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Experimental and 3D, embedded modeling for diesel engine SCR deposit

  • F. QianEmail author
  • L. Lü
  • T. Feng
  • D. Yang
Article
  • 222 Downloads

Abstract

Nowadays, the selective catalytic reduction (SCR) is a promising solution to fulfill stringent nitrogen oxide (NOX) emission standards enforced by worldwide regulation bodies for lean burning engines. However, in the practical operation, urea deposits occur under unfavorable conditions, which bring about a failure of urea dosing strategy, affect the SCR system de-NOx performance and lowering the fuel economy by increasing the engine back pressure. This paper will present 3D deposit model, which can be used to predict the deposit position. Furthermore, a model-based controls strategy and calibration are designed. The comparison test results of both engine emission tests and vehicle field tests shows there is significant deposits improvement with the embedded model.

Key Words

Diesel engine Urea-SCR Deposit 3D model Embedded model 

Nomenclature

SCR

selected catalyst reduction

NOx

nitrogen oxide

Adblue

32.5 % urea solution

SV

space velocity

CYA

cyanuric acid

NSR

NH3/NOX ratio

DCU

dosing control unit

ETC

european transient cycle

Fidr

drag force

Fip

pressure force

A

frequency factor

Dd

droplet diameter

Ea

activation energy

R

universal gas constant

Red

reynolds number

cHCNO

concentration of HCNO

Areafilmpatch

film patch area

St

stanton number

mDeposit

mass of deposits

mf,lowTemp

mass of wallfilm with low temperature

wurea

urea mass fraction in the wallfilm

wmiler

limitation of Miller curve.

mInj

mass of the injected Adblue

xstored

percentage of injected Adblue to wallfilm

mevap

the mass of evaporated water

mde

urea mass which involved in themolysis reaction

Pf

wallfilm density

Vf

the wallfilm volume

Af

the wallfilm area

K

heat transfer coefficient.

cp,f

wallfilm specific heat

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Copyright information

© The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  1. 1.Key Laboratory of High Performance Ship of Ministry of EducationWuhan University of TechnologyHubeiChina

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