Numerical Analysis of the Structural Parameters on the Performance of Oil-Injected Rotary Vane Compressors

Abstract

The performance improvement potential with the optimisation of vane geometry and port timing angle in oil-injected Rotary Vane Compressors (RVCs) is not yet fully understood. Commonly, studies have used single-phase CFD models without consideration of lubricating oil. However, the presented analysis uses a more complex oil–gas two-phase CFD model. A fully analytical grid generation method was used for discretisation of the rotor domain, and the numerical method was validated against the experimental results. Coupled with the analysis of the flow field, the effects of five vane parameters and four configurations of port timing angles on the compressor performance were studied. The results show that the baseline case of the RVC achieved the volumetric and adiabatic efficiencies of 95.4% and 62.3%, respectively, while the specific power was 9.47 kW/(m3·min−1), which is consistent with typical industrial RVCs. The RVC as a high-efficiency compressor highly relies on the vane tip clearance size. The baseline parameters of the vane geometry and the port timing angles are relatively reasonable, and further optimisation of vane thickness, vane tip radius, vane eccentric angle, vane tip eccentric angle, intake port closing angle and exhaust port closing angle contributes to 1.7% decrease in the specific power. Overall, the structural parameter optimisation carried out in this paper, combined with the operational parameter optimisation conducted in previous studies, leads to a power reduction of 5.6%.