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When selecting a plate heat exchanger, the following three points should be taken into consideration: 1. Plate type selection – The type of plates or the shape of the corrugations in a plate heat exchanger should be determined based on the actual requirements of the heat exchange process. For situations with high flow rates and a low allowable pressure drop, a plate type with low resistance should be selected; conversely, a plate type with high resistance should be chosen. For media containing solid particles, suspensions, or viscous substances, wide-channel plate heat exchangers with larger channels and deeper corrugations can be selected. Based on the fluid pressure and temperature conditions, it is determined whether to choose a detachable, semi-welded, fully welded, or brazed type. When determining the plate configuration, it is not advisable to choose plates with too small a surface area, as this may result in an excessive number of plates, lower flow velocities between them, and consequently a lower heat transfer coefficient. This issue is particularly important to consider in larger heat exchangers. 2. Selection of flow paths and channels: A flow path refers to a set of channels within a plate heat exchanger in which the fluid flows in the same direction, while a channel is the flow path for the fluid formed by adjacent plates within a plate heat exchanger. Generally, several flow channels are connected in parallel or series to form various combinations of cold and hot medium paths. Plate heat exchangers come in a variety of configuration combinations. Based on the number of passes, it can be divided into single-pass and multi-pass; based on the flow direction, it can be divided into counter-current and co-current. The process combination should be determined based on heat transfer and fluid resistance calculations, while meeting the requirements of the process conditions. Strive to make the convective heat transfer coefficients in the cold and hot fluid channels equal or similar, thereby achieving the best heat transfer performance. Although the flow velocities between the plates of a plate heat exchanger vary, the average flow velocity is still used in heat transfer and fluid resistance calculations. 3. Pressure drop verification: In the design and selection of plate heat exchangers, certain requirements are generally imposed on the pressure drop; therefore, it is necessary to conduct a verification. If the verified pressure drop exceeds the allowable value, redesign and reselection calculations must be carried out until the process requirements are satisfied. Proper selection of plate heat exchangers can not only **improve heat exchange efficiency but also reduce a company’s investment costs.