某化工企业换热器化学清洗中试研究

Pilot test on chemical cleaning of exchanger in a chemical enterprise

某化工企业循环水处理系统在冷态运行过程中循环量大幅衰减,检查发现换热器内部存在严重的腐蚀结垢问题。为使循环量尽快恢复至设计值,决定对循环水系统进行整体化学清洗。选取3台腐蚀程度接近的换热器进行化学清洗中试试验,并对清洗剂的选择及用量进行优化。结果表明:在选用柠檬酸作为清洗主剂、氨基磺酸作为pH调节剂的条件下,当清洗液中柠檬酸质量分数为2%时,换热器的清洗效果明显,其内流体流速和流量恢复至设计值,且挂片腐蚀速率满足GB/T 50050—2017要求(<0.075 mm/a)。

A chemical enterprise had a set of circulating water treatment system,and during the operation of the system without heat load,it was found that the circulation capacity of the system decreased significantly.Through the inspection,it was found that there were serious corrosion and scaling problems in the heat exchanger.In order to restore the circulation rate to the design value as soon as possible,it had been decided to carry out an overall chemical cleaning of the circulating water system.Three heat exchangers with similar corrosion degree were selected for the chemical cleaning pilot test,and the selection and dosage of cleaning agent was optimized.The results showed that when citric acid was selected as the main cleaning agent and sulfamic acid as the pH regulator,when the citric acid mass fraction in the cleaning solution was 2%,the cleaning effect of the heat exchanger was obvious,the flow rate and flow inside the fluid returned to the design value,and the corrosion rate of coupon met the GB/T 50050—2017 requirement(<0.075 mm/a).