Mechanical Engineering Board Review - Power & Plant Engineering Flashcards

Vocabulary flashcards generated from mechanical engineering board review questions covering thermodynamics, power plant systems, refrigeration, fluid mechanics, and HVAC.

Rotary dryer

The most common dryer used in industry, consisting of a rotating cylinder inside which materials flow while coming in direct contact with hot gas.

Relative humidity

The ratio of the mass of water vapor in air to the mass of water vapor in the air if it were saturated at the same condition.

Cascade refrigeration cycle

A refrigeration cycle often used in industrial processes where objects must be cooled to temperatures below $-46^\text{o}C$.

Cohesion

A fluid property referring to the intermolecular attraction by which separate particles of the fluid are held together.

Binary geothermal plant

A type of geothermal power plant utilized when there is a presence of brine extracted from underground.

Exothermic reaction

A chemical reaction during which chemical energy is released in the form of heat.

Open heater (Deaerator)

A direct-contact feedwater heater used to strip dissolved corrosive gases like $O_2$ and $CO_2$ from water.

Means of egress

A continuous and unobstructed path of travel from any point in a building or structure to a public way.

Pressure-imposing element

Any device or portion of refrigeration equipment used to increase refrigerant pressure.

Zeotropic blend

A refrigerant mixture comprising multiple components of different volatilities that change volumetric composition and saturation temperature as they boil or condense at constant pressure.

Gasohol

A fuel blend containing 90% gasoline and 10% ethanol.

Emulsion

A stable suspension of a finely divided fluid in another immiscible fluid.

Once-through boiler

A high-pressure boiler system characterized by having no steam drum (drumless boiler).

Desuperheater

A device that reduces steam temperature by spraying low-temperature water from the boiler drum into the superheated steam flow.

Deriaz turbine

A type of water turbine configured specifically for diagonal flow.

Morse test

A test method used to measure the indicated power of a multi-cylinder internal combustion engine.

Center of pressure

The point on a submerged plane surface where the total resultant hydrostatic force acts.

Isochronous governor

A governor designed to operate with 0% speed regulation, maintaining constant speed under all loads.

Sublimation

The phase transition of a substance directly from the solid phase to the vapor phase without passing through a liquid state.

Convection

The mode of energy transfer between a solid surface and an adjacent moving fluid, combining the effects of conduction and bulk fluid motion.

Quasi-equilibrium process

A thermodynamic process in which the system remains infinitesimally close to an equilibrium state at all times.

Turbocharging

A forced induction method where a turbine driven by engine exhaust gases powers a compressor to force additional air into the inlet cylinder.

Stagnation temperature

The temperature an ideal gas attains when brought to rest adiabatically.

Azeotropes

Refrigerant mixtures of different components that evaporate and condense as a single substance without changing composition.

Isomers

Chemical compounds with identical molecular formulas but distinct structural arrangements (e.g., R-134 and R-134a).

Blast freezing

A quick-freezing method using a high-velocity stream of cold air to achieve high heat transfer rates from a product.

Energy Efficiency Ratio (EER)

The ratio of useful cooling capacity in $\text{Btu/hr}$ to the total electrical power input in Watts.

Scavenging

The process of pushing burned exhaust gases out of an engine cylinder using a fresh charge of air or air-fuel mixture.

Mean radiant temperature

The uniform surface temperature of an imaginary enclosure in which an occupant would exchange the same amount of radiant heat as in the actual complex environment.

Vernon's globe thermometer

An instrument consisting of a 6-inch hollow copper sphere painted flat black with a temperature sensor at its center, used to estimate mean radiant temperature.

Fenestration

Any glazed opening in a building envelope, including windows, skylights, framing, dividers, and associated shading devices.

Cooling load

The rate at which sensible and latent heat must be removed from a conditioned space to maintain designated indoor temperature and humidity levels.

Hygroscopic materials

Substances whose moisture content varies readily depending on the ambient relative humidity and temperature conditions.

Regain

The moisture content of a hygroscopic material expressed as a percentage of its dry weight.

Tray dryer

A batch dryer in which materials are spread on removable trays inside an enclosed chamber where hot air circulates.