Research On Design And Process Optimization Of Biomass High Temperature Oxidation Furnace

The Controlled Ecological Life Support System?CELSS?is one of the key technologies for establishing an alien planet base.The solid waste in the CELSS needs to be treated safely and stably,releasing elements such as carbon,hydrogen and oxygen to achieve the closed circulation of the material flow in the system and improve the system closure.This topic uses high-temperature oxidation technology to treat the inedible parts of plants in CELSS.The numerical simulation method was used to optimize the geometry of the high-temperature oxidation furnace,and the experiment of high-temperature oxidation treatment of wheat straw and soybean straw and the optimization of the process parameters were carried out using this furnace model.First,FLUENT software was used to simulate the effects of different furnace heights,aspect ratios,and feed angles on the high-temperature oxidation of biomass.In the case of ensuring that the materials are fully burned,the goal is to achieve a small size,light weight,and low energy consumption.By analyzing the movement trajectory of the biomass particles in the furnace and the temperature field distribution in the furnace,the optimized size parameters of the furnace shape are:furnace height 650 mm,diameter 54 mm,feed angle 15°?angle with horizontal direction?.Then,a high-temperature oxidation furnace was made with this optimized size,and high-temperature oxidation experiments of wheat and soybean straw were performed.Adjust the process parameters such as the air intake rate and furnace temperature,and measure the concentrations of CO,NO,and NO₂ in high-temperature oxidation tail gas under various operating conditions.The thermal ash reduction rate,morphology,and composition of the residual ash after the high-temperature oxidation of biomass were characterized.The concentrations of tail gas components and ash content of wheat straw and soybean straw under different process parameters were compared and analyzed,and the influence of process parameters?intake rate,furnace temperature?on the concentration of high-temperature oxidation tail gas and the properties of ash was investigated.The concentration of CO in high-temperature oxidation tail gas first decreases and then rises with the increase of intake air velocity,and gradually decreases with the increase of furnace temperature.The concentration of NO in the exhaust gas increases first and then decreases with the increase of the intake air velocity,and gradually increases with the increase of the furnace temperature.The concentration of NO₂ in the exhaust gas gradually increases with the increase of the intake air velocity and gradually decreases with the increase of the furnace temperature.According to the rule,the suitable process parameters for the high temperature oxidation treatment of wheat straw in this furnace type are:when the feed rate is 3 g/min,the air intake rate is 15-20 L/min,and the furnace temperature is600-650°C.The combustion characteristics of different types of biomass?wheat straw and soybean straw?were also compared and analyzed.Among them,the CO and NOx content in wheat straw high temperature oxidation tail gas was lower than that of soybean straw,while the wheat straw ash heat shock reduction rate was higher than soybean straw ash content,and it is prone to agglomeration and slagging.