流体温度及流速对铝管内石蜡传热性能的影响

分析了铝管外换热流体温度及流速对铝管内石蜡储放热性能的影响,并通过简化石蜡相变模型,反推得到放热过程中液相石蜡区域半径。结果表明:风速越大,储热时间越短,最短的储热时间为1 380 s,属于温度为80℃、风速为3 m/s的情况;在一定温度下,风速越大,管壁温度下降越快,放热时间越短;通过反推液相区半径发现,风速越小,石蜡凝固越慢,放热结束时的液相区越大;最小液相半径出现在空气温度为80℃,风速为1.5 m/s的情况下,其值为4.19 mm。

The effect of air temperature and velocity on heat-conducting property of paraffin filled in aluminum tubes

The effect of air temperature and air velocity on heat transfer performance was studied in this paper.The radius of liquid zone was obtained with inverse method based on a simplified phase-change model.The results show that: the larger the wind speed,the time to store heat is shorter.The shortest time is 1 380 seconds with 80 ℃ air temperature and 3 m/s air speed;In a certain temperature,the larger the wind speed,the more rapidly the tube wall temperature drops and the shorter the exothermic time is;It is found from radius calculation that the lower the wind speed,the more slowly the paraffin solidifies and the larger the area of liquid zone is at the end of exothermic process;The least radius of paraffin liquid zone is 4.19 mm with 80 ℃ air temperature and 1.5 m/s air speed.