Gasification Simulation And Experiment Study Of Sawdust Particle Regenerator

Biomass energy has a very broad application prospects because of its abundant reserves and cleanliness.Biomass gasification technology has been vigorously developed in many related utilization technologies due to its high energy utilization rate and wide application range.Its industrial application has become the research focus of scholars at home and abroad.Based on the project of National Science and Technology Support Program:Integration and Demonstration of Industrial Application Technology for Preparing High Quality Gas by New Mobile Fixed Bed（Project No.2015BAD21B05）,an environmentally friendly regenerative high temperature gasification system was designed and built independently,and related experiments and simulation studies were carried out.The gasification law of sawdust under different reaction temperatures and equivalence ratios in air was studied on the experimental bench.The experimental results show that the reaction temperature is the most important factor affecting the gasification effect.The increase of temperature helps sawdust to fully precipitate volatile matter and deepens the cracking degree of macromolecular hydrocarbons,which improves the gas calorific value,gasification efficiency of the products and rate and carbon conversion rate;Appropriate increase of Equivalent Ratio（ER）is helpful to the formation of CH₄ and thus to the overall calorific value,but too high or too low ER value will cause the decline of product quality.When the reaction temperature is 1035 C and ER value is 0.3,the gasification effect is the best.At this time,the gas calorific value of the product reaches the maximum of 5.41 MJ/m³,and the carbon conversion and gasification efficiency are48.23%and 52.14%,respectively.In this paper,Ansys Fluent 15.0 software is used to select a single regenerative tube in the furnace as the research object.The heat storage and sawdust gasification process in the tube are simulated and studied respectively.The experimental data are compared with the simulation results.The overall error is less than 20%.The simulation results show that the established model is reasonable.After the heat transfer between the flue gas and the furnace is balanced in the heat storage process of the device,the tube The temperature distribution on the inner surface of the wall has a non-linear relationship with the height of the pipeline as a whole.The simulation results show that the gasification process of sawdust in the furnace is similar to that in the downdraft fixed bed,and because of the initial horizontal velocity of the raw material,it will collide with the pipe wall after entering the tube and form a local reflux in the inlet section under the action of pressure difference.Finally,the results of sawdust vapor gasification in the range of 0.6-1.2 S/B at T=1035 C are predicted by the established gasification model.The prediction results show that the proportion of H₂ and H₂/CO in the gas can be effectively increased by introducing appropriate amount of water vapor,but the excessive water vapor not only increases the cost,but also causes quality degradation.When S/B=1.0,there is a maximum calorific value of 11.90 MJ/m³,which also provides some theoretical reference for follow-up related experiment and industrial application.