Primary Study of Steady States of HTGR-GT

The High Temperature Gas-cooled Reactor coupled with gas turbine (HTGR-GT) is supposed to be one of the candidates for the future nuclear power plants in both electricity and hydrogen production. The HTGR-GT cycle is theoretically based on the closed Brayton cycle with recuperator, intercooler and precooler. In this paper, the exergy analysis on a typical HTGR coupled with Gas Turbine was presented. Besides the core outlet temperature of the cycle, other operating parameters have been calculated to see their effect of the exergy efficiency of the whole cycle. The results show that, the compressor pressure ratio (γ) of the cycle has a great effect on the exergy losses of both heat-exchange and work components. And only the exergy loss of the recuperator decreases with the increase of γ, especially sharply when γ is small, while the exergy losses of other components increases. So there are optimized γ under different working conditions. The effect of other operating parameters, like pressure drop, recuperation efficiency and isentropic efficiencies of compressors and turbine, has been evaluated. The effect of two formers is similar, both obvious at the range of near the optimized γ, and γ goes down slightly when these two operating conditions are better. Compressors and turbine, as the work components of the cycle, their isentropic efficiency is quite important to the exergy efficiency of the cycle. The bigger γ, the more effect. Whatever, the isentropic efficiency of compressors and turbine is already quite high.