Working principle of aluminum plate-fin heat exchanger

May 29, 20202 min read

From the perspective of heat transfer mechanism, the plate-fin heat exchanger is still a shoulder-arm heat exchanger. Its main feature is that it has an extended secondary heat transfer surface (fin), so the heat transfer process is not only performed on the primary heat transfer surface (baffle), but also on the secondary heat transfer surface. In addition to the heat of the medium on the high temperature side being poured into the medium on the low temperature side, part of the heat is also transferred along the height of the fin surface, that is, along the height of the fin, there is a partition to pour the heat, and then convectively transfer this heat to the low temperature side medium. Since the height of the fin greatly exceeds the thickness of the fin, the heat conduction process along the height of the fin is similar to the heat conduction of a homogeneous elongated guide rod. At this time, the thermal resistance of the fin cannot be ignored. The temperature at both ends of the fin is at most equal to the temperature of the partition. With the convection and heat release of the fin and the medium, the temperature continues to decrease until the temperature of the medium in the middle of the fin.ut our essential design features.

Aluminum plate-fin heat exchanger—Characteristics of aluminum plate-fin heat exchanger

High heat transfer efficiency: Due to the unique structure of the fin, it can cause disturbance to the medium, so that the thermal boundary layer is constantly broken and updated, and the convective heat release coefficient of the fluid is enhanced.

Compact structure and light weight: The heat transfer area per unit volume of aluminum plate-fin heat exchangers is generally 1500-2500m2/m3, which is equivalent to 8-20 times that of shell-and-tube heat exchangers. The weight is only one tenth of the shell-and-tube heat exchanger with the same heat exchange area, and the metal consumption per unit heat transfer area can be dozens of times smaller than that of the shell-and-tube heat exchanger.

Wide application range: It can be applied to the heat exchange of various different media between gas-gas, gas-liquid, liquid-liquid, and can also be adapted to counter-flow, cross-flow, multi-stream, multi-process through the arrangement and combination of various flow channels Wait for heat transfer under different working conditions. In the same plate-fin heat exchanger, as many as 13 streams can exchange heat at the same time, and can be extracted from different temperature points according to the needs of the process. The applicable temperature range is -270℃~+200℃. Because the aluminum plate-fin heat exchanger uses brazing technology to braze the fins and the baffle tightly together, it bears high pressure, and some large plate-fin heat exchangers The heat exchanger can reach 8MPa.