PURPOSE: To determine the invaded heat of a long or shape-complicated transfer pipe with good accuracy, by converting an extremely low temp. liquified cooling medium from a supply source to a gas-liquid separated two-phase stream and providing a dewer for supplying said two-phase stream to the transfer pipe.
CONSTITUTION: Liquid nitrogen (LN2) supplied to a feed-out dewer 51 from a tank 10 is converted to a gas-liquid separated two-phase stream which is, in turn, supplied to a transfer pipe 22a through a temporarily constructed pipe 20b. Next, LN2 supplied to the pipe 22a through the pipe 20b absorbs invaded heat which flowed through the pipe 22a and, thereafter, only gaseous nitrogen (GN2) is supplied to a branched pipe 22b and GN2 flowed through the pipe 22b is discharged to the open air through a temporarily constructed pipe 20c, a dewer 55 and a heater 12a. At this time, total invaded heat can be calculated from enthalpy of LN2 calculated from pressure measured by a pressure gauge 31, enthalpy calculated from the temp. measured by a thermometer 32b and the flow amount measured by a flow meter 33a and invaded heat measured beforehand is subtracted from the total invaded heat to calculate the invaded heat of the pipes 22a, 22b. Therefore, the invaded heat of a long or shape-complicated transfer pipe can be determined with good accuracy.
MATSUMOTO KOUZOU
HOSOMI NOBUYUKI
TAKEI NOBUYUKI
TAKADA TADASHI
HAYASHI KENJI
HITACHI LTD