目的 研究颗粒在等离子体喷涂中的加热过程及影响因素。方法 使用Fluent软件对处于等离子射流中颗粒的加热过程与状态进行求解计算，根据计算结果分析了喷距、颗粒直径与颗粒材料对颗粒加热状况与内部温度梯度的影响。结果 对于不同的喷距，在颗粒升温过程中，颗粒表面温度高于中心温度；在颗粒降温过程中，颗粒表面温度低于中心温度，并且降温过程中的表面-中心温差远小于升温过程中的表面-中心温差。在颗粒升温过程中，其内部存在不同的加热阶段。对于不同的直径，虽然大颗粒比小颗粒能进入射流中心更深的位置，但小颗粒的加热效果更好。表面-中心温差随着颗粒直径的增大而增大，三种不同直径的颗粒的表面-中心温差变化曲线都表现出相似的趋势。对于不同材料的颗粒，热导率越低的颗粒，其表面-中心温差越高，越难以完全熔化。结论 喷距、颗粒直径与颗粒材料对颗粒加热状况和内部温度梯度有很大的影响，该模拟结果能为分析颗粒与等离子体之间的传热提供参考。

Objective To study the heating process of particles in plasma spray and influence factors. Methods The heating process and state of particles in plasma spray was calculated by Fluent software. Then the effect of standoff distance, diameter and materials of particles on the heating condition and temperature gradient of particles was analyzed based on the calculation results. Results During the heating process of particles under different standoff distances, the surface temperature of particles was higher than the center temperature of particles. In the cooling process, the center temperature was lower than the surface temperature and the surface-center temperature difference was far less than that in the heating process. There were different heating stages in heating process. For different diameters of particle, small particles could obtain better heating than the bigger one, although the bigger one could enter a deeper position in the center than the smaller one. The surface-center temperature difference increased with the raising of particle diameter. And particles with three different diameters had the similar tendency of the surface-center temperature difference. In regard to different materials, the materials with lower thermal conductivity had higher surface-center temperature difference, thus that would be harder for melting of particles completely. Conclusion Heating condition and temperature gradient of particles are sharply influenced by standoff distance, diameter of particles and materials of particles. And this simulation results can provide reference for the analysis of heat transfer between particles and plasma.