兰成渝管道工程投产开阀方案探讨

The Valvesopening for the Production of LanChengYu Pipeline

兰成渝成品油管道是一条典型的大落差管道。通过对兰州—成都管段的输水联合试运过程的分析研究 ,从而确定能够保证管道安全运行的开阀方案。试运前管道充满水 ,随着首站泵开始投运 ,管道处于不稳定流动状态。研究中采用了特征线差分法求解该不稳定流动问题。求解中用非线性最小二乘法回归泵的特性曲线 ,用离心泵的相似定理处理启泵阶段泵转速变化对其流量和扬程的影响。根据兰成渝管道具体的边界条件开发了投产水力瞬变模拟软件。计算结果表明 ,投产时影响管道安全的主要因素是阀门开度和开阀时间。最终得到兰成渝管道投产开阀方案 ,即成县站、广元站和成都站阀门应分别在首站泵启动之后 2 30 ,4 0 0和 6 6 0s内完成顺序开启 ,其相对开度分别为 6 7% ,6 7%和 10 0 %。

Lanzhou-Chengdu-Chongqing Product Pipeline(LCCPP) is a typical differential height pipeline. Through the analysis of the water transportation process of LCCPP, the scheme of the opening of valves for keeping the pipeline safe was established. Before the process, the pipeline must be filled with water, with pump in the first station in operation, there is unsteady flow in the pipeline. Finite differential solution of characteristic method is used for it. Nonlinear least square method was used to get the characteristic curve of pump. Comparability theorem of centrifugal pump was used to get the relationship between flow rate and head when the rotational speed of pump changes at the beginning of operation. The simulation software of fluid transients for putting into production was developed according to the specific boundaries. The factors affecting the pipeline's safety are opening degree and opening time of valves. We get the opening plan: the valves of Chengxian station and Guangyuan station and Chengdu station should be opened within 230, 400, 660 s respectively and sequentially after the pumps going into operation. The opening degrees should be 67%, 67% and 100% respectively. The software can be used for shutting down and starting the pipeline.