Due to the commercial transfer of billions of cubic meters of natural gases, the knowledge of the gross calorific value (GCV) of the main natural gas components and, in particular, of methane, is of outstanding interest. On the basis of previous work carried out by a Groupe Europeen de Recherches Gazieres (GERG)–Physikalisch-Technische Bundesanstalt collaboration, the so-called GERG calorimeter was further developed on the hardware as well as on the software side. With the renewed GERG calorimeter, the GCV of CH4 could be determined with unprecedented precision and accuracy. Important elements for improving the measuring methodology of flame calorimetry included the in situ calibration of the mass of the burned gas, the determination of the actual exhaust gas temperatures, and the detection of the water input by countercurrent water absorption from ambient air. For the first time, it was possible to determine the GCV not only via direct online weighing of the mass of burned gas but also via the stoichiometric water balance with a consistency of about 3.5 ppm. Based on 27 weighings of the mass of burned gas, the real-gas GCV of methane is determined as Hs(CH4) = 890 202.1 J mol−1 with a confidence interval of ±52.6 J mol−1 (t95% = 2.056). This value is by ΔHs/Hs = (−0.0436 ± 0.0059)% below the real-gas GCV of Hs(CH4) = (890 590 ± 380) J mol−1 (k = 2) converted according to ISO 6976:2016. The difference can be explained by systematic influences as well as by failures in the stoichiometric water balance in all other measurements.Due to the commercial transfer of billions of cubic meters of natural gases, the knowledge of the gross calorific value (GCV) of the main natural gas components and, in particular, of methane, is of outstanding interest. On the basis of previous work carried out by a Groupe Europeen de Recherches Gazieres (GERG)–Physikalisch-Technische Bundesanstalt collaboration, the so-called GERG calorimeter was further developed on the hardware as well as on the software side. With the renewed GERG calorimeter, the GCV of CH4 could be determined with unprecedented precision and accuracy. Important elements for improving the measuring methodology of flame calorimetry included the in situ calibration of the mass of the burned gas, the determination of the actual exhaust gas temperatures, and the detection of the water input by countercurrent water absorption from ambient air. For the first time, it was possible to determine the GCV not only via direct online weighing of the mass of burned gas but also via the stoichiome...

中文翻译：

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新型GERG热量计精确测量甲烷总热值

由于数十亿立方米天然气的商业转移，主要天然气成分的总热值 (GCV) 的知识，特别是甲烷，引起了人们极大的兴趣。在 Groupe Europeen de Recherches Gazieres (GERG)-Physikalisch-Technische Bundesanstalt 合作开展的先前工作的基础上，在硬件和软件方面进一步开发了所谓的 GERG 热量计。使用更新的 GERG 量热仪，可以以前所未有的精度和准确度测定 CH4 的 GCV。改进火焰量热法测量方法的重要因素包括燃烧气体质量的原位校准、实际废气温度的确定、以及通过从环境空气中逆流吸水来检测进水量。第一次，不仅可以通过直接在线称量燃烧气体的质量，还可以通过化学计量水天平（稠度约为 3.5 ppm）来确定 GCV。基于对已燃烧气体质量的 27 次称重，甲烷的真实气体 GCV 确定为 Hs(CH4) = 890 202.1 J mol-1，置信区间为 ±52.6 J mol-1 (t95% = 2.056)。该值比 Hs(CH4) = (890 590 ± 380) J mol−1 (k = 2) 的实际气体 GCV 低 ΔHs/Hs = (-0.0436 ± 0.0059)%，根据 ISO 6976:2016 转换。这种差异可以通过系统影响以及所有其他测量中化学计量水平衡的失败来解释。 由于数十亿立方米的天然气的商业转移，对主要天然气成分（尤其是甲烷）的总热值 (GCV) 的了解非常令人感兴趣。在 Groupe Europeen de Recherches Gazieres (GERG)-Physikalisch-Technische Bundesanstalt 合作开展的先前工作的基础上，在硬件和软件方面进一步开发了所谓的 GERG 热量计。使用更新的 GERG 热量计，可以以前所未有的精度和准确度测定 CH4 的 GCV。改进火焰量热法测量方法的重要因素包括燃烧气体质量的原位校准、实际废气温度的确定以及通过从环境空气中逆流吸水来检测水输入。首次，