Co-firing straw and coal in a 150-MWe utility boiler: in situ measurements

A 2-year demonstration program is carried out by the Danish utility I/S Midtkraft at a 150-MWe PF-boiler unit reconstructed for co-firing straw and coal. As a part of the demonstration program, a comprehensive in situ measurement campaign was conducted during the spring of 1996 in collaboration with the Technical University of Denmark. Six sample positions have been established between the upper part of the furnace and the economizer. The campaign included in situ sampling of deposits on water/air-cooled probes, sampling of fly ash, flue gas and gas phase alkali metal compounds, and aerosols as well as temperature measurements. Material balance closures were carried out at all operating conditions. The experimental data was evaluated together with researchers from the Technical University of Denmark and the results were stored in a data base program developed under the CHEC-research program to predict deposition propensities and high temperature corrosion during co-combustion of straw and coal in PF-boilers. Danish full scale results from co-firing straw and coal, the test facility and test program, and the potential theoretical support from the Technical University of Denmark are presented in this paper.

[1]  H. Livbjerg,et al.  The formation of submicron aerosol particles, HCl and SO2 in straw-fired boilers , 1998 .

[2]  P. Walsh,et al.  Deposition of bituminous coal ash on an isolated heat exchanger tube: Effects of coal properties on deposit growth , 1990 .

[3]  John N. Harb,et al.  Fireside corrosion in PC-fired boilers , 1990 .

[4]  G. A Osborn,et al.  Review of sulphur and chlorine retention in coal-fired boiler deposits , 1992 .

[5]  Hans Livbjerg,et al.  Formation of submicron particles from the combustion of straw , 1995 .

[6]  Kim Dam-Johansen,et al.  Trace elements from combustion and gasification of coal—An equilibrium approach , 1994 .

[7]  Lone Aslaug Hansen,et al.  Alkali metals in a coal- and biomass-fired CFBC -- Measurements and thermodynamic modeling , 1995 .

[8]  Hans Livbjerg,et al.  A field study of submicron particles from the combustion of straw , 1996 .

[9]  E. A. Sondreal,et al.  Ash Fouling in the Combustion of Low Rank Western U.S. Coals , 1977 .

[10]  O. Michelsen,et al.  Sequence and systems tract interpretation of the epicontinental Oligocene deposits in the Danish North Sea , 1996, Geological Society, London, Special Publications.

[11]  W. Reid.  External corrosion and deposits : boilers and gas turbines , 1971 .

[12]  S. Bhattacharya,et al.  The properties and thermal effects of ash deposits in coal-fired furnaces , 1993 .

[13]  V. Haanappel,et al.  Corrosion Kinetics of Low- and High-Alloy Steels in Chlorine-Containing Gas Atmospheres , 1992 .

[14]  Ole Hede Larsen,et al.  Slagging and fouling propensity: Full-scale tests at two power stations in western Denmark , 1996 .

[15]  Larry L. Baxter,et al.  Alkali deposits found in biomass power plants: A preliminary investigation of their extent and nature. Volume 1 , 1995 .

[16]  Larry L. Baxter,et al.  Ash deposition during biomass and coal combustion: A mechanistic approach , 1993 .

[17]  Kim Dam-Johansen,et al.  Deposition and high temperature corrosion in a 10 MW straw fired boiler , 1998 .

[18]  T. Tsuneki,et al.  A newly developed polymer to inhibit scale in cooling water systems , 1989 .

[19]  R. Hatt.  Fireside deposits in coal-fired utility boilers , 1990 .