index?
Generator losses
Net positive suction head (NPSH)
Fuel flow
Excitation
Which factor improves turbine reliability?
High exhaust moisture
Poor sealing
Scaling
Regular NDT and proper lubrication
Which efficiency is defined as power output divided by fuel energy input?
Gross efficiency
Heat rate
Isentropic efficiency
Thermal efficiency
Which cooling water property prevents scaling?
High chloride without control
High hardness
Proper alkalinity and anti-scalant treatment
No corrosion inhibitors
Which documentation is essential for safe operations?
Operating procedures, single-line diagrams, and LOTO plans
Only invoices
No procedures
Paint schedules
Which turbine is suitable for medium head?
Pelton wheel
Turgo wheel
Francis turbine
Kaplan turbine
Which cycle efficiency is reduced by irreversibilities?
Actual Rankine cycle
Ideal Rankine cycle
Otto cycle
Carnot cycle
Which fuel is most commonly used in large steam power plants?
Biomass
Natural gas
Diesel
Coal
What is the effect of regeneration on turbine exhaust temperature?
Constant
Increases
Doubles
Decreases
In a fuel oil burner, atomization improves with:
Proper pressure and nozzle design
Lower fuel pressure
Lower air pressure
Higher fuel viscosity
Which component separates steam and water in a boiler?
Economizer
Evaporator
Drum
Superheater
Which of the following has the highest calorific value per kilogram?
Hydrogen
Diesel oil
Bituminous coal
Methane gas
Which emission is reduced in combined cycle plants compared to coal plants?
NOx
SO2
All of the choices
CO2
Which parameter is directly used to calculate plant load factor?
Generator pole count
Turbine inlet pressure
Maximum demand and average demand
Boiler drum pressure
What is the purpose of a condenser vacuum in a steam cycle?
To stabilize combustion
To reduce turbine back pressure and increase efficiency
To increase turbine inlet pressure
To reduce fuel flow
Which cycle efficiency improves with reheat?
Diesel
Otto
Rankine
Brayton
Which parameter is monitored by drum level gauges in HRSG?
Turbine inlet pressure
Exhaust gas temperature
Condenser vacuum
Water level in steam drum
Which part on an IC engine absorbs heat from the combustion chamber to maintain temperature?
Flywheel
Cylinder head
Radiator
Cooling system
What is the role of the steam turbine in combined cycle plants?
To produce extra power from recovered heat
To increase fuel pressure
To compress air
To reduce exhaust emissions
Which efficiency is defined as (Gross Generation − Auxiliary Power) divided by Fuel Input?
Boiler efficiency
Gross efficiency
Heat rate
Net plant efficiency
Which factor defines hydro plant firm capacity?
Average load
Reservoir capacity
Maximum installed capacity
Guaranteed power output during minimum flow
Which thermal stress is most critical during frequent variable load cycling?
Tensile stress in chimney shell
Bending stress in condenser tubes
Axial stress in generator rotor
Hoop stress in turbine casing
What is the view factor used in radiation analysis?
Fraction of radiation leaving one surface that reaches another
Ratio of convection to conduction
Ratio of reflection to refraction
Ratio of absorptivity to emissivity
Which property of fuel affects flue gas loss?
Sulfur content only
Hydrogen content (latent heat of vaporization)
Density only
Ash content only
What is the typical capacity range of mini-hydro plants?
100 kW to 10 MW
Above 100 MW
10 to 50 MW
Less than 100 kW
Which parameter is measured to monitor turbine blade cooling effectiveness?
Inlet guide vane angle
Compressor discharge pressure
Turbine exhaust temperature profile
Lube oil temperature
What is the typical range of net plant efficiency for combined cycle power plants?
20–25%
50–60%
70–80%
35–45%
What is the function of the governor in a diesel generator set?
To control speed against load changes
To filter lubrication oil
To cool the engine
To regulate voltage
Which device is used for measuring turbine speed?
Piezometer
Pressure gauge
Tachometer
Manometer
What is the purpose of a barr-over (turning) gear?
To cool turbocharger
To speed up engine
To manually rotate engine for maintenance
To charge batteries
Which factor affects penstock design?
Pressure head, flow rate, and water hammer
Generator voltage
Excitation system
Fuel type
Which auxiliary system protects turbine in fire hazard?
Lube oil pump
Cooling fan
Turning gear
Fire detection and CO2 flooding system
Which system supplies ignition energy in gas turbines?
Magnetic pickup
Static excitation system
Spark plug or torch igniter system
Fuel injection only
Which efficiency compares electrical output to fuel energy input?
Volumetric efficiency
Mechanical efficiency
Overall plant efficiency
Mechanical efficiency
Which emission is largely influenced by fuel sulfur content?
SO2
CO
HC
NOx
What is the usual frequency of grid-synchronized diesel plants in many countries?
50 Hz or 60 Hz
25 Hz
75 Hz
90 Hz
Which method reduces condenser cooling water requirement?
Spray pond
Double flow condenser
Air-cooled condenser
Direct contact condenser
Which phenomenon causes vibration and pitting on turbine blades?
Water hammer
Head loss
Cavitation
Draft tube flow
Which factor increases work ratio in gas turbines?
High turbine inlet temperature
Low fuel calorific value
High compressor work
High exhaust pressure
What is the function of a feedwater pump?
To condense steam
To increase boiler pressure by pumping water into boiler
To superheat steam
To remove dissolved gases
Which factor improves Rankine cycle mean temperature of heat addition?
Low boiler pressure
Intercooling
Higher condenser pressure
Superheating
Which boiler mountings ensure safe working?
Superheater and reheater
Chimney and draft fan
Safety valve, fusible plug, water level indicator
Economizer and air preheater
Spontaneous combustion of coal is promoted by:
High volatile matter and poor ventilation
Presence of nitrogen
Low volatile matter
Low moisture
Ash fusion temperature is important to avoid:
Corrosion of burning
Formation of clinker and slagging
Low flame temperature
Excess NOx
