32
1 EHP grooved Heat Pipe 0-G Heat Experiment and 1-G test simulation EHP Paris SFT « Contrôle thermique des composants électroniques par voie diphasique » Stephane Van Oost Paris 1th December 2005

EHP grooved Heat Pipe 0-G Heat Experiment and 1-G test ... · Evaporation and condensation heat transfer ... 8 HEAT Maximum heat transport capability ... “Heat Experiment” on

  • Upload
    doannhi

  • View
    232

  • Download
    0

Embed Size (px)

Citation preview

1

EHP grooved Heat Pipe 0-G Heat Experiment

and 1-G test simulation

EHP

Paris SFT « Contrôle thermique des composants

électroniques par voie diphasique »Stephane Van Oost Paris 1th December 2005

2

Table of content :

0G Test of AG110 Heat Pipe “HEAT experiment”Objectives description

0G - 1G Static – 1G Rotating AG110 Heat Pipe test results Maximum Heat transport capabilityEvaporation and condensation heat transfer

1G Static – 1G Rotating AG200 Heat Pipe test results Maximum Heat transport capabilityEvaporation and condensation heat transfer

0G – 1G Rotating AG110 Thermal simulationTemperature map around the profileFluid distribution based on temperature map

Conclusions

3

0G Characterization of the heat transfer performances of a std EHP aluminium re-entrant grooved Heat Pipe by deriving the maximum sustainable heat flux and heat transfer coefficients in three functioning modes.

Run 1

Run 2

Run 3

Validation and optimization of the existing mathematical hydraulic models and test methods for the new generation of High Performances Heat Pipes.

Heat ExperimentMain Scientific Objectifs :

4

0-G Heat experiment Box hardware

Launched with a Russian Progress launcher “13P” on the 29 January 2004.

The Payload was operated in the Microgravity Science Glovebox(MSG)

5

NASA - MSFC : MSG accommodation

6

AG110 small heat pipe diameter 11 mm

- Maximum Heat Transport capability

- Heat transfer performances at evaporation and condensation interfaces

7

Run 1 configuration :

Run 2 configuration :

Run 3 configuration :

8

HEAT Maximum heat transport capability “Qmax” synthesis 1G / 0G / Rotating

Qmax summary

020406080

100120140

1G-Ushapecorrected

0G Ushapecorrected

1Grot-straight

Environment type

Qm

ax [W

m]

Run1Run2Run3

9

0G RUN2 configuration (bottom / bottom)

GMT250_mode1_run2

0

10

20

30

40

50

60

70

1 83 165

247

329

411

493

575

657

739

821

903

985

1067

1149

1231

1313

1395

1477

1559

1641

1723

1805

1887

1969

2051

2133

2215

2297

2379

2461

2543

2625

2707

2789

2871

2953

3035

3117

0

20

40

60

80

100

120

140

H55_HT_TS3H56_HT_TS6H57_HT_TS13H58_HT_TS14H59_HT_TS18H60_HT_TS21Mean powerInput power

Evaporator Area

Condenser Area

Evaporator Area

Condenser Area

Ptotal = 108W x 1.065m (effective length) = 115Wm @ +45°C with 2 bendings 90° (5 x OD)

10

EHP Preliminary Heat Pipe Rotating test benchSpeed: 18 rpm

11

1G-RotatingRUN2 configuration

Ptotal = 116W x 1.065m = 123Wm @ +40°C

12

fluid distribution in 0G and in 1G rotational

Liquid return by capillary actionEVAPORATORCONDENSOR

Liquid homogeneously distributed between grooves

13

1G staticRUN2 configuration (bottom / bottom)

HEAT- montage sur base plate Chauffage par en-dessous P/N : 11A10-01-10001 S/N : S001

20

25

30

35

40

45

50

55

60

65

425 445 465 485 505 525 545 565 585 605 625 645

acq. (1acq.= 20s)

T (°

C)

-20,00

0,00

20,00

40,00

60,00

80,00

100,00

120,00

140,00

160,00

TC1 (°C)

TC2 (°C)

TC3 (°C)

TC4 (°C)

TC6 (°C)

TC7 (°C)

TC8 (°C)

TC9 (°C)

TC10 (°C)

TC11 (°C)

TC12 (°C)

TC13 (°C)

TC14 (°C)

TC15 (°C)

TC16 (°C)

TC17 (°C)

TC18 (°C)

TC19 (°C)

TC21 (°C)

TC23 (°C)

TC24 (°C)

TC25 (°C)

TC26 (°C)

Ptotal = 107W x 1.065m (effective length) = 114Wm @ +40°C with 2 bendings 90° (5 x OD)

Evaporator Area

Condenser Area

Evaporator Area

Condenser Area

14

Heat pipe under 1G static

Liquid return by capillary action and puddle effect

Liquid Nonhomogeneously distributed between grooves Large impacts with large diameter

in 1-g condition the liquid plug become a liquid puddle (stratification)

the location of the heater and cooler have an impact on the heat transfer coefficient at evaporator level and at condenser level

15

Heat pipe 1G Static, 1G rotating and 0G impacts• 1G – 0G environment presents a different of temperature distributionmeaning different liquid distribution inside the profile and grooves => different physical behaviour are applicable (puddle effect & performances).

• 1G rotational tests provide similar temperature distribution meaning similar liquid distribution than in 0G => same physical behaviour can be considered. Centrifugal influence on hydraulic performances has been addressed.

• For the EHP AG110 HP @+20°C, with less than 18 rpm the results are:• Capillary pressure : 53 Pa• Centrifugal acceleration effect (radial) : 0,015 [m/s²] < 9,81[m/s²]• Groove static gravity pressure effect (axial, 1m) : 13,4 Pa

• Centrifugal pressure effect on groove (axial, 1m) : 0,03 Pa

16

Heat transport and heat transfer coefficients under 1G-Rotating Heat Pipe

With respect to two different rotating speed

56 [tr/min] 18 [tr/min]Kevap [W/°C.m²] 7400 7500

Kcond [W/°C.m²] 4150 4500

MeasuredHeat transport capacity [Wm]

141 Wm / 152 Wm at 20°C 147 Wm at 20°C

Predicted 0G model [Wm]

141 Wm at 20°C

17

Heat transfer coefficients : 1G- RUN 1

0

20

40

60

80

100

120

140

0 50 100 150 200 250

Time [min]

T [°

C] &

P[W

]

0

1000

2000

3000

4000

5000

6000

7000

8000

K [W

/m²K

]

TM evap (TC3,6,8,10)Tm Adia (°C)Tm Cond (°C)P Evap Eff (W)K Evap (W/m².K)K Cond (W/m².K)

Condenser +/- 2000 Wm²K

Evaporator +/- 4500 Wm²K

18

Heat transfer coefficients : 0G- RUN 1

0

20

40

60

80

100

120

750 1250 1750 2250 2750 3250

Time [s]

T [°

C] &

P[W

]

0

2000

4000

6000

8000

10000

12000

K [W

/m²K

]

Power meanMean evaporator top (TS3,TS6,TS8)Mean evaporator bot (TS4,TS7,TS9)Mean adia (12,13)Mean condensor saddles (15,17,19)Evap heat transfert coeff (DT top-adia)Condensor heat transfert coeff

Condenser +/- 3500 Wm²K

Evaporator +/- 8000 Wm²K

19

Heat transfer coefficients : 1G-Rotating RUN 1

Condenser level +/- 4000 Wm²K

Evaporator level +/- 7500 Wm²K

20

HEAT transfer coefficients 1G with various configurations

0

10002000

3000

4000

50006000

7000

8000

900010000

11000

12000

1300014000

15000

25 50 75 100 125

POWER (W)

HEA

T TR

AN

SFER

(W/m

²K)

EVAPTOPheatBOTcool

CONDTOPheatBOTcool

EVAPSIDEheatSIDEcool

CONDSIDEheatSIDEcool

EVAPBOTheatTOPcool

CONDBOTheatTOPcool

EVAPBOTheatBOTcool

CONDTOPheatBOTcool

Independent of the test configuration for

Q ≤ 50% of Qmax

Condenser level

Evaporator level

21

Heat transfer coefficients : 0G - 1G- Static and 1G Rotating for small heat pipe diameter

EHP “HEAT” AG110, 11 mm diameter

1 G Static 1G Static 1G Static 1G Static Rotating0-G

50% Qmax50% Qmax

50% Qmax50% Qmax 70%Qmax 70%Qma

heating

cooling

Kevap(W/(M².K))

9300 9700 9100 10000 7500 8000

Kcond(W/(M².K))

2100 4300 2100 3800 4500 3550

22

AG200 large heat pipe diameter 20 mm

1G tests conditions impact

- Maximum Heat Transport capability

- Heat transfer performances at evaporation and condensation interfaces

23

Heat transport capability : 1G- Static and Rotating with large heat pipe diameter

EHP AG200 MAXIMAL Heat transport capabilityComparison between Predicted 0G and 1G static and Rotating Heat transport capability of a 2m long AG200

Rotating results 652 W at 20°CStatic results 674 W at 40°C TOP/TOP

Static results 632 W at 40°C side/side

24

Heat transfer coefficients : 1G- Static and Rotating Large impact with large heat pipe diameter

EHP AG200, 20 mm diameter

1G Static 1G Static 1G Static 1G Static 1G Rotating 1G

Rotating

30% Qmax200W

30% Qmax200 W

30% Qmax200 W

30% Qmax200 W

30%Qmax 200 W

88%Qma 572W

heating

cooling

Kevap(W/(M².K))

2400 3810 5530 6000 8400 7170

Kcond(W/(M².K))

2880 8450 2970 6010 7950 5800

25

THEORY ARROUND THE EVAPORATING HEAT TRANSFER

Microregion of vaporisation According to the study performed by

Peter Stephan and validated in the frame of the Dagobert heat pipe, the

evaporator heat transfer is mainly given by the micro region heat transfer. This micro region is located at the edge

of the interface between the liquid meniscus and the groove wall.

Its length should be in the order of 1/10 mm

26

flight results recorded with the EHP AG110 “Heat Experiment” on board of the ISS

CASE 1: TWO SIDES HEATING

OG Test results and conditions:- Heating power 2 times 41W on each side- With an adiabatic temperature of = 44.2°C- The heated side temperature was = 46°C.If we assume that all grooves are primedthe following theoretical value is obtained.

OG mathematical results and conditions:- Heating power 2 times 41W on two sides- With an adiabatic temperature of = 44.2°C- If we tune the Microregion length at 0.1mm with a heat transfer coefficient of 250000W/m²K over this length,

The resulted heated side temperature correspond to the 0G at = 46°C

Temperature sensor

27

flight results recorded with the EHP AG110 “Heat Experiment” on board of the ISS con’t I

EVAPORATOR INLETCASE 2: ONE SIDE HEATING

OG Test results and conditions:- Heating power 90W on one side- With an adiabatic temperature of = 46.15°C- The heated side temperature was between

49.8 and 47.6°C (TC9 & TC11)- The opposite side was around 47°C.If we assume that all grooves are primed ,

True condition at evaporator inlet, the following mathematical value is obtained.OG mathematical results and conditions:- Heating power 90W on one side- With an adiabatic temperature of = 46.15°C- The heated side temperature is = 48.5°C- The opposite side is at = 47.5°C

The mathematical simulation match to the 0G test results

28

flight results recorded with the EHP AG110 “Heat Experiment” on board of the ISS con’t I

CASE 3: ONE SIDE HEATING

OG Test results and conditions:- Heating power 90W on one side- With an adiabatic temperature of = 46.15°C- The heated side temperature was = 52.45°C- The opposite side was between 48 et 49°C.If we assume that all grooves are primed

at the evaporator end, the following mathematicalvalue is obtained.OG mathematical results and conditions:- Heating power 90W on one side- With an adiabatic temperature of = 46.15°C- The heated side temperature is = 48.5°C- The opposite side is at = 47.5°C

The mathematical simulation doesn’t match to the 0G test results

EVAPORATOR END

29

flight results recorded with the EHP AG110 “Heat Experiment” on board of the ISS con’t II

CASE 4: ONE SIDE HEATING

OG Test results and conditions:- Heating power 90W on one side- With an adiabatic temperature of = 46.15°C- The heated side temperature was = 52.45°C- The opposite side was between 48 et 49°C.If we assume that the 4 grooves submitted to

a direct heat flux of the saddle are empty, the following theoretical value is obtained.OG mathematical results and conditions:- Heating power 90W on one side- With an adiabatic temperature of = 46.15°C- The heated side temperature is = 52.5°C- The opposite side is at = 48.7°C

The mathematical simulation match quite well with the 0G test results

EVAPORATOR END

30

0G and 1G rotating, fluid distribution in heat pipe at

power above 50% of maximum heat load

EVAPORATOR CONDENSEUR

The grooves near the saddle are directly submitted to the heat

flux.They transport the heat.

The heat load applied on the evaporator inlet and then the

liquid flow is provided mainly with the grooves near the saddle

T saddle close to Tsat

Small evaporation is produced in the

opposites grooves

The opposites grooves carry the entire heat load with a large temperature gradient between saddle

and saturation temperature

Condenser grooves are with a large liquid radius

R0 depending on the number of deprimedevaporator grooves.

This defines a P0This P0 may be lower

thanPcap max only if there are

pressure drops

The grooves near the saddle

are driedT saddle >> Tsat

The grooves near the saddle have reached

their maximum performance

Pcap max is reached in these grooves

The saddle temperature gradient

increases.

P0 = P cap initial= σl x 1/R

R

∆Pcap = not maximum

∆Pcap = maximum

∆Pcap = maxi

OR

∆Pcap = maxi

31

Ongoing development and test program“0-G Heat experiment” was an important step validating the AG110 heat pipe

performance. The relevance of the rotating heat pipe test bench was demonstrated. The ongoing program “Teplo” will validate the 0-G performance of 19 mm diameter heat pipe with Photon M2. Rotating test will be performed under 1G and during heat pipe parabolic campaign.

Even the 20 sec period is short, the parabolic campaign should demonstrate the tendancy of the evaporation and condensation Heat Transfer between various environmental conditions static or rotating 1G, 2G, 0G

32

Conclusions:

OG and 1G rotating at 18 rpm/min fits well wrt.:Maximum Heat transport capabilityEvaporation and condensation heat transfer

1G static and 0G performances fits well wrt.:Maximum Heat transport capabilityHeat transfer is dependant of tested configuration (top, bottom or side) heating, cooling.

0G and 1G rotating thermal tests has been correlated with thermal modelisation and fluid distribution in heat pipe has been confirmed.