The difference between the shell and plate heat exchanger

Comparison of shell and plate heat exchanger
Case: shell and tube heat exchanger is the chemical production used as a heat exchanger widely, heat exchanger is a new type of heat exchanger, it has the advantages of compact structure, heat transfer area per unit volume provided, heat transfer coefficient, increase or decrease in the heat transfer area can be adjusted by maintenance and cleaning. It is convenient to use, expanding the scope of. It is simple to compare the shell and tube heat exchanger and plate heat exchanger in the structure and performance of different.
Performance characteristics
Heat transfer performance
Plate heat exchanger has high heat transfer coefficient, generally up to 12560 ~ 20934KJ / m2? H. In general, the total heat transfer coefficient of plate heat exchanger is 3 ~ ~ more than that of the shell and tube heat exchanger, and the heat exchanger surface is in the same heat transfer area
The volume ratio of shell and tube heat exchanger is 5 times as large, small pressure drop; the minimum temperature difference of heat transfer: tubular heat exchanger is 3 to 5 DEG l to 3 DEG C for heat exchanger.
Area and weight
The plate heat exchanger is compact in structure, and the heat transfer area per unit volume is 2 ~ 5 times of the shell and tube heat exchanger. Compactness: shell and tube heat exchanger is 78m2/m3, plate heat exchanger is 220m2/m3. Therefore, when the same heat transfer is realized, the area of the plate heat exchanger is about 1 / 5 ~ 1 of the shell and tube heat exchanger. The plate thickness of the plate heat exchanger is 0.6 ~ 0.8mm, the heat exchange tube thickness of the shell and tube heat exchanger is from 2 to 2.5 mm, and the shell of the shell and tube heat exchanger is much heavier than that of the plate heat exchanger. In the case of the same heat exchange, the heat exchange area of the plate heat exchanger is smaller than that of the shell and tube heat exchanger, which is about 1 / 5 of the shell and tube heat exchanger. The shell plate is composed of a plurality of plate heat exchanger, can partition or rib plate is arranged in the shell of the heat exchanger to form a honeycomb structure, stranded shell plate without very thick plate heat exchanger average weight and volume only of shell and tube heat exchanger is 25% ~ 40%.
Allowable stress and temperature
The shell and tube heat exchanger can be used for high pressure and temperature. Due to the rigid connection between the tube plate and the shell, the expansion joint which can reduce the deformation of the shell and the tube bundle is not considered to be improved at higher temperature. Plate heat exchanger is a cushion, so the plate plate pressure and temperature depends on the elastic gasket. The maximum allowable pressure is 2.5 MPA, and the temperature is below the temperature of 250 C.
Fouling factor
Due to the intense turbulent heat exchanger plate asked fluid dynamic, impurity deposition is not easy and stainless steel surface smooth, easy to clean, so the fouling coefficient of plate heat exchanger fouling coefficient ratio of shell and tube heat exchanger is much smaller.
heat loss
Plate heat exchanger is only exposed in the atmosphere around the plate, the heat loss is only about 1% of the total heat transfer.
conclusion
Plate heat exchanger is a kind of high efficiency compact heat exchanger. Due to high heat transfer coefficient, small pressure loss, compact structure, convenient maintenance and other technical advantages, and with the improvement of the structure and the large scale manufacturing improvement has been more widely used; in addition to high temperature and high pressure and special medium conditions, using plate heat exchanger instead of shell and tube heat exchanger can be achieved obvious effect. But the bulk of the plate heat exchangers (detachable heat exchanger) because of their structural limitations, the use of pressure is less than 2.5 MPA, the use of temperature does not exceed 250 degrees, there is also a fluid and sealing gasket compatibility issues. Plate heat exchangers are widely used in petroleum, chemical, metallurgical, refrigeration, HVAC and environmental protection industries