Analysis Of Combustion Mechanism And Influencing Factors Of Alcohol-based Fuel In Furnace

With the background of the national dual carbon policy and people’s pursuit of green development,alcohol-based fuels have gradually entered people’s vision as a renewable clean energy.The study of alcohol-based fuels is of great significance for enhancing the sustainable development of energy.This paper relies on the model parameters of alcohol-based combustion boiler and some fuel properties provided by Heilongjiang Institute of Energy and Environment.The paper focus on the physical and chemical properties of alcohol-based fuel,the methanol fuel combustion after blending water is studied.The combustion conditions inside the furnace and the mass fraction of the products in the furnace were studied by using numerical simulation technology,under different water-blended ratios for different influencing factors,and the distribution of pollutants at the tail of the furnace was discussed.Under the determined water-blended ratios,the effect of preheating temperature on fuel atomization and the distribution of effect on combustion and the distribution of products in furnace are discussed.Based on the chemical combustion reaction kinetics,a diffusion flame-Non-Premixed Combustion suitable for the combustion of fuel and oxygen was selected to simulate and analyze the methanol combustion mechanism under different water-blended ratios in the horizontal boiler furnace.The temperature and fuel consumption inside the furnace under nine operating conditions with a uniform distribution of water-blended ratios from 0%to 20%were studied in detail.The results show that the fuel has different effects on the temperature distribution in the furnace under different water-blended ratios.With the increase of water-blended ratios,the temperature in the furnace decreases first,then increases and finally continues to decrease.There is a peak temperature.When the water-blended ratio is 10%,the reaction in the furnace is the most intense,and the highest temperature can reach 1930K,and the temperature distribution in the furnace is more uniform,which is 827K.The increase of water content also affects the combustion stability in the furnace.It is found that when water-blended ratio is 10%,the combustion effect and the combustion stability in the furnace is the best.Under this water-blended ratio,due to the good combustion stability in the furnace,the CO and NO_x emissions are also at a low level,which can effectively reduce pollutant emissions.Based on the simulation results of alcohol-based fuel with water-blended ratio of10%,the factors affecting the combustion in the furnace are further studied.The temperature inside the furnace,the mass fraction of the products,the atomization effect of the droplets and the change of the furnace at different times were studied in detail when the oxidant preheating temperature was different.The results show that the increase of preheating temperature of the oxidant has a positive effect on the combustion in the furnace.With the increase of preheating temperature,the ignition process of fuel is advanced and the flame combustion is more sufficient.When the preheating temperature of the oxidant is increased to 500K,the average temperature in the furnace reaches the highest,which is 2073K,and no longer continues to rise with the increase of the preheating temperature.At this preheating temperature,the concentration of CO and CO₂ also reached a stable state,indicating that the furnace internal reaction is sufficient,chemical reaction reached equilibrium.With the increase of preheating temperature,the NO_x production increases slightly,but when the preheating temperature reaches 500K,the NO_x production is stable.It shows that at this preheating temperature,the reaction in the furnace is stable,the combustion efficiency is high,and the economy is good.