Flooded Evaporator fundamentals

[sgtech]

Hi


This is a industrial refrigeration system that uses flooded evaporator and accumulator, in the tube is of the evaporator is glycol and shell side R22 *****, ***** temperature at about 45 degrees celcius and 17.64kg/cm2A from the condenser then routed through the filter dryer then pass the level control valve then to the evaporator.

Tube side is glycol at 12.8 degree celcius and is being cooled to about 5.5degrees celcius. Boiled off ***** vapour is drawn to the suction port at 3.33degrees celcius at 5.2kg/cm2G.

How does this evaporation cooling works ? Whats the difference between boiling and evaporation ? the ***** temperature is high when it enters the evaporator and together with the glycol, the ***** temperature should increase right ? since there is so much heat.

When the ***** boil the temperature should be the same as the liquid ? I'm so confused. Water is heated, it boils i don't see the temperature of the water is reduced. im am extremely confuse.

[Brian_UK]

The refrigerant is boiling because the pressure has been reduced by the suction from the compressor.

Same effect as having an expansion valve in 'regular' evaporator.

[bill1983]

hi sgtech
"Whats the difference between boiling and evaporation ?"
effectively nothing; The boiling point of a liquid or its evaporation point are the same.
In refrigeration, the evaporation point of a liquid is dependent on the pressure exerted upon it. The amount of evaporation depends upon the heat load supplied.
In your question, the ***** vapour temperature at the compressor is a result of the reduced pressure exerted on the liquid and the heat load from the glycol.
if you read this thread it will begin to explain it better than i can:http://www.refrigeration-engineer.com/forums/showthread.php?t=28659
then go to this thread:http://www.refrigeration-engineer.com/forums/showthread.php?t=19701
feel free to return to post more questions on this matter.