错流型多级雾化旋转填料床传热性能的试验研究

Experimental research on heat transfer of cross-low multi-atomization rotating packed bed

采用空气冷却热水方式,对错流型旋转填料床进行传热性能试验.试验结果表明,比表面积、体积传热系数、以湿度为基准的气相体积传质系数均与雾化次数有显著关系,二次雾化比一次雾化增加21%,三次雾化比二次雾化增加18%,而与液流量无关.传热系数、以湿度为基准的气相体积传质系数不随雾化次数和液流量变化,基本上保持在0.52 kW·m-2·K-1,0.122 kg(m2·sΔH)-1.从而揭示出错流型旋转填料床强化气液传热的机理是由于将液滴雾化,极大地增加了传热面积,而不是提高了传热系数和以湿度为基准的气相体积传质系数.错流型旋转填料床经过三级雾化后,体积传热系数可达98 kW/(m3·K),结构更紧凑.

The heat transfer feature of a cross-flow multi-atomization rotating packed bed is studied by the mode of air-cooling hot water.The suction pressure of an axial gas fan is about 120 Pa,where rotating speed is about 1400r/min.The experiments show that the specific surface area per volume and the volumetric heat-transfer coefficient after two times atomization are increased 21％ than one time atomization,decreased 18％ than three times atomization,respectively.These are significantly varied with the atomization times,and they are independent of the liquid flow.The heat transfer coefficient and gas volumetric mass transfer coefficient based on humidity are not varied with the atomization times and the liquid flow change,remaining substantially 0.52 kW · m-2 · K-1 and 0.122 kg （m-2 · s A H）-1 respectively.The results reveal that the mechanism of the enhance of a gas-liquid heat transfer in the cross-flow rotating packed bed is due to the droplet atomization that greatly increases the heat transfer area,rather than the heat transfer coefficient and gas volumetric mass transfer coefficient based on humidity.After three times atomization,the volumetric heat transfer coefficient of this cross-flow rotating packed bed could reach up to 98 kW/m3 · K,keeping the bed more compact.