Cathodic Protection For Crude Oil Storage Tank Bottom

Impressed current cathodic protection is one of the effective ways to delay the corrosion of outside base plate of the steel tank bottom.For large new oil storage tank,when choose impressed current anode,compare with other method such as deep-well anodes and anodeflex,net MMO titanium mixed metal oxide anode has the advantages of high protection niformity,easy construction and installation,long service life and remarkable economic benefit.So the use of net MMO anode current cathodic protection system is a most appropriate way for large steel tank bottom's corrosion protection.In impressed current cathodic protection system,the layout of reference electrode and anode is particularly critical.But as a part of the complicated oil tank construction project,tank bottom plate cathodic protection system's effect,many practical factors at the construction site inevitably.Many design parameters must be determined at the construction site.In this paper,by establishing the cathodic protection system simulator in the laboratory,touched on the impact on impressed current cathodic protection system's total power output under the same requirement when the laying place of reference electrode and MMO anode is different,which provides ideas for the selection of relevant parameters in engineering practice.In addition,in order to further understand and examine the actual working performance of the MMO anode used in the designed scheme,the output current density of the working anode was amplified at different magnification in the strong acid corrosion medium and the actual sand corrosion mediumrespectively.At the same time,monitor the electrochemical properties of the MMO anode,evaluate the electrochemical performance in different stages through the polarization curve,cyclic voltammetry and electrochemical impedance spectroscopy.The experimental results show that the service life of the selected MMO anode meets the requirements of standard specification,and its electrochemical parameters can be maintained on a stable performance platform for a long working time,which can meet the actual engineering needs.Based on the above theory and experiment,this paper designs a complete set of impressed current cathodic protection scheme of the outside base plate's corrosion protection fora external current of a single 10×10⁴ m³ steel oil tank.The program includes the selection and calculation of design parameters,the composition of each part of the system,as well as the installation and operation of the system,commissioning operation and management and maintenance methods.The cathodic protection system described in this protocol has beencompleted and put into use in the tank area.