Engine displacement modularity for enhancing automotive s.i. engines efficiency at part load

Millo, Federico; Mirzaeian, Mohsen; Luisi, Sabino; Doria, Vittorio; Stroppiana, Andrea

doi:10.1016/j.fuel.2016.04.049

Cited by 21 publications

(12 citation statements)

References 6 publications

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“…The additional fuel is injected to keep the average air-fuel ratio at the stoichiometric value, which depresses fuel economy achieved by skip fire. So valve strategy needs to ensure that the oxygen concentration in exhaust pipe had better be less than 1% according to Millo's study [10]. Thirdly, the requirement of avoiding interference between valve and piston is not necessary for an engine because of different geometry sizes.…”

Section: Valve Strategy and Model Details 21 Valve Strategymentioning

confidence: 99%

“…But the minimum in-cylinder pressure of skipped cycles is about 0.006MPa that may lead to oil being drawn in cylinder, even if the decrease of trapped exhaust gas is beneficial to reduce the air spring losses [9]. Millo et al [10] proposed a fixed CDA mode strategy based on MultiAir system. They studied the pumping losses and oxygen concentration in the exhaust line, and got the optimal intake valve closing timing.…”

Section: Introductionmentioning

confidence: 99%

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

Chang

2018

MATEC Web Conf.

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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.

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Section: Valve Strategy and Model Details 21 Valve Strategymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

Chang

2018

MATEC Web Conf.

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“…Many studies have been reported addressing the impact of cylinder deactivation in terms of efficiency and emissions. Almost all of these found that cylinder deactivation significantly reduced fuel consumption under part load operation [2][3][4][5][6][7][8][9] . The improvement in fuel economy for vehicle running under driving conditions was also examined by Abas et.…”

Section: Introductionmentioning

confidence: 99%

Impact and observations of cylinder deactivation and reactivation in a downsized gasoline turbocharged direct injection engine

Parker

Jiang

Butcher

et al. 2019

International Journal of Engine Research

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Cylinder deactivation, sometimes referred to as variable displacement engine technology, is a method being employed in state-of-the-art reciprocating engines to improve fuel economy. The approach involves disabling the valve actuation of one or more cylinders to deactivate them, thus forcing the engine to operate at a higher specific load across the remaining cylinders to produce the torque demanded. Operating at such a point with an increased throttle opening reduces the engine’s pumping losses and hence reduces fuel consumption. In this work, the spray morphology, combustion and emissions of a three-cylinder downsized gasoline turbocharged direct injection engine with variable displacement engine capability on one cylinder were studied. This investigation allowed the interaction between the fuel spray, engine performance and emissions immediately following the reactivation of the deactivated cylinder to be better understood. Three operation modes were examined which included running the engine at full displacement, at the reduced displacement and at full displacement with increased indicated mean effective pressure, matching that of the reduced displacement mode. The study showed that cylinder deactivation significantly reduced specific fuel consumption at the conditions tested in comparison to full displacement operation. It was also found that when running the engine at full displacement but with the reduced displacement–level indicated mean effective pressure, the specific fuel consumption was greater than for reduced displacement operation. In addition, it was observed that particulate number emissions increase transiently during the deactivation period due to the disturbances to the fuelling control caused by displacement transitions. Improved fuelling control, refinement of the engine calibration during reduced displacement operation or a gasoline particulate filter could be used to manage this particulate number level.

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“…Hybrid electric vehicles combine a traditional internal combustion engine with a motor and hydraulic pump, which reduces harmful emissions of the internal combustion engine and effectively improves fuel economy. As one of the main components of hybrid electric vehicles, internal combustion engines still have an irreplaceable position [1][2][3][4]. Thus, the internal combustion engine will still comprise a large proportion of vehicles in the future.…”

Section: Introductionmentioning

confidence: 99%

Design of an Electromagnetic Variable Valve Train with a Magnetorheological Buffer

et al. 2019

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In this paper, an electromagnetic variable valve train with a magnetorheological buffer (EMVT with MR buffer) is proposed. This system is mainly composed of an electromagnetic linear actuator (EMLA) and a magnetorheological buffer (MR buffer). The valves of an internal combustion engine are driven by the EMLA directly to open and close, which can adjust the valve lift and phase angle of the engine. At the same time, MR buffer can reduce the seat velocity of the valve and realize the seat buffer of the electromagnetic variable valve. In this paper, the overall design scheme of the system is proposed and the structure design, finite element simulation of the EMLA, and the MR buffer are carried out. The electromagnetic force characteristics of the EMLA and buffer force of the MR buffer are measured, and the seat buffering performance is verified as well. Experiments and simulation results show that the electromagnetic force of the EMLA can reach 320.3 N when the maximum coil current is 40 A. When the current of the buffer coil is 2.5 A and the piston’s motion frequency is 5 Hz, the buffering force can reach 35 N. At the same time, a soft landing can be realized when the valve is seated.

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Engine displacement modularity for enhancing automotive s.i. engines efficiency at part load

Cited by 21 publications

References 6 publications

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

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

Impact and observations of cylinder deactivation and reactivation in a downsized gasoline turbocharged direct injection engine

Design of an Electromagnetic Variable Valve Train with a Magnetorheological Buffer

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