Refrigeration principles Flashcards
1
Q
What is the effect of low pressure on boiling water?
A
- Volume of water increases (less squeezing of molecules)
- The energy required to free the water molecules from their attracting forces (boil) is less
2
Q
What is the effect of increased pressure on boiling water?
A
- Volume is less (Molecules squeezed together)
- Energy required for molecules to ‘break free’ is increased
- Boiling point increased
3
Q
What is the fundamental principle of refridgeration?
A
A hot body has more energy than a cold one and will always give up this energy to excite the molecules of the colder body.
4
Q
Describe Sensible Heat
A
- Temp rises
- State is unchanged
5
Q
Describe Latent heat
A
- Temp unchanged
- State changes
6
Q
Describe Superheat
A
Every degree over 100c is superheat,
ie:105c is 5c of superheat
7
Q
Describe Subcooling
A
- Extracting heat from superheat ie:taking superheated steam from 120c to 100c is adding 20c of subcooling
