DuPont/ASHRAE classifications confuse me

[MichaelThomasGreer]

Hi there, new member I am.

 

I've been working with refrigerants in code, and I've been learning a lot.

 

Alas, I never did too well in chemistry.

 

 

Refrigerants have standard naming conventions, like R-134a, which gives you exactly which and how-many of H, Cl, F, and C are present. You can also plug an oxygen atom in there by prefixing an E onto the number: R-E134. And you can turn any one of those into a halon by replacing one or more atoms with Br (like R-13B1, which is H-1301). Bromine is evil, of course, but that's not my problem. (Oh, you can also write dashes between digits to accommodate things with more than a single-digit's worth of atoms. Hence R-134a could technically be written R-1-3-4a.) And the little letters at the end are isomers -- numbered by increasing variability in the distribution of atomic mass.

 

Certain names confuse me. Such as R-FE-36. I understand that's a DuPont trade name, but I still don't get it. Where does the "FE" come from? (How can I decode that algorithmically?)

 

The main reason for my post is confusion about azeotrophic (400-series) and zeotrophic (500-series) blends, and miscellaneous organic (600-series), inorganic (700-series) and unsaturated organic (1000-series) compounds.

 

I realize that they are just reusing numbers that are not commonly used otherwise. For example, the only useful refrigerant I know of that has a standard name in the 400 series is R-4-1-12, and the presence of dashes kind of obviates the possibility that it is a compound's ASHRAE registry number.

 

R-600 confuses me. Why not just write it as R-3-11-0? Would that be incorrect? (Here my lack with chemistry shows. Are they different molecules?)

 

 

The thing I am trying to accomplish is to write some software that will confirm a text string as a valid refrigerant name, without needing a large (and necessarily incomplete) database of refrigerants. I don't care to decode stuff in the various overloaded series -- only to be able to properly distinguish them from actual refrigerant codes (verses a registry number). Oh, and without case-sensitivity being an issue. (The code fixes capitalization for the user.)

 

Thank you for taking the time to read this. If you know anything about refrigerants, please help.