碱金属工质在基于毛细泵回路的多孔芯蒸发器内的热质传输特性

以基于毛细泵回路(CPL)原理的多孔芯蒸发器为研究对象，耦合多孔芯、蒸汽槽道和蒸发器壳体等多个部件，通过数值模拟的方法对碱金属工质在蒸发器内部的流动和相变传热特性进行分析，得到蒸发器内部的气相体积分数、温度、压力以及速度等分布。结果表明:碱金属液体极高的导热系数使得多孔芯部分的平均过热度不足1K；以碱金属为工质的多孔芯蒸发器，其内部的蒸发属于表面蒸发，气液界面稳定在多孔芯和蒸汽槽道的界面处，且在相同参数条件下，其毛细抽吸力比使用传统工质的蒸发器高1~2个数量级，具有更大的传输能力。 

Heat and mass transfer characteristics of alkali metal working medium in porous wick evaporator based on capillary pumped loop

Taking porous wick evaporator based on the principle of capillary pumped loop (CPL) as object and considering the wick, vapor groove and casing as a whole, the heat transfer and phase change characteristics of alkali metal working fluid in the porous wick evaporator were analyzed by numerical simulation method. The distributions of vapor phase volume fraction, temperature, pressure and velocity of working medium were obtained. The results showed that the average superheat of porous wick was less than 1K due to high thermal conductivity of alkali metal liquid. The evaporation of alkali metal liquid took place at outside surface of the porous wick and the liquid vapor interface was maintained at wick groove interface. Under the same parameter conditions, the evaporator using alkali metal had greater transport capacity since its capillary force was 1 to 2 orders of magnitude higher than that of the evaporator using conventional working fluid.