0
Research Papers

Introduction of Circumferentially Nonuniform Variable Guide Vanes in the Inlet Plenum of a Centrifugal Compressor for Minimum Losses and Flow Distortion

[+] Author and Article Information
Ismail Sezal

GE Global Research,
Munich 85748, Germany
e-mail: sezali@ge.com

Nan Chen, Wolfgang Erhard

Institute for Flight Propulsion,
Technische Universität München,
Garching 85748, Germany

Christian Aalburg

GE Global Research,
Munich 85748, Germany

Rajesh Kumar V. Gadamsetty

GE Global Research,
Bangalore 560066, India

Alberto Scotti Del Greco, Libero Tapinassi

GE Oil & Gas,
Florence 50127, Italy

Matthias Lang

Porsche AG,
Weissach 71287, Germany

1Corressponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received January 22, 2016; final manuscript received February 10, 2016; published online April 12, 2016. Editor: Kenneth C. Hall.

J. Turbomach 138(9), 091008 (Apr 12, 2016) (10 pages) Paper No: TURBO-16-1018; doi: 10.1115/1.4032884 History: Received January 22, 2016; Revised February 10, 2016

In the oil and gas industry, large variations in flow rates are often encountered, which require compression trains with a wide operating range. If the stable operating range at constant speed is insufficient, variable speed drivers can be used to meet the requirements. Alternatively, variable inlet guide vanes (IGVs) can be introduced into the inlet plenum to provide pre- or counterswirl to the first-stage impeller, possibly eliminating the need for variable speed. This paper presents the development and validation of circumferentially nonuniform IGVs that were specifically designed to provide maximum angle variation at minimum losses and flow distortion for the downstream impeller. This includes the comparison of three concepts: a baseline design based on circumferentially uniform and symmetric profiles, two circumferentially nonuniform concepts based on uniquely cambered airfoils at each circumferential position, and a multi-airfoil configuration consisting of a uniquely cambered fixed part and a movable part. The idea behind the circumferentially nonuniform designs was to take into account nonsymmetric flow features inside the plenum and a bias toward large preswirl angles rather than counter-swirl during practical operation. The designs were carried out by computational fluid dynamics (CFD) and first tested in a steady, full-annulus cascade in order to quantify pressure losses and flow quality at the inlet to the impeller at different IGV setting angles (ranging from −20 deg to +60 deg) and flow rates. Subsequently, the designs were mounted in front of a typical oil and gas impeller on a high-speed rotating rig in order to determine the impact of flow distortion on the impeller performance. The results show that pressure losses in the inlet plenum could be reduced by up to 40% with the circumferentially nonuniform designs over the symmetric baseline configuration. Furthermore, a significant reduction in circumferential distortion could be achieved with the circumferentially nonuniform designs. The resulting improvement in impeller performance contributed approximately 40% to the overall efficiency gains for inlet plenum and impeller combined.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Del Greco, A. S. , and Tapinassi, L. , 2014, “ On the Combined Effect on Operating Range of Adjustable Inlet Guide Vanes and Variable Speed in Process Multistage Centrifugal Compressors,” ASME J. Eng. Gas Turbines Power, 136(8), p. 082601. [CrossRef]
Lüdtke, K. H. , 2004, Process Centrifugal Processors: Basics, Function, Operation, Design, Application, Springer, Berlin.
Schmieder, M. , 2013, “ Experimental Investigations on the Impact of Adjustable Guide Vanes on Inflow Conditions of a Centrifugal Compressor,” Master thesis, Institute for Flight Propulsion, Technische Universität München, Garching, Germany.
Lang, S. , Erhard, W. , Kau, H. P. , Pannekeet, R. , Aalburg, C. , and du Cauze de Nazelle, R. , 2014, “ Application of Flow Control on a Radial Compressor for Operating Range Extension,” 15th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Honolulu, HI, Feb. 24–28.
Mohseni, A. , Goldhahn, E. , Van den Braembussche, R. A. , and Seume, J. R. , 2012, “ Novel IGV Designs for Centrifugal Compressors and Their Interaction With the Impeller,” ASME J. Turbomach., 134(2), p. 021006. [CrossRef]
Saravanamutto, H. I. H. , Rogers, G. F. C. , and Cohen, H. , 2001, Gas Turbine Theory, 5th ed., Pearson Education, Harlow, UK.
Aalburg, C. , Sezal, I. , Haigermoser, C. , Simpson, A. , Michelassi, V. , and Sassanelli, G. , 2011, “ Annular Cascade for Radial Compressor Development,” ASME Paper No. GT2011-46834.
Harada, H. , 1985, “ Performance Characteristics of Shrouded and Unshrouded Impellers of a Centrifugal Compressor,” ASME J. Eng. Gas Turbines Power, 107(2), pp. 528–533. [CrossRef]
Steinke, R. J. , and Crouse, J. E. , 1967, “ Preliminary Analysis of the Effectiveness of Variable-Geometry Guide Vanes to Control Rotor-Inlet Flow Conditions,” NASA, Washington, DC, Technical Note TN D-3823.
Whitfield, A. , 2000, “ Review of Variable Geometry Techniques Applied to Enhance the Performance of Centrifugal Compressors,” International Compressor Engineering Conference, Purdue University, Paper No. 1368.

Figures

Grahic Jump Location
Fig. 1

Impeller velocity triangles for large volume flow without and with counterswirl (top left and right, respectively) and for small volume flow without and with preswirl (bottom left and right, respectively), from Ref. [3]

Grahic Jump Location
Fig. 2

Inlet plenum with baseline (symmetric) IGVs (left) and meridional view of the computational domain at the symmetry axis of the plenum with impeller flow path (right)

Grahic Jump Location
Fig. 3

Contours of static entropy of the plenum with baseline (symmetric) IGVs at 0 deg (left) and 60 deg (right) IGV setting angle

Grahic Jump Location
Fig. 4

Sketch of IGV inlet plenum

Grahic Jump Location
Fig. 5

Plenum loss coefficient normalized by the baseline prediction for 0 deg IGV angle setting as a function of delivered yaw angle at section 10. Predictions, steady, and rotating test results for all the three IGV designs are shown.

Grahic Jump Location
Fig. 6

Conceptual sketches of all the three different IGV airfoil types used in the analysis

Grahic Jump Location
Fig. 7

Schematic of steady test facility, from Ref. [7]

Grahic Jump Location
Fig. 8

Instrumentation of inflow section 0

Grahic Jump Location
Fig. 9

Instrumentation of section 10 with rakes mounted on a rotating hub

Grahic Jump Location
Fig. 10

Delivered yaw angle at section 10 as a function of IGV angle setting angle. Predictions, steady, and rotating test results for all the three IGV designs are shown.

Grahic Jump Location
Fig. 11

Steady test results versus predictions of spanwise-averaged axial Mach number (top) and yaw angle (bottom) at section 10 for all the three IGV designs at 0 deg IGV setting angle

Grahic Jump Location
Fig. 12

Sketch of the TUM-LFA centrifugal compressor test rig

Grahic Jump Location
Fig. 13

Schematic cross section of the compressor stage with IGV plenum (inlet venturi and piping not included)

Grahic Jump Location
Fig. 14

Contours of axial Mach number at section 10, measured during the rotating test. The nominal points at each IGV setting angle (−20 deg to 60 deg from top to bottom) and for each IGV type (A–C from left to right) are shown.

Grahic Jump Location
Fig. 15

Contours of yaw angle at section 10, measured during the rotating test. The nominal points at each IGV setting angle (−20 deg to 60 deg from top to bottom) and for each IGV type (A–C from left to right) are shown.

Grahic Jump Location
Fig. 16

Impeller work coefficient (sections 10–60) as a function of normalized flow coefficient. The measurements of the three designs across different IGV setting angles ranging from −20 deg to 60 deg are shown.

Grahic Jump Location
Fig. 17

Impeller polytropic efficiency (sections 10–20) as a function of normalized flow coefficient. The measurements of the three designs across different IGV setting angles ranging from −20 deg to 60 deg are shown.

Grahic Jump Location
Fig. 18

Combined plenum plus stage polytropic efficiency (sections 0–60) as a function of normalized flow coefficient. The measurements of the three designs across different IGV setting angles ranging from −20 deg to 60 deg are shown.

Grahic Jump Location
Fig. 19

Combined plenum plus stage head coefficient (sections 0–60) as a function of normalized flow coefficient. The measurements of the three designs across different IGV setting angles ranging from −20 deg to 60 deg are shown.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In