对于多孔吸湿性的尿素颗粒,由于其颗粒内部存在大量的孔隙和具有挥发性,传统的热重力测湿法并不适宜定义其含湿量。该文通过构建一套实验装置并运用卡尔费歇滴定法定义了尿素堆的真实水含量。提出了结合水蒸气扩散和液膜迁移的数值模型并模拟了湿分的迁移。模拟结果和试验测试数据吻合较好。卡尔费歇滴定法是一种可行的定义颗粒堆水含量的方法。所展示的模型有望作为实际的工具预测多孔尿素堆中湿分的传输。 For porous hygroscopic urea particles, traditional thermogravimetry is not suitable for the determination of moisture content because of the large number of pores and the volatility of the particles. This paper defines the true water content of a urea reactor by constructing a set of experimental devices and applying Karl Fischer titration. A numerical model combining water vapor diffusion and liquid film migration is proposed and the migration of moisture is simulated. The simulation results agree well with the experimental test data. Karl Fischer titration is a viable method of defining the water content of particles. The model presented is expected to serve as a practical tool for predicting moisture transfer in porous urea stacks.