Abstract
A cryopump system for JT-60 neutral beam injector (NBI) is composed of 14 cryopumps with the largest total pumping speed of 20000 m{sup 3}/s in the world, which are cooled by liquid helium through a long-distance liquid helium transferline of about 500 m from a helium refrigerator with the largest capacity of 3000 W at 3.6 K in Japan. An automatic control method of the cryopump system has been developed and tested. Features of the automatic control method are as follows. 1) Suppression control of the thermal imbalance in cooling-down of the 14 cryopumps. 2) Stable cooling control of the cryopump due to liquid helium supply to six cryopanels by natural circulation in steady-state mode. 3) Stable liquid helium supply control for the cryopumps from the liquid helium dewar in all operation modes of the cryopumps, considering the helium quantities held in respective components of the closed helium loop. 4) Stable control of the helium refrigerator for the fluctuation in thermal load from the cryopumps and the change of operation mode of the cryopumps. In the automatic operation of the cryopump system by the newly developed control method, the cryopump system including the refrigerator was stably operated for all operation
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Shibanuma, Kiyoshi;
Akino, Noboru;
Dairaku, Masayuki;
Ohuchi, Yutaka;
Shibata, Takemasa
[1]
- Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment
Citation Formats
Shibanuma, Kiyoshi, Akino, Noboru, Dairaku, Masayuki, Ohuchi, Yutaka, and Shibata, Takemasa.
Development of automatic control method for cryopump system for JT-60 neutral beam injector.
Japan: N. p.,
1991.
Web.
Shibanuma, Kiyoshi, Akino, Noboru, Dairaku, Masayuki, Ohuchi, Yutaka, & Shibata, Takemasa.
Development of automatic control method for cryopump system for JT-60 neutral beam injector.
Japan.
Shibanuma, Kiyoshi, Akino, Noboru, Dairaku, Masayuki, Ohuchi, Yutaka, and Shibata, Takemasa.
1991.
"Development of automatic control method for cryopump system for JT-60 neutral beam injector."
Japan.
@misc{etde_10110905,
title = {Development of automatic control method for cryopump system for JT-60 neutral beam injector}
author = {Shibanuma, Kiyoshi, Akino, Noboru, Dairaku, Masayuki, Ohuchi, Yutaka, and Shibata, Takemasa}
abstractNote = {A cryopump system for JT-60 neutral beam injector (NBI) is composed of 14 cryopumps with the largest total pumping speed of 20000 m{sup 3}/s in the world, which are cooled by liquid helium through a long-distance liquid helium transferline of about 500 m from a helium refrigerator with the largest capacity of 3000 W at 3.6 K in Japan. An automatic control method of the cryopump system has been developed and tested. Features of the automatic control method are as follows. 1) Suppression control of the thermal imbalance in cooling-down of the 14 cryopumps. 2) Stable cooling control of the cryopump due to liquid helium supply to six cryopanels by natural circulation in steady-state mode. 3) Stable liquid helium supply control for the cryopumps from the liquid helium dewar in all operation modes of the cryopumps, considering the helium quantities held in respective components of the closed helium loop. 4) Stable control of the helium refrigerator for the fluctuation in thermal load from the cryopumps and the change of operation mode of the cryopumps. In the automatic operation of the cryopump system by the newly developed control method, the cryopump system including the refrigerator was stably operated for all operation modes of the cryopumps, so that the cool-down of 14 cryopumps was completed in 16 hours from the start of cool-down of the system and the cryopumps was stably cooled by natural circulation cooling in steady-state mode. (author).}
place = {Japan}
year = {1991}
month = {Oct}
}
title = {Development of automatic control method for cryopump system for JT-60 neutral beam injector}
author = {Shibanuma, Kiyoshi, Akino, Noboru, Dairaku, Masayuki, Ohuchi, Yutaka, and Shibata, Takemasa}
abstractNote = {A cryopump system for JT-60 neutral beam injector (NBI) is composed of 14 cryopumps with the largest total pumping speed of 20000 m{sup 3}/s in the world, which are cooled by liquid helium through a long-distance liquid helium transferline of about 500 m from a helium refrigerator with the largest capacity of 3000 W at 3.6 K in Japan. An automatic control method of the cryopump system has been developed and tested. Features of the automatic control method are as follows. 1) Suppression control of the thermal imbalance in cooling-down of the 14 cryopumps. 2) Stable cooling control of the cryopump due to liquid helium supply to six cryopanels by natural circulation in steady-state mode. 3) Stable liquid helium supply control for the cryopumps from the liquid helium dewar in all operation modes of the cryopumps, considering the helium quantities held in respective components of the closed helium loop. 4) Stable control of the helium refrigerator for the fluctuation in thermal load from the cryopumps and the change of operation mode of the cryopumps. In the automatic operation of the cryopump system by the newly developed control method, the cryopump system including the refrigerator was stably operated for all operation modes of the cryopumps, so that the cool-down of 14 cryopumps was completed in 16 hours from the start of cool-down of the system and the cryopumps was stably cooled by natural circulation cooling in steady-state mode. (author).}
place = {Japan}
year = {1991}
month = {Oct}
}