During on-site operation and maintenance, localized temperature anomalies in the core of plate-fin heat exchangers and gradually increasing pressure drops are commonly encountered. Upon inspection, fouling or medium residue is often found in the fin channels. The following key points are provided for daily inspection and maintenance reference.
Record the inlet and outlet pressure differential and temperature every shift. Consider cleaning when the pressure differential rises by 15% compared to the initial value. Check flange connections for leakage and verify the integrity of the insulation layer. For corrosive media, periodically measure wall thickness, paying attention to welds and fin roots.
When purchasing or replacing the core, the material must be verified against the actual medium: aluminum alloy is suitable for general operating conditions, while stainless steel is suitable for slightly more corrosive environments. When medium concentration and temperature vary significantly, it is recommended to use clad plates or apply surface treatment. Cores of different materials must not be mixed arbitrarily on site.
Use neutral cleaning agents during cleaning and avoid directing high-pressure water jets at the fins. Pay attention to the position of the gasket when disassembling and reassembling the core, and tighten the bolts in a diagonal sequence after reassembly. If fin deformation or severe blockage is found, contact professional personnel to assess whether the core should be replaced.
When the pressure drop rises abnormally, first check the filter and pipeline valves, then investigate core blockage. A narrowing temperature difference may be caused by scaling or changes in medium flow rate, and should be judged comprehensively based on operating data. It is prohibited to disassemble connectors while under pressure.
