During on-site inspections, if maintenance personnel find rust spots or coating peeling on the fin surface, they should take samples for analysis in a timely manner to determine whether the material needs to be replaced or additional protective measures are required. Compared with handling issues only after a failure occurs, recording changes in fin appearance on a periodic basis can identify trends of dust accumulation and corrosion in advance, avoiding insufficient heat transfer area due to increased fouling thermal resistance.
If any parameter such as air volume, medium temperature, or fin spacing is missing during the design and selection stage, the deviation between calculation results and actual operation may exceed the allowable range, resulting in insufficient heat transfer area or excessive pressure drop. In contrast to directly applying general catalog data, on-site maintenance personnel should verify the technical parameters confirmed according to project data during the contract stage, and should not directly use catalog values as the basis for operation.
1. Check the fin surface for rust spots, coating blistering, or dust accumulation every shift; 2. Record the inlet and outlet pressure difference monthly, and arrange purging when the pressure difference continues to rise; 3. Check quarterly for looseness or corrosion thinning at the connection between fins and tube bundles; 4. During shutdown, take samples from the fin surface for analysis, and decide based on the analysis results whether to replace the material or add coating protection.
Control water pressure and angle during purging to avoid fin deformation; before replacing materials or adding protective measures, evaluate in combination with medium composition and operating temperature, and it is not recommended to apply coatings directly without sampling and analysis. If pressure drop or heat transfer rate deviates from the design value during operation, first check fin cleanliness and air volume distribution, then determine whether the tube bundle needs adjustment.
