How to prevent tube bundle corrosion in the crude oil constant-pressure/constant-temperature heat exchanger of petroleum refining units?
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The image below shows the heat exchanger tube bank of the atmospheric and vacuum distillation unit in the petrochemical industry, for crude oil processing. Operating conditions: Tubing route: single line, temperature 128°C, pressure 2.11 MPa. Shell side: Medium, crude oil; temperature 94°C, pressure 2.03 MPa. After the tube bundle cleaning, it can be seen that the corrosion is quite severe.
To prevent corrosion of the heat exchanger tubes in petrochemical plants, the following measures can be taken: 1. Select corrosion-resistant materials: Based on the chemical composition of the crude oil and the operating conditions, choose tube materials that are better suited to withstanding high temperatures and corrosion, such as stainless steel, duplex steel, or nickel-based alloys. 2. Add an anti-corrosion coating: Apply a corrosion-resistant protective layer, such as epoxy resin, to the heat exchanger tube bundle to prevent direct contact between the tubes and corrosive substances. 3. Optimize operating conditions: Adjust temperature and pressure to minimize severe corrosion of metal materials by acidic substances present in the medium at high temperatures. 4. Regular inspection and cleaning: Periodically inspect and clean the tube bundle to detect and address corrosion issues promptly, preventing the spread of corrosion. 5. Use corrosion inhibitors: Add an appropriate amount of corrosion inhibitors to crude oil to slow down the rate of corrosion. Through the above methods, the corrosion problem of the tube bundle in conventional heat exchangers can be effectively reduced or avoided. .
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