烘干炉内易开盖升温特性试验及数值模拟研究

目的 易开盖刻线修补涂层在烘干过程中易出现气泡、开裂和剥落等问题，为此需对易开盖在烘干炉内的升温特性进行研究。方法 采用现场试验和数值模拟方法，首先对炉内温度分布及易开盖表面温度变化进行测定，随后基于CFD仿真技术，利用动网格模型对易开盖在炉内运动加热过程进行模拟，并采用动态边界条件对单片易开盖表面温度分布进行计算。结果 炉内温度变化特性为沿盖体运动方向先上升后下降，两侧各存在一个温度突降区域;易开盖在炉内加热过程呈现快速升温、缓慢升温和快速降温3个阶段，125、130和135 ℃ 3个烘干炉设置温度工况下，易开盖表面最高温度分别为148、152和155 ℃，温度越高涂层气泡越多;加热初期易开盖表面温差较大，最高达5 ℃，后期温差逐渐降低至1 ℃以下。仿真结果与试验数据吻合较好，平均相对误差MRE值为0.1。结论 获得了易开盖在炉内的升温特性及最优加热工况，同时构建了基于动网格模型的易开盖运动加热CFD仿真方法，对烘干炉的设计和运行具有指导意义。

Experiment and Numerical Simulation on Temperature Rise Characteristics of Easy-open Ends in Drying Furnace

Since the protective coating on easy-open ends frequently encounters challenges like bubbling, fissures, and delamination during the drying process, the work aims to study the temperature rise characteristics of easy-open ends in the drying furnace. By combining on-site experiments and numerical simulations, the thermal distribution within the furnace and the surface temperature variations of the easy-open ends were measured. Subsequently, based on CFD simulation technology, a dynamic mesh model was employed to intricately replicate the thermal evolution experienced by the moving easy-open ends inside the furnace. Additionally, dynamic boundary conditions were employed to meticulously calculate the surface temperature distribution of each individual easy-open end. The temperature change in the drying furnace was characterized by an initial temperature increase followed by a subsequent decrease, mirroring the motion of the easy-open ends and there were prominent temperature drop regions on both sides of this trajectory. The thermal transformation experienced by the easy-open ends within the drying furnace could be divided into three phases of rapid heating, gradual heating, and swift cooling. Under three distinct drying furnace temperature settings (125 °C, 130 °C, and 135 °C), the maximum surface temperature of the easy-open ends progressively reached 148 °C, 152 °C, and 155 °C, respectively, indicating a direct correlation between higher temperature and increased bubble formation in the coating. During the initial heating phase, there was a notable temperature difference across the surface of the easy-open ends, peaking at 5 °C, which gradually diminished to below 1 °C in later stages. The simulation results were consistent with the experimental data, with an average MRE of just 0.1. This comprehensive study not only obtains the thermal characteristics and optimal heating conditions for easy-open ends within the drying furnace but also establishes the groundwork for CFD simulation approach of easy-open end motion heating grounded in a dynamic mesh model, providing invaluable guidance in the design and operation of drying furnaces.