管内加装电伴热装置时熔盐熔化过程研究  

Study on melting process of molten salt in pipe equipped with a built-in electric tracing heater

作　　者：吴旺松 匡敬柱 毛正江 曾勇 徐顺塔 刘豪[2] WU Wangsong;KUANG Jingzhu;MAO Zhengjiang;ZENG Yong;XU Shunta;LIU Hao(Powerchina Zhongnan Engineering Corporation Limited,Changsha 410014,China;State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]中国电建集团中南勘测设计研究院有限公司,湖南长沙410014 [2]华中科技大学煤燃烧国家重点实验室,湖北武汉430074

出　　处：《热力发电》2022年第3期79-87,共9页Thermal Power Generation

基　　金：中国电力建设集团有限公司重大专项课题(DJ-ZDZX-2018-02)。

摘　　要：建立了一种可实现直接接触式加热的电伴热熔盐管道二维模型,并模拟了管内二元熔盐的解冻熔化过程,分析了不同电伴热装置布置位置、尺寸和功率条件下熔盐熔化过程的均匀性和效率。结果表明:在自然对流作用下,电伴热装置附近先熔化的熔盐逐渐向管道上方迁移并汇聚到顶端;当电伴热装置功率为47.1 W/m时,其安装位置与重力方向的夹角约为30°时,熔盐解冻过程均匀性更好,熔化时间更短(约270 min);电伴热装置直径从10 mm增加到30 mm,熔盐熔化过程中温度均匀性提升了31.2%,完全熔化所需的时间缩短了54.6%;在实际熔盐管内电伴热的安装和设计中,电伴热装置安装位置与重力方向的夹角应为30°~90°较宜,并在满足工艺需求的同时尽可能扩大电伴热直径,以改善熔盐熔化过程的均匀性和效率。A two-dimensional model of the horizontal pipe that can heat binary molten salt through a built-in electric tracing heater is constructed. The melting process of molten salt in the pipe is numerically simulated, and the uniformity and efficiency for the melting process of molten salt are analyzed under different layout locations, sizes,and powers of the electric tracing heater. The results show that, affected by natural convection, the melting molten salt near the electric tracing heater flows to the upper space of the pipe gradually and converges to the top of the pipe. When the power of the electric tracing heater is 47.1 W/m and the angle between its installation position and the gravity direction is approximately 30°, the uniformity for the thawing process of the molten salt is better and the melting time is shorter(about 270 min). As the diameter of the electric tracing heater is increased from 10 mm to 30 mm, the temperature uniformity of the molten salt melting process is improved by 31.2% and the time required for complete melting is reduced by 54.6%. It is suggested that during the design and installation of an electric tracing heater in the molten salt pipe, the angle between the electric tracing heater location and the gravity direction should be better at 30°~90°, and the diameter of the electric tracing heater should be enlarged as much as possible while meeting the process requirements, to improve the uniformity and efficiency for the melting process of molten salt.

关 键 词：光热电站 直接接触式加热 熔盐熔化过程 温度均匀性 加热效率 数值模拟 

分 类 号：TK511[动力工程及工程热物理—热能工程]