THERMAL SCIENCE
International Scientific Journal
INVESTIGATION ON ASH FOULING FORMATION OF INDUCED FAN BLADE AND HEAT EXCHANGER SURFACE IN A 1000MW COAL-FIRED POWER PLANT
ABSTRACT
The control of fouling deposition on the main equipment has always been an im-portant issue concerned by scientific research and industrial application. How-ever, severe fouling deposits on the induced fan blade and the low temperature economiser were found in a 1000 MW coal-fired power plant with ultra-low emission. The deposit samples were collected and analysed through X-ray dif-fraction spectrometer, X-ray fluorescence, elemental analyser and SEM with en-ergy dispersive spectrometers. The result shows that the deposits are mainly composed of tschermigite (NH4)Al(SO4)2 · 12H2O, letovicite (NH4)3H(SO4)2, cal-cium sulphate CaSO4, and quartz SiO2. The ammonium sulphate is the main component of the fouling deposits. It acts as an adhesive and makes an important contribution to the deposition. The analysis shows that the ammonia slip from denitrification system and the unreasonable temperature setting are the main reasons for fouling deposition. It is suggested that the high concentration of am-monium slip at denitrification system and the rapid condensation of the sulphuric acid mist at heat exchanger should be paid more attention in coal-fired power plants.
KEYWORDS
PAPER SUBMITTED: 2020-03-11
PAPER REVISED: 2020-03-27
PAPER ACCEPTED: 2020-04-15
PUBLISHED ONLINE: 2020-09-26
THERMAL SCIENCE YEAR
2020, VOLUME
24, ISSUE
Issue 6, PAGES [3477 - 3488]
- Wang, G., et al., Persistent sulfate formation from London Fog to Chinese haze, Proceedings of the National Academy of Sciences of The United States of America, 48. (2016), 113, pp. 13630-13635
- Fu, H.,J. Chen, Formation, features and controlling strategies of severe haze-fog pollutions in China, Science of the Total Environment, 578. (2016), pp. 121-138
- Zhao, S.L., et al., Migration and emission characteristics of trace elements in a 660 MW coal-fired power plant of China, Energy & Fuels, 30. (2016), 7, pp. 5937-5944
- Andreas, B., Enhancing ESP Efficiency for High Resistivity Fly Ash by Reducing the Flue Gas Temperature. Springer Berlin Heidelberg, 2009.
- Chen, T.M., et al., An efficient wet electrostatic precipitator for removing nanoparticles, submicron and micron-sized particles, Separation & Purification Technology, 136. (2014), 136, pp. 27-35
- Zhu, J., et al., Effects of high-voltage power sources on fine particle collection efficiency with an industrial electrostatic precipitator, Journal of Electrostatics, 70. (2012), 3, pp. 285-291
- Chen, Y., et al., Study on ultra-low emission reform scheme of 1000 MW coal fired unit, Environmental Engineering, 33. (2012), S1, pp. 1026-1029
- Zhao, Y.C., et al., Status of ultra-low emission technology in coal-fired power plant, Journal of China Coal Society, 40. (2015), 11, pp. 2629-2640
- Srivastava, R.K., et al., Nitrogen oxides emission control options for coal-fired electric utility boilers, Air Repair, 55. (2005), 9, pp. 1367-1388
- Ma, Z.Z., et al., Characteristics of NOx emission from Chinese coal-fired power plants equipped with new technologies, Atmospheric Environment, 131. (2016), pp. 164-170
- Hans, J.H., et al., SCR Design issues in reduction of NOx emissions from thermal power plants, Frederikssund: Haldor Topsoe Inc. (2007),
- Shi, Y.J., et al., Formation and decomposition of NH4HSO4 during selective catalytic reduction of NO with NH3 over V2O5-WO3/TiO2 catalysts, Fuel Processing Technology, 150. (2016), pp. 141-147
- Jimenez, A., Simulation of an air preheater model, Memorandum. Palo Alto (CA): EPRI. (2007),
- Menasha, J., et al., Ammonium bisulfate formation temperature in a bench-scale single-channel air preheater, Fuel, 90. (2011), 7, pp. 2445-2453
- Chothani, C., Ammonium Bisulfate (ABS) Measurement for SCR NOx Control and Air Heater Protection, Carnegie: Breen Energy Solution. (2008), pp. 1-13
- Sui, Z.F., et al., Fine particulate matter emission and size distribution characteristics in an ultra-low emission power plant, Fuel, 185. (2016), pp. 863-871
- Grass, N., et al., Application of different types of high-voltage supplies on industrial electrostatic precipitators, IEEE Transactions on Industry Applications, 40. (2004), 6, pp. 1513-1520
- Peng, W., et al., Kinetics Analysis on Mixing Calcination Process of Fly Ash and Ammonium Sulfate, Chinese Journal of Chemical Engineering, 22. (2014), 9, pp. 1027-1032
- Huy, D.H., Development of Simultaneous Measurement Method of Gaseous Ammonia and Fine Particulate Ammonium and Study on Their Behaviors in Urban Atmosphere, 2016.
