How to address the corrosion of the inner walls of air coolers in petrochemical applications involving low-temperature light oils and oil-gas streams?
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It was caused by corrosion and leakage in the tube bundles of the air-cooling equipment, which severely affected the safe, stable, and full-load operation of the production facility. After about 1 year of operation of the air cooler, a layer of rust easily forms on the tube bundle, increasing the thermal resistance and severely reducing the heat exchange efficiency, thereby failing to meet the requirements of production. For petrochemical companies, the amount of money spent each year on replacing air-cooled tube bundles due to corrosion accounts for a significant proportion of the total costs associated with overhauls and upgrades. In recent years, the petrochemical industry has adopted various measures to address the corrosion of the inner walls of air cooler tubes, and through years of effort, it has achieved some significant results and economic benefits. However, with the current situation, there are still some issues that have not been resolved. In particular, there is still no effective method for addressing the corrosion issue on the inner wall of the air cooler tube bundles. The corrosion in this area is a type of corrosion that occurs in low-temperature light oil and oil-gas environments; the corrosive agents involved are mainly hydrogen sulfide and water when water is present (H2S-HCN-H2O). Let’s explore whether there are any effective anti-corrosion methods to address such corrosion.
To address the corrosion issue on the inner walls of air coolers in the petrochemical industry, the following solutions can be considered: 1. Material selection: Use materials with better corrosion resistance to manufacture the tube bundles, such as stainless steel, nickel-based alloys, or materials coated with anti-corrosion layers. 2. Corrosion inhibitors: Corrosion inhibitors are added to the fluid; these inhibitors form a protective film that reduces direct contact between the pipes and corrosive substances. 3. Equipment improvement: Optimize the design of the air coolers, such as increasing the spacing between tubes and improving fluid distribution, in order to reduce corrosion caused by excessively high local flow velocities. 4. Regular maintenance: Strengthen daily monitoring and maintenance, clean the tube bundles regularly, and remove rust and deposits promptly to avoid increased corrosion risks due to long-term accumulation. 5. Environmental control: Try to remove or control harmful components in the corrosive medium such as moisture and hydrogen sulfide; for example, use dryers or gas purification systems to pre-treat the medium flowing into the air cooler. Through the above measures, the corrosion problem on the inner wall of the air cooler can be effectively alleviated, the service life of the equipment can be extended, and maintenance costs can be reduced. .
The top expert in China in this field is Gu Wangping; back over a decade ago, when he was giving lectures to us, he mentioned many solutions for the corrosion of air coolers used in oil refining. However, most of the solutions he discussed related to chloride-induced corrosion, and he had never spoken about corrosion caused by hydrogen sulfide
Chloride corrosion is influenced by these factors