APS Lite ver.1    August/2006 Pre-cooling Report
8/22/2006 Tokoku
9/ 8/2006 revised

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Data log :
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Printable pdf  Log


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Reports :
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by Konishi, Yoshikawa, Omata, Gorman, McGrath

( 1 ) Heat from NC1-valve might waste LN2. 
( 2 ) LN2 cannot be made effective use to the last drop with Automatic-LN2-Supply-Switch.

      Omata :
      It was not simple to change a switching threashold.
      Max flow rate was also changed and chattering was occured.

      Bill :
      I observed that when the Ln2 tank switcher changed tanks 
      the difference in tank pressure required a change in control 
      valve setting.  I understand this situation because more 
      pressure will force more Ln2 through an orifice.  This does 
      cause a problem with the computer program because it will 
      have to readjust the control valve opening in response to 
      different tank pressure.

( 3 ) Excessive amount of LN2 was sometimes used.
      Things sometimes don't go the way we want with remote control.
( 4 ) Due to the reasons (1)(2)(3), double amount of LN2 were required.
( 5 ) Pumping-mode was used for 2 times manually and 1 time remortely.    
( 6 ) Power control with APC will improve...
( 7 ) The system was shutdown once due to lack of compressed-air pressure.
      (This situation must be considered as one of protection features.
      It is required to check air pressure.) 
( 8 ) The control valve may have a an opening that is too big for our application.
      I noticed that we operate within a small Ma range close to the opening point.
      If we use a control valve with a smaller orifice we may be able to use the 
      full range of operation from closed to full opening.
( 9 ) Flow meter was frozen. 


Memo:
* How about 4-tank switching?
* Next MOIRCS pre-cooling early in October.

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New Suggestion : 
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