The design and performance analysis of highly loaded compressor of closed Brayton cycle HTGR power plant with helium xenon gas mixture as working fluid

This paper evaluates the use of helium xenon binary gas mixture having molecular weight of 15 g/mole in an axial compressor of terrestrial nuclear power plants as working fluid. Pure helium is one of the best coolants due to its superior transport properties, however it is difficult to compress. Its use in high temperature gas cooled reactor (HTGR) energy conversion system leads to bigger size, more mass, higher cost and cause dynamic problems in turbomachines. In this study, detailed analysis of thermophysical properties of the binary gas mixture of helium xenon shows that the helium xenon mixture having 15 g/mole molecular weight has 7% higher heat transfer coefficient at requisite pressure and temperature. Subsequently, highly loaded helium xenon compressor is designed and performance analysis is conducted. This concludes that, only 20% stages of those in helium compressor are required to compressed the gas to the desired pressure in highly loaded helium xenon compressor. The compressor of high temperature gas cooled reactor (HTGR) working on Closed Brayton Cycle (CBC) reduced to 3 against 16 stages. Thus, in turbocompressors of HTGR power plants, use of helium xenon over pure helium is advantageous.