TY - GEN
T1 - Experimental study of gas accumulation according to changes of temperature and pressure
AU - Jo, Hongrae
AU - Song, Yong Jae
AU - Jo, Daeseong
N1 - Publisher Copyright:
Copyright © 2018-2019 by JSME
PY - 2019/5/18
Y1 - 2019/5/18
N2 - The existence of gas inside the safety system results in damaging system components, reducing cooling performance and increasing unreliableness of system analyses. Thus, the unexpected gas accumulation must be prevented and the accumulated gas must be removed. In order to avoid the gas accumulation, it is necessary to understand the mechanism how the phenomenon occurs. In the present research, it was observed quantitatively how the gas accumulation was generated by dissolved gas separation during changes of temperature and pressure. The experimental study was conducted in stationary water under (1) various pressure in isothermal condition and (2) various temperature in isobaric condition. Before experiments, the water was maintained in the atmospheric pressure and the temperature of 20 ℃, more than 24 hours for initial condition. For isothermal experiment, the water in the atmospheric pressure was pressurized to higher pressure. Thereafter, the pressurized water returned to the atmospheric pressure. The temperature was kept in 20 ℃. During pressurization or depressurization, the dissolved gas was not separated and accumulated due to the solubility of gas was always higher than that of initial condition. For isobaric experiment, the water was heated from 20 ℃ to the higher temperature under the atmospheric pressure. When the water was heated, the temperature was kept in certain temperature for enough time. When the water was maintained at higher temperature, gas was separated and accumulated because the solubility of gas became lower in higher temperature. However, even if the water was cooled, the accumulated gas was not dissolved 100 % again and more than 50 % of gas remained. As the experimental results, gas can be separated and accumulated when the solubility of gas is lower than that of the initial condition. Also, when the gas accumulation occurs, the residual gas cannot be removed without additional processes. For prevention of gas accumulation, temperature and pressure should be controlled by appropriate procedures to keep the gas solubility higher than initial condition.
AB - The existence of gas inside the safety system results in damaging system components, reducing cooling performance and increasing unreliableness of system analyses. Thus, the unexpected gas accumulation must be prevented and the accumulated gas must be removed. In order to avoid the gas accumulation, it is necessary to understand the mechanism how the phenomenon occurs. In the present research, it was observed quantitatively how the gas accumulation was generated by dissolved gas separation during changes of temperature and pressure. The experimental study was conducted in stationary water under (1) various pressure in isothermal condition and (2) various temperature in isobaric condition. Before experiments, the water was maintained in the atmospheric pressure and the temperature of 20 ℃, more than 24 hours for initial condition. For isothermal experiment, the water in the atmospheric pressure was pressurized to higher pressure. Thereafter, the pressurized water returned to the atmospheric pressure. The temperature was kept in 20 ℃. During pressurization or depressurization, the dissolved gas was not separated and accumulated due to the solubility of gas was always higher than that of initial condition. For isobaric experiment, the water was heated from 20 ℃ to the higher temperature under the atmospheric pressure. When the water was heated, the temperature was kept in certain temperature for enough time. When the water was maintained at higher temperature, gas was separated and accumulated because the solubility of gas became lower in higher temperature. However, even if the water was cooled, the accumulated gas was not dissolved 100 % again and more than 50 % of gas remained. As the experimental results, gas can be separated and accumulated when the solubility of gas is lower than that of the initial condition. Also, when the gas accumulation occurs, the residual gas cannot be removed without additional processes. For prevention of gas accumulation, temperature and pressure should be controlled by appropriate procedures to keep the gas solubility higher than initial condition.
KW - Dissolved Gas
KW - Gas Accumulation
KW - Generic Letter 2008-01
KW - Non-condensable Gas
KW - Safety System
UR - http://www.scopus.com/inward/record.url?scp=85071369158&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:85071369158
T3 - International Conference on Nuclear Engineering, Proceedings, ICONE
BT - Proceedings of the 27th International Conference on Nuclear Engineering, ICONE 2019 - "Nuclear Power Saves the World!"
PB - American Society of Mechanical Engineers (ASME)
T2 - 27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019
Y2 - 19 May 2019 through 24 May 2019
ER -