【作者】 熊亚选； 李烁； 胡晓； 彭笑东； 张慧； 吴玉庭；

【Author】 XIONG Yaxuan;LI Shuo;HU Xiao;PENG Xiaodong;ZHANG Hui;WU Yuting;

【机构】 北京建筑大学供热供燃气通风及空调工程北京市重点实验室； 全球能源互联网研究院； 北京工业大学传热强化与过程节能教育部重点实验室；

【摘要】 熔盐储热罐中熔盐熔化的过程中,熔盐发生着从固态到过渡态再到液态的相变过程。针对谷电储热的MW级双罐系统中熔盐的熔化过程,建立储热熔盐相变过程的数学物理模型,采用计算流体动力学方法,研究实际场景电加热器恒温加热条件下高温熔盐熔化过程中的传热储热性能。结果表明,熔盐从固态受热、熔化至液态的过程经历了固态导热、相变传热、自然对流传热等三个阶段;从熔化过程的动态温度云图发现,熔化过程的熔盐温度出现了明显的温度分层现象;从流场动态矢量云图发现,熔盐加热熔化的过程中围绕加热器呈对称涡旋式流动;传热Nusselt数随时间缓慢回升的时刻即为传热从导热向自然对流转换的时刻,储热量可以反映传热的效果。此外,不同的加热器温度,会造成熔化时间的不同,温度升高,熔化速率加大。更多还原

【Abstract】 Based on binary mixed nitrate as heat storage material, in view of the valley of the electric heating MW level high temperature molten salt storage system, established the heat storage tank of high temperature molten salt phase change process of mathematical physical model, using computational fluid dynamics method,the actual scene electric heater thermostat heating under the condition of high temperature molten salt melting heat transfer in the process of thermal storage performance. The results show that the molten salt experiences three stages: solid heat conduction, phase change heat transfer and natural convection heat transfer. From the dynamic temperature nephogram of melting process, it is found that the molten salt temperature appears obvious temperature stratification phenomenon. It is found from the dynamic vector nephogram of the flow field that the molten salt flows in a symmetrical eddy around the heater during the heating and melting process. The time when the Nusselt number, which represents the heat transfer performance, slowly rises with time is the time when the heat transfer is transferred from heat conduction to natural convection. Heat storage can reflect the effect of heat transfer. In addition, different heater temperature will cause different melting time, melting rate will increase as the temperature increases.更多还原