Speaker
Akifumi Iwamoto
(National Institute for Fusion Science)
Description
A 600 W He refrigerator/liquefier with variable temperature supplies was constructed in National Institute for Fusion Science (NIFS) and its operation is started. Several cool-downs of large sized superconductors and magnets, such as a conductor of ITER TF coil and a JT-60SA superconducting coil, will be performed. The cooling performance is confirmed to meet its specifications. Two dummy heat loads were used to measure cooling capacities in the supercritical and the gas phases. Cooling capacities at 20 K and 40 K are apparently higher than the designed values. On the other hand, the cooling performance of Supercritical He (SHe) could not be estimated to be more than the requirement which is 350W cooling capacity at 4.55 K with 50 g/s at the beginning of the commissioning test. Therefore, the performance had to be proved to meet its design specifications. The gross heat load should have been evaluated from the enthalpy rise at the dummy heat load and the mass flow rate through it. It is the sum of the heater power and heat inleak at the dummy load. However the flow meter equipped in it was uncalibrated at that point. It means that the gross heat load and the mass flow rate had been uncertain. Then we applied a new method to evaluate them. The correlation between the net heater power of the dummy heat load and the resulting SHe enthalpy rise was systematically investigated under a certain mass flow rate and temperature. Finally, the calibration of the mass flow meter and the evaluation of the heat inleak were succeeded. The SHe cooling performance of 422 W at 4.42 K with 51.3 g/s has been proved. In this paper, we describe the method of the SHe cooling capacity measurement and mass flow meter calibration.
Co-authors
Akifumi Iwamoto
(National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu, Japan)
Haruhiro Higaki
(Taiyo Nippon Sanso Corporation, 6-2 kojima, Kawasaki, Kanagawa, Japan)
Kazuya Takahata
(National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu, Japan)
Kouji Nadehara
(Taiyo Nippon Sanso Corporation, 6-2 kojima, Kawasaki, Kanagawa, Japan)
Minoru Nobutoki
(Taiyo Nippon Sanso Corporation, 6-2 kojima, Kawasaki, Kanagawa, Japan)
Shinji Hamaguchi
(National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu, Japan)
Shinsaku Imagawa
(National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu, Japan)
Suguru Takada
(National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu, Japan)
Takuya Kumaki
(Taiyo Nippon Sanso Corporation, 6-2 kojima, Kawasaki, Kanagawa, Japan)
Toshiyuki Mito
(National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu, Japan)
