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High Efficiency Combustion Engines What is the limit? Prof. Bengt Johansson Lund University Slide 2 Outline Introduction The future is hard to predict Options Other combustion engines? Fuel cells? Batteries? Combustion engines What is high efficiency? Combustion, thermodynamic, gas exchange and mechanical efficiencies. All four must be high. What options do we have? Combustion to enable high efficiency Spark Ignition Compression Ignition HCCI Partially Premixed Combustion Can we do something about engine design? Conclusions Slide 3 Today 100.0% of all cars and trucks have internal combustion engines The total fleet is about 1.000.000.000 cars and trucks The electric fleet is less an 1.000.000 i.e. 0.1% Slide 4 Prediction is very difficult especially if it is about the future- Niels Bohr http://wattsupwiththat.com/2014/07/27/prediction-is-very-difficult-especially-about-the-future/ Slide 5 5 Newsweek April 28, 1975 Slide 6 Den som ser framt utan att se bakt fr se upp - Per Gillbrand Slide 7 Car of the future 1950-60: Gas turbine Slide 8 Timetable for Next Car Engine : The Gas Turbine and Its Future Business Week, April 2, 1955, page 134+ THEY ESTIMATE by 1960.................60,000 - 300,000 cars 1965................264,000 - 3,900,000 1970.............11,500,000 - 42,500,000 1975.............48,000,000 - 62,000,000 http://fuel-efficient-vehicles.org/energy-news/?page_id=943 Slide 9 Car of the future 1970: Stirling Slide 10 Car of the future 1980: . Slide 11 Car of the future 1990: Battery Electric GM EV-1 Slide 12 Car of the future 2000: Fuel Cell Slide 13 It is generally accepted that fuel cell vehicle production will follow a timeline as follows: Starting in 2002-4: First production FCVs tested on public roads in US, Europe and Japan in demonstration fleets. Around 2006-2007 Second generation fuel cell systems incorporated into FCVs and the expansion of FCV fleets in the US, Europe and Japan. Starting in 2010 Marketing of commercially viable FCVs at affordable prices - this will be the first step toward ultimately replacing the conventional internal combustion engine models. August 29, 2002, Bloomberg News : Larry Burns, GMs vice-president for R&D: GMs goal is to be the worlds first company to produce one million fuel cell vehicles a year, and that GM is looking to sell hundreds of thousands of fuel cell vehicles between 2010 and 2020 http://www.engr.uconn.edu/~jmfent/AutoCompaniesonFuelCells.pdf Slide 14 Car of the future 2010: Battery Electric Carlos Ghosn CEO Renault/Nissan 2010: Nissan Will Sell 500,000 Electric Cars a Year by 2013 He predicted that 10 percent of the world car market would be electric vehicles by 2020. There is no doubt in the minds of anyone in the industry that this is going to be a big factor in the industry, he said. Slide 15 Car of the future 2010: Battery Electric Reuters news flash Sept 14 2014: Nissan faces battery plant cuts as electric car hopes fade Ghosn dropped extra battery sites planned for both alliance carmakers, leaving Nissan with the entire production capacity of 220,000 power packs through the NEC joint venture, AESC. But that still far exceeds the 67,000 electric cars Renault- Nissan sold last year, and even the 176,000 registered to date. A pledge to reach 1.5 million by 2016 has been scrapped. Slide 16 Toyota: Elbilen behver Nobelprisbatteri 16 Tekniken som behvs fr att gra elbilar anvndbara r inte uppfunnen n -Krstrckan r s kort med en elbil, och laddtiden r s lng, summerar Kato. Med den teknikniv vi befinner oss p i dag behver ngon uppfinna ett batteri s bra att det vinner Nobelpris. Fr att kunna konkurrera med dagens bensindrivna bilar behvs s mycket batterier att det kar kostnaderna och laddtiderna. - Antalet kunder som r njda med elbilens korta rckvidd r begrnsad, sger han. Men blir intresset fr sdana bilar pltsligt strre, d r vi beredda att leverera. Av: Hkan Abrahamson, Ny teknik 10 juli 2014Hkan Abrahamson, Ny teknik 10 juli 2014 Slide 17 Toyota: Elbilen behver Nobelprisbatteri 17 I en intervju i Automotive News ger han tummen ner fr satsningen p elbilar, och sger att Toyota nu lgger sin tillverkning av elbilar. Fretaget tror att alternativet till bensin och diesel heter vtgas. Nsta r lanserar Toyota en brnslecellbil, och ven andra tillverkare ligger startgroparna med den sortens drivning. -Vid det laget erbjuder Toyota inte lngre ngon helt eldriven bil, sger Kato. De sm serier av elbilar som nu finns p programmet, minibilen eQ och RAV4 EV, lggs ner i slutet av det hr ret. Slide 18 Battery performance 18 Source: Private communications with Prabhakar Patil, CEO, LG Chem, Battery Div. Nov. 4, 2011 The active material for the anode and the cathode which are assumed to be a carbon-based anode (~2.7 g/Ah) and a Co-based cathode (~7.3 g /Ah) for the Li-ion cell. The specific capacity of the couple is therefore ~100 Ah/kg which combined with the voltage of 3.85 V for this couple leads to the 385 Wh/kg number Slide 19 Li-ion battery performance is now at 52% of theoretical limit 19 Source: Private communications with Prabhakar Patil, CEO, LG Chem, Battery Div. Nov. 3, 2011 40/250=0,160 55/245=0,225 55/315=0,175 70/370=0,189 80/240=0,333 20/810=0,025 20/135=0,148 70/570=0,123 180/790=0,228 130/459=0,283 200/385=0,519 Slide 20 20 Electric Vehicle Storage capacity 200 years Energy density increased 1 order of magnitude Specific energy increased a factor of 4-5 Even a low efficient ICE will have a better energy density and specific energy under normal running conditions. For the same rated power an electric vehicle is much heavier than a ICE. Cost of batteries! Source: Tarascon and D. Foster Keynote speech at ASME ICES 2009 Slide 21 21 Q: What is the similarity of a steam engine and a battery electric vehicle? A: They both run on coal Electric Vehicle Electricity source? www.cameco.com Slide 22 Summary on alternatives They have all promised much but delivered little! There is today not a viable alternative to the Internal Combustion Engine We must focus our little resources to improve what will be the prime mover of the future, not unrealistic scenarios The ICE can be improved very much in the future 22 Slide 23 Car of the future, today Smaller car with small ICE in combination with hybrid system. Fuel consumption of 0.67-1 l/100km ( Slide 24 Car of the future, in the future ? Slide 25 Car of the future, the Crystal Ball? ? German architect Andr Broessel of Rawlemon Slide 26 Outline Introduction The future is hard to predict Options Other combustion engines? Fuel cells? Batteries? Combustion engines What is high efficiency? Combustion, thermodynamic, gas exchange and mechanical efficiencies. All four must be high. What options do we have? Combustion to enable high efficiency Spark Ignition Compression Ignition HCCI Partially Premixed Combustion Can we do something about engine design? Conclusions Slide 27 Energy flow in an IC engine Slide 28 Combustion modes Spark Ignition (SI) engine (Gasoline, Otto) Compression Ignition (CI) engine (Diesel) Homogeneous Charge Compression Ignition (HCCI) Partially premixed combustion (PPC) Diesel HCCI Spark Assisted Compression Ignition (SACI) Gasoline HCCI + High efficiency + Ultra low NO x -Combustion control -Power density +Clean with 3-way Catalyst -Poor low & part load efficiency +High efficiency -Emissions of NO x and soot +Injection controlled - Less emissions advantage Slide 29 ICE research in Lund vs. time 199019952000200520102015 29 CCV=Cycle to Cycle Variations in Spark Ignition Engines GDI= Gasoline Direct Injection 2-S= Two Stroke engine VVT=Variable Valve Timing HCCI=Homogeneous Charge Compression Ignition SACI=Spark Assisted Compression Ignition PPC= Partially Premixed Combustion Slide 30 Emission focus vs. time 197019801990200020102020 30 Slide 31 31 HCCI -Thermodynamic efficiency Saab SVC variable compression ratio, VCR, HCCI, Rc=10:1-30:1; General Motors L850 World engine, HCCI, Rc=18:1, SI, Rc=18:1, SI, Rc=9.5:1 (std) Scania D12 Heavy duty diesel engine, HCCI, Rc=18:1; Fuel: US regular Gasoline SAE2006-01-0205 Slide 32 All four efficiencies 32 SAE keynote Kyoto 2007 Slide 33 Net indicated efficiency= C T GE SI std SI high HCCI VCR Scania +100% Slide 34 Brake efficiency SI std SI high HCCI VCR Scania Slide 35 Net indicated efficiency= C T GE SI std SI high HCCI VCR Scania 47% Slide 36 PPC - Diesel engine running on gasoline HCCI: i =47% => PPC: i =57% 36 Slide 37 Partially Premixed Combustion, PPC 37 Def: region between truly homogeneous combustion, HCCI, and diffusion controlled combustion, diesel HCCI PPC CI PCCI SAE 2004-01-2990 Slide 38 38 Experimental setup, Scania D12 Bosch Common Rail Prail max 1600[bar] Orifices8[-] Orifice Diameter0.18[mm] Umbrella Angle120[deg] Engine / Dyno Spec BMEPmax15[bar] Vd1951[cm3] Swirl ratio2.9[-] Fuel: Gasoline or Ethanol SAE 2009-01-2668 Slide 39 39 Efficiencies 17.1:1 SAE 2009-01-2668 Slide 40 40 4681012141618 50 55 60 65 70 75 80 85 90 95 100 Gross IMEP [bar] [%] Combustion Efficiency Thermal Efficiency Gas Exchange Efficiency Mechanical Efficiency Efficiencies 14.3:1 SAE 2010-01-0871 Slide 41 41 Emissions Better tuned EGR- combination Slide 42 42 Emissions different fuels SAE 2010-01-0871 Slide 43 43 Stable operational load vs. fuel type Tested Load Area Slide 44 44 Efficiency with Diesel or Gasoline D13 Diesel was calibrated by Scania to meet EU V legislation. Average improvement of 16.6% points at high load by replacing diesel fuel with gasoline! Slide 45 PPC Combustion Summary PPC has shown very high fuel efficiency Indicated efficiency of 57% at 8 bar IMEP Indicated efficiency of 55% from 5-18 bar IMEP With 70 RON fuel we can operate all the way from idle to 26 bar IMEP Emissions are below US10/Euro 6 without aftertreatment for NOx, PM, HC and CO! The fuel properties are critical for PPC load range 45 Slide 46 ICE research in Lund vs. time 199019952000200520102015 46 CCV=Cycle to Cycle Variations in Spark Ignition Engines GDI= Gasoline Direct Injection 2-S= Two Stroke engine VVT=Variable Valve Timing HCCI=Homogeneous Charge Compression Ignition SACI=Spark Assisted Compression Ignition PPC= Partially Premixed Combustion Slide 47 Energy flow in an IC engine Slide 48 High efficiency thermodynamics: Simulation results from GT-power Indicated efficiency 64% Brake efficiency 60.4% System layout is confidential Slide 49 Outline Introduction The future is hard to predict Options Other combustion engines? Fuel cells? Batteries? Combustion engines What is high efficiency? Combustion, thermodynamic, gas exchange and mechanical efficiencies. All four must be high. What options do we have? Combustion to enable high efficiency Spark Ignition Compression Ignition HCCI Partially Premixed Combustion Can we do something about engine design? Conclusions Slide 50 The future ICE Highest possible fuel efficiency Low enough emissions of NOx, PM, HC, CO Capable of using renewable fuels And the basic requirements of all products: Very high durability Low service requirements High power/mass ratio High power/volume ratio Low cost 50 Slide 51 Future Optimize the combustion process PPC Diesel Spark Ignition (prechamber) Improve the thermodynamics A compression ratio,R c of 70:1 and lean mixture (=1.38) gives a thermodynamic efficiency of 80%! Work with engine systems, not only details 51 Slide 52 What is the long term future? Active rate shaping What is the best Rate of Heat Release, RoHR, for maximum thermodynamic efficiency? The analog fuel injector with real time control of fuel flow and hence RoHR (with short ignition delay) using FPGA Fuels and engine interactions Best fuel for a combustion process Fuel flexible combustion process Natural gas/Biogas LNG/LBG-intercooler Hybrids The 2, 4, 6 concept Air Hybrid Heat transfer, coatings etc. 52 Slide 53 High Efficiency Combustion Engines What is the limit? It all starts at 40 and ends at 60 ( %engine efficiency that is, not life) Prof. Bengt Johansson Lund University Slide 54 Thank you! 54 Slide 55 High Efficiency Combustion Engines What is the limit? Prof. Bengt Johansson Lund University