天然气管线计划性放空回收数值仿真模拟  

Numerical simulation of planned venting recovery of gas pipeline

作　　者：左丽丽[1] 王珑云佳 雷宏峰 孙恒[1] 潘彪 田望 郭宇飞 孙晓阳 吴晓飞 郝千千 ZUO Lili;WANG Longyunjia;LEI Hongfeng;SUN Heng;PAN Biao;TIAN Wang;GUO Yufei;SUN Xiaoyang;WU Xiaofei;HAO Qianqian(National Engineering Research Center for Pipeline Safety,China University of Petroleum-Beijing,Beijing 102249,China;PipeChina Beijing Pipeline Co.Ltd.,Beijing 100000,China;PipeChina Science and Technology Research Institute,Tianjin 300457,China)

机构地区：[1]中国石油大学(北京)油气管道输送安全国家工程研究中心 [2]国家石油天然气管网集团北京管道有限公司 [3]国家石油天然气管网集团科学技术研究总院

出　　处：《天然气工业》2025年第1期175-186,共12页Natural Gas Industry

基　　金：国家自然科学基金面上项目“复杂供气管网大时滞非线性仿真模型构建与智能调控”(编号:52174064)。

摘　　要：天然气中甲烷的温室效应强度远高于二氧化碳,消除或减少输气管线放空作业中的天然气排放对实现双碳目标具有重要意义。为此,针对需计划性放空的输气管线,分别对采用下游压气站离心压缩机和移动式往复压缩机的2种天然气回收过程以及传统冷放空过程建立了瞬态仿真模型,并对放空回收所需总时间、放空气量、回收气量等参数进行了对比分析。研究结果表明:(1)采用隐式中心差分法求解这些模型,获得的回收时长、排放时长、回收气量、排放气量等参数与相应的TGNET软件仿真结果及放空过程实际数据的偏差均在±8%以内;(2)针对放空气回收过程的仿真模型,离心压缩机和往复压缩机需要考虑进行边界条件的转换;在放空过程的模拟中,需要考虑立管出口处压力和流速边界条件的转换;(3)针对输气管线计划性放空提出了3种天然气回收方案,其中方案1利用下游压气站的离心压缩机,方案2利用移动式往复压缩机,方案3为方案1和方案2的组合,即先用下游压气站的离心压缩机进行回收,当其进口压力降至允许最低值时,再切换至移动式往复式压缩机继续回收过程。结论认为:(1)方案1的回收时长最短但回收率最低,方案2的情况刚好相反,而方案3的回收率与方案2相近但回收时长介于方案1和方案2之间;(2)针对阀室间管线放空气回收方案的选择,离心压缩机与往复式压缩机结合进行回收的方案,可同时兼顾回收时长和回收效率,具有较好的经济性和可行性,因而具有较好的综合效果。The greenhouse effect intensity of methane in natural gas is much higher than that of carbon dioxide,so eliminating or reducing natural gas emissions in gas pipeline venting operation is of great significance in achieving the"dual-carbon"goals.For gas pipelines that needs planned venting,this paper establishes transient simulation models using two kinds of natural gas recovery processes(i.e.,the centrifugal compressor of downstream compressor station and the mobile reciprocating compressor)and the traditional cold venting process,and comparatively analyzes total time duration required for venting recovery,vented gas volume,recovered gas volume and other parameters.The following results are obtained.First,the recovery duration,venting duration,recovered gas volume,and vented gas volume obtained by using the implicit central difference method have the deviations within±8%from the simulation results of the corresponding TGNET software and the actual data of the venting process.Second,for the simulation model of the vented gas recovery process,the conversion of boundary conditions needs to be considered for centrifugal compressors and reciprocating compressors.In the simulation of the venting process,it is necessary to consider the conversion of pressure and flow velocity boundary conditions at the outlet of the riser.Third,three natural gas recovery schemes are prepared for the planned venting of gas pipeline.Specifically,scheme 1 uses the centrifugal compressor of downstream compressor station;scheme 2 uses the mobile reciprocating compressor;and scheme 3 is the combination of scheme 1 and scheme 2,that is,the centrifugal compressor of downstream compressor station is employed for recovery,and the mobile reciprocating compressor is activated for continued recovery when the inlet pressure drops to the minimum allowable value.In conclusion,scheme 1 has the shortest recovery duration,but the lowest recovery efficiency;scheme 2 exhibits the opposite results;scheme 3 shows a recovery efficiency similar to scheme 2,and

关 键 词：输气管线 放空 天然气回收 瞬态仿真 压缩机 方案优化 

分 类 号：TE832[石油与天然气工程—油气储运工程]