Effect of Delay Period on Performance of Compression Engine Running on Jatropha Fuel

Abstract Jatropha Biodiesel was tested in a single cylinder direct-injection, water cooled diesel engine to investigate the operational parameters of a small capacity diesel engine under five engine loads, constant speed test. The jatropha oil is used as a non edible oil to produce the biodiesel. The investigated blends were B0, B25, B50, B75 and B100, where (B#) denotes bio-diesel fuel volume percentage in diesel oil. The jatropha biodiesel was prepared locally in Sudan, specifications of which are given with reference to Petroleum Laboratories, Research and Studies Centre, Sudan. Each blend was tested on a short term basis and the results linked to ignition delay effect, a good firing was attained with the engine at various blends of jatropha bio-diesel blends in diesel oil fuel up to Bio-100 (pure biodiesel). Concerning ignition delay of the engine, which is a measure of ignition quality, it is less with low percentages of bio-fuel blends than that of high percentages. Finally it has been shown that blend (Bio75) was selected as a good blend since it has less mechanical friction loss, stability in exhaust heat loss, relatively good mechanical efficiency and, high stability in cooling engine heat loss.

Table of Contents

Number Description Page

Aya ii

Dedication iii

Acknowledgement iv

Abstract v

Abstract (Arabic) vi

List of Tables xi

List of Figures xii

Nomenclature (Symbols and Abbreviations) xiv

Chapter 1 Introduction

1.1 Introduction 2

1.2 Objectives 2

1.3 Scope and Limits 2

1.4 Problem statement 3

1.5 Questions of the Research 3

1.6 Significance 3

1.7 Methodology 4

Chapter 2 literature Review 5

2.1 Introduction 6

2.2 Bio-fuel and jatropha 6

2.3 Engine performance 8

vii

2.4 Ignition delay 9

Chapter 3 Fuels and Combustion 14

3.1. Internal Combustion Engines 15

3.1.1 Reciprocating IC engines 15

3.1.2 Two and Four Stroke engines 15

3.1.3 Fuel ignition in IC engines 16

3.1.4 Direct and indirect fuel injection in CI engines 16

3.1.5 Air intake and exhaust release in IC engines 17

3.2 Fuels General 17

3.2.1 Liquid Fuels 17

3.2.2 Bio-Fuels 17

3.2.3 Bio-Diesel 17

3.2.4 Jatropha and Jatropha Bio-Diesel 18

3.3 Combustion in Internal Combustion Engines 19

3.3.1 Combustion Characteristics in CI. Engines `19

3.3.2 Combustion Characteristics in SI. Engines 20

3.3.3 Delay Period 21

3.3.4 Ignition Delay Measurement 21

3.3.5 Factors affecting Ignition Delay 23

3.3.6 Combustion Stages in CI Engines 23

3.3.7 Fuel Ignition Quality 25

3.3.8 Knock in CI engines 29

3.4 Bio-fuels/Bio-diesel Blend 30

3.4.1 Bio-Fuels 30

3.4.2 Bio-diesel blend 30

Chapter 4 Experimental Work

viii

4.1 Test Rig Description and measurement Devices 32

4.1.1 Base Frame 32

4.1.2 DC Generator 32

4.1.3 Control Panel 33

4.1.4 Load bank 34

4.1.5 DC Generator Control 35

4.1.6 Exhaust Calorimeter 35

4.1.7 Auxiliary Cooling Unit 35

4.2 Engine Specifications 36

4.3 Performance Equations 38

4.4 Fuel Blends preparing 41

4.5 Data Collection and Calculation Equations of

Calculations 41

Chapter 5 Results and Discussion

5.1 Results 49

5.2 Discussion 56

5.2.1 Brake Power 56

5.2.2 Specific fuel consumption 58

5.2.3 Brake Mean Effective Pressure 58

5.2.3 Indicated Power 59

5.2.4 Mechanical Efficiency 60

5.2.5 Volumetric Efficiency 61

5.2.6 Equivalence Ratio 62

5.2.7 Ignition Delay 63

5.2.8 Thermal Efficiency 64