Unit 3 - Refrigeration and Cooling. Flashcards
One ton of refrigeration.
The amount of heat required to melt 1 ton of ice in a 24 hour period.
Refrigeration
The process of removing heat from a place where it is not wanted and transferring that heat to a place where it makes little or no difference.
1 ton of refrigeration = ____ BTU
12,000
Name three reasons why ice melts in an icebox.
It takes heat from food
Infiltration when you open the door
Heat travels through the walls
What are the approximate temperatures ranged for low medium and high temp refrigeration applications.
Low 0% and down
Med 0%-45%
High 45% and up
%=degrees
What does the compressor do in the refrigeration system?
It converts low pressure and low temperature vapor from the evaporator and makes it a high temperature and high pressure vapor.
Define superheated vapor.
It is the difference between the latent heat in the evaporator coils and the sensible heat in the vapor line before the compressor.
Define there’s sub-cooled liquid
The difference between the
What is meant by saturated liquid and vapor?
Saturated refrigerant which is vapor and liquid.
What is meant by de super heating a vapor.
Cooling of the vapor.
What happens to refrigerant in the condenser?
It changes from a vapor to a liquid and releases heat outside.
The metering device____
Meters refrigerant.
Describe flash gas and how it affects the system.
Answer.
Quality means ____ when referring to a refrigerant.
Degree of Saturation
Describe the difference between a reciprocating compressor and a rotary compressor.
Recip pistons
