大型原油罐区的阴极保护

Cathode Protection of Large Crude Oil Tank Farm

论述了原油罐的腐蚀机理与阴极保护原理 ,介绍了中国石化股份有限公司沧州分公司大型原油罐区的整体阴极保护设计与安装情况。该公司对一座 5 0 0 0 0m3 原油罐的底板内壁实施了牺牲阳极保护 ,待保护面积为 30 14m2 ,罐底用锗系铝合金阳极 2 15块 (单重 14kg) ,罐壁用 2 5块 (单重 8kg) ,实测保护电位可以达到- 0 .94V ,设计寿命为 8年。其罐底外表面及埋地管道则采用外加电流阴极保护技术 ,并于 2 0 0 1年底投用 ,保护电位控制在 - 0 .9～ - 1.1V。由于采用了深井阳极技术 ,使投资大大降低 ,效果良好。

The corrosion mechanisms of crude oil storage tanks and cathode protection principles are introduced. The engineering and installation of integrated cathode protection system of the large crude oil tank farm of Cangzhou Petrochemical Co., Ltd./SINOPEC are described. The sacrificing anode protection was applied for the bottom plates of a 50,000 m3 crude oil tank with an protection area of 3014 m2. 215 pieces (single piece weight 14 kg) of aluminum alloy anode were installed for bottom plates and 25 pieces (single piece weight 8 kg) for wall plates. The measured protection voltage was -0.94V and design service life was 8 years. The external surface of the bottom plate and buried pipelines were protected by applied current system, which was commissioned at the end of 2001. The protection voltage is controlled at -0.9～-1.1V. As the deep well sacrificing anode technology is applied, the investment has been greatly reduced and protection performance is satisfactory.