When selecting a plate-fin heat exchanger, the design pressure and applicable temperature must first be verified. Common industrial models have a design pressure range of 0.6–3.0 MPa and an applicable temperature range of -40°C to 150°C. On-site operation and maintenance personnel should confirm whether the system's maximum working pressure and extreme temperatures fall within these ranges, to avoid over-limit operation causing fin deformation or seal failure. Compared with shell-and-tube heat exchangers, plate-fin structures are more compact, but their flow channels are narrower, placing higher demands on medium cleanliness. If the medium contains particulates or is prone to scaling, pre-filtration or a wide-channel solution should be used.
During selection, complete hot-side and cold-side parameters must be provided, including flow rate, inlet and outlet temperatures, allowable pressure drop, and medium physical properties. Compared with similar models, if only one side's parameters are provided, it is easy to cause insufficient heat exchange area margin or uneven fluid distribution. It is recommended to review flow distribution under low-load system conditions to confirm whether flow maldistribution occurs in each channel. Reasonable arrangement can bring the outlet temperature of each fluid stream close to the process setpoint; improper arrangement will result in one stream being overcooled or overheated. Operation and maintenance personnel can record the outlet temperature deviation of each stream during the commissioning stage as a basis for arrangement adjustment.
Detachable plate heat exchangers are easy to clean mechanically, but gaskets need regular replacement after aging, and their pressure and temperature resistance limits are usually lower than those of brazed plate-fin structures. Plate-fin heat exchangers use integral brazing, with no gasket leakage points, making them suitable for working conditions with limited space and clean media. On-site operation and maintenance should note: when pressure drop rises abnormally, first check the filter differential pressure rather than directly disassembling the core. If cleaning is truly necessary, chemical cleaning or reverse flushing should be used to avoid mechanical brushing damaging the fins.
It is recommended to check in the following order: 1. Whether the design pressure and temperature cover the on-site extreme working conditions; 2. Whether the hot-side and cold-side flow rates, temperature differences, and allowable pressure drops are complete; 3. Whether the flow distribution in each channel is uniform under low load; 4. Whether the medium cleanliness meets the requirements of narrow channels; 5. Whether the installation space and port orientation match. After completing the above checks, confirm the core arrangement plan with the supplier to reduce the risk of later outlet temperature deviation from the setpoint.
