管壳式换热器在线清洗的机理分析与数值模拟

Analysis and Numerical Simulation of On-Line Cleaning for Heat Exchanger with Baffle Plate

管壳式换热器在在线化学清洗的过程中,由于循环泵提供的扬程(功率)不足,使清洗剂在壳程中无法达到应有的流速,从而导致溶解的污垢由于自重或黏性依附于换热设备底部,无法随清洗剂带出的现象,严重影响了换热设备在线化学清洗的效果,阻碍了这项新技术的推广与应用,达不到企业节能减排的目标。本文基于换热设备在线化学清洗时流体机械作用最小阈值概念及埃索计算公式,对在线化学清洗过程中壳程流体的机械冲力进行了计算与分析,并利用FLUENT进行数值模拟分析,得出了在线化学清洗中循环泵等设备重要参数的确定原则,对企业技术人员应用这项新技术提供了参考。

In the process of on-line chemical cleaning in the heat exchanger with baffle plate, the fouling can not be brought with the cycle of detergent because the lift provided by pump is not enough. The speed of detergent is too low to take away the fouling. Most fouling deposited on the bottom of the heart exchanger. The phenomenon has a serious impact on the result of cleaning and hampered the popularization and application of online cleaning. The enterprises could not reach the target on energy saving and emission reducing. When doing cleaning, there is a minimum number to judge whether the mechanical action is useful. Base on this, the minimum number of pressure provided by pump can be calculated by the Esso formula and so on. The numerical simulation analysis has also been done by FLUENT. The calculated result can be accepted compared with the actual result. It provides technical personnel a good reference when designing the process of on-line clean ing.