The Structure Design And Experimental Study On The Domestic Biomass Updraft Gasifier

It is abundant in biomass resource, especially cotton-stalk in Xinjiang, China. However, no reasonable and effective ways to make the best of it's potential so far. Biomass gasification is main mode of utilizing biomass energy, the study on biomass gasification is a complicated systems engineering, gasification performance was affected by many factors. So, to design biomass gasifiers and to do deeper experimental study on them has important meaning, it can provide guiding suggestions for optimizing interior structure of gasifier and techniques for gasification.Based on cotton-stalks, the author design a suit of domestic biomass gasification system, and do some experimental study on it. The main elements and industry components of cotton-stalk were analyzed by 112SERIES mode element analysis apparatus, points of measuring temperature were placed by the method of biomass color illation, air discharge were controlled by rotate speed of fan, the areas where steam supply were controlled by steam valve on steam supply unit, this paper discussed influence rules between air discharge, gasification agent species and reaction temperature, gas quality.The main results of this gasification study are as follows:1. A suit of domestic updraft biomass gasification system was designed, the gasifier includes several-path wind feed device and steam supply unit, two-step purifying device were installed on the system additionally. Tested and calculation results showed that the gasifier have better basal performance and purifying effect than others.2. This paper studies the relationship between reaction temperature, gas quality and air discharge for domestic updraft biomass gasifier. The results of the experiment indicate that,①The effects of air discharge on reaction degree and section state in the gasifier were not salient. Temperature of drying and pyrolysis section had inconspicuous change under different air discharge, combustion and reduction section were sensitive to air discharge contrarily, more air discharge, more temperature fluctuation.②The effects of air discharge on methane(CH4) content were not salient, but the effects of air discharge on hydrogen(H2) and carbon monoxide(CO), especially on carbon monoxide were salient. The carbon monoxide content of gas would reduce if air discharge was high or low extremely. Experimental study showed that the carbon monoxide content was highest as air discharge was 0.55m3·min-1, however, the reverse is change trend of hydrogen and carbon monoxide.3. This paper studies the reaction temperature on domestic updraft biomass gasifier with and without steam supply unit separately. The results of the experiment indicate that, gasification with steam can hoist combustion section temperature ratherish, and also make reduction section temperature reduce, it will be of great benefit to reduction tar content in biomass gas. The test of gasifier performance experiment indicate that it can increase combustible component and improve gas quality when gasifier runs with steam supply unit.