Shandong Zhilin Environmental Protection Technology Co., Ltd.

Some knowledge points about plate heat exchangers, told to you by a plate heat exchanger manufacturer in Jinan

Release time:

2022-05-15 12:00

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Jinan plate heat exchanger manufacturers believe that plate heat exchangers have a high heat transfer coefficient, generally 3 to 5 times that of shell and tube heat exchangers. The main reason is that when the fluid flows in the shell side of the shell and tube heat exchanger, there are bypasses between the baffle-shell side, the baffle-heat transfer tube, and the tube bundle-shell side. The fluid passing through these bypasses does not fully participate in heat exchange. However, plate heat exchangers do not have bypasses, and the corrugations of the plates can cause the fluid to become turbulent at low flow rates, resulting in a significant turbulent effect and thus a higher heat transfer coefficient.

Jinan plate heat exchangerManufacturer believesPlate heat exchangers have a high heat transfer coefficient, generally that of shell and tube heat exchangers3~5 times higher. The main reason is that when the fluid flows in the shell side of the shell and tube heat exchanger, there are bypasses between the baffle-shell side, baffle-heat transfer tube and tube bundle-shell side. The fluid passing through these bypasses does not fully participate in heat exchange. However, the plate heat exchanger has no bypass, and the corrugations of the plate can cause the fluid to generate turbulence at low flow rates, with a significant turbulence effect, thus obtaining a higher heat transfer coefficient.

Jinan plate heat exchanger

　　Jinan plate heat exchangerManufacturer believesThe two fluids of the plate heat exchanger can achieve pure countercurrent flow, generally using co-current or counter-current flow. However, in shell and tube heat exchangers, the two fluids flow in the shell and tube respectively. In general, it is a cross-flow mode. The logarithmic mean temperature difference is reduced. The plate heat exchanger can achieve temperature crossover, and the terminal temperature difference can reach1; shell and tube heat exchangers cannot achieve temperature crossover (i.e., the secondary side outlet temperature cannot be higher than the primary side outlet temperature), and the terminal temperature difference can only reach 5.

　　Jinan plate heat exchangerManufacturer believesNTU represents the heat transfer capacity of a heat exchanger relative to the fluid heat capacity and flow rate. For example, for a given heat transfer coefficient K and heat capacity GCp, the size of NTU means the size of the heat exchanger, i.e., the size of the heat transfer area. The NTU of a shell and tube heat exchanger is about 0.2~0.3 (average 0.25). The NTU of a plate heat exchanger is about 1.0~3.0 (average 2.0).

　　Due to the plate heat exchanger'slarger NTU, under the same heat exchange capacity, the size of the heat exchanger required is also smaller. In addition, the plate heat exchanger has a compact structure, and the heat transfer area per unit volume is 2~5 times that of the shell and tube heat exchanger. The shell and tube heat exchanger does not need to reserve a repair site for extracting the tube bundle, so the floor area of the plate heat exchanger is 1/5~1/10 that of the shell and tube heat exchanger.

　　Jinan plate heat exchangerManufacturer believesThe plate thickness of the plate heat exchanger is only0.6~0.8mm, and the heat transfer tube thickness of the shell and tube heat exchanger is 2.0~2.5mm. The shell of the shell and tube heat exchanger is much heavier than the frame of the plate heat exchanger. Therefore, under the same heat exchange capacity, the heat exchange area of the plate heat exchanger is smaller than that of the shell and tube heat exchanger, and its weight is about 1/5 that of the shell and tube heat exchanger.

　　Jinan plate heat exchangerManufacturer believesThe detachable plate heat exchanger is sealed by gaskets, and the sealing perimeter is long. Moreover, the two sealing supports of the corner holes are poor, and the gasket cannot get enough clamping force, and the working pressure is only2.5MPa. Brazed and fully welded plate heat exchangers change the sealing form of detachable plate heat exchangers, and plate-shell heat exchangers change the inlet (outlet) form of the two fluids, increasing the working pressure of the plate heat exchanger. Currently, the working pressure of brazed and fully welded plate heat exchangers is 3.5~4MPa, and the working pressure of plate-shell heat exchangers is 8MPa. In detachable heat exchangers, corrugated channels are formed by strengthening conventional corrugated plates, which can both enhance heat transfer and increase the pressure-bearing capacity of plate heat exchangers.

What are the characteristics of plate heat exchangers? A Jinan plate heat exchanger manufacturer explains.

Plate heat exchanger advantages shared by manufacturers