Thermodynamic Research Improves Energy Measurement in Natural Gas

This paper gives a brief overview of existing energy measurement systems for natural gas and presents a novel correlative concept for determining the energy contained in a gas. In addition, it provides information on the development and application of a new fundamental reference equation of state. This equation greatly improves prediction of caloric properties and therefore allows optimization of the use of critical nozzles for metering natural gas flows of varying qualities. Laboratory tests of the new energy measurement system have shown that the target uncertainty of 0.2% for the calorific value is routinely reached. A feasibility study currently underway examines the possibility of building a reference calorimeter with an uncertainty of 0.05%.