利用SCADA系统防止西气东输管道冰堵的预警逻辑

Warning logic of ice blockage with SCADA for West-to-East Gas Pipeline

西气东输二线输送介质为中亚进口气源,其输送介质的气质较差,为了避免管道冰堵造成分输量不足或严重的停输事件,分析了冰堵产生的原因:分输压差较大、分输时温降起伏大、水露点较高。基于此,建立了防止冰堵的预警逻辑:根据冰堵初期管道的工作调压阀后压力与开度、分输出站压力以及流量计流量等参数变化情况,判断是否形成了初期冰堵现象;通过对调压阀后压力和分输出站压力进行逻辑运算,得出初期冰堵位置,并使用Logix5000软件实现SCADA系统防冰堵预警逻辑。现场模拟应用结果表明:该方法能有效实现分输场站不同区域冰堵报警预判,为天然气管道预防冰堵提供了参考方法。

The 2nd West-to-East Gas Pipeline mainly transmits gas from central Asia. In order to avoid insuffi cient offtake throughput or serious shutdown event caused by ice blockage, the reasons of ice blockage is analyzed that that includes large offtake pressure differences, large fl uctuating temperature drop and higher water dew point. The changes of parameters, such as pressure behind pressure regulating valve and the opening, offtake outlet pressure, and fl owrate, are used to determine if initial ice blockage is formed. Logic operations on the pressure behind pressure regulating valve and offtake outlet pressure are conducted to obtain the initial ice blockage position. Moreover, Logix5000 software is applied for realizing logic of SCADA-based ice blockage warning. Field simulation results show that this method can effectively provide prediction and warning of ice blockage in different regions of offtake terminals. So, it is a good reference for the prevention of ice blockage of nature gas pipeline.