Direct start of a gasoline direct-injection engine without a starter

When start–stop system technology is employed, the direct-start method without requiring a starter is considered to be a viable and low-cost solution for a gasoline direct-injection engine in a good thermal state to guarantee that the engine starts frequently and quickly. In this experimental work, the effects of the initial start conditions on successful realization of the direct-start method were investigated by using a four-cylinder gasoline direct-injection engine without considering the effect of the residual gas. Moreover, the changes in the combustion pressure and the rotational speed of the engine with different control parameters of the cylinders which were stopped on the compression and expansion strokes were examined, and the reliability and the stability of the direct-start method were analysed. Some control parameters have significant influences on the combustion pressure and the rotational characteristics of the crankshaft. The initial position of the piston stopped on the compression stroke and located between 60° crank angle before top dead centre and 70° crank angle before top dead centre is optimal to the direct-start method. The raised fuel pressure is beneficial for accomplishing a direct start, resulting in a lower fuel consumption and a shorter response time during the start. When the initial position of the piston is between 50° crank angle before top dead centre and 85° crank angle before top dead centre, the direct start method can still be realized successfully at an injection pressure of 0.5–2.3 MPa. From 50 tests, it was demonstrated that the direct-start method has a better reliability and a better stability at the initial piston position of 50°–85° crank angle before top dead centre, which acquired a nearly 100% probability that the gasoline direct-injection engine is successfully started with a variation in the rotational speed of less than 7%. The engine can almost reach the idle speed after the initial five working cycles. In comparison with the conventional start mode with a starter, the direct-start mode also has a better start response.

[1]  Ertugrul Taspinar,et al.  An Engine Start/Stop System for Improved Fuel Economy , 2007 .

[2]  Richard Stone,et al.  Effect of the valve timing and the coolant temperature on particulate emissions from a gasoline direct-injection engine fuelled with gasoline and with a gasoline–ethanol blend , 2012 .

[3]  Junya Tanaka,et al.  Fuel Consumption Improvement of Vehicles by Idling Stop , 2004 .

[4]  Wang Zhi,et al.  Research progress of high eff icient and clean combustion of automotive gasoline engines , 2010 .

[5]  Nabil G. Chalhoub,et al.  Exploration of the contribution of the start/stop transients in HEV operation and emissions , 2000 .

[6]  J.-H. Zhou,et al.  Calibration experiments on engine emission behaviour during the stopping-and-restarting process in a hybrid electric vehicle application , 2011 .

[7]  Li Xue-jun,et al.  First Cycle Ignition Characteristics During Warm Start of a Gasoline Direct Injection Engine , 2011 .

[8]  Sungwook Park,et al.  Numerical and experimental study of combustion and emission characteristics in gasoline direct-injection compression ignition engines using intake preheating , 2013 .

[9]  Michael Bargende,et al.  Einige Aspekte bezüglich Gemischbildung und Verbrennung im Rahmen des Direktstarts von Ottomotoren mit Benzin-Direkteinspritzung , 2003 .

[10]  Yang Jun-wei.  GDI Engine Warm Start Mode Assisted with Expansion Cylinder , 2012 .

[11]  Ricardo Novella,et al.  Implementation of the Partially Premixed Combustion concept in a 2-stroke HSDI diesel engine fueled with gasoline , 2014 .

[12]  S. Yu,et al.  Transient characteristics of emissions during engine start/stop operation employing a conventional gasoline engine for HEV application , 2008 .

[13]  Daniel Kok,et al.  Optimization potential of the vehicle launch performance for start—stop micro-hybrid vehicles , 2010 .

[14]  Yann Guezennec,et al.  On the control of engine start/stop dynamics in a hybrid electric vehicle , 2009 .

[15]  Yousef S.H. Najjar,et al.  Comparison of performance of a Greener direct-injection stratified-charge (DISC) engine with a spark , 2011 .

[16]  Manuel Valdés,et al.  Influence of the stop/start system on CO2 emissions of a diesel vehicle in urban traffic , 2011 .

[17]  Marco Chiodi,et al.  The Directstart: Investigation of Mixture Formation by Means of Optical Measurements and 3D-CFD-Simulation , 2005 .

[18]  Seongeun Yu,et al.  Investigation of engine restart stability after idle stop for a mild type HEV powertrain , 2013 .

[19]  David L. Harrington,et al.  Automotive Spark-Ignited Direct-Injection Gasoline Engines , 2000 .

[20]  Akihiko Minato,et al.  Investigation of premixed lean diesel combustion with ultra high pressure injection , 2005 .

[21]  C. Bae,et al.  Effects of the injection timing on spray and combustion characteristics in a spray-guided DISI engine under lean-stratified operation , 2013 .

[22]  Linda Gaines,et al.  Estimation of Fuel Use by Idling Commercial Trucks , 2006 .

[23]  Jae Seong Lee,et al.  Numerical investigation of the combustion characteristics and wall impingement with dependence on split-injection strategies from a gasoline direct-injection spark ignition engine , 2013 .

[24]  Ulrich Kramer,et al.  Experimental Determination of the Oxygen Concentration in the Start Cylinder of a Direct Started Engine , 2004 .

[25]  Hsiu-Ying Hwang,et al.  Engine automatic start–stop dynamic analysis and vibration reduction for a two-mode hybrid vehicle , 2013 .