Impact of Combination of EGR, SCR and DPF Technologies for the Low-Emission Rail Diesel Engines
Journal article, 2015

The EU emission standards for new rail diesel engines are becoming more stringent: stage IV emission targets have just come into effect, while stage V is in under considerations. Both exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) technologies can be used to reduce nitric oxide (NOx) emissions, while the PM emission control requires a diesel particulate filter (DPF). The use of SCR requires on-board storage of urea, while the use of DPF needs to take into account its impact on engine efficiency performance. Both of these technologies require specific studies when applied to the rail engines; in particular, it becomes necessary to evaluate the engine performance trade-offs in order to evaluate how these technologies can be utilized efficiently in rail applications in order to meet current and future emission standards. The present study assesses the application of these technologies in diesel railcars on a quantitative basis using oneand three-dimensional numerical simulation tools. In particular, the study considers a 560-kWrailcar engine with the use of different technology combinations for NOx reduction: SCR or EGR + DPF, and EGR + DPF + SCR. The NOx and PM emission performances are evaluated over the C1 homologation cycle and, in the case of the DPF, over an approximated railcar driving cycle as well. Several BSNOx targets were considered: 2 g/kWh, 1 g/kWh, and 0.4 g/kWh. Simulation results indicate that EGR + DPF + SCR-based solution is necessary to achieve stage IV emission limits for the 560-kW engine. On the other hand, SCR-based solutions have the potential to go beyond the stage IV NOx limit through scaling up the size of the SCR device and the on-board urea storage.

selective catalytic reduction

particulate emissions

nox emissions

exhaust gas recirculation

diesel particulate filter


Athanasios Konstadopoulos

Aristotle University of Thessaloniki

Centre for Research and Technology Hellas (CERTH)

Margaritis Kostoglou

Centre for Research and Technology Hellas (CERTH)

Aristotle University of Thessaloniki

Carlo Beatrice

Istituto Motori

Gabriele Di Blasio

Istituto Motori

Abdurrahman Imren

Chalmers, Applied Mechanics

Ingemar Denbratt

Chalmers, Applied Mechanics, Combustion and Propulsion Systems

Emission Control Science and Technology

2199-3637 (eISSN)

Vol. 1 3 213-225

Subject Categories

Mechanical Engineering

Driving Forces

Sustainable development

Areas of Advance




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