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nh3simman
26-03-2007, 08:48 AM
We use refrigerant properties regularly to model system performance. The EOS and other property models used by the NIST and the measuring techniques ensure the most accurate representations.

But, these are for pure refrigerants!!!

In 1983, Dr John McMullan at Ulster University in Northern Ireland did a research project where he introduced different quantities of oil into a test rig and measured the performance.

In his work, John produced the p-h diagram for refrigerant with an oil mixture.

http://www.technisolve.co.za/images/R22with10pcOil.png

The attached picture is R12 with 10% oil. The striking thing to note here is the lack of vapor line.

The team at Ulster went further and compared the measurements with a computer model and produced excellent correlation.

The work was sponsored by the Commission for the European Communities and resulted in a final report dated December 1983. Contract EEA-4-028-GB.

In optimizing the performance of big systems, we know the significance of the compressor. It seems odd to me that this effect has not been explored further.