Study on exhaust system parameters for fuel economy improvement of small gasoline engine

2009 ◽  
Author(s):  
Peng He ◽  
Yunqing Li ◽  
Lifeng Zhao
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Exhaust System ◽  
System Parameters ◽  
Fuel Economy Improvement

Comparison of Fuel Economy Improvement by High and Low Pressure EGR System on a Downsized Boosted Gasoline Engine

2017 ◽  
Author(s):  
Yuedong Chao ◽  
Haifeng Lu ◽  
Zongjie Hu ◽  
Jun Deng ◽  
Zhijun Wu ◽  
...  
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Low Pressure ◽  
Fuel Economy Improvement

Fuel Economy Improvement Potential of a PFI Gasoline Engine Using VVT/VCR

2004 ◽  
Author(s):  
Frank M. Washko ◽  
Ming-Chia Lai
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Fuel Efficiency ◽  
Operating Efficiency ◽  
Powertrain System ◽  
Improvement Potential ◽  
Fuel Economy Improvement ◽  
The Many ◽  
System Variables ◽  
Variable Valve

It is desired to optimize a spark ignition PFI (port fuel injected) engine for various regimes within the operating ranges of a vehicle. The goal of this work is to identify the set of technologies that complement each other and offer the optimum performance and fuel economy. For an ideal powertrain system, the engine should be optimized for best fuel economy during the typical drive cycles and best performance during high load acceleration. A typical PFI 1.8L four-cylinder engine is baselined at cycle representative speed/load points. The engine is supercharged and intercooled to later quantify the efficiency benefits from replacing a larger engine with a smaller boosted engine that offers similar performance. Then the effects of different operating regimes and the effect of different proposed technologies are studied. The fuel economy enablers considered include variable valve timing (VVT) and variable compression ratios (VCR). The effects of VVT was studied to see which valve event scenarios afford the best operating efficiency and fuel economy during part load operation. VVT can also be a source of performance improvement if implemented appropriately. VCR operation is studied to see if the efficiency gains from VCR are additive with VVT or if they overlap to some degree. Typically, the fuel efficiency potential of a production engine is limited by spark knock. The engine studied here uses the geometrical and virtual compression ratio reductions offered by the VVT and VCR systems to give knock limit relief and allows the knock-limited BMEP curve to be pushed up. The results showed that the fuel economy gain with the above mentioned technologies is somewhat additive throughout the typical driving cycle but is highly dependent on proper optimization of the many system variables.

Applications of VVT and VCR on Fuel Economy Improvement Based Engine Electronic Control

2004 ◽  
Author(s):  
Zhengmao Ye ◽  
Ming-Chia Lai
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Performance And Emission ◽  
Fuel Economy Improvement ◽  
Operating Regions ◽  
Economy Benefit ◽  
Variable Valve ◽  
Maximal Benefit

Variable valve timing (VVT) and variable compression ratio (VCR) are two technologies to obtain fuel economy benefit. On the other hand, there is a tradeoff among fuel economy, engine performance and emission levels. Advantages of two technologies vary a lot on different engine operating regions. Recently some experiments are conducted on a Port Fuel Injection (PFI) engine in a city drive cycle to investigate the fuel economy impact from VVT, VCR and the technology integration. The testing results show clearly that the synergy of two technologies has further improved the fuel economy, while suitable operating regions need to be determined where the maximal benefit can be achieved. A typical 1.8L four-cylinder gasoline engine is used for experiments using VVT and VCR technologies for fuel economy improvement. The objective is to create a synergy scheme for the optimal fuel economy performance. The supercharged testing engine with VVT and VCR can implement similar performance to that of a larger replacement engine. The fuel economy optimization problem is simply converted into searching for the lowest engine power output region with respect to the same fuel economy improvement level. These optimal points are useful to determine potential best fuel economy operating regions whether VVT and VCR should be implemented individually or combined together.

scholarly journals Study of the Miller Cycle on a Turbocharged DI Gasoline Engine Regarding Fuel Economy Improvement at Part Load

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1500 ◽  
Author(s):  
Xuewei Pan ◽  
Yinghua Zhao ◽  
Diming Lou ◽  
Liang Fang
Keyword(s):  
Fuel Economy ◽  
Thermal Efficiency ◽  
Gasoline Engine ◽  
Bench Test ◽  
Miller Cycle ◽  
Valve Timing ◽  
Brake Thermal Efficiency ◽  
Part Load ◽  
Brake Mean Effective Pressure ◽  
Fuel Economy Improvement

This contribution is focused on the fuel economy improvement of the Miller cycle under part-load characteristics on a supercharged DI (Direct Injection) gasoline engine. Firstly, based on the engine bench test, the effects with the Miller cycle application under 3000 rpm were studied. The results show that the Miller cycle has different extents of improvement on pumping loss, combustion and friction loss. For low, medium and high loads, the brake thermal efficiency of the baseline engine is increased by 2.8%, 2.5% and 2.6%, respectively. Besides, the baseline variable valve timing (VVT) is optimized by the test. Subsequently, the 1D CFD (Computational Fluid Dynamics) model of the Miller cycle engine after the test optimization at the working condition of 3000 rpm and BMEP (Brake Mean Effective Pressure) = 10 bar was established, and the influence of the combined change of intake and exhaust valve timing on Miller cycle was studied by simulation. The results show that as the effect of the Miller cycle deepens, the engine’s knocking tendency decreases, so the ignition timing can be further advanced, and the economy of the engine can be improved. Compared with the brake thermal efficiency of the baseline engine, the final result after simulation optimization is increased from 34.6% to 35.6%, which is an improvement of 2.9%.

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