A thermodynamic analysis of high temperature gas-cooled reactors for optimal waste heat recovery and hydrogen production

In this study the concept of generalized cogeneration has been employed to the analysis of the effective heat recovery from the high temperature gas-cooled reactor (HTGR). Brayton cycle is used as a topping cycle for HTGR with helium as the working fluid. HTR-10 and VHTR, having different power levels of HTGR, have been applied in the present study. The paper investigates the optimal strategy of the heat recovery, which combines the bottoming cycles and the parameters such as the select of different working fluids and the ambient temperatures. The heat recovery has integrated the organic Rankine cycle (ORC) using the fluids, such as alkane and benzene to perform the thermodynamic analysis. The total efficiency could be increased by 13.57% and 3.12% for HTR-10 and VHTR, respectively. Brayton cycle has been employed in the heat recovery for the iodine-sulfur (IS) hydrogen production process of VHTR by integrating the intermediate cooling process with the recuperator. When the sulfur trioxide (SO₃) decomposition temperature is the lowest and the efficiency of the power conversion from hydrogen is assumed 0.6, the total thermal efficiency will be increased from 3.12% to 8.60%. © 2012 Elsevier Ltd.