Twin Fluid Nozzle on UreaSCR Applied to Marine Diesel Engines Hyung Sun Park Sang Ji Lee and Jung Goo Hong School of Mechanical Engineering Kyungpook National University ICFMCE ID: 805914
Download The PPT/PDF document "The Spray Characteristics of" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
The Spray Characteristics of
Twin Fluid Nozzle on Urea-SCR Applied to Marine Diesel Engines
Hyung Sun Park, Sang Ji Lee and Jung Goo Hong
School of Mechanical Engineering, Kyungpook National University
ICFMCE
2017,
November 24-26,
2017,
Dubai
Slide2Opportunity
for the Environment1
By Natural Resources Defense Council (NRDC)
Slide3Opportunity for the Regulation
2
, 2000, 2011, 2016(
≥ 80 %)MARPOL (Marine pollution treaty) Annex VI NOx Emission Limits- International Maritime Organization (IMO) has decided to enforce NOx reduction regulations
Slide4Opportunity for De-NOx tech.
3
3
HAM (Humid Air Motors)EGR (Exhaust Gas Recirculation)
FEW (Fuel & Water Emulsion)
or
DWI (Direct Water Injection)
IEM
(Internal Engine Modification)
LNG
(Liquefied Natural Gas)
SCR (Selective Catalytic Reduction)
De-NOX
Shipping NOx reduction potential by
Azzara
, A. et al.
Slide5Outline for Urea-SCR system
4
Marine diesel engine
Temp. sensor
NOx sensor
Soot blowing
system
Soot blowing
nozzles
Nozzles
Temp. sensor
NOx sensor
Engine control unit
Pulsation
damper
Valves
Pressure
sensor
SCR control unit
Urea pipe
Digital dosing pump
Urea tank
Catalyst
Injector
Dosing
BLUENOX SCR System.
Slide65
Marine diesel engine
Temp. sensor
NOx sensor
Soot blowing
system
Soot blowing
nozzles
Nozzles
Temp. sensor
NOx sensor
Engine control unit
Pulsation
damper
Valves
Pressure
sensor
SCR control unit
Urea pipe
Digital dosing pump
Urea tank
Catalyst
Injector
Outline for Urea-SCR system
Slide7Problem of the present SCR
tech.6
An example of deposit formation on the face of an SCR catalyst monolith. (By John M.E. Storey
et al.)
Stoichiometric imbalance
of the urea consumption
Degradation
of the structural and thermal properties of the
catalyst surface
Since the
exhaust gas temperature and the residence time
in the exhaust pipe
is
insufficient for complete thermal urea
decomposition
,
a major fraction of the injected urea and byproducts by side reaction remain intact before it enters the SCR catalyst.
Catalyst
Exhaust pipe
Slide8Basic Mechanism of Urea-SCR
Evaporation
and thermal decomposition by
exhaust gas temperature
(NH
2
)
2
CO
+ xH
2
O
Urea Solution evaporation
(NH
2
)
2
CO
→
NH
3
+ HNCO
HNCO + H
2
O →
NH
3
+ CO
2
-----------------------------
4NO +
4NH
3
+ O
2
→ 4N
2
+6H
2
O
6NO
2
+
8NH
3
→ 7N
2
+ 12H
2
O
SCR Catalyst
Urea thermal decomposition
NO
x
CO
O
2
HC
N
2
CO
2
H
2
O
Urea Solution Injector
SCR reaction
HNCO hydrolysis
7
Slide98
Sovani et al. (Progress in energy and combustion science
, 2001)- Two-phase flow through a nozzle chokes at a significantly lower velocity than that at which a single phase
flow would choke- Atomization quality is greatly enhanced by the sudden pressure drop at the nozzle exitTypical effervescent atomizer
Perforated
Aerorator
Liquid Inlet
Exit Orifice Hole
Caldyn’s
nozzle
Caldyn’s
Nozzle
Slide10Previous Work : Flow
rate
9Jewe Schroder et al. 2011Caldyn’s
nozzle
- Generally, effervescent nozzle is operated with
0.1 ~ 0.3 of ALR
Relative high ALR
Slide11Effervescent Nozzles
10
Liquid & Air Mixture
AirAirLiquid & Air Mixture
(A)
Outside-in
air injection (B)
Inside-out
air injection
Air
Liquid
Liquid
Liquid
Slide12Configuration of Test Nozzle
11
Exit orifice
Aerorator
D2
D1
Slide13Experimental Setup
12
WaterAir Signal Compressor
On-off valve
On-off valve
Regulator
Stroboscope
CCD camera
Image grabber &
DAQ board
Detector
Laser for SMD
Flow meter
Flow meter
N
2
Pressure transducer
Needle valve
Needle valve
Regulator
*
The
drop size at
200mm
from nozzle tip
Slide14[
실험조건 (540 cases)] - Exit orifice
Dia. (3) - Aerorator Dia. (6) - Injection Pressure (3) - Liquid flow rate (10)Configuration of Test Nozzle
13
Exit orifice Dia.
(mm)
Aerorator
Dia.
(mm)
Exit orifice
Area
(mm
2
)
Aerorator
Area
(mm
2
)
*Area ratio
2.6
1.2
5.31
13.57
2.56
1.5
5.31
21.21
3.99
1.7
5.31
27.24
5.13
2.1
5.31
41.56
7.83
2.5
5.31
58.90
11.09
2.9
5.31
79.26
14.93
3.2
1.2
8.04
13.57
1.69
1.5
8.04
21.21
2.64
1.7
8.04
27.24
3.39
2.1
8.04
41.56
5.17
2.5
8.04
58.90
7.32
2.9
8.04
79.26
9.86
3.7
1.2
10.75
13.57
1.26
1.5
10.75
21.21
1.97
1.7
10.75
27.24
2.53
2.1
10.75
41.56
3.87
2.5
10.75
58.90
5.48
2.9
10.75
79.26
7.37
Nozzle Configuration
Spray Condition
*Area ratio
=
Injection
pressure
(bar
)
2, 2.5 and 3
Liquid mass
flowrate
(kg/min)
0.1 ~ 1.0
Density (kg/m
3
)
Water
1000
Air
1.226
Slide15Comparison of Mass Flow rate
14
- At the same liquid mass flow rate, air mass flow rate increases with
increasing of exit orifice diameter.Exit orifice Dia. (mm)Aerorator Dia. (mm)
2.6
1.2
3.2
1.5
3.7
1.7
*Area ratio
2.56
Injection
Pressure
(bar
)
3
*Area ratio
=
Slide16Comparison of
Mass Flow rate
15
Exit orifice Dia. (mm)Injection
Pressure
(bar)
2.6
3
Slide17Comparison of
Mass Flow rate
16
Exit orifice Dia. (mm)Injection
Pressure
(bar)
3.2
3
Slide18Comparison of
Mass Flow rate
17
Exit orifice Dia. (mm)Injection
Pressure
(bar)
3.7
3
Slide19Droplet Size Measurement
18
- Compared with
Caldyn’s data, it has same tendency.- SMD is not a large difference in the value of ALR ratio in 0.3 or more.
Slide20Droplet Size Measurement
19
Exit orifice Dia.
(mm)
Aerorator
Dia.
(mm)
*Area ratio
2.6
1.2
2.56
1.7
5.13
2.5
11.09
Injection
Pressure
(bar
)
3
SMD is not affected by area ratio of an
efferverscent
nozzle.
Slide21Droplet Size Measurement
20
SMD is not affected by area ratio of an efferverscent nozzle.Exit orifice Dia.
(mm)
Aerorator
Dia.
(mm)
*Area ratio
3.7
1.2
1.26
1.7
2.53
2.5
5.48
Injection
Pressure
(bar
)
3
Slide22Summary
21
[Conclusion]
The liquid flow rate of the effervescent nozzle used in this study is affected by the diameter of the exit orifice.
It was found that the change of the liquid and air flow rate according to the
aerorator
diameter
was
not large at the same exit orifice diameter
.
In the case of
ALR above 0.3
, there is
almost no change in SMD
even if the air flow rate increases
.
In the
efferverscent
nozzle
,
the droplet size
is
not affected
by the area ratio
.
[Application]
From
the results of this study, the
droplet size
can be predicted according to various
ALR and area
ratios
.
It can be applied to Urea-SCR nozzle design technology according to various engine power
.
Slide23