| Author(s): |
Lee J. Gorny; Keith A. Gillis; Michael R. Moldover; |
| Title: |
TESTING LONG-WAVELENGTH ACOUSTIC FLOWMETER CONCEPTS FOR FLUE GAS FLOWS |
| Published: |
June 22, 2012 |
| Abstract: |
As a part of NIST’s program to standardize measurements of greenhouse gas emissions, we are developing a long-wavelength acoustic flowmeter (LWAF) for accurate, economical measurements of exhaust flows from coal-burning power plants. Measurements of the flue gas mass flowrate combined with the gas’s composition are used to determine the emitted CO2 and other by-products of combustion. Today, such measurements have uncertainties of 5% or more due to the large size of the flue-gas stacks and the flow’s non-uniform, unsteady, and swirling profile. A LWAF averages the spatial non-uniformities of the axial velocity over the entire cross section in a manner insensitive to flow distortions. In contrast, conventional techniques measure gas flow only at isolated points or averaged along chord across the stack. We constructed a 1:100 scale, calibrated flow facility for the initial development of a LWAF. In preliminary tests of three flow metering methods, uncertainties ranged from 1.4% to 4.9%, compared to our target uncertainty of 1%. We present the principle behind the LWAF, our design considerations, and the current performance of time and frequency-based approaches to metering, and describe technical challenges that must be overcome to use a LWAF at a full-scale power plant. |
| Proceedings: |
8th International Symposium on Fluid Flow Measurement |
| Pages: |
15 pp. |
| Location: |
Colorado Springs, CO |
| Dates: |
June 18-22, 2012 |
| Keywords: |
flow meter; acoustic; long-wavelength; calibration; frequency response function; sound propagation; greenhouse gas; power plant; emissions; flue gas |
| Research Areas: |
Measurement Standards, Flow, Calibrations, Standards, Manufacturing, Metrology |
| PDF version: |
 Click here to retrieve PDF version of paper (1MB) |
