HCCI Operation of a Passenger Car DI Diesel Engine with an Adjustable Valve Train

Helmantel, Arjan; Denbratt, Ingemar

doi:10.4271/2006-01-0029

Cited by 24 publications

(11 citation statements)

References 14 publications

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“…Recently, Fuyuto et al 52 tested the potential of controlling the temperature stratification for diesel combustion using similar intake valve profiles to those shown in Figure 33(b) with a constant opening duration for two intake valves and retarded opening timing for one intake valve. Helmantel and Denbratt 9 evaluated the potential of retarding the phasing of the intake valve, while maintaining the opening duration for a diesel HCCI engine. By retarding the phasing of both intake valve lift profiles, as shown in Figure 33(b), Helmantel and Denbratt 9 found that closing intake valves during the beginning of the intake stroke contributes to pumping losses and, consequently, the increase of fuel consumption.…”

Section: Resultsmentioning

confidence: 99%

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Numerical investigation of the influence of intake valve lift profile on a diesel premixed charge compression ignition engine with a variable valve actuation system at moderate loads and speeds

Jia

Xie

Wang

2012

International Journal of Engine Research

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Variable valve actuation is attracting increasing attention for the control of diesel premixed charge compression ignition engines due to its fast-response characteristics. In this study, a three-dimensional computational fluid dynamics model, coupled with detailed chemical kinetics, is used to evaluate the influence of the intake valve lift profile on combustion and emissions of a diesel premixed charge compression ignition engine at moderate loads and speeds. The results indicate that, among all the tested variable valve actuation strategies, late intake valve closing shows the most potential for control of ignition timing and reduction of nitrogen oxide emissions, while maintaining low soot emissions and fuel consumption. A moderate decrease of intake valve lift is beneficial for the reduction of soot emissions without significant impacts on fuel consumption due to the enhanced intake flow. The enhancement of turbulence kinetic energy of the in-cylinder mixture is helpful for fuel/air mixing and soot reduction. However, the strategies for increasing turbulence kinetic energy by using intake valve reopening around the start of injection timing and one intake valve deactivation lead to deterioration in fuel efficiency due to the increased pumping work. In general, the increase of swirl ratio with various variable valve actuation strategies impedes the fuel/air mixing, resulting in rapid increases of soot emissions, and a lower swirl ratio is more beneficial for mixing and combustion in diesel premixed charge compression ignition engines with early injection timing.

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Section: Resultsmentioning

confidence: 99%

“…By using a fully adjustable hydraulic valve train, several valve timing strategies were tested by Helmantel and Denbratt 9 in a diesel HCCI engine. It was indicated that less EGR is required to maintain the ignition point around TDC as the late IVC strategy was employed.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation of the influence of intake valve lift profile on a diesel premixed charge compression ignition engine with a variable valve actuation system at moderate loads and speeds

Jia

Xie

Wang

2012

International Journal of Engine Research

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“…As a result, the effective compression ratio is reduced and peak compression pressures and temperatures are also lowered. LIVC has been shown to improve fuel efficiency by reducing pumping losses, [20][21][22][23] as well as reduce exhaust emissions. He et al 24 found that LIVC reduces approximately 25%-50% NOx emissions and more than 95% PM at some operating conditions on a diesel engine with a fully flexible valve actuation system.…”

Section: Introductionmentioning

confidence: 99%

Modeling and control of fuel distribution in a dual-fuel internal combustion engine leveraging late intake valve closings

Kassa

Hall

Ickes

et al. 2016

International Journal of Engine Research

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In internal combustion engines, cycle-to-cycle and cylinder-to-cylinder variations of the combustion process have been shown to negatively impact the fuel efficiency of the engine and lead to higher exhaust emissions. The combustion variations are generally tied to differences in the composition and condition of the trapped mass throughout each cycle and across individual cylinders. Thus, advanced engines featuring exhaust gas recirculation, flexible valve actuation systems, advanced fueling strategies, and turbocharging systems are prone to exhibit higher variations in the combustion process. In this study, the cylinder-to-cylinder variations of the combustion process in a dual-fuel internal combustion engine leveraging late intake valve closing are investigated and a model to predict and address one of the root causes for these variations across cylinders is developed. The study is conducted on an inline six-cylinder heavy-duty dual-fuel engine equipped with exhaust gas recirculation, a variable geometry turbocharger, and a fully flexible variable intake valve actuation system. The engine is operated with late intake valve closure timings in a dual-fuel combustion mode in which a high reactivity fuel is directly injected into the cylinders and a low reactivity fuel is port injected into the cylinders. The cylinder-to-cylinder variations observed in the study have been associated with the maldistribution of the port-injected fuel, which is exacerbated at late intake valve timings. The resulting difference in indicated mean effective pressure between the cylinders ranges from 9% at an intake valve closing of 570° after top dead center to 38% at an intake valve closing of 620° after top dead center and indicates an increasingly uneven fuel distribution. The study leverages both experimental and simulation studies to investigate the distribution of the port-injected fuel and its impact on cylinder-to-cylinder variation. The effects of intake valve closing as well as the impact of intake runner length on fuel distribution were quantitatively analyzed, and a model was developed that can be used to accurately predict the fuel distribution of the port-injected fuel at different operating conditions with an average estimation error of 1.5% in cylinder-specific fuel flow. A model-based control strategy is implemented to adjust the fueling at each port and shown to significantly reduce the cylinder-to-cylinder variations in fuel distribution.

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“…From the perspective of some practical approaches, the potential of variable-valve-timing technologies is being studied in the diesel engine field for emissions improvement. 7,13,14 The variable-valve-timing technologies have been broadly used in gasoline engines to improve the volumetric efficiency (the scavenging process) and to reduce the pumping loss, thus improving the overall engine fuel consumption and the performance. 1,15 However, variable valve trains are not yet in mass commercialization in diesel engines because they have a lower throttling loss and a better scavenging performance than those in gasoline engines do.…”

Section: Introductionmentioning

confidence: 99%

An investigation on the effects of late intake valve closing and exhaust gas recirculation in a single-cylinder research diesel engine in the low-load condition

Kim

Bae

2015

Proceedings of the Institution of Mechanical Engineers, Part D:

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The effects of late intake valve closing and exhaust gas recirculation on the emissions and the engine performance of a single-cylinder diesel research engine were observed. Two cam profiles (symmetric and asymmetric) were implemented using an offset angle at various intake valve closing timings to characterize the engine performance and the emissions. The injection timings were swept at every condition to evaluate the optimal operating conditions. The highest indicated mean effective pressure was observed once the combustion phasing was tuned to the optimum crank angle (in degrees) by varying the injection timing. The indicated mean effective pressure exhibited a slight penalty when both exhaust gas recirculation and late intake valve closing were used in comparison with the base intake valve closing timing with no exhaust gas recirculation. However, an appropriate combination of the exhaust gas recirculation with late intake valve closing was effective in reducing the nitrogen oxide emissions owing to the decreased in-cylinder temperature. The prolonged ignition delay with exhaust gas recirculation and late intake valve closing also contributed to the improvement in the nitrogen oxides–smoke trade-off relationship. The potential for further reduction in the smoke emissions with the asymmetric cam profile was observed. An increase in the in-cylinder swirl motion was expected, which enhanced the air–fuel mixing process.

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HCCI Operation of a Passenger Car DI Diesel Engine with an Adjustable Valve Train

Cited by 24 publications

References 14 publications

Numerical investigation of the influence of intake valve lift profile on a diesel premixed charge compression ignition engine with a variable valve actuation system at moderate loads and speeds

Numerical investigation of the influence of intake valve lift profile on a diesel premixed charge compression ignition engine with a variable valve actuation system at moderate loads and speeds

Modeling and control of fuel distribution in a dual-fuel internal combustion engine leveraging late intake valve closings

An investigation on the effects of late intake valve closing and exhaust gas recirculation in a single-cylinder research diesel engine in the low-load condition

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