| The paper established a physical model of the potential distribution of pipeline cathodicprotection and derived the corresponding mathematical model, using the boundary elementmethod to discretize the model and solving by programming. The effect of anode buried ways,depth and horizontal distance of the anode from the pipeline on the pipeline cathodicprotection potential distribution was studied through the program and BEASY simulationsoftware. BEASY Software was used to simulate the potential distribution of the station pipenetwork on which anodic sacrifice protection and impressed current protection was imposed.The potential distribution of the pipe network was analyzed by changing the number, location,material of the buried sacrificial anode and the output current of the auxiliary anode. Finally,the effect of the trunk auxiliary anode on regional station was analyzed by using BEASYSoftware and minimized the effect by changing the location of the auxiliary anode.The physical model established in this paper is more in line with reality.The governingequations can be well discretized by the tube unit model with the boundary element method.The comparison of the results calculated by the interior design experiment withprogramming found, the wrote program is proved to be correct by comparing the calculationresults with the interior design experiment data, which provide guarantee for using thisprogram to research the effect of anode on cathodic protection.Through the study of the impact of the way of the anode buried to the potentialdistribution of pipeline cathodic protection,it was found that: in the case of the total outputcurrent was the same, the distribution of potential of the flexible anode was most uniform,approximated as a straight line; distributed anode potential distribution to show wavy at theanode near the trough, uneven potential distribution; deep anode potential distribution to showa funnel-shaped, and minimum in the deep at the anode potential, and as close to the increasein the position of the anode, the potential decay quickly, the potential distribution was veryuneven. Through the study of the impact of the horizontal distance between the anode and thepipeline to the potential distribution of pipeline cathodic protection,it was found that: as thedistance increased, the pipeline-earth electrical potential near the anode to a positive offset,but for the entire pipeline, the potential distribution of pipeline was more uniform.The study of the impact of the anode buried depth on the pipeline cathodic protectionpotential distribution found that: the anode cathodic protection potential near the anodeshifted correspondingly with the anode buried depth increased; With the increase of protectiondistance and the anode burial depth, cathodic protection potential shifted negatively. Overall,With the anode depth increased, the cathodic protection potential becomed more uniform.View from the cathodic protection of a station, without considering about ground pipenetwork, sacrificial anode cathodic protection maked the station underground pipe network inthe scope of the cathodic protection easily, and the station pipe-to-soil potential had no largechange with the change of the location of the sacrificial anode and the potential distributionwas very uniform; for impressed current cathodic protection, pipeline cathodic protectionpotential rised with the output of anode current reduced, but it still could be in betterprotection (reduced from1A to0.2A). However, when decreased to0.1A, some parts of thepipeline potential was close to-0.85V, and therefore that the output current0.2A wasrecommended.The simulation results of a station affected by the auxiliary anode of long distance trunkfound: the existing auxiliary anode had a great influence on station underground pipenetwork pipe-to-soil potential distribution; the influence on the station could be reduced bytaking the auxiliary away from the station, when moving to a certain distance (200m) itreduced to a negligible level. |
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