The main types of plate heat exchangers are frame type (removable) and brazed type. The corrugation of the plate heat exchanger can make the fluid turbulent at a small flow rate, so that a higher surface heat transfer coefficient can be obtained. The surface heat transfer coefficient and the plate corrugation may have a greater relationship between the structure and the media activity.
(1) Reduce the thermal resistance of the dirt layer.
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 1mm, the heat transfer coefficient is reduced by about 10%. Therefore, it is necessary to pay attention to monitoring the water quality on both sides of the heat exchanger to prevent fouling of the plates and adhesion of debris in the water to the plates.
(2) Use heat transfer plates with high thermal conductivity
The plate material can be selected from austenitic stainless steel, titanium alloy, and copper alloy. Stainless steel has good thermal conductivity, thermal conductivity is about 14.4W/(m·K), high strength, good stamping function, not easy to be oxidized, lower price than titanium alloy and copper alloy, and is used in heating projects. But its ability to resist chloride ion corrosion is poor. The thickness of the plate does not have much to do with corrosion resistance, and is mainly related to the pressure-bearing ability of the plate heat exchanger. When the plate heat exchanger adopts a herringbone plate combination, the adjacent plates will be inverted, and the corrugations will contact each other to form a high density and uniform distribution. After the plate corner hole and edge sealing structure are perfected, the plate heat exchanger has better pressure-bearing ability.