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.

scholarly journals Numerical analyses of a hydraulic hybrid powertrain system for a transit bus

2020 ◽  
Vol 24 (1 Part A) ◽  
pp. 159-170
Author(s):  
Marko Kitanovic ◽  
Slobodan Popovic ◽  
Nenad Miljic ◽  
Predrag Mrdja
Keyword(s):  
Dynamic Programming ◽  
Fuel Economy ◽  
Model Parameters ◽  
Hybrid Powertrain ◽  
Hydraulic Hybrid ◽  
Powertrain System ◽  
Improvement Potential ◽  
Fuel Economy Improvement ◽  
Hydraulic Accumulator ◽  
Transit Bus

A dynamic programming optimization algorithm has been applied on a transit bus model in MATLAB in order to assess the fuel economy improvement potential by implementing a hydraulic hybrid powertrain system. The numerical model parameters have been calibrated using experimental data obtained on a Belgrade?s public transport bus. This experiment also provided the representative driving cycle on which to conduct simulation analyses. Various functional parameters of a hydraulic hybrid system have been evaluated for obtaining the best possible fuel economy. Dynamic programming optimization runs have been completed for various hydraulic accumulator sizes, preload values and accumulator foam quantities. It has been shown that a fuel economy improvement of 28% can be achieved by implementing such a system.

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.

Development Concept for Non Conventional Hybrid Engine

2010 ◽  
Author(s):  
Harsh Purohit ◽  
Ankit Shah ◽  
Nishant Parekh ◽  
Akash Pandey
Keyword(s):  
Fuel Economy ◽  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Combustion Engines ◽  
Common People ◽  
Advantages And Disadvantages ◽  
Compact Size ◽  
Hybrid Engines ◽  
Variable Valve

Environmental issues and the need for environment-friendly transport have always been a priority for the world due to ever increasing demand of modes of transport. So developing quick and eco friendly vehicle is the trend as of now with most manufacturers globally. There are numerous ways in which manufacturers have tackled these issues. Some of the common approaches undertaken are refinements of existing internal combustion engines. Like developing technologies such as direct injection, VVT (variable valve time), VTEC (variable valve time electronic lift), VGT (variable geometry turbines), reducing engine friction and weight, cam less engines, micro hybrids, etc But the best/optimum compromise between eco friendliness and urge to develop more power with good fuel economy and reduced emission is best met by the development of hybrid engines. Thermal and electric engines both have advantages and disadvantages that are often complementary. Combustion engines offer better range, power and ‘lunge’, but give out exhaust gas, although the current Euro IV norm place strict limits on these. Electric engines are zero-emission and offer very quick pick-up from a stopped position, but the batteries have low range and limited speed. So this complementation of both power trains is exploited in hybrid engines. Now conventional hybrids have many disadvantages such as being bulky with additional weight of battery packs and motors and other auxiliary transmission components, complex and dangerous electric systems, etc. So it is proposed to develop a non conventional hybrid engine which produces power at par with the conventional one and releases emission which is compatible with the stringent emission norms set for the conventional hybrids with considerably lucrative fuel economy comparable with the currently available hybrids in market and yet overcome the drawbacks of the conventional hybrid engines. Also the compact size of the hybrid engine that we propose makes it quite viable to fitted in small vehicles (like bikes, compact cars, etc) which further makes it a more promising technology that can be made available to common people across the globe and there by lead to a better transportation system for people of all class and need. The conceptualization basically includes modification of an inline twin cylinder or a v-twin 4-stroke gasoline engine as a preliminary step towards achieving the above proposed objectives.

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 Study with Energy Management of Heavy Duty Truck HEV for Long Haul Application

2015 ◽  
Author(s):  
Nobuhiro Kondo ◽  
Hideyuki Takahashi ◽  
Junichi Yamada ◽  
Keiki Tanabe ◽  
Takuya Kitasei ◽  
...  
Keyword(s):  
Energy Management ◽  
Fuel Economy ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Potential Study ◽  
Improvement Potential ◽  
Fuel Economy Improvement
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