GENERAL COMMENTS ABOUT THE EFFICIENCY OF THE IODINE-SULPHUR CYCLE COUPLED TO A HIGH TEMPERATURE GAS-COOLED REACTOR

摘要

Several theoretical papers deal with the efficiency of the thermochemical cycles. In 1966, Funk and Reinstrom established the conditions to fulfill in order that no work is required by the cycle. They investigated a cycle comprised of two reactions and concluded that it was not feasible. In 1974, Abraham and Schreiner found that a minimum of three reactions were required if the maximum temperature is lower than 1 000 °K, and proposed the entropy vs. temperature diagram analysis to evaluate the thermochemical cycles. Finally, in 1975 Esteve, Lecoanet and Roncato presented a simplified method to estimate the efficiency of a cycle. Each endothermic reaction is assumed to be achieved at a constant temperature for which ΔG=0. This enables a calculation of the thermal irreversibility due to the exchanges of heat with the intermediate circuit of the reactor. Until now, none of these theories have been applied to the well known Iodine Sulphur (I-S) cycle. The objective of the paper is to put in evidence the conclusions that can be drawn from the application of these theoretical results to the I-S cycle, and in particular what efficiency bounds one can reasonably expect.