Issues with the inlet and outlet of plate heat exchangers?
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Guys, I have a few questions regarding plate heat exchangers: 1. Does the cold fluid also flow in from below and out from above, while the hot fluid generally flows in from above and out from below? 2. Plate heat exchangers have two inlets and two outlets; for the same type of fluid, are the inlet and outlet on the same side, such as the left side, while on the other side, the inlet and outlet for the other type of fluid are located at the top and bottom respectively? Why are, in some heat exchangers, the inlet and outlet for the same fluid located on the left and right sides respectively?
In my opinion, when determining the inlet methods for the hot and cold fluids in plate heat exchangers, the counterflow principle should be the main consideration; therefore, there is no requirement that the cold fluid must enter from below and exit from above. The second question: In conventional plate heat exchangers, the flow of the medium is always in the same direction (at least in our company we have never seen any case where the flow enters and exits in opposite directions). The staggered flow pattern you mentioned might be due to other engineering considerations (but I think that would require the plates to be specially manufactured, which doesn’t seem reasonable)
The flow direction of the heat exchanger cannot be determined solely by direction; it must be based on the diagrams provided in the heat exchanger’s manual. For reference.
The positioning of the inlet and outlet ports in a plate heat exchanger is mainly related to the stamping process of the plates
1. There are no requirements regarding the direction of heat flow; generally, counterflow heat exchange is preferred as it results in a higher logarithmic mean temperature difference and thus requires less heat exchange area. 2. It is determined by the internal structure, with manufacturing being carried out with the goal of achieving a high heat exchange coefficient for the equipment
The inlet and outlet ports of the hot and cold media that are visible from the outside are determined by the actual flow path of the media inside; different manufacturers may use different designs! Take a look at the structure diagram in the manual
This can be done in parallel or in series, depending on the goal to be achieved