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1, plate heat exchanger flow patterns are countercurrent, downstream and mixed flow pattern.
Under the same operating conditions, the logarithmic mean temperature difference is the largest in the countercurrent flow, and the flow rate is the smallest, and the mixed flow pattern is between the two.
The method of increasing the logarithmic mean temperature difference of the heat exchanger is to use the mixed flow pattern of countercurrent or countercurrent as far as possible, to increase the temperature of the hot side fluid as much as possible and to reduce the temperature of the cold side fluid.
2, for a single process layout of the plate heat exchanger, for easy maintenance, fluid inlet and outlet pipe should be arranged as far as possible in the heat exchanger fixed end plate side.
The greater the temperature difference of the medium, the stronger the natural convection of the fluid, the more obvious the effect of the retention zone.
So the media inlet and outlet position should be carried out by the hot fluid into the cold fluid into the out of the layout, in order to reduce the impact of the retention zone, improve heat transfer efficiency.