Development And Experimental Research On Household-type Biomass Gasifier

With the fossil resource decreasing and the serious pollution caused by fossil fuel combustion, the biomass energy attracts more and more attention. As a key thermochemical conversion technology of biomass energy, thermal gasification technology is an increasing concern. As the household-type biomass gasification technology has advantages of simple structure, short pipeline, simple operation and inexpensive maintenance, it is prevailing to economic level and organizational structure in China's rural areas. Therefore, the paper chooses household-type biomass gasifier to research and develop, which has the value for guiding its application. The test bench of household-type gasification system is built by ourself. In the base of the preliminary study of gasifier on active duty, the updraft-type gasifier and purification devices are designed by references and experience. Through a combination of trial and theoretical analysis, investigations of major technical performance of the gasifier and domestic gas cooking appliances are carried out.In this paper, the gasifier design applies the patented technologies of central burning and the tail wind. Purification devices are a series of a gas and water separator and dry particulate filter layer. Besides, a device for tar return is designed for the gasifier. Experiments show that, on the gasifier designed, gas heat value increases, gasification efficiency can reach 65 percent or more steadily, and removal of tar works significantly. That resolves some problem in the active-duty gasifier, such as the low heat value and gasification efficiency, high tar content and so on. The design parameters provide a reference for household-type gasifier design.On the self-built biomass gasification platform, the relevant studies for the main technical performance are carried out, including biomass materials, air volume, gasification intensity and other parameters. Removal effectiveness of the purification devices installed and the infection to gasification performance caused by the tar return are also researched. Further, attentions in the process of using gasifier are summed up. The following conclusions are gained: the relevant parameters of biomass raw materials (moisture content, the height of material, types of raw materials) have a significant effect on gasification performance; air volume can immediately and easily control the production of gasifier, and a right range exists; removal of the purification devices installed works significantly; the design for tar return is reasonable, which can improve the quality of gas and gasification.What's more, related performance tests of gas cooking appliances are carried out, including heat load and thermal efficiency, the stability of the flame and the emission of pollutants.Experiments show that, the average heat load maintains between 3.3～3.6 kW; the average thermal efficiency is about 50%; NO_X, SO₂ emissions are both below the standard of low-emission cooking appliances. The experimental datas can provide a reference for related departments to develope the relevant standards.