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Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
TRANSIENT CAPILLARY PUMPED LOOPMODELLING WITH
ESATAN/FHTS AND SINDA/FLUINT
Christian PUILLET, Hugo MAMEDE FIGUEIREDO
C.N.E.S.
Département Thermique
DTS / AE / MTE / TH18, avenue Edouard Belin, F-31401 TOULOUSE cedex 04, France
2
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
CONTENTS
• CAPILLARY PUMPED LOOP PRESENTATION
• OBJECTIVES
• MODEL PRESENTATION
• MODELS WITH MECHANICAL PUMPS• MODELS WITH CAPILLARY PUMPS
• TEMPERATURE RESULTS
• INFLUENCE OF NUMBER OF NODES
• ANALYSIS
• CONCLUSION
3
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
CNES/MMS 5kW AMMONIA CAPILLARY PUMPED LOOP
DEVELOPPED UNDER CNESCO-FUNDED R&D CONTRACT(1993-1994)
5 CAPILLARY EVAPORATORS 4 CONDENSERS (IN PARALLEL)1 VAPOUR LINE1 LIQUID LINE1 TWO-PHASE RESERVOIR
4
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
CAPILLARY EVAPORATOR PRINCIPLE
LIQUID
10 to 40 mm
VAPOURCHANNEL
POROUSMATERIAL
LIQUIDINLET
VAPOUROUTLET
POROUS MATERIAL
0.05 to 0.5m
HEAT
5
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
OBJECTIVES
• START-UP MODEL OF 1st EVAPORATOR FROM FULLY FLOADED LOOP. DEVELOPPED IN MID 90’s USING MECHANICAL PUMPS AND VALVES.
• MODEL CONVERTED IN ESATAN/FHTS IN 99, PRESENTED AT 13th EWTES.
• REMAINING ISSUES :• USE OF FHTS CAPILLARY ELEMENTS• COMPARISON WITH SINDA/FLUINT
• OBJECTIVE :• TO EVALUATE ESATAN/FHTS CAPILLARY ELEMENTS• TO GET A MODEL SIMPLER AND MORE PRACTICAL TO USE
• MAINS POINTS :• FLUID TIME CONSTANTS (little solid inertia)• EVAPORATORS CLEARING (EVAP. 2 TO 5)• VAPOUR FRONT DISPLACEMENT
6
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
MODEL
MECH. EVAPORATORS
EVAPISOL.
ISOLATOR
CAPIL. EVAPORATORS
CAPILLARYEVAPORATOR
Pressuredrop EVAP.
OUTLET
VAPOUR LINE• Convective coupling with air• Global pressure drop
CONDENSER• Cooling loop @ 0°C
LIQUID LINE• Convective coupling with air
PRESSURISER• Heater with prop. regulation
MODEL GEOMETRY CORRECTEDMECHANICAL PUMPS MODELLING AS CLOSE AS POSSIBLE TO CAPILLARY PUMPS
7
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
Débit massique Evaporateur1
-5,00E-03
0,00E+00
5,00E-03
1,00E-02
1,50E-02
2,00E-02
0,00E+00 1,00E+01 2,00E+01 3,00E+01 4,00E+01 5,00E+01
Temps (s)
Déb
it m
assi
qu
e (k
g/s
)
FR5002
FR5006
FR5007
FR5008
FR5009
FR5011
FR5012
Arrivée du front vapeurà l'élément VANNE2 (FR5011)
Arrivée du front vapeurà l'élément VANNE 1 (FR5009)
Arrivée du front vapeurà l'élément SORTIE (FR5012)
Début de production vapeurdans l'élément TUBE (FR5008)
Mass flow rate evaporator 1
SINDA/FLUINT WITH MECHANICAL PUMPS
PRESSURE OSCILLATIONSCAUSED BY VAPOUR FRONTENTERING EACH FLUID NODE
=> HIGH MASS FLOW RATE& PRESSURE PEAKS
Saut de pression pompe et conduite principale
-5,0E+02
0,0E+00
5,0E+02
1,0E+03
1,5E+03
2,0E+03
2,5E+03
3,0E+03
3,5E+03
4,0E+03
0 100 200 300 400
Temps (s)
Sau
t d
e p
ress
ion
(P
a)
PL1005-PL1004 - Pompe
PL1009-PL1321 - Conduite principale
Loop pressure drop
8
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
Débit massique Evaporateur1
-5,00E-03
0,00E+00
5,00E-03
1,00E-02
1,50E-02
2,00E-02
0,00E+00 1,00E+01 2,00E+01 3,00E+01 4,00E+01 5,00E+01
Temps (s)
Déb
it m
assi
qu
e (k
g/s
) FR5002 - ISOL
FR5007 - Pompe - Tube
FR5008 - Tube - Vanne 1
FR5009 - Vanne 1 - 2
FR5011 - Vanne 2 - Sortie 1
FR5012 - Sortie 1Saut de pression pompe et conduite principale
-5,0E+02
0,0E+00
5,0E+02
1,0E+03
1,5E+03
2,0E+03
2,5E+03
3,0E+03
3,5E+03
4,0E+03
0 100 200 300 400
Temps (s)
Sau
t d
e p
ress
ion
(P
a)
PL1005-PL1004 - Pompe
PL1009-PL1321 - Conduite principale
ESATAN/FHTS WITH MECHANICAL PUMPS
SAME BEHAVIOUR
SMOOTHER
Loop pressure drop
Mass flow rate Evaporator 1
9
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
SINDA/FLUINT WITH CAPILLARY PUMPS
Débit massique Evaporateur1
-5,00E-03
0,00E+00
5,00E-03
1,00E-02
1,50E-02
2,00E-02
0,00E+00 1,00E+01 2,00E+01 3,00E+01 4,00E+01 5,00E+01
Temps (s)
Déb
it m
assi
qu
e (k
g/s
)
ISOL
Après injection de puissance
Cannelures - Vanne 1
Vanne 1 - 2
Vanne 2 - Sortie 1
Sortie 1
Avant injection de puissance
Saut de pression pompe et conduite principale
-3,5E+03
-2,5E+03
-1,5E+03
-5,0E+02
5,0E+02
1,5E+03
2,5E+03
3,5E+03
0 100 200 300 400 500 600 700
Temps (s)
Sau
t d
e p
ress
ion
(P
a)Evaporateur capillaire
Conduite principale
Mass flow rate evaporator 1
Loop pressure drop
OSCILLATIONS MORE SEVERETHAN WITH MECHANICAL PUMPS
SAME GLOBAL BEHAVIOUR
(blue line : cap. evap. plotted as negative)
10
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
ESATAN/FHTS WITH CAPILLARY PUMPS
Débit massique Evaporateur1
-5,00E-03
0,00E+00
5,00E-03
1,00E-02
1,50E-02
2,00E-02
2,50E-02
3,00E-02
0,00E+00 1,00E+01 2,00E+01 3,00E+01 4,00E+01 5,00E+01
Temps (s)
Déb
it m
assi
qu
e (k
g/s
) FR5002 - ISOL
FR5007 - Pompe - Tube
FR5008 - Tube - Vanne 1
FR5009 - Vanne 1 - 2
FR5011 - Vanne 2 - Sortie 1
FR5012 - Sortie 1
Saut de pression pompe et conduite principale
-5,0E+02
0,0E+00
5,0E+02
1,0E+03
1,5E+03
2,0E+03
2,5E+03
3,0E+03
3,5E+03
4,0E+03
0 100 200 300 400
Temps (s)
Sau
t d
e p
ress
ion
(P
a)
Evaporateur capillaire
Conduite principale
SAME CONCLUSION AS WITHSINDA/FLUINT
Mass flow rate evaporator 1
Loop pressure drop
11
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
TEMPERATURE (MECHANICAL PUMPS)
Comparaison des Température à divers endroits de la boucle
0,0E+00
5,0E+00
1,0E+01
1,5E+01
2,0E+01
2,5E+01
3,0E+01
3,5E+01
0 100 200 300 400 500 600 700 800 900
Temps (s)
Tem
pér
atu
re (
°C)
FHTS - Fin tube vapeur
FHTS- Début tube liquide
FHTS - Fin tube liquide
Essais - Fin tube vapeur
Essais - Début tube liquide
Essais - Fin tube liquide
FLUINT - Fin tube vapeur
FLUINT - Début tube liquide
FLUINT - Fin tube liquide
VAPOUR FRONT MOVES TOO FAST
Temperature : end of vapour line, beginning & end of liquid lineresults vs. test measurement
end of vapour (test)
end of liquid (test)
beg. of liquid (test)
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Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
TEMPERATURE ESATAN/FHTSmechanical vs. capillary
Température à divers endroits de la boucle
0,0E+00
5,0E+00
1,0E+01
1,5E+01
2,0E+01
2,5E+01
3,0E+01
3,5E+01
0 100 200 300 400 500 600 700
Temps (s)
Tem
pér
atu
re (
°C)
FHTS Capil - Fin tube vapeur
FHTS Capil - Début tube liquide
FHTS Capil- Fin tube liquide
FHTS Non capil - Fin tube vapeur
FHTS Non capil - Début tube liquide
FHTS Non capil - Fin tube liquide
Temperature : end of vapour line, beginning & end of liquid line
THE VAPOUR FRONT MOVES EVEN FASTER WITH CAPILLARY PUMPS
(NO CONTROL ON MASS FLOW RATE FOR FIRST BUBBLES GENERATION INTHE CAPILLARY PUMP)
mech.
capil.
13
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
INFLUENCE OF NUMBER OF NODESQ < 0
Q < 0
Isolator
INITIAL STEADY-STATE :
THEN THE HEAT EXTRACTION IS REMOVED ON THE UPPER LINE
FINAL STEADY-STATE :
Q < 0
INFLUENCE OF NUMBER OF NODES ON MASS FLOW RATE WITHIN ISOLATOR ?
vapour liquid
14
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
CONVERGENCE IN TIME STEPMASS FLOW RATE IN ISOLATOR
CPU: 0.02 s / 42 s, 0.004 s / 81 s, 0.0008 s / 146 s
15
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
INFLUENCE OF NUMBER OF NODES
1) CONVERGENCE REQUIRESA VERY HIGH NUMBER
OF NODES
2) FRONT MOVES FASTER
CPU: 16 / 1mn21s, 28 / 2mn19s, 52 / 5mn12s, 100 / 10mn6s, 196 / 21mn4s, 388 / 60mn6s
16
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
ANALYSIS
• ABILITY TO SOLVE START-UP FROM FULLY FLOADED LOOP WITH PARALLEL LINES
• TYPICAL CPU TIME : ESATAN/FHTS SINDA/FLUINT MECH. PUMPS 120 mn 10 mn CAPIL. PUMPS 180 mn 50 mn
• LARGE INFLUENCE OF PRESSURE DROPS ON RESULTS• NUMERICAL DIFFICULTIES TO SOLVE IF VAPOUR FRONT IS BLOCKED BY EVAPORATORS BEFORE IT REACHES THE CONDENSER• VERY SMALL TIME STEPS
• HOWEVER, QUESTIONS ABOUT COHERENCE OF PHYSICS MODELLED WITH REALITY• LUMPED PARAMETER METHOD• HOMOGENEOUS MODEL
• => MORE ANALYTICAL AND EXPERIMENTAL WORK WOULD BE REQUIRED ON A SIMPLER LOOP (1 EVAPORATOR , 1 CONDENSER) TO GET CONFIRMATION
17
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
CONCLUSION
THE ESATAN/FHTS CAPILLARY ELEMENTS WORK PROPERLY WITHINTHE LIMITATION OF THE PHYSICAL MODEL
CAPILLARY ELEMENTS SIMPLIFY THE WORK OF THE USER
THE MODELLING OF START-UP IS POSSIBLE
HOWEVER, MAYBE IT SHOULD BE LIMITED TO MODELS IN WHICHFLUID TRANSIENT IS NEGLIGIBLE
• MORE QUESTIONS THAN ANSWERS AT THE END OF THE WORK
• DOUBT ON THE POSSIBILITY TO GET A SIMPLER AND MORE PRACTICAL MODEL FOR FLUID START-UP
18
Division Mécanique Thermique Energétique
15th European Workshop on Thermal & ECLS Software - 9-10 October 2001 - Noordwijk, NL
TRANSIENT CAPILLARY PUMPED LOOPMODELLING WITH
ESATAN/FHTS AND SINDA/FLUINT
Christian PUILLET, Hugo MAMEDE FIGUEIREDO
C.N.E.S.
Département Thermique
DTS / AE / MTE / TH18, avenue Edouard Belin, F-31401 TOULOUSE cedex 04, France