MONITORING POWER PLANT EFFICIENCY USING THE MICROWAVE-EXCITED PHOTOACOUSTIC EFFECT TO MEASURE UNBURNED CARBON

[摘要] Three test instruments are being evaluated to determine the feasibility of using photoacoustic technology for measuring unburned carbon in fly ash. The first test instrument is a single microwave frequency system previously constructed to measure photoacoustic signals in an off-line configuration. A second off-line instrument was constructed based in part on lessons learned with the first instrument, but which also expands the capabilities of the first instrument. Improvements include a control loop to allow more constant microwave power output and an ability to operate over a range of microwave frequencies. The third instrument, the on-line version of the fly ash monitor, has been designed, constructed, and initial efficiency tests have been conducted on the monitor's electrical components. Off-line photoacoustic microwave spectra of fly ash and coal were collected and analyzed, and the spectra demonstrated a linear correlation between the photoacoustic response and the carbon content in either fly ash or coal. Modifications were made to the on-line fly ash monitor to incorporate a dual-accelerometer system that would provide active noise control. Several experiments were conducted with flowing and non-flowing fly ash samples.

[发布日期] 2004-10-01 [发布机构] Iowa State University (United States)

[关键词] Coal;Spectra;Monitoring;Microwave Spectra;01 Coal, Lignite, And Peat