Before selection, the medium name, concentration, and temperature range must be clarified to verify plate material and flow channel compatibility. For example, cooling water and ethylene glycol solution have different material requirements.
Provide the medium name, concentration, inlet temperature, outlet temperature, and flow rate. Concentration affects corrosiveness, and the temperature range determines the gasket material.
Confirm the system design pressure and allowable pressure drop. Welded plate heat exchangers have narrow flow channels, so the medium flow velocity and pressure drop within the channels must be calculated to avoid local overheating or excessive power consumption.
Calculate the required plate area based on the heat transfer rate, and allow a 10%~20% margin. During hydraulic station commissioning, if the return oil temperature rises from 45℃ to 62℃ within half an hour and the cooling water valve is fully open but still cannot cool it down, it indicates insufficient heat exchange area or blocked flow channels.
Check the connection diameter, orientation, and space dimensions. In the cooling circuit of a chemical reactor, when the temperature changes periodically, the flow velocity in the plate channels must be rechecked to prevent thermal stress fatigue.
304/316L stainless steel is commonly used. For media containing chloride ions, titanium or high-molybdenum stainless steel should be selected. Gaskets are selected as nitrile, EPDM, or fluororubber according to temperature.
