摘要
氢气与天然气在物性参数上的差异会导致掺氢后管道及压缩机等水力元件的运行工况发生改变。目前,多数关于掺氢对管网运行工况影响的研究仅针对特定的边界条件及管网结构,研究的结果不具有普适性,研究结论也不相一致。基于此,本文建立了混合气体在管网系统中的流动仿真模型,逐一研究了不同边界条件组合下,掺氢之后管道沿线压力、流量、热值流量、水力坡降以及压缩机的进出站压力和压比等运行参数的理论变化规律。其中,管道的边界条件包括管道节点的压力、体积流量、质量流量以及热流量4种;压缩机的边界条件包括压力、转速以及压比3种控制条件。算例结果表明:掺氢后管道运行工况的变化情况与边界条件直接相关。当压缩机采用定出口压力或定压比控制时,管网工况参数与掺氢比之间有确定的关系,如随着掺氢比的增大,管道压力以一定的函数关系减小;压缩机在采用定转速控制时,管网工况参数的变化较为复杂,如随着掺氢比的增大,管道压力在某些情况下增加,而在某些情况下又会减小,需要针对具体场景进行分析。文章总结了不同边界条件下掺氢对天然气管网运行工况的普适影响,研究结论适用于任意支状管网,可为掺氢之后管网系统的运行调控提供理论指导。
The difference in physical parameters between hydrogen and natural gas will lead to changes in the operating conditions of the pipeline system after hydrogen blending.At present,most related studies only focused on specific boundary conditions and pipeline network structure.Therefore,the research results among them are not universal or consistent.To address this issue,this paper proposed a flow simulation model for mixed gas within the pipe network system.This model enables an in-depth investigation into the theoretical changes of various operating parameters.Specifically,parameters such as pressure,flow,heat flow,hydraulic gradient along the pipeline,inlet and outlet pressure of the compressor,and pressure ratio are analysed under different combinations of boundaries.The boundary conditions of the pipeline are classified into four types:pressure,volume flow rate,mass flow rate,and heat flow rate at the pipeline nodes.Meanwhile,the boundary conditions of the compressor consist of three control conditions:pressure,rotational speed,and pressure ratio.The computational results obtained from the Shaanxi-Beijing Natural Gas Pipeline and the Se-Ning-Lan Natural Gas Pipeline clearly demonstrate that the changes in pipeline oper-ation conditions after hydrogen doping are closely related to the boundary conditions.In cases where the compressor employs a fixed outlet pressure or fixed pressure ratio control method,a definite relationship can be observed between the operating parameters of the pipe network and the hydrogen blending ratio.For instance,as the hydrogen blending ratio increases,the pipeline pressure decreases following a specific function relationship.However,when the compressor adopts a fixed rotational speed control method,the variations in the operating parameters of the pipe network become more complex.As an example,with an increase in the hydrogen blending ratio,the pipeline pressure may increase in certain scenarios while decreasing in others,thereby necessitating analysis based on specific situations.This article comprehensively summarizes the universal influence of hydrogen blending on the operating conditions of the natural gas pipe network under diverse boundary conditions.The research conclusions hold true for any branched pipe network and possess significant value in providing theoretical guidance for the operation and control of the pipe network system after hydrogen blending.This is of great importance for ensuring the efficient and stable operation of the pipeline system in the context of hydrogen blending.It allows for a more accurate prediction and management of the system's performance,taking into account the various factors and boundary conditions that come into play.
作者
张博
梁永图
魏雪梅
徐宁
廖绮
邱睿
ZHANG Bo;LIANG Yongtu;WEI Xuemei;XU Ning;LIAO Qi;QIU Rui(Beijing Key Laboratory of Urban Oil and Gas Distribution Technology,China University of Petroleum-Beijing,Beijing 102249,China)
出处
《石油科学通报》
CAS
2024年第5期808-818,共11页
Petroleum Science Bulletin
基金
中国石油大学(北京)克拉玛依校区科研启动基金:基于可靠性的大型掺氢天然气管网高效运行优化,项目编号:KL01JB20230008
克拉玛依市科技计划基金:掺氢天然气管道可靠供应与安全运行关键技术研究,项目编号:2024hjcxrc0051联合资助。
关键词
天然气管道
掺氢
运行工况
压缩机
边界条件
natural gas pipeline
hydrogen blending
operation conditions
compressor station
boundary conditions