方管与圆管中石蜡蓄热的对比研究

Comparative study of paraffin heat storage in rectangular and circular tubes

中文关键词: 石蜡熔化  方形管道  圆形管道  自然对流  数值模拟

英文关键词: paraffin melting  square tube  circular tube  natural convection  numerical simulation

中文摘要:

      针对不同形状管道对蓄热状况影响不同，建立了圆形管道与方形管道的石蜡蓄热模型，运用FLUENT软件对其熔化过程进行了仿真，讨论了自然对流及石蜡厚度对石蜡蓄热的影响。计算结果表明：熔化初期，方形装置内的固液界面呈“脚丫”状，而圆形装置内的固液界面近似呈椭圆状。自然对流对熔化结果影响较大，对流的存在加速了石蜡的熔化；在自然对流的作用下石蜡的熔化速率先快后慢，而熔化总时间与石蜡厚度成正相关。在蓄热单元面积保持不变的情况下，当内管周长相等时，方管内石蜡熔化总时间大于圆管内石蜡熔化总时间；当内管面积相同时，方管内石蜡熔化总时间小于圆管内石蜡熔化总时间。

英文摘要:

      A paraffin heat storage model for circular and square pipes was established. The melting process was simulated by FLUENT software. The effects of natural convection and paraffin thickness on paraffin heat storage were discussed. The results show that the solid-liquid interface at the preliminary stage of melting is in the shape of a “foot” in the square device, while the solid-liquid interface in the round device is approximately elliptical. Natural convection has a great influence on the melting results, and the existence of convection accelerates the melting of paraffin wax. Under the action of natural con-vection, the melting speed of paraffin wax started very fast and then gradually slowed down, and the total melting time is positively correlated with the thickness of paraffin wax.Keeping the area of heat storage unchanged, the total melting time in square device is longer than that in round device with the same circumference of inner tube, but the result is opposite while the areas of inner tubes are the same.