EXPERIMENTAL INVESTIGATION OF A DIRECT INJECTION DUAL FUEL DIESEL-NATURAL GAS ENGINE
Presented by JAGADEESH PUTTA ME04B118 S8 ME 27
Department of Mechanical Engineering NATIONAL INSTITUTE OF TECHNOLOGY CALICUT KERALA- 673 601 Winter 2007-08
This is to certify that this seminar report entitled “EXPERIMENTAL INVESTIGATION OF A DIRECT INJECTION DUAL FUEL DIESEL-NATURAL GAS ENGINE “is a bonafide
record of the seminar presented by JAGADEESH PUTTA, Roll no:ME04B118, during winter semester 2007-08 in partial fulfilment of the requirement for the award of B.Tech degree in Mechanical Engineering by the National Institute of Technology, Calicut.
Faculty In-Charge of Seminar Department of Mechanical Engineering N.I.T. Calicut Dated: 16April 2008
1. Introduction 1.1 Methane as an Alternative Fuel 1.2 Dual Fuel 1.3 Effect of Injection 2. Combustion models 2.1 Theory 2.2 Combustion 2.3 Propagation of flame 3. Characterization of injector 4. Engine Tests 4.1 Engine setup 4.2 Driving cycles 4.3 Experimental parameters 4.4 Notations 4.5 Rate of heat release 5. Results and discussions 6. Conclusions 7. References
2 2 2 3 4 4 4 5 6 8 8 9 9 10 10 11 14 15
FIGURES AND TABLES
Figures Fig.1 Burning zone before combustion. Fig.2 Definition of burning zone after the initiation of combustion. Fig.3 Electric driving signal and pressure traces measured by a piezoresistive sensor (pinj=10bar, pbomb =2–6 bar). Fig.4 Picture of the methane flux taken with a CCD camera using the shadowgraphy technique. Fig.5 Experimental layout for the dynamic behavior of the injection system. Fig.6 Experimental layout for tests on the engine. Fig.7 Brake-specific emissions for the tested operating conditions Fig.8 Pressure and ROHR histories for the experiments in dual-fuel configuration. Fig.9 Pressure and ROHR histories for the experiments in dual-fuel configuration (n = 2000 rpm) when varying the diesel fuel quantity and pressure.
Tables Table 1 Engine Characteristics. Table 2 Engine Parameters set matrix.
LIST OF SYMBOLS
CNG injector cross-reference exit area (m2) Heat transfer area (m2) Rate of net heat release (J/CAD) Rate of heat transferred to the walls (J/CAD) D hc k L p pinj pbomb T Tw V W CNG injector poppet diameter (m2) Convective thermal coefficient (W/m2 K) Specific heats ratio CNG injector poppet lift (m2) Combustion chamber pressure (N/m2) CNG injection pressure (bar) Bomb pressure (bar). Combustion chamber bulk temperature (K) Combustion chamber walls temperature (K) Combustion chamber volume (m3) CNG flux direction (deg).
LIST OF ABBREVIATIONS ATDC BTDC BSCO BSTHC BSNOx BMEP CAD CNG CO ECU IVC NOx ROHR SOI THC Crank angle degrees After Top Dead center ( ) Crank angle degrees Before Top Dead center ( ) Brake specific carbon monoxide (g/kWh) Brake-specific total unburned hydrocarbons (g/kWh) Brake-specific nitric oxides (g/kWh) Brake mean effective pressure (bar) Crank angle degree (deg) Compressed natural gas Carbon monoxide Electronic control unit Inlet valve closing (deg) Nitric oxides Rate of heat release (J/CAD) Start of injection Total unburned hydrocarbons
ABSTRACT Automobiles represent one of the major portions of the cause of pollution production. As the stocks of the fuels are also decreasing, the need for new engines which run on fuels that cause lesser pollution and are more efficient is increasing. Methane can be a very promising as an alternative fuel as it can work with high compression ratios and low emissions. The report is about the experimental investigation of a single cylinder diesel engine that is converted into a dual-fuel engine to operate with natural gas as fuel. The CNG is injected into the intake manifold via a gas injector. This is ignited using pilot injection of diesel fuel. The main performance of the gas injector, such as flow coefficient, instantaneous mass flow rate, delay time between electrical...