天然气涡轮流量计的应用与故障分析

Application of turbine flowmeter and failure analysis

基于天然气涡轮流量计的测量原理,探讨了其起始流量和安装方法。在适当的起始流量下,流量与转速呈线性关系;推荐在流量计入口和出口端各加接一定长度的直管段,若安装空间不能满足要求,可在阻流设备与流量计之间安装整流器,避免因气体流态改变影响流量计转子的转动。分析了天然气涡轮流量计在运行过程中的常见故障:天然气正常流动,流量计不计数;未作减量操作,流量显示逐渐下降;天然气不流动,流量显示不为零。针对以上故障,分别给出了相应的操作维护方法。结合应用实例,提出了天然气涡轮流量计在使用过程中的注意事项。

The initial flowrate of turbine flowmeter and its installation method in natural gas pipeline are discussed based on the metering principle.The flowrate has a linear relationship with rotational speed in the condition of an optimum initial flowrate.The inlet and outlet of flowmeter are recommended to elongate a straight pipe secton.If the installation space can not meet the demands,rectifier is advised to install between the resistance device and flowmeter in order to avoid the influence of gas flow pattern variation upon the running of flowmeter rotor.The common failures of turbine flowmeter happened in the course of running are analyzed.These failures are that flowmeter can not work in the case of normal flowing of gas;the display of gas flowrate is gradually decreased under the condition of normal running,the display of gas flowrate is not as 'null'in the condition of not flowing.The corresponding operation and maintenance methods are provided respectively.Also,the matters needed to pay more attention in use of flowmeter are presented combined with cases.