Transcript
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DIESEL - RK
RK-model of mixture formation and combustion in a dieseltakes intoaccount:
- piston bowl shape;
- swirl intensity;- injection profile, including multistage microprocessor controlled injection;
- number, diameter and directions of sprayer nozzles;
- interaction of sprays with walls;
- interaction of wall surface flows formed by sprays among themselves.
Built-in procedure of multiparameter optimizing.The library of searchingprocedures contains 14 methods of the nonlinear programming.
Model of EGR system.
Software for thermodynamic simulation and
optimizing of ICEAdvanced abilities:
"Fuel Spray Visualization" code.This code makes it possible in a pictorialform to analyze an animation picture of interaction of fuel sprays with combustion
chamber walls, with swirl and among themselves.
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Simulation of the fuel sprays in the swirling air flow
Penetration of spray tip (2) and
boundaries of WSF* (3-6) as the
functions of time
Interaction of spray with a wall Schematic Fuel spray structure
Character zones
1. Rare environment of free spray
2. Dense axial core of free jet
3. Dense forward front
4. Rare environment of WSF
5. Dense core of WSF6. Dense forward front of WSF
7. Axial conical core of WSF
1. Velocity
2. Penetration
3. Right and left outer
boundaries of WSF
4. Forward outer
boundary of WSF5. Back outer
boundary of WSF
6. Free spray
* WSF is the so-called Wall Surface Flow of air
with high density of fuel drops
# Frame
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Simulation of the fuel sprays in the swirling air flow
Piston bowl is a figure of revolutions.
Direction of each fuel jet is
specified in the two planes.
Swirl intensity is specified as a
swirl number.
The trajectories and deformations of free
sprays as well movement and deformation
of wall surface flows formed by sprays are
simulated in view of influence of
tangential air swirl and angle between
spray and wall.
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Simulation of fuel sprays in the swirling air flow
Results of simulation of jets and
WSF development
Sketches of shadowgraphmovieof WSF development
Allocation of fuel in the zones for each spray is presented in graph
Spray # 3Spray # 1
Heat release rate
dx/d
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74,69
0
5
10
15
20
25
Fractionoffuelinthezone,
%
Environment 17,03 19,61 20,95 17,09 74,69
Free Jet Core 0,08 0,38 0,61 0,09 1,17
WSF 7,84 5,01 3,43 7,57 23,85
Cylinder Head 0,05 0 0 0,24 0,29
Spray #1 Spray # 2 Spray # 3 Spray # 4 Sum
Analysis of allocation of fuel in the character zones
Tractor diesel
S/D = 140 / 120
RPM = 1800;BMEP = 7.7 bar
*WSF - wallsurface flow
formed by jets
on piston surface
Click picture to zoom
and start visualization
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Swirl occurred deformation of Wall Surface Flow
Simulation Measurement
ge,
g/kW h
Single cylinder
diesel
S/D = 140 / 130
RPM = 2100;
BMEP = 7.0 bar
*WSF - wall surface flowformed by jets on piston surface
- Swirl number
Search of optimum value of swirl intensity
Fraction of fuel in the
zones of WSF crossing
Fraction of fuel in
the Environment
ge
Verification of the calculated data compared to experimental ones
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Simulation of diesel combustion
over the whole speed range
Comparison between calculated and experimental data
Truck diesel S/D = 120 / 120
SimulationMeasurement Click picture to zoom
http://gifview.exe%20kamaz%202200.gif%20/delay=007http://gifview.exe%20kamaz%201400.gif%20/delay=007http://gifview.exe%20kamaz%201000.gif%20/delay=0078/14/2019 Diesel - Rk 2003 Audio
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Simulation of soot emission in the diesel
over the whole speed range
Comparison between calculated
and experimental data
SimulationMeasurement
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NOx emission simulation
The oxides of nitrogen are formed in a zone of combustion by the
chain mechanism. The main reactions are described by the Zeldovichscheme:
O2 2O;
N2 + O NO + N;
N + O2 NO + O.
Temperature in a zone of combustion is defined by zone model.
The calculation of nitrogen oxides formation is carried out on the
kinetic equation.
On each step the equilibrium composition of 18 components isdefined in a zone of combustion.
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11 components:O, O2 , H, H2 , OH, H2O,
CO2 , N, N2 , NO, NO2
Model of nitrogen oxides formation with
calculation of equilibrium of 18 components
18 components:O, O2 , O3, H, H2 , OH, H2O,
C, CO, CO2 , CH4, N, N2 ,
NO, NO2, NH3, HNO3, HCN
Equilibrium equations:
;;;21
HH3
23
OO2
21
OO1 2232ppKppKppK ===
Material balance equations:
HCNOOC ;; SSSSSS ppp ===
The Dalton equation :
HCNHNONHNONONNCH
COCOHOHHHOOO
33224
22232
pppppppp
pppppppppp
++++++++
+++++++++=
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Model of nitrogen oxides formation with
calculation of equilibrium of 18 componentsComparison of calculated and experimental data
0
200
400
600
800
1000
1200
1 2 3 4 5 6 7 8 9 10 11 12 13
Regime number
NOx measurement
NOx simulation
NOx formation in exhaust gas of truck diesel YaMZ-7512
at operation on 13 regimes cycle.
NOxfraction,
pp
m
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NOx emission calculation
at different values of Compression Ratio
Diesel S/D = 120 / 105
Full load:
Ne = 22 kW, RPM = 2000
NOx,
g/3
ge,
g/kWh
CR = 16.2
CR = 18.8
Simulation Measurement
Click picture to
zoom and start
visualization
CR
Comparison between calculated
and experimental data
ll i f hi h f C i l i
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Illustration of high accuracy of ICE simulation
over the whole operating range
Truck diesel: S/D=140/130
Click picture to zoom and start visualization
http://gifview.exe%201400_3_1.gif%20/delay=020http://gifview.exe%201400_3_1.gif%20/delay=020http://gifview.exe%202100_3_1.gif%20/delay=025http://gifview.exe%202100_2_1.gif%20%20/delay=030http://gifview.exe%20%202100_1.gif%20/delay=040http://gifview.exe%201400_1.gif%20/delay=040http://gifview.exe%201400_2_1.gif%20/delay=0308/14/2019 Diesel - Rk 2003 Audio
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over the whole operating range
Truck diesel: S/D=140/130
Comparison between calculated and experimental data
is the relative error
Measur. Calcul. ,
Ne 24.4 25.1 2.9
SFC 577 560 2.9
NOx 240 260 8.3
Measur. Calcul. ,%
Ne 122.2 122. 0
SFC 258 258 0
NOx 980 930 5.1
Measur. Calcul. ,%
Ne 244.3 252 3.1
SFC 240 232 3.3
NOx 1920 1869 2.6
Measur. Calcul ,%
Ne 180.3 178. 1.2
SFC 219 222 1.4
NOx 2160 1990 7.9
Measur. Calcul ,%
Ne 90.2 86 4.6
SFC 223 235 5.4NOx 1430 1023 28
Measur. Calcul. ,%
Ne 18 16.2 10
SFC 411 456 11
NOx 280 320 14
Ill t ti f hi h f ICE i l ti
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Illustration of high accuracy of ICE simulation
over the whole operating range
Experiment Simulation
Characteristic of locomotive diesel S/D=260/260
Click picture to zoom and start visualization
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Illustration of high accuracy of ICE simulation
over the whole operating range
Experiment Simulation
Ne ge Air Flow Tt Smoke NO
% 2.5 1.9 1.9 3.3 0 0.6
Ne ge Air Flow Tt Smoke NOx% 0.7 0 6.2 0.9 14.2 2
Comparison between calculated and experimental data
is the relative error.
Air Flow is the Air flow rate; ge is the specific fuel consumpti
Tt is Turbine inlet temperature;Ne is engine power;
Characteristic of locomotive diesel S/D=260/260
Ne ge Air Flow Tt Smoke NOx
% 3.6 3.5 1 1.2 7.1 0.7
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Simulation of combustion in diesel with
multistage injection of fuel
Locomotive diesel S/D=260/260,
Full load.
Piston bowl: Shallow Hesselman
Click picture to start visualization
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Two engine parameters are changed in
X, Y directions from MIN up to MAX
with fixed steps.
DIESEL-4t carries out the ICE
simulation in the bundles of the grid.
2D optimization tasks
Use the scanning if the problem of optimization of any process can be formulated as
bivariate (number of arguments is 2)
The results of scanning may be displayed as 3-D diagram
... or as isolines families
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Optimizing mixture formation to decrease
NOx emission in the tractor dieselBase configuration Optimum solution
Diesel S / D = 120 / 105Ne = 22 kW, RPM = 2000
Parameter Base Optimum
Compression Ratio 16 19.5
Fuel-Injection timing, deg BTC 16 11.5
Fuel nozzle design 3 x 0.3; = 56o / 66o 3 x 0.22; = 75o
-----------------------------------------------------------------------------------------------------
Max Pressure of Injection, bar 520 665
Specific fuel consumption, g/kW h 239 236
Smoke level, Hartridge number 17.2 17.9
NOx emission, g/m3 3.4 1.92 = 40%
-----------------------------------------------------------------------------------------------------Uo - Injection ratedx/dFi - Heat release rate.
M l i i i i i f h hi h
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Multiparametric optimization of the high-
speed dieselto decrease its emission levelGoal of optimizing: decrease of particulate matter emission () and
nitrogen oxides emission(NOx).
MIN
CR - Compression ratio;
i, di - Number and Diameter of injector nozzles;
, - Injection duration and Injection Timing, deg B TDC;
InjProf - Injection profile;
PistBowl - Piston bowl shape;
NuzzlDir - Injector nozzles design.
)(XfNOx
NOxC
PM
PMCF
o
NOx
o
PM =+=
Arguments:
=Y
Limits:Pz - Maximum cylinder pressure (Pz < 150 bar);
Pinj - Maximum injection pressure (Pinj < 1500 bar);ge - Specific fuel consumption (ge < 260 g/kW h).
=X
The complex arguments: Injection profile, Piston bowl shape, Injector nozzles design are
assigned by user by experience and analysis of allocation of fuel in the zones (by using FJV
software). For searching the optimum combination of scalar arguments the well known
algorithms of nonlinear programming are used.
M lti t i ti i ti f th hi h
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Multiparametric optimization of the high-
speed dieselto decrease its emission level
Alternate designsof the piston bowl ( PistBowl )
Variants of the injection profiles ( InjProf )
Alternate designsof the injector nozzles ( NuzzlDir )
Base:
#
Alternates:
Base Alternate # 1 (narrowed) Alternate #2
i = 5, angle between jet axes: 146 ; i = 5, angle between jet axes : 134 ;
i = 6, angle between jet axes : 146 ; i = 6, angle between jet axes : 134 .For each combination of complex arguments: the searching rational combination of the varied
factors [F = f(, dc, , ) => MIN ] is entrusted to a formal procedure of non-linearro rammin .
Complex arguments
M lti t i ti i ti f th hi h
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Multiparametric optimization of the high-
speed dieselto decrease its emission level
*N - Number of ICE simulation sessions at optimization
1,31 1,371,454 1,4
1,33 1,32 1,31
2,52
0
0,5
1
1,5
2
2,5
3
F
Results of optimizing obtained by different methods for one of combination of the
complex arguments
o
NOx
o
PMNOx
NOxC
PM
PMCF +=
NuzzlDir:5 di 146
PistBowl: Base
N=46 N=114 N=67 N=58 N=102 N=118 N=115
Method:
Rosenbrok
Method:
Pearson
Gradient
method
Method:
Flatcher-
Reeves
Method:
Newton-
Rafson
Method:
Broiden
Method:
Davidone-
Flatcher-
Powell
Base
configuration
InjProf: 1
Combination of the complex arguments
Optimum
solutionScalar
arguments:CR = 20;
di = 0.195; = 24.4;
= 9.4.
Limits:Pz =139 bar;
Pinj = 1441 bar;
ge = 251 g/kWh
NOx=6.11
PM=0.495
NOx=7.43
PM=0.074
NOx=7.25
PM=0.101
NOx=8.66PM=0.067
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Multiparametric optimization of the high-
speed diesel to decrease its emission level
*N - Number of ICE simulation sessions at optimization
1,25 1,26 1,27 1,27 1,251,3 1,3
2,52
0
0,5
1
1,5
2
2,5
3
F
Results of optimizing obtained by different methods foranothercombination of the
complex arguments: InjProf, PisBowl, NuzzlDir
o
NOx
o
PMNOx
NOxC
PM
PMCF +=
NuzzlDir:6 di 134
PistBowl: 1
N=76 N=124 N=57 N=88 N=112 N=128 N=85
Method:
Rosenbrok
Method:
Powell
Gradient
method
Method:
Nelder-Mead
Method:
Newton-
Rafson
O
n-coordinates
method
Method:
Davidone-
Flatcher-
Powell
Base
configuration
InjProf: 5
Combination of the complex arguments
Optimum
solution
Scalar
arguments:
CR = 21.7;di = 0.225;
= 17.6;
= 8.2.
Limits:Pz =150 bar;
Pinj = 1501 bar;
ge = 247 g/kWh
NOx=6.11
PM=0.495
NOx=6.9
PM=0.079
NOx=6.6
PM=0.093
NOx=6.6PM=0.0934
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Multiparametric optimization of the high-
speed diesel to decrease its emission level
Comparison between obtained optimum solutions and base ICE
configuration at full load.
Base configuration
F = 2.52
Optimum solution # 1:
F = 1.31
Optimum solution # 2:
F = 1.25
NuzzlDir:
6 0.225 134
PistBowl: # 1
InjProf: 5
Complex
arguments:
NuzzlDir:
5 0.195 146
PistBowl: Base
InjProf: 1
Complex
arguments:
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