现状直埋供热管道增加支线位置的选择

Selection of Additional Branch Line Location for Existing Directly Buried Heating Pipeline

目前对直埋供热管道的受力分析都是基于新建管道第一次升温时的情况来进行的,而实际工程中常常需要在已投入运行的管道上开孔,仍采用上述方法进行应力计算将导致较大的误差,极端情况下甚至可能导致管道损坏。本文分析了直埋管道第一次升温、第一次降温的应力状态和位移变化,并着重分析了投入使用后,管道内应力分布随温度升降的变化规律,讨论了在已运行的管道上开大口径支管时会被拉断的极限情况,给出了后期增加三通开孔位置的选择方法和保护措施。

At present, the stress analysis of direct-buried heat supply pipeline is based on the new pipeline’s initial temperature rise. However, in practical projects, it is often necessary to cut holes on the pipeline that has been put into operation. If the above method is still used for stress calculation, it will lead to large errors, and even damage to the pipeline in extreme cases. This paper analyzes the stress and displacement caused by the first temperature rise and drop of direct-buried pipeline, emphatically analyzes the pipeline, which is already in operation, about the rule of its internal stress distribution changing with the temperature’s rise and fall, and further discusses the extreme condition that the pipe may be broken when large branch pipes are cut on the operating pipeline, and put forward the selection method and protection measures for the tee position.