ORC for Heavy Duty Trucks M. Hombsch a , K. Shariatmadar a , D. Maes - PowerPoint PPT Presentation

Experimental Investigation of Waste Heat Recovery Using an ORC for Heavy Duty Trucks M. Hombsch a , K. Shariatmadar a , D. Maes b , P. Garsoux c a Dana Belgium NV, b Flanders Make VZW, c Bosal Emissions Control Systems NV 4 th Engine ORC Consortium Workshop November 15 - 17, Detroit, Michigan 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Design methodology and system optimization tool – Flanders Make ORC design challenges Engine heat sources Brake 2 Evaporator Power ( heat source) 42% Fuel Energy 100% 1 Pum p 3 Expander 8% Friction / Misc. Losses Heat 24% Transfer Exhaust 26% Engine Cooling Quality Low Waste Heat 4 Condenser Energy 80-100°C ( heat sink) EGR Cooling Quality High Waste Heat Charge Air Cooling 200-750°C Working fluids 20-60°C Tailpipe • Water • Ethanol 200-600°C • Butane • Refrigerant 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Design methodology and system optimization tool Use case specification Heat sources (averaged) • Exhaust 0.204 kg/s, 354 °C • EGR 0.081 kg/s, 520 °C Heat sink (averaged) EGR only Exhaust only EGR first • Cooling water 1.5 kg/s, 60°C Topological variations • Six evaporator configurations Exhaust first EGR split Parallel • Recuperator not useful • EGR replacement (cost saving from existing cooler) 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Design methodology and system optimization tool Optimization • Changes components size and thermal cycle • Constrained nonlinear programming • Exhaustive search over fluids and topologies Maximize expander power Minimize cost / net power 225 days*. . 403 days* . *assuming 11 hour driving per day 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Design methodology and system optimization tool Dynamic model in Amesim p 3 4 Condenser 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Design methodology and system optimization tool Control Design 2 Evaporator ( heat source) 1 Pum p 3 Expander 4 Condenser ( heat sink) 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Design methodology and system optimization tool Control Design - Control of evaporator pressure PI + feedforward + decoupling Model based control simplest to implement better constraint handling 32 32 31 31 30 30 29 29 28 28 27 27 26 26 25 25 500 1000 1500 2000 2500 500 1000 1500 2000 2000 2500 Time in seconds Time in seconds 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Heat exchanger development – Bosal Non-dimensional evaporator sizing • NTU method (Number of Tranfer Units) ∞ Δ𝑈 𝑑𝑞 , 𝐷 𝑠 , 𝑇𝑢, 𝐾𝑏 −1 , • Non dimensional numbers, 𝑂𝑈𝑉 = 𝑔 𝑠 𝑡ℎ 𝑡𝑑 , … −Δ𝑈 – Heat capacity ratio 𝑠 𝑑𝑞 , heat cap. rate ratio 𝐷 𝑠 , Stanton number 𝑇𝑢 – Inverse Jacob number 𝐾𝑏 −1 (phase change) ∞ Δ𝑈 𝑡ℎ – Ratio of superheating to subcooling −Δ𝑈 𝑡𝑑 • No working fluid “hard coded” in calculations 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Heat exchanger development – Bosal Evaporator size optimization for HD trucks • Target: minimum pay-back for total WHR system • Inputs – Tool developed by Flanders Make – Bosal evaporator model – Bosal cost model – European operating conditions • Assumptions – Exhaust & EGR evaporators – Working fluid: Alcohol based – Volumetric expander – ...  Evaporator size minimizing €/W 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Heat exchanger development – Bosal Stability of evaporation process • Slope of -2 (-20dB/decade), indicating higher frequency massflow oscillations do not affect the outlet temperature significantly Raw signal, Temperature oscillation Water Massflow oscillation dm air Temperature Power Frequency [Hz] Time [s] Transfer function Air Massflow oscillation dm air Amplification Power Frequency [Hz] Frequency [Hz] 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Heat exchanger development – Bosal Heat exchanger performance • More than 50 sensors (T, p,ṁ ) • Heat transfer validation in 2-phase flow Set of operating points Sequenced perturbations 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Flow validation – Voxdale CFD validation • Pipe bundle replaced with porous blocks • Heat exchange inside blocks • Nonlinear pressure drop in X and Y direction • Wall temperature given as boundary condition Results • Flow uniformity HEX core Bypass • Bypass duct optimization www.voxdale.be info@voxdale.be 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Heat exchanger development – Bosal Hardware built: Evaporator Fluid • Modular design, different working fluids possible • High Pressure operation (60 bar) • Proven in-field operation • To be integrated in Euro VI muffler • Add-on with bypass Evaporator Gas Bypass Euro VI truck muffler WHR add-on 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Coolant tank 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Prototypes: Bosal evaporators Exoès expander Tube & shell heat exchanger double-acting swashplate piston expander 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Experimental results 2 Evaporator ( heat source) Power P transferred to the cycle fluid [kW] 0 10 20 30 40 50 60 1 Pum p 3 Expander 400 732 Experiment 350 632 Temperature T [°F] 300 4 Condenser 532 Temperature T [°C] ( heat sink) 250 432 2 200 332 3 150 232 100 1 4 132 50 0 32 -36 164 364 564 764 964 1,164 1,364 Cycle fluid enthalpy h [kJ/kg] 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Thermal efficiency Net fuel savings 12 12% 5% Maximum Power tested Conservative (Conservative assumption) Maximum Power 10% 10 assumption 4% Raw thermal efficiency Raw output power [kW] 8 8% Fuel savings 3% 6 6% 2% 4 4% Includes: Engine back pressure, 1% - Engine back pressure loss 2 2% Pump consumption - Pump consumption 0% 0% 0 0 50 100 150 200 250 300 0 50 100 150 Equivalent shaft power [kW] Waste heat exploited [kW] 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Sankey diagram for highway cruise Coolant: Ambient: Coolant: 44% 53% 29% Exhaust 6% Turbine Exhaust 12% 6% 17% 3% Charge air 5% manifold: 15% WHR: Fuel: 29% 11% EGR: 12% 17% 100% 2% WHR gain, Brake Brake 11% from WHR input power: 4% from brake power power 45% + WHR: 47% 1% 2% 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Drive cycle analysis: GEM model • 340 kW (455 hp) model year 2018 engine, 6x4 configuration • Applied fuel usage weighting to time spent in given power • Weighted average of three drive cycles: – Urban – 55 mph with slopes – 65 mph with slopes 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Drive cycle analysis: average fuel savings Mean fuel savings 3.5% 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Test bench and experimental results Yearly savings, US sleeper cab 𝑙𝑛 𝑛𝑗𝑚𝑓𝑡 190,200 118,200 𝑧𝑓𝑏𝑠 , first three years, sleeper cab* 𝑧𝑓𝑏𝑠 𝑚 ∗ 33.3 7.06 𝑛𝑞𝑕 , Model Year 2018 GEM simulation 100𝑙𝑛 $ $ ∗ 1.04 3.94 𝑕𝑏𝑚 EIA 2025 retail +10.5% local tax 𝑚 ∗ 3.5% WHR system fuel econemy improvement € 100 maintenance -$ 105 = $ 𝟑𝟑𝟏𝟏 Yearly savings 2025 3,56 $/gal + 10.5% local tax  Payback time ca. 2 years Today = 3.94 $/gal 2.65 $/gal+28¢ local tax = 2.93 $/gal 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Conclusions • Design methodology tool developed for ORC WHR – Pre-design tool for selection and size of components – Optimizing total cost of ownership – Steady-state design with dynamic evaluation – Introduction of possible control strategies • Hardware – ORC Test bench running on Diesel exhaust – Exhaust heat exchanger prototypes from Bosal, sized using TCO analysis – Expander prototype from Exoès, tailored for HD truck market • Test results – Amesim model calibrated using static and dynamic tests – Peak thermal efficiency of 11%, net drivecycle fuel saving 3.5% – Payback time of 2 years for a WHR system 4th EORCC Workshop, Detroit 2017

Experimental ORC - WHR for Heavy Duty Trucks Questions Maximilian Hombsch maximilian.hombsch@dana.com Keivan Shariatmadar keivan.shariatmadar@dana.com Davy Maes davy.maes@flandersmake.be Stephan Schlimpert stephan.schlimpert@flandersmake.be Stefan Pas stefan.pas@ext.bosal.com Filip Dörge filip.dorge@bosal.com 4th EORCC Workshop, Detroit 2017