How to increase heat transfer coefficient in plate heat exchanger?
The low heat transfer coefficient of the plate heat exchanger will affect the heat transfer efficiency of the plate heat exchanger, thereby reducing the production efficiency of the enterprise. Therefore, how to improve the heat transfer coefficient of the plate heat exchanger is a problem that people want to know.
(1)Improve the heat transfer coefficient of the plate surface
We all know that the plate corrugations of the plate heat exchanger can cause the heat exchange medium to generate turbulence at a small flow rate, thereby obtaining a high surface heat transfer coefficient. Therefore, the surface heat transfer coefficient of the sheet is related to the geometry of the sheet corrugations and the flow state of the heat exchange medium. The more common plate corrugations include herringbone, straight, spherical.. Generally speaking, the surface heat transfer coefficient is high, and the angle of the corrugation is larger. The higher the medium flow velocity in the flow channel between the plates, the larger the surface coefficient.
(2)Reduce the thermal resistance of the dirt layer
The key to reducing the thermal resistance of the fouling layer is to prevent plate fouling. When the sheet fouling thickness is 1 mm, the heat transfer coefficient is reduced by about 10%. Therefore, it is very important to detect the heat exchange medium of the plate heat exchanger to prevent the inclusion of impurities in the medium on the plate to form scale. If there is viscous impurities in the media, use a special filter for disposal.
(3)Use a plate with high thermal conductivity
Stainless steel has good thermal conductivity, high strength, good stamping performance, and is not easily oxidized, but its ability to resist chloride ion corrosion is poor. Therefore, different materials can be selected according to different working conditions. Generally, austenitic stainless steel and titanium materials are used. It is a commonly used sheet material.
(4) Reduce the thickness of the plate
The thickness of the plate heat exchanger plate has nothing to do with corrosion resistance, and it is related to the pressure bearing capacity and heat transfer coefficient, and the plate is thickened, which can improve the pressure bearing capacity of the heat exchanger. When the herringbone plate is used, the adjacent plates are inverted and the corrugations are in contact with each other, forming a dense and uniform distribution finger. The plate corner and edge sealing structure have been gradually improved, so that the heat exchanger has a good pressure. ability. Under the premise of satisfying the pressure bearing capacity of the heat exchanger, the thickness of the plate should be selected as much as possible.