a. High heat transfer coefficient;
Since different corrugated plates are inverted each other to form a complex flow channel, the fluid flows in a three-dimensional rotation in the flow channel between the corrugated plates, which can produce turbulent flow at a low Reynolds number (generally Re=50~200), so heat transfer The coefficient is high, generally considered to be 3 to 5 times that of the shell and tube type.
b. The logarithmic average temperature difference is large, and the terminal temperature difference is small.
In the shell-and-tube heat exchanger, the two fluids flow in the tube side and the shell side respectively, and the flow is generally cross-flow, and the logarithmic average temperature difference correction coefficient is small, while the plate heat exchanger mostly uses co-current or counter-current flow. , The correction coefficient is usually about 0.95. In addition, the flow of cold and hot fluids in the plate heat exchanger is parallel to the heat exchange surface without bypass flow, so the temperature difference at the end of the plate heat exchanger is small, and the water heat can be exchanged. Below 1℃, while the shell-and-tube heat exchanger is generally 5℃fff.
c. Small footprint.
The plate heat exchanger has a compact structure, and the heat exchange area per unit volume is 2 to 5 times that of the shell and tube type. Unlike the shell and tube type, there is no need to reserve a maintenance place to extract the tube bundle, so the same heat exchange is achieved. The heat exchanger covers an area of about 1/5~1/8 of the shell-and-tube heat exchanger.
d. Easy to change the heat exchange area or process combination;
As long as you add or reduce a few plates, you can achieve the purpose of increasing or reducing the heat exchange area; changing the plate arrangement or replacing several plates can achieve the required process combination and adapt to new heat exchange conditions. The heat transfer area of the shell heat exchanger is almost impossible to increase.
e. Light weight;
The plate thickness of the plate heat exchanger is only 0.4~0.8mm, while the thickness of the heat exchange tube of the shell and tube heat exchanger is 2.0~2.5mm. The shell and tube shell is much heavier than the frame of the plate heat exchanger. , The plate heat exchanger is generally only about 1/5 of the weight of the shell and tube type.
f. Low price;
Using the same material, under the same heat exchange area, the price of the plate heat exchanger is about 40% to 60% lower than that of the shell and tube type.
g. Easy to make;
The heat transfer plate of the plate heat exchanger is processed by stamping, which has a high degree of standardization and can be mass produced. The shell and tube heat exchanger is generally made by hand.
h. Easy to clean;
Frame type plate heat exchangers can loosen the plate bundle and remove the plates for mechanical cleaning as long as the compression bolts are loosened. This is very convenient for the heat exchange process that requires frequent cleaning of the equipment.
