Experimental Research And Analyse On Biomass Gasification And Biogas Combustion

Gasifier is a core device of current centralized heating or cooking gas supply via biomass gasification. Based on the characteristics of various gasifiers, downdraft fixed-bed type is selected as the final design scheme. Design and research to the gasifier are presented referring to theories of gas combustion, heat transfer and fluid dynamics. Adaptability of raw materials, air volume and gasification efficiency to the gasifier was carried out experimentally. The results show the gasifier can be operated with good adaptability, high efficiency, low tar content and high gas quality.Development of high-power combustor using biomass-derived gas plays an important role in industrializing application of central heating in rural districts. Biomass-derived gas and natural gas are not interchangeable based on the analysis results using theory of interchangeability,and developing powerful combustion device applicable for biomass-derived gas is therefore necessary. The type of low pressure injected atmospheric burner, which can burn low pressure gas and exihit strong adaptability for various gases, is selected as the design scheme. Respecting to the combustion characteristics of relative burners, properties of biomass-derived gas and the stability of its flame are specifically considered during the design.Numerical simulation and experimental research are conducted following the designed burner. FLUENT software is used to analyze working conditions of the main body of the burner. The simulation of combustion displays the combustion temperature of approx.1000℃, an obvious steady effect of chamber to the flame and extremely low NOx content. In order to justify the structure of burner, experimental research was implemented, including the effects of primary air coefficient, pressure fluctuation and fluid volume rate to the burner. The results illustrate that the design of each part is under our expectation, and a good accordance is foreseen between results of experiment and simulation.Heat-conditon experiment was done from working condition, combustion efficiency and NOx content, and the results show combustion efficiency was lower without secondary air given, and NOx content reached to the exhaust standard of American.