A numerical study of the effects of boost pressure and exhaust gas recirculation ratio on the combustion process and exhaust emissions in a diesel engine

2007 ◽  
Vol 8 (2) ◽  
pp. 147-162 ◽  
Author(s):  
Sang-Kyu Kim ◽  
Tomoyuki Wakisaka ◽  
Yujo Aoyagi
Keyword(s):  
Diesel Engine ◽  
Numerical Study ◽  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
Exhaust Emissions ◽  
Boost Pressure ◽  
Exhaust Gas ◽  
Gas Recirculation

Diesel Engine Intake Condition Control-Oriented Models for Active Fuel Injection Profile Control

2011 ◽  
Author(s):  
Fengjun Yan ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
High Fidelity ◽  
Exhaust Gas ◽  
Engine Model ◽  
Profile Control ◽  
Gas Recirculation

Fueling control in Diesel engines is not only of significance to the combustion process in one particular cycle, but also influences the subsequent dynamics of air-path loop and combustion events, particularly when exhaust gas recirculation (EGR) is employed. To better reveal such inherently interactive relations, this paper presents a physics-based, control-oriented model describing the dynamics of the intake conditions with fuel injection profile being its input for Diesel engines equipped with EGR and turbocharging systems. The effectiveness of this model is validated by comparing the predictive results with those produced by a high-fidelity 1-D computational GT-Power engine model.

The effects of exhaust gas recirculation on diesel combustion and emissions

2000 ◽  
Vol 1 (1) ◽  
pp. 107-126 ◽  
Author(s):  
N Ladommatos ◽  
S Abdelhalim ◽  
H Zhao
Keyword(s):  
Carbon Dioxide ◽  
Heat Capacity ◽  
Diesel Engine ◽  
Combustion Process ◽  
Exhaust Gas Recirculation ◽  
Particulate Emissions ◽  
Exhaust Gas ◽  
Particulate Emission ◽  
Gas Recirculation ◽  
Charge Temperature

An investigation was conducted with the aim of identifying and quantifying the effects of exhaust gas recirculation (EGR) on diesel engine combustion and exhaust emissions. Five effects of EGR were identified and investigated experimentally: the reduction in oxygen supply to the engine, participation in the combustion process of carbon dioxide and water vapour present in the EGR, increase in the specific heat capacity of the engine inlet charge, increased inlet charge temperature and reduction in the inlet charge mass flowrate arising from the use of hot EGR. The experimental methodology developed allowed each one of these effects to be investigated and quantified separately. The investigation was carried out on a high-speed, direct injection diesel engine, running at an intermediate speed and load. A limited number of tests were also conducted in an optically accessible diesel engine, which established the effects of EGR on local flame temperature. Finally, tests were conducted with simulated EGR being used additionally to the engine air supply. This contrasts with the conventional use of EGR, whereby EGR replaces some of the air supplied to the engine. It was found that the first effect of EGR (reduction in the oxygen flowrate to the engine) was substantial and resulted in very large reductions in exhaust NOx at the expense of higher particulate emissions. The second and third effects (participation of carbon dioxide and water vapour in the combustion process and increase in the charge specific heat capacity) were almost insignificant. The fourth effect (higher inlet charge temperature) increased both exhaust NOx and particulate emissions. The fifth effect (reduction in the inlet charge due to thermal throttling) reduced NOx but raised particulate emission. Finally, when EGR was used additionally to the inlet air charge (rather than displacing air), substantial reductions in NOx were recorded with little increase in particulate emission.

The effects of carbon dioxide in exhaust gas recirculation on diesel engine emissions

1998 ◽  
Vol 212 (1) ◽  
pp. 25-42 ◽  
Author(s):  
N Ladommatos ◽  
S M Adelhalim ◽  
H Zhao ◽  
Z Hu
Keyword(s):  
Carbon Dioxide ◽  
Diesel Engine ◽  
High Speed ◽  
Combustion Process ◽  
Dilution Effect ◽  
Exhaust Gas Recirculation ◽  
Chemical Effect ◽  
Particulate Emissions ◽  
Exhaust Gas ◽  
Gas Recirculation

The investigation was conducted on a high-speed direct injection diesel engine and was concerned with the effects of exhaust gas recirculation (EGR) on diesel engine combustion and emissions. In particular, the effects of carbon dioxide (CO2), a principal constituent of EGR, on combustion and emissions were analysed and quantified experimentally. The use of CO2 to displace oxygen (O2) in the inlet air resulted in: reduction in the O2 supplied to the engine (dilution effect), increased inlet charge thermal capacity (thermal effect), and, potentially, participation of the CO2 in the combustion process (chemical effect). In a separate series of tests the temperature of the engine inlet charge was raised gradually in order to simulate the effect of mixing hot EGR with engine inlet air. Finally, tests were carried out during which the CO2 added to the engine air flow increased the charge mass flowrate to the engine, rather than displacing some of the O2 in the inlet air. It was found that when CO2 displaced O2 in the inlet charge, both the chemical and thermal effects on exhaust emissions were small. However, the dilution effect was substantial, and resulted in very large reductions in exhaust oxides of nitrogen (NO x) at the expense of higher particulate and unburned hydrocarbon (uHC) emissions. Higher inlet charge temperature increased exhaust NO x and particulate emissions, but reduced uHC emissions. Finally, when CO2 was additional to the inlet air charge (rather than displacing O2), large reductions in NOx were recorded with little increase in particulate emissions.

Model Based Boost Pressure and Exhaust Gas Recirculation Rate Control for a Diesel Engine With Variable Turbine Geometry

2001 ◽  
Vol 34 (1) ◽  
pp. 277-282 ◽  
Author(s):  
Joachim Rückert ◽  
Axel Schloßer ◽  
Heinrich Rake ◽  
Bert Kinoo ◽  
Michael Krüger ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Rate Control ◽  
Exhaust Gas Recirculation ◽  
Boost Pressure ◽  
Exhaust Gas ◽  
Variable Turbine Geometry ◽  
Model Based ◽  
Recirculation Rate ◽  
Gas Recirculation

A Numerical Study to Control the Combustion Performance of a Syngas-Fueled HCCI Engine at Medium and High Loads Using Different Piston Bowl Geometry and Exhaust Gas Recirculation

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Kabbir Ali ◽  
Changup Kim ◽  
Yonggyu Lee ◽  
Seungmook Oh ◽  
Kiseong Kim
Keyword(s):  
Numerical Study ◽  
Combustion Process ◽  
Pressure Rise ◽  
Fuel Mixture ◽  
Exhaust Gas Recirculation ◽  
Maximum Pressure ◽  
Exhaust Gas ◽  
Hcci Engine ◽  
Piston Bowl ◽  
Gas Recirculation

Abstract This study aims to analyze the effect of piston bowl geometry on the combustion and emission performance of the syngas-fueled homogenous charge compression ignition (HCCI) engine, which operates under lean air–fuel mixture conditions for power plant usage. Three different piston bowl geometries were used with a reduction of piston bowl depth and squish area ratio of the baseline piston bowl with the same compression ratio of 17.1. Additionally, exhaust gas recirculation (EGR) is used to control the maximum pressure rise rate (MPRR) of syngas-fueled HCCI engines. To simulate the combustion process at medium load (5 bar indicated mean effective pressure (IMEP)) and high loads of (8 and 10 bar IMEP), ansys forte cfd package was used, and the calculated results were compared with Aceves et al.’s Multi-zone HCCI model, using the same chemical kinetics set (Gri-Mech 3.0). All calculations were accomplished at maximum brake torque (MBT) conditions, by sweeping the air–fuel mixture temperature at the inlet valve close (TIVC). This study reveals that the TIVC of the air–fuel mixture and the heat loss rate through the wall are the main factors that influence combustion phasing by changing the piston bowl geometry. It also finds that although pistons B and C give high thermal efficiency, they cannot be used for the combustion process, due to the very high MPRR and NOx emissions. Even though the baseline piston shows high MPRR (23 bar/degree), it is reduced, and reveals an acceptable range of 10–12 bar/degree, using 30% EGR.

Experimental Investigations on Diesel Engine Forced Induction and Exhaust Gas Recirculation (EGR) Using Exhaust Gas Assisted Jet Compressor

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
A. Kalaisselvane ◽  
G. S. Gunasegarane ◽  
N. Alagumurthy ◽  
K. Palaniradja
Keyword(s):  
Diesel Engine ◽  
Power Output ◽  
Exhaust Gas Recirculation ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Specific Power ◽  
Boost Pressure ◽  
Exhaust Gas ◽  
Specific Power Output ◽  
Gas Recirculation

Even though the conventional method of supercharging and turbocharging of an internal combustion engine increases the engine specific power output, part of the shaft power developed by the engine is consumed by the superchargers. The control system that is present in both the chargers further complicates the system. This study proposes a novel method of forced induction in a diesel engine by using a jet compressor run by exhaust gas recirculation (EGR). This method apart from increasing the specific power output reduces the NOx formation by the engine due to forced induction. Performance analysis of the jet compressor using exhaust gas as the motive stream and atmospheric air as the propelled stream was carried out. Using the standard available code, the governing equations were solved numerically to get the optimum operating conditions such as exhaust gas pressure, temperature, and flow rate for a three cylinder diesel engine. The dimensions of the jet compressor were determined by solving the energy balance equations obtained from the constant rate momentum change method. Using the commercial software fluent, the performance optimization of jet compressor used for forced induction in a diesel engine was made for different percentage of EGR input and estimated the power output. From the results obtained, a performance map was drawn for the three cylinder diesel engine to get the optimum boost pressure and maximum entrainment ratio for a given percentage of exhaust gas recirculation and power output. Experiments were conducted on a three cylinder diesel engine fitted with a fabricated jet compressor with EGR used for forced induction application. Results obtained from the experiments were in good agreement with the numerical results obtained from fluent analysis.

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