Thermal cycle power conversion for the ARIES-I tokamak reactor

The selection and analysis of a suitable power-conversion system for the Advanced Reactor Innovation and Evaluation Study-I (ARIES-I) tokamak fusion reactor are presented. Two main groups of thermal cycles have been investigated. One group is comprised of the nonconventional Brayton and Rankine dissociating-gas cycles using such reacting gases as nitrogen tetroxide (N₂O₄) and nitrosyl chloride (NOCl). The other group consists of the conventional inert-gas Brayton cycle and Rankine steam cycles. The dissociating-gas cycles have the potential to operate at higher temperatures and offer higher conversion efficiency and more compact design. However, because of the severe safety problems associated with the toxicity of N₂O₄ and NOCl, a dissociating-gas cycle was not selected. An inert-gas Brayton cycle, although more compact, offers much lower conversion efficiency compared to the Rankine steam cycle. The selected power-conversion system for ARIES-I is, therefore, based on advanced supercritical Rankine steam cycle with double reheat. A gross conversion efficiency of about 48% is predicted