Abstract
During combustion of fossil fuels a large amount of harmful substances are discharged into the atmospheres of cities by industrial heating boiler houses. The most harmful substances among them are nitrogen oxides. The paper presents one of the most effective technological solutions for suppressing nitrogen oxides; it is arrangement of circulation process with additional mounting of the nozzle directed into the bottom of the ash hopper. When brown high-moisture coals are burnt in the medium power boilers, generally fuel nitrogen oxides are produced. It is possible to reduce their production by two ways: lowering the temperature in the core of the torch or decreasing the excess-air factor in the boiler furnace. Proposed solution includes the arrangement of burning process with additional nozzle installed in the lower part of the ash hopper. Air supply from these nozzles creates vortex involving large unburned fuel particles in multiple circulations. Thereby time of their staying in the combustion zone is prolonging. The findings describe the results of the proposed solution; and recommendations for the use of this technological method are given for other boilers.
Highlights
Coal-fired steam and hot water boilers are the most common variants for heat sources of social and industrial facilities
According to results of the boiler efficiency tests it has been found that the implementation of proposed arrangement of the burning process with additional mounting of the nozzle directed into the bottom of the ash hopper decreased the concentration of nitrogen oxides by 25% (Table 1). This can be explained by the formation of combustion zones in the furnace chamber characterized by the excess of air and temperature
Implementation of the circulation process arrangement allows to reduce the emissions of nitrogen oxides by 110 mg/m3; unburned carbon loss decreases by 0.04%
Summary
Coal-fired steam and hot water boilers are the most common variants for heat sources of social and industrial facilities. The main problem of using such equipment is nitrogen oxides emissions to the atmosphere generated during coal combustion [1]. Technologies of solid fuel staged combustion with air portion supply above the main burners are known to allow reducing the concentration of nitrogen oxides by 40-50% [2-8]. Implementing these technologies the gas temperature at the outlet of the furnace increases. It is not acceptable for boilers burning brown high-moisture coal, because it increases the contamination of the heating surfaces. The purpose of this work is to investigate the possibility to arrange the combustion process focused on reducing nitrogen oxide emissions without reduction of boiler efficiency
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
