Wall heat exchange is the heat exchange of fluids on both sides of the partition wall. Cold and hot fluids are separated by solid wall surfaces, and they flow on both sides of the wall surface.There are many types of partition wall heat exchangers, they are all typical heat transfer equipment.Generally, the heat transfer between a fluid and a solid wall is called a convective heat transfer process. The heat transfer between hot and cold fluids through walls is called a heat exchange process. Partition wall heat exchanger with plate as heat transfer surface. This type of heat exchanger has a compact structure and a large heat transfer area per unit volume. What are the main types of plate heat exchangers?
(1) The spiral plate heat exchanger is formed by rolling two parallel metal plates with a distance between them. Cold and hot fluids flow in spiral channels on both sides of the metal plate.The heat transfer coefficient of this heat exchanger is 2-4 times higher than that of the shell and tube heat exchanger, the average temperature difference is large, the flow resistance is small, and it is not easy to scale; but it is difficult to maintain. Its working pressure is not more than 2MPa.
(2) The flat plate heat exchanger is composed of corrugated thin plates and sealing gaskets alternately superposed and clamped and assembled with a frame. Cold and hot fluids flow through the flow channels on both sides of the corrugated plate, and heat is exchanged through the plate. The corrugated plate is usually punched from stainless steel, aluminum, titanium, molybdenum and other thin plates with a thickness of 0.5 to 3 mm.
(3) The plate-fin heat exchanger is composed of a heat exchange plate bundle enclosed in a header with cold and hot fluid inlets and outlets.The plate bundle is formed by overlapping the flat plate and the corrugated fins alternately and brazing and fixing.Cold and hot fluids flow through both sides of the plate to exchange heat. The fins not only increase the heat transfer area, but also promote the turbulence of the fluid and increase the equipment. The plate-fin heat exchanger has a compact structure, good heat transfer, and an operating pressure of up to 15 MPa. But its manufacturing process is complicated, the flow channel is small, and the internal leakage is not easy to trim.