TCPL - Hot Tap Connections II

管道的热抽头连接可以使新管道连接到正在运行的管道，而无需关闭正在运行的管道。由于一条管道的成本可能高达数亿美元甚至更多，因此避免因管道关闭而造成的收入损失对TcCPL来说是很有价值的。虽然目前已有将小直径管道连接到大直径管道的技术，但本研究将开发最先进的计算机模型来优化该技术，评估其设计的稳健性，或将该技术扩展到连接几乎相等直径的管道。焊接是一个非常复杂的过程，涉及到从熔化到凝固的整个材料加工过程，并在大约1厘米^3的焊接池中形成成品，大约需要1秒。显微组织控制焊缝性能。在低合金钢中，控制从焊缝穿过管壁的流动热量的对流系数和气体温度控制着焊缝的冷却速度和焊缝热影响区组织。这对于具有较高碳含量和铁素体-珠光体微观结构的旧管钢尤其重要。焊接缺陷，如气孔和裂纹可能是重要的。优化设计和工艺控制以生产最佳焊缝是一个重要的挑战。管道的优化设计，包括热抽头连接，包括热抽头的设计和制造，也是一个同样重要的挑战。

Hot tap connections of pipelines enable a new pipeline to be connected to an operating pipelinewithout shutting down the operating pipeline. Since a pipeline can cost hundreds of millions of dollars or more,avoiding the lost income that would be incurred by a shut down is valuable to TcCPL. Although the technologydo this for connecting smaller diameter pipes to larger diameter pipes exists, this research will develop state ofthe art computer models to optimize this technology, to assess the robustness of their designs or to extend thistechnology to connect pipes of nearly equal diameter.Welding is a very complex process that involves the complete material processing from melting tosolidification and shaping the finished product in a weld pool of roughly 1 cm^3 in times of roughly 1 second.The microstructure controls the weld properties. The convection coefficient that controls the flow heat throughthe pipe wall from the weld on the external wall of the pipe and the gas temperature control the cooling rate ofthe weld and weld heat-affected zone microstructure in low-alloy steels. This is particularly important in olderpipe steels that have higher carbon levels and ferrite-pearalite microstructure. Weld defects such as porosityand cracks can be important. Optimizing the design and control of the process to produce the best welds is animportant challenge. Optimizing the design of a pipe line, including hot tap connections including the designand fabrication of the hot tap is an equally important challenge.