Experimental Study On The Fouling Characteristics Of The Enhanced Tubes

It is easy to see that enhanced tubes could strengthen the heat transfer, as it couldbetter increase the heat transfer efficiency, were widely used in the industrialproduction．More papers are on the heat transfer characteristics of enhanced tubes, butfew ones are on the fouling characteristics of the enhanced tubes．In this paper,experimental studies were carried out on the fouling characteristics, heat transfercharacteristics and the water quality parameters of the four tubes, the four tubeswhich include alternating elliptical axis tube, discrete double inclined ribs tube，corrugated tube and plain tube(copper)．Firstly, the characteristics of heat transfer were carried on the four enhancedtubes and compared with the ability of enhanced tubes heat transfer in differentvelocities．The results show that: Because different structure design could cause thedissimilar ability of heat transfer, discrete double inclined ribs tube has best effect onstrengthening the heat transfer by the help of inclined ribs．Secondly, CaCO3fouling characteristics of the alternating elliptical axis tubeand the plain tube were studied by the method of comparative experiments in threedifferences velocities and took half of the industrial experiments with the SonghuaRiver water．The results show that: Whether CaCO3or Songhua River water, in threedifferences velocities, the fouling resistance of alternating elliptical axis tube hasnearly closed．Thirdly, by use the Songhua River water as the cooling water in the tubes, thefouling characteristics were studied on the four enhanced tubes in three different flowvelocities and combined with the periodic change of flow field and wall shearstress．The results show that: the fouling resistance of discrete double inclined ribstube and alternating elliptical axis tube is less than others, this point is conformed tothe heat transfer characteristics and theoretical analysis． Finally, the water quality parameters of Songhua River water were analysed andnine water quality parameters were measured, the change of water quality parametersin the enhanced tubes, strengthen heat transfer and fouling deposit were an organicwhole, there was an internal connection between them．...