what is phase change?

just wondering thanks

its when the liquid boils off into a gas. thats what most refrigeration is based on

Defined: a change from one state (solid or liquid or gas) to another without a change in chemical composition

*But when talking about computers we are referring to when a liquid changes to a gas and back again. The lower the boiling point (temperature when it turns from a liquid into a gas) the colder the surface that can be produced

how it's applied to cooling: when a liquid goes to a gas, it takes in heat. so when the coolant flows through the capilary, it goes into an area with lower preasure, allowing it to boil. in boiling, it goes from liquid to gas, taking in heat. then in the compressor, it gets back to a higher preasure area, causing it to condense back into a liquid, in the condensor coils. then it goes back to the capilary, and repeats the process.