Potential Improvements of Supercritical CO2 Brayton Cycle by Mixing Other Gases with CO2
(0) A Sodium-cooled Fast Reactor (SFR) is one of the strongest candidates for the next generation nuclear reactor. However, the conventional design of a SFR concept with an indirect Rankine cycle is subjected to a sodium-water reaction. To prevent any hazards from sodium-water reaction, a SFR with the Brayton cycle using Supercritical Carbon dioxide (S-CO2) as working fluid can be an alternative approach to improve the current SFR design. However, the S-CO2 Brayton cycle is highly sensitive to the critical point of working fluids than other Brayton cycles. This is because compressor work is significantly decreased slightly above the critical point due to high density near boundary between supercritical state and subcritical state. For this reason, the minimum temperature and pressure of cycle are just above the CO2 critical point. In other words, critical point acts as a limitation of the lowest operating condition of the cycle. Therefore, changing the critical point of CO2 can result in an improvement of the total cycle efficiency with the same cycle layout. A small amount of other gases can be added in order to change the critical point of CO2. Several gases that show chemical stability within the interested range of cycle operating condition were chosen as candidates for the mixture; CO2 mixing with N2, O2, He, and Ar. As a result, CO2-He binary mixture shows the highest cycle efficiency increase by 1.67 ％. Contrary to CO2-He binary mixture, the cycle efficiencies of CO2-Ar, CO2-N2, and CO2-O2 binary mixtures are slightly increased or remained the same compared to the pure S-CO2 cycle: 0.23 ％, -0.05 ％, and 0.11 ％, respectively.
S-CO2 cycle supercritical Brayton cycle gas mixture cycle CO2-He cycle shift of criticalpoint
Woo Seok Jeong Jong Hyuk Lee Jeong Ik Lee Yong Hoon Jeong Hee Cheon NO Ji Hwan Kim
Korea Advanced Institute of Science and Technology 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701, Nuclear Environment Technology Institute 25-1, Jang-dong, Yuseong-gu, Daejeon 306-110, Republic of K
国际会议
上海
英文
1954-1965
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）