ICONE23-1057 PARAMETRIC STUDIES ON THERMAL CYCLE OF HTGR WITH HE-CO_2 MIXED WORKING MEDIUM

Abstract

High temperature gas-cooled reactor (HTGR) with direct gas turbine cycle has the potential advantages of high cycle efficiency. It uses the high temperature gas generated by the reactor core to work directly, breaking the limitation of the low gas temperature of Rankine cycles in traditional reactors. In most former studies, the working medium used in the cycle is Helium (He), and there are few researches about the influence of mixed working medium on the cycle efficiency. In this paper, the thermal cycle efficiency is calculated under the condition of different mixing ratio, to analyze the influence from different parameters such as compression ratio. The results show that the optimum molar fraction of CO_2 can be made reasonably through considering all the influence factors, to maximize the cycle efficiency. And increasing the ratio of CO_2 and Helium can significantly improve the dropping trend of the cycle efficiency under the high compression ratio. In the meantime, however, the cycle pressure loss caused by the increase of CO_2 should be considered as well.