Researching For Regional Cathodic Protection Of Urban Gas Stations

Regional cathodic protection technology is efficient in preventing buried metal pipelinesand facilities in stations from corrosion. However, the development of regional cathodicprotection technology is relatively backward in China. It has not been widely used in gaspumping or compression stations in China. There is a lack of systemic research on theselection of design parameters and problems in construction and inspection. Inappropriatedesign parameters or defects in construction may not only weaken the effect of regionalcathodic protection but also lead to potential safety risks. Therefore, it is significantlyimportant to carry out research on regional cathodic protection technology to providetheoretical guidance for design, construction, inspection and maintenance of regional cathodicprotection technology, so as to improve the effect of regional cathodic protection and ensurethe safety of stations.This research takes the regional cathodic protection in stations of An-Tuo-Shan gaspipeline as the subject and explores issues related to design, construction, inspection andeffectiveness evaluation. Numerical simulation is used to predict the effect of regionalcathodic protection. Real construction cases and measurement data are provided in the hopeof promoting application of regional cathodic protection technology in China.The regional cathodic protection technology protects all of the protected objects in anarea as a whole. The protected area features a lot of protected objects, complicated buriedmetal structures, severe interferences and shielding and high safety requirements. In order toachieve the optimum effect of protection, many factors should be taken into account in thedesign. This paper explores such issues as selection of protected object and protecting currentdensity, design of anode bed, as well as solutions to the problems of insulation andinterference.According to the layout of pipeline network in the station, a3-D digital model ofregional cathodic protection system is established. The cathodic protection potentialdistribution of distributed shallow anodes scheme is calculated and compared with themeasured data. There is a good match between them, which demonstrates that the numericalsimulation technology can be used for predicting the effect of regional cathodic protectionscheme. This is significantly important for improving the protection effect of regionalcathodic protection technology.