REPLACEMENT OF REFRIGERANT R-12/R-22 BASED COOLING SYSTEMS FOR MISSILE GUIDANCE SYSTEMS

THE IMMINENT PHASE-OUT OF CHLOROFLUOROCARBON (CFC) REFRIGERANTS, IN PARTICULAR CFC-12, NECESSITATES IDENTIFICATION OF A SUITABLE ALTERNATIVE REFRIGERANT WHICH IS ATMOSPHERICALLY BENIGN. FOR MANY NEW EQUIPMENT APPLICATIONS, HFC-134A HAS EMERGED AS THE COMPOUND OF CHOICE DUE TO THERMODYNAMIC PROPERTIES SIMILAR TO CFC-12, ZERO OZONE DEPLETION POTENTIAL AND LOW GREENHOUSE WARMING POTENTIAL. FOR EXISTING CFC-12 EQUIPMENT, THE MOST DESIRABLE COURSE OF ACTION IS TO IDENTIFY A DROP-IN REPLACEMENT REFRIGERANT; SUCH HAS NOT TO DATE BEEN FOUND, AND IT IS UNLIKELY THAT SUCH A REFRIGERANT WILL BE FOUND. IT IS TECHNICALLY FEASIBLE, HOWEVER, TO REMOVE THE CFC-12 AND ACCOMPANYING LUBRICANT, RECHARGE WITH HFC-134A AND A COMPATIBLE LUBRICANT, THUS RETROFITTING THE SYSTEM WITHOUT MAJOR EQUIPMENT MODIFICATION OR REPLACEMENT. A PROGRAM TO ADDRESS THE QUESTIONS CONCERNING COMPATIBILITY, PERFORMANCE AND RELIABILITY ASSOCIATED WITH SUCH A RETROFIT IS GIVEN IN THIS PROPOSAL.