库鄯线减压站的控制

Control Features of the Pressure Reducing Station in Koria-Shanshan Pipeline

库尔勒—鄯善输油管道是我国第一条穿过大高差地段的常温密闭输送管道。大高差将会使管道高点不满流,造成液柱分离;停输时造成管道最低点超压。解决大高差给管道运行带来危害的方法是增大低点处管道壁厚或设置减压站。而减压站的关键设备是减压阀。正确选择性能优越、安全可靠的减压阀,制定合理稳妥的控制方案,是保障管道安全运行的关键。介绍了所选减压阀的技术性能、减压站的工艺流程、控制原理、控制程序及减压站上游压力设定值的计算。指出为将清管清出的又大又硬的蜡块破碎,在进站方向加一个碎蜡器,其效果尚待检验;管道最高点压力,只用于监视报警不参与控制;管道最低点既不参与监视报警,也不参与控制等,都是设计中存在的问题。

Korla-Shanshan Crude Oil Pipeline is the fist pipeline in China, to adopt unheated tight line process and have a big elevation difference. Excessive elevation difference may result in slack flow and discountin-ued plugs over the peak point and, when pipeline system is shut down, over pressure within the lowest section. The solutions to counter elevation difference are heavy walled pipe and pressure reducing station. The key to safe pipeline operation is to properly select effective and reliable pressure reducing valve, which is critically important in pressure reducing station, and to initiate a reasonable control program. Introduced in the paper are the technical performances of the pressure reducing valve selected, the control principles and control process of the pressure reducing station, and the calculation of pressure settings upstream the station. Also mentioned are some problems needing further considerations in term of design; The effeciency of the wax breaker installed at inlet side of the station needs to be verified in removing the hard and bulky wax;The pressure measured in peak point is used only in monitoring and alarming but not in control, and the pressure in the lowest point is used neither in monitoring, alarming nor in control.