For nuclear-driven thermochemical hydrogen production, a key limitation of existing systems is that the Cu-Cl cycle and ORC waste-heat recovery unit are typically optimized independently, a practice that can overlook their thermal interactions and result in suboptimal overall performance. To address this mismatch, this study proposes a hybrid optimization framework for an HTR-PM/Cu–Cl/ORC hydrogen and power cogeneration system. The framework integrates pinch analysis for heat exchanger network reconstruction with a multilayer perceptron surrogate model for ORC performance prediction, enabling decoupled two-stage optimization of both subsystems. When applied to the integrated system, the optimized heat exchanger network reduces hot and cold utility demands by 44.16% and 44.24%, respectively. The proposed optimization framework improves the overall exergy efficiency from 22.2% to 26.2%, while increasing the ORC net power output to 56.0 kW at a constant hydrogen production rate of 1.0 mol/s. The MLP surrogate model reduces ORC optimization time from approximately 120 h to less than 10 min. These results suggest that addressing the Cu–Cl/ORC mismatch through the proposed optimization can enhance both the thermodynamic and economic performance of nuclear-assisted hydrogen production systems, supporting more efficient cascade utilization of nuclear heat and offering a potential pathway for engineering implementation.
The helical cruciform fuel (HCF) element is a critical component in the design of next-generation nuclear reactors due to its enhanced heat transfer area and coolant mixing capabilities. However, the accumulation of corrosion products, known as CRUD, on the fuel cladding surface significantly compromises reactor safety and operational efficiency by increasing thermal resistance. This study utilizes the ANSYS FLUENT computational framework, integrated with a customized User-Defined Function (UDF) deposition–erosion model, to simulate CRUD behavior within a 4*4 HCF channel array. This numerical results reveal that CRUD deposition exhibits a highly non-uniform spatial distribution, with the maximum thickness occurring on the windward side near the channel entrance. This accumulation creates an additional thermal barrier that increases the fuel cladding surface temperature by up to 12.6 K under baseline operating conditions. Parametric analysis demonstrates that the peak CRUD thickness decreases with higher coolant inlet velocities and wall heat fluxes, whereas it increases substantially as the inlet temperature rises. The findings provide a comprehensive quantitative assessment of CRUD-induced thermal–hydraulic degradation in HCF elements, offering vital insights for the optimization of reactor safety margins and performance in advanced pressurized water reactors.
