3. Special study of refrigerated compressions

As shown in previous developments and particularly in figure 16 , cooled compressions consume less mechanical energy than uncooled or slightly cooled compressions. In practice, therefore, as soon as the power required is substantial (a few kilowatts), the gas is cooled during compression. Two types of cooling are used, separately or simultaneously: continuous cooling or continuous refrigeration, on the one hand, and fractionated refrigeration, on the other.