Abstract
A two-phase flow has characteristics of the blockage instability in which voids prevent and stop the water flow in an inverted U-tube. In cooler c{sub 32} employing inverted U-tubes, changes of heat transfer performance, abnormal mechanical vibrations and corrosions on the surfaces of cooling tubes had been observed during the operations of HENDEL (Helium Engineering Demonstration Loop). It was assumed that the causes of these abnormal events were air stagnated in inverted U-tubes when cooling water was filled before HENDEL operation. A blockage instability of two-phase flow and stability boundaries were investigated with an experimental apparatus composed of water plenums and an inverted U-tube which is parallel to a bypass channel. `Dynamic air vent` and `Vacuum air vent` methods were additionally suggested to reject the stagnated air in the inverted U-tubes. As the results of experiments, the possibility of Dynamic air vent method was verified using the experimental apparatus. And, the usefulness of Vacuum air vent method was also demonstrated through the tests employing cooler C{sub 32} of HENDEL. (author).
Takada, Shoji;
Shibata, Mitsuhiko;
Kato, Mitio;
Fujisaki, Katsuo;
Ohta, Yukimaru;
Kobayashi, Toshiaki;
Hayashi, Haruyoshi
[1]
- Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
Citation Formats
Takada, Shoji, Shibata, Mitsuhiko, Kato, Mitio, Fujisaki, Katsuo, Ohta, Yukimaru, Kobayashi, Toshiaki, and Hayashi, Haruyoshi.
Study of air vent design for inverted U-tube type heat exchanger.
Japan: N. p.,
1994.
Web.
Takada, Shoji, Shibata, Mitsuhiko, Kato, Mitio, Fujisaki, Katsuo, Ohta, Yukimaru, Kobayashi, Toshiaki, & Hayashi, Haruyoshi.
Study of air vent design for inverted U-tube type heat exchanger.
Japan.
Takada, Shoji, Shibata, Mitsuhiko, Kato, Mitio, Fujisaki, Katsuo, Ohta, Yukimaru, Kobayashi, Toshiaki, and Hayashi, Haruyoshi.
1994.
"Study of air vent design for inverted U-tube type heat exchanger."
Japan.
@misc{etde_10155987,
title = {Study of air vent design for inverted U-tube type heat exchanger}
author = {Takada, Shoji, Shibata, Mitsuhiko, Kato, Mitio, Fujisaki, Katsuo, Ohta, Yukimaru, Kobayashi, Toshiaki, and Hayashi, Haruyoshi}
abstractNote = {A two-phase flow has characteristics of the blockage instability in which voids prevent and stop the water flow in an inverted U-tube. In cooler c{sub 32} employing inverted U-tubes, changes of heat transfer performance, abnormal mechanical vibrations and corrosions on the surfaces of cooling tubes had been observed during the operations of HENDEL (Helium Engineering Demonstration Loop). It was assumed that the causes of these abnormal events were air stagnated in inverted U-tubes when cooling water was filled before HENDEL operation. A blockage instability of two-phase flow and stability boundaries were investigated with an experimental apparatus composed of water plenums and an inverted U-tube which is parallel to a bypass channel. `Dynamic air vent` and `Vacuum air vent` methods were additionally suggested to reject the stagnated air in the inverted U-tubes. As the results of experiments, the possibility of Dynamic air vent method was verified using the experimental apparatus. And, the usefulness of Vacuum air vent method was also demonstrated through the tests employing cooler C{sub 32} of HENDEL. (author).}
place = {Japan}
year = {1994}
month = {Feb}
}
title = {Study of air vent design for inverted U-tube type heat exchanger}
author = {Takada, Shoji, Shibata, Mitsuhiko, Kato, Mitio, Fujisaki, Katsuo, Ohta, Yukimaru, Kobayashi, Toshiaki, and Hayashi, Haruyoshi}
abstractNote = {A two-phase flow has characteristics of the blockage instability in which voids prevent and stop the water flow in an inverted U-tube. In cooler c{sub 32} employing inverted U-tubes, changes of heat transfer performance, abnormal mechanical vibrations and corrosions on the surfaces of cooling tubes had been observed during the operations of HENDEL (Helium Engineering Demonstration Loop). It was assumed that the causes of these abnormal events were air stagnated in inverted U-tubes when cooling water was filled before HENDEL operation. A blockage instability of two-phase flow and stability boundaries were investigated with an experimental apparatus composed of water plenums and an inverted U-tube which is parallel to a bypass channel. `Dynamic air vent` and `Vacuum air vent` methods were additionally suggested to reject the stagnated air in the inverted U-tubes. As the results of experiments, the possibility of Dynamic air vent method was verified using the experimental apparatus. And, the usefulness of Vacuum air vent method was also demonstrated through the tests employing cooler C{sub 32} of HENDEL. (author).}
place = {Japan}
year = {1994}
month = {Feb}
}