This paper evaluates the performance of an organic Rankine cycle (ORC) based micro- combined heat and power (CHP) unit using a scroll expander. The considered system consists of a fuel boiler coupled with an ORC engine. As a preliminary step, the results of an experimental campaign and the modeling of a hermetic, lubricated scroll compressor used as an expander are presented. Then, a fluid comparison based on several criteria is conducted, leading to the selection of R245fa as working fluid for the ORC. A simulation model is then built to evaluate the performance of the system. The model associates an ORC model and a boiler model, both experimentally validated. This model is used to optimize and size the system. The optimization is performed considering two degrees of freedom: the evaporating temperature and the heat transfer fluid (HTF) mass flow rate. Seasonal simulation is finally performed with a bin method according to the standard PrEN14825 for an average European climate and for four heat emitter heating curves. Simulation results show that the electrical efficiency of the system varies from 6.35% for hot water at 65 °C (high temperature application) to 8.6% for a hot water temperature of 22 °C (low temperature application). Over one entire year, the system exhibits an overall electrical efficiency of about 8% and an overall thermal efficiency around 87% without significant difference between the four heat emitter heating curves. Finally, some improvements of the scroll expander are evaluated. It is shown that by increasing the maximum inlet temperature (limited to 140 °C due to technical reasons) and using two scroll expanders in series, the overall electrical efficiency reaches 12.5%.

References

References
1.
De Paepe
,
M.
, and
Mertens
,
D.
,
2007
, “
Combined Heat and Power in a Liberalized Energy Market
,”
J. Energy Convers. Manage.
,
48
, pp.
2542
2555
.10.1016/j.enconman.2007.03.019
2.
Siemers
,
W.
,
2007
, “
Technical and Economic Comparison of Different Technologies for Micro-CHP
,”
internal research paper, CUTEC-Institut, Clausthal-Zellerfeld, Germany
.
3.
Liu
,
H.
,
Qiu
,
G.
,
Shao
,
Y.
,
Daminabo
,
F.
, and
Riffat
,
S. B.
,
2010
, “
Preliminary Experimental Investigations of a Biogas-Fired Micro-Scale CHP With Organic Rankine Cycle
,”
Int. J. Low-Carb. Tech.
,
5
, pp.
81
87
.10.1093/ijlct/ctq005
4.
Lombradi
,
K.
,
Ugursal
,
V. I.
, and
Beausoleil-Morrison
,
I.
,
2008
, “
Performance and Emissions Testing of 1 kWe Stirling Engine
,”
Proc. Micro-Cogeneration
,
Ottawa, Canada
, April 29–May 1.
5.
Andlauer
,
B.
,
Stabat
,
P.
,
Marchio
,
D.
, and
Flament
,
B.
,
2010
, “
Multi-Objective Optimization Procedures for Sizing Operating Building-Integrated Micro-Cogeneration Systems
,”
Proc. 8th International Conference on System in Buildings
,
Liège
, Belgium, December 13–15.
6.
Simader
,
G.
,
Krawinkler
,
R.
, and
Trnka
,
G.
,
2006
, “
Micro CHP Systems: State-of-the-Art
,” Deliverable 8 (D8) of Green Lodges Project (EIE/04/252/S07.38608),
Austrian Energy Agency
, Vienna, Austria, March.
7.
Lemort
,
V.
,
Quoilin
,
S.
, and
Declaye
,
S.
,
2012
, “
Experimental Characterization of a Hermetic Scroll Expander for Use in a Micro-Scale Rankine Cycle
,”
J. Power Energ.
,
226
, pp.
126
136
.10.1177/0957650911413840
8.
Lemort
,
V.
,
Quoilin
,
S.
,
Cuevas
,
C.
, and
Lebrun
,
J.
,
2009
, “
Testing and Modeling a Scroll Expander Integrated Into an Organic Rankine Cycle
,”
J. Appl. Therm. Eng.
,
29
, pp.
3094
3102
.10.1016/j.applthermaleng.2009.04.013
9.
Zanelli
,
R.
, and
Favrat
,
D.
,
1994
, “
Experimental Investigation of a Hermetic Scroll Expander-Generator
,”
12th International Compressor Engineering Conference, Purdue University, West Lafayette, IN, July 12–19
, pp.
459
464
.
10.
Quoilin
,
S.
,
Declaye
,
S.
, and
Lemort
,
V.
,
2010
, “
Expansion Machine and Fluid Selection for the Organic Rankine Cycle
,”
Proc. 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics
,
Antalya
, Turkey, July 19–21.
11.
Quoilin
,
S.
,
Lemort
,
V.
, and
Lebrun
,
J.
,
2010
, “
Experimental Study and Modeling of an Organic Rankine Cycle Using Scroll Expander
,”
J. Appl. Energ.
,
87
, pp.
1260
1268
.10.1016/j.apenergy.2009.06.026
12.
Aoun
,
B.
,
2008
, “
Micro Cogénération pour les batiments residentiels fonctionnant avec des energie renouvelables
,” Ph.D. thesis,
Ecole des Mines de Paris
, Paris.
13.
Lebrun
,
J.
,
Bourdouxhe
,
J. P.
, and
Grodent
,
M.
,
1999
, “
HVAC1KIT—A Toolkit for Primary HVAC System Energy Calculation
,” prepared for ASHRAE TC 4.7 Energy Calculation,
Laboratory of Thermodynamics, University of Liège, Liège, Belgium
.
14.
European Parliament and Council
,
2007
, “
Commission Decision of 21 December 2006 Establishing Harmonised Efficiency Reference Values for Separate Production of Electricity and Heat in Application of Directive 2004/8/EC of the European Parliament and of the Council
,” Document number C(2006) 6817), OJ L
32
, 6.2.2007, pp.
183
188
.
15.
McMahan
,
A.
,
2006
, “
Design & Optimization of Organic Rankine Cycle Solar-Thermal Powerplants
,” Ph.D. thesis,
University of Wisconsin-Madison
,
Madison, WI
16.
Quoilin
,
S.
,
2011
, “
Sustainable Energy Conversion Through the Use of Organic Ranking Cycles for Waste Heat Recovery and Sola Applications
,” Ph.D. thesis,
University of Liège
,
Liège, Belgium
.
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