化工学报 ›› 2008, Vol. 59 ›› Issue (6): 1360-1365.

• 传递现象 • 上一篇    下一篇

石蜡在管外凝固过程的理论和实验分析

张奕;张小松   

  1. 东南大学能源与环境学院;南京师范大学动力工程学院
  • 出版日期:2008-06-05 发布日期:2008-06-05

Theoretical and experimental study on solidification
of paraffin outside coil tube

ZHANG Yi;ZHANG Xiaosong   

  • Online:2008-06-05 Published:2008-06-05

摘要: 对使用水作为传热流体的蛇形管式换热器中,进口水温对石蜡在管外凝固过程的影响进行了研究。建立了水温沿流向变化,石蜡温度沿径向变化的传热模型。使用控制容积法及焓法建立了求解水和石蜡耦合温度场的数值方程,这两个温度场的计算结果与实验结果能很好吻合。冷却水进口温度不同,靠近铜管已凝固石蜡中的温度场存在显著差别,离铜管较远石蜡中的温度几乎不受进口水温影响,石蜡的无量纲温度场在离相界面较远处具有相似分布的特点。相界面移动具有先快后慢,然后再变快的特征。研究可为保证蛇形管外石蜡凝固速率选择恰当的进口水温提供计算方法。

关键词:

蛇形盘管, 进口温度, 传热过程, 石蜡, 凝固

Abstract:

The influence of inlet temperature of cooling water on the solidification of paraffin outside the coil tube was investigated.Numerical equations were set up to calculate the heat transfer inside the heat exchanger.The calculation of temperature fields of water and paraffin agreed well with experimental results.The temperature fields of paraffin near to the tube were different with different inlet temperatures of water,while the temperature fields far away from the tube were almost the same.The distribution of dimensionless temperature fields of paraffin was similar at different inlet temperatures of water,except for the region near to the phase interface.The interface moved faster at a lower inlet temperature of water.The moving rate of the interface slowed down at first,and became faster again when the interface was discontinuous.The results can provide the guidance for choosing the right inlet temperature of water for an appropriate solidification rate of paraffin.

Key words:

蛇形盘管, 进口温度, 传热过程, 石蜡, 凝固