During on-site commissioning, procurement personnel often report that different batches of welded plate heat exchangers under the same process tag number exhibit differences in heat transfer capability. Some units show elevated outlet oil temperatures in hydraulic oil cooling circuits, while others exhibit excessive pressure drop under domestic hot water conditions. After disassembly and comparison, it was found that the differences mainly stem from the consistency of plate flow channel cross-section design and welded plate process, rather than merely differences in material grades.
If orders are placed based only on connection sizes and design pressure during the procurement stage, it is easy to overlook the matching relationship between medium flow rate and allowable pressure drop. The flow channel cross-section of a welded plate heat exchanger is determined by thermal calculations and cannot be adjusted after inflation forming. When comparing products of the same specification, emphasis should be placed on verifying the heat transfer rate, pressure drop, and fouling factor allowance under rated conditions, rather than merely comparing the number of plates or external volume.
The YBJ-120 welded plate heat exchanger is suitable for hydraulic oil cooling, domestic hot water preparation, and process fluid heat recovery. During selection, four boundary conditions should be provided: medium name, inlet and outlet temperatures, flow rate, and allowable pressure drop, so that the supplier can verify the flow channel cross-section and plate combination. Before commissioning, confirm that all connection flanges are tightened without leakage and that pressure gauges and thermometers are within their valid calibration periods. For variable-condition operation, it is recommended to specify the heat transfer margin under non-rated conditions in the procurement technical agreement to facilitate later operational adjustments.
