Flashcards
ThermoFluid Systems Design
Flashcards do conjunto (87)
- 1CompressorsFans that generate pressure differences in excess of 30 IWG
- 2FanA fluid machine that is used to move and induce flow of a gas (also referred to as a blower)
- 3Major Head LossPressure loss due to viscous effects in fully developed flow in constant area pipes or ducts
- 4Minor Head LossPressure loss due to entrances, fittings, valves, and area changes
- 5AnalysisApplication of principles to a well defined problem
- 6DesignApplications of principles to an undefined, open problem; not 1 correct answer
- 7What are the general steps of Design?1. Develop preliminary specifications/constraints
2. Detailed specs, evaluate concepts, perform feasibility study
3. Detailed design and economic analysis
4. Present design with results of analysis
5. Fabricate and test prototype
6. Fabricate and manufacture
7. Market product - 8Reynold's NumberCharacterizes the flow regime (laminar vs. turbulent); inertial force over viscous force
- 9Friction FactorUsed to predict head loss based on the friction of the pipe (refer to Moody's Diagram)
- 10Moody's DiagramA family of curves that relate the friction factor to the relative roughness of the pipe
- 11Hydraulic DiameterUsed when handling flow in noncircular pipes/ducts
- 12Typical Performance CurveCurves of the external static pressure vs the volume flow rate of a fan operating at various speeds
- 13Shut-off PointNo flow occurs when the external static pressure is maximum
- 14Free-Delivery PointExternal static pressure is a minimum so volume flow rate is a maximum
- 15Fan LawsRelationships among the various performance parameters that can determine new values as a result of new changes (Ex. flow rate, fan speed, gas density)
- 16PumpMoves liquid, adds energy to keep the fluid moving, overcomes head loss, and/or build pressure to overcome elevation
- 17Pump CapacityVolume flow rate of fluid through the pump
- 18Pump Net HeadIncreases fluid energy; absolute pressure at the head of the pump
- 19Water HorsepowerPower delivered directly to the fluid by the pump
- 20Brake HorsepowerExternal power supplied to the pump by a mechanical shaft or motor
- 21Pump EfficiencyRatio of useful power to supplied power
- 22Pump Performance/ System CurvesCurves of height, efficiency, and bhp as functions of volume flow rate
- 23CavitationThe formation of bubbles or cavities in liquid, developed in areas of relatively low pressure (negative effects on the pump)
- 24NPSH(R)Net Pump Suction Head (Required); used to ensure inlet pressure is greater than vapor pressure to avoid cavitation
- 25Open-loop PipingSome part of the circuit is open to the atmosphere
- 26Closed-loop PipingNo points are open to the ambient/surroundings
- 27Heat ExchangerDevices that facilitate energy transfer between two fluids at different temperatures without the fluids mixing
- 28Double Pipe Heat ExchangerOne fluid flows through a pipe and the other fluid flows through the space surrounding said pipe
- 29Overall Heat TransferThe amount of heat moved across the surfaces in a heat exchanger
- 30Thermal Resistance NetworkA series of resistances to the flow of heat through boundaries within the system
- 31Nusselt NumberNondimensionalized heat transfer coefficient
- 32Dittus-Boelter CorrectionUsed to determine the Nusselt number for fully developed turbulent flow in smooth tubes
- 33Log-Mean Temperature Difference MethodUsed to determine heat transfer surface area, the outlet temperatures of the fluid, or the heat transfer rate
- 34Effectiveness of Heat ExchangerEfficiency of exchanging energy between the two fluids
- 35Number of Transfer UnitsNumber of items transferring energy within the system
- 36Number Transfer Unit Efficiency Method (e-NTU)Method for heat transfer design and performance analysis
- 37Check ValvePrevents Backflow of water into the boiler when the pump is not energized
- 38Relief ValveProtects the boiler from excessive pressure buildup and possible rupture
- 39Hydronic Heating SystmsHot water, multicomponent systems used to heat water; also can be used to heat infrastructures
- 40FeedwaterA line that supplies fresh plant or building water to a boiler
- 41I=B=RMost conservative rating system for larger capacity boilers and water heaters
- 42AFUEAnnual Fuel Utilization Efficiency of the boiler
- 43Orifice Plate/ Balancing ValveUsed to improve (flow) balance within the system
- 44Gas CycleWorking fluid remains as a gas throughout the entire cycle
- 45Brayton CycleType of gas cycle; gas-turbine system based on air or combustion gas as the working fluid
- 46Vapor CycleThe working fluid is a gas in one part of the cycle and a liquid in another
- 47Rankin CycleType of vapor cycle; steam turbine system with pressurized, superheated steam entering and liquid water leaving
- 48Carnot CycleAn ideal reversible cycle that can operate between two constant temperature reservoirs
- 49Contact/Open Feedwater HeaterDirect mixing of steam with liquid water
- 50Surface/Closed Feedwater HeaterNo direct mixing of steam and liquid water
- 51ReheaterReheats partially expanded steam; increases performance and life of the turbine
- 52HHVHigher heating value
- 53LHVLower heating value
- 54DCADrain Cooler Approach; Method to find temperature of inlet water; drain cooler collects liquid condensate to recover energy
- 55TTDTerminal Termperature Difference; for a drain cooler; method to find the exiting pipe water temperature
- 56Steam TurbineComponent that generates the power that is converted to electrical power by the generator
- 57Impulse TurbineSteam expands in stationary nozzles
- 58Reaction TurbineSteam expands in both stationary nozzles and across moving blades
- 59Expansion Line End PointThe steam conditions at the exit of the last stage of the LP Turbine
- 60Used Energy End PointSteam conditions at the condenser inlet
- 61Mollier DiagramPlots straight expansion lines between h in and out to find enthalpies of the steam bled from the turbine
- 62NHRRatio of the total heat input to the net generator output
- 63AvailabilityReversible work produced when the cycle working fluid changes to the state that is in thermal and mechanical equilibrium with the environment
- 64Gas TurbineAir or combustion gas mixture is the working fluid
- 65EconomizerThe section of the boiler in which compressed water is heated but not vaporized
- 66Water HammerA large pressure surge that shakes and breaks pipes
- 67Steam BlanketingOccurs when steam and liquid water are not mixed (causes erosion of the pipes)
- 68EvaporatorSection of the pipe that serves to reduce the exhaust gas temperature and bring the water to boiling point
- 69SuperheaterSteam is superheater for the steam turbine
- 70TurbineA machine for which power is continuously produced by a working fluid moving a wheel or motor
- 71Balance DamperControl dampers that balance the flow of air but are not intended for a positive shutoff or automatic control
- 72PVCPolyvinyl Chloride
- 73CPVCChlorinated Polyvinyl Chloride
- 74PEXCross-linked Polyethylene
- 75ABSAcrylonitrile Butadiene Styrene
- 76SurgeSudden powerful forward or upward movement
- 77IWGInches of water gauge
- 78Dip TubeLong plastic tubes that fit into the inlet of a water heater to direct incoming cold water to the bottom of the heater
- 79EntropyUnavailability of a system's thermal energy for conversion into mechanical work
- 80EnthalpyTotal heat content in a system; internal energy + pressure*volume
- 81First Law EfficiencyBased upon the First Law of Thermodynamics; based on the actual energy use and not taking into account things like excess energy
- 82Second Law EfficiencyBased on the Second Law of Thermodynamics; instead of energy, uses free energy within the system
- 83Saturation Temperature/PressurePoint at which a liquid reaches its boiling point to turn to vapor
- 84Steam Turbine Internal EfficiencyConversion of input energy into output work without dissipating energy
- 85Compressed LiquidIs a fluid under mechanical or thermodynamics conditions that force it to be a liquid
- 86Saturated LiquidA liquid whose temperature and pressure are such that any decrease in pressure without changes in temperature which causes it to boil
- 87Superheated LiquidLiquid water under pressure at temperatures between the usual boiling point and the critical temperature
Informações
- Descrição
- Series of terms and design specification for thermofluid systems design (4th Year Mechanical Engineering study notes)
- Criado por
- Kathryn D
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