天然气.性能测量.发热值和沃泊指数

[中文适用范围]： 本国际标准涉及通过非分离法（即不涉及气体成分测定或基于成分计算的方法）测量天然气和天然气替代品的热值。它描述了用于此目的的各种仪器的操作原理，并为这些仪器的选择、评估、性能评估、安装和操作提供了指南。热值可以以质量基准、摩尔基准或更常见的体积基准表示。天然气体积基准的高位热值的工作范围通常在标准参考条件下（见 ISO 13443）为 30 MJ/m³ 至 45 MJ/m³。相应的沃布指数范围通常在 40 MJ/m³ 至 60 MJ/m³ 之间。本国际标准既不支持也不反驳任何商业制造商关于仪器性能的声明。其中心论点是，在任何特定应用中的适用性（定义为一系列特定的操作要求）只能通过精心设计的实验测试计划来评估。提供了这些测试适当内容的指南。 [外文原描述]： ISO 15971:2008 concerns the measurement of calorific value of natural gas and natural gas substitutes by non‑separative methods, i.e. methods that do not involve the determination of the gas composition, nor calculations from it. ISO 15971:2008 describes the principles of operation of a variety of instruments in use for this purpose, and provides guidelines for the selection, evaluation, performance assessment, installation and operation of these. Calorific values can be expressed on a mass basis, a molar basis or, more commonly, a volume basis. The working range for superior calorific value of natural gas, on the volume basis, is usually between 30 MJ/m 3 and 45 MJ/m 3 at standard reference conditions (see ISO 13443). The corresponding range for the Wobbe index is usually between 40 MJ/m 3 and 60 MJ/m 3 . ISO 15971:2008 neither endorses nor disputes the claims of any commercial manufacturer for the performance of an instrument. Its central thesis is that fitness-for-purpose in any particular application (defined in terms of a set of specific operational requirements) can be assessed only by means of a well-designed programme of experimental tests. Guidelines are provided for the proper content of these tests.