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[Araboni]

Dear all

As per attached diagram, we in our plant intend to cool two streams of styrene monomer and 1,3 butadiene using a refrigeration package. The depicted exchangers are already available, whereas we need to buy a convenient refrigeration package. I just theoretically calculated two refrigerants of R22 and Ammonia and found that the compressor power in case of R22 is somehow 4-5 times more than that of Ammonia due to their heat of vaporization difference.

1. Could anybody inform me if in practice I’m correct?
2. Is there any software or catalog by which I can in practice compare the refrigeration performance of Ammonia and Freon?
3. If you all were us , what would you do ?

Attached Files

•  Refrigeration diagram.xlsx   29.28KB   36 downloads

[Art Montemayor]

Araboni:

 

I would never select a Freon (particularly R-22) as an industrial refrigerant if I could use ammonia.  I have made many ammonia and Freon refrigeration calculations in the past as well as process and mechanical designs and have always had ammonia come up on top as the preferred and optimum refrigerant fluid.  The cooling range I have worked in has been between +5 ^oC down to -32 ^oC.

 

Thre is no software, to my knowledge, that compares the performance of ammonia and the Freons.  What is done is that each unique refrigeration cycle is calculated as to its heat and material balance and a C.O.P. (Coefficient of Performance) is developed.  What you usually find out is that ammonia beats them all in HP/ton refrigeration.  However, do not forget the other important features of a good refrigerant:

• Good, dependable availability;
• Good, low price;
• Acceptable environmental results (no ozone damage, no global warming, etc.,)
• No flammability or explosive properties.
• No chemical decomposition.

 Ammonia, you will find, meets all the above criteria.  If you can’t decide what to do after considering all the above, I don’t know what else to tell you.