Speaker
Mr
Oleg Kovalchuk
(NIIEFA)
Description
Insulation breaks are used in cryogenic lines with gas or liquid (helium, hydrogen, nitrogen, etc.) at a temperature range of 4.2-300 K and pressure up to 30 MPa to isolate the parts of an electrophysical facility with different electrical potentials. In 2013 NIIEFA delivered 95 insulation breaks to the IO ITER, i.e. 65 spiral-type breaks and 30 uniflow-type breaks. These insulators were designed, manufactured and tested in accordance with the ITER Technical Specifications: Axial Insulating Breaks for the Qualification Phase of ITER Coils and Feeders. The insulation breaks consist of the glass-reinforced plastic cylinder equipped with channels for cryoagent and stainless steel end fittings. The operating voltage is 30 kV for the spiral-type breaks and 4 kV for the uniflow-type breaks. The main design feature of the spiral-type insulation break is the spiral channel instead of a linear one. This approach has enabled us to increase the breakdown voltage and decrease the overall dimensions of the insulation breaks. In 2013 the manufacturing technique was developed to produce the insulation breaks with the spiral and uniflow channels that made it possible to proceed to serial production. To provide the acceptance tests of the breaks the special test facility was prepared. The helium tightness test at 10-11 m3∙Pa/s under the pressure up to 30 MPa, the high voltage test up to 135 kV and different types of mechanical tests were carried out at the room and liquid nitrogen temperatures.
Author
Mr
Oleg Kovalchuk
(NIIEFA)
Co-authors
Mr
Aleksandr Safonov
(NIIEFA)
Mr
Andrey Bursikov
(NIIEFA)
Mr
Andrey Lancetov
(NIIEFA)
Mr
Andrey Mednikov
(NIIEFA)
Dr
Igor Rodin
(NIIEFA)
Ms
Natalya Smorodina
(NIIEFA)
Mr
Nikolay Voronin
(NIIEFA)
Mr
Slava Grinchenko
(NIIEFA)
Mr
Yury Klimchenko
(NIIEFA)
