The media that plate-fin heat exchangers can handle include hydraulic oil, compressed air, and water-glycol solution. Before overhauling or replacing the core, on-site O&M personnel should first verify the correspondence between the medium type and the materials of the fins, partition plates, and seals. Under hydraulic oil conditions, attention should be paid to the compatibility between seals and the aluminum core; when compressed air contains water, it should be confirmed whether there is a risk of channel blockage caused by water condensation in the low-temperature section; for water-glycol solution, the concentration and pH should be tested regularly to avoid corrosion of the inner channel walls after long-term operation. When the medium composition changes, it is recommended to simultaneously re-verify material compatibility, and it is not advisable to directly put the unit into service using the original parameters.
After the equipment enters the low-load operation stage, the flow distribution of each fluid stream tends to deviate from the design condition, manifesting as outlet temperatures of some channels being too high or too low. Under stable operating conditions, O&M personnel can record the outlet temperature of each condition and compare them item by item with the design values to determine whether the flow distribution is uniform. If a deviation is found, adjustments can be made in combination with the on-site valve opening and the operating status of the pump set, and the temperature data before and after adjustment should be retained to provide a basis for subsequent optimization of operating parameters. This step does not require disassembling the core and is work that can be completed during routine inspections.
The BHX-80 model is suitable for applications requiring simultaneous heat exchange of multiple fluid streams, such as air separation pre-cooling, hydraulic oil cooling, and compressor interstage cooling. It has a large heat exchange area per unit volume, and its installation location is often relatively compact. During maintenance, the inspection access and lifting space should be confirmed in advance to avoid fin damage caused by insufficient disassembly space. The fin channels are relatively narrow, so high-pressure water guns should not be used for direct flushing during cleaning. It is recommended to select the appropriate cleaning method according to the medium type and to check the sealing status of each interface after reassembly.
Daily records of outlet temperature, flow rate, and pressure drop are the basic data for judging the trends of channel scaling and blockage. It is recommended to record key parameters by shift. When pressure drop rises or heat exchange performance declines, historical data can be traced back to determine the time period when the problem occurred, and then targeted inspection or cleaning can be arranged.
