Coal-water Slurry Fuel Combustion Research Articles

Results of Study of Sulfur Oxide Reduction During Combustion of Coal-Water Slurry Fuel Through use of Sulfur Capturing Agents

It is shown that an effective way of burning high sulfur coal is to burn coal-water slurry fuel (CWF) prepared on its basis containing a sulfur capture agent (SCA) entered in the slurry at the stage of preparation. The technique of thermodynamic analysis of chemical reactions during CWF burning has been developed including burning in the presence of SCA. Using the developed calculation program, the optimal temperature conditions have been determined as required for the effective reduction of sulfur oxides in flue gases when using different types of SCA. According to the results of calculating the composition of CWF combustion products when entering various substances in the burner space as SCA it has been determined that magnesite, calcite, and dolomite are the most effective natural minerals. The analysis of calculated and experimental data proves the efficiency of SCA addition as well as validity of the obtained results.

Partitioning behavior of trace elements during pilot-scale combustion of pulverized coal and coal–water slurry fuel

Release pathways for inorganic hazardous air pollutants (IHAPs) from a pilot-scale, down-fired combustor (DFC) when firing pulverized coal (PC) and coal–water slurry fuel (CWSF) were identified and quantified to demonstrate the effect of fuel form on IHAP partitioning, enrichment and emissions. The baghouse capturing efficiency for each element was calculated to determine the effectiveness of IHAP emission control. Most of the IHAPs were enriched in the fly ash and depleted in the bottom ash. Mercury was found to be enriched in the flue gas, and preferentially emitted in the vapor phase. When firing CWSF, more IHAPs were partitioned in the bottom ash than when firing PC. Significant reduction of Hg emissions during CWSF combustion was also observed.

Progress on the Investigation of Coal-Water Slurry Fuel Combustion in a Medium-Speed Diesel Engine: Part 6—In-Cylinder Combustion Photography Studies

In the GE 7FDL single cylinder research diesel engine, in-cylinder high-speed photographic studies were conducted on coal-water slurry (CWS) fuel combustion. Distinct flames of pilot and CWS combustion were noticed. It was proven that the coal fuel burns after piston impingement and secondary atomization. Agglomerated particles will develop when combustion conditions are not favorable. Cylinder pressure data were simultaneously recorded for each film frame. Heat release data can thus be produced for each photo study. Most of the findings of earlier combustion studies on engine performances were confirmed.

A Model of the Enhancement of Combustion of Coal-Water Slurry Fuels Using High-Intensity Acoustic Fields

Combustion of coal-water slurry fuels is simulated in the presence of high-intensity acoustic fields which increases heat and mass transfer from the droplets and particles, and thereby enhances the combustion. The steady-slip velocity and acoustically induced slip velocity are calculated along particle trajectories, giving the augmented Nusselt and Sherwood numbers in the presence of high-intensity acoustic fields compared with no-sound conditions. The paper also presents the water evaporation and char burn-out history for particles with diameters between 90–110 μm exposed to sound pressure levels of 160–170 dB and compares the results to similar cases under no acoustic field. A decrease in the char burn-out length of about 12.1 percent at 160 dB, 18 percent at 165 dB, and 24 percent at 170 dB sound pressure level is obtained compared to the case with no sound for 100-μm particles introduced at centerline.