Sliding Vane Rotary Compressor Energy Optimization

Abstract

The reduction of the electrical energy for producing compressed air gives an important contribution to the overall energy saving in the industrial context. Among the different technologies, Sliding Vane Rotary Compressors (SVRC) demonstrate unforeseen potential in terms of energy saving due to some intrinsic features specifically related to this machine. One of the most important contribution is given by cooling the air during compression; this could be achieved by a proper oil injection conceived for this purpose. A mathematical model describing the oil injection process is presented in this paper. It considers the main parameters which describe the spray formation, its penetration inside the cell till to the intersection with metallic surfaces and the resulting air cooling. The influence of the most important design and operating injection parameters have been checked on the model and design rules are outlined in order to produce an oil injection potentially able to reduce mechanical work.

Energy saving in sliding vane rotary compressors using pressure swirl oil atomizers

“…A theoretical verification of this important datum has been done following the mathematical representation of the interactions between compressed air and spray. 8 …”

“…8 The spray injection module has been later embedded into a previous model which predicts pressure and temperature inside the cell and evaluates the performances of a SVRC subdividing the physical behavior in a set of processes that interact each other. 3,8 Briefly, it considers:…”

“…The resulting jets do not produce any cooling effect on the air during compression. 8 A technological breakthrough happened using pressure-swirled injectors which demonstrated the capability to cool the air and reduce compression work. The spray injection model predicts:…”

“…6 At the same time, an innovative experimental methodology has been developed to measure the pressure inside the compressor cells, when intake, compression and exhaust occur. The further processing of p-V data allowed the identification of the friction coefficient, 6,7 a better understanding of the cooling action done by the oil during injection, 8 and suggested geometrical re-shaping of the machine for optimization purposes. 7 Furthermore, thanks to this experimental activity, the specific energy consumption for some models of SVRC reached the lowest values in the industrial compressor global market: values around 5.4-5.8 kW=m 3 =min -ISO 1217 conditions (p intake ¼ 1 bar; T intake ¼ 293.15 K) -at 7 bar as pressure delivered.…”

Energy saving in sliding vane rotary compressors

“…At the same time, an innovative experimental methodology has been developed to measure the pressure inside the compressor cells, when intake, compression and exhaust occur. The further processing of p-V data allowed the identification of the friction coefficient (6; 7), a better understanding of the cooling action done by the oil during injection (8), and suggested geometrical re-shaping of the machine for optimization purposes (7). Furthermore, thanks to this experimental activity, the specific energy consumption for some models of SVRC reached the lowest values in the industrial compressor global market: values around 5.4-5.8 kW/m 3 /min -ISO 1217 conditions (p intake = 1 bar; T intake = 293.15 K) -at 7 bar as pressure delivered.…”