REFRIGERATION OILS FOR THE NATURAL REFRIGERANTS ISO-BUTANE AND CARBON DIOXIDE

摘要

Natural refrigerants with low global warming potential are getting more and more important. rnExamples are hydrocarbons like iso-butane(R600a)as the main refrigerant for household refrigerators and carbon dioxide(R744)with a lot of different applications like supermarket or ship cooling. rnThe manuscript describes suitable lubricants for cooling systems with these refrigerants. rnFor R600a mineral oils with excellent cold flow behaviour and with an additive system that enhances lubrication properties are used. rnPolyol esters(POE)are the first choice for CO_2 applications because of their good refrigerant miscibility and high thermal stability.Special antiwear(AW)additives guarantee lubrication under both sub-and transcritical conditions.