numerical simulation of a thermal plasma flow confined by magnetic mirror in a cylindrical reactor
DESCRIPTION
Universidad Simón Bolívar Departamento de Ciencias de lo Materiales Departamento de Física Centro de Ingeniería de Superficies. NUMERICAL SIMULATION OF A THERMAL PLASMA FLOW CONFINED BY MAGNETIC MIRROR IN A CYLINDRICAL REACTOR. Authors: Gabriel Torrente Julio Puerta Norberto Labrador. - PowerPoint PPT PresentationTRANSCRIPT
NUMERICAL SIMULATION OF A THERMAL PLASMA FLOW CONFINED BY MAGNETIC MIRROR IN A CYLINDRICAL
REACTOR
Authors:Gabriel Torrente
Julio PuertaNorberto Labrador
Universidad Simón BolívarDepartamento de Ciencias de lo Materiales
Departamento de Física Centro de Ingeniería de Superficies
ANTECEDENTS:
First Plasma reactor designed and constructed with a grant by FONACIT project of AlN synthesis in a thermal plasma reactor
Thermal Plasma Reactor with Expansion Chamber
RESULTS OF ANTECEDENTS: 8.a
8.b
Problem: Few Thermal Carbonitridation level of Al2O3
Solution for the enhancement of nitridation:1. Increasing the power of the thermal plasma. 2. Increasing the resident time of the powders in the high thermal zones of reactor.
3. Decreasing the thermal energy loss of reactor.
the energy cost of the process increase
the energy cost of the process does not Increase
Then, it is convenient to:1.Design the thermal plasma reactor in fluidized bed for increase the resident time.
2. Confine the thermal plasma flow by magnetic mirror for decrease the energy loss.
New design
Plasma Torch
Magnetic Coils
Graphite tube
Refractory Tube
Wall Reactor
First step
NUMERICAL SIMULATION OF A THERMAL PLASMA FLOW CONFINED BY MAGNETIC MIRROR IN A CYLINDRICAL
REACTOR
Control Volume
The numerical simulation of this thermal axisymmetry plasma jet in magnetic mirror is carried out using two-temperature model to study how changes the electron density and the plasma flux whit the temperature, pressure and with the applied magnetic fields.
Governing Equation
Initial Conditions2
Ag m
A
r ru u
r
0g gv
2
Antg m m gAnt
rT T T T
r
2
2*
11 1
2e
g
T E
T E
Where the cross section impact and average initial temperatura are:
* 8e e
g
Q p mE
e m
gg p m A ef efm C T T V I
Boundary conditions
0
0h
r
u
r
0 00h hr r
v
0h h hr R r R r Ru v
0 0
0e h
r r
T T
r r
In the Central Axel
In the reactor wall
w Ag wr R
T Th T T
Res
e wr RT T
State Equation
1P
RT
10r u
r r z
Continuity Equation
Momentum Conservation Equations (Navier-Stoke Equations)
21 1 2 1
23 r r
u r u rp u u ur J B J B g
z r r z z z r r z r z r r r
2 21 2 2 1 2
3 z z
ru rP u ur J B J B
z r r r z z r r r r r z r r r r
2
1 1z r r z
u r rr J B J B
z r r z z r r r r r r
5 1 5 1
2 2e e e e
B e g e B e g e e e g g eh
T T P Pk n u T k n rv T K K r u v E
z r r z z r r r z r
Energy Conservation Equations
2 3
2e
eh eh e B e hh
mE n k T T
m
Where
3 4 *
3 32
4 lne eei g ei
g e g
V n eV
V m V
2 2
1 1h h h hg g g g g g h h g g eh hp
T T P P u vCp u T Cp rv T K K r u v E E
z r r z z r r r z r r z
Energy transport from the electron to plasma gas
Collision frequency
22 2
2 2 2 2 21 1 1 1z r z r
r z r
h B B h B h BJ E E E
h B h B h h B
rrzr
zz
z EB
BB
h
hE
B
B
h
hE
B
B
h
h
hJ
22
2
2
2
2
2
2 1111
rz
zr E
B
B
h
hE
hE
B
B
h
hJ
222 111
32 2
2
2B gTe B ge
e
m Tne
n n h
Saha Ionization Equation
Ohm Generalized Law
Hypothesis and Data
0 0 02 1 2 2
2cos
2 2 2z v v v
NI NI NI l zB N d N sen sen N
l l l z R
Maxwell Equations
Z rE vB B
r zE B uB
zr vBuBE
Biot-Savart Law
1. Pressure, Heat Capacity Gas (Cpg), Viscosity Gas () and Thermal Conductivity Gas (K) are constants.3. The dissociation energy is neglected. 4. Axial Symmetry 5. Only magnetic field in axial direction 6. Power Plasma Torch = 10,5 KW; mass flow= 13,2 lpm of Nitrogen, Bzmax= 0,3 T, Ionization Energy = 15,4 eV
Results
Axial velocity Profile
Pressure = 1 atmosphere (101325 Pa)
Pressure = 1 Torr (133 Pa)
1
9
17
25
U p
ara
z= 0
U p
ara
z= 1
8
U p
ara
z= 3
6
U p
ara
z= 5
4
U p
ara
z= 7
2
U p
ara
z= 9
0
U p
ara
z= 1
08
U p
ara
z= 1
26
U p
ara
z= 1
44
0
10002000
3000
4000
5000
6000
7000
8000
Velocity (mm/s)
Radius (mm)
Axial Length (mm)
Velocity, 1 atm
7000-8000
6000-7000
5000-6000
4000-5000
3000-4000
2000-3000
1000-2000
0-1000
1
10
19
28
U p
ara
z=
0
U p
ara
z=
15
U p
ara
z=
30
U p
ara
z=
45
U p
ara
z=
60
U p
ara
z=
75
U p
ara
z=
90
U p
ara
z=
10
5
U p
ara
z=
12
0
U p
ara
z=
13
5
U p
ara
z=
15
0
0
1000
2000
3000
4000
5000
6000
7000
8000
Velocity (mm)
Radius (mm)
Axial Lenght (mm)
Velocity, 1 torr
7000-8000
6000-7000
5000-6000
4000-5000
3000-4000
2000-3000
1000-2000
0-1000
Plasma Temperature Profile
1
9
17
25T p
ara
z= 0
T p
ara
z= 1
5
T p
ara
z= 3
0
T p
ara
z= 4
5
T p
ara
z= 6
0
T p
ara
z= 7
5
T p
ara
z= 9
0
T p
ara
z= 1
05
T p
ara
z= 1
20
T p
ara
z= 1
35
T p
ara
z= 1
50
0
1000
2000
3000
4000
5000
6000
Temperature (K)
Radius (mm)
Axial Length (mm)
Plasma Temperature, 1 atm
5000-6000
4000-5000
3000-4000
2000-3000
1000-2000
0-1000
1
10
19
28
T p
ara
z= 0
T p
ara
z= 1
5
T p
ara
z= 3
0
T p
ara
z= 4
5
T p
ara
z= 6
0
T p
ara
z= 7
5
T p
ara
z= 9
0
T p
ara
z= 1
05
T p
ara
z= 1
20
T p
ara
z= 1
35
T p
ara
z= 1
50
0
1000
2000
3000
4000
5000
6000
Temperature (K)
Radius (mm)
Axial Length (mm)
Plasma Temperature, 1 torr
5000-6000
4000-5000
3000-4000
2000-3000
1000-2000
0-1000
Pressure = 1 atmosphere (101325 Pa)
Pressure = 1 Torr (133 Pa)
Electronic Temperature Profile
1
10
19
28
Te
para
z=
0
Te
para
z=
15
Te
para
z=
30
Te
para
z=
45
Te
para
z=
60
Te
para
z=
75
Te
para
z=
90
Te
para
z=
105
Te
para
z=
120
Te
para
z=
135
Te
para
z=
150
0
1000
2000
3000
4000
5000
6000
Electronic Temperature (K)
Radius (mm)
Axial Lenght (mm)
Electronic Temperatue, 1 atm
5000-6000
4000-5000
3000-4000
2000-3000
1000-2000
0-1000
1
11
21
31
Te
para
z=
0
Te
para
z=
15
Te
para
z=
30
Te
para
z=
45
Te
para
z=
60
Te
para
z=
75
Te
para
z=
90
Te
para
z=
105
Te
para
z=
120
Te
para
z=
135
Te
para
z=
150
0
1000
2000
3000
4000
5000
6000
Electronic Temperature (K)
Radius (mm)
Axial Lenght (mm)
Electronic Temperature, 1 torr
5000-6000
4000-5000
3000-4000
2000-3000
1000-2000
0-1000
Pressure = 1 atmosphere (101325 Pa)
Pressure = 1 Torr (133 Pa)
Density Plasma Profile
1
12
23
Dg
para
z=
0
Dg
para
z=
15
Dg
para
z=
30
Dg
para
z=
45
Dg
para
z=
60
Dg
para
z=
75
Dg
para
z=
90
Dg
para
z=
105
Dg
para
z=
120
Dg
para
z=
135
Dg
para
z=
150
0,00E+00
2,00E-11
4,00E-11
6,00E-11
8,00E-11
1,00E-10
1,20E-10
1,40E-10
Gas Density (g/mm3)
Radius (mm)
Axial Lenght (mm)
Plasma Density, 1 atm
1,20E-10-1,40E-10
1,00E-10-1,20E-10
8,00E-11-1,00E-10
6,00E-11-8,00E-11
4,00E-11-6,00E-11
2,00E-11-4,00E-11
0,00E+00-2,00E-11
1
12
23
Dg
para
z=
0
Dg
para
z=
12
Dg
para
z=
24
Dg
para
z=
36
Dg
para
z=
48
Dg
para
z=
60
Dg
para
z=
72
Dg
para
z=
84
Dg
para
z=
96
Dg
para
z=
108
Dg
para
z=
120
Dg
para
z=
132
Dg
para
z=
144
0,00E+00
2,00E-14
4,00E-14
6,00E-14
8,00E-14
1,00E-13
1,20E-13
1,40E-13
1,60E-13
Density gas (g/mm3)
Radius (mm)
Axial Lenght (mm)
Density Gas, 1 torr
1,40E-13-1,60E-13
1,20E-13-1,40E-13
1,00E-13-1,20E-13
8,00E-14-1,00E-13
6,00E-14-8,00E-14
4,00E-14-6,00E-14
2,00E-14-4,00E-14
0,00E+00-2,00E-14
Pressure = 1 atmosphere (101325 Pa)
Pressure = 1 Torr (133 Pa)
Electronic Density Profile
1
9
17
25
De
para
z=
3
De
para
z=
18
De
para
z=
33
De
para
z=
48
De
para
z=
63
De
para
z=
78
De
para
z=
93
De
para
z=
108
De
para
z=
123
De
para
z=
138
0,00E+00
1,00E+08
2,00E+08
3,00E+08
4,00E+08
5,00E+08
6,00E+08
7,00E+08
8,00E+08
9,00E+08
Electronic Density (#e/mm3)
Radius (mm)
Axial Lenght (mm)
Electronic Density, 1 atm
800000000-900000000
700000000-800000000
600000000-700000000
500000000-600000000
400000000-500000000
300000000-400000000
200000000-300000000
100000000-200000000
0-100000000
1
11
21
31
De
para
z=
3
De
para
z=
18
De
para
z=
33
De
para
z=
48
De
para
z=
63
De
para
z=
78
De
para
z=
93
De
para
z=
108
De
para
z=
123
De
para
z=
138
0,00E+00
5,00E+06
1,00E+07
1,50E+07
2,00E+07
2,50E+07
3,00E+07
3,50E+07
Electronic Density (#e/mm3)
Radius (mm)
Axial Lenght (mm)
Electronic Density, 1 torr
30000000-35000000
25000000-30000000
20000000-25000000
15000000-20000000
10000000-15000000
5000000-10000000
0-5000000
Pressure = 1 atmosphere (101325 Pa)
Pressure = 1 Torr (133 Pa)
Z ionization Profile
1
11
21
31
Zio
n pa
ra z
= 3
Zio
n pa
ra z
= 1
8
Zio
n pa
ra z
= 3
3
Zio
n pa
ra z
= 4
8
Zio
n pa
ra z
= 6
3
Zio
n pa
ra z
= 7
8
Zio
n pa
ra z
= 9
3
Zio
n pa
ra z
= 1
08
Zio
n pa
ra z
= 1
23
Zio
n pa
ra z
= 1
38
0,00E+00
5,00E-07
1,00E-06
1,50E-06
2,00E-06
2,50E-06
3,00E-06
3,50E-06
4,00E-06
Ionization
Radius (mm)
Axial Length (mm)
Ionization, 1 atm
3,50E-06-4,00E-06
3,00E-06-3,50E-06
2,50E-06-3,00E-06
2,00E-06-2,50E-06
1,50E-06-2,00E-06
1,00E-06-1,50E-06
5,00E-07-1,00E-06
0,00E+00-5,00E-07
1
11
21
31
Zio
n pa
ra z
= 3
Zio
n pa
ra z
= 1
8
Zio
n pa
ra z
= 3
3
Zio
n pa
ra z
= 4
8
Zio
n pa
ra z
= 6
3
Zio
n pa
ra z
= 7
8
Zio
n pa
ra z
= 9
3
Zio
n pa
ra z
= 1
08
Zio
n pa
ra z
= 1
23
Zio
n pa
ra z
= 1
38
0,00E+00
2,00E-05
4,00E-05
6,00E-05
8,00E-05
1,00E-04
1,20E-04
Ionization
Radius (mm)
Axial Lenght (mm)
Ionization, 1 torr
1,00E-04-1,20E-04
8,00E-05-1,00E-04
6,00E-05-8,00E-05
4,00E-05-6,00E-05
2,00E-05-4,00E-05
0,00E+00-2,00E-05
Pressure = 1 atmosphere (101325 Pa)
Pressure = 1 Torr (133 Pa)
Average Z ionization
0,00E+00
5,00E-06
1,00E-05
1,50E-05
2,00E-05
2,50E-05
3 23 43 63 83 103 123 143 163
Axial Lenght (mm)
Ioni
zatio
n
Average Z (1atm)
Average Z (1 torr)50 mm
Plasma Torch
Conclusions
The axial velocity has few changed with the pressure.
The Plasma Temperature has few changed with the pressure.
The electronic temperature has few increasing with the vacuum
The Plasma and Electronic densities decreases with the vacuum.
Z ionization increases with the vacuum.