Research Papers: Gas Turbines: Turbomachinery

The Role of Dense Gas Dynamics on Organic Rankine Cycle Turbine Performance

[+] Author and Article Information
Andrew P. S. Wheeler

Faculty of Engineering and the Environment,
University of Southampton,
Southampton, UK
e-mail: a.wheeler@soton.ac.uk

Jonathan Ong

GE Global Research,
Freisinger Landstr., 50 Garching n.,
Munich 85748, Germany

Contributed by the Turbomachinery Committee of ASME for publication in the Journal of Engineering for Gas Turbines and Power. Manuscript received July 1, 2013; final manuscript received July 2, 2013; published online September 6, 2013. Editor: David Wisler.

J. Eng. Gas Turbines Power 135(10), 102603 (Sep 06, 2013) (9 pages) Paper No: GTP-13-1214; doi: 10.1115/1.4024963 History: Received July 01, 2013; Revised July 02, 2013

In this paper, we investigate the real gas flows which occur within organic Rankine cycle (ORC) turbines. A new method for the design of nozzles operating with dense gases is discussed, and applied to the case of a high pressure ratio turbine vane. A Navier–Stokes method, which uses equations of states for a variety of working fluids typical of ORC turbines, is then applied to the turbine vanes to determine the vane performance. The results suggest that the choice of working fluid has a significant influence on the turbine efficiency.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

Typical mesh for the nozzle calculations

Grahic Jump Location
Fig. 2

Block stucture and typical mesh for the vane calculations

Grahic Jump Location
Fig. 3

Pressure-density plots along isentropes at a range of stagnation pressures for (a) Pentane and (b) R245fa (To/Tc = 1.05, Data obtained from NIST [24-26])

Grahic Jump Location
Fig. 4

Variation of Prandtl–Meyer function with Mach number for several values of k

Grahic Jump Location
Fig. 5

Variation of Prandtl–Meyer function with Mach number determined from REFPROP data for pentane at stagnation conditions po/pc = 0.9,To/Tc = 1.05, and using Eq. (7)

Grahic Jump Location
Fig. 6

Nozzle shapes as determined from the MOC outlined in Sec. 3 (Mexit = 2.0,Ro/O = 2.5)

Grahic Jump Location
Fig. 7

Schematic of the nozzle design

Grahic Jump Location
Fig. 8

RANS versus MOC Mach number for nozzle with pentane working fluid, poin = 20 bar, Toin = 450 K, pexit = 2 bar: (a) Nozzle designed using a constant value for k = 0.92 and (b) nozzle designed using the correction shown in Eq. (10)

Grahic Jump Location
Fig. 9

Predicted nozzle flow-field from RANS calculations, pentane working fluid, poin = 20 bar, Toin = 450 K, and pexit = 2 bar

Grahic Jump Location
Fig. 10

Schematic showing the vane geometry

Grahic Jump Location
Fig. 12

Mach contours for vanes operating with Pentane

Grahic Jump Location
Fig. 13

Predicted Mach contours for vanes operating with R245fa

Grahic Jump Location
Fig. 14

Predicted vane loss coefficients (hexit-hs,exit)¯/(ho,in-hs,exit)¯ at 20% radial chord downstream of the vane trailing-edge. (Overbar indicates mass-weighted average.)

Grahic Jump Location
Fig. 15

Predicted wake profiles at 20% radial chord downstream of the vane trailing-edge




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