On the exergoeconomic assessment of employing Kalina cycle for GT-MHR waste heat utilization

Highlights: • Utilization of waste heat from GT-MHR for power generation by the Kalina cycle. • Exergoeconomic comparison of the proposed combined cycle with standalone GT-MHR. • Enhanced exergoeconomic performance for the combined cycle compared to the GT-MHR. • Comparable investment costs for the combined cycle and the standalone GT-MHR. - Abstract: Exergoeconomic concept is applied to compare the performance of the Gas Turbine-Modular Helium Reactor (GT-MHR) plant with a proposed combined GT-MHR/Kalina cycle in which the waste heat from the GT-MHR is recovered by the Kalina cycle for power generation. Thermodynamic and exergoeconomic models are developed to investigate the cycles' performance and assess the unit cost of the products. A sensitivity analysis is performed prior to the optimization of the cycles' performances from the view points of thermodynamics and economics. The results indicate that, when the performances of the two cycles are optimized economically, the efficiency and total product unit cost of the combined cycle is 8.2% higher and 8.8% lower than the corresponding values for the GT-MHR. It is interesting to note that, under these conditions, the total investment cost rate for the combined cycle is just slightly higher than that of the stand alone GT-MHR