scholarly journals Butanol-gasoline blend and exhaust gas recirculation, impact on GDI engine emissions

Fuel ◽  
2017 ◽  
Vol 208 ◽  
pp. 662-672 ◽  
Author(s):  
C. Hergueta ◽  
M. Bogarra ◽  
A. Tsolakis ◽  
K. Essa ◽  
J.M. Herreros
Keyword(s):  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Engine Emissions ◽  
Gdi Engine ◽  
Gas Recirculation

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

2020 ◽  
pp. 146808742096229
Author(s):  
Dominic Parsons ◽  
Simon Orchard ◽  
Nick Evans ◽  
Umud Ozturk ◽  
Richard Burke ◽  
...  
Keyword(s):  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Engine Combustion ◽  
Low Load ◽  
Fine Control ◽  
Novel Method ◽  
Gdi Engine ◽  
Stochastic Phenomena ◽  
Gas Recirculation ◽  
Onset Angle

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.

scholarly journals Low Temperature Combustion with Multiple Injection Strategies in Single Cylinder Diesel Engine

2020 ◽  
Vol 9 (7) ◽  
pp. 779-785
Keyword(s):  
Low Temperature ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Low Temperature Combustion ◽  
Multiple Injection ◽  
Engine Emissions ◽  
Multiple Injections ◽  
Temperature Combustion ◽  
Gas Recirculation ◽  
Injection Strategies

Low-temperature combustion(LTC) with multiple injection strategies is a recent trend for NOx and soot reduction in single-cylinder diesel engines. This paper presents a technical study of past research carried out on multiple injections, which are pilot I and pilot II injection before main injection, to decrease engine soot to meet emission legislation while upholding efficiency and decrease or eliminate exhaust after treatment. Previous research indicates that extending ignition lag to enhance the proper premixing, and controlling temperature of combustion to optimal level using Exhaust Gas Recirculation, have been accepted as an important aspect to attain low temperature combustion. In this paper, we first discuss the effect pilot I injection and pilot II injection strategy through varied injection quantity and time range. Thereafter, we briefly review how pilot II injection provides better results compared with the pilot I injection, which is by reason of better premixing, improves the turbulent effect and lowers the emission. Next, we provide a broad overview of the collected works on the effect of injection pressure, temperature and rate of exhaust gas recirculation on engine emissions. We conclude by identifying a few dependencies of engine parameters in low-temperature combustion by multiple injections so as to reduce the engine emissions.

scholarly journals Effect of LP-EGR on the Emission Characteristics of GDI Engine

Machines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Diming Lou ◽  
Guokang Lou ◽  
Bo Wang ◽  
Liang Fang ◽  
Yunhua Zhang
Keyword(s):  
High Speed ◽  
Load Condition ◽  
Exhaust Gas Recirculation ◽  
Gasoline Direct Injection ◽  
Emission Characteristic ◽  
Exhaust Gas ◽  
Particulate Emission ◽  
Gdi Engine ◽  
Gas Recirculation ◽  
Co Emission

Exhaust gas recirculation (EGR) can improve the fuel economy of gasoline direct-injection (GDI) engines, but at the same time it will have a significant impact on emissions. In this paper, the effects of low-pressure exhaust gas recirculation (LP-EGR) and its rate on the main gaseous and particulate emission characteristic of a GDI engine were investigated. The results showed that the particle size distribution of the GDI engine presented bimodal peaks in nucleation and accumulation mode, and the nucleation mode particles comprised the vast majority of the total particles. The effect of LP-EGR on emissions depended on the engine conditions. At low and medium speed, the particle emissions increased with the increase in the EGR rate, while at high speed, a reduction in the particle emission was observed. When the engine operated in full load condition, an increase in the EGR rate reduced the particle number (PN) concentration significantly, but increased the particle mass (PM) concentration. In terms of the gaseous emission, the EGR could reduce as much as 80% of the NOx emission; however, the total hydrocarbons (THC) emission presented an increased trend, and the maximum increase reached 23.5%. At low and medium loads, the EGR could reduce the CO emission, but at high load, the CO emission worsened with the EGR.

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