Energy Saving in Sliding Vane Rotary Compressors

Electrical energy for producing compressed air in industrial contexts represents an important share of the overall electricity consumption: this figure accounts for 4-5%. Compressed air is produced by means of rotary volumetric machines which are proven to be more suitable than other types (dynamic, reciprocating, etc…) in terms of pressure and flow rate delivered. Sliding Vane Rotary Compressors (SVRC) compared to screw type compressors are not as widespread. However, thanks to the technological development made in the last two decades, they are characterized by premium specific energy consumption and demonstrate unforeseen potential in terms of energy saving due to some intrinsic features specifically related to this machine. The paper focuses the attention on a new technology under development related to the oil injection inside the machine able to cool the air during compression. A comparison between the results of a mathematical model of the new injection oil technology and experimental p-V measured by means of piezoelectric transducers is shown. The compression work reduction measured on the shaft and observed integrating the p-V cycle gives a strong consistency to the modelling toward a comprehensive physically consistent software platform and to the injection technology.