EGR Systems Evaluation in Turbocharged Engines

Zhong, Lurun; Musial, Marc; Reese, Ronald; Black, Greg

doi:10.4271/2013-01-0936

Cited by 21 publications

(10 citation statements)

References 9 publications

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“…These results are within the results found by Alger et al [12], Cairns et al [9] and Zhong et al [14] in their research works. Figure 11a confirm how a sharp fuel consumption reduction was achieved by introducing 4% of EGR due to the fuel enrichment elimination, maintaining the exhaust gas temperature at almost the same value as the reference operating conditions but operating in stoichiometric conditions.…”

Section: Combustion and Engine Performancesupporting

confidence: 82%

“…Alger et al [12] reported the synergy between cooled EGR and GDI technologies obtaining reduction in fuel consumption of 4% in low and partial load primary through the reduction in pumping losses and 15%-20% at high load due to the improvement of combustion phasing, which is the time where the combustion process takes place in the engine cycle, and fuel enrichment elimination. Cairns et al [13] evaluated different cooled EGR loop configurations and their advantages and disadvantages, and Zhong et al [14] also discussed about different cooled EGR systems in a turbocharged SI engine. They found that the LP EGR system was the best configuration to ensure EGR operation in the entire engine operating range in order to minimize fuel consumption and exhaust gas emissions.…”

Section: Introductionmentioning

confidence: 99%

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Influence of a low pressure EGR loop on a gasoline turbocharged direct injection engine

Luján

Climent

Novella

et al. 2015

Applied Thermal Engineering

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This paper presents an experimental study of a low pressure EGR loop on a spark ignition (SI) Gasoline Turbocharged Direct Injection (GTDI) engine that will improve the understanding on the advantages and disadvantages of this strategy. Two steady engine operating conditions were investigated, 10 bar and 17 bar at 2000 rpm. At partial load conditions a combustion, performance, air management and exhaust gas emissions study was performed in order to analyses the EGR effect on the GTDI engine. The main advantages found were the reduction in fuel consumption due to the better combustion phasing, and the reduction in pumping losses and heat losses through the cylinder walls. A reduction on NOx, CO and soot was also observed when introducing EGR at these operating conditions. The main disadvantage found was the water condensation after the intercooler. At high load conditions similar analysis and conclusions to the partial load conditions are obtained. The EGR also allowed the combustion to be phased in a more efficient angle by reducing the risk of knocking, which helped reduce the exhaust gas temperature, despite the elimination of the fuel enrichment strategy. A reduction on CO and soot raw emissions was also observed when introducing EGR, as observed at partial load conditions, but a high reduction in NOx, CO, HC and soot emissions was observed after the catalyst since the fuel enrichment strategy is eliminated when cooled EGR is introduced. The main disadvantage found was the turbocharger limitation since higher compression ratio is required in order to keep the same air mass flow as the reference conditions without EGR. The original turbocharger is not designed to provide this higher compression ratio at low engine speed and high load. Results confirm how introducing EGR is a suitable strategy to control knocking and reduce simultaneously exhaust gas temperature and fuel consumption, but the disadvantages found in this investigation must be solved to assure its feasibility as a powerful technology to be implemented in future SI engines.

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Section: Combustion and Engine Performancesupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Influence of a low pressure EGR loop on a gasoline turbocharged direct injection engine

Luján

Climent

Novella

et al. 2015

Applied Thermal Engineering

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“…A large number of studies have assessed the potential of EGR in each of these architectures, [6][7][8][9][10][11][12][13][14][15][16][17][18][19] with some researchers advocating the combination of both high pressure and low pressure EGR architectures to allow full map operation of the EGR system without the obstacles associated with each individual architecture. 4 Additional factors in the design of EGR systems include the potential for condensate to damage the compressor in LP architectures, and additional demands that cooled EGR can place on vehicle cooling systems.…”

Section: Egr Architecturesmentioning

confidence: 99%

A comparative study into the effects of pre and post catalyst exhaust gas recirculation on the onset of knock

Parsons

Orchard

Evans

et al. 2020

International Journal of Engine Research

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Exhaust gas recirculation (EGR) is proven as a valuable technology for controlling knock whilst maintaining lambda one operation, and is also capable of providing efficiency gains at low load. Despite this few studies in the literature address the question of EGR composition effects, namely whether the EGR gas is sourced from before or after the catalyst, and this remains an area which is often overlooked whilst investigating EGR performance. This paper demonstrates a novel method combining experiment air-path emulation and in-depth data processes to compare the effect of EGR catalysis on the angle of knock onset in a 1L GDI engine. Since initial temperature and pressure have a significant impact on knocking behaviour, an artificial boosting rig replaced the turbomachinery. This enabled fine control over the engine boundary conditions to ensure parity between the catalysed and un-catalysed cases. To overcome the difficulty of comparing stochastic phenomena in an inherently variable dataset, a pairing method was combined with Shahlari and Ghandhi’s angle of knock onset determination method to assess the effects of EGR composition on knock onset for EGR rates ranging from 9% to 18%. The air path emulation system stabilised the engine combustion to provide a suitably rich dataset for analysing knock using the pairing method. Catalysed EGR improved the mean knock onset angle by 0.55 CAD, but due to the inherent variability in cylinder pressure data this only equated to a 58.3% chance of a later knock onset angle for catalysed EGR in any given pair of comparative cycles.

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“…This indicates that a LPL EGR system with higher TTE gives lower expansion ratio than a HPL EGR system with low TTE. [8] It focuses on allowing an engine to run with a LPL EGR system at lower engine speeds, and then switch to a HPL EGR system at engine speeds when the matching point is farther away from the higher efficiency area. For improving engine transient response, this proposed concept relatively enlarges the high efficiency area of a given turbocharger and also brings about the possibility for turbocharger downsizing.…”

Section: Dual Loop Egr Systemsmentioning

confidence: 99%