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pressure temperture correlation

Can someone please explain the pressure temperature correlation of refrigerant

2. The higher the temp/ the higher the pressure.

3. and the lower the pressure the lower the temperature.

This might help : http://www.chm.davidson.edu/Chemistr...Theory/PT.html

4. However

When you take Hydrogen at a high pressure, say 700# then drop it to say 5#, it will actually heat up.

5. Any gas that will condense to liquid has a pressure/temp chart. In other words they are very predictable. I have a friend who delivers liquid Nitrogen. I have no ides what the pressure is at 75 degrees, but it is in the thousands of PSI. He hauls it in an insulate thank with a pop off valve that is set for very low pressure, I think it is under 10psi. As it pops off, it cools the liquid and maintains the low pressure and extremely low temp.
The most interesting thing about pressure/temp charts for different gases is they are each very unique. No two are exactly alike.
If you mix any two gases, one of two things will happen. Either they will occupy the space as two separate gases as the 400 series of refrigerants each condensing and evaporating at a different pressure/temp, or they will mix to form a new gas as in the 500 series of refrigerants, which evap and condense at the same pressure/temp.
However, even tho the gases may condense at a different rate, once both are condensed, the liquid will mix.

6. Jax

You are absolutely

correct. Dont forget about the partial pressure. Every thing wants to come too equilibrium. It is ok.

7. and when you take those laws and apply them , you can get refrigeration.

8. Originally Posted by acmanko
and when you take those laws and apply them , you can get refrigeration.
or

you can cook meat in a liquid at a higher temperature than boiling point.

9. If you take hexane at 3500 psig and drop it to 100 psig it it will heat up also. Some things under pressure and released tend to act differently. Hexane at 3500 psig dropped to 2000 psig, there is a cooling effect.

10. Hexane///////

11. This is the answer to all that ails you concerning pressure, temperature and volume. You really should include volume with press/temp. The whole reason mechanical ACR works is because of a volume change.

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

Here is another concerning aziatropes or blends:

http://en.wikipedia.org/wiki/Dalton's_law

And last but not least:

http://en.wikipedia.org/wiki/Henry%27s_law
Last edited by gruntly; 09-27-2007 at 01:22 AM.

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Here is another place to look and read: http://www.refrigerants.com/frame.htm

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