How much higher should the inlet-outlet pressure differential be compared with the initial commissioning period before cleaning should be scheduled? This is a question frequently asked by on-site O&M personnel. For the HX-68 plate-fin heat exchanger, using pressure differential and temperature data as clues, the following key points are summarized for reference.
Record the inlet-outlet pressure differential and temperature every shift. When the pressure differential rises by 15% above the initial value, cleaning of the fin channels may be considered; if the outlet temperature continues to rise or the pressure drop increases significantly, check whether the fin surfaces have fouling and whether the fluid distribution is uniform. After cleaning, re-measure the pressure differential to confirm recovery.
During low-load operation in winter, heat transfer efficiency decreases, mostly because the medium flow rate is below the design value, causing uneven flow velocity in the channels. During O&M, the flow rate or bypass ratio can be adjusted appropriately so that the flow velocity in the channels approaches the design range, and the outlet temperature trend should be monitored.
Mismatch between nozzle orientation and existing piping is a matter that must be confirmed before ordering. Before on-site installation, the three-dimensional layout drawing should be checked to confirm that the nozzle orientation, size, and piping routing are consistent, avoiding additional pipe modification work due to orientation deviation.
During inspections, record inlet and outlet temperatures, pressure differential, and flow rate, and establish an operation trend ledger. Comparing historical data can help identify signs of fin fouling or uneven distribution in advance, providing a basis for cleaning and adjustment.
