Experimental Study On Combustion Characteristics Of Inferior Fuel Oil Based On Porous Media

Inferior fuel is the residue of crude oil after refining,mainly heavy oil and residual oil.At present,inferior fuels have problems such as poor combustion stability,low efficiency,and serious environmental pollution during combustion.The co-firing with coal not only aggravates the slagging phenomenon,but also causes secondary pollution of low-burning particulate matter.Therefore,direct and efficient use of inferior fuel combustion can save resources and reduce emissions of burning pollutants.Domestic and foreign scholars have proposed various intensified combustion and emission control technologies.Among them,porous medium combustion technology is one of the current research hotspots.However,there are few reports on the industrial application of oil and gas porous media combustion.This paper has conducted in-depth research on the variation of particulate matter deposition behavior and combustion characteristics in inferior fluel infiltration in porous media.Combined with the current situation of inferior fuel in China,three typical inferior fuel oils were selected and infiltrated in porous media to study the effects of air flow rate,heating rate and material and porosity of porous media on particulate matter deposition.Thermogravimetric analysis was used to study different Combustion characteristics of inferior fuel oil and its infiltration in porous media of different materials;using Coats-Redfem reaction equation,in-depth study of combustion reaction mechanism through kinetic analysis,predicting the difficulty of combustion reaction,infiltration of inferior fuel in porous media Research on combustion provides the necessary basic data and theoretical basis.The results show that the higher the porosity of porous media,the higher the burning rate of inferior fuel,the more thorough the burning;the inferior fuel infiltration in the burning of A12O3 porous media,the burning rate of oil is higher than that in infiltrated in SiC porous media;When the flow rate is small,the incomplete combustion loss is large,the carbon black is not easily burmed,and the combustion is deteriorated;the higher the heating rate,the smaller the burning rate of the oil;In the process of oil combustion alone,Hubei oil has the lowest ignition temperature,followed by Sichuan oil,Ningxia oil has the highest ignition temperature,Hubei oil has the lowest burnout temperature,and Ningxia oil has the highest burnout temperature.With the increase of heating rate,The maximum weight loss rate of the oil in each reaction stage becomes larger,the burnout temperature becomes larger,and the thermal hysteresis is obvious.When the oil is infiltrated in the Al2O3 porous medium and the SiC porous medium,the Ningxia oil and the Hubei oil are volatilized and analyzed.The eombustion section is still in the burnt section of the carbon residue.The strongest peak position is advanced,the half-peak width becomes smaller,the pyrolysis combustion process is shortened,the burnout temperature is advanced,and the strongest peak position and burnout temperature of Sichuan oil are lagging behind.This may be related to the degradation of Sichuan oil in the first stage and the high degree of volatilization.With the increase of heating rate,when the oil is infiltrated in Al2O3 porous medium and SiC porous medium,the ignition temperature is advanced at low heating rate.However,at high heating rates,the ignition temperature is lagging behind;At each heating rate,the activation energy of the slow oxidation stage of Ningxia oil is greater than that of the rapid oxidation stage,indicating that the small molecule organic matter in the Ningxia oil is not volatile at the early stage of the reaction,and it needs to obtain more energy from the environment to complete.The activation energy of oil and Hubei oil in the rapid oxidation stage is higher than that in the slow oxidation stage;as the heating rate increases,the activation energy of the slow oxidation reaction stage of the oil shows an increasing trend,and the rapid oxidation stage The activation energy shows a decreasing trend;when the oil is infiltrated in the SiC porous medium and the Al2O3 porous medium,the activation energy of the slow oxidation stage is reduced except that the Ningxia oil is heated at a temperature of 5℃/min.Under the condition,the activation energy of the slow oxidation stage showed an increasing trend;in the rapid oxidation stage,the activation energy decreased with the addition of porous medium;the oil was infiltrated in the Al2O3 porous medium.In the middle,the activation energy is reduced more in the rapid oxidation stage than in the SiC porous medium.