Split injection flash boiling spray for high efficiency and low emissions in a GDI engine under lean combustion condition

2020 ◽  
Author(s):  
Zhe Sun ◽  
Mingli Cui ◽  
Chang Ye ◽  
Shangze Yang ◽  
Xuesong Li ◽  
...  
Keyword(s):  
High Efficiency ◽  
Combustion Condition ◽  
Split Injection ◽  
Lean Combustion ◽  
Gdi Engine ◽  
Flash Boiling

scholarly journals Super-knock Suppression Using Split Injection in a Turbo-Charged GDI Engine

2016 ◽  
Vol 40 ◽  
pp. 02011 ◽  
Author(s):  
Meng Lv ◽  
Yun Li ◽  
Xiaoming Hu ◽  
Yongchen Liu ◽  
Lv Chang
Keyword(s):  
Split Injection ◽  
Gdi Engine

Effect of Split Injection Timing on Combustion and Emissions of a DISI Optical Engine Under Lean Burn Condition

2020 ◽  
Author(s):  
Zhe Sun ◽  
Mingli Cui ◽  
Hongyu Wang ◽  
Mohamed Nour ◽  
Xuesong Li ◽  
...  
Keyword(s):  
High Energy ◽  
Flame Speed ◽  
Operating Conditions ◽  
Image Processing Technique ◽  
Injection Timing ◽  
Split Injection ◽  
Lean Burn ◽  
Combustion Performance ◽  
Optical Engine ◽  
Lean Combustion

Abstract Lean combustion has proven to be an effective way to improve the efficiency and emissions of the direct injection spark ignition (DISI) engine. However, one of the main problems at the lean stability limit is the major decrease in flame temperature due to dilution, resulting in a low laminar flame speed, especially under low-speed engine operating conditions. The split injection is a potential technology to realize proper air-fuel mixing and achieve different spray distribution that can help in solving such problems. In this study, split injections with different secondary injection timings were tested to achieve homogeneous and homogeneous-stratified modes in a DISI optical engine under lean-burn mode. The split ratio of each strategy was 1:1. The engine was operated at 800 rpm, and a high-energy ignition system was utilized to realize lean combustion at a lambda of 1.55. Engine combustion performance and emissions were tested while performing high-speed color recording to study the characteristics of flame chemiluminescence through a quartz piston combined with a 45-degree mirror installed below. Flame structure during various combustion phases was compared under different selected conditions based on a digital image processing technique. The results show that the pressure and emissions vary with the second injection timing. Proper control of the split injection timing can improve lean combustion performance, including faster flame speed, increased indicated mean effective pressure (IMEP), and lower harmful emissions. Poor fuel evaporation and soot generation from spatial hot spots in the combustion process of split injection are the major challenges for further improvement.

Ethanol Lean Combustion Characteristics of a GDI Engine

2015 ◽  
Vol 798 ◽  
pp. 219-223
Author(s):  
Roberto B.R. Costa ◽  
Carlos A.J. Gomes ◽  
Fabricio J.P. Pujatti ◽  
Ramon Molina Valle ◽  
José E.M. Barros
Keyword(s):  
Engine Speed ◽  
Injection Pressure ◽  
Combustion Stability ◽  
Lean Burn ◽  
Engine Efficiency ◽  
Lean Combustion ◽  
Excess Air ◽  
Wide Range ◽  
Ethanol Combustion ◽  
Gdi Engine

In the present study, ethanol combustion analysis was carried in a wall guided type GDI engine, to achieve combustion stability under lean burn operation and to expand the flammability limit for increasing engine efficiency. Tests were performed at constant engine speed, load and injection pressure (1000 rpm, NIMEP = 3 bar, 100 bar), for a wide range of injection, ignition and mixture formation parameters. NISFC, combustion stability, PMEP and burn duration were evaluated at each excess air ratio. An improvement on fuel economy and, consequently, increased engine efficiency was achieved for excess air ratios of λ = 1.1 and λ = 1.2.

Structure of Combustion Enhancement on Impinging Diffusion Flame

2012 ◽  
Vol 152-154 ◽  
pp. 872-876
Author(s):  
Jai Houng Leu ◽  
Ay Su
Keyword(s):  
Diffusion Flame ◽  
Peak Temperature ◽  
Combustion Condition ◽  
Mixing Rate ◽  
Nitrogen Gas ◽  
Lean Combustion ◽  
Temperature Distributions ◽  
Pure Methane ◽  
Combustion Enhancement ◽  
Impinging Flame

For the purpose to clear obverse the impingement and entrainment of the impinging diffusion flame, numbers of the tests are executed under various sets of momentum ratios in this paper. The oxidizer-fuel impinging flames shorten the fully development length. The peak temperature distributions are also greater than that of pure methane impinging flame. Furthermore, its flame width in YZ plane is thicker than that of the pure impinging flame. This effect is more obvious under lean combustion condition. Also, nitrogen gas in the mixture can increase the mixing rate.

scholarly journals Flame Front and Burned Gas Characteristics for Different Split Injection Ratios and Phasing in an Optical GDI Engine

2019 ◽  
Vol 9 (3) ◽  
pp. 449 ◽  
Author(s):  
Santiago Martinez ◽  
Simona Merola ◽  
Adrian Irimescu
Keyword(s):  
Flame Front ◽  
Soot Formation ◽  
Direct Injection ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Optical Data ◽  
Cylinder Pressure ◽  
Split Injection ◽  
Gdi Engine ◽  
Injection Strategies

Direct-injection in spark-ignition engines has long been recognized as a valid option for improving fuel economy, reducing CO2 emissions and avoiding knock occurrence due to higher flexibility in control strategies. However, problems associated with mixture formation are responsible for soot emissions, one of the most limiting factors of this technology. Therefore, the combustion process and soot formation were investigated with different injection strategies on a gasoline direct injection (GDI) engine. The experimental analysis was realized on an optically accessible single cylinder engine when applying single, double and triple injection strategies. Moreover, the effect of fuel delivery phasing was also scrutinized by changing the start of the injection during late intake- and early compression-strokes. The duration of injection was split in different percentages between two or three pulses, so as to obtain close to stoichiometric operation in all conditions. The engine was operated at fixed rotational speed and spark timing, with wide-open throttle. Optical diagnostics based on cycle resolved digital imaging was applied during the early and late stages of the combustion process. Detailed information on the flame front morphology and soot formation were obtained. The optical data were correlated to in-cylinder pressure traces and exhaust gas emission measurements. The results suggest that the split injection of the fuel has advantages in terms of reduction of soot formation and NOx emissions and a similar combustion performance with respect to the single injection timing. Moreover, an early injection resulted in higher rates of heat release and in-cylinder pressure, together with a reduction of soot formation and flame distortion. The double injection strategy with higher percentage of fuel injected in the first pulse and early second injection pulse showed the best results in terms of combustion evolution and pollutant emissions. For the operative condition studied, a higher time for mixture homogenization and split of fuel injected in the intake stroke shows the best results.

The Use of Split-Injection Technique and Ethanol Lean Combustion on a SIDI Engine Operation for Reducing the Fuel Consumption and Pollutant Emissions

2017 ◽  
Author(s):  
Thiago R. V. Silva ◽  
José G. C. Baeta ◽  
Nilton A. D. Neto ◽  
Augusto C. T. Malaquias ◽  
Matheus G. F. Carvalho ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Pollutant Emissions ◽  
Injection Technique ◽  
Split Injection ◽  
Engine Operation ◽  
Lean Combustion

The influence of flash boiling conditions on spray characteristics with closely coupled split injection strategy

2017 ◽  
Vol 187 ◽  
pp. 523-533 ◽  
Author(s):  
Ziman Wang ◽  
Changzhao Jiang ◽  
Hongming Xu ◽  
Tawfik Badawy ◽  
Bo Wang ◽  
...  
Keyword(s):  
Split Injection ◽  
Spray Characteristics ◽  
Injection Strategy ◽  
Flash Boiling
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