Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen

Masataka Iwakuma, K. Adachi, K. Yun, K. Yoshida, S. Sato, Y. Suzuki, T. Umeno, M. Konno, H. Hayashi, T. Eguchi, T. Izumi, Y. Shiohara

研究成果: ジャーナルへの寄稿Conference article

抄録

We developed a turbo-Brayton refrigerator with Ne gas as a working fluid for a 3θ- 66/6.9kV-2MVA superconducting transformer with coated conductors which was bath-cooled with subcooled LN 2 . The two-stage compressor and expansion turbine had non-contact magnetic bearings for a long maintenance interval. In the future, we intend to directly install a heat exchanger into the Glass-Fiber-Reinforced-Plastics cryostat of a transformer and make a heat exchange between the working fluid gas and subcooled LN 2 . In this paper we investigate the behaviour of subcooled LN 2 in a test cryostat, in which heater coils were arranged side by side with a flat plate finned-tube heat exchanger. Here a He turbo-Brayton refrigerator was used as a substitute for a Ne turbo-Brayton one. The pressure at the surface of LN 2 in the cryostat was one atmosphere. Just under the LN2 surface, a stationary layer of LN 2 was created over the depth of 20 cm and temperature dropped from 77 K to 65 K with depth while, in the lower level than that, a natural convection flow of LN 2 was formed and temperature was almost uniform over 1 m depth. The boundary plane between the stationary layer and the natural convection region was visible.

元の言語英語
記事番号012026
ジャーナルIOP Conference Series: Materials Science and Engineering
101
発行部数1
DOI
出版物ステータス出版済み - 12 18 2015
イベント2015 Joint Cryogenic Engineering and International Cryogenic Materials Conferences, CEC/ICMC 2015 - Tucson, 米国
継続期間: 6 28 20157 2 2015

Fingerprint

Cryostats
Refrigerators
Liquid nitrogen
Cooling systems
Natural convection
Gases
Glass fiber reinforced plastics
Magnetic bearings
Fluids
Heat exchangers
Compressors
Turbines
Temperature

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)

これを引用

Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen. / Iwakuma, Masataka; Adachi, K.; Yun, K.; Yoshida, K.; Sato, S.; Suzuki, Y.; Umeno, T.; Konno, M.; Hayashi, H.; Eguchi, T.; Izumi, T.; Shiohara, Y.

:: IOP Conference Series: Materials Science and Engineering, 巻 101, 番号 1, 012026, 18.12.2015.

研究成果: ジャーナルへの寄稿Conference article

Iwakuma, Masataka ; Adachi, K. ; Yun, K. ; Yoshida, K. ; Sato, S. ; Suzuki, Y. ; Umeno, T. ; Konno, M. ; Hayashi, H. ; Eguchi, T. ; Izumi, T. ; Shiohara, Y. / Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen. :: IOP Conference Series: Materials Science and Engineering. 2015 ; 巻 101, 番号 1.
@article{3c8d902f8beb415c8e71d850ed95bd61,
title = "Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen",
abstract = "We developed a turbo-Brayton refrigerator with Ne gas as a working fluid for a 3θ- 66/6.9kV-2MVA superconducting transformer with coated conductors which was bath-cooled with subcooled LN 2 . The two-stage compressor and expansion turbine had non-contact magnetic bearings for a long maintenance interval. In the future, we intend to directly install a heat exchanger into the Glass-Fiber-Reinforced-Plastics cryostat of a transformer and make a heat exchange between the working fluid gas and subcooled LN 2 . In this paper we investigate the behaviour of subcooled LN 2 in a test cryostat, in which heater coils were arranged side by side with a flat plate finned-tube heat exchanger. Here a He turbo-Brayton refrigerator was used as a substitute for a Ne turbo-Brayton one. The pressure at the surface of LN 2 in the cryostat was one atmosphere. Just under the LN2 surface, a stationary layer of LN 2 was created over the depth of 20 cm and temperature dropped from 77 K to 65 K with depth while, in the lower level than that, a natural convection flow of LN 2 was formed and temperature was almost uniform over 1 m depth. The boundary plane between the stationary layer and the natural convection region was visible.",
author = "Masataka Iwakuma and K. Adachi and K. Yun and K. Yoshida and S. Sato and Y. Suzuki and T. Umeno and M. Konno and H. Hayashi and T. Eguchi and T. Izumi and Y. Shiohara",
year = "2015",
month = "12",
day = "18",
doi = "10.1088/1757-899X/101/1/012026",
language = "English",
volume = "101",
journal = "IOP Conference Series: Materials Science and Engineering",
issn = "1757-8981",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Development of cooling system for 66/6.9kV-20MVA REBCO superconducting transformers with Ne turbo-Brayton refrigerator and subcooled liquid nitrogen

AU - Iwakuma, Masataka

AU - Adachi, K.

AU - Yun, K.

AU - Yoshida, K.

AU - Sato, S.

AU - Suzuki, Y.

AU - Umeno, T.

AU - Konno, M.

AU - Hayashi, H.

AU - Eguchi, T.

AU - Izumi, T.

AU - Shiohara, Y.

PY - 2015/12/18

Y1 - 2015/12/18

N2 - We developed a turbo-Brayton refrigerator with Ne gas as a working fluid for a 3θ- 66/6.9kV-2MVA superconducting transformer with coated conductors which was bath-cooled with subcooled LN 2 . The two-stage compressor and expansion turbine had non-contact magnetic bearings for a long maintenance interval. In the future, we intend to directly install a heat exchanger into the Glass-Fiber-Reinforced-Plastics cryostat of a transformer and make a heat exchange between the working fluid gas and subcooled LN 2 . In this paper we investigate the behaviour of subcooled LN 2 in a test cryostat, in which heater coils were arranged side by side with a flat plate finned-tube heat exchanger. Here a He turbo-Brayton refrigerator was used as a substitute for a Ne turbo-Brayton one. The pressure at the surface of LN 2 in the cryostat was one atmosphere. Just under the LN2 surface, a stationary layer of LN 2 was created over the depth of 20 cm and temperature dropped from 77 K to 65 K with depth while, in the lower level than that, a natural convection flow of LN 2 was formed and temperature was almost uniform over 1 m depth. The boundary plane between the stationary layer and the natural convection region was visible.

AB - We developed a turbo-Brayton refrigerator with Ne gas as a working fluid for a 3θ- 66/6.9kV-2MVA superconducting transformer with coated conductors which was bath-cooled with subcooled LN 2 . The two-stage compressor and expansion turbine had non-contact magnetic bearings for a long maintenance interval. In the future, we intend to directly install a heat exchanger into the Glass-Fiber-Reinforced-Plastics cryostat of a transformer and make a heat exchange between the working fluid gas and subcooled LN 2 . In this paper we investigate the behaviour of subcooled LN 2 in a test cryostat, in which heater coils were arranged side by side with a flat plate finned-tube heat exchanger. Here a He turbo-Brayton refrigerator was used as a substitute for a Ne turbo-Brayton one. The pressure at the surface of LN 2 in the cryostat was one atmosphere. Just under the LN2 surface, a stationary layer of LN 2 was created over the depth of 20 cm and temperature dropped from 77 K to 65 K with depth while, in the lower level than that, a natural convection flow of LN 2 was formed and temperature was almost uniform over 1 m depth. The boundary plane between the stationary layer and the natural convection region was visible.

UR - http://www.scopus.com/inward/record.url?scp=84959889775&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84959889775&partnerID=8YFLogxK

U2 - 10.1088/1757-899X/101/1/012026

DO - 10.1088/1757-899X/101/1/012026

M3 - Conference article

VL - 101

JO - IOP Conference Series: Materials Science and Engineering

JF - IOP Conference Series: Materials Science and Engineering

SN - 1757-8981

IS - 1

M1 - 012026

ER -