ISO 15970:2008 天然气 性能的测量 容积性能：密度、压力、温度和压缩系数
标准编号：ISO 15970:2008
中文名称：天然气 性能的测量 容积性能：密度、压力、温度和压缩系数
英文名称：Natural gas — Measurement of properties — Volumetric properties: density, pressure, temperature and compression factor
发布日期：2008-06
标准范围
ISO 15970:2008给出了测量主要用于体积计算和体积转换的天然气特性的要求和程序:参考和操作条件下的密度、压力、温度和压缩系数。仅考虑那些适合在天然气输配条件下现场操作的方法和仪器，它们安装在在线或在线上，并且不涉及气体成分的测定。ISO 15970:2008给出了当前使用的可商购且天然气行业感兴趣的仪器的示例。体积数据转换需要参考条件下的密度（有时称为正常、标准或甚至基础密度），并且可用于其他物理性质。使用观察到的线密度测量操作条件下的密度以用于质量流量测量和体积转换，并且可以用于其他物理性质。ISO 15970:2008涵盖基于振动元件的密度传感器，通常适用于5 kg/m3至250 kg/m3的测量范围。压力测量涉及差压、表压和绝对压力变送器。它考虑了模拟变送器和智能变送器（即基于微处理器的仪器），如果没有另外规定，相应的段落不加区别地指压变送器、绝对变送器和表压变送器。天然气中的温度测量在正常进行传输和分配的条件范围内进行(253K ISO 15970:2008 gives requirements and procedures for the measurement of the properties of natural gas that are used mainly for volume calculation and volume conversion: density at reference and at operating conditions, pressure, temperature and compression factor.Only those methods and instruments are considered that are suitable for field operation under the conditions of natural gas transmission and distribution, installed either in-line or on-line, and that do not involve the determination of the gas composition.ISO 15970:2008 gives examples for currently used instruments that are available commercially and of interest to the natural gas industry.The density at reference conditions (sometimes referred to as normal, standard or even base density) is required for conversion of volume data and can be used for other physical properties.Density at operating conditions is measured for mass-flow measurement and volume conversion using the observed line density and can be used for other physical properties. ISO 15970:2008 covers density transducers based on vibrating elements, normally suitable for measuring ranges of 5 kg/m3 to 250 kg/m3.Pressure measurement deals with differential, gauge and absolute pressure transmitters. It considers both analogue and smart transmitters (i.e. microprocessor based instruments) and, if not specified otherwise, the corresponding paragraphs refer to differential, absolute and gauge pressure transmitters without distinction.Temperature measurements in natural gas are performed within the range of conditions under which transmission and distribution are normally carried out (253 K < T < 338 K). In this field of application, resistance thermometer detectors (RTD) are generally used.The compression factor (also known as the compressibility factor or the real gas factor and given the symbol Z) appears, in particular, in equations governing volumetric metering. Moreover, the conversion of volume at metering conditions to volume at defined reference conditions can properly proceed with an accurate knowledge of Z at both relevant pressure and relevant temperature conditions.标准预览图
