Offline and Real-Time Optimization of EGR Rate and Injection Timing in Diesel Engines

New methodologies have been developed to optimize EGR rate and injection timing in diesel engines, with the aim of minimizing fuel consumption (FC) and NOx engine-out emissions. The approach entails the application of a recently developed control-oriented engine model, which includes the simulation of the heat release rate, of the in-cylinder pressure and brake torque, as well as of the NOx emission levels. The engine model was coupled with a C-class vehicle model, in order to derive the engine speed and torque demand for several driving cycles, including the NEDC, FTP, AUDC, ARDC and AMDC. The optimization process was based on the minimization of a target function, which takes into account FC and NOx emission levels. The selected control variables of the problem are the injection timing of the main pulse and the position of the EGR valve, which have been considered as the most influential engine parameters on both fuel consumption and NOx emissions. The gear number has also been selected for optimization. One benchmark tool, which is based on the dynamic programming technique, and one real-time tool, which implements a static optimization method, have been developed for the optimization process. A new mathematical technique has been introduced and applied in order to decrease the computational time of the optimizers to a great extent. It was verified that the real-time method has the potential of being implemented in the engine control unit (ECU), in order to realize an onboard optimization of the selected engine and vehicle parameters

[1]  Timothy J. Callahan,et al.  Homogeneous Charge Compression Ignition of Diesel Fuel , 1996 .

[2]  P. F. Flynn,et al.  Development of a Single Cylinder Compression Ignition Research Engine , 1965 .

[3]  Andrea Catania,et al.  Real-Time Calculation of EGR Rate and Intake Charge Oxygen Concentration for Misfire Detection in Diesel Engines , 2011 .

[4]  Yixin Yang,et al.  Use of an Innovative Predictive Heat Release Model Combined to a 1D Fluid-Dynamic Model for the Simulation of a Heavy Duty Diesel Engine , 2013 .

[5]  Raouf Mobasheri,et al.  Analysis the effect of advanced injection strategies on engine performance and pollutant emissions in a heavy duty DI-diesel engine by CFD modeling , 2012 .

[6]  Gian Marco Bianchi,et al.  A Numerical Methodology For The Multi-Objective Optimization Of The DI Diesel Engine Combustion , 2014 .

[7]  Ezio Spessa,et al.  Calculation of mass emissions, oxygen mass fraction and thermal capacity of the inducted charge in SI and diesel engines from exhaust and intake gas analysis , 2011 .

[8]  Evangelos G. Giakoumis,et al.  Review of Thermodynamic Diesel Engine Simulations under Transient Operating Conditions , 2006 .

[9]  C. D. Rakopoulos,et al.  Investigation of piston bowl geometry and speed effects in a motored HSDI diesel engine using a CFD against a quasi-dimensional model , 2010 .

[10]  Ezio Spessa,et al.  Ignition delay prediction of multiple injections in diesel engines , 2014 .

[11]  Ugur Kesgin,et al.  Genetic algorithm and artificial neural network for engine optimisation of efficiency and NOx emission , 2004 .

[12]  F. Chmela,et al.  Rate of Heat Release Prediction for Direct Injection Diesel Engines Based on Purely Mixing Controlled Combustion , 1999 .

[13]  Nigel N. Clark,et al.  NEURAL NETWORK MODELLING OF THE EMISSIONS AND PERFORMANCE OF A HEAVY-DUTY DIESEL ENGINE , 2000 .

[14]  Ezio Spessa,et al.  Real-Time Predictive Modeling of Combustion and NO x Formation in Diesel Engines Under Transient Conditions , 2012 .

[15]  Gianluca D'Errico,et al.  Integrated 1D-MultiD Fluid Dynamic Models for the Simulation of I.C.E. Intake and Exhaust Systems , 2007 .

[16]  Andrea Catania,et al.  Experimental Analysis of Combustion Processes and Emissions in a 2.0L Multi-Cylinder Diesel Engine Featuring a New Generation Piezo-Driven Injector , 2009 .

[17]  Akio Matsunaga,et al.  A New Dynamic Combustion Control Method Based on Charge Oxygen Concentration for Diesel Engines , 2003 .

[18]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[19]  Rolf D. Reitz,et al.  CFD simulations of diesel spray tip penetration with multiple injections and with engine compression ratios up to 100:1 , 2013 .

[20]  Andrea Catania,et al.  Predictive zero-dimensional combustion model for DI diesel engine feed-forward control , 2011 .

[21]  Ezio Spessa,et al.  Layout design and energetic analysis of a complex diesel parallel hybrid electric vehicle , 2014 .

[22]  Rolf Egnell,et al.  Modelling Diesel Engine Combustion and NOx Formation for Model Based Control and Simulation of Engine and Exhaust Aftertreatment Systems , 2006 .

[23]  Andrea Catania,et al.  Combined application of CFD modeling and pressure-based combustion diagnostics for the development of a low compression ratio high-performance diesel engine , 2007 .

[24]  Shigeki Nakayama,et al.  An Application of Model Based Combustion Control to Transient Cycle-by-Cycle Diesel Combustion , 2008 .

[25]  Carlo Alberto Rinaldini,et al.  CFD-3D Analysis of a Light Duty Dual Fuel (Diesel/Natural Gas) Combustion Engine , 2014 .

[26]  Rolf Egnell.  A Simple Approach to Studying the Relation between Fuel Rate Heat Release Rate and NO Formation in Diesel Engines , 1999 .

[27]  Matteo Giacopini,et al.  Multiphase CFD–CHT optimization of the cooling jacket and FEM analysis of the engine head of a V6 diesel engine , 2013 .

[28]  Rolf Egnell,et al.  Transient Emission Predictions With Quasi Stationary Models , 2005 .

[29]  Ezio Spessa,et al.  HRR and MFB50 estimation in a Euro 6 diesel engine by means of control-oriented predictive models , 2015 .

[30]  G. Nagarajan,et al.  Optimization of DI Diesel Engine Operating Parameters Using a Response Surface Method , 2010 .

[31]  Ezio Spessa,et al.  A control-oriented real-time semi-empirical model for the prediction of NOx emissions in diesel engines , 2014 .

[32]  Mohamed Abid,et al.  Influence of intake manifold design on in-cylinder flow and engine performances in a bus diesel engi , 2011 .

[33]  Rolf D. Reitz,et al.  Optimization of Heavy-Duty Diesel Engine Operating Parameters Using A Response Surface Method , 2000 .

[34]  Ezio Spessa,et al.  Optimization of the Layout and Control Strategy for Parallel Through-the-Road Hybrid Electric Vehicles , 2014 .

[35]  Alan Keromnes,et al.  Development and validation of a 5 stroke engine for range extenders application , 2014 .

[36]  B. Jayashankara,et al.  Effect of fuel injection timing and intake pressure on the performance of a DI diesel engine – A parametric study using CFD , 2010 .

[37]  Paul C. Miles,et al.  A Computational Investigation of the Effects of Swirl Ratio and Injection Pressure on Mixture Preparation and Wall Heat Transfer in a Light-Duty Diesel Engine , 2013 .

[38]  Aleš Hribernik,et al.  Numerical and experimental study of combustion, performance and emission characteristics of a heavy-duty DI diesel engine running on diesel, biodiesel and their blends. , 2014 .

[39]  Johan Lennblad,et al.  Neural Network Based Fast-Running Engine Models for Control-Oriented Applications , 2005 .