Experimental Study Of Ship Fresh Water Circulation Cooling System Anti-scale By Cu-Zn-X Alloys

The fresh water circulation cooling system of marine is one of the vital systems of the marine power plants, whose performance is directly related to the safe operation of the ship. Scaling is a phenomenon of the cooling system and serious scaling can cause circulating water temperature rise and cooling system clogged. Even worse, it can affect the stable running of cooling system. Therefore, the scale prevention study of the fresh water circulation cooling system of marine is of great significance. Cu-Zn-X alloy is a kind of special alloy, which can remove the residual chlorine and soluble heavy metal in the water, control the growth of microbial and prevent the hard scale accumulation. The domestic and international researchers have been trying to apply the special alloy in fresh water treatment. This paper is based on the research results achived at home and abroad. The scale prevention mechanism of Cu-Zn-X alloy is studied in this paper. Based on this mechanism, the alloy material used for testing is prepared and a water circulation experimental apparatus used to test the anti-scaling performance is constructed. The scale prevention mechanism and anti-scaling effect of the alloy are analyzed by experiments. The main research contents are as follows:In order to make the application of the Cu-Zn-X alloy to prevent scale accumulation in the fresh water circulation cooling system of marine, in this paper, based on the scaling mechanism, the scale prevention mechanism of Cu-Zn-X alloy material is analyzed from the perspective of the electrochemical theory. The tiny primary batteries formed inside the alloy is supposed to have effects on the dissolution of the scale and crystallization sedimentation.According to the scale prevention mechanism of Cu-Zn-X alloy, the alloy material, which mainly contains copper, zinc, tin, nickel elements, is prepared and the anti-scaling device applied for testing is designed.The condition of fresh water circulation cooling system of marine is simulated, and the Cu-Zn-X alloy anti-scaling device is applied in designing anti-scaling experiments. By the experimental study on the effects of Cu-Zn-X alloy anti-scaling factors, the impacts of anti-scaling of alloy aperture, distance between the alloy sheets, liquid flow velocity, flow rate, temperature and so on is analyzed. The results show that:the effective area of the alloy has influence on the anti-scaling performance. When the alloy aperture is small and fluid flow speed is high, the effective area of alloy is large, and anti-scaling performance is good; a rise in temperature will accelerate the scale precipitation of calcium, but has little influence on the electrochemical reaction between the alloy and water as well as the anti-scaling performance of the alloy.