API RP 581熱交換器管束風險評估檢查技術在石化製程設備的應用

Application of the API RP 581 Risk-Based Inspection Technology On the Heat Exchange Tube Bundles in Petro-Chemical Process Systems

顏士雄(Shih-Hsiung Yen)

指導教授 ： 林中彥

國立虎尾科技大學/工程學院/航空與電子科技研究所/碩士(2012年)

https://doi.org/10.6827/NFU.2012.00010

摘要

本研究的主要目的是以模擬的石化業界運作模式為案例，導入美國石油協會(American Petroleum Institute, API)所發展出來的熱交換器管束風險評估檢查技術，以預測熱交換器組件故障時機，和評估最佳的設備檢查和更換周期。
熱交換器在煉油製程中占有非常重要的角色，由於受到原油及冷凝劑中腐蝕性成分和細微固體雜質顆粒的沖刷，熱交換器管線會逐漸被腐蝕變薄，導致管壁遭到侵蝕破裂，由於非計畫性的停車檢查、維修、和設備更換所造成之生產線損失龐大，而其所潛藏的工安與環保問題更是不容忽視，本研究即在此背景下，以可靠度以及維護成本的觀點，導入API RP 581熱交換器管束風險評估檢查技術，以預估熱交換器管束壽命、以及評估最佳更換時機。在研究方法方面，本研究採用Weibull故障分佈函數模型，以熱交換器管束檢查和汰換的歷史數據，去預測現行操作中熱交換器設備的可靠度壽命。

研究結果顯示利用Weibull故障分佈函數模型預估設備平均失效時間MTTF(Mean Time To Failure)，參考數據越多，壽命評估的越準確；以管束失效後果分析進行風險評估，經由維修天數可以計算出非計畫維修成本與計畫性維修成本的差距，研究結果同時可以顯示出以管束失效後果分析有效預測管束最佳的更換時間；將管束失效後果分析配合回報率ROR參數依照檢查時的數據判斷管束是否維修或著是更換，在回報率ROR越高的情況下，距離更換裝備的時間越長；由熱交換器管壁可以預估管束壽命與管束更換時間，根據定義不同的最低可用管壁厚度，可以影響到熱交換器管束的使用壽命；此一結果表示管壁厚度在壽命與換管時間中是一個很重要的因素，掌握精確的管束數據配合風險評估，期能改善熱交換器之成本操作及使用壽命。

關鍵字

風險評估 ； 可靠度 ； 維護成本 ； Weibull故障分佈 ； 平均失效時間

並列摘要

The purpose of this research is to predict the failure timing of heat exchanger bundles and evaluate the optimal equipment inspection and replacement cycle through a risk assessment inspection technique developed by the American Petroleum Institute (API). The technique is validated with a simulated petrochemical industry operation.
Heat exchanger plays a very important role in the fuel-refining process. Due to the corrosion from corrosive components and the erosion from fine solid particles in crude oil and refrigerant, the thickness of pipe wall of heat exchangers pipelines will gradually thin out, resulting in wall rupture, which in turns calls for an unscheduled maintenance. Since the unscheduled inspection, maintenance and component replacement of the equipments incurred by the unexpected failure often lead to huge out-of-production loss, let alone the potential industrial safety and ecological concerns which should not be ignored. In view of this context, this study, focusing on the consideration of reliability and maintenance cost, applies the API RP 581 risk-based inspection technology to predict the useful life and assess the optimal replacement timing of the heat exchange tube bundles. Weibull distribution function is adopted to simulate the failure model. Through input of historical data of when specific heat exchanger tube bundles were inspected and/or replaced, the reliability life of current heat exchanger equipment is predicted.
The results show that the Weibull failure distribution function model to estimate the bundle mean time to failure MTTF (Mean Time To Failure)reference more data, more accurate life assessment; The consequences of failure to bundle conduct a risk assessment, unplanned maintenance costs and a planned maintenance cost of the gap can be calculated through the maintenance of the number of days, results can be displayed to bundle the consequences of failure analysis to predict the effective bundle the optimal replacement time; Will bundle the consequences of failure analysis with the rate of return ROR parameters in accordance with the inspection data to determine the bundle whether the repair or replacement, the longer distance to replace equipment in case the higher the rate of return ROR; Can estimate the bundle life and control of the replacement time, according to the different definitions of the minimum wall thickness available, can affect the service life of heat exchanger tube bundle heat exchanger wall; This result represents the wall thickness is a very important factor in the life of the bundle replacement time to grasp the precise bundle of data with the risk assessment period can improve the cost of operation and service life of the heat exchanger.

並列關鍵字

Risk Assessment ； Reliability ； Maintenance Cost ； Weibull Distribution Function ； Mean Time To Failure

參考文獻

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