针对DN1 000 mm的长距离LNG输送管道BOG(闪蒸气)预冷过程,建立一维流动传热模型,对预冷过程进行了模拟分析.整体壁面温度下降速率最大不超过10 K/h,计算时间步长取10s,计算得出761.2 m的LNG输运管道冷却到154.5 K(-118.65℃)左右所需时间为30.25 h.分析了整个预冷过程中,管道壁面温度,管内BOG气体温度和BOG气体进口质量流量的变化趋势,还分析了输运管道中管道变径处温度阶跃突变的现象和原因,同时分析不同因素对管道预冷过程的影响.从以上影响预冷过程的主要因素的分析得出整个预冷过程的规律.%According to BOG pre-cooling process of long distance LNG transport pipeline, one-dimensional flow heat transfer model was established to simulate pre-cooling process. The largest pipe temperature cool-down velocity was 10 K/h and compute step time was 10 s. Calculation result show that total cooling time was 30. 25 h for 761. 2 m LNG pipe cooled down to 154. 5 K. Through cooling process, changing trend of pipeline temperature, BOG temperature, inlet BOG mass-flow and phenomenon at pipe diameter changing position were all analysed. Result show that different factor has different influence on the pre-cooling process.
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