CFD-Based Thermal Optimization of a High-Efficiency Boiler for Paddy Rice Parboiling in Rural Agro-Processing Systems

Parboiling remains a critical pre-processing stage in rice production, especially in Nigeria, where traditional methods are inefficient, labour-intensive, and often result in poor rice quality. This study presents the design and computational fluid dynamics (CFD) analysis of a novel rice parboiling boiler intended to improve energy efficiency and product quality for small-scale rural processors. Using PTC Creo for 3D modelling and ANSYS Fluent 2021 R1 for simulation, the thermal and fluid dynamic performance of the proposed boiler was evaluated under steady-state conditions. Tetrahedral meshing with boundary layer refinement was employed to resolve critical flow gradients, while a realizable k–ε turbulence model was adopted to capture complex internal flow characteristics. Simulation results revealed improved temperature uniformity, smoother fluid flow, and enhanced heat transfer due to the presence of internal baffles. Key performance parameters—including temperature distribution, pressure profile, turbulence kinetic energy, enthalpy, and mass flux—were analysed to validate the design’s effectiveness. The boiler achieved a thermal efficiency of 89.95%, demonstrating significant improvements over conventional parboiling systems. This research fills a notable gap in the application of CFD for rice parboiling boiler optimization, offering a cost-effective and energy-efficient solution tailored for rural deployment in developing countries. The findings provide a foundation for future design enhancements and sustainable agro-processing technologies.