Thermal efficiency and emission analysis of advanced thermodynamic strategies in a multi-cylinder diesel engine utilizing valve-train flexibility

Ding, Chuan Ph.D., Purdue University, December 2014. Thermal Efficiency and Emission Analysis of Advanced Thermodynamic Strategies in a Multi-cylinder Diesel Engine Utilizing Valve-train Flexibility . Major Professor: Dr. Gregory M. Shaver, School of Mechanical Engineering. Stringent emission regulations and a growing demand for fossil fuel drive the development of new technologies for internal combustion engines. Diesel engines are thermally efficient but require complex aftertreatment systems to reduce tailpipe emissions of unburned hydrocarbons (UHC), particulate matter (PM), and nitrogen oxides (NOx). These challenges require research into advanced thermodynamic strategies to improve thermal efficiency, control emission formation and manage exhaust temperature for downstream aftertreatment. The optimal performance for different on-road conditions is analyzed using a fully flexible valve-train on a modern diesel engine. The experimental investigation focuses on thermal management during idling and high-way cruise conditions. In addition, simulation are used to explore the fuel efficiency of Miller cycling at elevated geometric compression ratios. Thermal management of diesel engine aftertreatment is a significant challenge, particularly during cold start and extended idle operation. For instance, to be effective, NOx-mitigating selective catalytic reduction (SCR) systems require bed and gas inlet temperatures of at least 200◦C, and diesel oxidation catalysts coupled with upstream fuel injection require inlet temperatures of at least 300◦C in order to raise diesel particulate filter inlet temperatures to at least 500◦C for active regeneration. However, during peak engine efficiency idle operation, the exhaust temperatures only reach 120 and 200◦C for unloaded (800 rpm/ 0.26 bar BMEP) and loaded (800 rpm/ 2.5 bar BMEP) idle, respectively, for a typical modern-day diesel engine. For this and other engines like it, late injections or throttling (for instance via an over-closed

[1]  A. Abdel-azim.  Fundamentals of Heat and Mass Transfer , 2011 .

[2]  Bengt Johansson,et al.  FPGA Controlled Pneumatic Variable Valve Actuation , 2006 .

[3]  Song-Charng Kong,et al.  Performance Optimization of Diesel Engines with Variable Intake Valve Timing Via Genetic Algorithms , 2005 .

[4]  Frank Will,et al.  Combustion Simulations for a Self Controlling Variable Compression Ratio Connecting Rod , 2012 .

[5]  P. Dittrich,et al.  Thermodynamic Potentials of a Fully Variable Valve Actuation System for Passenger-Car Diesel Engines , 2010 .

[6]  Qianfan Xin,et al.  Overview of Diesel Engine Applications for Engine System Design - Part 2: General Performance Characteristics , 2011 .

[7]  P ? ? ? ? ? ? ? % ? ? ? ? , 1991 .

[8]  Alberto Boretti,et al.  Exploring the Advantages of Variable Compression Ratio in Internal Combustion Engines by Using Engine Performance Simulations , 2011 .

[9]  Hongming Xu,et al.  Promotive Effect of Diesel Fuel on Gasoline HCCI Engine Operated with Negative Valve Overlap (NVO) , 2006 .

[10]  Shuhn-Shyurng Hou,et al.  Performance analysis of an air-standard Miller cycle with considerations of heat loss as a percentage of fuel's energy, friction and variable specific heats of working fluid , 2008 .

[11]  Bengt Johansson,et al.  Investigation and Comparison of Residual Gas Enhanced HCCI using Trapping (NVO HCCI) or Rebreathing of Residual Gases , 2011 .

[12]  Zongxuan Sun,et al.  Late Intake Valve Closing as an Emissions Control Strategy at Tier 2 Bin 5 Engine-Out NOx Level , 2008 .

[13]  Ingemar Denbratt,et al.  HCCI Operation of a Passenger Car DI Diesel Engine with an Adjustable Valve Train , 2006 .

[15]  S. Charlton,et al.  Systems Engineering Approach for the Design of a Low Carbon, Fuel Efficient, Diesel Engine Powertrains for Commercial Vehicles , 2011 .

[16]  Donald W. Stanton,et al.  Diesel Engine Technologies Enabling Powertrain Optimization to Meet U.S. Greenhouse Gas Emissions , 2013 .

[17]  William De Ojeda,et al.  Effect of Variable Valve Timing on Diesel Combustion Characteristics , 2010 .

[18]  Rsg Rik Baert,et al.  Experimental study into a hybrid PCCI/CI concept for next-generation heavy-duty diesel engines , 2012 .

[19]  Philip Keller,et al.  Analysis of Diesel Engine Emissions Reduction by Late Intake Valve Close and VTG Turbocharger Using 1-D Simulation , 2008 .

[20]  L Kocher,et al.  Physically based volumetric efficiency model for diesel engines utilizing variable intake valve actuation , 2012 .

[21]  R Modiyani,et al.  Effect of intake valve closure modulation on effective compression ratio and gas exchange in turbocharged multi-cylinder engines utilizing EGR , 2011 .

[22]  Lyle Kocher,et al.  Estimation of effective compression ratio for engines utilizing flexible intake valve actuation , 2012 .

[23]  Jasim Ahmed,et al.  A physics-based approach to the control of homogeneous charge compression ignition engines with variable valve actuation , 2005 .

[24]  S. Chatterjee,et al.  Development of Emission Control Systems to Enable High NO x Conversion on Heavy Duty Diesel Engines , 2015 .

[25]  Yutaka Murata,et al.  Achievement of Medium Engine Speed and Load Premixed Diesel Combustion with Variable Valve Timing , 2006 .

[26]  Robert M. Wagner,et al.  Investigating Potential Light-duty Efficiency Improvements through Simulation of Turbo-compounding and Waste-heat Recovery Systems , 2010 .

[27]  Yiqiang Pei,et al.  High Density-Low Temperature Combustion in Diesel Engine Based on Technologies of Variable Boost Pressure and Intake Valve Timing , 2009 .

[28]  Chih Wu,et al.  Performance analysis and optimization of a supercharged Miller cycle Otto engine , 2003 .

[29]  R. Rudramoorthy,et al.  Variable compression ratio engine: A future power plant for automobiles - an overview , 2007 .

[30]  Richard Stobart,et al.  BSFC Investigation Using Variable Valve Timing in a Heavy Duty Diesel Engine , 2009 .

[31]  Yutaka Murata,et al.  Miller-PCCI Combustion in an HSDI Diesel Engine with VVT , 2008 .

[32]  Richard Stobart,et al.  Analysis of the Impact on Diesel Engine Fuel Economy and Emissions by Variable Compression Ratio Using GT-Power Simulation , 2010 .

[33]  Alberto Boretti,et al.  Exploring the Advantages of Atkinson Effects in Variable Compression Ratio Turbo GDI Engines , 2011 .

[34]  Gregory M. Shaver,et al.  Control-oriented PCCI combustion timing model for a diesel engine utilizing flexible intake valve modulation and high EGR levels , 2012, 2012 American Control Conference (ACC).

[35]  Rolf Johansson,et al.  Investigating Mode Switch from SI to HCCI using Early Intake Valve Closing and Negative Valve Overlap , 2011 .

[36]  Rahim Ebrahimi,et al.  Performance analysis of an irreversible Miller cycle with considerations of relative air–fuel ratio and stroke length , 2012 .

[37]  X. Bai,et al.  Effects of Negative Valve Overlap on the Auto-ignition Process of Lean Ethanol/Air Mixture in HCCI-Engines , 2010 .

[38]  James Turner,et al.  Fuel Economy Improvement Using Combined CAI and Cylinder Deactivation (CDA) - An Initial Study , 2005 .

[39]  Anthony Paul Roskilly,et al.  An analytic study of applying Miller cycle to reduce NOx emission from petrol engine , 2007 .

[40]  Federico Millo,et al.  Computational analysis of internal and external EGR strategies combined with Miller cycle concept for a two stage turbocharged medium speed marine Diesel engine , 2011 .

[41]  Alexander Rempel,et al.  Investigation of VVA-Based Exhaust Management Strategies by Means of a HD Single Cylinder Research Engine and Rapid Prototyping Systems , 2013 .

[42]  Akihiko Minato,et al.  Simultaneous Improvement of Fuel Consumption and Exhaust Emissions on a Multi-Cylinder Camless Engine , 2011 .

[43]  Donald W. Stanton,et al.  Systematic Development of Highly Efficient and Clean Engines to Meet Future Commercial Vehicle Greenhouse Gas Regulations , 2013 .

[44]  J. Christian Gerdes,et al.  Modeling cycle-to-cycle dynamics and mode transition in HCCI engines with variable valve actuation , 2006 .

[45]  Daisuke Akihisa,et al.  Research on Improving Thermal Efficiency through Variable Super-High Expansion Ratio Cycle , 2010 .

[46]  Fuwu Yan,et al.  Research on Temperature Characteristics of DPF Regeneration Technology Based on Catalytic Combustion of Fuel Injection , 2010, 2010 Asia-Pacific Power and Energy Engineering Conference.

[47]  Marco Warth,et al.  Integrated Simulation, Analysis and Testing of a Variable Valve Train for Passenger Car Diesel Engines , 2012 .

[48]  Marco Genova,et al.  An Electro-Hydraulic “Lost Motion” VVA System for a 3.0 Liter Diesel Engine , 2004 .

[49]  Margaret Lucas,et al.  What is Mechanical Engineering , 2011 .

[50]  G. B. Parvate-Patil,et al.  Analysis of Variable Valve Timing Events and Their Effects on Single Cylinder Diesel Engine , 2004 .

[51]  Michael Levin,et al.  Increasing Torque Output from a Turbodiesel with Camless Valvetrain , 2002 .

[52]  C. Edwards,et al.  Dynamic Modeling of Residual-Affected Homogeneous Charge Compression Ignition Engines with Variable Valve Actuation , 2005 .