摘要
在天然气末端输配气站,多用户共用调压系统是较为常见的工艺设计。随着乡镇小民用气等小流量用户和CNG加气站等间歇用气用户(以下简称特殊用户)日益增长,其部分用户出现了较大的计量输差。通过分析和原因排查,确认此类用户较大输差是由于计量仪表自身单向计量特性和受局部气流反向的影响所致,而局部气流反向则与共用调压系统的大流量用户的流量变化密切相关。对此类用户增设了单独的调压阀或单流阀(止回阀),其输差水平均大幅下降并回归正常。通过两个典型案例,揭示了多用户共用调压系统造成特殊用户形成较大计量输差的过程,指出特殊用户应设计单独的调压阀或单流阀,用于防范计量风险。
Multi-user common pressure regulating system is a process popularly used at the gas offtake terminal station. With increasing low flowrate users（e.g. small domestic gas users in towns） and intermittent gas users（e.g. CNG filling station）, collectively referred to as special users, some users run up against significant metering errors. Through analysis and diagnosis, it is confirmed that such errors are resulted from the one-way metering function of the flowmeters and the inversion of local gas flow, while the latter depends on the flowrate variation frequency of high flowrate users within the common pressure regulating system. For these users, a separate pressure control valve or non-return/check value is added, which has enabled system to be normal by reducing the errors. In this paper, two typical cases are discussed to reveal the process how the common pressure regulating system leads to large metering error for special users, and it is pointed out that separate pressure control valve or non-return valve should be designed for special users, so as to avoid metering risks.
出处
《油气储运》
CAS
北大核心
2015年第1期100-103,共4页
Oil & Gas Storage and Transportation
关键词
天然气
调压
小流量
间歇用气
双向计量
输差
流量计
natural gas
pressure regulating
low flowrate
intermittent gas use
two-way metering
metering error
flowmeter
