Comparative study on combustion and thermodynamics performance of gasoline direct injection (GDI) engine under cold start and warm-up NEDC

2019 ◽  
Vol 181 ◽  
pp. 663-673 ◽  
Author(s):  
Qi Liu ◽  
Jingping Liu ◽  
Jianqin Fu ◽  
Yangyang Li ◽  
Baojun Luo ◽  
...  
Keyword(s):  
Comparative Study ◽  
Direct Injection ◽  
Cold Start ◽  
Gasoline Direct Injection ◽  
Warm Up ◽  
Gdi Engine

scholarly journals Investigation into the Relationship between Super-Knock and Misfires in an SI GDI Engine

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2099
Author(s):  
Jian Gao ◽  
Anren Yao ◽  
Yeyi Zhang ◽  
Guofan Qu ◽  
Chunde Yao ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Direct Injection ◽  
Exhaust Valve ◽  
Gasoline Direct Injection ◽  
Exhaust Pipe ◽  
Pressure Transducers ◽  
Spark Plug ◽  
Si Engines ◽  
Gdi Engine ◽  
The Relationship

The super-knock poses new challenges for further increasing the power density of spark ignition (SI) engines. The critical factors and mechanism connecting regarding the occurrence of super-knock are still unclear. Misfire is a common phenomenon in SI engines that the mixture in cylinder is not ignited normally, which is often caused by spark plug failure. However, the effect of misfire on engine combustion has not been paid enough attention to, particularly regarding connection to super-knock. The paper presents the results of experimental investigation into the relationship between super-knock and misfires at low speed and full load conditions. In this work, a boosted gasoline direct injection (GDI) engine with an exhaust manifold integrated in the cylinder head was employed. Four piezoelectric pressure transducers were used to acquire the data of a pressure trace in cylinder. The spark plugs of four cylinders were controlled manually, of which the ignition system could be cut off as demanded. In particular, a piezoelectric pressure transducer was installed at the exhaust pipe before the turbocharger to capture the pressure traces in the exhaust pipe. The results illustrated that misfires in one cylinder would cause super-knock in the other cylinders as well as the cylinder of itself. After one cylinder misfired, the unburned mixture would burn in the exhaust pipe to produce oscillating waves. The abnormal pressure fluctuation in the exhaust pipe was strongly correlated with the occurrence of super-knock. The sharper the pressure fluctuation, the greater the intensity of knock in the power cylinder. The cylinder whose exhaust valve overlapped with the exhaust valve of the misfired cylinder was prone to super-knock.

The Effects of Injection Timing and Injected Fuel Mass on Local Charge Conditions and Emissions for Gasoline Direct Injection Engines

2017 ◽  
Author(s):  
Doohyun Kim ◽  
Angela Violi ◽  
André Boehman
Keyword(s):  
Combustion Chamber ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Injection Timing ◽  
Charge Composition ◽  
Gaseous Species ◽  
Fuel Mass ◽  
Soot Precursors ◽  
Gdi Engine ◽  
Fuel Mixing

Increased Particulate Matter (PM) emissions from Gasoline Direct Injection (GDI) engines compared to conventional Port Fuel Injection (PFI) engines have been raising concerns because of the PM’s detrimental health effects and the stringent emissions regulations. One of the widely accepted hypotheses is that local rich pockets inside the combustion chamber are the primary reason for the increased PM emissions. In this paper, we investigate the effects of injection strategies on the charge composition and local thermodynamic conditions of a light duty GDI engine, and determine their impact on PM emissions. The operation of a 1.6L GDI engine is simulated using a 3-D Computational Fluid Dynamics (CFD) code. Combustion characteristics of a 3-component gasoline surrogate (n-heptane/iso-octane/toluene) are analyzed and the effects of injection timing (300° vs 240° vs 180° BTDC) and injected fuel mass (globally stoichiometric vs fuel rich) are explored at 2000 rpm, 9.5 bar BMEP condition, focusing on the homogeneity of the charge and the formation of the gaseous species that are soot precursors. The results indicate that when the physical time for air/fuel mixing is not long enough, fuel-rich pockets are present until combustion occurs, where high concentrations of soot precursors are found, such as acetylene and pyrene. In addition, simulation results indicate that the location of wetted surface as well as the in-cylinder flow structure induced by the fuel jet hitting the piston bowl is significantly influenced by varying the injection timing, which affects subsequent air/fuel mixing. When the injected fuel mass is increased, the equivalence ratio distribution inside the combustion chamber shifts toward fuel-rich side, generating more mixtures with Φ > 1.5, where formation of acetylene and pyrene are favored.

Idle Speed Control for GDI Engines with Interval Time-Delay

2012 ◽  
Vol 588-589 ◽  
pp. 1598-1601 ◽  
Author(s):  
Xue Jun Li ◽  
Wei Hong ◽  
Yan Su
Keyword(s):  
Control System ◽  
Direct Injection ◽  
Speed Control ◽  
Gasoline Direct Injection ◽  
Idle Speed ◽  
Idle Speed Control ◽  
Interval Delay ◽  
Gdi Engine ◽  
The Stability ◽  
Gdi Engines

The gasoline direct injection (GDI) engine is a highly non-linear and a delayed system. The engine modle with time-delays is derived. The delays consist of an intake to torque production state delay and a network -induced interval delay. Base on the Liapunov-Krasovskii function, the criterion of interval delay control system is proposed, which ensure the idle speed control system is stability as well as robust. The simulation results show that the H∞ control has good robustness,which improves the stability of the idle speed of the GDI engine.

The Research Progress of Particulate Emissions from Vehicles with Gasoline Direct Injection Engines

2013 ◽  
Vol 726-731 ◽  
pp. 2351-2354
Author(s):  
Guang Yang Liu ◽  
Yu Liu ◽  
Jian Xi Pang ◽  
Yan Qin
Keyword(s):  
Direct Injection ◽  
High Sensitivity ◽  
Cold Start ◽  
Gasoline Direct Injection ◽  
Research Progress ◽  
Particulate Emissions ◽  
Number Count ◽  
Direct Injection Engines ◽  
Driving Cycles ◽  
Particulate Number

The objective of this research is to introduce the main gasoline direct injection vehicle particulate emissions characteristics researches in the world. Many investigations of particulate sizing and number count from gasoline direct injection (GDI) vehicles at different driving cycles were performed. Lots of particulate emissions are measured for FTP-75, NEDC, HWTET, SC03, and US06 cycles and these cycles can reflect different aspects of the particulate emissions. In some papers, both engine-out and tailpipe emissions were measured. Some investigation showed high sensitivity of the particulate number or size distribution to changes with the engine control parameters including A/F, ignition timing, EOI and so on.On the whole, the particulate number during different Driving Cycle is shown along with further analysis of the transient particulate emissions. The cold start process obviously affects particulate formation. Even beyond cold start, the particulate number emissions decrease as the test progresses. The results coming from the particulate measurement system sampling directly from the exhaust showed very rapid increases in particulate emissions during engine transients.

Effect of Conical Spray and Multi-Hole Spray on Gasoline Engine Mixture Formation and Combustion Performance Based on Different Injection Strategies

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Shengli Wei ◽  
Zhiqing Yu ◽  
Zhilei Song ◽  
Fan Yang ◽  
Chengcheng Wu
Keyword(s):  
Gasoline Engine ◽  
Direct Injection ◽  
Mixture Distribution ◽  
Gasoline Direct Injection ◽  
Injection Timing ◽  
Mixture Formation ◽  
Injection Strategy ◽  
Gdi Engine ◽  
The Difference ◽  
Injection Strategies

Abstract This article presents a numerical investigation carried out to determine the effects of second and third injection timing on combustion characteristics and mixture formation of a gasoline direct injection (GDI) engine by comparing conical spray against multihole spray. The results showed that at the engine 80% full load of 2000 r/min, the difference in mixture distribution between the two sprays was obvious with double and triple injection strategies. With the second injection timing from 140 deg CA delay to 170 deg CA, the in-cylinder pressure, the in-cylinder temperature, and the heat release rate of the conical spray increased by 20.8%, 9.8%, and 30.7% and that of the multihole spray decreased by 30.7%, 13.6%, and 37.8%. The delay of the injection time reduced the performance of the engine with the multihole spray, and the performance of the multihole spray was obviously in the simulation of the triple injection strategy. However, for the conical spray, the application of the triple injection strategy increased the temperature and the pressure compared with the double injection strategy.

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