Effects of operating conditions and fuel properties on emission performance and combustion efficiency of a swirling fluidized-bed combustor fired with a biomass fuel

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• 作者：Vladimir I. Kuprianov^a ; ^{ivlaanov@siit.tu.ac.th} ; Rachadaporn Kaewklum^b ; Songpol Chakritthakul^a
• 关键词：Swirling fluidized bed ; Rice husk ; Temperature ; Gas concentrations ; Combustion efficiency
• 刊名：Energy
• 出版年：2011
• 出版时间：April 2011
• 年：2011
• 卷：36
• 期：4
• 页码：2038-2048
• 全文大小：746 K

文摘

This work reports an experimental study on firing 80 kg/h rice husk in a swirling fluidized-bed combustor (SFBC) using an annular air distributor as the swirl generator. Two NO_x emission control techniques were investigated in this work: (1) air staging of the combustion process, and (2) firing rice husk as moisturized fuel. In the first test series for the air-staged combustion, CO, NO and C_xH_y emissions and combustion efficiency were determined for burning “as-received” rice husk at fixed excess air of 40 % , while secondary-to-primary air ratio (SA/PA) was ranged from 0.26 to 0.75. The effects of SA/PA on CO and NO emissions from the combustor were found to be quite weak, whereas C_xH_y emissions exhibited an apparent influence of air staging. In the second test series, rice husks with the fuel-moisture content of 8.4 % to 35 % were fired at excess air varied from 20 % to 80 % , while the flow rate of secondary air was fixed. Radial and axial temperature and gas concentration (O₂, CO, NO) profiles in the reactor, as well as CO and NO emissions, are discussed for the selected operating conditions. The temperature and gas concentration profiles for variable fuel quality exhibited significant effects of both fuel-moisture and excess air. As revealed by experimental results, the emission of NO from this SFBC can be substantially reduced through moisturizing rice husk, while CO is effectively mitigated by injection of secondary air into the bed splash zone, resulting in a rather low emission of CO and high (over 99 % ) combustion efficiency of the combustor for the ranges of operating conditions and fuel properties.