LNG接收站管廊结构设计

Structural design of LNG receiving terminal pipe rack

液化天然气(Liquified Natural Gas,LNG)接收站管廊作为各类管线支撑结构,连接码头卸料、站内储存、气化、外输等工艺单元以及公用工程,布置、荷载及工况较多,对接收站工程量影响较大,对工期、后期维护要求高。在项目初设阶段,管廊结构形式的选择可为业主预算提供基础;在详设阶段,对总包方的成本及工期控制至关重要。以某新建LNG接收站为例,综合考虑管线荷载、布置、工况、施工、经济因素,提出管廊选型依据,进行具体建模;计算分析对比管廊正常操作、水击两种基本工况的差别,提出了包络设计;同时同条件对比了砼—钢混合结构与全钢结构管廊的经济差别,方便项目决策。管道荷载准确性对管廊结构设计影响较大,因此设计前期对专业互提条件需引起足够重视。研究结果为后续LNG接收站管廊结构设计提供了参考。

The Liquified Natural Gas(LNG) receiving terminal pipe rack,as a supporting structure for various piping,connects process units such as terminal unloading,terminal storage,gasification,and export transportation,as well as utility systems.There is a wide range of piping layout arrangement and pipe rack is affected by many different loads and working conditions,which has a significant impact on the engineering work scope of the receiving terminal.Hence,it is necessary to put forward higher requirements for construction period and subsequent maintenance.In the initial design stage of the project,the selection of the pipe rack structure can provide a basis for the estimation of owner's budget.In the detailed design stage,the chosen pipe rack structure is crucial in the cost and schedule control for the main contractor.Taking a newly built receiving terminal as an example,taking into account piping load,layout,working conditions,construction,and economic factors,this paper proposes a selection basis for pipe racks,and conducts specific modeling,calculation and analysis to compare the differences between normal operation and water hammer condition of pipe racks,and proposes design envelope.At the same time,the economic differences between concrete steel hybrid structure and all steel structure pipe rack were compared under the same conditions,to facilitate project decision-making.The accuracy of piping load calculations has a significant impact on the design of pipe rack structures;therefore,sufficient attention should be paid to the compilation of multi-discipline design data and design conditions in the early stage of design.The research results provide a reference for the design of subsequent receiving terminal pipe rack structure.