熔盐单罐蓄热系统中斜温层黏性指进的稳定性分析

发布时间：2019-01-23 09:29

【摘要】：单罐填充床蓄热是一种重要的高温蓄热方式,而在充放热过程中不发生黏性指进现象,保持斜温层的稳定是蓄热系统是否可行的重要依据。本文对充放热过程中熔盐的流动方向、熔盐的密度和黏度对黏性指进的影响进行了详细的理论分析。结果表明熔盐自上而下流动,热熔盐置换冷熔盐时,熔盐流速不能超过临界流速;冷熔盐置换热熔盐时,熔盐流速要大于临界流速才能维持斜温层的稳定。熔盐自下而上流动,热熔盐置换冷熔盐时,必然会发生黏性指进;冷熔盐置换热熔盐时,没有流速的限制,斜温层能自然保持稳定。
[Abstract]:Single tank packed bed heat storage is an important way of high temperature heat storage, but there is no viscous fingering phenomenon in the process of heat filling and releasing. Keeping the stability of inclined temperature layer is an important basis for the feasibility of heat storage system. In this paper, the flow direction of molten salt, the influence of density and viscosity of molten salt on viscosity fingering are analyzed in detail. The results show that the flux of molten salt flows from top to bottom. When hot melt salt is replaced by cold molten salt, the flow rate of molten salt can not exceed the critical velocity, and the velocity of molten salt should be higher than the critical flow rate in order to maintain the stability of inclined temperature layer when cold molten salt is replaced by hot melt salt. When molten salt flows from bottom to top, when hot melt salt is replaced by cold molten salt, viscosity will inevitably come into being, and when cold molten salt is replaced by hot melt salt, the oblique temperature layer will naturally remain stable without the restriction of flow rate.
【作者单位】：东莞理工学院广东省分布式能源系统重点实验室;
【基金】：国家自然科学基金项目(No.51306039) 广东省自然科学基金项目(No.2015A030313655)
【分类号】：TM615

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