三相流闭式重力热管的强化传热

Heat transfer enhancement in three-phase flow closed gravity heat pipe

将三相流强化传热技术应用于重力热管,构建了三相流闭式重力热管系统。以水为工质,固含率(体积分数)、固体颗粒的种类、大小及加热功率等作为参数,研究并分析了三相流重力热管的传热性能。结果表明:在一定的条件下,三相流闭式重力热管具有一定的强化传热效果。随着加热功率的增加,等效对流传热系数增大。加入5.5 mm的聚甲醛颗粒时,由于其不易流化,因此其固含率的变化对等效对流传热系数无明显影响;而当加入较易流化的3.15 mm的聚甲醛颗粒和树脂颗粒时,随着固含率的增加,其等效对流传热系数先增大,在到达某一定值后开始出现波动。

A three-phase flow heat transfer enhancement technique was applied to closed gravity heat pipe,and a set of three-phase flow gravity heat pipe system was set up.With water as working fluid and the solid holdup（volume fraction）,kinds of solid particles,the size of solid,and the heating power as operating parameters,the heat transfer performance of three-phase flow gravity heat pipe was investigated and analyzed.The equivalent convective heat transfer coefficient was used to assess the heat transfer performance.The results indicate that under the certain conditions,the three-phase flow gravity heat pipe has a better heat transfer enhancement,and the equivalent convective heat transfer coefficient increases with the increasing of heating power.When adding poor-fluidized 5.5 mm polyformaldehyde particles,the solid holdup has no obvious effect on the equivalent convective heat transfer coefficient;but when adding the better-fluidized 3.15 mm polyformaldehyde particles and resin particles,with the increasing of the solid holdup,the equivalent convective heat transfer coefficient first increases and then begins to fluctuate after reaching a certain value.