Non-Newtonian fluids play a key role in chemistry,food,materials,and other fields.They usually have low heat transfer performance due to the high apparent viscosity.The blade-type static mixers have distinctive technical characteristics in chemical process intensification as a kind of efficient heat transfer enhanced equipment.The flow and heat transfer characteristics of non-Newtonian fluids in Kenics(KSM)and Lightnin static mixers(LSM)were compared.The effects of volume flow rate,aspect ratio and solution concentration on the flow and heat transfer of carboxy-methyl cellulose(CMC)power-law fluids were analyzed.The results showed that the higher volume flow rate of CMC solution contributed to the higher heat transfer coefficient and pressure drop.The static mixing elements significantly enhanced the heat transfer coefficient and pressure drop,and the influence of Lightnin was more obvious.The aspect ratio of the elements and the concentration of the CMC solution also affected the fluid flow and heat transfer.The heat transfer performance was improved with the decreasing aspect ratio,while the comprehensive heat transfer performance coefficient(PEC)decreased because the influence of increased friction coefficient was dominated.The increase of solution concentration gradually weakened the heat transfer capacity and significantly increased the pressure drop thus the comprehensive heat transfer performance decreased.It was concluded that the KSM with aspect ratio of 3.0 had the highest PEC which was 2.114 when the volume flow rate was 4.5×10-4m3/s and the solution concentration was 0.374%.
关键词
非牛顿流体/静态混合器/传热/综合换热性能系数/数值模拟
Key words
non-Newtonian fluids/static mixer/heat transfer/comprehensive heat transfer performance coefficient/numerical simulation
维普
万方数据