Evaluating lubricants for lower GWP refrigerant compressor operation.

Summary of an interesting paper from the recent Purdue conference.
The 478 papers from Purdue IIR-cosponsored conferences are now available in Fridoc database by using the following direct links. IIR members are entitled to a number of free downloads. Don’t forget to login or register first!    
16th International Refrigeration and Air-Conditioning Conference
23rd International Compressor Engineering Conference
4th International High Performance Buildings Conference


We present here an interesting paper from the second conference:

Evaluating lubricants for lower GWP refrigerant compressor operation

Lubricants are an essential component to refrigerant compressor operation, regardless of the refrigerant used. But to maintain a reliable and efficient operation, the choice of the lubricant can vary depending on the type of compressor, the design of the system and mostly the kind of refrigerant.
This paper evaluates five potential candidates as substitutes for R-404A and the potential impact of lubricant chemistry. The refrigerants considered are three non-flammable HFO/HFC (R448A, R449A, R452A), one slightly flammable HFO/HFC/CO2 blend candidate (R455A) and one flammable HC candidate (R290). Investigation is made on how these refrigerants interact with lubricants (miscibility, solubility, system performance) and if current marketed lubricants used with R-404A are still good candidates to use with these lower GWP candidates.
Polyolester (POE) lubricant currently used with R-404A in compressor operation is found to be satisfactory for use with most of the refrigerants investigated and has no negative effect on performance. By using ISO 22 POE lubricant, the effectiveness of R290 when compared to R404A shows better efficiency (+11%) but some capacity loss (-10%), which could be mainly from thermodynamics, but R290 high solubility level could be playing a role. Lubricants like mineral oils, which typically have been unacceptable for use with R-404A due to miscibility concerns, are also not miscible with the HFO/HFC refrigerants studied.

Joseph A. Karnaz (2016). Evaluating Lubricants for Lower GWP Refrigerant Compressor Operation. Paper presented at the 23th International Compressor Engineering Conference. Purdue, United States.
Direct link to the paper in Fridoc, click here.