Variable Valve Actuation Systems for Homogeneous Diesel Combustion: How Interesting are They?

Walter, Bruno; Pacaud, P.; Gatellier, B.

doi:10.2516/ogst:2008004

Cited by 13 publications

(15 citation statements)

References 14 publications

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“…In their experimental work, He et al [12] suggest that the reduction in soot emissions achieved using LIVC is attributable to the extended ignition delay allowing greater time for mixing to reduce local fuel-rich regions. The results of Walter et al [16] are consistent with this interpretation. They also noted that lower in-cylinder temperatures reduced the level of EGR required to meet a target value of NO x but increased HC and CO emissions.…”

Section: Introductionsupporting

confidence: 86%

The effects of early inlet valve closing and cylinder disablement on fuel economy and emissions of a direct injection diesel engine

Zammit

McGhee

Shayler

et al. 2015

Energy

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a b s t r a c tThe influence of EIVC (early inlet valve closure) on emissions, fuel economy and exhaust gas temperature of a turbocharged, 4 cylinder common rail direct injection diesel engine has been investigated and compared with the influence of deactivating two cylinders. IVC (inlet valve closing) timings were set at up to 60 CA (crank angle) degrees earlier than the production setting of 37 ABDC for the engine. At the earliest timing, effective compression ratio was reduced from 15.2:1 to 13.7:1. The effects on emissions were significant only for EIVC settings at least 40 CA degrees earlier than the production setting, and were sensitive to engine load. At 2 bar BMEP (brake mean effective pressure) and fixed levels of NO x , soot emissions were reduced but CO (carbon monoxide) and HC (hydrocarbon) increased unless fuel rail pressure was reduced. With increasing load, soot reduction diminished and was negligible at 6 bar BMEP; CO and HC emissions deteriorated further. At all conditions, EIVC raised exhaust gas temperature by >50 C; the effect on fuel economy was negligible or a fuel economy penalty. Comparisons indicate cylinder deactivation is the more effective strategy for reducing engine-out emissions of HC and CO and raising exhaust gas temperature under light load operating conditions.

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Section: Introductionsupporting

confidence: 86%

The effects of early inlet valve closing and cylinder disablement on fuel economy and emissions of a direct injection diesel engine

Zammit

McGhee

Shayler

et al. 2015

Energy

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“…The valves opening in the cylinder determine the amount of gas that may enter (intake valve) or exit (exhaust valve) to or from the combustion chamber [8]. It also determines the flow rate, and hence the pressure and temperature while combustion occurs.…”

Section: Valve Timing and Valve Liftmentioning

confidence: 99%

“…Negative valve overlapping (NVO) consists of closing both valves for a period of time [5][6][7][8]. Exhaust valve closes before piston reaches the TDC, and intake valve opens after piston moves beyond the TDC.…”

Section: Valve Overlappingmentioning

confidence: 99%

“…Research shows that the temperature of air is heated up by exhaust gas, which acts as a preheater before entering the combustion chamber at low speed. The effect is cancelled out at high speed and low load due to the decline in the temperature cycle, and hence no improvement is made [8]. Also, it affects significant improvement of performance such as NOx emission, engine break power, and fuel consumption.…”

Section: Late Intake Valve Closing On Diesel Enginementioning

confidence: 99%

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Comparison of Engine Simulation Software for Development of Control System

Chan

Ordys

Волков

et al. 2013

Modelling and Simulation in Engineering

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Most commonly used commercial engine simulation packages generate detailed estimation of the combustion and gas flow parameters. These parameters are required for advanced research on fluid flow and heat transfer and development of geometries of engine components. However, engine control involves different operating parameters. Various sensors are installed into the engine, the combustion performance is recorded, and data is sent to engine control unit (ECU). ECU computes the new set of parameters to make fine adjustments to actuators providing better engine performance. Such techniques include variable valve timing, variable ignition timing, variable air to fuel ratio, and variable compression ratio. In the present study, two of the commercial packages, Ricardo Wave and Lotus Engine Simulation, have been tested on the capabilities for engine control purposes. These packages are compared with an in-house developed package and with reference results available from the literature. Different numerical experiments have been carried out from which it can be concluded that all packages predict similar profiles of pressure and temperature in the engine cylinder. Moreover, those are in reasonable agreement with the reference results while in-house developed package is possible to run simulations with changing speed for engine control purpose.

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“…서 론 (1) . 신개념 연소 방식으로는 HCCI(Homogeneous charge compression ignition) (2) , PCCI(Partially premixed charge compression ignition) 등이 있다. PCCI 연소의 경우, 이른 시간 연료를 분사하여 공기와 연료가 혼합될 수 Table 2 와 같다.…”

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Performance Analysis of Variable Valve for Diesel Engine with Cam-in-Cam System

Jeong¹,

Park²,

Kim³

et al. 2017

Journal of ILASS-Korea

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In this study, the effects of intake valve closing timing by using Cam-in-Cam system on combustion and emission characteristics for diesel engine were investigated under GT-POWER simulation environment. As a result, it was found that volumetric efficiency and effective compression ratio were decreased as the intake valve closing(IVC) timing is retarded due to its backflow effect. Also, we found that in-cylinder pressure, heat release rate and NOx emission were decreased as IVC timing was retarded. These show that the LIVC(late intake valve closing) can be effective to control AFR and mixing rate in diffusion combustion of diesel engine.

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Variable Valve Actuation Systems for Homogeneous Diesel Combustion: How Interesting are They?

Cited by 13 publications

References 14 publications

The effects of early inlet valve closing and cylinder disablement on fuel economy and emissions of a direct injection diesel engine

The effects of early inlet valve closing and cylinder disablement on fuel economy and emissions of a direct injection diesel engine

Comparison of Engine Simulation Software for Development of Control System

Performance Analysis of Variable Valve for Diesel Engine with Cam-in-Cam System

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