基于动态模拟的常压蒸馏装置SIL分析

安全完整性等级(Safety integrity level, SIL)作为安全仪表系统(Safety instrumented system, SIS)的定量指标，对装置的设计及风险分析都具有重要意义。常压蒸馏作为原油精制的关键过程，安全问题至关重要。为了保证常压装置安全运行，降低风险发生概率，减少财产损失，笔者提出了Dynamics SIL(Dyn SIL)的定量分析方法。首先，以传统的定性方法对常压塔顶压力联锁回路进行SIL分析，得出其SIL等级为N/A。然后，基于Dyn SIL以Aspen dynamics为工具模拟常压塔参数的偏离，分析重要变量应对外来扰动的响应情况，获得对应安全阀泄漏量的模拟结果。基于泄放量进行蒸汽云爆炸危害程度计算，确定了常压塔顶压力联锁回路的SIL等级为1。最后，模拟联锁回路的控制效果。结果表明，笔者所提出的定量分析方法比传统的SIL定性分析方法更为准确，从而验证了Dyn SIL定量分析方法的有效性。

SIL Analysis of Atmospheric Distillation Unit Based on Dynamics Simulations

As a quantitative index of safety instrumented system (SIS), the safety integrity level (SIL) is of great importance for device design and risk analysis. As a key process for crude oil refining, the safety of atmospheric distillation is very important. In this work, a quantitative Dynamics SIL (Dyn SIL) analysis method is proposed to guarantee the safe operation of atmospheric pressure devices, including reducing the probability of risks and decreasing property losses. First, the SIL analysis of interlock circuit on the top of atmospheric column was carried out by a traditional qualitative method, and the SIL grade was determined as N/A. Second, based on the method of Dyn SIL, Aspen dynamics was used to simulate the deviation of atmospheric pressure column and analyze the response of important variables in the presence of external disturbances. The simulation results of this corresponding leakage of safety valve were obtained by the dynamic simulation of system. Subsequently, the damage degree of the steam cloud explosion was calculated based on the discharge quantity, and the SIL grade of this atmospheric pressure column loop was determined as 1.Last, the control scheme was simulated for the interlock circuit. The results show that this quantitative analysis method (Dyn SIL) is more accurate than the traditional SIL qualitative analysis method, verifying the effectiveness of this method.