Progress in Excess Power Production byLaser Triggering

V. Violante1, M. Bertolotti2, E. Castagna2, I. Dardik5, M.McKubre4, S. Moretti 2,S.Lesin5, C. Sibilia2, F.Sarto3, F.Tanzella4, T. Zilov 5

(1) ENEA Frascati Research Center Frascati (Italy )(2) University of Rome La Sapienza Dpt. Energetica Rome (Italy)(3) ENEA Casaccia Research Center Rome (Italy)(4) SRI International Menlo Park CA (USA)(5) Energetics (USA-Israel)

ICCF12 Yokohama 27-11/2-12-05

Index

• Previous results• New cell concept for isoperibolic calorimetry with trigger• Modelling & engineering• Calibration• Results• Conclusions

Evolution of the input and output power, last300 hr under laser irradiation (P-polarization)

312 336 360

Time s

200000 400000 600000

Pin

and

Pou

t-W

-

150000

350000

550000

750000

Excess of Energy and Power in Laser4 Experiment

En

ergy

Inan

dE

nerg

yO

ut-

J-

0.70

1.20

1.70

2.20

2.70

3.20

Input Energy

OutputEnergy

OutputPower

Input Power

E=30 kJ

Laser 4 experiment

Previous Results

Experiments

4-H

eA

tom

s

4-He Mass Spectrometry for Laser Triggered Experiments

1.40E+16

1.00E+16

0.40E+16

Laser-2 Laser-4Laser-3

Expected values

23.5 kJ

3.40 kJ

30.0 kJ1.20E+16

0.80E+16

0.60E+16

0.20E+16

Background

4He Production

Pd anodic erosion

III Esp LiOD, 5-07-2004

2,5

2,6

2,7

2,8

2,9

3

3,1

3,2

3,3

3,4

3,5

93 98 103 108

Time (h)

I cell(A)P in (W)Pres (bar)R\Ro correttaPout

Laser Off

Laser on-off effect

Laser off

P pol.

Improvement of the Cell

Old cell

Sensitivity

296297298299300301302303304

0 0,2 0,4 0,6 0,8 1 1,2

P -w-

T -K-

S calc

S exp

Old Cell Temperature vs Power

Model

Experiment

Average temperature of the electrolyte vs power

Double Structure New Cell for Laser Experiments

zTV

yTV

xTVc

tTcQTgradKdiv zyxpp

)(

ThermalThermal AnalysisAnalysis

Heat transfer equation

Boundary conditions

aTThnTK

Assumptions:

• 3D transient

• isotropic (Kx=Ky=Kz)

• Steady state boundary conditions (thermostatic box) Tamb = cost.(t)

• Radiative heat exchange negligible

(convective heat exchange mechanism)

HydrogenHydrogen BubblesBubbles at theat the CathodeCathode

Gas velocity VH2 is calculated by means of the currentdensity

Gas flow rate forunit area nF

JK

10004,22

Total gas flow rate z

zKLdzKLW0

zK

LW

AW

zgasV

)(Gas velocity

δ

L

dzh

(cm/s)

(cm3/s)

(cm/s)

Pd foil

BzH

AzOH VV

22093,0

One fluid is moved by the otherhaving different density and viscosity

Gas H2

Electrolyte

121

21

0

BA

B

B

BA

A

A

xB

z

Az

VV

093.07

120

BA

B

Bz

Az

VV

Liquid-GasInterface

LiquidLiquid--GasGas InterfaceInterface VelocityVelocity

BzV

AzV0

Vel

oci

tydi

stri

buti

on

The electrolyte interface velocity iscalculated by the average gas velocity

Assumptions

EquationsEquations

density and viscosity are constant

steady state

axial symmetry

negligible effect of pressure and mass

01

rzv

rrr

01

z

v

r

vv

rzr

r

Motion Equation

Continuity equation

Iterative procedure for velocity field calculation

solving the equation of motion with the boundary conditionsvz=V0z r=a ; vz=0 r=R

step1: Equation of motion

Ra

roV

RaoV

Rzvln

ln

lnln

Step 2: Continuity equationby replacing the vz calculated at step 1 and by solving thecontinuity equation with the condition of zero flow rate in theradial direction

Ra

RrrK

rC

rv R

r ln4

1ln2)( 1

2

222

1 lnln

41

aRaRaRaK

C R

Step 3: Continuity equationBy replacing vr calculated at step 2 and by solving thecontinuity equation with the condition of zero flow rate in axialdirection

zz CRr

KzzrVV 12 ln),(

Ra

aRRazKC z

2

22 ln221

21

FEMFEM DomainDomain

X

-7.6

7.6

Y

7. 6

-7.6

Z0.

14.

3

Domain estrusionCAD 2D

X

-3. -2. -1. 0. 1. 2. 3.

Z

4.5

5.

5.5

6.

6.5

7.

7.5

8.

8.5

9. VVon y=0zoom(-3,4.8,6,4)

8.007.507.006.506.005.505.004.504.003.503.002.502.001.501.000.500.00

Scale =E-3

MeshMesh andand VelocityVelocity FieldField

Mesh 3D

1212

X

-6. -3. 0. 3. 6.

Z

0.

3.

6.

9.

12.

15.

x,zon y=0

Velocity field due to bubbles

Thermal Analysis

Y

-6. -3. 0. 3. 6.

Z

0.

3.

6.

9.

12.

15.

a

bc d

ef

g

h

i

j

l

n

o

p

q

o

x

314.9314.0313.0312.0311.0310.0309.0308.0307.0306.0305.0304.0303.0302.0301.0300.0299.0298.0297.7

TemponX=0

maxq :p :o :n :m:l :k:j :i :h :g :f :e :d :c :b :a :min

Isotherms axial plane

Distance

0. 1. 2. 3. 4. 5. 6. 7. 8.

Tem

p

300.

303.

306.

309.

312.

315.

a

a

aa

a

a

^ ^ ^^ ^^ ^^ ^^ ^ ^

a

a

a

a

^ ^ ^ ^ ^ ^ ^ ^

a

a

^ ^̂ ^^̂^ ^ ^ ^1 2

1

2

Temperature profile along 1-2

T e4

0. 1. 2. 3. 4. 5.

Tem

p

298.

299.

300.

301.

302.

303.

304.

a

HISTORY

1: Temp

Temperature evolution

100 mW inputincreasing

CellCell

Electricconnections

Pt100Thermometers

ExperimentalExperimental System Set upSystem Set up

Thermostatic bathMeasurementinstruments

Thermostaticbox

Computer

Thermostatic bath

Power supply

Thermostatic System

Comparison between Experimental Data and Model

Curva di calibrazione

0

5

10

15

20

25

30

35

40

45

0 1 2 3 4 5

Potenza (Watt)

Tem

pe

ratu

ra(°

C)

Curva sperimentale

Simulazione

Calibration and Model

Power - W

Model

Experiment

Tem

pera

ture

-°C

-

Comparison between calibration data and model

ExperimentModel

Curve di calibrazione

0

10

20

30

40

50

60

70

80

90

0 2 4 6 8 10 12

P (W)

T(°

C)

T simulazione CON convezioneT SperimentaleT1 SENZA convezione

Experiment

ModelModel withoutfluid-dynamics

Comparison between experimental data and model,with and without fluid-dynamics

Model with fluiddynamicsExperimentModel no fluiddynamics

Models and experiment

Laser 5 Experiment: Calorimetric Results

Excess power during laser triggering (HeNe laser)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 50 100 150 200 250 300

P in (W)Pout(W)

Current inversion

Time hr

49 kJ Excess energy

R/R0≤1.74

Laser on

Excess Power Life hr

0

50 100 150 200

En

ergy

Exc

-J-

0

10

20

30

40

50Excess Energy vs Excess Power Life

Laser-5

Laser-2

Laser-4

Excess energy vs excess power life time

Excess energy vs experiment elapsed time

Elapsed Time hr

50 100 150 200 250 300 350 400 450

Ene

rgy

Exc

-J-

0

10

20

30

40

50Energy Excess vs Total Elapsed Time

Laser-5

Laser-2Laser-4

ConclusionsConclusions

The improvement of the calorimeter design allowed toThe improvement of the calorimeter design allowed toobtain a satisfactory agreement between model andobtain a satisfactory agreement between model andexperiment.experiment.

Laser trigger gave significant reproducibility:Laser trigger gave significant reproducibility:excess power in 4 out of 5 experimentsexcess power in 4 out of 5 experiments

The amplitude of the effect is not yet under controlThe amplitude of the effect is not yet under controleven though high loading is almost always achieved.even though high loading is almost always achieved.

MaterialMaterial studiesstudies are in progressare in progress toto identifyidentify and controland controlthe status of the systemthe status of the system producingproducing enhancedenhanced valuesvalues ofofthethe signalsignal..