Heat Transfer Simulation And Experimental Research On Household Biomass Gasification Stove

As people's living standard is increasing in rural areas, high quality energy is in great demand and energy supply faces shortage problem. As a key thermochemical conversion technology of biomass, which can make the biomass into high quality can gas thus receiving more and more attention. As the household-type biomass energy gasification technology has advantages of simple structure, simple operation and inexpensive maintenance, it is suitable for promotion and employment in our rural areas. Therefore the paper chooses household-type biomass gasifier to research and develop which has the value for guiding its application.On the self-built biomass gasification platform,the relevant studies for the main technical performance are carried out.First, take a series of experiments about corncob) which include measuring its heat value, proximate analysis and ash melting experiments,which shows the corncob has the pecfectcharacteristics of pyrolysis and gasification. Second, to study the gasification agent flow influence on the performance of the gasification, through the experiments of gasifier obtained from the running time, output power. When the primary air is 3.5m3/h, the stove has the highest thermal efficiency 31.4% and the longer running time, when the primary air is 4.5m3h, the stove has the largest average power which is 6.7kW. Excess air coefficient of the combustion process of combustion influence. When excess air coefficient is 1.3, combustion is better, means high flame temperature and less carbon monoxide in flue gas.Household-type gasifier is so small in size and heat exchange shortage that lead to exhaust temperature was too high, so reinforce heat transfer technology to improve thermal, reduce the weight and volume of the gasifier.Firstly,using numerical calculation software FLUENT simulate the heat exchange device.The obtained numerical results almost coincide with the experimental results, which verify the reliability of numerical method.Firstly,using orthogonal test method and establish 16 finned improved heat transfer models, to analysis the fin spacing, fin height and fin thickness three factors on the influence of heat transfer and resistance. Conclusion shows that the thicknesses of fin thick effect the heat transfer most. Get a set of relatively optimal parameters such as fin spacing 4mm, fin height 12mm and fin thickness 1.2mm.Thirdly,simulate a heat transfer device with twisted tape, the twist ratio is 1.11,2.23, 4.44,6.67. The results showed that the lower twist ratio with stronger turbulence, and higher heat transfer coefficient, the resistance also larger. Considering the stove using conditions, the twisted tape's twist ratio is set to 2.23. Comparative analysis these two improved heat transfer device, finally choose the fin improved heat transfer device.This paper research work has certain reference value for this stove to use and to design a new heat transfer device.