Refrigeration cycle

Question 1

Describe refridgerant

Answer 1

• R134A
• Boiling point of -26.5c
• Refridgerant is very cold so it will extract the heat from inside the refridgerator,as heat travels from hot to cold

Question 2

Describe Compressor (Refridgeration)

Answer 2

• Enters as a LP,warm gas leaves as HP,hot gas
• Gas is compresssed so it will heat up & allow conduction to happen at condenser(gas must be hotter than the temp of the room or heat will not travel hot to cold)
• It is the motive force in the system

Question 3

Describe Condenser

Answer 3

• Where heat collected in the evaporator is dumped into the S/W heat exchanger.
• Enters as a HP,hot gas as it is cooled it becomes a HP/warm liquid
  As RF condenses into a liquid it gives off heat

Question 4

Describe Thermal expansion valve

Answer 4

Because the TEV restricts the flow of RF,there will be less RF leaving the TEV, so it will have room to expand,causing the molecules inside to move apart,dropping the temp & pressure

Question 5

Describe the Bulb & Tube in a TEV

Answer 5

• Inside the TEV is a diaphram which is connected to a thermal bulb at the exit of the Evap,it is connected to TEV by a tube
• Inside the bulb there is RF & depending on the temp of RF leaving the Evap will expand or contract
• This change in pressure will travel along the tube to the TEV and move the diaphram up & down. Which will allow more or less RF to pass through TEV

Question 6

Describe Evaporator

Answer 6

• Refridgerant enters as a LP, cold liquid
• Fan blows warm air from the room across the coils carrying RF,allowing the air to give up its heat
• The RF will begin to boil & will turn into a gas
• RF has a very low boiling point (R134A boiling point of -26.5 degrees)
• RF leaves as a LP,warm gas

Refridgerant steals heat from air leaving it cold