Unexpected shutdown of vector fridge on 26 09 2012


Magnet temperatures as I found them. Magnets are hot!


Fridge temperatures as I found them. Fridge is hot


IGH front panel as I found it. All valves are shut. Mixture is behind He3 pump and in He4 dump?!


IGH panel again. Notice P3=243! . Most likely mixture.


Pressure gauges as I found them. Probe>1500 mbar and IVC no Ident -> IVC is vented !? Gas in the OVC due to warming of the fridge. Still>1500. There is mixture in the fridge.


IGH front panel after recovery. After recovery pressures don't match previous values + He3 and He4 are mixed in the dumps. Fridge Crash Sept2012 Pressure Logs MG2-MG5.
See VectorFieldFridgeMixturePressureLog for details of the fridge dump pressures, but usually they are 990mB & 1153 mB, and we are now getting 985 & 919 mB.

So there is some mixture missing -- maybe this is in the IVC (-- AlexHamilton - 27 Sep 2012) ?

Switched off both compressors.

Waiting to warm up.

Oleh wrote that he pumped the IVC into the dumps and now the dumps pressures make sense: P6=1160 and P7=989. This is basically the same as the historical values, which says that the extra gas in the IVC may well have been mixture - but how on earth did it get there?

He Leak Detection

Hooked up Leak detector to Aux Port-1, to leak check the still lines and both condensing lines.

*done whilst waiting for fridge to warm up (Magnet temperatures ~ 242K).



*Note: Here we're used the leak detector's rotary pump as a substitute for pump S4.


Result of leak checking:
IVC is holding pressure so no leakage between IVC and fridge lines (still and both condensing lines).

Perhaps it is due to a blockage.



Cleaning Mixture via Fridge Attempt

The following attempts at cycling the mixture was repeated a couple of times, and the same result was obtained every time - inidicating a blockage in the condenser lines.


Pressure Tests (5/8/12)

The following tests were conducted as per Giorgio's suggestion.


Fridge Logs of the Event

Plots of the fridge pressures & temperatures are provided below.

Crash occurred between 8:31am to 8:34am:

- Sudden heat load applied to all Plates of the fridge.

- Flow rate dropped from 177 to 0.

- Mixture was auto dumped in to P6 (He4 dumps rose from 18mbar to >500mbar)

- Mixture also auto dumped into IVC (P3 rose from ~0bar to 250mbar, MG2 and MG4 rose >1500mbar)




Magnet temperatures also increase.

Compressor Logs during that time period show no change - ie power was still on at that time and the compressors were in normal operation:

C:\Liquefier Logs\CompressorState 2012_09_24 1549.txt
Timestamp Low side PSI High side PSIIn water temp C
Out water temp CHe gas temp C
Oil temp C
Motor Amps
Diode temp K
08:31:18 082.7 264.5 070.5 087.8 134.6 081.7 15.0 NaN
08:36:26 090.0 273.9 070.9 088.5 135.0 082.4 15.0 NaN

C:\Liquefier Logs\CompressorState 2012_09_24 1551.txt

Timestamp Low side PSI High side PSIIn water temp C
Out water temp CHe gas temp C
Oil temp C
Motor Amps
Diode temp K
08:03:24083.2 268.3073.0 090.0 133.0 085.3 15.0 NaN
08:08:33082.7 268.4073.2 090.0 133.0 085.3 15.0 NaN

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Topic attachments
I Attachment Action Size Date Who Comment
26-09-2012_10-59am_MagTemp.PNGPNG 26-09-2012_10-59am_MagTemp.PNG manage 209 K 26 Sep 2012 - 08:15 LaReineYeoh fridge crash sept2012 magnet temps
Blocked_condenser_lines.docdoc Blocked_condenser_lines.doc manage 22 K 04 Oct 2012 - 07:23 LaReineYeoh Vector fridge shut down 26/9/2012 - blocked condenser lines
CH6_TMC.PNGPNG CH6_TMC.PNG manage 129 K 26 Sep 2012 - 07:16 LaReineYeoh Fridge Crash Sept2012 Tmc
IMG_20120926_095100.jpgjpg IMG_20120926_095100.jpg manage 202 K 26 Sep 2012 - 03:31 OlehKlochan  
IMG_20120926_095111.jpgjpg IMG_20120926_095111.jpg manage 157 K 26 Sep 2012 - 03:31 OlehKlochan  
IMG_20120926_095125.jpgjpg IMG_20120926_095125.jpg manage 142 K 26 Sep 2012 - 03:31 OlehKlochan  
IMG_20120926_095137.jpgjpg IMG_20120926_095137.jpg manage 163 K 26 Sep 2012 - 03:31 OlehKlochan  
IMG_20120926_095144.jpgjpg IMG_20120926_095144.jpg manage 94 K 26 Sep 2012 - 03:31 OlehKlochan  
IMG_20120926_100006.jpgjpg IMG_20120926_100006.jpg manage 143 K 26 Sep 2012 - 03:31 OlehKlochan  
IMG_20120926_101208.jpgjpg IMG_20120926_101208.jpg manage 161 K 26 Sep 2012 - 03:32 OlehKlochan  
IMG_20120926_101219.jpgjpg IMG_20120926_101219.jpg manage 171 K 26 Sep 2012 - 03:32 OlehKlochan  
Pressure_Logs_MG2-MG5.PNGPNG Pressure_Logs_MG2-MG5.PNG manage 22 K 26 Sep 2012 - 07:15 LaReineYeoh Fridge Crash Sept2012 Pressure Logs MG2-MG5
Pressure_Logs_P3-P7.pngpng Pressure_Logs_P3-P7.png manage 21 K 26 Sep 2012 - 07:16 LaReineYeoh Fridge Crash Sept2012 Pressure Logs P3-P5
VectorFridgeShutDown260912_leak_check_IMAG1040.jpgjpg VectorFridgeShutDown260912_leak_check_IMAG1040.jpg manage 895 K 02 Oct 2012 - 06:54 LaReineYeoh Pressures IVC, Still
VectorFridgeShutDown260912_leak_check_IMAG1043.jpgjpg VectorFridgeShutDown260912_leak_check_IMAG1043.jpg manage 739 K 02 Oct 2012 - 06:54 LaReineYeoh Gas handling cabinet valves
VectorFridgeShutDown260912_leak_check_IMAG1044.jpgjpg VectorFridgeShutDown260912_leak_check_IMAG1044.jpg manage 1 MB 02 Oct 2012 - 06:55 LaReineYeoh He leak detector rate
VectorFridgeShutDown260912_leak_check_IMAG1045.jpgjpg VectorFridgeShutDown260912_leak_check_IMAG1045.jpg manage 1 MB 02 Oct 2012 - 08:20 LaReineYeoh Pressures after leak checking
VectorFridgeShutDown260912_leak_check_IMAG1046.jpgjpg VectorFridgeShutDown260912_leak_check_IMAG1046.jpg manage 1 MB 02 Oct 2012 - 08:20 LaReineYeoh leak detector after leak checking
pressuretests.pngpng pressuretests.png manage 149 K 05 Oct 2012 - 03:56 LaReineYeoh Vector fridge pressure tests 5/8/12
pressuretests2.pngpng pressuretests2.png manage 183 K 05 Oct 2012 - 06:10 LaReineYeoh 5/8/12 vector fridge pressure tests
Topic revision: r10 - 09 Sep 2014, RoyLi
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