1PE装置使用超二十年压力容器评估研究

发布时间：2019-03-31 07:35

【摘要】：本课题针对1PE装置使用超二十年的压力容器开展评估工作。整个工作包括了对1PE装置设备的数据收集分析、现场检测和RBI评估。通过对历年的检测数据分析,了解了89台压力容器在运行了20-30年后内外壁的腐蚀情况,并以此计算了压力容器的腐蚀速率。部分压力容器在服役期间也进行了结构改造,比如夹套结构,换热器的密封结构等等。根据塑料事业部所提供的资料对装置的工艺与腐蚀情况进行的了解、API 581所提供的资料与数据、参考同类装置的失效分析资料并听取材料与腐蚀专家的意见,经综合分析后确定1PE装置中引起设备失效的主要损伤机理包括内部腐蚀减薄、外部损伤(大气腐蚀和保温层下腐蚀)。本文采用API 581方法,对1PE装置的压力容器进行风险评估,确定每设备风险的可能性因素和潜在后果,并确定每台设备的风险等级。以此提出设备检验建议,由厂方安排设备检验。本研究对4台超高压容器和22台高压容器根据当前设备壁厚进行强度校核,并对最小壁厚进行计算,确保这些高压容器在延长的服役期间能安全运行。由于1PE装置内储存的介质纯度很高,主要是乙烯,腐蚀性杂质含量不高,平均腐蚀速率较低,设备选材合理,因而介质腐蚀损伤机理情况基本不考虑。89台压力容器中换热器由于存在冷却水或高温蒸汽,易发生腐蚀,因此要加强监测或更换不锈钢材质。由于装置超期服役多年,装置的失效可能性等级逐年增加,且风险分布范围比较大,应当加大检测力度。
[Abstract]:This paper aims at the evaluation of pressure vessel which has been used for more than 20 years in 1PE plant. The whole work includes data collection and analysis, field inspection and RBI evaluation of 1PE equipment. The corrosion of 89 pressure vessels in the inner and outer walls after 20 years of operation has been studied by analyzing the inspection data in the past years, and the corrosion rate of the pressure vessels has been calculated. Some pressure vessels have been modified during service, such as jacket structure, sealing structure of heat exchanger and so on. Based on the information provided by the Plastics Department to understand the process and corrosion of the plant, the information and data provided by API 581, referring to the failure analysis data of similar devices, and listening to the advice of materials and corrosion experts, After comprehensive analysis, it is determined that the main damage mechanisms of 1PE equipment failure include internal corrosion thinning, external damage (atmospheric corrosion and under-insulation corrosion). In this paper, the API 581 method is used to evaluate the risk of the pressure vessel of the 1PE plant, to determine the possible factors and potential consequences of each equipment risk, and to determine the risk level of each equipment. Based on this, the equipment inspection suggestion is put forward, and the factory arranges the equipment inspection. In this study, the strength of 4 ultra-high pressure vessels and 22 high-pressure vessels were checked according to the wall thickness of the current equipment, and the minimum wall thickness was calculated to ensure the safe operation of these high-pressure vessels during extended service. Due to the high purity of the medium stored in the 1PE plant, mainly ethylene, low corrosive impurity content, low average corrosion rate and reasonable material selection of the equipment, In 89 pressure vessels, the heat exchangers are prone to corrosion due to the presence of cooling water or high temperature steam, so it is necessary to strengthen the monitoring or replacement of stainless steel materials. Since the equipment is out of service for many years, the possibility of failure of the device increases year by year, and the risk distribution range is relatively large, so the strength of detection should be increased.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH49

【参考文献】