NEW REFRIGERANTS – NEW OILS
However, another transition is already taking place. The HFC refrigerants that were introduced are being replaced by natural refrigerants such as carbon dioxide (CO2), hydrocarbon refrigerants (e. g. propane, propene) and ammonia (NH3). In addition, fluorinated olefins (HFO) will be used in many applications in the future. Why?
The HFCs did not do any more damage to the ozone layer, but they did have a negative impact on global warming. Their global warming potential (GWP) is high, at between 1,000 and 4,000. Fluorinated olefins have a significantly lower GWP. The existing refrigeration oils have to be tested for compatibility and miscibility with these new substances and their compounds, and if necessary, adjusted. This creates new market opportunities for lubricant manufacturers such as FUCHS.
Natural refrigerants such as CO2 and ammonia also need an optimal refrigeration oil. “Some special products from our RENISO C range work very well in conjunction with the refrigerant CO2,” says Wolfgang Bock and adds: “Generally speaking, you have to keep cool and maintain a clear focus to make sure that you do not lose sight of the big picture.”
The right refrigeration oil for the respective refrigerant is so important because both have a direct impact on the compressor mechanism, the “driving force” in the refrigerant circuit. A suitable refrigeration oil forms a homogeneous mixture with the respective refrigerant and provides the compressor’s moving parts with reliable protection against wear. It has to demonstrate a defined viscosity and should not be too viscous because without the corresponding fluidity, it will be unable to move properly at low temperatures through the refrigerant circuit and disturb operation of the refrigerating unit.