结冰过程固液相变的传热分析推荐.doc

Ⅱ 华北电力大学本科毕业设计（摘要） PAGE I 结冰过程固-液相变的传热研究 摘要 水在冷空气流中凝固问题的研究对于实际的生产生活有着深远意义，例如：提高节能技术，避免飞机飞行过程中的结冰以保证飞行安全性，冰蓄冷空调系统中蓄冰槽内的蓄冰、融冰，延长食品的保存期，深入了解地球科学等。 水在冷空气流中凝固，是包含两种相变过程的传热传质、伴随两个移动边界的复杂问题，并且两个边界相互影响、相互耦合。本文采用分区域模型，分别建立固、液两相的能量方程和传质方程，采用控制容积积分法进行网格差分，并运用移动网格技术追踪界面运动情况。在此基础上利用Fortran语言程序进行计算，对不同工况下的传热传质规律进行结果分析，获得了空气流速和液滴尺寸对结冰过程的影响规律，并掌握了液滴中心和表面温度的分布状况。本文对进一步研究液滴结冰过程的传热传质规律具有参考价值。 关键字：结冰；固-液相变；传热；移动界面 华北电力大学本科毕业设计（abstract） PAGE II Investigation of Heat Transfer of Solid-Liquid Phase Change during Freezing Process Abstract The problem of water solidification in cold air flow has far-reaching implication for the actual production and living, such as: improving energy-saving technologies, to avoid the aircraft icing problem during flight to ensure the flight safety, the storage of ice or the melting of ice for the ice storage air conditioning system, to extend the shelf life of food, in-depth understanding of the earth sciences and so on. Water solidification in cold air flow involves two phase heat transfer and the mass transfer process, along with the complexity of the two moving boundary problem, and the two interfaces couple with each other. This paper, sub-regional model was used to establish the energy equation and mass transfer equation of the solid and liquid phases. Besides, the volume control integration method was used for differential, and the moving mesh technology was applied to track the movement of the interfaces. On this basis, the fortran programming language is used to calculate the model. The calculation results are analyzed under different conditions. The influences of air flow rate and droplet size on the droplet freezing process are obtained, and also the temperature distribution in the droplet center and at the droplet surface is researched. This paper has reference value for further investigation of heat and mass transfer during the process of droplet freezing. Keywords: freezing; solid - liquid phase change; heat transfer; moving interface   华