Consideration of sub-cooled LN2 circulation system for HTS power equipment

Shigeru Yoshida, H. Hirai, N. Nara, T. Nagasaka, M. Hirokawa, H. Okamoto, H. Hayashi, Y. Shiohara

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Citations (Scopus)

Abstract

We consider a sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The planned circulation system consists of a sub-cool heat exchanger (subcooler) and a circulation pump. The sub-cooler will be connected to a neon turbo-Brayton cycle refrigerator with a cooling power of 2 kW at 65 K. Sub-cooled LN will be delivered into the sub-cooler by the pump and cooled within it. Sub-cooled LN is adequate fluid for cooling HTS power equipment, because its dielectric strength is high and it supports a large critical current. However, a possibility of LN solidification in the sub-cooler is a considerable issue. The refrigerator will produce cold neon gas of about 60 K, which is lower than the nitrogen freezing temperature of 63 K. Therefore, we designed two-stage heat exchangers which are based on a plate-fin type and a tube-intube type. Process simulations of those heat exchangers indicate that sub-cooled LN is not frozen in either sub-cooler. The plate-fin type sub-cooler is consequently adopted for its reliability and compactness. Furthermore, we found that a cooling system with a Brayton refrigerator has the same total cooling efficiency as a cooling system with a Stirling refrigerator.

Original languageEnglish
Title of host publicationAdvances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC
Pages1649-1656
Number of pages8
Edition57
DOIs
Publication statusPublished - Aug 8 2012
Externally publishedYes
Event2011 Joint Cryogenic Engineering and International Cryogenic Materials Conferences - Spokane, WA, United States
Duration: Jun 13 2011Jun 17 2011

Publication series

NameAIP Conference Proceedings
Number57
Volume1434
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Conference

Conference2011 Joint Cryogenic Engineering and International Cryogenic Materials Conferences
CountryUnited States
CitySpokane, WA
Period6/13/116/17/11

Fingerprint

coolers
liquid nitrogen
refrigerators
heat exchangers
cooling systems
fins
cooling
neon
Brayton cycle
pumps
void ratio
high strength
freezing
solidification
critical current
tubes
nitrogen
fluids
gases
simulation

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Yoshida, S., Hirai, H., Nara, N., Nagasaka, T., Hirokawa, M., Okamoto, H., ... Shiohara, Y. (2012). Consideration of sub-cooled LN2 circulation system for HTS power equipment. In Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC (57 ed., pp. 1649-1656). (AIP Conference Proceedings; Vol. 1434, No. 57). https://doi.org/10.1063/1.4707097

Consideration of sub-cooled LN2 circulation system for HTS power equipment. / Yoshida, Shigeru; Hirai, H.; Nara, N.; Nagasaka, T.; Hirokawa, M.; Okamoto, H.; Hayashi, H.; Shiohara, Y.

Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC. 57. ed. 2012. p. 1649-1656 (AIP Conference Proceedings; Vol. 1434, No. 57).

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Yoshida, S, Hirai, H, Nara, N, Nagasaka, T, Hirokawa, M, Okamoto, H, Hayashi, H & Shiohara, Y 2012, Consideration of sub-cooled LN2 circulation system for HTS power equipment. in Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC. 57 edn, AIP Conference Proceedings, no. 57, vol. 1434, pp. 1649-1656, 2011 Joint Cryogenic Engineering and International Cryogenic Materials Conferences, Spokane, WA, United States, 6/13/11. https://doi.org/10.1063/1.4707097
Yoshida S, Hirai H, Nara N, Nagasaka T, Hirokawa M, Okamoto H et al. Consideration of sub-cooled LN2 circulation system for HTS power equipment. In Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC. 57 ed. 2012. p. 1649-1656. (AIP Conference Proceedings; 57). https://doi.org/10.1063/1.4707097
Yoshida, Shigeru ; Hirai, H. ; Nara, N. ; Nagasaka, T. ; Hirokawa, M. ; Okamoto, H. ; Hayashi, H. ; Shiohara, Y. / Consideration of sub-cooled LN2 circulation system for HTS power equipment. Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC. 57. ed. 2012. pp. 1649-1656 (AIP Conference Proceedings; 57).
@inproceedings{049c956debf44c1d98d3a229946292ce,
title = "Consideration of sub-cooled LN2 circulation system for HTS power equipment",
abstract = "We consider a sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The planned circulation system consists of a sub-cool heat exchanger (subcooler) and a circulation pump. The sub-cooler will be connected to a neon turbo-Brayton cycle refrigerator with a cooling power of 2 kW at 65 K. Sub-cooled LN will be delivered into the sub-cooler by the pump and cooled within it. Sub-cooled LN is adequate fluid for cooling HTS power equipment, because its dielectric strength is high and it supports a large critical current. However, a possibility of LN solidification in the sub-cooler is a considerable issue. The refrigerator will produce cold neon gas of about 60 K, which is lower than the nitrogen freezing temperature of 63 K. Therefore, we designed two-stage heat exchangers which are based on a plate-fin type and a tube-intube type. Process simulations of those heat exchangers indicate that sub-cooled LN is not frozen in either sub-cooler. The plate-fin type sub-cooler is consequently adopted for its reliability and compactness. Furthermore, we found that a cooling system with a Brayton refrigerator has the same total cooling efficiency as a cooling system with a Stirling refrigerator.",
author = "Shigeru Yoshida and H. Hirai and N. Nara and T. Nagasaka and M. Hirokawa and H. Okamoto and H. Hayashi and Y. Shiohara",
year = "2012",
month = "8",
day = "8",
doi = "10.1063/1.4707097",
language = "English",
isbn = "9780735410206",
series = "AIP Conference Proceedings",
number = "57",
pages = "1649--1656",
booktitle = "Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC",
edition = "57",

}

TY - GEN

T1 - Consideration of sub-cooled LN2 circulation system for HTS power equipment

AU - Yoshida, Shigeru

AU - Hirai, H.

AU - Nara, N.

AU - Nagasaka, T.

AU - Hirokawa, M.

AU - Okamoto, H.

AU - Hayashi, H.

AU - Shiohara, Y.

PY - 2012/8/8

Y1 - 2012/8/8

N2 - We consider a sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The planned circulation system consists of a sub-cool heat exchanger (subcooler) and a circulation pump. The sub-cooler will be connected to a neon turbo-Brayton cycle refrigerator with a cooling power of 2 kW at 65 K. Sub-cooled LN will be delivered into the sub-cooler by the pump and cooled within it. Sub-cooled LN is adequate fluid for cooling HTS power equipment, because its dielectric strength is high and it supports a large critical current. However, a possibility of LN solidification in the sub-cooler is a considerable issue. The refrigerator will produce cold neon gas of about 60 K, which is lower than the nitrogen freezing temperature of 63 K. Therefore, we designed two-stage heat exchangers which are based on a plate-fin type and a tube-intube type. Process simulations of those heat exchangers indicate that sub-cooled LN is not frozen in either sub-cooler. The plate-fin type sub-cooler is consequently adopted for its reliability and compactness. Furthermore, we found that a cooling system with a Brayton refrigerator has the same total cooling efficiency as a cooling system with a Stirling refrigerator.

AB - We consider a sub-cooled liquid nitrogen (LN) circulation system for HTS power equipment. The planned circulation system consists of a sub-cool heat exchanger (subcooler) and a circulation pump. The sub-cooler will be connected to a neon turbo-Brayton cycle refrigerator with a cooling power of 2 kW at 65 K. Sub-cooled LN will be delivered into the sub-cooler by the pump and cooled within it. Sub-cooled LN is adequate fluid for cooling HTS power equipment, because its dielectric strength is high and it supports a large critical current. However, a possibility of LN solidification in the sub-cooler is a considerable issue. The refrigerator will produce cold neon gas of about 60 K, which is lower than the nitrogen freezing temperature of 63 K. Therefore, we designed two-stage heat exchangers which are based on a plate-fin type and a tube-intube type. Process simulations of those heat exchangers indicate that sub-cooled LN is not frozen in either sub-cooler. The plate-fin type sub-cooler is consequently adopted for its reliability and compactness. Furthermore, we found that a cooling system with a Brayton refrigerator has the same total cooling efficiency as a cooling system with a Stirling refrigerator.

UR - http://www.scopus.com/inward/record.url?scp=84864761590&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84864761590&partnerID=8YFLogxK

U2 - 10.1063/1.4707097

DO - 10.1063/1.4707097

M3 - Conference contribution

AN - SCOPUS:84864761590

SN - 9780735410206

T3 - AIP Conference Proceedings

SP - 1649

EP - 1656

BT - Advances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC

ER -