Study of R-404A and R-448A refrigerants in low temperature refrigeration of electronics.

The more ecological alternatives to R-404A such is the R-448A, R-449A or R-452A are viable nonflammable fluids for low temperature refrigeration. Very low evaporation temperatures can be achieved with two-stage reciprocating compressors, which are commercially available from multiple large manufacturers. The combination of these fluids and two-stage compressions with inter-stage cooling enables low evaporation temperature down to -70°C. The ecological replacements for R-404A have many disadvantages including lower cooling capacities, very high temperature glides and high discharge temperatures. Number of studies has been presented recently but little attention has been paid to the low temperature applications outside commercial refrigeration. We present a comparison of R-448A and R-404A refrigerants to R-218, which can be taken as a benchmark fluid in our field of low temperature cooling of high-tech electronic devices like elementary particle detectors. Our measurements were performed using special oil-less experiment cooling circuit equipped with large number of pressure and temperature sensor, flowmeters, etc. We have used Roman Pot detectors as a real power load that is installed in the Large Hadron Collider tunnel at CERN.