Study On Combustion Characteristics Of Premixed Gas In Perforated Particles Accumulation Layer

This paper starts with the limitation of porous media material itself in porous media combustion technology,including the thermal shock resistance of the ceramic foam is poor and the small porosity of particle packing structure.A perforated particle accumulation structure is proposed.To explore whether this structure can overcome the above shortcomings and its own combustion characteristics,the following three aspects of perforated particle accumulation structure are studied:1)Physical properties;2)Thermal shock research;3)Study on combustion characteristics.In terms of physical propertes,the porosity and resistance characteristics of six kinds of materials were studied,The porosity of these materials is between 0.60 to 0.70,larger than the traditional particle accumulation structure.On the resistance characteristic of the accumulation layer,by comparing with the classical formula,we analyze the deviation of local resistance.Finally get the formula:?P =(+ B)×(+ ?L).This formula can accurately predict the flow resistance characteristics of gas in the particle accumulation layer.In terms of thermal shock,the water quenching method was used to compare the thermal shock resistance of single-hole ball,honeycomb ceramic particles and traditional foam ceramics.The results show that in terms of thermal shock,the single hole ball is the best,the honeycomb ceramic particle is the second,and the foam ceramic is the worst.In the combustion test.Firstly,a comparison is made between the two types of structures,single-hole ball and honeycomb ceramic.We find that when the flame moved upstream,flame in the honeycomb ceramic particle accumulation layer has a faster speed.Flame moving direction changed,the effect of porosity on the flame velocity is just the opposite.In the same material for flame movement test,flame in the process of moving upstream,the bigger the equivalence ratio is,the faster the flame moves.In addition,the combustion properties of the two materials are compared.It is found that the single-hole pellet is more suitable for the free porous medium layer,both in flame stability and flame temperature.Secondly,The combustion characteristics of the premixed flame in the stacking layer of single-hole pellet with different specifications were explored.When the flame moved upstream,the bigger the porosity of the accumulation structure is,the faster the flame moves.When the flame is stably combusted in the single-hole ball accumulation layer,with the decrease of the bulk structure porosity and the reduction of the combustion equivalent ratio,the flame stability position will move downstream.The stable combustion test was organized in the perforated particle accumulation layer.,The results show that the discharge of pollutants between different stacked structures was not only related to the temperature,but also to the structure of the accumulation layer.Large ball with big hole accumulation layer has advantages in pollutant discharge.Finally,the uniformity of single-hole ball was studied.The results of different stacking tests of two kinds of single-hole ball(layered accumulation and mixed accumulation with Large ball with big hole and small hole)show that in terms of the combustion stability and emissions,layered accumulation structure to be better.