Energy Availability Study for a Regenerative Hydraulically Assisted Turbocharger

Author(s):  
Tao Zeng ◽  
Yifan Men ◽  
Devesh Upadhyay ◽  
Guoming Zhu

Engine downsizing and down-speeding are essential to meet future US fuel economy mandates. While turbocharging has been a critical enabler for downsizing, transient boost response performance remains a concern even with variable geometry turbochargers. This slow build-up of boost and hence torque is commonly referred to as turbo-lag. Mitigation of turbo-lag has, therefore, remained an important objective of turbocharger performance enhancement research. A regenerative, hydraulically assisted turbocharger is one such enhanced turbocharging system that is able regulate the turbocharger speed independent of the available engine exhaust energy. With external power available on the turbocharger shaft, the engine performance and emissions can be managed during both transient and steady-state operations. The key to fully utilizing the ability of such an assisted turbocharger depends on the energy recovered from turbocharger shaft and/or vehicle driveline. Energy available from the turbocharger shaft is dependent on the engine exhaust gas energy. Energy recovered from the driveline depends on vehicle braking energy. A previously developed high-fidelity 1-D simulation of a diesel engine with a regenerative-hydraulically assisted turbocharger is used to investigate the energy availability for a medium duty diesel engine over standard driving cycles. The study shows that the energy recovery from turbocharger shaft is limited and driveline energy recovery is necessary for achieving fuel economy benefits on the order of 4%.

Author(s):  
G Fernandes ◽  
J Fuschetto ◽  
Z Filipi ◽  
D Assanis ◽  
H McKee

Investigating the impact of jet fuel on diesel engine performance and emissions is very important for military vehicles, due to the US Army Single Fuel Forward Policy mandating that deployed vehicles must refuel with aviation fuel JP-8. There is a known torque and fuel economy penalty associated with the operation of a diesel engine with JP-8 fuel, due to its lower density and viscosity. On the other hand, a few experimental studies have suggested that kerosene-based fuels have the potential for lowering exhaust emissions, especially particulate matter, compared to diesel fuel #2 (DF-2). However, studies so far have typically focused on quantifying the effects of simply replacing the regular DF-2 with JP-8, rather than fully investigating the reasons behind the observed differences. This research evaluates the effect of using JP-8 fuel in a heavy-duty diesel engine on fuel injection, combustion, performance, and emissions, and subsequently utilizes the obtained insight to propose changes to the engine calibration to mitigate the impact of the trade-offs. Experiments were carried out on a Detroit Diesel Corporation (DDC) S60 engine outfitted with exhaust gas recirculation (EGR). The results indicate that torque and fuel economy of diesel fuel can be matched, without smoke or NO x penalty, by increasing the duration of injection to compensate for the lower fuel density. The lower cetane number of JP-8 caused an increased ignition delay and increased premixed combustion, and their cumulative effect led to relatively unchanged combustion phasing. Under almost all conditions, JP-8 led to lower NO x and particulate matter (PM) emissions and shifted the NO x-PM trade-off favourably.


Fuel ◽  
2021 ◽  
Vol 302 ◽  
pp. 121097
Author(s):  
M. Mourad ◽  
Khaled R.M. Mahmoud ◽  
El-Sadek H. NourEldeen

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1612
Author(s):  
Federico Millo ◽  
Andrea Piano ◽  
Benedetta Peiretti Paradisi ◽  
Mario Rocco Marzano ◽  
Andrea Bianco ◽  
...  

In this paper, an integrated and automated methodology for the coupling between 1D- and 3D-CFD simulation codes is presented, which has been developed to support the design and calibration of new diesel engines. The aim of the proposed methodology is to couple 1D engine models, which may be available in the early stage engine development phases, with 3D predictive combustion simulations, in order to obtain reliable estimates of engine performance and emissions for newly designed automotive diesel engines. The coupling procedure features simulations performed in 1D-CFD by means of GT-SUITE and in 3D-CFD by means of Converge, executed within a specifically designed calculation methodology. An assessment of the coupling procedure has been performed by comparing its results with experimental data acquired on an automotive diesel engine, considering different working points, including both part load and full load conditions. Different multiple injection schedules have been evaluated for part-load operation, including pre and post injections. The proposed methodology, featuring detailed 3D chemistry modeling, was proven to be capable assessing pollutant formation properly, specifically to estimate NOx concentrations. Soot formation trends were also well-matched for most of the explored working points. The proposed procedure can therefore be considered as a suitable methodology to support the design and calibration of new diesel engines, due to its ability to provide reliable engine performance and emissions estimations from the early stage of a new engine development.


Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4023 ◽  
Author(s):  
Stefano d’Ambrosio ◽  
Alessandro Ferrari ◽  
Alessandro Mancarella ◽  
Salvatore Mancò ◽  
Antonio Mittica

An experimental investigation has been carried out to compare the performance and emissions of a low-compression-ratio Euro 5 diesel engine featuring high EGR rates, equipped with different injector technologies, i.e., solenoid, indirect-acting, and direct-acting piezoelectric. The comparisons, performed with reference to a state-of-the-art double fuel injection calibration, i.e., pilot-Main (pM), are presented in terms of engine-out exhaust emissions, combustion noise (CN), and fuel consumption, at low–medium engine speeds and loads. The differences in engine performance and emissions of the solenoidal, indirect-acting, and direct-acting piezoelectric injector setups have been found on the basis of experimental results to mainly depend on the specific features of their hydraulic circuits rather than on the considered injector driving system.


Sign in / Sign up

Export Citation Format

Share Document