机械

针对核燃料微球传统人工装填效率低下的问题，提出一种基于微球倾倒原理的自动化装填方法，系统探究微球装载板孔深参数对燃料固定效果的影响规律。通过建立核燃料微球与盲孔装载板的三维力学模型，构建微球受力平衡方程，推导出临界脱落条件与孔深的理论关系。采用离散元EDEM仿真技术对0.20 mm、0.30 mm、0.4 mm三种典型孔深参数进行微球堆积行为模拟，结合力学分析确定孔深参数优选范围。基于仿真结果搭建自动化装填试验平台，设计多孔位同步装填机构实现微球均匀分布，开发视觉检测系统实时监控装填质量。实验结果表明：当装载板孔深为0.30 mm时，在保证微球外露体积的同时，可以满足装填率超过95%的设计要求。研究证实基于力学建模与EDEM离散元仿真的参数优化方法可有效指导核燃料装载板设计，提出的自动化装填方案为核电站燃料组件制备提供了新的技术途径。

To address the low efficiency of traditional manual filling for nuclear fuel microspheres, this study proposes an automatic filling method based on microsphere pouring principles, systematically investigating the influence of hole depth parameters in loading plates on fuel fixation effectiveness. By establishing a three-dimensional mechanical model of nuclear fuel microspheres and blind-hole loading plates, force equilibrium equations were constructed to derive the theoretical relationship between critical detachment conditions and hole depths. Discrete element EDEM simulations were employed to analyze microsphere stacking behaviors under three typical hole depths(0.20 mm, 0.30 mm, 0.32 mm), determining the optimal range of hole depth parameters based on mechanical analysis. An automatic filling experimental platform was developed based on simulation results, incorporating a multi-hole synchronous filling mechanism for uniform distribution of microspheres and a vision inspection system for real-time quality monitoring. Experimental results demonstrate that the hole depth of 0.30 mm achieves a filling rate exceeding 95% while maintaining proper microsphere exposure. This research validates the effectiveness of parameter optimization through mechanical modeling and EDEM simulations for nuclear fuel loading plate design, providing a novel technical approach for preparing fuel assemblies for nuclear power plants.