How can we reduce the contaminating influence of the lubricating oil in the refrigeration plant?
1. By choosing lubrication oil that dissolves totally in the refrigerant in combination with a properly functioning oil return. 2. And with insoluble oil: • by choosing a compressor with low oil consumption*, • by using a high-efficiency oil separator, • by using a compressed gas cooler for the oil separator, at high oil vapour content and/or • by using an oil with low vapour pressure and high mol mass*, • by arranging the liquid tank so that oil can settle and be returned to the compressor(s); for 2-stage plants this also applies to the intermediate tank(s), • by regularly draining off the oil, automatically or otherwise. 1. Oil return for oil soluble in refrigerant The design of direct expansion (DX) systems is based on oil returning via the suction line(s). This works on the principle that the speed (impulse) of the gas is so high that the liquid present in a film along the pipe wall is dragged along as well. This is at the expense of pressure loss and therefore energy. If you step
