Study On Liquid-Gas Pipeline Diameter Analyze System

Pipeline transportation, as main vehicle for oil-gas energy transportation, widely used all over the world, owing to its prominent advantage cannot be substituted for. But because of such reasons as nature or artificial destruct more and more accidents took place on pipelines. Safety problem of pipeline transportation has been think much of. Many kind of internal inspection methods and apparatus have been made due to pipeline internal defection. We should use Cleaning PIG and Geometry PIG first to cleaning the pipe and mapping its diameter change, so that to insure Pipeline Internal Inspection PIG fits for the pipe while operating. Based on the result get by Geometry PIG, we can replace or repair part of the pipe because the diameter has big change there, so that to prevent Internal Inspection PIG from being locked in.Geometry PIG should measure the whole line's diameter change relative to the normal diameter for locating while maintaining, and record the marking signal sending by transmitter mounted along pipeline in 1~2 km interval for eliminating the aggregate error made by odometer wheels in locating system. These years Geometry PIG used in our country are mainly imported from Germany. This kind of Geometry PIG is obviously out of date and not for universal use, so CNPPT ask us to develop the hardware and software of Geometry PIG for universal use.The Geometry PIG is made up of the hardware for collecting, storing and transmitting data, and the software which includes debugging software and data analyzing software for locating, data analyzing and making the final report. In this paper, first, based on requirement, we give a whole scheme. Then show that we have an innovative idea to use time reverse method while choosing odometer wheel. This method can decrease the error caused by alternating the odometer wheel's channel frequently and increase the precision while locating. In the following, we detailed introduce the hardware developing including data sample, data compress, data storage, data transmit, power management and real time clock, etc. Then expatiate developing of the software. Debugging software developed base on LabVIEW is used for demarcating before inspecting. Data analyzing software with powerful functions is developed base on Delphi. At last, a serial of dependable experiments are done on Geometry PIG to show this system has very good performance.