15th Conference on Thermophysics Applications in ...15th Conference on Thermophysics Applications in...

GOES Type III Loop Heat Pipe Life Test Results

15th

Conference on Thermophysics Applications in Microgravity

The Aerospace Corporation

Los Angeles, CA

March 7, 2011

Laura Ottenstein

NASA/Goddard Space Flight Center

Greenbelt, MD

[email protected]

Phone: 301-286-4141

The GOES Type III Loop Heat Pipe (LHP) was built as a life test unit for the loop heat pipes on the

GOES N-Q series satellites. This propylene LHP was built by Dynatherm Corporation in 2000 and tested

continuously for approximately 14 months. It was then put into storage for 3 years. Following the

storage period, the LHP was tested at Swales Aerospace to verify that the loop performance hadn’t

changed. Most test results were consistent with earlier results. At the conclusion of testing at Swales, the

LHP was transferred to NASA/GSFC for continued periodic testing. The LHP has been set up for testing

in the Thermal Lab at GSFC since 2006. A group of tests consisting of start-ups, power cycles, and a heat

transport limit test have been performed every six to nine months since March 2006. Tests results have

shown no change in the loop performance over the five years of testing. This presentation will discuss the

test hardware, test set-up, and tests performed. Test results to be presented include sample plots from

individual tests, along with conductance measurements for all tests performed.

mailto:[email protected]

GOES Type III Loop Heat Pipe Life Test Results

15th Conference on Thermophysics Applications in Microgravity7 March 2011

Laura OttensteinNASA/Goddard Space Flight Center

Greenbelt, MD [email protected]

Phone: 301-286-4141

mailto:[email protected]�

Outline

• Background• Test Article• Test Set-up• Tests Performed• Results• Conclusions

7 March 2011 15th Conference on Thermophysics Applications in Microgravity 2

BACKGROUND


Background

• GOES Type III Loop Heat Pipe (LHP) was built as a Life Test Unit for the LHPs on the GOES N-Q series satellites

• Built by Dynatherm Corporation in 2000 for Boeing and later transferred to Swales Aerospace

• Operated continuously at Dynatherm for approximately 14 months, then put into storage at Boeing until 2004

• Tested again at Swales in 2004– Unexpected performance during cold sink identification test led to additional tests

and additional unexpected performance– At conclusion of testing it was determined that performance anomaly was most

likely due to test set-up or gravity effects and not likely to occur on orbit• LHP was transferred to GSFC in 2006 for continued periodic testing (in

ambient)• LHP has been tested every six to nine months from March 2006 through

January 2011


TEST ARTICLE AND TEST SET-UP


LHP Description

• LHP contains a single 2.54 cm (1”) diameter evaporator and a single condenser

• Condenser has flanges in cooling locations, but no mounting holes

• Flexible sections in liquid and vapor lines, although not significantly flexed in current test set-up

• Charged with propylene


Loop Schematic with Thermocouple Locations


COMPENSATION ,. HEATER BLOCK 13 33 . SINK

LIQU ID LINE

34 e AMB IENT

11

15

VAPOR 16 GOES Type III LHP LINE 10 8765432

Test Set-Up

• Loop heat pipe held vertically by a support frame• Six parallel cooling lines plumbed to chiller (reverse return). Square tubing

is connected with thermal grease and tie wraps to condenser flanges• Approximately 36 Type T thermocouples installed on LHP using aluminum

tape• Aluminum heater block (825 grams) and starter heater saddle mounted to

evaporator– Grafoil used between heater block and evaporator mounting flange– Cartridge heater capable of up to 500 W installed in heater block– Cartridge heater capable of up to 50 W installed in starter heater saddle

• Thermocouple data collected using a Agilent Data Acquisition Unit and displayed on PC using LabView

• Heaters controlled manually using variacs• Power readings displayed on Valhalla Scientific Digital Power Analyzers

and recorded manually – over-temperature controllers in heater circuits for safety


LHP in Test Frame


Compensation Chamber

Evaporator and evaporator thermal mass

Condenser lines attached to chiller coolant lines

Vapor Line

Flexible sections in transport lines

Evaporator/Compensation Chamber


Compensation Chamber

Evaporator

Evaporator thermal mass

Starter heater bracket

Test Set-Up - Insulation

• Condenser/chiller tube assemblies are individually wrapped with aluminum foil and then wrapped with an overlapping layer of Spiral-On II thermal insulating tape

• Chiller coolant lines and transport lines individually insulated with polymer insulation foam

• Evaporator and Compensation Chamber assemblies insulated with Nomex; Nomex wrapped with Spiral-On II thermal insulating tape to limit condensation on Nomex


LHP with Insulation


TESTS PERFORMED


Test Rounds

• Each test round (every 6 – 9 months) consisted of approximately 5 days of testing:– Start-up/Heat Transport Limit Test (one test)– Start-up/Power Cycle with condenser preconditioning (one

test)

– Start-up/Power Cycle without condenser preconditioning (repeated for three tests total)

• Test order was not consistent between rounds• Loop was left idle (off), but undisturbed between

test rounds


Start-up/Power Cycle with condenser pre-conditioning

• Chiller turned on and set to -40 °C and condenser temperatures allowed to stabilize

• 10 W to starter heater, 50 W to thermal mass heater• Thirty minutes after loop start, thermal mass power

increased to 150 W and allowed to stabilize (10 W left on starter heater)

• Thermal mass power decreased to 50 W and allowed to stabilize (10 W left on starter heater)

• All power off, chiller off


Start-up/Power Cycle without condenser pre-conditioning

• Chiller turned on and set to -40 °C, 10 W to starter heater, 50 W to thermal mass heater, all simultaneously

• Thirty minutes after loop start, thermal mass power increased to 150 W and allowed to stabilize (10 W left on starter heater)

• Thermal mass power decreased to 50 W and allowed to stabilize (10 W left on starter heater)



Start-up/Transport Limit Test

• Chiller turned on and set to -40 °C and condenser temperatures allowed to stabilize

• 10 W to starter heater, 50 W to thermal mass heater• Thirty minutes after loop start, thermal mass power increased

to 100 W and allowed to stabilize (10 W left on starter heater throughout entire test)

• Thermal mass power increased in 50 W steps until 200 W reached, then in 25 W steps. System allowed to stabilize after each power change

• When loop shows clear signs of dryout, power decreased to 50 W and allowed to stabilize



TEST RESULTS


Results: Start-Up Tests

• In all tests, LHP started within five minutes of power application

• CC temperature generally constant before start-up– In a few tests, the CC temperature increased when power

was applied to the evaporator; these tests had the longer start-up times

• Evaporator start-up superheat ranged from 3.5 °C to 7.8 °C, with an average value of 5.7


Typical Start-Up


!,!.

~ l!! 0 c. E 0 I-

GOES Type III LHP Test, 6/9/2009 Start-Up, no condenser preconditioning

30.0 ~------------------------------------------------------------------------------, 300

25.0 250

--- - -_.-

20.0 200

;[ 15.0 150 G:;

10.0 100

5 .0 t------------------------------------r~r_------',""""~---"""':_----__+ 50

0.0 L----,----~----~--_,----~----~--~t:::~::::::::::~~~::~~::::~~~::::j 0 10:30 10:31 10:32 10:33 10:34 10:35 10:36 10:37 10:38 10:39 10:40 10:41 10:42 10:43 10:44 10:45

Time (HH:MM)

--- T Evap Ave --- T eG Ave --- Vaporline (16) ---Vapor Line (17) --- Cond1 (18)

--- Cond 2 (19) --- Cond 3 (20) --- Cond4 (2 1) --- Cond 7 (24) --- Cond Outlet (29)

--- Liq in to CC (32) --- Coolant Inlet (37) ---Starter Heater Power--- Evap Power

~ 0 c.

Start-up with CC Temperature Increase


!,!.

~ l!! • c. E • I-

GOES Type III LHP Test - 4/3/2006 Start-Up, no condenser preconditioning

30 ~------------------------------------------------------------------------------, 300

250

20 200

[ 150 a;

10

\ 100

50

o ~~--~--J===~~===;~~~~~~=;==~==~~==~==~ o 8:45 8:46 8:47 8:48 8:49 8:50 8:51 8:52 8:53 8:54 8:55 8:56 8:57 8:58 8:59 9:00

Time (HH:MIN)

--T Evap Ave --TeGAve --Vapor Lin e (16) --Vapor Lin e (17) --Cond1 (18)

--Cond 2 (19) --Cond 3 (20) --Cond4 (2 1) --Cond7 (24) -- Cond Outlet (29)

-- Liq In to CC (32) --Coolant Inlet (37) --Starter Heater Power --Evap Power

• 0 ..

Results: Power Cycles with condenser preconditioning

• All tests completed successfully• Similar conductances in all tests (shown later in

presentation)

• Frequent temperature “blip” in CC inlet temperature believed to be caused by gravity effects as condenser opens


Start-Up/Power Cyclewith condenser preconditioning


30.0

20 .0

10.0

0.0

~ !! -1 0.0 • c. E • I- -20.0

-30.0

-40.0

I \

~ ~

-50.0

8:00 9:00

--T EvapAve

--Cond2 (19)

-- Liq in to CC (32)

GOES Type III LHP Test - 6/12/09 Start-Up/Power Cycle, w ith condenser preconditioning

1\'

~ \\

[~, ~ ~

r( r-= I

10:00 11:00 12:00 Time (HH:MM)

--T eGAve --Vaporlin e (16)

--Cond3 (20) --Cond 4 (21)

(~ p< /'

13:00

Vapor Lin e (17)

--Cond7 (24)

--Coolant Inlet (37) --Starter Heater Power --Evap Power

I

I 14:00

--Cond 1 (18)

--Cond Outlet (29)

400

350

300

250

;[ 200 G:;

150

100

50

o 15:00

~ c.

Results: Power Cycles without condenser preconditioning

• All tests completed successfully• Similar conductances in all tests (shown later in

presentation)

• Similar results to tests with condenser preconditioning– Powerful chiller means that condenser cools quickly when

chiller is started


Start-up/Power Cyclewithout condenser preconditioning


0

50

100

150

200

250

300

350

400

-50

-40

-30

-20

-10

0

10

20

30

40

11:00 12:00 13:00 14:00 15:00 16:00

Pow

er (W

)

Tem

pera

ture

(°C)

Time (HH:MM)

GOES Type III LHP Test - 12/29/2010Start-up, without condenser preconditioning

T Evap Ave T CC Ave Vapor line (16) Vapor Line (17) Cond 1 (18)

Cond 2 (19) Cond 3 (20) Cond 4 (21) Cond 7 (24) Cond Outlet (29)

Liq in to CC (32) Coolant Inlet (37) Starter Heater Power Evap Power

Results: Heat Transport Limit Test

• Maximum power during test ranged from 310 W to 360 W– Dryout difficult to discern during testing, mainly seen as

increasing temperature difference between evaporator and CC

– Conductance calculations done after the tests indicate that loop performance always starts to degrade above 285 W

• Loop always recovered at turn-down power of 50 W• No significant change in performance over time


Start-up/Heat Transport Limit Test


30.0

20.0

10.0

0.0

E ~ , ~ ·10.0 . ~

E . ~

·20.0

·30.0

·40.0

·50.0

'-- ~

Goes Type III LHP Test - 6/19/2009 Start-Up/Transport Limit Test

~ ~ ~ ?-;;

./ ~~ J =4'" If I -:.-----' I\l " -...::::::::::: --::: V

I

1\

~ r- IT l --I r k ~"r- I~

'----'-- -

9:00 10:00 11 :00 12 :00 13 :00 14:00 15 :00 16:00 17:00

Time (HH:MM)

- TEvapAve - TCCAve - Vapor line (16) - Vapor line (17) - Cond1(18)

- Cond2(19) - Cond3(20) - Cond4(21) - Cond7(24) - Cond Outlet (29)

- liqintoCC(32) Coolant Inlet (37) - Starter Heater Power - Evap Power

400

350

300

250

200

150

100

50

o 18:00

! • • 0 ~

Conductance CalculationsThree conductance values were calculated for each test Total conductance is defined as:

Q aCT = Tevap,ave – Tcond,ave

where Q is the total power into the evaporator, Tevap, ave is the average evaporator temperature (TCs 2-9), and Tcond, ave is the average of TCs 18 and 19.

Evaporator conductance is defined as:Q a

Cevap = Tevap,ave – TCC,ave

where TCC,ave is the average compensation chamber temperature (TCs 10-14).

Condenser conductance is defined as:

Q a

Ccond = TCC,ave – Tcond,ave


Heat Transport Limit TestTotal Conductance

0

10

20

30

40

50

60

70

80

90

0 50 100 150 200 250 300 350 400

Cond

ctan

ce (

W/°

C)

Power (W)

GOES Type III LHPTotal Conductance

3/27/2006 12/15/2006 7/6/2007 3/27/2008 11/13/2008 12/4/2008 6/19/2009 3/16/2010 1/4/2011


Heat Transport Limit TestEvaporator Conductance

0

50

100

150

200

250

0 50 100 150 200 250 300 350 400

Cond

ucta

nce

(W/°

C)

Total Power (W)

GOES Type III LHPEvaporator Conductance

3/27/2006 12/15/2006 7/6/2007 3/27/2008 11/13/2008 12/4/2008 6/19/2009 3/16/2010 1/4/2011


Heat Transport Limit TestCondenser Conductance

0

20

40

60

80

100

120

140

160

180

200

0 50 100 150 200 250 300 350 400

Cond

ucta

nce

(W/°

C)

Power (W)

GOES Type III LHPCondenser Conductance

3/27/2006 12/15/2006 7/6/2007 3/27/2008 11/13/2008 12/4/2008 6/19/2009 3/16/2010 1/4/2011


Conductances at 160 W (for all tests performed, in chronological order)

0

50

100

150

200

250

0 5 10 15 20 25 30 35 40

Cond

ucta

nce

(W/C

)

Test Number

GOES Type III LHP Conductance At 160 W

Total Cond Evap

March - May 2006 March - April 2008

July 2007 Nov - Dec 2008December 2006 June 2009 March 2010 Sep 2010 -Jan 2011


Conclusions

• No test anomaly seen throughout test program• Partial dryouts during heat transport limit tests only• No significant change in operation over time span

tested – Due to changes in test configuration, instrumentation, and

test parameters, data cannot be directly compared to data from Dynatherm or Swales tests

• LHP test set-up remains undisturbed. Additional testing will be performed if funding can be located.


2011008008-1.pdfGOES Type III Loop Heat Pipe �Life Test ResultsOutlineBackgroundBackgroundTest Article and Test Set-upLHP DescriptionLoop Schematic �with Thermocouple LocationsTest Set-UpLHP in Test FrameEvaporator/Compensation ChamberTest Set-Up - InsulationLHP with InsulationTests PerformedTest RoundsStart-up/Power Cycle �with condenser pre-conditioningStart-up/Power Cycle �without condenser pre-conditioningStart-up/Transport Limit TestTest ResultsResults: Start-Up TestsTypical Start-UpStart-up with CC Temperature IncreaseResults: Power Cycles �with condenser preconditioningStart-Up/Power Cycle�with condenser preconditioningResults: Power Cycles �without condenser preconditioningStart-up/Power Cycle�without condenser preconditioningResults: Heat Transport Limit TestStart-up/Heat Transport Limit TestConductance CalculationsHeat Transport Limit Test�Total Conductance Heat Transport Limit Test�Evaporator ConductanceHeat Transport Limit Test�Condenser ConductanceConductances at 160 W �(for all tests performed, in chronological order)Conclusions

15th Conference on Thermophysics Applications in ...15th Conference on Thermophysics Applications in...

Documents

Transcript of 15th Conference on Thermophysics Applications in ...15th Conference on Thermophysics Applications in...