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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2017

Astolfi, M; La Diega, L N; Romano, M C; Merlo, U; Filippini, S; Macchi, E

Application of the Novel "emeritus" Air Cooled Condenser in Geothermal ORC Inproceedings

Energy Procedia, pp. 479–486, 2017.

Abstract | Links | BibTeX

Gómez Aláez, S L; Brizzi, V; Alfani, D; Silva, P; Giostri, A; Astolfi, M

Off-design study of a waste heat recovery ORC module in gas pipelines recompression station Inproceedings

Energy Procedia, pp. 567–574, 2017.

Abstract | Links | BibTeX

Astolfi, M; Fantolini, A M; Valenti, G; De Rinaldis, S; Inglese, L D; Macchi, E

Cryogenic ORC to Enhance the Efficiency of LNG Regasification Terminals Inproceedings

Energy Procedia, pp. 42–49, 2017.

Abstract | Links | BibTeX

Macchi, E

Theoretical basis of the Organic Rankine Cycle Incollection

Macchi, Ennio; Astolfi, Marco (Ed.): Organic Rankine Cycle (ORC) Power Systems: Technologies and Applications, pp. 3–24, Woodhead Publishing, 2017.

Abstract | Links | BibTeX

Binotti, M; Astolfi, M; Campanari, S; Manzolini, G; Silva, P

Preliminary assessment of sCO2 cycles for power generation in CSP solar tower plants Journal Article

Applied Energy, 204 , pp. 1007–1017, 2017.

Abstract | Links | BibTeX

Binotti, M; Astolfi, M; Campanari, S; Manzolini, G; Silva, P

Preliminary Assessment of sCO2 Power Cycles for Application to CSP Solar Tower Plants Inproceedings

Energy Procedia, pp. 1116–1122, 2017.

Abstract | Links | BibTeX

Invernizzi, C M; Iora, P; Manzolini, G; Lasala, S

Thermal stability of n-pentane, cyclo-pentane and toluene as working fluids in organic Rankine engines Journal Article

Applied Thermal Engineering, 121 , pp. 172–179, 2017.

Abstract | Links | BibTeX

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

An intracooling system for a novel two-stage sliding-vane air compressor Inproceedings

IOP Conference Series: Materials Science and Engineering, 2017.

Abstract | Links | BibTeX

2016

Invernizzi, C M; Iora, P; Preßinger, M; Manzolini, G

HFOs as substitute for R-134a as working fluids in ORC power plants: A thermodynamic assessment and thermal stability analysis Journal Article

Applied Thermal Engineering, 103 , pp. 790–797, 2016.

Abstract | Links | BibTeX

2015

Gómez Aláez, S L; Bombarda, P; Invernizzi, C M; Iora, P; Silva, P

Evaluation of ORC modules performance adopting commercial plastic heat exchangers Journal Article

Applied Energy, 154 , pp. 882–890, 2015.

Abstract | Links | BibTeX

43 entries « 2 of 5 »