Issues to note for plate heat exchangers

The type of plate or corrugated type should be determined according to the actual needs of the heat exchange occasion. For large flow and small allowable pressure drop, a plate type with small resistance should be selected, and vice versa. Determine whether to choose a detachable type or a brazed type according to the fluid pressure and temperature. When determining the plate type, it is not advisable to choose a plate with too small a single plate area, so as to avoid too many plates, too low flow velocity between plates, and too low heat transfer coefficient. This problem should be paid more attention to for larger heat exchangers.
The flow refers to a group of parallel flow channels in the same flow direction of a medium in a plate heat exchanger, and the flow channel refers to the medium flow channel composed of two adjacent plates in a plate heat exchanger. In general, several flow channels are connected in parallel or in series to form different combinations of cold and hot medium channels.
The combination of flows should be determined based on heat exchange and fluid resistance calculations and under the conditions of meeting process conditions. Try to make the convection heat transfer coefficients in the cold and hot water flow channels equal or close to each other to obtain the best heat transfer effect. Because the heat transfer coefficient obtains a larger value when the convection heat transfer coefficients on both sides of the heat transfer surface are equal or close. Although the flow rate between the plates of the plate heat exchanger is not equal, the average flow rate is still used for calculation of heat exchange and fluid resistance. Since the "U"-shaped single-flow pipes are fixed on the clamping plate, they are easy to disassemble and assemble.
In the design and selection of plate heat exchangers, there are generally certain requirements for pressure drop, so it should be checked. If the checked pressure drop exceeds the allowable pressure drop, the design selection calculation needs to be re-performed until the process requirements are met.