elements Flashcards
What is a type of reaction turbine usually with typical spiral casing where water enters the runner radially?
Francis Turbine
The Francis turbine is the most widely used type of hydraulic turbine for modern power generation purposes.
What is the name of the expanding tube connecting the outlet passage of a turbine with the tail water?
Draft Tube
What is a hydroelectric plant where excess water is pumped to an elevated space during off-peak periods?
Pumped Storage Plant
What is the channel that conducts water away from the turbine called?
Tailrace
What is the grid or screen composed of parallel bars that prevents floating debris from entering the penstock?
Trash Rack
What term refers to water in the reservoir?
Headwater
What is a propeller-type reaction turbine with adjustable guide vanes and runner blades?
Kaplan Turbine
What type of power utilizes the difference in elevation between high and low tide to produce energy?
Tidal Power
Which power plant’s output depends on the water flow in the river?
Run-of-River Plant
What is the intake pipe to a hydraulic turbine from a dam called?
Penstock
What kind of fluid flow occurs when the fluid travels parallel to adjacent layers?
Laminar flow
What conducts the water around the turbine?
Spiral casing
What are the movable vertical vanes that control the flow of water to the runner?
Wicket gate
What is the speed of a hypothetical model turbine that develops 1 hp at a head of 1 ft?
Specific speed
What is the difference in elevation between the headwater and the tailwater called?
Net head
What is the ratio of the effective head to the gross head?
Hydraulic efficiency
What is the ratio of the head utilized to the effective head?
Volumetric efficiency
Heads between 70 and 800 ft generally indicate which type of turbine?
Reaction turbine
Heads below about 70 ft call for which type of turbine?
Propeller turbine
What part of a hydraulic turbine helps reduce head loss at submerged discharge?
Draft tube
What tank at the transition from low-pressure headrace or tunnel protects against pressure changes?
Surge tank
What is the rotating part of the turbine where water imparts energy?
Runner
What is the formation and collapse of vapor bubbles in a liquid called?
Cavitation
What property of lubricating oil measures its thickness?
Viscosity
Fill in the blank: The velocity head of water can be calculated using the formula _______.
V^2/2g
The buoyant force on a floating object is equal to what?
Weight of displaced liquid
What is the primary purpose of a turbine in a fluid loop?
Add energy to the flow
What connects the turbine outlet to the tailwater?
Draft tube
What provides a means of releasing flow water that exceeds the design capacity of the dam?
Spillway
What is the power required to deliver a given quantity of fluid against a head with no losses called?
Hydraulic power
What is the velocity effect in fluid flow?
Velocity is zero at the wall and maximum at the center
What is a type of water turbine where a jet of water falls on blades or buckets?
Pelton wheel turbine
What is a vent or hole in the earth’s surface from which steam or hot gases issue called?
Fumarole
What is the typical depth of a geothermal production well in meters?
1500
What type of energy is transformed by a wind energy system into mechanical or electrical energy?
Kinetic Energy
What is the rhythmic rise and fall of the ocean waters called?
Tide
The power available in the wind is proportional to what of its speed?
Cube
What is the maximum tidal range called?
Spring tide
Natural gas is considered _____ when it is almost pure methane.
Dry
What type of reactor has water heated by nuclear fuel that boils to steam directly in the reactor vessel?
Boiling Water Reactor
What is the air pollution control device that collects fly ash in flue gas?
Electrostatic Precipitator
What component of a nuclear reactor slows down fast neutrons born during fission?
Moderator
What boron-coated steel rods are used to regulate the fission chain reaction?
Control Rods
What cycle describes the combination of a gas turbine generator with a steam turbine generator?
Brayton Cycle
Natural gas comprises mainly of _____
Methane
What is the coal ash that exits a combustion chamber in flue gas called?
Fly Ash
What is known as brown coal with a calorific value of less than 8,300 Btu/lb?
Lignite
What means using the same energy source for more than one purpose?
Cogeneration
What is the minimum amount of air required for complete combustion of fuel called?
Stoichiometric Air
What device measures the calorific value of a unit mass of fuel?
Calorimeter
When water in combustion products is in vapor form, the heating value is known as?
Lower heating value (LHV)
The percent excess air is calculated using the difference between the actual and theoretical air divided by what?
Theoretically air supplied
During a combustion process, the components existing before the reaction are called?
Reactants
What is the solidified mass of fused ash called?
Clinker
Why were older types of economizers constructed of cast iron?
Resists corrosion better than mild steel
What is an accessory installed on modern boilers to preheat air for combustion?
Air preheater
What components are included in the proximate analysis of solid fuel?
Fixed carbon, volatile matter, ash and moisture
Which element of fuel is not combustible?
Oxygen
What is a device used to record cylinder pressure and piston travel in an engine?
Engine Indicator
What diagram is used by engineers to detect issues like leaky piston packing?
Indicator diagram
What is the effective weight of the brake arm when the brake band is loose called?
Tare Weight
What is the ratio of heat converted to useful power to the heat supplied called?
Thermal efficiency
What is the ratio of the actual power of the engine to its ideal power called?
Engine efficiency
What is the power output of the generator called?
Net Tension
What is the term for the amount of fuel needed to perform a unit of power?
Specific fuel consumption
What is the ratio of heat converted to useful power to the heat supplied?
Thermal efficiency
What is the ratio of the actual power of the engine to its ideal power?
Generator efficiency
What is the ratio of the cylinder volumes after and before the combustion process called?
Compression ratio
What is the position of the piston when it forms the smallest volume in the cylinder?
Top Dead Center Position
What is the position of the piston when it forms the largest volume in the cylinder?
Bottom Dead Center Position
What type of engine has four events take place in one revolution of a crankshaft?
4-stroke cycle engine
What is the model cycle for spark ignition engines?
Otto cycle
Diesel engine fuel is rated in terms of what?
Cetane number
The distance that the piston can travel in one direction is known as the _______.
Stroke
What is the minimum volume formed in the cylinder when the piston is at the top dead center?
Clearance volume
What is the fictitious pressure that would produce the same amount of net work as that produced during the actual cycle?
Mean effective pressure
What is the ratio of constant pressure specific heat to the constant volume specific heat?
Specific heat ratio
What is the ideal cycle for compression-ignition reciprocating engines?
Diesel cycle
What is the power developed in the engine cylinder as obtained from the pressure in the cylinder?
Indicated power
What is the pressure and torque spent in overcoming friction of reciprocating and revolving parts of the engine?
Friction power
What is the instrument for determining brake power called?
Dynamometer
What is the indicator used to determine the anti-knock characteristics of gasoline?
Octane Number
What component draws fuel from the tank through the primary fuel filter?
Fuel transfer pump
What component acts as a balancer and provides momentum during dead stroke in a cycle?
Flywheel
What are steel tubes with a seat at both ends that bridge the motion from camshaft to rocker arm called?
Push rod
What is the passage of coolant from the engine block to the cylinder head called?
Water jacket
What is used to cool incoming air so that the volume of air available is increased?
After cooler
The difference between the maximum and minimum volume is known as _______.
Displacement Volume
What are used to seal the gases within the cylinder and to keep oil out?
Piston Rings
In the Otto cycle, the process where heat is added is at _______.
constant volume
In the Diesel cycle, the process where heat is added is at _______.
constant pressure
What is used to reduce friction of bearings and sliding surfaces in machines?
Lubricant
In a heat engine, the ratio of brake power to the indicated power is called _______.
thermal efficiency
What is the ratio of the average load to the peak load over a designated period of time?
Load Factor
What is the ratio of the sum of individual maximum demands of the system to the overall maximum demand called?
Diversity Factor
What is the sum of the continuous ratings of all the equipment and outlets on the customer’s circuit?
Connected load
What is the ratio of the duration of the actual service of a machine to the total duration called?
Utilization factor
What is the ratio of the brake mean effective pressure to the indicated mean effective pressure?
Brake engine efficiency
What is the ratio of the combined engine efficiency to the brake engine efficiency?
Combined thermal efficiency
The difference between the power plant installed capacity and the peak load is called _______.
reserve over peak
What is a series of processes during which the initial and final state points are the same called?
Cycle
The compressibility factor of an ideal gas is equal to _______.
1.00
What does the relation pV=C represent?
Isothermal process
In the relation pVn=C, if n=0, the process is called _______.
Isometric process
In a Carnot cycle, heat rejection occurs during the _______.
Isothermal compression
What type of system has mass inflow and outflow that are not equal?
Unsteady state, unsteady flow system
What form of energy is a function of temperature for perfect gases?
Internal energy
What is defined as the force of gravity per unit volume of a substance?
Specific weight
What is a thermodynamic system whose mass does not cross its boundaries called?
Closed system
Which law states that the acceleration of a body is directly proportional to the resultant force?
Newton’s Second Law of Motion
What is a substance that receives, transports and transfers energy called?
Working substance
What law of thermodynamics states that energy can neither be created nor destroyed?
First Law of Thermodynamics
What states that the total pressure of a gaseous mixture is equal to the sum of the partial pressures?
Dalton’s Law
What is the point at which the saturated liquid and saturated vapor states are identical?
Critical point
The point at which heat transfer stops is known as _______.
Thermodynamic equilibrium
What instrument is used for determining the specific gravity of a solution?
Hydrometer
What temperature refers to when all molecular motion ceases?
0 oK
What does the area under the curve on a pressure-volume diagram represent?
Net Work
A boiler steam pressure gauge should have a range of at least _______ times the maximum allowable working pressure.
1.25
What is a valve designed to allow a fluid to pass through in one direction only called?
Check valve
What is the enthalpy change of an ideal gas compressed isothermally?
Zero
What is constant in an adiabatic throttling process?
Enthalpy
What is the ideal cycle for a gas turbine plant?
Brayton cycle
What is the most thermally efficient cycle consisting of two isentropic and two isothermal processes?
Carnot cycle
How can the average temperature during heat rejection process of a Rankine cycle be decreased?
reduce turbine exit pressure
What is commonly done to a vapor power cycle when the turbine has excessive moisture?
reheating
What is the form of energy transferred between two systems by virtue of temperature difference?
Heat
What type of thermodynamic process has no heat transfer?
Adiabatic Process
What is an energy interaction not caused by a temperature difference called?
Work
What is the process where solid directly changes to vapor without passing through liquid state?
Sublimation
A rigid container heated by the sun has a work output that is _______.
equal to zero
The net work output of a heat engine is always _______.
less than the amount of heat input
What is the sum of all the energies of all the molecules in a system called?
Internal Energy
What is a liquid whose temperature is below the saturation temperature corresponding to its pressure?
Subcooled liquid
A device that violates the first law of thermodynamics is called a _______.
Perpetual motion machine of the first kind
The efficiencies of all reversible heat engines operating between the same two reservoirs _______.
are the same
A process with no heat transfer is known as _______.
adiabatic process
The relative density of a substance is the ratio of its density to the density of _______.
water
What type of heat exchanger allows fluids to flow at right angles to each other?
Cross flow
The principle that total energy in any one energy system remains constant is called the principle of _______.
Conservation of Energy
A process for which the inlet and outlet enthalpies are the same is called _______.
Isenthalpic
The sum of energies of all the molecules in a system appears in several complex forms, what is it called?
Internal Energy
What is a system that is completely impervious to its surrounding called?
Isolated system
What device is used to measure small and moderate pressure difference?
Manometer
What is a vapor having a temperature higher than the saturation temperature called?
Superheated vapor
What is the energy or stored capacity for performing work possessed by a moving body?
Kinetic energy
What thermodynamic process maintains constant temperature and has zero change in internal energy?
Isothermal process
What is the function of a pump or compressor?
increase the total energy content of the flow
This law states that all energy received as heat by a heat-engine cannot be converted into mechanical work.
Second Law of Thermodynamics
What is the thermodynamic process wherein temperature is constant and the change in internal energy is zero?
Isothermal process
In an isothermal process, the temperature remains constant, implying that the internal energy does not change.
What is the function of a pump or compressor?
Increase the total energy content of the flow
Pumps and compressors are used to increase the energy of a fluid flow.
Which law states that all energy received as heat by a heat-engine cannot be converted into mechanical work?
2nd Law of Thermodynamics
The 2nd Law highlights the limitations of energy conversion processes.
What is the intensity of pressure measured above absolute zero called?
Absolute pressure
Absolute pressure is the total pressure relative to a perfect vacuum.
What is the term for the ratio of the heat equivalent of the brake or useful horsepower developed by an engine to the heat during the same time?
Brake thermal efficiency
It measures how effectively an engine converts heat into work.
Fill in the blank: Flow work is equal to pressure times _______.
Specific volume
Flow work is an important concept in fluid mechanics and thermodynamics.
What type of energy is due to the position or elevation of the body?
Potential energy
Potential energy is energy stored due to an object’s position.
What is another term for a constant volume process?
Isochoric process
The isochoric process maintains a constant volume while pressure and temperature may vary.
What is the efficiency of the Carnot cycle dependent upon?
Temperature
The Carnot cycle is a theoretical model that establishes the maximum possible efficiency of a heat engine.
What is the heat required in a constant-pressure process to completely vaporize a unit mass of liquid at a given temperature called?
Enthalpy of vaporization
This term is crucial in thermodynamics for phase change calculations.
Which device is commonly used for measuring temperature differences or high temperatures?
Thermocouple
Thermocouples are widely used due to their accuracy and wide temperature range.
What is the rate of doing work per unit of time called?
Power
Power is a measure of how quickly work is done or energy is transferred.
In an ideal Rankine cycle, what happens to the thermal efficiency if the steam is superheated to a higher temperature?
The cycle thermal efficiency will increase
Superheating improves the efficiency of heat engines by increasing the temperature of the working fluid.
What is a vapor having a temperature higher than the saturation temperature corresponding to the existing pressure called?
Superheated Vapor
Superheated vapor is essential in many thermodynamic applications.
What is the work done in pushing a fluid across a boundary called?
Flow Work
Flow work is a key concept in fluid dynamics and thermodynamics.
What type of liquid has a temperature lower than the saturation temperature corresponding to the existing pressure?
Subcooled liquid
Subcooled liquids are used in various thermal systems to enhance efficiency.
In a water-tube boiler, where does the water pass through?
Inside the tubes
Water-tube boilers are designed for high-pressure steam generation.
What is the temperature to which the air becomes saturated at constant pressure called?
Wet-bulb temperature
Wet-bulb temperature is important in psychrometry and HVAC applications.
What is the ratio of the mass of water vapor in a certain volume of moist air to the mass of water vapor in the same volume of saturated air at the same temperature called?
Specific humidity
Specific humidity is a crucial measure in meteorology and HVAC.
What is the term for the simultaneous control of temperature, humidity, air movement, and quantity of air in space?
Air-conditioning
Air-conditioning systems are essential for maintaining comfort in indoor environments.
Fill in the blank: The temperature at which the water vapor content of moist air begins to condense when air is cooled at constant pressure is called _______.
Dew Point Temperature
Dew Point Temperature is critical for understanding humidity and condensation processes.
What is the index of performance of a refrigeration system which is a dimensionless quantity called?
Coefficient of Performance
Coefficient of Performance measures the efficiency of refrigeration systems.
What happens to the pressure of a confined gas at constant temperature if it is tripled?
The volume will be reduced to one-third of its original value
This is a direct application of Boyle’s Law.
What is the pressure of the refrigerant between the expansion valve and the intake of the compressor in a multi-pressure refrigeration system?
Low-side pressure
Understanding pressure points in refrigeration systems is crucial for effective system design.
What does the term ‘sensible heating or cooling’ refer to?
The rate of heat transfer attributable only to a change in dry-bulb temperature
This concept is fundamental in HVAC design and analysis.
What is the power output in kW if the energy rate is 49.232 kJ/s?
49.232 kW
What is the horsepower equivalent of 49.232 kW?
65.99 hp
Calculate the pressure at the bottom of a water tank that is 4 ft high.
1.733 psi
Convert 750 mm Hg to kN/m2.
99.99 kPa
What is the weight of water in a tank measuring 18 ft wide, 24 ft long, and 4 ft deep?
49 tons
What is the volume flow rate of oil through 16 tubes with a velocity of 2 m/s and an internal diameter of 30 mm?
22.62 liters/s
Convert a temperature of 620 deg R to degrees Celsius.
71.11
What is the unknown volume of gas if it expands to a 10 m3 container at 500 mm Hg?
6.58 m3
What is the density of an iron block weighing 5 Newton with a volume of 200 cm3?
2549.30 kg/m3
What is the specific volume of air at a pressure of 22.22 psia and temperature of 800 deg R?
13.33 ft3/lbm
What is the specific weight of mercury with a specific gravity of 13.55?
132.88 kN/m3
What is the equivalent weight of a mass of 10 kg at an acceleration of gravity of 9.77 m/sec2?
97.7 N
Calculate the minimum volume tank necessary to transport 100 liters of gas at 80°F and 8 atm.
13.72 liters
What is the specific volume of a mixture of 100 g of water and 150 g of alcohol?
1.16 x 10-3 cu.m/kg
How much does 30 lbm weigh on the moon with gmoon = 5.47 ft/s2?
5.1 lbf
What is the change in potential energy for a 10 kg block raised vertically 3 meters?
294.2 J
Convert 100 gallons of liquid to cubic meters.
0.3785 m3
What is the horsepower output of a steam turbine receiving 1014 lbm/hr of steam with work done of 251 Btu/lbm?
100 Hp
What is the resulting pressure when one pound of air at 15 psia and 200°F is heated to 800°F?
28.64 psia
How many grams of CO2 are contained in a bicycle tire with a volume of 600 cm3 and pressure of 551.43 kPa?
5.98 g
What is the height of a vertical column of water with an absolute pressure of 15.5 psia?
22.15 in.
What is the work done in pushing a fluid across a boundary called?
Flow Energy
What is the energy balance equation for a steady flow process?
Energy (in) = Energy (out)
Convert a water temperature rise of 18°F to degrees Celsius.
10 oC
What is the hydrostatic pressure at the bottom of an oil storage tank with specific gravity 0.88 and depth 20 meters?
1.76 kg/cm2
What height will a vertical column of water be supported by standard atmospheric pressure?
33.92 ft
What is the equivalent specific weight of a liquid with a specific weight of 60 lb/ft3 in kN/m3?
9.42 kN/m3
What pressure does a 150 lbf cylinder exert on the floor with a cross-sectional area of 40 square inches?
0.2586 bar
What law states that energy is neither created nor destroyed but can change forms?
First Law of Thermodynamics
What is the absolute pressure exerted on a submarine cruising 300 ft below the sea surface with specific gravity of seawater 1.03?
148.60 psia
What is the mass flow rate through a nozzle with an inlet area of 80 cm2, air density of 2.21 kg/m3, and velocity of 30 m/s?
0.5304 kg/s
Calculate the work required to accelerate an 800-kg car from rest to 100 km/h.
308.64 kJ
Heat is defined as a form of energy that is transferred due to a _______.
Temperature difference
Find the speed of a 3220-lbm body after it falls 778 ft from rest.
223.75 ft/s
What is the flow rate through a pipe 4 inches in diameter carrying water at a velocity of 11 ft/sec?
430.84 gpm
If the specific weight of a liquid is 58.5 lbf per cubic foot, what is its specific volume in cm3/g?
1.0675 cm3/g
What is the resulting pressure when one pound of air at 0.3 psig and 200°F is heated at constant volume to 800°F?
28.64 psia
Axial fans are best suitable for which application?
Large flow, low head
What is the equation used to relate pressures and temperatures in a fluid system?
P1/T1 = P2/T2
This equation is used for calculating pressures and temperatures in relation to each other in thermodynamic processes.
What is the most suitable application for axial fans?
Large flow, low head
Axial fans are designed to move large volumes of air at low pressure.
Which type of axial fan is most efficient?
Vane axial
Vane axial fans are equipped with blades that can be adjusted for maximum efficiency.
What device maintains constant rotative speed in a hydraulic turbine under varying load?
Governor
A governor adjusts the gate openings to maintain speed.
What is the purpose of a penstock in a hydraulic system?
To carry water from reservoir intake to a reaction turbine
A penstock is a crucial component in hydroelectric systems.
How does the efficiency of forward curved centrifugal fans compare to backward curved fans?
Lower
Forward curved fans typically have lower efficiency than backward curved fans.
What does BEP stand for in pump operation?
Best Efficiency Point
Operating near BEP ensures optimal performance and longevity of the pump.
What is used to prevent shock or water hammering in a penstock?
Surge Tank
Surge tanks act as buffers to absorb pressure changes.
Which fan type is more suitable for high pressure applications?
Backward curved centrifugal fan
This type of fan can handle higher pressures effectively.
What characterizes a Francis type centrifugal pump impeller?
Wide passages for water and an outside to eye diameter ratio of about 1.5
Francis pumps are versatile and widely used in various applications.
What is the purpose of a mechanical seal in a centrifugal pump?
To maintain an air tight seal as the impeller shaft passes
Mechanical seals prevent leakage and maintain pressure.
What shape do pump performance characteristic curves for two identical pumps in series take?
B
The curves demonstrate flow and head characteristics when pumps are combined.
What component converts velocity energy to pressure head in a centrifugal pump?
Diffuser
The diffuser plays a crucial role in converting kinetic energy into pressure.
If two identical centrifugal pumps are installed in parallel, what happens to the flow rate?
It is doubled
Parallel installation increases the total flow capacity.
What type of valve is used to prevent backflow in a fluid pipe?
Check Valve
Check valves ensure fluid flows in one direction only.
What type of pump is characterized by vortex and periphery designs?
Turbine (Regenerative) Pumps
These pumps are designed for specific applications requiring high efficiency.
Which type of pump does not belong to the group: Screw Rotary Pump, Diaphragm Pump, Direct Acting Steam Pump, Centrifugal Pump?
Centrifugal Pump
The other types are positive displacement pumps, while centrifugal pumps work differently.
What material is preferred for impellers handling average waters?
Stainless Steel
Stainless steel is resistant to rust and easy to machine.
What is a single-stage or multistage centrifugal pump with a pumping element suspended from discharge piping called?
Vertical Turbine Pump
These pumps are often used in deep well applications.
What type of pumps are intended for handling thick pulps and sewage sludge?
Lobe pumps
These pumps can handle viscous and solid-laden fluids.
What is the principal pumping member of a rotary pump?
Rotor
The rotor is essential for the pump’s mechanical action.
What is the relationship of the capacity of a centrifugal pump, Q, to impeller diameter, D?
Q is directly proportional to the square of D
This relationship shows how impeller size affects flow capacity.
What is the relationship of horsepower, P, to impeller speed, N, in a centrifugal pump?
P is directly proportional to the cube of N
This indicates how power requirements increase with speed.
Which hydraulic turbine is suitable for low head applications?
Kaplan turbine
Kaplan turbines are designed for low head and high flow scenarios.
If two identical centrifugal pumps are installed in series, what happens to the system flow rate?
Remains the same
Series installation increases head but not flow rate.
What phenomenon occurs when pump inlet suction pressure falls below the vapor pressure of the liquid?
Cavitation
Cavitation can lead to damage and inefficiency in pumps.
What is the process called when a centrifugal pump fills its suction line to remove air?
Priming
Priming is necessary for the pump to operate correctly.
Which type of pump does not belong to the group: gear pump, vane pump, screw pump, diaphragm pump?
Diaphragm pump
Diaphragm pumps are positive displacement pumps, while the others are typically rotary.
