The application of organic Rankine cycles (ORCs) for small scale power generation is inhibited by a lack of suitable expansion devices. Thermodynamic and mechanistic considerations suggest that scroll machines are advantageous in kilowatt-scale ORC equipment, however, a method of independently selecting a geometric design optimized for high-volume-ratio ORC scroll expanders is needed. The generalized 8-dimensional planar curve framework (Gravesen and Henriksen, 2001, “The Geometry of the Scroll Compressor,” Soc. Ind. Appl. Math., 43, pp. 113–126), previously developed for scroll compressors, is applied to the expansion scroll and its useful domain limits are defined. The set of workable scroll geometries is: (1) established using a generate-and-test algorithm with inclusion based on theoretical viability and engineering criteria, and (2) the corresponding parameter space is related to thermodynamically relevant metrics through an analytic ranking quantity fc (“compactness factor”) equal to the volume ratio divided by the normalized scroll diameter. This method for selecting optimal scroll geometry is described and demonstrated using a 3 kWe ORC specification as an example. Workable scroll geometry identification is achieved at a rate greater than 3 s−1 with standard desktop computing, whereas the originally undefined 8-D parameter space yields an arbitrarily low success rate for determining valid scroll mating pairs. For the test case, a maximum isentropic expansion efficiency of 85% is found by examining a subset of candidates selected the for compactness factor (volume expansion ratio per diameter), which is shown to correlate with the modeled isentropic efficiency (R2 = 0.88). The rapid computationally efficient generation and selection of complex validated scroll geometries ranked by physically meaningful properties is demonstrated. This procedure represents an essential preliminary qualification for intensive modeling and prototyping efforts necessary to generate new high performance scroll expander designs for kilowatt scale ORC systems.

References

1.
Lemort
,
V.
,
Quoilin
,
S.
,
Cuevas
,
C.
, and
Lebrun
,
J.
,
2009
, “
Testing and Modeling a Scroll Expander Integrated Into an Organic Rankine Cycle
,”
Appl. Therm. Eng.
,
29
(
14–15
), pp.
3094
3102
.10.1016/j.applthermaleng.2009.04.013
2.
Wang
,
H.
,
Peterson
,
R. B.
, and
Herron
,
T.
,
2009
, “
Experimental Performance of a Compliant Scroll Expander for an Organic Rankine Cycle
,”
Proc. Inst. Mech. Eng., Part A
,
223
(
7
), pp.
863
872
.10.1243/09576509JPE741
3.
Harada
,
K.
,
2010
, “
Development of a Small Scale Scroll Expander
,” M.S. thesis, Oregon State University, Corvallis, OR.
4.
Xiaojun
,
G.
,
Liansheng
,
L.
,
Yuanyang
,
Z.
, and
Pengcheng
,
S.
,
2004
, “
Research on a Scroll Expander Used for Recovering Work in a Fuel Cell
,”
Int. J. of Thermodyn.
,
7
(
1
), pp.
1
8
.
5.
Nagata
,
H.
,
Kakuda
,
M.
,
Sekiya
,
S.
,
Shimoji
,
M.
, and
Koda
,
T.
,
2010
, “
Development of a Scroll Expander for the CO2 Refrigeration Cycle
,”
International Symposium on Next-Generation Air Conditioning and Refrigeration Technology
,
Tokyo
, February 17–19.
6.
Kim
,
H. J.
,
Ahn
,
J. M.
,
Park
,
I.
, and
Rha
,
P. C.
,
2007
, “
Scroll Expander for Power Generation From a Low-Grade Steam Source
,”
Proc. Inst. Mech. Eng., Part A
,
221
(
5
), pp.
705
711
.10.1243/09576509JPE392
7.
Wang
,
B.
,
Li
,
X.
, and
Shi
,
W.
,
2005
, “
A General Geometrical Model of Scroll Compressors Based on Discretional Initial Angles of Involute
,”
Int. J. Refrig.
,
28
, pp.
958
966
.10.1016/j.ijrefrig.2005.01.015
8.
Gravesen
,
J.
, and
Henriksen
,
C.
,
2001
, “
The Geometry of the Scroll Compressor
,”
Soc. Ind. Appl. Math.
,
43
, pp.
113
126
. 10.1137/S0036144599362121
9.
Blunier
,
B.
,
Cirrincione
,
G.
,
Herve
,
Y.
, and
Miraoui
,
A.
,
2006
, “
Novel Geometrical Model of Scroll Compressors for the Analytical Description of the Chamber Volumes
,”
International Compressor Engineering Conference
, Purdue, West Lafayette, IN, July 17–20, Paper No. 1745.
10.
Lemort
,
V.
, and
Quoilin
,
S.
,
2009
, “
Designing Scroll Expanders for Use in Heat Recovery Rankine Cycles
,”
Proceedings of the IMechE International Conference of Compressors and Their Systems (IMechE 2009), London, September 7–9
, pp.
3
12
.
11.
Chen
,
Y.
,
Halm
,
N. P.
,
Groll
,
E. A.
, and
Braun
,
J. E.
,
2002
, “
Mathematical Modeling of Scroll Compressor—Part I: Compression Process Modeling
,”
Int. J. Refrig.
,
25
, pp.
731
750
.10.1016/S0140-7007(01)00071-8
12.
Dechesne
,
B.
,
2012
, “
Designing a Scroll Expander for a Micro-Solar Power Plant
” S.M. thesis, Thermodynamics Laboratory, Aerospace and Mechanical Engineering Department, University of Liege, Liege, Belgium.
13.
Dechesne
,
B.
,
Orosz
,
M.
,
Legros
,
A.
, and
Hemond
,
H.
,
2012
, “
Development of a Scroll Expander for Micro-CSP With Organic Rankine Cycle
,”
Proceedings of the Solar Power and Chemical Energy Systems (SolarPACES) Conference
,
Marrakesh, Morocco
, September 11–14, Poster No. I-03.
14.
Bell
,
I.
,
Groll
,
E. A.
,
Braun
,
J. E.
, and
King
,
G.
,
2010
, “
Update on Scroll Compressor Chamber Geometry
,”
International Compressor Engineering Conference
, Purdue, West Lafayette, IN, July 12–15, Paper No. 2033.
15.
Lemort
,
V.
,
Declaye
,
S.
, and
Quoilin
,
S.
,
2012
, “
Experimental Characterization of a Hermetic Scroll Expander for Use in a Micro-Scale Rankine Cycle
,”
Proc. Insti. Mech. Eng., Part A
,
226
(1)
, pp.
126
136
.10.1177/0957650911413840
16.
Orosz
,
M.
,
2012
, “
ThermoSolar and Photovoltaic Hybridization for Small Scale Distributed Generation: Applications for Powering Rural Health
,” Ph.D. thesis, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA.
17.
Quoilin
,
S.
,
Declaye
,
S.
, and
Lemort
,
V.
,
2010
, “
Expansion Machine and Fluid Selection for the Organic Rankine Cycle
,”
Hefat 2010—7th International Conference on Heat Transfer
,
Fluid Mechanics and Thermodynamics
, Antalya, Turkey, July 19–21, http://hdl.handle.net/2268/62997
18.
Cengel
,
Y. A.
,
2007
,
Heat and Mass Transfer: A Practical Approach
,
McGraw-Hill
,
New York
.
19.
Hiwata
,
A.
,
Ikeda
,
A.
,
Morimoto
,
T.
,
Kosuda
,
O.
, and
Matsui
,
M.
,
2008
, “
Axial and Radial Force Control for CO2 Scroll Expander
,”
International Compressor Engineering Conference
, Purdue, West Lafayette, IN, July 14–17, Paper No. 1849.
You do not currently have access to this content.