ORC and Advanced Power Cycles

Conventional steam Rankine cycles and open cycle gas turbines play a dominate role in large-scale power production. However there is a large variety of heat sources for which these option do not offer a technically and/or economically viable solution. In these cases the proper selection of the working fluid and of the cycle configuration allow to increase system efficiency, system flexibility and also to reduce the levelised cost of generated energy. Among these solutions the most studied within the GECOS group are the Organic Rankine Cycles (ORC) and the supercritical carbon dioxide cycles (sCO2).

ORC power systems

Organic Rankine Cycles adopt an organic compound (hydrocarbons, halogenated fluids, siloxanes) as working fluid. The possibility to select the main fluid properties allows to obtain large advantages in the design of the components and to always reach high conversion efficiency.

The challenge


The optimisation of an ORC system for a specific application is always a non-trivial task, because of the need to consider simultaneously:

the choice of the best working fluid

the selection and optimization of the best plant layout and components

the effects of fluid properties on expander efficiency

the influence of all these factors on the cost of the plant

Supercritical CO2 power systems

sCO2 cycles can compete with steam Rankine cycles in high temperature applications thanks to the possibility to increase system efficiency and to increase flexibility. The concept is widely studied in literature but this technology is not commercial.

The challenge


The optimisation of these power plant is non-trivial task because of:

The large number (more than 40) of available cycle configurations differing in optimization criteria and strongly affecting the matching with the heat source

The presence of real gas effects at low temperature and high pressure that allow to reduce the compressor consumption but also requires reliable equation of state and a non conventional turbomachinery design

A challenging design of turbine stages and turbine shaft because of the very compact expander dimension and the high specific power

For further information, contact Dr. Marco Astolfi at marco.astolfi@polimi.it or Dr. Marco Binotti at marco.binotti@polimi.it

Related Projects

Recent publications

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2019

Bernardoni, C; Binotti, M; Giostri, A

Techno-economic analysis of closed OTEC cycles for power generation Journal Article

Renewable Energy, 132 , pp. 1018–1033, 2019, ISSN: 0960-1481.

Abstract | Links | BibTeX

2017

Bonalumi, D; Bombarda, P; Invernizzi, C

Potential performance of environmental friendly application of ORC and Flash technology in geothermal power plants Inproceedings

Energy Procedia, pp. 621–628, 2017.

Abstract | Links | BibTeX

Elsido, C; Mian, A; Martelli, E

A systematic methodology for the techno-economic optimization of Organic Rankine Cycles Inproceedings

Energy Procedia, pp. 26–33, 2017.

Abstract | Links | BibTeX

Astolfi, M; Martelli, E; Pierobon, L

Thermodynamic and technoeconomic optimization of Organic Rankine Cycle systems Incollection

Macchi, Ennio; Astolfi, Marco (Ed.): Organic Rankine Cycle (ORC) Power Systems, pp. 173–249, Elsevier, 2017.

Abstract | Links | BibTeX

Macchi, E; Astolfi, M

Axial flow turbines for Organic Rankine Cycle applications Incollection

Macchi, Ennio; Astolfi, Marco (Ed.): Organic Rankine Cycle (ORC) Power Systems: Technologies and Applications, pp. 299–319, Woodhead Publishing, 2017.

Abstract | Links | BibTeX

Macchi, E; Astolfi, M

Organic Rankine Cycle (ORC) Power Systems: Technologies and Applications Book

Woodhead Publishing, 2017, ISBN: 978-0-08-100510-1.

Abstract | Links | BibTeX

Giuffrida, A; Pezzuto, D

Assessing the performance of a scroll expander with a selection of fluids suitable for low-temperature applications Inproceedings

Energy Procedia, pp. 493–500, 2017.

Abstract | Links | BibTeX

Iora, P; Di Marcoberardino, G; Invernizzi, C M; Manzolini, G; Belotti, P; Bini, R

Dynamic analysis of off-grid systems with ORC plants adopting various solution for the thermal storage Inproceedings

Energy Procedia, pp. 216–223, 2017.

Abstract | Links | BibTeX

Scaccabarozzi, R; Tavano, M; Invernizzi, C M; Martelli, E

Thermodynamic Optimization of heat recovery ORCs for heavy duty Internal Combustion Engine: Pure fluids vs. zeotropic mixtures Inproceedings

Energy Procedia, pp. 168–175, 2017.

Abstract | Links | BibTeX

Murgia, S; Valenti, G; Colletta, D; Costanzo, I; Contaldi, G

Experimental investigation into an ORC-based low-grade energy recovery system equipped with sliding-vane expander using hot oil from an air compressor as thermal source Inproceedings

Energy Procedia, pp. 339–346, 2017.

Abstract | Links | BibTeX

43 entries « 1 of 5 »