Researchers will run experiments and simulations to understand how new technology can help reduce pollution while maximizing combustion efficiency
Coal-fired power plants have long been installed to meet the global demand for electricity generation. Needless to say, there are environmental and human health concerns that must be addressed on this front. Despite ongoing efforts to transition to renewable energy sources, coal-fired power plants may not yet be obsolete. Against this backdrop, explore ways to improve the efficiency of these coal-fired boilers while reducing their negative environmental impacts, including greenhouse gas emissions, acid rain, photochemical smog production, and human health. it is appropriate to
For this reason, various combustion methods have been proposed, such as air multi-stage combustion and swirling flow. However, the effectiveness of these technologies in mitigating pollutant emissions while maximizing burnout performance remains unknown.In a recent study that will now be available online on December 31, 2022 and will be published in Volume 268, Issue 1 of the journal energy On April 1, 2023, an international team of researchers led by Professor Gyungmin Choi of Busan National University, South Korea, analyzed the effectiveness of a combination of vortex and air staging in improving combustion performance and reducing pollution. “The exhaust pipe vortex (ETV) structure associated with swirling flow improves flame stability and combustion performance, but has the disadvantage of generating a large amount of NO.X emissions. In contrast, air staging technology creates a fuel-rich environment in the primary combustion zone, which has a positive effect on NO.X It reduces, but it has a negative impact on combustion performance. “ explains Professor Choi. “Thus, the right combination of these two technologies and their application in practice could have a synergistic effect in reducing air pollutant emissions and improving combustion performance.”
Therefore, the team used both simulations and experiments to investigate the combined effects of various swirl configurations and air staging within 16 kW.th Modified a down-fire pulverized coal boiler. The coal boiler consisted of he three sections of swivel burner, boiler and exhaust pipe. In the case of staged combustion, the staged air is split into two sides and injected tangentially into the boiler. Liquefied petroleum (LPG) gas was used for preheating and flame stabilization. The air and LPG flows were adjusted stepwise and the temperature was measured using thermocouples for each setting. Additionally, the amount of gas phase species was measured using a multi-gas analyzer.
Two vortex configurations, co-swirl flame and counter-swirl flame, were evaluated for air staging to understand which is more beneficial in terms of reducing pollutant emissions. For co-swirl burners, where air and fuel circulate in the same sense, the coal particles were evenly distributed due to the formation of an internal circulation zone and ETV, two important features for optimizing the design of coal combustion . boiler.
Additionally, the team observed a uniform combustion zone in a co-rotating configuration. This ensured complete combustion of the fuel and reduced gas species emissions. In addition, the conversion of chemical energy to thermal energy was promoted, improving combustion efficiency.In contrast, the counter-swirl burner showed uneven coal particle distribution, uneven combustion and increased NOX This suggests that the co-rotating configuration is the better option. Additionally, the team showed that air staging technology reduced environmental costs from $0.003 to $0.015 per day.
Overall, the insights from this study could prove highly valuable in solving the environmental problems and health hazards associated with coal-fired power plants. “We have identified and studied the structure and flame of the ETV for the first time, and continue our research and efforts to exploit it in combustion-based industries.” To conclude the optimistic Professor Choi.
Original: Researchers at Busan National University are investigating the combined effects of two combustion technologies on coal-fired boiler emissions
Than: Pusan National University
