The plate heat exchanger has the characteristics of high heat exchange efficiency, low heat loss, compact and lightweight structure, small footprint, wide application, and long service life. Under the same pressure loss, its heat transfer coefficient is 3-5 times higher than that of the tube heat exchanger. It occupies one third of the tube heat exchanger, and the heat recovery rate can be as high as 90%. Increasing the heat transfer coefficient of the plate heat exchanger can increase the heat transfer coefficient of the cold and hot surfaces of the plate. If you want to reduce the thermal resistance of the dirt layer, you can choose a plate with high thermal conductivity, which can reduce the thickness of the plate and improve the heat transfer coefficient of the heat exchanger.
(1) Because the corrugation of the plate heat exchanger can cause the fluid to generate turbulence at a small flow rate, a higher surface heat transfer coefficient can be obtained. The surface heat transfer coefficient is related to the geometric structure of the plate corrugation and the flow state of the medium . A chevron plate with a triangular corrugated cross-section has a higher surface heat transfer coefficient, and the greater the angle of the corrugation, the higher the flow velocity of the medium in the flow channel between the plates, and the greater the surface heat transfer coefficient.
(2) The key to reducing the thermal resistance of the fouling layer of the heat exchanger is to prevent fouling of the plates. When the fouling thickness of the plate is 0.1mm, the heat transfer coefficient is reduced by about 10%. Therefore, we must pay attention to monitoring the water quality on both sides of the heat exchanger to prevent fouling of the plates and prevent debris in the water from adhering to the plates.
(3) The plate material of the plate heat exchanger can be selected from stainless steel, titanium alloy, and copper alloy. Because stainless steel has good thermal conductivity, the thermal conductivity is about 14.4W/(m.K), and the stamping performance is good. Stainless steel is not easy to be oxidized, and its price is lower than that of titanium alloy and copper alloy. It is often used in heating engineering.