scholarly journals Study on Valve Strategy and Fuel Benefits of Skip Fire Based on Electromagnetic Valve Train

2018 ◽  
Vol 202 ◽  
pp. 02003
Author(s):  
Maoyang Hu ◽  
Siqin Chang

Cylinder deactivation (CDA) is a fuel consumption reduction technology for gasoline engines. Skip fire is a new type of CDA because the load and the density of firing cylinder are in proportion to the torque demand. However, it is difficult to realize because valves need to be switched between valve deactivation and normal operation stroke by stroke. The Electromagnetic valve train (EMVT) provides a fully flexible control method to achieve skip fire. In the paper, a new skip fire strategy based on electromagnetic intake valve train (EMIV) is proposed. Then, the oxygen concentration of the exhaust pipe, energy losses, in-cylinder pressure of the skipped cycle and exhaust gas recirculation (EGR) rate of the firing cycle are studied by the 1D simulation in GT-Power. The results shows the majority of gas sucked into the skipped cylinder is exhaust gas by reasonable control of IVO and IVC, and the exhaust oxygen-rich can be avoided. Meanwhile, EGR rate of the firing cylinder and energy losses of the skipped cylinder are maintained at lower level. At the conditions of 1200 and 1600 rpm, fuel economy has been improved respectively 8.1%-16.6% and 6.4%-14.6% when the brake mean effective pressure (BMEP) ranges from 0.4MPa to 0.2MPa.

2018 ◽  
Vol 8 (11) ◽  
pp. 2096 ◽  
Author(s):  
Maoyang Hu ◽  
Siqin Chang ◽  
Yaxuan Xu ◽  
Liang Liu

The camless electromagnetic valve train (EMVT), as a fully flexible variable valve train, has enormous potential for improving engine performances. In this paper, a new valve strategy based on the electromagnetic intake valve train (EMIV) is proposed to achieve variable cylinder deactivation (VCD) on a four-cylinder gasoline engine. The 1D engine model was constructed in GT-Power according to test data. In order to analyze the VCD operation with the proposed valve strategy, the 1D model was validated using a 3D code. The effects of the proposed valve strategy were investigated from the perspective of energy loss of the transition period, the mass fraction of oxygen in the exhaust pipe, and the minimum in-cylinder pressure of the active cycle. On the premise of avoiding high exhaust oxygen and oil suction, the intake valve timing can be determined with the variation features of energy losses. It was found that at 1200 and 1600 rpm, fuel economy was improved by 12.5–16.6% and 9.7–14.6%, respectively, under VCD in conjunction with the early intake valve closing (EIVC) strategy when the brake mean effective pressure (BMEP) ranged from 0.3 MPa to 0.2 MPa.


2020 ◽  
Vol 171 ◽  
pp. 115097 ◽  
Author(s):  
Xinyu Fan ◽  
Jianguo Dai ◽  
Jiayu Lu ◽  
Huaping Xu ◽  
Cao Tan

2019 ◽  
Vol 21 (7) ◽  
pp. 1134-1146
Author(s):  
Kalen R Vos ◽  
Gregory M Shaver ◽  
Mrunal C Joshi ◽  
James McCarthy

Aftertreatment thermal management is critical for regulating emissions in modern diesel engines. Elevated engine-out temperatures and mass flows are effective at increasing the temperature of an aftertreatment system to enable efficient emission reduction. In this effort, experiments and analysis demonstrated that increasing the idle speed, while maintaining the same idle load, enables improved aftertreatment “warm-up” performance with engine-out NOx and particulate matter levels no higher than a state-of-the-art thermal calibration at conventional idle operation (800 rpm and 1.3 bar brake mean effective pressure). Elevated idle speeds of 1000 and 1200 rpm, compared to conventional idle at 800 rpm, realized 31%–51% increase in exhaust flow and 25 °C–40 °C increase in engine-out temperature, respectively. This study also demonstrated additional engine-out temperature benefits at all three idle speeds considered (800, 1000, and 1200 rpm, without compromising the exhaust flow rates or emissions, by modulating the exhaust valve opening timing. Early exhaust valve opening realizes up to ~51% increase in exhaust flow and 50 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder via an early blowdown of the exhaust gas. This early blowdown of exhaust gas also reduces the time available for particulate matter oxidization, effectively limiting the ability to elevate engine-out temperatures for the early exhaust valve opening strategy. Alternatively, late exhaust valve opening realizes up to ~51% increase in exhaust flow and 91 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder to pump in-cylinder gases across a smaller exhaust valve opening. In short, this study demonstrates how increased idle speeds, and exhaust valve opening modulation, individually or combined, can be used to significantly increase the “warm-up” rate of an aftertreatment system.


2018 ◽  
Vol 129 ◽  
pp. 833-840 ◽  
Author(s):  
Maoyang Hu ◽  
Siqin Chang ◽  
Liang Liu ◽  
Yaxuan Xu ◽  
Jiangtao Xu

2013 ◽  
Vol 738 ◽  
pp. 272-275
Author(s):  
Dun Chen Lan

In the field of mechanical automation, intelligent industrial robot technology is an important branch in the research field of robot; it is always the hot spots of the world robot research, and it being used to get the application in the industry today. Robot experiment platform of PLC and motor control technology, it based on the control method used by the robot control system improvements to make it more perfect run more precise, reasonable. In the same time, the man-machine interface state run monitoring, to ensure the normal operation of the system. Improved control method of the improvement of the work efficiency, reduce the work of the workers a duplication degree have a significant effect, and the system control at the scene, especially PLC control has excellent control function and good cost performance .


2004 ◽  
Author(s):  
Christoph Hartwig ◽  
Olaf Josef ◽  
Klaus Gebauer

2010 ◽  
Vol 46 (3) ◽  
pp. 1166-1174 ◽  
Author(s):  
Yoshio Yoshioka ◽  
Hiroaki Kondo ◽  
Yasuharu Tabata ◽  
Hayato Hatakenaka ◽  
Katsushi Nakada

2011 ◽  
Vol 317-319 ◽  
pp. 1999-2006
Author(s):  
Yu Wan ◽  
Ai Min Du ◽  
Da Shao ◽  
Guo Qiang Li

According to the boost mathematical model verified by experiments, the valve train of traditional gasoline engine is optimized and improved to achieve extended expansion cycle. The simulation results of extended expansion gasoline engine shows that the extended expansion gasoline engine has a better economic performance, compared to traditional gasoline engines. The average brake special fuel consumption (BSFC) can reduce 22.78 g / kW•h by LIVC, but the negative impacts of extended expansion gasoline engine restrict the potential of extended expansion gasoline engine. This paper analyzes the extended expansion gasoline engine performance under the influence of LIVC, discusses the way to further improve extended expansion gasoline engine performance.


2021 ◽  
Author(s):  
Dominik Appel ◽  
Fabian Hagen ◽  
Uwe Wagner ◽  
Thomas Koch ◽  
Henning Bockhorn ◽  
...  

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