Share

Modelling of multiphase twin screw machines.

Number: pap. F14

Author(s) : KOVACEVIC A., RANE S.

Summary

Twin screw compressors used in refrigeration, gas and air compression represent approximately 80% of the millions of industrial positive displacement compressors produced globally each year. More than 95% of these are oil injected. Oil injected twin screw compressor is just one type of multiphase screw machines. Other include twin screw expanders, multiphase pumps and motors. Multiphase twin screw machines are traditionally analysed and designed by use of chamber thermodynamic models. However for further improvement of efficiency and reliability it is necessary to use more advanced modelling techniques such as 3D Computational Fluid Dynamics (CFD). In order to obtain fast and accurate solution of multiphase screw machines using CFD, it is important that a numerical grid of the highest quality is generated quickly and reliably. For that purpose, a deforming grid of a twin screw machine is generated using algebraic transfinite interpolation upon which an elliptic partial differential equations (PDE) of the Poisson’s form are solved numerically to produce smooth final computational mesh. This is built in the grid generation software SCORGTM which allows fast mesh generation and the quality of numerical mesh for use with variety of commercial CFD solvers. A test oil injected twin screw compressor with rotor configuration 4/5 and 127 mm main rotor diameter was measured in the compressor rig of the Centre for Compressor Technology at City, University of London. The performance prediction obtained using SCORG mesh and commercial CFD solver showed a close match with measured mass flow rates and indicated power. The model provided an exceptional visualization of the interaction of gas and oil inside the compression chamber. The mixing of the phases, distribution of oil, heat transfer between gas and oil and also effects on sealing due to high oil concentration in leakage gaps were well captured.

Available documents

Format PDF

Pages: 12

Available

  • Public price

    20 €

  • Member price*

    15 €

* Best rate depending on membership category (see the detailed benefits of individual and corporate memberships).

Details

  • Original title: Modelling of multiphase twin screw machines.
  • Record ID : 30022106
  • Languages: English
  • Source: 8th international conference on compressors and refrigeration, 2017.
  • Publication date: 2017/07/20

Links


See other articles from the proceedings (97)
See the conference proceedings

Indexing