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frankiee
07-01-2006, 03:32 PM
Hi
I am new here
I am not use to the site yet and I was searching for a "pressure/ enthalpy chart for refrigerant 12
I found the heading in the site which I have listed below, but I was unable to open it.

Links and Downloads Database
Pressure-Enthalpy Chart

My request is if any body can lead me to a P/h chart for refrigerant 12
My instructor gave us one which is barely readable so I got one from the net BUT, the
KJ/Kg is way off base.
I do not understand and my instructor can not say why.

I am in 3rd year marine engineering and doing air conditioning in my 3rd thermodynamics.
The chart which is barely legible, that our instructor handed out, works with our calculations from the text book (Basic Engineering Thermodynamics by Rayner Joel) so we will be using it to prepare for our 1st class Marine Engineering test after graduation.

I would like to find a chart that I can see clearly and that has the proper enthalpy scale.
Thank you in advance

I hope to add to the forum on a regular basis.:)

US Iceman
07-01-2006, 03:44 PM
Welcome to the forum,

You said the enthalpies were not correct on one of the charts. My question is, how are they not correct? Do they not compare favorably to another chart?

One thing you should be aware of on these charts is that they can be different. Sometimes the charts (and tables for that matter) can be based on different reference temperatures.

In some charts, the zero enthalpy is based on Zero, in others the reference temperature is -40. If you compare one enthalpy from one chart to another chart, it is possible that the enthalpies for the same point will be different. Same for some refrigerant tables.

Whenever you are doing mass flow calculations or other procedures using the refrigerant PH chart or tables, you need to make sure that the Zero enthalpy reference is the same.

DO NOT use different charts or tables as they will lead you to make incorrect calculations.

I suspect this is the problem you are experiencing.

As to the problem of the link not working, I will have to check this. It worked when I posted it, but for some reason is not, now.

frank
07-01-2006, 04:50 PM
http://www.et.web.mek.dtu.dk/Coolpack/UK/download.html

Download COOLPACK and within the program go to Refrigeration Utilities.

You can print off P/T charts for any refrigerant

frank
07-01-2006, 04:52 PM
OOps sorry

Just noticed at the bottom of the page you can download Refig Utilities seperately :o

frankiee
09-01-2006, 11:38 PM
Thank you everyone

marianstancu
11-01-2006, 07:29 PM
Hi,
I need the Molier diagram (T-s) for water. Please help me

US Iceman
11-01-2006, 08:25 PM
Hi marianstancu,

Here is a copy of the information you requested. I hope this is useful.

Best Regards,
US Iceman

TXiceman
12-01-2006, 02:56 AM
Something I remember from days gone bye...especially on R-12, different manufacturers of the refrigerant used a different base line for the R-12 and had different enthalphy valuses at a specific condition. When you are working on a heat balance, all you are concerned with the the differences in enthalphy anyway.

Ken

marianstancu
12-01-2006, 08:06 AM
Thank you US Iceman.
Best regards, Marian

JORGE
20-09-2006, 02:53 PM
Hi! Thank You Us Iceman
Jorge

lucky_jenie
01-02-2008, 01:50 PM
Thanks, im need it to do my report.

Greener
24-02-2010, 01:57 PM
Something I remember from days gone bye...especially on R-12, different manufacturers of the refrigerant used a different base line for the R-12 and had different enthalphy valuses at a specific condition. When you are working on a heat balance, all you are concerned with the the differences in enthalphy anyway.

Ken

Hello,

I also have found that different manufacturers and textbooks use different reference temperatures for their p/h diagrams.

Can anybody tell me why this is?

Coolpack seems to match the enthalpies to the relevant saturation temperature / pressure. Why isn't this the case for all other p/h diagrams?

Thank you.