scholarly journals Modelling the Exhaust Gas Recirculation Mass Flow Rate in Modern Diesel Engines

2016 ◽  
Author(s):  
Zhijia Yang ◽  
Edward Winward ◽  
Gary O'Brien ◽  
Richard Stobart ◽  
Dezong Zhao
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Diesel Engines ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Gas Recirculation

The Heat Transfer Characteristics of Exhaust Gas Recirculation (EGR) Cooling Devices

2002 ◽  
Author(s):  
B. I. Ismail ◽  
R. Zhang ◽  
D. Ewing ◽  
J. S. Cotton ◽  
J.-S. Chang
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Exhaust Gas Recirculation ◽  
Inlet Temperature ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Cooling Device ◽  
Gas Recirculation

A one-dimensional steady state model was developed to predict the heat transfer performance of a shell (liquid)-and-tube (gas) heat exchanger used as a cooling device for exhaust gas recirculation (EGR) application where there is a significant temperature drop across the device. The predictions of the model results were compared with experimental measurements and the trends were found to be in good agreement for most of the transitional and turbulent regimes. The results showed that the exit gas temperature increases with increasing gas mass flow rate at fixed gas inlet temperature and coolant flow rate. It was also found that the exit gas temperature was essentially independent of the coolant flow rate for the typical operating range but did depend on the coolant inlet temperature. It was observed that the pressure drop across the cooling device was not a strong function of the gas inlet temperature. The heat-transfer effectiveness of the cooling device was found to slightly depend on the gas mass flow rate and inlet gas temperature. A preliminary analysis showed that fouling in the EGR cooling device can have a significant effect on both the thermal and hydraulic performance of the cooling device.

scholarly journals Verification and Comparison of Nine Exhaust Gas Recirculation Mass Flow Rate Estimation Methods

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7291
Author(s):  
Ádám Nyerges ◽  
Máté Zöldy
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Estimation Methods ◽  
Exhaust Gas ◽  
Flow Rates ◽  
Air Mass ◽  
Rate Estimation ◽  
Mass Flow Rates ◽  
Gas Recirculation

Modern Diesel engines have complex exhaust gas recirculation (EGR) systems. Due to the high temperatures, it is a typical issue to measure EGR mass flow rates in these complex control systems. Therefore, it is expedient to estimate it. Several sensed values can help the estimation: the fresh air mass flow rate, the fuel consumption, pressures, temperatures and mass fractions in the air path system. In most of the articles, the EGR mass flow rate estimation is done by the pressures. However, gas composition based models usually would be better for control aims. In this paper, nine EGR estimation methods will be presented: an important outcome is to present the required sensor architectures and estimation challenges. The comparison will be made by measurement results both in stationary operation points and transient cycles. The estimated EGR mass flow rates will be evaluated by verification conditions. The results will prove that the intake and exhaust side oxygen sensors can give verifiable signals for EGR mass flow rate estimation. In contrast, the applied fresh air mass flow rate and the nitrogen-oxide signals are not accurate enough to provide verifiable EGR mass flow rates in every operating condition. The effects of sensor inaccuracies will also be considered.

A new mass and temperature control valve for exhaust gas recirculation in car diesel engines

MTZ worldwide ◽  
2007 ◽  
Vol 68 (12) ◽  
pp. 21-23
Author(s):  
Thomas Holzbaur ◽  
Eike Willers ◽  
Achim Hess ◽  
Hans-Peter Klein ◽  
Markus Schuessler ◽  
...  
Keyword(s):  
Temperature Control ◽  
Diesel Engines ◽  
Control Valve ◽  
Exhaust Gas Recirculation ◽  
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.

Effect of hydraulic flow rate, injection timing, and exhaust gas recirculation on particulate and gaseous emissions in a light-duty diesel engine

2019 ◽  
Vol 234 (5) ◽  
pp. 1279-1293 ◽  
Author(s):  
Khawar Mohiuddin ◽  
Minhoo Choi ◽  
Junkyu Park ◽  
Sungwook Park
Keyword(s):  
Diesel Engine ◽  
Flow Rate ◽  
Particle Number ◽  
Exhaust Gas Recirculation ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Gaseous Emissions ◽  
Spray Tip Penetration ◽  
Hydraulic Flow ◽  
Gas Recirculation

Nozzle hydraulic flow rate is a critical parameter that affects the combustion process and plays a vital role in the production of emissions from a diesel engine. In this study, injection characteristics, such as normalized injection rate and spray tip penetration, were analyzed for different hydraulic flow rate injectors with the help of spray experiments. To further investigate the effects of hydraulic flow rate on engine-out particulate and gaseous emissions, engine experiments were performed for different values of hydraulic flow rate in multiple injectors. Various operating conditions and loading configurations were examined, and the effects of varying start of injection and exhaust gas recirculation rates for different hydraulic flow rates were analyzed. A separate Pegasor Particle Sensor (PPS-M) sensor was used to measure and collect data on the particle number, and an analysis was conducted to investigate the relation of particle number with hydraulic flow rate, injection timing, and exhaust gas recirculation rate. Results of the spray experiment exhibited a decreasing injection duration and increasing spray tip penetration with increasing hydraulic flow rate. Effect of hydraulic flow rate on combustion and emission characteristics were analyzed from engine experiment results. Least ignition delay was achieved using a smaller hole diameter, retarded injection timing, and lowest EGR%. Higher hydraulic flow rate with retarded injection timing and higher EGR% helped in reduction of NOx emissions and brake-specific fuel consumption, but particulate emissions were increased. Best particulate matter–NOx trade-off was achieved with lowest hydraulic flow rate.

Diesel engines with low-pressure exhaust-gas recirculation

MTZ worldwide ◽  
2008 ◽  
Vol 69 (2) ◽  
pp. 20-26 ◽  
Author(s):  
Stefan Münz ◽  
Christiane Römuss ◽  
Peter Schmidt ◽  
Kai-Henning Brune ◽  
Heinz-Peter Schiffer
Keyword(s):  
Diesel Engines ◽  
Exhaust Gas Recirculation ◽  
Low Pressure ◽  
Exhaust Gas ◽  
Gas Recirculation

scholarly journals Validated Analytical Modeling of Diesel Engines Intake Manifold with a Flexible Crankshaft

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1287
Author(s):  
Salah A.M. Elmoselhy ◽  
Waleed F. Faris ◽  
Hesham A. Rakha
Keyword(s):  
Mass Flow Rate ◽  
Relative Error ◽  
Mass Flow ◽  
Flow Rate ◽  
Diesel Engines ◽  
Analytical Modeling ◽  
Vacuum Pressure ◽  
Analytical Models ◽  
Intake Manifold ◽  
Flow Losses

The flexibility of a crankshaft exhibits significant nonlinearities in the analysis of diesel engines performance, particularly at rotational speeds of around 2000 rpm. Given the explainable mathematical trends of the analytical model and the lack of available analytical modeling of the diesel engines intake manifold with a flexible crankshaft, the present study develops and validates such a model. In the present paper, the mass flow rate of air that goes from intake manifold into all the cylinders of the engine with a flexible crankshaft has been analytically modeled. The analytical models of the mass flow rate of air and gas speed dynamics have been validated using case studies and the ORNL and EPA Freeway standard drive cycles showing a relative error of 7.5% and 11%, respectively. Such values of relative error are on average less than those of widely recognized models in this field, such as the GT-Power and the CMEM, respectively. A simplified version for control applications of the developed models has been developed based on a sensitivity analysis. It has been found that the flexibility of a crankshaft decreases the mass flow rate of air that goes into cylinders, resulting in an unfavorable higher rate of exhaust emissions like CO. It has also been found that the pressure of the gas inside the cylinder during the intake stroke has four elements: a driving element (intake manifold pressure) and draining elements (vacuum pressure and flow losses and inertial effect of rotating mass). The element of the least effect amongst these four elements is the vacuum pressure that results from the piston's inertia and acceleration. The element of the largest effect is the pressure drop that takes place in the cylinder because of the air/gas flow losses. These developed models are explainable and widely valid so that they can help in better analyzing the performance of diesel engines.

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