2004-01-0154

Optimization of Urea SCR deNOx Systems forHD Diesel Engines

Rinie van Helden, Ruud Verbeek and Frank Willems

Reinier van der Welle

ABSTRACT

•••

INTRODUCTION

•

••

CATALYST CONFIGURATION AND UREADOSAGE CONTROL

•

•

NO

x (%

)

NO

x C

on

vers

ion

[%

]

tem

per

atu

re f

req

uen

cy

Catalyst temperature [°C]

UREA HYDROLYSIS AND MIXING

••

camera

glasstubeglass

window

Inletchamber

Inlet pipe

SCR catalyst

SCR SYSTEM MODELLING

••

•

•

DISCUSSION

•

•

Design of system layout Control of urea dosage

CONCLUSIONS

•

•

•

•

•

•

•

REFERENCES

ACKNOWLEDGMENTS

APPENDIX

- Solid phase

NOdaNH rrrt

−−=∂

∂3

θ

- Gas phase

)(33

daNHNH

rrx

Cv

t

C−Ω−

∂∂

−=∂

∂

NONONO rx

Cv

t

CΩ−

∂∂

−=∂

∂

Ωv

)1(33

0NHNHaa Ckr θ−=

3

30 )1(

0NH

RT

E

dds

NHd

ekr θαθ−−

=

*θ

−=−−

*3

3

31*0 NH

NH

s

NO

eCekr NHNORT

E

NONO

θ

θ

θ

)(,, sgsgsgg

gpggg

gpgg TTahx

Tcv

t

Tc −−

∂∂

−=∂

∂↔↔ρερε

rNOasasas

sgsgsgs

sgs

spsg

HrTTah

TTahx

T

t

Tc

∆Ω+−−

−+∂∂

−=∂

∂−

↔↔

↔↔

)(

)()1()1(2

2

, λερε

2

Re

32v

dx

pg

h

ρ⋅

=∂∂

α

Ω

µ

3NHθ

*3NHθ

ρ

ε

∆ Hr

λ

a

C

cp

dh

E

0ak

0dk

0NOk

p

R

Re

T

v

x