钛纳米涂层换热器管束在大型冷换设备中的应用

Application of titanium nanocoated heat exchanger tube bundlesin large-scale cold exchange equipment

针对石油化工装置中的特大型水冷器与冷凝器的设备防腐,目前主要是采用热固化涂料对换热器管束进行防腐涂装。经过实践证明,防腐蚀涂层通常使用2~3 a便会出现失效问题,其使用寿命达不到设计要求。某0.6 Mt/a甲醇深加工装置丙烯制冷剂冷凝器循环水侧管束的防腐蚀涂层已使用3 a,重点对该管束涂层的失效原因进行分析,认为其失效原因主要有两个,一是涂层材料与涂装的问题;二是涂层表面存在水垢层,造成垢下腐蚀,使换热管热阻增加,冷凝效果下降。根据换热器管束防腐涂层存在的问题,设计了一种节能防腐钛纳米涂层管束。此钛纳米涂料可常温固化,有利于现场涂装施工。管束经涂装后可以连续安全使用10 a以上,在换热器管束防腐蚀技术中,钛纳米涂层是目前综合效益最好的一种。

Thermosetting coating is widely used in heat exchanger tube bundle of large-sized water cooler and condenser in petrochemical plant.Practice proved that the coating usually fails after 2-3 years,and the service life can not meet design requirements.Analysis was studied on the failed anti-corrosion coating of circulating water side tube bundle in propylene refrigerant condenser of a 0.6 Mt/a methanol deep processing unit.It is believed that there are two main reasons for the failure.Firstly,there are issues with coating material and coating treatment.Secondly,there is a scale layer on the surface of coating,which causes corrosion under the scale,thus increases the thermal resistance of heat exchange tube and reduces condensation effect.An energy-saving and corrosion-resistant titanium nanocoated tube bundle was designed to cope with the existing problems.It can be cured at room temperature and convenient for on-site construction.After coating,the tube bundle can be used safely for more than 10 years.Titanium nanocoating is currently the most competitive one among the anti-corrosion technologies for heat exchanger tube bundles.