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The Effect of Spark Plug Types on Engine Performance and Emissions

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The Effect of Spark Plug Types on Engine Performance and Emissions Palestine Polytechnic University College of Engineering The Effect of Spark Plug Types on Engine Performance and Emissions By Husam Qabaha Ahmad Yaseen Tayseer Zeada Supervisors: Dr. Zuhdi Salhab Submitted to College of Engineering in partial fulfillment of the requirements for the Bachelor degree in Automotive Engineering Hebron, May 2017 Abstract There are many different spark plug designs available in the market nowadays. Under- standing the differences between them is beneficial in helping the engine to run properly and efficiently. In the present study, a group of spark plugs with different characteristics by elec- trode gap, number of electrode, projection in cylinder and geometry of electrodes were chosen to explore their impact on the engine performance and emissions. In an attempt to enhance engine performance, smoothness and reducing fuel consumption and emissions. Keywords: spark plug,internal combustion engine, electrodes, emissions, fuel. úΫ Y«A AîDJ K. Q®Ë@ð ¨@ñKB@ èYë Ñê¯ ,ÐAK B@ èYë i. JK ÈAªJB@ HAªÖ Þ ¨@ñK@ áÓ YK YªË@ × ' ÈAªJB@ HAªÖÞ áÓ é«ñÒm. I. KQm. ÕæJ é@PYË@ èYë ú ¯ .AîEZA®» ©¯Pð ɯ@ ɾ. HA¿QjÖÏ@ ÉJ ª HAªÖ Þ X@YJÓ@ ð ,I. ËAË@ð I. k. ñÖÏ@I. ¢®Ë@ á K. é¯AÖÏ@ ð ,Aêʾ ð H. A¢¯B@ XY« IJ k áÓ é®ÊJjÖÏ@ H@ PA «ð @QgB@ éJ ÊÔ«ð ¼QjÖÏ@ Z@X@ úΫ HA ¯CJkB@ èYë QK@ é¯QªÓ ¬YîE. ,¼QjÖÏ@Ég@X úÍ@ ÈAªJ@B@ Xñ¯ñÊË Aê»CîD@ ÉJ Ê®K ð úÎg@YË@ @QgB@ HA¿Qm × Z@X@ á jJË éËðAm× ú¯ ,¼QjÖÏ@ áÓ èPXAË@ ÐXAªË@ .ÐXAªË@ H@ PA « éJ Ò» ÉJ Ê®Kð i Contents Abstract i 1 Introduction 1 1.1 Project Overview . .1 1.2 Project Objective . .3 1.3 Project Choice and Justification . .3 1.4 Time Table . .3 2 Spark Plug 6 2.1 Function . .6 2.2 Parts . .7 2.2.1 Terminal Stud . .8 ii 2.2.2 Insulator . .8 2.2.3 Shell . .8 2.2.4 Seal Seat . .9 2.2.5 Electrodes . .9 2.3 Spark Plug Concepts . 10 2.4 Electrode Gap . 12 2.5 Spark plug Performance . 13 2.6 Electrode Wear . 13 2.7 Abnormal Operating States . 14 2.8 Auto Ignition . 14 2.9 Combustion Knock . 14 3 Combustion and Emission 16 3.1 Ignition System . 16 3.2 Combustion and Flame . 18 3.2.1 Combustion stages . 18 iii 3.3 Factors Influencing the Flame Speed . 19 3.3.1 Turbulence . 20 3.3.2 Fuel-Air Ratio . 20 3.3.3 Engine Size . 20 3.4 Effect of spark Plug on Combustion . 21 3.4.1 Number of Electrodes . 21 3.4.2 Spark Plug Gap . 21 3.4.3 Projection of Spark Plug . 22 3.5 Emissions . 22 3.5.1 Introduction . 22 3.6 Exhaust Emissions . 23 3.6.1 Hydrocarbon (HC) . 23 3.6.2 Carbon Monoxide (CO) . 25 3.6.3 Oxygen (O2).................................. 26 3.6.4 Carbon Dioxide (CO2)............................ 26 iv 4 Test unit and equipment specifications 28 4.1 Spark Plug . 29 4.2 Test unit . 32 4.3 Steps of Experiment . 34 5 Data and Analyses 38 5.1 P-v and P-α ...................................... 38 5.2 Emission . 46 5.3 Conclusion . 52 5.4 Recommendation . 53 References 54 v List of Tables 1.1 Tasks description . .4 1.2 Time table . .5 4.1 Specification of spark plug with single electrode[3] . 29 4.2 Specification of spark plug with two electrode[2] . 30 4.3 Specification of spark plug with four electrode[2] . 31 4.4 Engine Specification . 33 5.1 Average of maximum pressure and maximum power . 45 5.2 Average of maximum pressure and maximum power . 45 5.3 Average of emission amounts . 51 5.4 Average of emission amounts . 51 vi List of Figures 1.1 Spark Plug in Gasoline Engine . .3 2.1 Spark Plug Parts . .7 2.2 Spark-plug concepts . 11 2.3 Electrode gap . 12 2.4 1 Normal combustion, 2 Combustion knock. 15 3.1 Ignition System . 17 3.2 Stages of Combustion in an SI Engines . 18 3.3 Relationship between equivalence ratio and emission concentration . 27 4.1 electrical dynamometer . 28 4.2 Block diagram of the system . 32 vii 4.3 Calibration of engine cycle analyzer . 34 4.4 Coupling . 35 4.5 Set TDC button and Rest . 35 4.6 Switches . 35 4.7 Connect icon . 35 4.8 Ammeter and Voltmeter . 36 4.9 Indicated power, mean effective pressure and engine speed . 36 4.10 Toggle icon between p-v and p-α .......................... 37 4.11 Loads . 37 5.1 PV one electrode at 2300rpm . 39 5.2 P α one electrode at 2300rpm . 39 5.3 PV two electrode at 2300rpm . 40 5.4 P α two electrode at 2300rpm . 40 5.5 PV four electrode at 2300rpm . 41 5.6 P α four electrode at 2300rpm . 41 viii 5.7 Maximum pressure values at a load of two coils . 42 5.8 Maximum pressure values at a load of four coils . 42 5.9 Mean Indicated Effective Pressure values at a load of two coils . 43 5.10 Mean Indicated Effective Pressure values at a load of four coils . 43 5.11 Indicated power values at a load of two coils . 44 5.12 Indicated power values at a load of four coils . 44 5.13 Emission analyzer . 46 5.14 Oxygen amounts at a load of two coils . 47 5.15 Oxygen amounts at a load of four coils . 47 5.16 Hydrocarbons amounts at a load of two coils . 48 5.17 Hydrocarbons amounts at a load of four coils . 48 5.18 Carbon monoxide amounts at a load of two coils . 49 5.19 Carbon monoxide amounts at a load of four coils . 49 5.20 Carbon dioxide amounts at a load of two coils . 50 5.21 Carbon dioxide amounts at a load of two coils . 50 ix Chapter 1 Introduction 1.1 Project Overview Internal combustion engine is an engine in which the combustion takes place internally. Combustion of a fuel occurs with an oxidizer, usually air in a combustion chamber. The com- bustion process in spark ignition engines plays a key role in the conversion of fuel energy into mechanical energy. The gasoline or spark-ignition (SI) internal combustion engine uses the Otto cycle and externally supplied ignition. It burns an air/fuel mixture and in the process converts the chemical energy in the fuel into kinetic energy. After ignition at the spark plug, the mixture of fuel and air starts to burn and continues burning until consuming the whole of the fuel of the charge in.
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