Introduce your company logo here THERMOECONOMIC OPTIMIZATION OF

Introduce your company logo here THERMO-ECONOMIC OPTIMIZATION OF ORAGNIC RANKINE CYCLE SYSTEMS FOR WASTE HEAT RECOVERY FROM EXHAUST AND RECIRCULATED GASES OF HEAVY DUTY TRUCKS L. Guillaumea, A. Legrosa, V. Lemorta a. Department of A&M, Thermodynamics laboratory, University of Liege, Belgium 3 rd Engine ORC Consortium Workshop September 14 -16, Belfast, Northern Ireland

Introduction • ORC waste heat recovery • Fuel consumption and CO 2 emissions • Design: • Essential part of the design process • Library of steady-state models • Numerous steady-state models of different candidate ORCs • Design in three steps • Selection of the design conditions • Design (Optimization) • Evaluation of the off design performance • Thermodynamic vs thermo-economic optimization • Cost relations for all components 3 rd EORC workshop, Belfast, 2016

Introduction Context 3 rd EORC workshop, Belfast, 2016

Heat sources and heat sink Heat Source Temperature Capacity flow rate Exhaust gases mid to high EGR gases high low Charge Air low to mid high Coolant low high Oil low 3 rd EORC workshop, Belfast, 2016

Expansion machines and working fluids 3 rd EORC workshop, Belfast, 2016

Topologies 3 rd EORC workshop, Belfast, 2016

Models of components Expansion machine Model: Pump Model • • • Semi empirical model Fixed efficiencies Heat exchanger on the hot side semi empirical model Heat exchanger on the cold side • Tube and tube • Shell and tube • Plates 3 rd EORC workshop, Belfast, 2016 • Tube and tube • Shell and tube • Plates

Validation of the models Heat exchangers 3 rd EORC workshop, Belfast, 2016

Constraints and optimization variables Optimization variables Economic constraints Evaporating pressure Mass of the heat exchangers Pinch of the heat exchangers Constraints for WHR Built-in volume ratio Temperature of the EGR Heat rejection capacity Technical constraints Expander speed Limited speed Overheating degree Limited inlet temperature Gas mass fraction 3 rd EORC workshop, Belfast, 2016

Selection of the design conditions 3 rd EORC workshop, Belfast, 2016

Validation of the models Expansion machines • Simulation models for the volumetric expanders: • Calibration of the models on existing machines using experimental data. Ø References • Scaling of the parameters to adapt the models to the machine being currently designed (efficiencies). Scaling relations applied to the model parameters Model calibrated on a existing machine (reference) 3 rd EORC workshop, Belfast, 2016 Model of the machine being designed for the truck application

Design Additional constraints Expander technology Scroll Screw Piston Vane Rotational speed [RPM] <10000 <25000 500 -6000 <4000 Max. Inlet temperature [°C] Built-in volume ratio [-] 250 [2] 490 [3] >500 [4] <165 1. 5 -4. 1 4 -5 6 -14 2 -4. 5 Pressure ratio [-] 25 [5] 50 [6] Same as in ICE 3 rd EORC workshop, Belfast, 2016

Design Costs relations Example for a piston expander • Assumptions • Swashplate • 5 cylinders • Constant L/D ratio 3 rd EORC workshop, Belfast, 2016

Design Thermo-economic optimization 3 rd EORC workshop, Belfast, 2016

Design Thermo-economic optimization Screw expander, topology 5 and ethanol Net power output: 10. 9 k. W Evaporating pressure: 19 bar Condensing pressure: 1 bar Rotational speed: 25 krpm (6. 25 cm³) Overheating degree: 48 °C Built-in volume ratio: 6 3 rd EORC workshop, Belfast, 2016

Off-Design Optimization 3 rd EORC workshop, Belfast, 2016

Conclusion and perspectives • Help ORC designers to best select the expansion machine and working fluid for truck applications. • Preliminary design • Performance is not the only criteria • Decision array to select the components • Results are not general • Future work • Mixtures water/ethanol • Simulation of driving cycles 3 rd EORC workshop, Belfast, 2016

Questions Thank you 3 rd EORC workshop, Belfast, 2016

Bibliography • Technico-economicsurveyof. Organic. Rankine. Cycle(ORC) systems S. Quoilin, M. Van. Den. Broek, S. Declaye, Pierre. Dewallef, V. Lemort. • Experimental study and modeling of an Organic Rankine Cycle using scroll expander, S. Quoilin, V. Lemort, J. Lebrun. • Multi-objective optimization of organic Rankine cycles for waste heat recovery: Application in an offshore platform L. Pierobon, T. Van Nguyen, U. Larsen, F. Haglind, Brian Elmegaard. • European comission, Energy 2020, http: //ec. europa. eu/energy/ energy 2020/energy 2020. htm 2013. 3 rd EORC workshop, Belfast, 2016

Appendix Limit on the EGR temperature 3 rd EORC workshop, Belfast, 2016