The Science of Heat Transfer: Understanding Refrigeration Process

[scar123]

Heat does not naturally flow from a cool body to a hot body. A
refrigerator, however, does remove heat from the icebox and expels it as
warm air to the outside world. What is required to make this process
function?

 

[John Creighto]

http://en.wikipedia.org/wiki/Refrigeration_cycle

 

[scar123]

would conduction be a good answer to this?

 

[John Creighto]

would conduction be a good answer to this?

Well, obviously without conduction you won't be able to transfer the heat the refrigeration fluid. The rate of conduction depends on the temperature difference. The temperature difference is created because gases cool as they expand.

 

[John Creighto]

would conduction be a good answer to this?

Well, obviously without conduction you won't be able to transfer the heat the refrigeration fluid. The rate of conduction depends on the temperature difference. The temperature difference is created because the refrigeration fluid cools as it expands.

 

[scar123]

So conduction would be the answer to this? WHich is better answer though, Conduction or 2nd law of thermodynamics?

 

[physixguru]

So conduction would be the answer to this? WHich is better answer though, Conduction or 2nd law of thermodynamics?

The working principle of a refrigerator
Heat is removed from food and the surrounding area, thereby creating an environment which retards the activity of microorganisms. Temperature is usually about 5°C.

A refrigerant is used to remove the heat, i.e., a highly sensitive liquid which converts easily into a gas and back again into a liquid, e.g., freon12 or ammonia.

The refrigerant is carried in tubes at the back of the appliance and around the icebox.

The electric motor activates the compressor in the appliance which forces a gaseous refrigerant in the compressor into the condenser. In the condenser the refrigerant changes into a liquid, heat from the food in the refrigerator is absorbed by the liquid refrigerant and converts it back into a gas, ready for the cycle to begin again. In so doing, the food is cooled.

The refrigerator is thermostatically controlled to ensure an even temperature.

NOW WHAT DO YOU THINK BEST DESCRIBES THIS PROCESS.?

 

[scar123]

Conduction?

 

[physixguru]

yupp...