The Experimental Research And Simulation On The Biomass Semi-Gasifier Based On Ansys CFX

Due to the energy crisis becoming worse day by day, the price of traditional energy being used more commonly in rural region such as coal, natural gas was rising, so the cost of living energy greatly increased. In order to deal with the daily cooking energy for most people in rural, and reduce the environmental problems induced by disorder piling and burning the large amount of biomass waste, we designed a high efficiency semi-gasifier furnace Based on the traditional stove for those biomass, which was largely produced from people's cultivation, including crop straw and forestry waste. The main content and related results on this paper was listed as following:1) The fuel characteristic differences between biomass and coal were great. Because of the high ratio of oxygen, the heat value of biomass was lower than coal. The combustion process of biomass was divided into four stages:preheating and dry, volatiles releasing and pyrolysis, burning of volatiles and combustion of fixed carbon. Accelerating the semi-gasify process was benefited for improving the combustion efficiency of biomass. The pyrolysis and gasification process was influenced by the size of fuel, heating rate, temperature and residence time of gas.2) Based on the traditional stove, we designed a biomass semi-gasifier under the design principle of industry stove. With the calculation of biomass combustion, the main dimension parameters were determined, and then draw the design papers. At last we manufactured the appliance.3) With the method of GB4364-84——Testing method for the heat characteristics of firewood stoves, we tested the heat efficiency index of biomass gasifier. The results showed that the total efficiency of the furnace was up to 36.53%, and there is a good effectiveness and the implementation value is high. Meanwhile the effects of main inlet, secondary inlet, fuel amount and chimney heights on heat efficiency index was tested. Under the orthogonal test, the interaction between those factors on heat efficiency index was also considered, and it showed that only the heat efficiency index was greatly influenced by the interaction of main inlet with fuel amount.4) The simulation of biomass semi-gasifier airflow field was implied by the software of ANSYS CFX. Compared with different chimney height, structure of chamber and secondary inlet, we studied those influence on airflow field, which provided the valuable information for improving the heat efficiency of biomass semi-gasifier.5) Some recommendations were made for later research on biomass semi-gasifier, also proposal and prospect on improving the heat efficiency were put forward.Under the conclusion of the research, the biomass semi-gasifier has a wider adaptability on biomass materials, and the total heat efficiency is high, so as the better application values. Currently the research on the biomass semi-gasifier in our country is relatively small, so there is a large space for theory and application research.