| Energy plays an important role in economic development and social progress.With the rapid growth of the national economy,the consumption of energy is also increasing,and the haze problem is becoming more and more serious.In order to alleviate the environmental pollution caused by coal and the shortage of natural gas,a regenerative biomass gasification combustion system was designed in this sdudy.By combining the up-draft biomass gasification technology with high temperature air combustion technology,biomass can be gasified into low calorific value combustible gas,which is combusted directly with high temperature air.It does not need to purify the combustible gas from biomass gasification or carry out oxygen-enriched combustion,thus solving the problem that low calorific value gasifiable combustible gas can not be fully utilized.The system consists of an upper suction biomass gasifier,a gas modifier,a regenerative burner,a small boiler,a four-way reversing valve for high and low temperature air/flue gas,and a regenerative device.Numerical simulation and experimental methods were used to study the temperature distribution,NOx emission and concentration distribution in the burner in this study.In the part of numerical simulation,the high temperature air combustion is simulated,and the effects of temperature of combustion-supporting air,oxygen concentration on temperature field distribution in the furnace and NOx emission from flue gas at the tail of the system were emphatically studied.The experimental part is divided into two parts:cold state experiment and hot state experiment.The cold state experiment is to verify the rationality of the system design by observing the experimental phenomena,measuring and analyzing the pressure distribution of each part of the system.According to the results of cold test,the shortcomings of main equipment or links such as four-way valve were pointed out,and the design of the whole system was finally improved according to the improvement measures proposed.The temperature distribution in the regenerative biomass gasification combustion experimental system and the emission of pollutants in the tail gas of the system were studied in the hot test,and the overall thermal efficiency and the optimum air coefficient of the regenerative biomass gasification combustion system were calculated.The results of numerical simulation,experiment and comparison of the two results show that the simulation calculation of high temperature air combustion process in this study is accurate,and the regenerative biomass gasification combustion system designed is reasonable and feasible. |
PDF Full Text Request