Utilization of combustible waste gas as a supplementary fuel in coal-fired boilers

Abstract

Summary A system is proposed to use the combustible waste gas as a supplementary fuel in coal‐fired boilers. The combustion air can be partially or fully substituted by ventilation air methane or diluted combustible waste gases. The recommended volume fraction of combustible waste gas in combustion air is no more than 1.0%. The effect of waste gas introduction on thermodynamic parameters of boiler is evaluated through thermal calculation based on material balance, heat balance, and heat transfer principles. A case study is conducted by referring to a 600 MW supercritical pressure boiler. The results show that no retrofit of boiler is required. The operation of boiler is scarcely influenced, and the original forced and induced draft fans can meet the requirement. With increasing volume fraction of combustible waste gas, the flue gas temperature at the furnace exit decreases monotonically, resulting in an increment of heat absorption in furnace and a decrement of heat transferred in convective heating surfaces. When 1.0% volume fraction of hydrocarbon gas is introduced, the thermal efficiency of boiler is increased by 0.5%, and the coal consumption rate is reduced by 25.4%. The cost analysis of the proposed system is conducted, and break‐even curves are given as references for the utilization of waste gas as a supplementary fuel. The economic velocity of the combustion air is suggested to be 18.2 m s−1.

Fuel Classification based on Flame Characteristics using a Time Series Analysis with Fuzzy Support Vector Machine Algorithm

“…Among these, coal and oil are mainly used. 35,36 In most power generation units, coal, oil, and coal + oil are used as fuels. Oil is used (short time) to start the boiler, as oil has more flammable characteristics than coal.…”

“…In this paper, Macro-Precision, Macro-Recall, and Macro-F-measure 38,44 are used to check the effectiveness of the classification technique. The formulae for calculating the above-mentioned measures are given in Equation 24- (35).…”

“…They are utilized and given as supplementary for coal-fired boilers. 35,36 So, from the literature review, it is understood that the ultimate aim of all researches is to increase the energy conservation, efficiency and performance of power generation and to control the emissions. In the fuel repository, coal is not separated based on quality.…”

A Review of the Numerical Modeling of Pulverized Coal Combustion for High-Efficiency, Low-Emissions (HELE) Power Generation

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Will It Be Possible to Put into Practice the Mitigation of Ventilation Air Methane Emissions? Review on the State-of-the-Art and Emerging Materials and Technologies

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