Refrigeration Cycle

Here you go, click this link. Link

Hope it helps.

Any refrigeration cycle is just a machine that "moves heat". It moves that heat from a place you don't want it to a place that's less objectionable. This can confuse some people because they think a refrigeration cycle is something that makes "cold". That's wrong. The above drawing illustrates a typical refrigeration cycle. If you look at #4 you'll see the evaporator. Although the inside of the evaporator has violent boiling of refrigerant in it this is the part of the machine that actually gets cold (if you remove heat, what you're left with is something colder).

In the evaporator we see liquid changing state, from liquid to vapor. This change of state is the refrigeration "magic". For any liquid to change state to vapor a lot of heat must be added to that liquid. An example of this would be the following. To change 1 lbs. of water to 1 lbs of steam requires 965 BTU's. Anywhere from 32 degrees (0 for you Celsius fans) to 211 degrees you can raise the temperature of that same water 1 degree with just 1 BTU. So that 1 lbs of water at 32 degrees could be raised to 212 with just 180 BTU's. 180 BTU's will get it from the state of being solid (ice) to the verge of being a vapor (steam). But it takes 965 BTU's to make it boil. This boiling principal is what makes the cycle work for us.

So if we pass warm across the evaporator and the refrigerant inside the evaporator needs a lot of heat in order for it to boil, we use that. The boiling action pulls the heat it needs from the warm air we send across the evaporator. The air gets colder!

If you look at #1 you see the heart of our system, the compressor. The compressor is a vapor pump. It roughly boosts the pressure of our system 3:1. It take a low pressure low temperature gas and boosts it to a high temperature high pressure gas and sends that gas to the condenser.

The condenser #2 has 2 jobs. First the condenser is the place we get rid of the heat we picked up in the evaporator. If you put your hand near the condenser and feel warm air, this is the warmth we just picked up in the evaporator. The condenser rejects that heat for us. At the same time it does it's second job. The condenser removes enough heat so that our high temperature high pressure gas becomes a high pressure high temperature LIQUID. Now the cycle is ready to begin all over again. The liquid refrigerant is held under pressure by #3, the metering device.

When the liquid passes the meter device the pressure suddenly drops and the refrigerant immediately starts to boil. This is a closed system. The same refrigerant might travel around and around for decades moving heat and making our lives more comfortable.

If you have any further questions ask Mr Tornando, he knows all about this heat moving stuff.