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This paper presents a mathematical model of a bottoming Organic Rankine Cycle coupled to a 2 l turbocharged gasoline engine to optimize the cycle from a thermo-economic and sizing point of view. These criteria were optimized with different cycle values. Therefore, a methodology to optimize the ORC coupled to Waste Heat Recovery systems in vehicle applications is presented using a multiobjective optimization algorithm. Multi-objective optimization results show that the optimum solution depend on the importance of each objective to the final solution. Considering thermo-economic criteria as the main objective, greater sizes will be required. Considering sizing criteria as the main objective, higher thermo-economic parameters will be obtained. Therefore, in order to select a single-solution from the Pareto frontier, a multiple attribute decision-making method (TOPSIS) was implemented in order to take into account the preferences of the Decision Maker. Considering the weight factors 0.5 for Specific Investment Cost (SIC), 0.3 for the area of the heat exchangers (Atot) and 0.2 for Volume Coefficient (VC) and the boundaries of this particular application, the result is optimized with values of 0.48 m2 (Atot), 2515 /kW (SIC) and 2.62 MJ/m3 (VC). Moreover, the profitability of the project by means of the Net Present Value and the Payback has been estimated. ; This work is part of a research project called "Evaluation of bottoming cycles in IC engines to recover waste heat energies" funded by a National Project of the Spanish Government with reference TRA2013-46408-R. Authors want to acknowledge the "Apoyo para la investigacion y Desarrollo (PAID)" grant for doctoral studies (FPI S2 2015 1067). Authors acknowledge to ModeFRONTIER (ESTECO) because its support. ; Galindo, J.; Climent, H.; Dolz Ruiz, V.; Royo-Pascual, L. (2016). Multi-objective optimization of a bottoming Organic Rankine Cycle (ORC) of gasoline engine using swash-plate expander. Energy Conversion and Management. 126:1054-1065. ...

This paper deals with the evaluation and analysis of a bottoming ORC cycle coupled to an IC engine by means of conventional and advanced exergy analysis. Using experimental data of an ORC coupled to a 2 l turbocharged engine, both conventional and advanced exergy analysis are carried out. Splitting the exergy in the advanced exergy analysis into unavoidable and avoidable provides a measure of the potential of improving the efficiency of this component. On the other hand, splitting the exergy into endogenous and exogenous provides information between interactions among system components. The result of this study shows that there is a high potential of improvement in this type of cycles. Although, from the conventional analysis, the exergy destruction rate of boiler is greater than the one of the expander, condenser and pump, the advanced exergy analysis suggests that the first priority of improvement should be given to the expander, followed by the pump, the condenser and the boiler. A total amount of 3.75 kW (36.5%) of exergy destruction rate could be lowered, taking account that only the avoidable part of the exergy destruction rate can be reduced. ; This work is part of a research project called "Evaluation of bottoming cycles in IC engines to recover waste heat energies" funded by a National Project of the Spanish Government with reference TRA2013-46408-R. Authors want to acknowledge the "Apoyo para la investigacion y Desarrollo (PAID)" grant for doctoral studies (FPI S2 2015 1067). ; Galindo, J.; Ruiz Rosales, S.; Dolz Ruiz, V.; Royo-Pascual, L. (2016). Advanced exergy analysis for a bottoming organic rankine cycle coupled to an internal combustion engine. Energy Conversion and Management. 126:217-227. https://doi.org/10.1016/j.enconman.2016.07.080 ; S ; 217 ; 227 ; 126

Waste heat recovery (WHR) in exhaust gas flow of automotive engines has proved to be a useful path to increase the overall efficiency of internal combustion engines (ICE). Recovery potentials of up to 7% are shown in several works in the literature. However, most of them are theoretical estimations. Some present results from prototypes fed by steady flows generated in an auxiliary gas tank and not with actual engine exhaust gases. This paper deals with the modeling and experimental validation of an organic Rankine cycle (ORC) with a swash-plate expander integrated in a 2 L turbocharged petrol engine using ethanol as working fluid. A global simulation model of the ORC was developed with a maximum difference of 5%, validated with experimental results. Considering the swash-plate as the main limiting factor, an additional specific submodel was implemented to model the physical phenomena in this element. This model allows simulating the fluid dynamic behavior of the swash-plate expander using a 0D model (Amesim). Differences up to 10.5% between tests and model results were found. ; This work is part of a research project called "Evaluation of bottoming cycles in ICEs to recover waste heat energies" funded by a National Project of the Spanish Government with reference TRA2013-46408-R. The authors thank also to Raul Lujan and Rafael Carrascosa for their contribution in the testing process. Authors want to acknowledge the "Apoyo para la investigacion y Desarrollo (PAID)" grant for doctoral studies (FPI S2 2015 1067). ; Galindo, J.; Dolz Ruiz, V.; Royo-Pascual, L.; Haller, R.; Melis, J. (2016). Modeling and Experimental Validation of a Volumetric Expander Suitable for Waste Heat Recovery from an Automotive Internal Combustion Engine Using an Organic Rankine Cycle with Ethanol. Energies. 9(279):1-18. https://doi.org/10.3390/en9040279 ; S ; 1 ; 18 ; 9 ; 279

This paper deals with the experimental testing of a bottoming Organic Rankine Cycle (ORC) integrate in a 2 l turbocharged gasoline engine using ethanol as working fluid. The main components of the cycle are a boiler, a condenser, a pump and a swash-plate expander. Both steady and transient tests were performed in three engine operating points to understand the behavior and inertia of the system. Pressure-Volume diagram during these transients were presented and analyzed. Operating parameters of the expander, such as expander speed and boiler power, were shifted. The objective of these tests is to understand the inertia of the system and to have a robust control in all the possible transient tests. New European Driving Cycle was tested with and without the expander because it is supposed to represent the typical usage of a car in Europe. It was used to validate the control of the ORC in realistic dynamic conditions of the engine. The importance of each parameter was analyzed by fixing all the parameters, changing each time one specific value. The main result of this paper is that using a slightly simple and robust control based on adaptive PIDs, the two dynamic effects of an ORC could be taken into account, i.e. high inertia effects (boiler and condenser) and low inertia effects (pump and volumetric expander). ; This work is part of a research project called "Evaluation of bottoming cycles in IC engines to recover waste heat energies" funded by a National Project of the Spanish Government with reference TRA2013-46408-R. The authors thank also to Raul Lujan and Rafael Carrascosa for their contribution in the testing process. Authors want to acknowledge the "Apoyo para la investigacion y Desarrollo (PAID)" grant for doctoral studies (FPI S2 2015 1067). ; Torregrosa, AJ.; Galindo, J.; Dolz Ruiz, V.; Royo-Pascual, L.; Haller, R.; Melis, J. (2016). Dynamic tests and adaptive control of a bottoming organic Rankine cycle of IC engine using swash-plate expander. Energy Conversion and Management. 126:168-176. ...

This paper deals with the experimental testing of an Organic Rankine Cycle (ORC) integrate in a 2 liter turbocharged gasoline engine using ethanol as working fluid. The main components of the cycle are a boiler, a condenser, a pump and a swash-plate expander. Five engine operating points have been tested, they correspond to a nominal heat input into the boiler of 5, 12, 20, 25 and 30 kW. With the available bill of material based on prototypes, power balances and cycles efficiencies were estimated, obtaining a maximum improvement in the ICE mechanical power and an expander shaft power of 3.7% and 1.83 kW respectively. A total of 28 steady-state operating points were measured to evaluate performance of the swash-plate expander prototype. Operating parameters of the expander, such as expander speed and expansion ratio, were shifted. The objective of the tests is to master the system and understand physical parameters influence. The importance of each parameter was analyzed by fixing all the parameters, changing each time one specific value. In these sensitivity studies, maximum ideal and real Rankine efficiency value of 19% and 6% were obtained respectively. ; This work is part of a research project called "Evaluation of bottoming cycles in IC engines to recover waste heat energies" funded by a National Project of the Spanish Government with reference TRA2013-46408-R. ; Galindo, J.; Ruiz Rosales, S.; Dolz Ruiz, V.; Royo Pascual, L.; Haller, R.; Nicolas, B.; Glavatskaya, Y. (2015). Experimental and thermodynamic analysis of a bottoming Organic Rankine Cycle (ORC) of gasoline engine using swash-plate expander. Energy Conversion and Management. 103:519-532. https://doi.org/10.1016/j.enconman.2015.06.085 ; S ; 519 ; 532 ; 103