Research in 1999 and 2000 demonstrated that the method of using regression equations to determine the gas heating value can be used at arbitrary temperatures and pressures and with natural gases having a total concentration of diluents (nitrogen and carbon dioxide) of 6% by volume. To date, two energy meter modules have been designed and constructed to test the Southwest Research Institute (SwRI) energy meter concept. The current research focuses on the following tasks:

• Develop an inferential method for determining nitrogen in natural gas

• Improve the speed-of-sound measurement by evaluating newly available ultrasonic transducers, reviewing the chamber/target design, and ensuring accurate gas temperature measurements

• Redesign the electronic signal processing subsystem within the module to make the prototype more commercially manufacturable

• Test and evaluate the “energy meter module” using expanded laboratory conditions (greater temperatures, pressures, and diluents ranges) and field conditions

These necessary steps are currently in process to prepare the energy meter technology for commercialization.

Benefit of the Energy Flow Rate Meter Development Research to Industry

The natural gas industry traditionally performs gas composition assays by gas chromatography (GC) to measure heating value and determine gas properties (e.g., gas density) for flow measurement purposes. For custody transfer, energy flow rate is computed as the product of the separate flow rate and heating value measurements. Since 1998, Southwest Research Institute (SwRI) has been developing a simpler, more consolidated approach to natural gas energy rate measurement. Funded by the U.S. Department of Energy (DOE) and Gas Technology Institute (GTI), this new approach to measuring energy flow rate has shown promise for being able to reduce installation costs by an order of magnitude and reduce the number of measurement uncertainty sources.

The new approach to energy measurement that SwRI is developing exploits the unique nature of volume- and mass-based meters. It appears possible to add simple and inexpensive “gross characterization” sensors to convert conventional volume-based meters and mass-based meters to on-line energy rate measurement. This breakthrough, if achievable, will significantly reduce the cost of obtaining energy flow rate measurements in gas transmission pipelines because of reductions in capital equipment costs. Maintenance costs will also be reduced because less on-site equipment will be required at meter stations (e.g., in some instances, there will no longer be the need for an onsite GC). Since approximately 500 GCs are installed on gas transmission pipelines in the U.S. each year, $27.5 million in capital savings would be realized annually by eliminating these installations at an average cost savings of $55,000 per GC.

Primary Investigator: Eric Kelner, Senior Research Engineer

To find out how the Metering Research Facility can assist you with flow measurement, meter development, calibration, testing, and training, or for information about how you can contract with SwRI,  please please contact Terry Grimley at tgrimley@swri.org or (210) 522-2353.

mrf.swri.org