electrical discharges in the reverse vortex flow – tornado ... · specific features of the...
TRANSCRIPT
Electrical discharges in the Electrical discharges in the Reverse Vortex Flow Reverse Vortex Flow ––
Tornado DischargesTornado Discharges
ChiranjeevChiranjeev S. S. KalraKalra, Mikhail , Mikhail KossitsynKossitsyn, , KamillaKamillaIskenderovaIskenderova, , AlexandreAlexandre ChirokovChirokov, ,
Young I. Young I. ChoCho, , Alexander Alexander GutsolGutsol, Alexander , Alexander FridmanFridman
ISPCISPC--16 16 TaorminaTaormina 20032003
ScopeScope-- Forward and Reverse Vortex FlowsForward and Reverse Vortex Flows-- MW Discharge in Vortex FlowsMW Discharge in Vortex Flows-- Flame Stabilization in Vortex Flows Flame Stabilization in Vortex Flows -- ICP Discharge in Vortex FlowsICP Discharge in Vortex Flows-- Arc and Gliding Arc in Reverse Vortex FlowArc and Gliding Arc in Reverse Vortex Flow-- Main Peculiarities of Reverse Vortex FlowsMain Peculiarities of Reverse Vortex Flows
Forward Vortex FlowsForward Vortex Flows
Straight flow Direct vortex flow with low rotation
S < 1.4
S = ( ∫ r2 w u dr ) / ( R ∫ r u2 dr )
Ru
S > 1.4
Forward vortex flow with strong rotation
Conventional (Forward Vortex) Method for Conventional (Forward Vortex) Method for Gas Flame StabilizationGas Flame Stabilization
3
1
6
4
52
à
1 – Quartz tube;
2 – Tangential Air Inlet;
4 – Axial Fuel Gas Inlet
6 – Flame Zone
Conventional (Forward Vortex) Conventional (Forward Vortex) Method for ICP StabilizationMethod for ICP Stabilization
1
2
3
4
7
1 - quartz tube;
2 - induction coil;
3 - skin layer;
4 - Inductively Coupled Plasma;
7 - tangential gas feeder for swirl flow formation
Gas Circulation in Tube with SwirlGas Circulation in Tube with Swirl
Typical Flow Pattern in tube near a swirlerTypical Flow Pattern in tube near a swirler11-- tube with closed end; 2 tube with closed end; 2 –– swirler; 3 swirler; 3 –– peripheral vortex flow; peripheral vortex flow; 4 4 –– central zone of reverse flow; 5 central zone of reverse flow; 5 –– face circulation flowface circulation flow
5 4 132
Reverse Vortex FlowReverse Vortex Flow
First gas in
Second gas in
ReverseVortex flow- CircumferentialVelocity component
NozzleFor reverseVortex flow
Gas out
ReverseVortex flow- Axial velocitycomponent
Gas out
Reverse Vortex Stabilization of Reverse Vortex Stabilization of Microwave PlasmaMicrowave Plasma
a b
2
1
3
5
4
6
7
1- quartz tube of microwave plasma torch;
2 -original tangential gas feeder;
3 - hot plasma fluid;
4 - bulk steel plasma-chemical reactor;
5 - steel connecting cone
6 - water-cooled diaphragm;7 - additional tangential gas feeder
Numerical Simulation for 3.5kW Microwave Numerical Simulation for 3.5kW Microwave Plasma Stabilization with AirPlasma Stabilization with Air--Cooling WallsCooling Walls
Numerical Simulation for 3.5kW Microwave Numerical Simulation for 3.5kW Microwave Plasma Stabilization with Adiabatic WallsPlasma Stabilization with Adiabatic Walls
Results of Results of experiments and experiments and Simulation for Simulation for 3.5kW Microwave 3.5kW Microwave Plasma Plasma StabilizationStabilization
J, kJ/g 0
10
20
30
40
50
2’
Wt /Wp ,%
1 2 3 4
3’
3
1
2
FVS – diaphragm
+ reactor
FVS + diaphragm
+ reactor
FVS + diaphragm
- reactor
RVS + reactor
RVS + reactor
Full curves - experiments, broken curves - numerical simulations;
1, 2, 2’ – Forward Vortex Stabilization (FVS)
3 and 3’ – Reverse Vortex Stabilization (RVS)
Reverse vs. Forward Reverse vs. Forward Vortex Methods for Gas Flame Vortex Methods for Gas Flame
StabilizationStabilization
3
1
6
4
52
a b
1 – Quartz tube;
2 – Tangential Air Inlet;
3, 4 – Axial Fuel Gas Inlet
5 – Diaphragm;
6 – Flame Zone
Conventional and Reverse Vortex Conventional and Reverse Vortex Methods for 2kW Flame StabilizationMethods for 2kW Flame Stabilization
α ≈ 1 α ≈ 1.5
Argon ICP, Argon ICP, Plate Power Plate Power –– 16 kW16 kW(a) (a) –– RVS (b) RVS (b) –– FVSFVS
Argon Mass Flow 2.1 g/s 1.4 g/s Argon Mass Flow 2.1 g/s 1.4 g/s Plasma Jet Enthalpy 2.57 kJ/g 2.4 kJ/g Plasma Jet Enthalpy 2.57 kJ/g 2.4 kJ/g
a
b
SelfSelf--consistent Simulation of the Argon RVS ICP consistent Simulation of the Argon RVS ICP
SelfSelf--consistent Simulation of the Argon RVS ICP consistent Simulation of the Argon RVS ICP
Representation of current loop
Current loop method for E - field calculation
Vector potential
)(2
),( 0 kGrRIzrA
πµ
θ =
Experimental and Modeling Results for Experimental and Modeling Results for RVS ICP EfficiencyRVS ICP Efficiency
Efficiency
0
10
20
30
40
50
60
70
0 5 10 15 20 25 30 35 40
Wp
1.4
2.3
3.2
Modeling 1.4
Modeling 2.3
Modeling 3.2
Traditional Gliding ArcTraditional Gliding Arc
Point of DevelopedGliding Arc when Maximum Energy is Transferred
Gas inlet
Reactor
Point of Gliding Arc Ignition
Point of Total Extinction
R
DC Power Supply
Vo
J
l
Electrical scheme of the DC Gliding Arc.
Arc and Gliding Arc in “Tornado”Arc and Gliding Arc in “Tornado”Idea of formationIdea of formation
ReverseVortex flow
Spiral shape,Electrode 1
Electrode 2
Connection wireTo power supply
Plasma reactorPlasma reactor
Arc and Gliding Arc in “Tornado”Arc and Gliding Arc in “Tornado”RealizationRealization
Gliding Arc “Tornado”Gliding Arc “Tornado”Visualization of gas motion near the wallVisualization of gas motion near the wall
Gliding Arc “Tornado”Gliding Arc “Tornado”Electrode 2
Connection wireto power supply
Circular ringElectrode
Gas out
Spiral shapeElectrode
Free end of spiral electrode
Gliding Arc “Tornado”Gliding Arc “Tornado”From the Spiral to the RingFrom the Spiral to the Ring
Gliding Arc “Tornado”Gliding Arc “Tornado”Arc Column with different exposition timeArc Column with different exposition time
Gliding Arc “Tornado”Gliding Arc “Tornado”Evolution between two circular electrodesEvolution between two circular electrodes
Gas flow
Elongation of arc between parallel electrodes but with different gas flow velocities near the two electrodes
Specific Features of the Reverse Vortex FlowsSpecific Features of the Reverse Vortex Flows
Directional heat and mass transfer from the Directional heat and mass transfer from the periphery to the centerperiphery to the centerGasGas--dynamic insulation of the central zonedynamic insulation of the central zoneTrapping of the active gas species in the central zone Trapping of the active gas species in the central zone Convective heat and mass transfer inside the central Convective heat and mass transfer inside the central zone zone –– Method of nonMethod of non--equilibrium (equilibrium (transitional) transitional) plasmaplasma formationformation