【作者】 王铮；

【导师】 靳世久；

【作者基本信息】 天津大学 ， 精密仪器及机械， 2007， 硕士

【摘要】 管道运输是与铁路、公路、航空、水运并驾齐驱的五大运输行业之一,已成为现代工业和国民经济的命脉。随着管道输送工业的发展,世界上石油输送管网的50%以上已运行了三十年以上,国内相当比例的原油管道也运行了二十年以上,老化程度严重,再加上不可避免的腐蚀、磨损和人为破坏等因素,管道泄漏现象频频发生。管道的泄漏不仅影响正常的生产,造成能源浪费和经济损失,由于所输介质的危险性和污染性,一旦发生事故还会造成巨大的生命财产损失和对环境的污染。随着经济发展对石油需求的增大,为了增强原油运输能力,一些重要的原油输送管线铺设了复线,构成双线原油管道输送系统。与单线管道相比,双线管道的运行工况十分复杂,给管道泄漏定位增加了很多不确定性。本文通过大量现场数据分析了双线系统运行工况的变化规律。在原有单线管道泄漏系统的基础上,增加了工况判断功能,由此可分析出泄漏发生在双线中的哪条管线。本文所研究的双线管道泄漏检测系统利用负压波定位原理,在负压波法中,各个子系统的时间同步精度严重影响着系统的定位精度。通过GPS提供的精准时间信号可以统一各个子系统的时间坐标,但是非实时系统对事件响应的时间是不确定的,这种不确定性同样会引入较大的同步误差,从而造成定位误差。本文引入RTOS(Real Time Operation System)作为开发平台,构建管道泄漏检测实时系统,实时系统能够及时响应外部事件的请求,在规定的时间内完成对该事件的处理。文中选择嵌入式实时Linux作为开发平台,详细分析了各种实时调度算法,对Linux的实时性进行了改造,使其成为实时操作系统。对检测系统的结构进行了模块的划分,并赋予不同的任务响应优先级,分别划入实时域和非实时域,使高优先级的校时模块得到及时的响应。该实时系统可以很好的减小时间同步误差,进而提高系统的定位精度,并且提高了系统的可靠性和扩展性。更多还原

【Abstract】 As one of the most important five means of transportation, pipeline transportation has become the artery of national economy and modern enterprise. With the development of pipeline industry, over 50% of the crude oil transported pipeline in the world have served for more than 30 years. And a considerable portion of the domestic crude oil transported pipeline have been in service for more than 20 years. As a result of serious pipelines aging, inevitable erosion , abrasion and human destroying, pipelines’ leak occurs frequently, which not only affect the normal production , but also course great loss of energy . It can even lead to considerable losses of lives and properties and serious pollution to the environment.As the demand of oil is increasing, the second pipeline is added to several important lines to raise transportation, which compose the doubly linked crude oil transported pipeline system. Compared with single pipeline, doubly linked line, which is much more complicated at function mode, introduces uncertainty to leak detection and location. After analyzing a lot of data, this paper gains the varying rules when the current mode shifts to another. Based on the single pipeline leak detection system, mode evaluation function is provided to judge which one is damaged alternatively. The system is based on negative pressure wave method, in which the precision of time synchronization influences the location accuracy evidently. GPS system, which provides accurate time signals, is adopted to unify the system time, but the response uncertainty of the unreal-time system also leads to synchronization error. Real Time Operation System is presented to design crude oil leak detection and location real-time system, in which system response latency is limited and can be evaluated. The embedded real-time Linux is presented as development platform. Some real-time scheduling methods are analyzed and adopted to construct real-time Linux. According to its function, different function module is set to different priority. Real-time system is to make sure that the module with high priority will be responded in time. Besides more accurate time synchronization and corresponding leak location accuracy, RTOS improves the system reliability and expansibility.更多还原