Experimental Study On Dilution And Diffusion Combustion Of Syngas

Syngas can be gasified by coal,biomass and waste in the gasifier,and then obtained by purification. It is a clean fuel and has broad application prospects. But the synthetic gas component obtained from different raw materials is relatively complex, it's low calorific value and poor combustion stability, which has brought a lot of difficulties to its practical application. For example, NO. emission control is one of the important problems. Adding diluent in gas fuel is an effective method to inhibit NOx formation, but the relevant experimental research needs to be further improved. This article is based on gas fuel dilution combustion technique, in which the axisymmetric laminar diffusion flame in the same direction is taken as an object. The effect of diluent addition on the formation of NO and CO pollutants in syngas / air diffusion flames is investigated using experimental methods.An experimental system for gaseous fuel diffusion combustion was established,through experimental methods to study the emission characteristics and variation of NO and CO in different gas mixtures under different diluent types, dilution ratios and diluent addition conditions. It is found that the flame color of pure syngas burns from shallow to deep, from light yellow to light blue, then from light blue to bright blue with the decrease of H2/CO ratio. Meanwhile the flame becomes strong and high and the width narrows. By measuring the pollutant content in the exhaust gas, it was found that the three kinds of diluents in the experimental all can effectively reduce the generation quantity of NO and CO. Concretely, the emission index of NO increases monotonically with the increase of hydrocarbon ratio, however, the emission index of CO is opposite. The research found that EINO (R) > EINO (Y) is established for those three kinds of dilutions of N2, Ar and CO2 and EIco (Y) > EIco (R) is established for those two kinds of dilutions of N2, CO2.In addition, the change rule of EINO and EIco is different with dilution ratio, diluent type and diluent addition side. The effects of the three kinds of diluents on NO emission reduction are as follows: CO2 > N2 > Ar > pure synthetic gas. That is to say that CO2 works best, N2 takes second place and Ar is worst. But adding either of these three diluents is better than not adding the thinner. Similarly, there exists the relationship for CO: N2 = Ar > CO2 > pure synthetic gas.In this thesis, the diffusion combustion characteristics of syngas under different conditions was investigated and the effects of combustion characteristics of syngas was analyzed in different H2/CO ratio, different diluent type, different dilution ratio and different adding side of diluent. The emission law of NOx and CO during combustion of synthetic gas has been revealed, and an effective method to promote stable combustion of synthetic gas and low pollutant emission has been obtained. The relevant experimental data can provide guidance for the design and optimization of practical combustion equipment and has certain engineering application value.