A plate-type heat exchanger that uses a plate to form a heat transfer surface. This kind of heat exchanger has a compact structure and a large heat transfer area per unit volume. Its main types are:
It is made of two parallel metal plates kept at a certain distance, and the cold and hot fluids flow in the spiral channels on both sides of the metal plate.
This heat exchanger has a high heat transfer coefficient (approximately 1 to 4 times higher than a shell-and-tube heat exchanger) and a large average temperature difference (due to cold and hot fluids can be used for full countercurrent flow). dirt.
However, maintenance is difficult. Use pressure not exceeding 2MPa. Plate heat exchanger
2 plate heat exchanger
By a certain shape of the corrugated sheet and the sealing gasket are alternately stacked and assembled with the frame clamping.
The cold and hot fluids flow through the flow channels on both sides of the corrugated plate, respectively, and undergo heat exchange via the plates.
The corrugated plate is usually punched from a sheet of stainless steel, aluminum, titanium, molybdenum, etc. with a thickness of 0.5 to 3 mm.
The advantage of the plate heat exchanger is that the heat transfer coefficient is high (about 2 to 4 times higher than the shell-and-tube heat exchanger), and it is easy to take apart and wash, and the number of plates can be increased or decreased to adjust the heat transfer area.
The operating pressure usually does not exceed 2 MPa and the operating temperature does not exceed 250°C. Plate heat exchanger
It consists of a bundle of heat exchanger plates enclosed in a collecting tank with cold and hot fluid inlet and outlet.
The plate bundles are alternately laminated by flat plates and corrugated fins and brazed and fixed.
Cold and hot fluids flow through both sides of the plate. The fins increase the heat transfer area, promote fluid turbulence, and enhance the equipment.
The plate-fin heat exchanger structure is very compact (heat transfer area of ??4400m2/m3), heat transfer effect is good, and the use of pressure up to 15MPa.
However, its manufacturing process is complex, the flow path is small, and the inner leakage is not easy to repair, so it is limited to clean non-corrosive fluids, such as heat exchangers for air separation.