[home] [Personal Program] [Help]

---

Session: Poster Session and Sponsors Exhibition
Session starts: Thursday 22 September, 14:00

---

Stefano Clemente (University of Trieste - Italy)
Diego Micheli (University of Trieste - Italy)
Mauro Reini (University of Trieste - Italy)
Rodolfo Taccani (University of Trieste - Italy)

Abstract:
The paper presents the simulation model of a small-scale Organic Rankine Cycle (ORC), conveniently usable to recover electrical power from low-temperature heat sources, such as the exhaust gases of internal combustion engines, solar panels or biomass boilers. Aim of the paper is to achieve an overall knowledge of the expected performance of the experimental test bench currently under development at the Energy Systems Laboratory (EneSysLab) of the Department of Mechanical Engineering and Naval Architecture of the University of Trieste. The global model has been implemented with Aspen® simulation software, taking into account the real behavior of the system components in design and off-design conditions. All the heat exchangers have been modeled referring to the geometrical data provided by the manufacturer, and have been validated by comparing the simulated performances with the declared ones. Detailed one-dimensional models have been developed to predict the behavior of the expander, since it represents the most critical component of the cycle in terms of efficiency: MatLab® codes have been implemented for both a scroll expander [1-3] and an alternative (piston-type) machine [4, 5]. Several working curves (at various operating conditions and with reference to R245fa and isopentane as working fluids) have been obtained and used in the global model. In such a way, main dissipative phenomena in all components - like heat transfers toward ambient, pressure drops, expander leakages, etc. - can properly be taken into account in different applications and operating conditions, and the relative weight of each dissipative phenomenon and of each heat transfer irreversibility, affecting the cogenerator behavior, can be separately evaluated, highlighting possible design improvements for some components and for the whole system. REFERENCES [1] M. Kane, D. Larrain, D. Favrat, Y. Allani, “Small hybrid solar power system”, Energy, Vol. 28 (14), pp. 1427-1443 (2003). [2] V. Lemort, S. Quoilin, C. Cuevas, J. Lebrun, “Testing and Modeling of a Scroll Ex-pander Integrated into an Organic Rankine Cycle”, Appl. Therm. Eng., Vol. 29, pp. 3094-3102, (2009). [3] S. Clemente, D. Micheli, M. Reini, R. Taccani, “Numerical Model and Performance Analysis of a Scroll Machine for ORC Applications”, Proceedings of ECOS2010, June 14-17, Lausanne (CH), (2010). [4] M. Badami and M. Mura, “Preliminary design and controlling strategies of a small-scale wood waste Rankine Cycle (RC) with a reciprocating steam engine (SE)”, Energy, 34, pp. 1315-1324, (2009). [5] S. Clemente, D. Micheli, M. Reini, R. Taccani, “Performance analysis and modelling of different volumetric expanders for small-scale Organic Rankine Cycles” Proceedings of ESFuelCell2011, August 7-10, Washington DC ( USA) (2011).