基于CFD方法的熔盐储罐布液系统分析

Analysis of Molten Salt Storage Tank Distribution System based on CFD Method

熔盐储罐是光热电站以及熔盐储热项目储热系统安全运行的重要装置之一,通常为了确保罐内温度场均匀,储罐内部会增加布液环装置,目前对布液环喷嘴出口液体流动状态的研究内容较少,为了进一步研究经过布液环分布后熔盐从喷嘴喷出后的流动状态。以某实际熔盐储热调峰项目中熔盐储罐内布液环为研究对象,采用分层液位计算方案,基于计算流体动力学(CFD)方法,对储罐的布液系统进行数值模拟,探究罐体布液环结构在不同液位条件下,布液装置对罐内熔盐的混合程度的影响和液体喷射高度。结果表明:在最大流速、不同液位时,布液环均可对冷、热盐罐内的熔盐产生较好的搅动作用;不论多高液位,在布液环支管出口均会产生一定的高速流动,局部最高速度与罐体液位无关,与入口压力以及流速有关,且熔盐液会喷出液面,但喷出高度很低。

Molten salt storage tank is one of the important devices for the safe operation of the heat storage system of the solar thermal power station and the molten salt heat storage project. Usually in order to ensure the uniform temperature field in the tank, the liquid ring device will be provided inside the tank. In order to study the flow state of molten salt ejected from the nozzle after the distribution of liquid rings, taking the liquid ring in the molten salt storage tank in an actual molten salt storage and peak regulating project as the research object, the layered liquid level calculation scheme is adopted to simulate the liquid distribution system of the tank based on the computational fluid dynamics(CFD) method, and the influence of the liquid distribution device on the mixing degree of molten salt in the tank and the liquid injection height under different liquid level conditions are explored. The results show that at the maximum flow rate and different liquid levels, the liquid ring can have a good agitation effect on the molten salt in the cold and hot salt tank. No matter how high the liquid level, a certain high-speed flow will be generated at the outlet of the liquid ring branch pipe, and the local maximum speed has nothing to do with the liquid level in the tank, but is related to the inlet pressure and flow rate. In addition, the molten salt liquid will spray above the liquid level, but the spray height is very low.