ME 252 Review: Final Exam
Open book, notes, HW
Coverage: Vapor Power Cycles, Gas Power Cycles, Refrigeration, Psychrometrics, Combustion, Fuel Cells,
Renewable Energy Systems: Photovoltaic & Wind
Terminology:
Rankine cycle
Reheat
Open feedwater heater
Trap
Back work ratio
Regeneration
Closed feedwater heater
Binary vapor cycle
Superheat
Isentropic efficiency
Extraction pressure & mass fraction
Cogeneration
Spark-ignition
Clearance volume
Cold-air standard analysis
Diesel cycle
Autoignition
Volumetric efficiency
Regeneration
Stirling cycle
Turbofan engine
Combined cycle
Compression-ignition
Mean effective pressure
Otto cycle
Cut-off ratio
Turbocharging
Brayton cycle
Intercooling
Turbojet engine
Centrifugal compressor
Displacement volume
Air-standard analysis
Compression ratio
Dual cycle
Brake horsepower
Pressure ratio
Reheat
Turboprop engine
Positive-displacement compressor
Vapor-compression cycle
Coefficient of performance
Expansion valve
Heat pump
Vortex tube
Refrigeration capacity
Condenser
Cascade & multistage V-C
Gas (Brayton) refrigeration
CFC, HCFC, HFC
Ton of refrigeration
Evaporator
Absorption refrigeration
Thermoelectric refrigeration
Dalton’s law
Relative humidity
Dry-bulb temperature
Adiabatic saturation
Simple heating/cooling
Evaporative cooling
Natural-draft
Partial pressure
Mixture enthalpy
Wet-bulb temperature
Makeup water
Humidification
Adiabatic mixing
Forced-draft
Humidity ratio, or specific humidity
Dew-point temperature
Sling psychrometer
Psychrometric chart
Dehumidification
Cooling tower
Tower effectiveness
Fuel/Oxidizer
Complete combustion
Stoichiometric combustion
Equivalence ratio
Higher heating value (HHV)
Hydrocarbon
Air-fuel ratio
Excess air
Enthalpy of formation
Adiabatic flame temperature
Reactant/Product
“Three T’s” of combustion
Theoretical air
Lower heating value (LHV)
Fuel cell
Oxidation-reduction
Gibbs free energy
Reforming
Anode
Electrolyte
Conversion efficiency
Cathode
Catalyst
Proton Exchange Membrane (PEM)
Solar irradiance
Charge controller
HAWT vs. VAWT
Stall control
Photovoltaic
Inverter
Capacity factor
Pitch control
Cell/module/panel/array
Maximum power point
Upwind/Downwind rotor
Yaw error
You should understand:
 the various ways to increase the thermal efficiency of the Rankine cycle
 why reheating is used in vapor power cycles
 the differences between open and closed feedwater heaters
 the desirable characteristics of working fluids for vapor power cycles
 differences between Otto, Diesel, and Brayton cycles
 the function of turbocharging
 how intercooling, reheat, and regeneration affect Brayton cycle performance
 the differences between turbojet, turboprop, and turbofan aircraft engines
 differences between ideal and actual vapor-compression cycles
 refrigerant properties and the problem of ozone depletion
 modifications to vapor-compression cycles (cascading, multistaging)
 alternative refrigeration schemes (absorption, thermoelectric, Brayton, vortex tube)
 how a cooling tower operates
 how a fuel cell operates
 the fuel cell components and their desirable characteristics
 the H2-O2 fuel cell reaction
 the effect of temperature on fuel cell performance
 the different types of fuel cells, their uses, and relative advantages
 what reforming is
 the primary components of a stand-alone PV system
 the primary components of a wind turbine system
You should know how to:
 analyze Rankine cycles with or without reheating and feedwater heating
 analyze Otto, Diesel, and Brayton gas power cycles using air-standard assumptions
 analyze turbocharged Otto and Diesel cycles
 analyze regeneration, intercooling, and reheat in Brayton cycles
 analyze ideal and actual vapor-compression refrigerators and heat pumps
 analyze gas (Brayton) refrigeration cycles
 sketch Rankine, Otto, Diesel, Brayton, and refrigeration cycles using T-s, P-v, and T-v coordinates
 analyze ideal and actual vapor-compression refrigerators and heat pumps
 select appropriate refrigerants and operating pressures/temperatures
 sketch vapor-compression refrigeration cycles using T-s coordinates
 determine humidity ratio, relative humidity, dew-point temperature, dry-bulb temperature, wet-bulb
temperature, mixture enthalpy, and mixture specific volume from the psychrometric chart or exact
equations
 determine vapor (partial) pressure from relative humidity
 perform mass and energy balances of moist air undergoing simple heating or cooling, humidification,
dehumidification, evaporative cooling
 draw moist air processes on a psychrometric chart
 analyze cooling towers
 balance combustion reaction equations involving hydrocarbon fuels
 determine % excess air, % theoretical air, and air-fuel ratio
 determine dew-point temperature of water vapor in products
 perform an energy balance of a combustion chamber and determine the heat transfer or required fuel mass
flow rate
 determine LHV and HHV of hydrocarbon fuels
 determine adiabatic flame temperature (even though this is an unreasonable computation for an exam)