天然气计量误差分析

通常孔板流量计的测量精度能够满足ＧＢ２６２４－８１标准和ＳＹＬ０４－８３标准的要求，但在实际使用中，由于节流装置的设计、制造、安装和使用不符合标准要求等原因，影响了流量的测量精度。通过对孔板节流装置测量原理、安装要求、仪表的选择以及脉动流等诸多因素的分析，指出影响孔板流量计测量精度的根本因素是节流装置的几何形状和流动状态是否偏高设计标准，应对天然气密度、流束膨胀系数、流量系数等参数进行修正，使流量

Error Analysis on Natural Gas Measurement.

The conventional oriffice flowmeters, though accurate enough to meet such standards as GB2624-81 and SYL04-83, practically fail to reach their precision due to unqualified design, fabrication, installation and application of the restriction devices. Based on the analysis on such factors as working principles and installation requirements for oriffice restriction device, instrument selection, pulsation flow, etc. , the writer points out that the essential factor debasing the precision of oriffice flowmeters is the deviation from design of the geometric structure of restriction device and of the flow state. Some parameters, such as gas density, flow expansion coefficient, flow coefficient, etc. , shall be corrected so as to keep the flowmeter operate under normal conditions. In addition, automatic, continuous integration or a dedicated computer processing shall be adopted to maintain the measurement precision with minimum error.