【作者】 刘春波；

【导师】 王新华；

【作者基本信息】 北京工业大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 管道运输以其高效率、低成本和安全可靠的优势在国民经济中发挥着越来越重要的作用。随着管道长时间的运营损耗、设备的自然老化、地理和气候环境的变化以及人为损坏等原因,泄漏故障时有发生,给人们的生命、财产和生存环境带来了巨大的潜在威胁,同时也会造成严重的资源浪费。因此,为了保证管道的安全运行,需要及时准确地检测管道运营状况,提高管道腐蚀防护状况分级的有效性及评价的准确性和科学性,以其最大限度地减少经济损失和环境污染。论文分析了管道腐蚀防护的各种检测技术原理、优缺点以及检测仪器特点,根据相关仪器资料、工程实践及现场试验明确了不同技术方法在埋地钢质管道外覆盖层检验检测中的适用性,并提出了埋地钢质管道外覆盖层检验检测组合技术方法。论文分析了周围环境对埋地管道腐蚀的分级评价、杂散电流强度评价、覆盖层状况评价及阴极保护有效性评价。提出了针对三层PE与沥青覆盖层的绝缘电阻率分级评价标准,针对三层PE与沥青覆盖层基于交流电流衰减法,考虑管道直径影响以db/m为单位的电流衰减率评价标准,以及不考虑管道直径影响以db/m~3为单位的电流衰减率评价标准。在详细分析影响埋地钢质管道腐蚀影响因素的基础上,建立了基于模糊评判理论的埋地钢质管道腐蚀防护状况综合评价模型。通过合理选取影响管道腐蚀的典型因素,依据一定的分级评价标准,建立评价集。利用层次分析法和灰色关联分析理论确定影响因素的权重大小,通过隶属函数法建立单因素评价矩阵,实现对各影响因素的模糊化处理。在综合考虑各影响因素权重的基础上,选取适当的模糊算子,通过定量分析的方法对管道的腐蚀防护状况进行评价。采用灰色关联分析法和工程数据的数理统计法研究了检测参量(土壤电阻率、管道埋深)对覆盖层状况的影响程度。实践表明,建立的模糊综合评价系统和覆盖层状况与检测参量相关性分析法具有一定的工程应用价值和可靠性。论文编制了埋地钢质管道腐蚀防护评价软件,用于实现对管道检测评价标准、评价结果的信息管理,对管道进行单因素评价计算、模糊综合评价计算以及防腐层缺陷状况与检测参量间相关性分析计算。更多还原

【Abstract】 Pipage with the dominances of high efficiency, low cost and safety credibility has playing an important role in the development of national economy. Leaking accidents happened frequently which can brings tremendous potential threat in people’s life, property and living environment, and serious waste of resource with the reason of long time pipeline run loss, equipment natural ageing, change of geography and climatic circumstance and man-made damage. Therefore, in order to ensure safe operation of pipeline there is need to detect condition of pipeline operation, increase the effectivity of corrosion protection grading for pipeline and accuracy and objectivity of evaluation, so economic losses and environmental pollution can be reduced maximatily.Every kind of detection know-why, merits and faults and characteristic of detection instruments for corrosion protection for pipeline are analyzed, applicability of coating detection for buried steel pipeline in applying different technical methods according to relational instrumental data, engineering practice and field experiment is defined, and combinatorial inspection technology of buried steel pipeline is raised.This paper analyzes evaluation of corrosion for buried pipeline graded by surrounding environment, evaluation of stray current, evaluation of coating status and evaluation of cathodic protection effectivity. Grading evaluation criterion of insulating resistivity, current attenuation rate evaluation criterion of considering influence of pipeline diameter unit by db/m and no considering influence of pipeline diameter unit by db/m~3 for 3PE and pitch coating are raised.The comprehensive evaluation model of corrosion protection for buried steel pipeline is established based on fuzzy evaluation theory by analyzing corrosive factors affecting buried steel pipeline in detail. According to the definite grading evaluation criterion, evaluation set is established by properly selecting typical corrosive factors affecting pipeline. The analytical hierarchy process (AHP) and grey correlation theory is applied in determining weights of affecting factors, and the method of membership grade function is used in establishing single factor evaluation matrix, which each impact factor can be fuzzed. Finally the quantitative analysis method is applied to evaluate corrosion protection status of pipeline by selecting proper fuzzy operator based on comprehensive considering weight of each affecting factor.Detection parameters that soil resistivity and pipeline depth to the influencing degree of coating conditions is researched by applying analytical hierarchy process and mathematical statistics of engineering data. Engineering application indicates that the fuzzy comprehensive evaluation system and correlation analysis between coating conditions and detection parameters have certain applying value and reliability.Evaluation software of corrosion protection for buried steel pipeline is built which can realizes information management for evaluation criterion of pipeline detection and evaluation results, which also can realizes calculation of single factor evaluation, fuzzy comprehensive evaluation and correlation analysis between coating defect conditions and detection parameters.更多还原