Investigation On The Effects Of The Low Energy Surface Upon Heat Transfer And Fouling Performance

In the power, petroleum, chemical industries and other fields, the fouling problem has been the most difficult one which needs to be solved urgently.The efficiency of heat transfer will fall down while the consumption of energy and material will increase for the existence of fouling.Teflon coating belongs to low surface energy fluorocarbon material,which has superior performance in the field of anti-fouling and poorer characteristics of heat transfer.Nano-TiO2 has special characteristics.Combined the anti-fouling properties of the Teflon coating with hydrophobic of nano-TiO2, the low energy surfaces are produced in this paper.The results confirmed a great relationship between the coating surface characteristics and the fouling formation.First, the surface roughness, contact angle, surface energy of solid materials and interfacial energy between solid material and liquid were measured and calculated, Results show that adding different content nano-TiO2 in PFA could reduce the surface energy, improve the heat transfer surface hydrophobic.Second, validate the experiment system in the state of cleanliness and analysis of the experimental error .And the error was in accord with the experimental requirements. The different coating surface was scanned and analyzed. The result shows that the micro-structure was different. The relationships between the material surface properties (the surface roughness, contact angle, surface energy of solid materials and interfacial energy between solid material and liquid) and characteristics of heat transfer were studied experimentally. Meanwhile, by explaining the basic conception of surface energy, the relation between surface energy and heat exchanger performance is presented.At last, the relationships between the material surface properties and characteristics of fouling were studied experimentally through weight method. At the same time, the theories were applied to analysis of the influence of the material surface properties. The calculated results were in accord with the experimental results, thus verified the experimental validity.