Research on Measurement Technology of Flue Gas Velocity Based on Optical Scintillation Induced by Fluctuation of Particulate Concentration

Zhibo  Ni; Tao  Pang; Yang  Yang; Fengzhong  Dong

doi:10.4236/jep.2014.510092

Zhibo Ni, Tao Pang, Yang Yang, Fengzhong Dong^*

Abstract: Based on the theory of optical scintillation induced by fluctuation of particulate concentration, a Gas Flow Velocity Measurement System (GFVMS) is proposed to measure the gas flow velocity in stack. Verification experiments on simulation flue indicate that, for the smoothing effect of transmitting and receiving apertures, optical scintillation induced by refractive index fluctuation is very weak. When particles are added into gas flow, the standard deviation of optical scintillation increased obviously. And when the particulate number concentration exceeds 4000/m3, the GFVMS can work normally, and the variation range of measured velocities is almost the same with that of Pitot tube. Sensitivity testing results show that, GFVMS is very sensitive to velocity change. Results of outfield experiment prove that, velocities measured by GFVMS are more stable and the average velocity (7.62/s) is very close to the statistical average (7.61 m/s) of velocities measured by Pitot tube at different points along optical path.

Keywords: Optical Scintillation, Flue Gas Velocity, Particulate Concentration, Cross Correlation

Cite this paper: Ni, Z. , Pang, T. , Yang, Y. and Dong, F. (2014) Research on Measurement Technology of Flue Gas Velocity Based on Optical Scintillation Induced by Fluctuation of Particulate Concentration. Journal of Environmental Protection, 5, 905-913. doi: 10.4236/jep.2014.510092.

References

[1] Andersson, B.J. (1958) On Measurement of Velocity by Pitottube. Arkivfor Matematik, 3, 391-394.
http://dx.doi.org/10.1007/BF02589492

[2] Stainback, P.C. and Nagabushana, K.A. Review of Hot-Wire Anemometry Techniques and the Range of Their Applicability for Various Flows. Electronic Journal of Fluids Engineering, 1-54.

[3] Denham, M.K., Briard, P. and Patrick, M.A. (1975) A Directionally-Sensitive Laser Anemometer for Velocity Measurements in Highly Turbulent Flows. Journal of Physics E: Scientific Instruments, 8, 681-683.
http://dx.doi.org/10.1088/0022-3735/8/8/019

[4] Wang, T.-I., Ochs, G.R. and Lawrence, R.S. (1981) Wind Measurements by the Temporal Cross-Correlation of the Optical Scintillations. Applied Optics, 20, 4073-4081.
http://dx.doi.org/10.1364/AO.20.004073

[5] Wang, T.-I. (2002) Optical Flow Sensor. USA Patent No. 6,369,881 B1.

[6] Tatarskii, V.I. (1961) Wave Propagation in Turbulent Medium. McGraw-Hill, New York.

[7] Chen, A.S., Hao, J.M., Zhou, Z.P., et al. (1999) Theoretical Solutions for Particulate Scintillation Monitors. Optics Communications, 166, 15-20.
http://dx.doi.org/10.1016/S0030-4018(99)00271-0

[8] Chen, A.S., Hao, J.M., Zhou, Z.P., et al. (2000) Particulate Concentration Measured from Scattered Light Fluctuations. Optics Letters, 25, 689-691.
http://dx.doi.org/10.1364/OL.25.000689

[9] Chen, A.S., Hao, J.M., Zhou, Z.P., et al. (2000) Measuring Particulate Concentration by Means of Scattered Light Scintillation. SPIE Proceeding, 4222, 71-75.

[10] Ralph, L., Roberson, G., Clark, M., et al. (1997) Evaluation of Continuous Particulate Matter (PM) Monitors for Coal-Fired Utility Boilers with Electrostatic Precipitators.
http://rmb-consulting.com/denpaper/rlrdenpa.htm

[11] Rao, R.-Z. (2005) Light Propagation in the Turbulent Atmosphere. Anhui Science & Technology Publishing House, Hefei.

[12] El-Wakil, S.A., Elgarayhi, A. and Elhanbaly, A. (2005) Transmission of Radiation through an Aerosol Medium. Journal of Quantitative Spectroscopy & Radiative Transfer, 93, 521-530.
http://dx.doi.org/10.1016/j.jqsrt.2004.10.005

[13] Chamaillard, K., Kleefeld, C., Jennings, S.G., et al. (2006) Light Scattering Properties of Sea-Salt Aerosol Particles Inferred from Modeling Studies and Ground-Based Measurements. Journal of Quantitative Spectroscopy & Radiative Transfer, 101, 498-511.
http://dx.doi.org/10.1016/j.jqsrt.2006.02.062

[14] Li, X.B., Xu, C.D., Luo, J., et al. (2009) Analysis on Two Methods of Measuring Refractive Index of Aerosol Particles. China Powder Science and Technology, 15, 72-74. (in Chinese)

[15] Huang, Y.-B., Huang, H.-L., Han, Y., et al. (2007) Measurement and Model Analysis of the Aerosol Optical Properties in the Regions of Hefei and Southeast Coast. Journal of Atmospheric and Environmental Optics, 2, 423-433. (in Chinese)

[16] Ministry of Environmental Protection (1997) Integrated Emission Standard of Air Pollutants. Integrated Emission Standard of Air Pollutants GB16297-1996. (in Chinese)

[17] KIMO Instrument (2007) CP 300 Operation Manual: Setting of 300 Series Transducer.