常压设备氯腐蚀的动态风险预测模型

针对原油加工过程中常压设备因氯腐蚀引起穿孔、进而导致泄漏事故发生的问题,结合氯腐蚀试验与动态预测方法,建立常压设备氯腐蚀的动态风险预测模型,从而及时规避腐蚀泄漏风险。首先,针对常压塔设备材料Q345钢开展挂片腐蚀试验,在获取试验数据的基础上,采用灰色理论建立质量损失预测模型,通过计算可得随时间变化的腐蚀速率和累积腐蚀厚度;除此之外,运用马尔科夫链预测腐蚀状态的概率。结果表明,采用灰色理论建立的质量损失预测模型精度良好,且此模型可得任意时刻腐蚀速率及累积腐蚀厚度;与此同时,基于马尔科夫链建立的腐蚀状态概率预测模型表明,Q345钢在第3年和第15年分别进入腐蚀加速和腐蚀穿孔阶段,该结论可作为制定检维修计划的参考。

Dynamic Risk Prediction Model of Chlorine Corrosion of Atmospheric Pressure Equipment

In order to solve the problem that the atmospheric pressure equipment in crude oil processing is perforated due to corrosion, which leads to the occurrence of leakage accident, the dynamic risk prediction model of chloride corrosion of atmospheric pressure equipment was established via combining chlorination corrosion test and dynamic prediction method, so as to avoid the leakage accident. Firstly, Q345, which is the most widely used steel of atmospheric pressure tower, is used to carry out corrosion experiment. Then the prediction model of weight loss was set up by gray theory based on the experimental data, and the corrosion rate over time and cumulative corrosion depth can be obtained by calculation. In addition, the probability of corrosion status can be predicted by using Markov chain. The results show that the mass loss prediction model established by GM(1, 1) has a good accuracy, and the corrosion rate and accumulated corrosion thickness can be obtained at any time by calculation;at the same time, the probabilistic prediction model of corrosion state based on the Markov chain shows that the Q345 steel enters the corrosion acceleration and corrosion perforation stages from the third and fifteenth years, respectively, which can be used as a reference for the development of maintenance plans.