PIPE 5 WEEK 7

    Master this deck with 150 terms through effective study methods.

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    Created by @kinito24

    What happens to the temperature of air after passing through a convergent-divergent nozzle?

    It decreases.

    What happens to the density of air after passing through a convergent-divergent nozzle?

    It decreases.

    What happens to the Mach number of air after passing through a convergent-divergent nozzle?

    It decreases.

    What remains unaffected by increasing the temperature source in a Carnot cycle?

    Heat rejected.

    What remains unaffected by decreasing the temperature sink in a Carnot cycle?

    Heat added.

    What increases when superheating the refrigerant in a vapor compression cycle with useful cooling?

    Heat rejected from condenser.

    What decreases when superheating the refrigerant in a vapor compression cycle with useful cooling?

    Compressor power.

    What decreases when superheating the refrigerant in a vapor compression cycle without useful cooling?

    COP.

    What increases when superheating the refrigerant in a vapor compression cycle without useful cooling?

    Compressor power.

    What remains unaffected by superheating the refrigerant in a vapor compression cycle without useful cooling?

    Compressor power.

    What increases when sub-cooling the refrigerant in a vapor compression cycle at condenser exit?

    Refrigerated effect.

    What decreases when sub-cooling the refrigerant in a vapor compression cycle at condenser exit?

    Mass flow rate.

    What increases by raising the vaporizing temperature in a vapor compression cycle?

    COP.

    What decreases by raising the vaporizing temperature in a vapor compression cycle?

    Temperature difference between evaporator and compressor.

    What increases by raising the condenser pressure in a vapor compression cycle?

    Moisture content after expansion.

    What increases if the pressure drop in the condenser increases in a vapor compression cycle?

    Heat rejected in the condenser.

    What decreases if the pressure drop in the condenser increases in a vapor compression cycle?

    Mass flow rate.

    What remains unaffected if the pressure drop in the condenser increases in a vapor compression cycle?

    Compressor power.

    What increases if the pressure drop in the evaporator increases in a vapor compression cycle?

    Heat rejected in the condenser.

    What decreases if the pressure drop in the evaporator increases in a vapor compression cycle?

    COP.

    What decreases by lowering the condenser pressure in a Rankine cycle?

    Heat rejected.

    What decreases by increasing the boiler pressure in a Rankine cycle?

    Heat rejected.

    What decreases when superheating steam to a higher temperature in a Rankine cycle?

    Moisture content at the turbine exhaust.

    What increases when superheating steam to a higher temperature in a Rankine cycle?

    Condenser pressure.

    What decreases when reheating steam before entering the second stage in a Rankine cycle?

    Moisture content after expansion.

    What increases when the Rankine cycle is modified with regeneration?

    Cycle efficiency.

    What defines intermediate load?

    Combination of base load and peaking load.

    What is the sum of maximum demand over simultaneous maximum demand?

    Diversity factor.

    What is the efficiency of regenerative feed heating cycle with infinite feedwater heaters?

    Carnot cycle.

    What type of turbine is used in desalination of seawater?

    Back pressure turbine.

    What law states that an electric voltage is induced in a conductor when it moves relative to a magnetic field?

    Faraday’s law.

    What device transfers heat directly to electrical energy using thermionic emissions?

    Thermionic generator.

    What does the loss in weight of coal at 105°C for 1 hour indicate?

    Moisture content.

    What is eliminated when heating coal at 950°C for 7 minutes?

    Volatile matter and moisture.

    What consists of hydrogen and certain hydrogen carbon compounds removed from coal by heating?

    Volatile matter.

    What is formed by burning coal in an uncovered crucible?

    Ash.

    What is the process used to produce coke from caking coal?

    Heating in absence of air.

    What is the grindability of standard coal?

    100.

    What is the major constituent of all natural gases?

    Methane.

    What are the two types of fans?

    Centrifugal and axial.

    What is the enthalpy of a substance at a specified state due to its chemical composition?

    Enthalpy of formation.

    What type of boiler is used for supercritical pressure operation?

    Once through-circulation boiler.

    What heats the economizer in a water tube boiler?

    Outgoing flue gas.

    What receives heat partly by convection and partly by radiation?

    Pendant superheater.

    What is the energy storage medium in regenerative superheaters?

    Matrix.

    What type of working fluid does the Stirling cycle use?

    Compressible fluids.

    What process adds heat during the Stirling process?

    Isothermal process.

    What is the Brayton cycle also known as?

    Joule cycle.

    What cycle is applied to propulsion of vehicles due to practical characteristics?

    Brayton cycle.

    What do heat exchangers typically involve?

    Energy interaction.

    What device converts heat to work?

    Heat engines.

    What is the objective of a heat pump?

    Maintain a heated space at high temperature.

    What device violates the second law of thermodynamics?

    Perpetual motion machine of second kind.

    What is a process called if no irreversibilities occur outside the system boundaries?

    Externally reversible.

    What energy interaction is not accompanied by entropy transfer?

    Work.

    What method uses a turbine driven by exhaust gases to provide power to a compressor?

    Turbocharging.

    What device has significant changes in kinetic energy?

    Nozzles and diffusers.

    What is the distance between TDC and BDC in an engine?

    Stroke of the engine.

    What causes self-ignition in a compression engine?

    Compressing the air-fuel mixture above its self ignition temperature.

    What does the thermal efficiency of an ideal Otto cycle depend on?

    Compression ratio and specific heat ratio.

    What happens to the thermal efficiency of an Otto cycle using monoatomic gas?

    It increases.

    What type of process occurs during combustion in a diesel engine?

    Constant pressure process.

    What happens to the efficiency of the diesel cycle if the cutoff ratio decreases?

    It increases.

    What process occurs during regeneration in the Ericson cycle?

    Constant pressure.

    What happens during the constant pressure process in the Brayton cycle?

    Heat is transferred.

    What are the two major application areas of gas turbine engines?

    Aircraft propulsion and electric power generation.

    What is recommended for using a regenerator in a turbine?

    Turbine exhaust temperature higher than compressor inlet temperature.

    What happens to the expansion process as the number of stages increases?

    It becomes isothermal.

    What is the typical pressure ratio for aircraft gas turbines?

    10 to 25.

    What was the bypass ratio of the first commercial high-bypass ratio engines?

    5.

    What happens to thermal efficiency with multistage expansion in an ideal Brayton cycle?

    It decreases.

    What are the applications of the Brayton cycle?

    Propulsion system, automotive turbine engines, aircraft turbine engines.

    What is used as a working fluid in high-temperature applications of vapor cycles?

    Mercury.

    What may drop during the isentropic expansion of superheated vapor in a turbine?

    Temperature and pressure.

    What percentage of turbine work output is required to operate the pump?

    0.04%.

    What decreases the moisture content of steam at the turbine exit?

    Superheating steam to higher temperature.

    What does regeneration help prevent in feedwater?

    Boiler corrosion.

    What can be applied in steam turbine cycle, gas turbine cycle, and combined cycle?

    Cogeneration plant.

    What happens to heat rejected in a Rankine cycle with fixed turbine inlet conditions when lowering condenser pressure?

    It decreases.

    What happens to pump work input in an ideal Rankine cycle with fixed boiler and condenser pressures when superheating steam?

    It remains the same.

    What happens to heat rejected when modifying the simple ideal Rankine cycle?

    It decreases.

    What are the components that exist before a combustion reaction called?

    Reactants.

    What is an obvious reason for incomplete combustion?

    Insufficient oxygen.

    What is the higher heating value when H2O in combustion products is in liquid form?

    It is higher.

    What device transfers heat from low temperature medium to a higher temperature one?

    Heat pump.

    What is the rule of thumb for COP improvement with temperature changes?

    Improves by 2 to 4%.

    What heating system is generally more expensive but saves money in the long run?

    Heat pumps.

    What is the most widely used absorption system in refrigeration?

    Ammonia-water system.

    What is true for all reversible heat engines operating between the same two reservoirs?

    They are the same.

    What is a process with no heat transfer called?

    Adiabatic process.

    What is the relative density of a substance compared to?

    Water.

    What type of heat exchanger allows fluids to flow at right angles to each other?

    Cross flow allows perpendicular fluid movement.

    What is the principle that states total energy in an energy system remains constant?

    Conservation of Energy ensures energy balance.

    What process has the same inlet and outlet enthalpies?

    Isenthalpic processes maintain enthalpy.

    What is the sum of energies of all molecules in a system?

    Internal energy includes various energy forms.

    What type of system is impervious to its surroundings?

    An isolated system has no mass or energy exchange.

    What device measures small and moderate pressure differences?

    A manometer is used for pressure measurement.

    What is a vapor with a temperature higher than its saturation temperature?

    Superheated vapor exceeds saturation conditions.

    What energy is possessed by a moving body due to its momentum?

    Kinetic energy relates to motion and speed.

    What thermodynamic process occurs at constant temperature?

    Isothermal processes have zero internal energy change.

    What is the function of a pump and compressor?

    They increase the total energy content of the flow.

    What law states not all heat can be converted to work?

    The 2nd law of thermodynamics limits energy conversion.

    What is the intensity of pressure measured above absolute zero?

    Absolute pressure includes atmospheric pressure.

    What is the ratio of useful horsepower developed by an engine?

    Brake thermal efficiency measures engine performance.

    What is flow work equal to?

    Flow work equals pressure times specific volume.

    What form of energy is due to position or elevation?

    Potential energy relates to height and gravity.

    What is another term for a constant volume process?

    Isometric, isochoric, and isovolumic are synonyms.

    What work is done during a reversible adiabatic expansion?

    Ideal work represents maximum energy output.

    What does the efficiency of the Carnot cycle depend on?

    Temperature differences affect Carnot efficiency.

    What is the heat required to vaporize a unit-mass of liquid?

    Latent heat of vaporization is crucial for phase change.

    What device measures temperature differences or high temperatures?

    A thermocouple is commonly used for temperature measurement.

    What science measures energy and enthalpy precisely?

    Calorimetry focuses on energy measurement.

    What is the rate of doing work per unit time?

    Power quantifies work done over time.

    What effect does superheating steam have on thermal efficiency?

    Thermal efficiency increases with superheating.

    What is the work done in pushing a fluid across a boundary?

    Flow work is essential for fluid dynamics.

    What is a liquid with a temperature lower than saturation temperature?

    Subcooled liquid is below boiling point.

    What type of boiler has water passing through tubes while flue gases burn outside?

    A water column boiler utilizes external combustion.

    What prevents damage to the boiler by warning of low water?

    A fusible plug provides safety against low water levels.

    What empties the boiler for cleaning and prevents impurity concentration?

    A blow-down line maintains boiler integrity.

    What device utilizes flue gases for feedwater preheating?

    An economizer recovers waste heat.

    What heat exchanger preheats air needed for combustion?

    An air preheater enhances combustion efficiency.

    What system protects furnace walls from high temperature?

    Waterwalls extend evaporative capacity.

    What is equivalent to generating 34.5 lbm/hr of steam at 212F?

    One Boiler Hp represents this energy output.

    What valve prevents boiler pressure from exceeding limits?

    A safety valve releases excess pressure.

    Where does water pass in a water tube boiler?

    Water flows inside the tubes for heating.

    What is the temperature at which air becomes saturated?

    Dew point temperature indicates saturation.

    What type of cooling tower has air moving horizontally?

    A cross flow cooling tower operates this way.

    What subject deals with the behavior of moist air?

    Psychrometry studies air moisture content.

    What is the ratio of water vapor mass to saturated air mass?

    Relative humidity measures moisture content.

    What air condition leads to water vapor condensation?

    Saturated air is at 100% relative humidity.

    What is the temperature difference in a cooling tower?

    Cooling range indicates temperature drop.

    What temperature indicates 100% relative humidity?

    Dewpoint temperature marks condensation onset.

    What is not a major part of the vapor compression system?

    Refrigerant is essential but not a system component.

    What refers to heat transfer due to dry-bulb temperature change?

    Sensible heating or cooling describes this process.

    What is a binary mixture of dry air and water vapor?

    Moist air contains both components.

    What temperature does an ordinary thermometer measure?

    Dry bulb temperature indicates air temperature.

    What is the mass of water in each kilogram of dry air?

    Humidity ratio quantifies moisture content.

    What system combines two vapor compression units?

    Cascade systems enhance cooling efficiency.

    What process increases humidity ratio at constant dry bulb temperature?

    Humidifying process adds moisture without temperature change.

    What is the ratio of partial pressure of water vapor to saturation pressure?

    Relative humidity indicates moisture level.

    What air conditioning process involves heating without moisture change?

    Sensible heating process maintains humidity.

    What process increases humidity ratio without changing dry-bulb temperature?

    Humidifying process adds moisture vertically.

    What temperature indicates condensation of water vapor in moist air?

    Dew point temperature signals condensation.

    What index measures refrigeration system performance?

    Coefficient of performance evaluates efficiency.

    What is the compression of gas in multiple cylinders?

    Multistage compression enhances efficiency.

    What is the transfer of energy between particles due to interaction?

    Conduction describes energy transfer through contact.

    What is the simultaneous control of temperature, humidity, and air movement?

    Air conditioning manages indoor climate.

    What is the non-condensing component of moist air?

    Dry air is the primary non-condensing element.

    What substance is used for heat transfer in a vapor compression system?

    Ammonia serves as the refrigerant.

    What is the pressure of refrigerant between the expansion valve and compressor intake?

    Low side pressure indicates suction side conditions.