APS Lite ver.1 August/2006 Pre-cooling Report 8/22/2006 Tokoku 9/ 8/2006 revised ----------------------------------------------------------------------- Data log : ----------------------------------------------------------------------- Printable pdf Log ----------------------------------------------------------------------- Reports : ----------------------------------------------------------------------- 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. ----------------------------------------------------------------------- New Suggestion : ----------------------------------------------------------------------- Printable pdf Schematic