Definitions Flashcards
Temperature
A word used to describe the level of molecular activity expressed in Fahrenheit Rankin Celsius or kelvin
British thermal unit
The amount of heat required to raise 1 lb of water to 1°F
Conduction
Heat transfer from one molecule to another within a substance or from one substance to another
Convection
Heat transfer from one place to another using a fluid medium
Radiation
Heat transfer, heat that passes through air heating solid objects that in turn heat the surrounding area
Sensible heat
Heat that causes a change in temperature
Enthalpy
The amount of heat a substance contains from a predetermined base or point
Latent heat
Hidden heat or heat energy being added but no temperature rise occurring
Latent heat of vaporization
The latent heat absorbed when refrigerant evaporates.
Latent heat of condensation
The latent heat given off when refrigerant condenses
Specific heat
The difference in heat rise
Refrigeration
The process of removing heat from a place where it’s not wanted and transfer it to somewhere that it does not matter
Specific volume
The volume occupied by 1 lb of a fluid
Dalton’s law
Gas law that states that the total pressure averted buy a gas mixture is the sum of the pressure of the individual gases
Compressor
A vapor pump that pumps vapor from one pressure level to a higher pressure level
Condenser
The component in a refrigeration cycle that transfers heat from the system by condensing a refrigerant
Evaporator
The component in a refrigeration system that absorbs heat into the system and evaporate the liquid refrigerant
Metering device
A valve or small fixed size tubing or orifice that meter liquid refrigerant into evaporator
Net refrigeration affect
Is expressed in BTU per pound and is the quantity of heat that each pound of refrigerant absorbs from refrigerated space to produce useful cooling
Saturated
When a liquid is saturated - both the vapor and liquid can exist simultaneously.
Saturation temperature
The temperature at which a refrigerant will change state.
Sub cooled
The temperature of the liquid when it is cooled below its condensing temperature.
Superheated
The temperature of vapor refrigerant above it saturation temperature.
Temperature pressure relationship
Refers to Temperature pressure relationship of the liquid and vapor in a closed container
