燃油加热炉熔灰腐蚀研究进展

高温熔盐腐蚀研究近几十年来取得重要进展,先后发展了盐溶腐蚀模型、电化学腐蚀模型等。盐溶腐蚀模型的基本观点是熔盐与金属的反应,使得在氧化物/熔盐交界面处的熔盐的碱度增高或降低,导致保护性氧化物层发生碱性或酸性溶解;电化学模型认为熔盐腐蚀的本质是电化学腐蚀;这些模型为燃油加热炉熔灰腐蚀研究提供了理论依据。燃油加热炉熔灰腐蚀和燃料油中含有的镍、钒和硫等杂质、炉膛温度、气氛中氧、二氧化硫分压及金属合金元素组成等因素有关。熔灰腐蚀控制主要采用化学添加剂、燃料油脱硫脱金属、控制过剩空气系数以及采用防护涂层等措施。文章对以往研究成果进行了总结,并介绍了未来的研究方向。

Research Progress on the Corrosion of Fused Ash in Fuel-fired Furnace

The past several years have found great development in the research on the corrosion of high temperature fused sails. The salt fusion corrosion model and electro - chemical corrosion model have been developed. The salt fusion model is established on the following basis : The reaction of fused salt with the metal increases or reduces the alkalinity of the fused salt at the interface of oxides and fused salt, which leads to the alkaline or acid dissolution of the protective oxides; It is assumed in the electro - chemical model that the fused salt corrosion is the electro - chemical corrosion. The establishment of these models have provided a theoretical basis for the research on the corrosion of fused ash in oil - fired furnace. The corrosion of the fused ash in oil - fired furnace is closely related to the impurities in the fuel such as Ni , V and S as well as the furnace chamber temperature, the partial pressure of oxygen and sulfur trioxides and composition of the alloy steel etc. The corrosion of fused ash can be controlled mainly by addition of chemicals, desulfurization and demetalization of the fuel oil, control of the excessive air and application of corrosion - resistant coating. The research work has been summarized and future research activities have been proposed.