A Comprehensive Physics-Based Model for Medium-Duty Diesel Engine With Exhaust Gas Recirculation

2007 ◽  
Author(s):  
Alok A. Joshi ◽  
Scott James ◽  
Peter Meckl ◽  
Galen King ◽  
Kristofer Jennings
Keyword(s):  
Heat Transfer ◽  
Exhaust Gas Recirculation ◽  
Boost Pressure ◽  
Exhaust Gas ◽  
Variable Geometry ◽  
Transfer Effects ◽  
Variable Geometry Turbine ◽  
Heat Transfer Effects ◽  
Egr Cooler ◽  
Gas Recirculation

Physics-based models of diesel engines with exhaust gas recirculation and a variable geometry turbine (EGR/VGT) have been developed extensively in the control system design community. However, these models omit the heat transfer effects of the charge-air cooler and the recirculated exhaust gas cooler in order to avoid the added complexity in model order for online implementation. Generally, there is no need to include these effects if the purpose of the model is to control the target variables, such as boost pressure and air-to-fuel ratio. In this paper, after surveying the existing state of physics-based models for the EGR/VGT subsystem, a comprehensive model of the EGR/VGT subsystem is developed. This model includes heat transfer effects in the coolers, pressure drops across air filters and pipes, and mass flow rate calculations for a variable geometry turbine and an exhaust gas recirculation control valve. The purpose and scope of this work is offline modeling-for-diagnostics. Such models, though complex, will assist in the fault sensitivity analysis of a subsystem while avoiding any destructive testing when a major design modification in the EGR/VGT subsystem is proposed. For example, the impact of charge-water or EGR cooler degradation on the boost pressure and the air-to-fuel ratio can be studied with such models to further help in designing diagnostic reasoning strategies. Simulation performed using the proposed physicsbased model demonstrates a dominant failure effect of an EGR cooler coolant leak over a charge-water cooler water leak on the properties of the intake air.

The study of heat transfer for nanofluid with carbon nano particle in an exhaust gas recirculation (EGR) cooler

2013 ◽  
Vol 49 (7) ◽  
pp. 1051-1055 ◽  
Author(s):  
Seongsoo Kim ◽  
Hanshik Chung ◽  
Hyomin Jeong ◽  
Byungho Lee ◽  
Bayanjargal Ochirkhuyag ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Nano Particle ◽  
Egr Cooler ◽  
Gas Recirculation

Turbocharging strategy among variable geometry turbine, two-stage turbine, and asymmetric two-scroll turbine for energy and emission in diesel engines

2019 ◽  
Vol 234 (7) ◽  
pp. 900-914
Author(s):  
Dengting Zhu ◽  
Zhenzhong Sun ◽  
Xinqian Zheng
Keyword(s):  
Internal Combustion Engines ◽  
Numerical Models ◽  
Exhaust Gas Recirculation ◽  
Internal Combustion ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Variable Geometry ◽  
Two Stage ◽  
Variable Geometry Turbine ◽  
Gas Recirculation

Energy saving and emission reduction are very urgent for internal combustion engines. Turbocharging and exhaust gas recirculation technologies are very significant for emissions and fuel economy of internal combustion engines. Various after-treatment technologies in internal combustion engines have different requirements for exhaust gas recirculation rates. However, it is not clear how to choose turbocharging technologies for different exhaust gas recirculation requirements. This work has indicated the direction to the turbocharging strategy among the variable geometry, two-stage, and asymmetric twin-scroll turbocharging for different exhaust gas recirculation rates. In the paper, a test bench engine experiment was presented to validate the numerical models of the three diesel engines employed with the asymmetric twin-scroll turbine, two-stage turbine, and variable geometry turbine. On the basis of the numerical models, the turbocharging routes among the three turbocharging approaches under different requirements for EGR rates are studied, and the other significant performances of the three turbines were also discussed. The results show that there is an inflection point in the relative advantages of asymmetric, variable geometry, and two-stage turbocharged engines. At the full engine load, when the EGR rate is lower than 29%, the two-stage turbocharging technology has the best performances. However, when the exhaust gas recirculation rate is higher than 29%, the asymmetric twin-scroll turbocharging is the best choice and more appropriate for driving high exhaust gas recirculation rates. The work may offer guidelines to choose the most suitable turbocharging technology for engine engineers and manufacturers to achieve further improvements in engine energy and emissions.

Analysis of the Exhaust Gas Recirculation System Performance in Modern Diesel Engines

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Stefano d'Ambrosio ◽  
Alessandro Ferrari ◽  
Ezio Spessa
Keyword(s):  
Control Valve ◽  
Experimental Tests ◽  
Detailed Comparison ◽  
Exhaust Gas Recirculation ◽  
Valve Lift ◽  
Exhaust Gas ◽  
Flow Area ◽  
Tube Type ◽  
Egr Cooler ◽  
Gas Recirculation

Exhaust gas recirculation (EGR) is extensively employed in diesel combustion engines to achieve nitrogen oxides emission targets. The EGR is often cooled in order to increase the effectiveness of the strategy, even though this leads to a further undesired impact on particulate matter and hydrocarbons. Experimental tests were carried out on a diesel engine at a dynamometer rig under steady-state speed and load working conditions that were considered relevant for the New European Driving Cycle. Two different shell and tube-type EGR coolers were compared, in terms of the pressure and temperature of the exhaust and intake lines, to evaluate thermal effectiveness and induced pumping losses. All the relevant engine parameters were acquired along EGR trade-off curves, in order to perform a detailed comparison of the two coolers. The effect of intake throttling operation on increasing the EGR ratio was also investigated. A purposely designed aging procedure was run in order to characterize the deterioration of the thermal effectiveness and verify whether clogging of the EGR cooler occurred. The EGR mass flow-rate dependence on the pressure and temperature upstream of the turbine as well as the pressure downstream of the EGR control valve was modeled by means of the expression for convergent nozzles. The restricted flow-area at the valve-seat passage and the discharge coefficient were accurately determined as functions of the valve lift.

Optimal Control of Variable Geometry Turbocharged Diesel Engines With Exhaust Gas Recirculation

1999 ◽  
Author(s):  
I. Kolmanovsky ◽  
M. van Nieuwstadt ◽  
P. Moraal
Keyword(s):  
Optimal Control ◽  
Diesel Engines ◽  
Controller Design ◽  
Exhaust Gas Recirculation ◽  
Feedback Controller ◽  
Exhaust Gas ◽  
Variable Geometry ◽  
Variable Geometry Turbocharger ◽  
Transient Control ◽  
Gas Recirculation

Abstract This paper presents results on the optimal transient control of diesel engines with exhaust gas recirculation (EGR) and a variable geometry turbocharger (VGT). The implications of these results for feedback controller design axe discussed.

A Simplified Model for Deposition and Removal of Soot Particles in an Exhaust Gas Recirculation Cooler

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
A. Reza Razmavar ◽  
M. Reza Malayeri
Keyword(s):  
Maximum Velocity ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Rolling Moment ◽  
Soot Particles ◽  
Exhaust Gases ◽  
Particulate Fouling ◽  
Efficient Performance ◽  
Egr Cooler ◽  
Gas Recirculation

Nitrogen oxides (NOx) emissions from diesel engines can profoundly be suppressed if a portion of exhaust gases is cooled through a heat exchanger known as exhaust gas recirculation (EGR) cooler and returned to the intake of the combustion chamber. One major hurdle though for the efficient performance of EGR coolers is the deposition of various species, i.e., particulate matter (PM) on the surface of EGR coolers. In this study, a model is proposed for the deposition and removal of soot particles carried by the exhaust gases in a tubular cooler. The model takes thermophoresis into account as the primary deposition mechanism. Several removal mechanisms of incident particle impact, shear force, and rolling moment (RM) have rigorously been examined to obtain the critical velocity that is the maximum velocity at which the particulate fouling can profoundly be suppressed. The results show that the dominant removal mechanism changes from one to another based particle size and gas velocity. Based on particle mass and energy conservation equations, a model for the fouling resistance has also been developed which shows satisfactory agreement when compared with the fouling experimental results.

Diesel air path control using pressure difference: Pumping loss and aging considerations

2018 ◽  
Vol 233 (10) ◽  
pp. 2421-2431
Author(s):  
Rasoul Salehi ◽  
Anna Stefanopoulou ◽  
Bruce Vernham
Keyword(s):  
Internal Control ◽  
Pressure Difference ◽  
Exhaust Gas Recirculation ◽  
Particulate Filter ◽  
Output Coupling ◽  
Boost Pressure ◽  
Exhaust Gas ◽  
Linear Quadratic ◽  
Output Controller ◽  
Gas Recirculation

Pressure difference across the exhaust and intake manifolds ([Formula: see text] P) is a crucial variable to control the pumping loss and cylinder charge dilution through the exhaust gas recirculation in a diesel engine. This paper presents a novel architecture for controlling [Formula: see text] P and the engine-out NO x emissions, which increases the controller tolerance to engine components aging. The architecture has an internal control loop, designed as a two-input two-output controller, to coordinate the exhaust gas recirculation and variable geometry turbine valves. Using feedback from [Formula: see text] P and the estimated cylinder oxygen ratio [Formula: see text] cyl, the two-input two-output controller regulates the pumping loss and the engine NO x emissions. To reduce high turbo lag and its associated slow air–fuel ratio ([Formula: see text]) response, which are inherent features of a [Formula: see text] P-based control strategy, the two-input two-output linear quadratic controller is tuned such that [Formula: see text] is also regulated, but only during fast transients. An external loop is supplementing the core two-input two-output controller correcting the internal loop set points to reduce the effects of [Formula: see text] cyl estimation errors on NO x control and ensure [Formula: see text] stays above a minimum value, [Formula: see text] min, critical for smoke emissions. As a feature of the proposed control system, direct feedback from [Formula: see text] P increases pumping loss robustness to common degradation in diesel engines, namely, turbine efficiency and diesel particulate filter blockage due to ash deposit, compared to a conventional boost pressure–based controller. Also, it is shown that the input–output coupling structure of the proposed two-input two-output controller and use of the NO x feedback mitigate effects of exhaust gas recirculation fouling and associated exhaust gas recirculation valve saturation on increase in NO x emission.

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