摘要: |
目前,城市用水中约80%是工业用水,而工业用水中约80%是工业冷却水。为节约淡水,人们试图利用海水代替淡水做工业冷却水。但在海水冷却系统中,换热器的出口及其后续部分的钢铁设施由于海水温度较高(一般在50℃左右,有的还大于55℃),腐蚀现象相当严重,解决该部位的腐蚀防护问题是直接利用海水代替淡水做工业冷却水中不可缺少的一个环节。牺牲阳极是防止海水中钢铁设备腐蚀的一种行之有效的方法,但常用的几种牺牲阳极在该温度下不能适用。因此,找出牺牲阳极性能在不同温度下的变化规律,对研制能在高温下使用的牺牲阳极有着重要的理论和实际意义。
工作电位是牺牲阳极一项重要的性能指标。牺牲阳极只有具备了足够负的工作电位,才能在实际应用中保持足够的驱动电压(朱相荣等,1999;火时中,1988),达到长期使用的目的。有关文献报道了牺牲阳极添加元素对工作电位的影响(朱承德等,1997;Gurrappa1997;张信义等,1996),但哪些元素对阳极工作电位的影响更大些,元素对工作电位的影响是否有一定的规律,却均无报道。本文作者根据以上文献选择元素,自制了28种铝基牺牲阳极,并按国标GB4948-85的方法进行实验,用灰箱分析的数学方法对得到的数据进行分析,所得结果对研制高温海水中如何应用牺牲阳极有一定的指导作用。 |
关键词: 牺牲阳极 铝 工业冷却水 |
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基金项目:中国科学院海洋研究所调查研究报告第4380号。国家科委“九五”攻关项目,96-916-01-02号。 |
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GREY BOX ANALYSIS TO ASSESS THE INFLUENCE OF ADDITIONAL ELEMENTS IN ALUMINUM SACRIFICIAL ANODE ON ITS WORKING POTENTIAL AT VARIOUS TEMPERATURE |
LIU Xueqing1,2, ZHANG Jinglei1, GUO Gongyu1, WANG Jia1,3, LI Xiangbo1,2, LIU Yushan1
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1.Institute of Oceanology, The Chinese Academy of Sciences;2.Graduate School of the Chinese Academy of Sciences;3.State Key Laboratory for Corrosion and Protection of Metals
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Abstract: |
To save freshwater, people want to replace freshwater with seawater for cooling in industry. However, in seawater cooling system, the corrosion of the outlet of heat-exchanger and its following steel components is very serious. Application of Al sacrificial anode is one effective method to prevent steel equipment in seawater from corrosion, but at 50℃, Al anodes in common use are not applicable. So it is important to study the relevant rules governing Al anode performance at high temperature. Since the working potential is an important factor affecting the performance of Al anode, we try to find the rules governing how additional elements affect the working potential at various temperature.
Twenty-eight kinds of Al sacrificial anode were made for the experiment by the method of the Chinese National Standard GB4948-85. The interrelation of additional elements in the Al anode and the working potential of anode were studied by the method of grey box analysis. The results showed that the influencing order of elements on the working potential was the same on the whole; and that In, Zn, Mg and Ga were good additional elements for aluminum sacrificial anode in order to get negative working potential. |
Key words: seawater cooling system Al sacrificial anode |