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latent heat
17-03-2006, 10:54 PM
I have a question in regaurds to pressure/temperature relationship. We all know that when it comes to Sensible Heat, pressure and temperature are directly perportional as pressure rises the boiling temperature or saturation temperature also rises. And when it comes to Latent Heat pressure and temperature are indirectly perportional. As pressure rises latent heat of vaporization per Lb. falls. until a substance or refrigerant reaches its critical pressure. But my question is does the specific heat value of a substance change with pressure and if so how and in what way????

Dan
18-03-2006, 02:23 AM
I would think that specific heat increases with pressure as a result of increased density.

Andy
18-03-2006, 10:08 AM
Hi Latent Heat:)

Look under the Forum section that shows the software downloads for a program Ref Utilities, you can model this with all sort of refrigerants using this program:)

I have not checked what the sensible heat capacity does with pressure, but I would assume density is the deciding factor.

Kind Regards Andy.:)

latent heat
19-03-2006, 06:16 PM
Thanks Andy, as far as sensible heat goes we know it is directly proportional with pressure. The thing iam concerned with is the specific heat value and after looking into it from what I have found it looks like the specific heat value follows the same rules as sensible heat and opposite of latent heat.

Johnny Rod
20-03-2006, 12:28 PM
Perhaps this is a misunderstanding of terms? Specific heat capacity is the amount of energy (Joules) per weight (kilo) to give a temperature rise (degrees C). This is the same as sensible heat, i.e. energy in, temp goes up.

Andy
21-03-2006, 11:19 PM
Perhaps this is a misunderstanding of terms? Specific heat capacity is the amount of energy (Joules) per weight (kilo) to give a temperature rise (degrees C). This is the same as sensible heat, i.e. energy in, temp goes up.
Specific heat is the correct term. Sensible is a heat capacity of a product.

Kind Regards. Andy