折流板结构对管壳式换热器壳程流动与传热的影响

利用F luent软件,对弓形折流板换热器和连续螺旋折流板换热器壳程的流场、流动阻力和换热进行了数值模拟分析,并对计算结果进行了实验验证.结果表明,弓形折流板换热器壳程存在明显的流动滞流区,螺旋折流板换热器中的流场分布则比较均匀.在相同的流量条件下,螺旋折流板换热器壳程的流动压降大约只有弓形折流板换热器的32%,换热能力则略低于弓形折流板换热器,但单位压降下的换热系数有很大的提高,大约是弓形折流板换热器的1.3倍.数值计算结果与实验值符合良好,说明采用的数学模型是合理的,较真实地反映了换热器的实际情况.

The influence of baffle structure on shell side fluid flow and heat transfer for shell-and-tube heat exchanger

Velocity fields,flow resistance and heat transfer in shell side of shell-and-tube heat exchanger with the segmental baffles and the continuous helical baffle were simulated using Fluent software.An experiment was performed to validate the calculated results.The results show that there are obvious stagnation region in the segmental-baffle heat exchanger and uniform velocity fields in continuous-helical-baffle heat exchanger.At the same flow rate,the pressure drop in the continuous-helical-baffle heat exchanger is about 32% of that of segmental-baffle heat exchanger,but the heat transfer rate is slightly lower.The heat transfer coefficient of continuous-helical-baffle heat exchanger under the identical pressure drop is larger than that of segmental-baffle heat exchanger,about 1.3 times.The calculated values are well agreed with experimental results.This implies that the mathematical models used in this paper are reasonable and the actual condition of heat exchanger is well simulated.