Thermodynamic analysis of a combined modified kalina–GT-MHR cycle with porous medium effects

Efficient utilization of waste heat in advanced nuclear power systems has become a major research focus in modern energy engineering. This study proposes a novel thermodynamic configuration that integrates a Modified Kalina Cycle (KC) with a Gas Turbine–Modular Helium Reactor (GT-MHR) system while incorporating the effects of porous medium heat transfer in heat exchanger components. In the proposed configuration, waste heat rejected from the GT-MHR Brayton cycle is recovered to drive the Kalina cycle, thereby improving the overall system performance. A detailed energy and exergy analysis is carried out to evaluate the thermodynamic performance of the integrated system. The governing equations are formulated using conservation laws of mass, momentum, and energy, while porous medium effects are incorporated using the Darcy–Forchheimer model. The thermodynamic simulations are performed using Engineering Equation Solver (EES). Furthermore, a parametric investigation is conducted to analyze the influence of ammonia concentration, separator pressure, vapor generator temperature, and compressor pressure ratio on system performance. To obtain optimal operating conditions, the system thermal efficiency is maximized using a Genetic Algorithm optimization technique. The results indicate that the integrated system achieves a maximum thermal efficiency of 53.2% under optimal operating parameters. The energy and exergy analyses reveal that the reactor core contributes the highest exergy destruction rate, followed by the heat exchangers. The presence of a porous medium enhances heat transfer rates and improves thermal energy recovery. The results demonstrate that the proposed porous-enhanced Kalina–GT-MHR combined cycle exhibits higher energy efficiency and improved waste heat recovery compared with conventional stand-alone cycles. The study provides useful insights for the development of high-efficiency nuclear-assisted power generation systems.

Keywords: Power Generation System (PGS), Modified Kalina Cycle (KC), Gas Turbine Modular Helium Reactor (GT-MHR), Porous Medium Heat Transfer, Energy and Exergy Analysis (EEA), Parametric Investigation (PI), Genetic Algorithm Optimization.