I have a question regarding heat exchangers

If there is sufficient heat exchange margin, this is also fine; under normal circumstances, counterflow yields better results

The specific process details are unclear, but generally speaking, the temperature difference for heat transfer in a co-current flow is small; for the same heat transfer load, a larger heat exchange area is required.

Counterflow is the best; co-current flow has a poorer heat transfer effect

Got it, thanks! {:1_90:}

Got it, thanks! {:1_90:}

Thank you for the reply! {:1_90:}

(1) The effects of flow in the same direction and opposite directions; the effects of opposite-direction and cross-flow are better than those of flow in the same direction. (2) Considering the changes in density and temperature of the same medium, as the cold flow is heated its density decreases, causing it to rise within that same medium; thus, the cold flow enters from below and exits from above, preventing reverse convection within the space. On the contrary, the heat flow is condensed, its density increases, and it sinks naturally; therefore, it is advisable to allow flow from top to bottom, which also helps to prevent convection from occurring and creating flow resistance. (3) From the perspective of exhaust and condensate removal, for example with steam, it may condense during heat exchange, which facilitates the removal of condensate. After absorbing heat, the cold flow may undergo phase change to produce gas, which facilitates exhaust. If the direction is reversed, liquid resistance may occur on the steam side, while gas resistance may arise on the cold flow side. It is not conducive to heat exchange.

This is flow in the downstream direction, and the heat exchange efficiency is lower, as the temperature difference between the two sides decreases near the outlet, resulting in a reduced heat exchange efficiency

Under the same heat exchange area, counterflow heat exchange yields better results