Hofmann (Beijing) Engineering Technology Co.,Ltd
Add:6F, East International Building, No.2 DongZhiMen Outside Street, DongCheng District, Beijing
1. Improve heat transfer coefficient of heat exchanger
Only by simultaneously increasing the surface heat transfer coefficient on both sides of the plate, and reducing the thermal resistance of the fouling layer, the plate with high thermal conductivity is used to reduce the thickness of the plate to effectively improve the heat transfer coefficient of the heat exchanger.
(1) Increasing the surface heat transfer coefficient of the plate due to the corrugation of the plate heat exchanger enables the fluid to generate turbulence at a small flow rate (Reynolds number - 150), so that a high surface heat transfer coefficient can be obtained, and the surface is transmitted. The thermal coefficient is related to the geometry of the corrugation of the slab and the flow state of the medium. The waveform of the plate includes a herringbone shape, a straight shape, a spherical shape, and the like. After years of research and experiments, it is found that the shape of the corrugated section is triangular (the sinusoidal surface has the largest heat transfer coefficient, the pressure drop is small, the stress distribution is uniform under pressure, but the processing is difficult?), the herringbone plate has a high surface pass. The thermal coefficient, and the larger the angle of the corrugation, the higher the medium flow velocity in the flow channel between the plates, and the greater the surface heat transfer coefficient.
(2) Austenitic stainless steel, titanium alloy, copper alloy, etc. may be selected from the material of the plate with high thermal conductivity. Stainless steel has good thermal conductivity, thermal conductivity of about 14. 4 W / (mK), high strength, good stamping performance, not easy to be oxidized, lower price than titanium alloy and copper alloy, most used in heating engineering, but its chlorine resistance Poor ionic corrosion.
(3) Reducing the thermal resistance of the fouling layer The key to reducing the thermal resistance of the fouling layer of the heat exchanger is to prevent scaling of the sheet. When the thickness of the plate is 1 mm, 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 scaling of the plate and prevent the inclusion of impurities in the water on the plate. Some heating units add chemicals to the heating medium in order to prevent water theft and corrosion of steel. Therefore, it is necessary to pay attention to the water and the adhesive causing impurities to contaminate the heat exchanger plates. If there is sticky debris in the water, it should be treated with a special filter. When using a drug, it is advisable to choose a non-stick agent.