STRATEGIES TO IMPROVE THE PERFORMANCE AND EMISSIONS OF DIESEL/BIODIESEL FUELED CI ENGINES USING SUPPLEMENTARY OXYGENATED
FUELS
By
MASOUD IRANMANESH
Department of Mechanical Engineering
Submitted
in fulfillment of the requirements of the degree of
DOCTOR OF PHILOSOPHY
To the
INDIAN INSTITUTE OF TECHNOLOGY, DELHI
January -2009
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L )I. L T. DELHI.
LIETZARY Acc.
3 8-26
TI1
-621.4436
CERTIFICATE
This is to certify that the thesis entitled, "Strategies To Improve The Performance and Emissions of Diesel/Biodiesel Fueled CI Engines Using Supplementary Oxygenated Fuels" being submitted by Mr. Masoud Irarunanesh to the Indian Institute of Technology Delhi, for the award of the degree of Doctor of Philosophy in Mechanical Engineering is a bonafide record of original research work carried out by him under our supervision, and has fulfilled the requirement for the submission of this thesis, which has attained the standard required for a PhD degree of this institute.
The results presented in this thesis have not .been submitted, in part or full, to any other university or institute for the award of any degree or diploma.
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...-OreDANINNAA,N2s4- tic I 114 i 4Dr. J. P. Subrahmanyam i '
rrYtt-P g--ct'Q''
Dr. M.K. G. Babu
Professor and Head Professor
Mechanical Engineering Department Center for Energy Studies Indian Institute of Technology Delhi Indian Institute of Technology Delhi New Delhi — 110016, India New Delhi — 110016, India
ACKNOWLEDGEMENTS
I thank GOD for seeing me through this journey of the present research and throughout all my Life. Like any other journey, this journey is associated with all kinds of challenges, achievements and failures and I express my sincere regards to all those who have contributed for the completion of my aim.
This project would not have been possible without the support of many people, and any merit in it is in large measure due to them. As Imam Ali, the first Imam of Shias, said, "Anybody teach me even one word, they would make me their servant,"
I would like to express my deepest gratitude to my supervisors Prof J.P.Subrahmanyam, Mechanical Engineering Department, and Prof M.K.G.Babu, Center for Energy Studies, IIT Delhi. Their knowledge of the subject and wealth of experience steered me to complete the work. Although the experimental part of this work was very hard like an ordeal to me due to some limitations and a lot of time have been wasted but it was a new experience for me to learn something new. In this regard the care, kind cooperation and encouragement of my supervisors have helped me to overcome all the hurdles and failures faced during this entire tenure.
I am grateful to my research committee members; Prof R.R. Gaur, Prof. P.M.V.
Subbarao and Prof L.M. Das (Centre of Energy Studies) for their comments, valuable suggestions and new ideas during the course of my work.
I acknowledge all the IIT Delhi professors and staff, who have contributed to my work and life during this academic period, and I found them very positive, kind and helpful. In between, I cannot ignore the roles of I.C.Engine lab members, especially Mr. Kuldip Singh, Mr. Narender Kumar, Mr. P.S. Negi, Mr. G.P.Singh (Center for energy studies), Mr. Pratap Chand (lubrication lab) and Mr Masoud-Ali (electronic lab) during the lab work in setting up the experimental setup and the usage of instruments is thankfully appreciated.
I gratefully acknowledge the Ministry of Science, Research and Technology of Iran;
Government of my lovely country, Iran, for the scholarship supplied to me under Quality Improvement Program, which has provided for me this opportunity to peruse my studies in PhD program and doing this research.
After all, I am forever indebted to my family, my kind spouse, Jaleh Tajaldini, who has provided calm environment at home and thoughtfully accepted all the responsibilities; Faezeh (my daughter) and Amir Ali (my son) for their patience; my mother for her prayer and love who without her prayers and blessings it would have been impossible for me to arrive at this stage.
Masoud Iranmanesh February 2, 2009 Mechanical Engineering Dept., IIT Delhi New Delhi, India
ii
Abstract
In this study a novel concept of dual fuelling a diesel engine with two types of supplementary oxygenates (ethanol and diethyl ether) and two baseline fuels (diesel and biodiesel) is presented. The concept, which was developed based on dual fueling, was investigated in the form of following categories:
- blending ethanol/DEE with diesel/biodiesel as base fuel - Fumigation of ethanol/DEE along with diesel/biodiesel
- Fumigation of DEE with a blend of ethanol with the base fuels(CFB technique) - Variable injection timing for the optimally selected blends
Characterization of blended fuel with oxygenates such as heating value, viscosity, density, distillation profile and miscibility show that addition of 10% vol. or less ethanol to diesel fuel makes the blend stable and more than 15% vol.ethanol made it unstable. In the Ethanol-Diesel (E-Diesel) mixture, the presence of DEE works as a co- solvent and enhances the stability of E-Diesel blends such that more than 10%vol, ethanol could be used in the blend; roughly, 1%vol. of DEE is required for every 3-4%vol. of ethanol addition. Density, kinematic viscosity and higher heating value of the blends decrease with the concentration of ethanol as well as DEE addition. The presence of ethanol and DEE increases the front-end volatility of the blends and decreases the boiling point in comparison to the baseline fuels.
Combustion and heat release analysis show that ethanol blending as well as fumigation increased ignition delay, peak pressure and peak HRR. Blending DEE decreased peak pressure and peak HRR, retarded start of heat release and increased ignition delay.
Fumigation of DEE reduced ignition delay and its peak pressure and peak HRR were higher than with blending. Combustion was started earlier by DEE fumigation and it shows that DEE plays as an ignition improver when introduced by fumigation along with ethanol blended fuels.
Evaluation of the engine performance and emissions characteristics resulted in improved brake thermal efficiency when. introducing ethanol and DEE to diesel fuel or
iii
biodiesel by blending or fumigation. BTE of ethanol blends were higher than both ethanol fumigation and DEE blends at the same ratio. DEE fumigation by CFB technique further improved BTE. Utilization of high percentage of DEE is limited by the erratic operation of the engine.
Smoke and NO emissions reduced with ethanol or DEE addition either by fumigation or by blending. The smoke reduction with ethanol blends was more than that with DEE blends. This is because the oxygen content of ethanol (-35%) is more than that of DEE (21%). A sharp reduction in NO„ emissions was seen with DEE addition. There was no significant difference between blending and fumigation method for reducing NO„ and smoke emissions. DEE fumigation (CFB technique) resulted in a further reduction of NO„ emission in comparison with DEE blending for both base fuels. However smoke emission with DEE fumigation was a little higher than that with DEE blending.
CO and HC emitted by ethanol or DEE .blends were higher than those for the corresponding neat base fuels. But there were some differences in the trends at lower and higher loads. In overall CO and HC emissions of biodiesel blends with ethanol and DEE for all the blends were observed to be less than those of diesel blends. DEE fumigation resulted in an increase of HC and CO emissions especially at lower loads in comparison with DEE or ethanol blends.
Addition of ethanol and DEE to diesel and biodiesel fuel caused a retardation of the dynamic injection timing and onset of ignition. It was found that a little advancement of injection timing can improve the overall emission and performance of diesel engine when operated with ethanol/DEE blends with diesel or biodiesel fuel.
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Table of Contents
Page No.
Acknowledgements
Abstract iii
Contents
List of Figures ix
List of Tables xx
Nomenclature xxii
1. INTRODUCTION 1-25
1.1. Status of Diesel Engines 1
1.2. Emissions formation, their Control and reduction in Diesel engines 2
1.2.1. Particles and Soot emissions 3
1.2.2. Oxides of Nitrogen 4
1.3. Alternative Oxygenated fuels 7
1.3.1. Ethanol and its utilization in diesel engine 11 1.3.1.1. Blending (Solution and stabilized emulsions) 12 1.3.1.2. Fumigation or Dual fuel aspiration 13
1.3.2. Diethyl ether (DEE) 14
1.3.3. Biodiesel 16
1.3.3.1. Historical background and International scenario 16
1.3.3.2. Biodiesel Production 16
1.3.3.3. Biodiesel Utilization in Diesel engines 18 1.4. Motivation and Objectives for the Present Work 20
1.5. Thesis contributions 22
1.6. Organization of the thesis 23
2. LITERATURE SURVEY 27-45
2.1. Introduction 27
2.2. Using Supplementary Oxygenated Fuels in Diesel Engine 27 2.2.1. Synthetic oxygenates and Soot-suppression tendency 28 2.2.2. Application of Different techniques 31
2.3. Utilization of Ethanol in Diesel Engines 33
2.3.1. Ethanol Blend in Diesel Engine 34
2.3.2. Ethanol Fumigation in Diesel Engine 36 2.4. Utilization of Diethyl Ether in Diesel Engines 37 2.5. Biodiesel Utilization in Diesel Engines 40 2.6. Remarks from Literature Reviewed and need for the present work 43 2.7. Research gaps for the present research 45
3. Experimental Setup and Test procedure 47-69
3.1. Test Procedure 47
3.2. Development of Experimental setup 48
3.3. Parameters measurement and relevant instrumentations 50
3.3.1. Engine Performance Parameters 51
3.3.1.1. Brake Power 51
3.3.1.2. Engine Speed 52
3.3.1.3. Air Consumption 52
3.3.1.4. Fuel Consumption 53
3.3.1.5: Temperature Measuring System 54
3.3.2. Exhaust Emissions measurement 54
3.3.3. Combustion characteristics 56
3.3.3.1. Crank angle encoding 56
3.3.3.2. Cylinder Pressure History Measuring System 57 3.3.3.3. Data acquisition and computer interfacing 59 3.4. Methodology of Engine Testing and implemented strategies 60
3.4.1. Blending Method 61
3.4.2. Fumigation Method 62
3.4.2.1.Fumigation by Carburetion 62 3.4.2.2.Fumigation by Electronic Inlet Injection 64
3.4.3. Variable Injection Timing 68
4. Evaluation of Blended Fuel properties 69
-86
4.1. Introduction 69
4.2. Stabilization test 70
vi
4.3. Distillation 75
4.4. Viscosity 78
4.5. Calorific Value 79
4.6. Density 82
4.7. Oxygen Content 83
4.8. Summary 85
5. Heat release and combustion analysis
5.1. Heat release rate 5.2. Heat transfer
5.3. Cylinder volume kinematics 5.4. smoothing graphs
5.5. calculation of combustion parameters
87-118
87 89 90 91 93
5.5.1. Start of injection 93
5.5.2. Start of combustion 93
5.5.3. Ignition delay period 95
5.5.4. Combustion duration 95
5.5.5. Cylinder Peak Pressure 95
5.6. Analysis of the Heat Release results 95
5.6.1. Effect of ethanol blending 96
5.6.2. Effect of Ethanol Fumigation 100
5.6.3. Effect of DEE Blending 103
5.6.4. Effect of DEE Fumigation 112
5.7. Statistical analysis 115
5.7.1. Uncertainty Analysis 116
5.7.1.1. Example: uncertainty in Brake Power 116
6. Results and discussions (Engine Emissions and Performance) 119-172
6.1. Blending Technique 119
6.1.1. Brake Thermal Efficiency 119
6.1.2. Smoke Opacity 125
6.1.3. NO,, emissions 129
6.1.4. Carbon Monoxide Emission 134
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6.1.5. Unburnt Hydrocarbon emissions 138
6.1.6. Summary 142
6.2. Fumigation technique 143
6.2.1. Brake thermal efficiency 143
6.2.2. Smoke Opacity 147
6.2.3. NO emissions 151
6.2.4. Carbon Monoxide Emission 155
6.2.5. Unburnt Hydrocarbon emissions 158
6.2.6. Summary 161
6.3. Variable Injection Timing (VIT) 162
6.3.1. Brake thermal efficiency 163
6.3.2. Smoke Opacity 165
6.3.3. NO emissions 167
6.3.4. Unburnt Hydrocarbon emissions 169
6.3.5. Carbon Monoxide Emission 170
6.3.6. Summary 172
7.
Conclusions 173
-177
7.1. Summary 173
7.2. Salient Features of the Results 174
7.3. Future Scope and Recommendations 176
References 179-189
Appendices 191-201
Appendix I:
Engine specifications 191Appendix II:
Accuracy of Instruments devices 192Appendix III:
Calibration Results for Fumigation system 193Appendix IV:
Specifications of Gas Analyzer and Smoke Meter 195 Appendix V: Specifications of Combustion analysis system 197Appendix VI:
Information of Statistical Analysis 200List of Publications
202Bio-Data
203viii
