Research On Low Heat Value Fuel Ignition And Combustion Enhancement

The annual output of low calorific value fuel in China is very large.In 2017,The gas output reached 1,062.69 billion cubic meters,a cumulative increase of 3.9%.Blast furnace gas is the associated gas produced in steel production.Due to technical immaturity,the total amount of blast furnace gas wasted is equivalent to 9 million tons of standard coal.It is a huge waste of energy.Moreover,the blast furnace gas is difficult to ignite in the gas turbine due to the low calorific value,the combustion stability is poor,and the flame is easily extinguished.Ignitionassisted combustion technology of plasma has the advantages of short ignition delay time,high ignition energy and activation combustion,so it has the potential to solve the above-mentioned low heating value gas energy waste.In view of the problems of low calorific value fuel ignition and slow flame propagation speed,this paper studies the ignited combustion characteristics of low calorific value fuel by experiments and numerical simulations.The main research contents are as follows:(1)Modeling the kinetic model by solving the Boltzmann equation with the collision surface information.The influence of the parameters of carbon monoxide content,stoichiometric ratio and reaction temperature on the ignition delay time was calculated by using the plasma PSR module of CHEMKIN software.Finally,a sensitivity analysis was performed for temperature and OH to analyze the reaction that had the greatest influence on temperature and ignition delay time.(2)Numerical simulation of plasma-assisted low calorific value fuel based on real combustion chamber model using FLUENT software.The Realizable k-? turbulence model and the eddy-dissipative combustion model were used to numerically simulate the important parameters of the combustion chamber such as the meridional temperature distribution,the meridional velocity distribution,the flame length and the combustion efficiency.(3)The experimental method was used to optically measure the discharge characteristics of the low calorific value fuel igniter in the air and the ignition test of the low calorific value fuel was carried out to obtain the low calorific value fuel ignition boundary.(4)Simplify the complex structure of the combustion chamber head,Simulation of low calorific value fuel ignition process using FLUENT software,and explore the effect of plasma on the ignition characteristics of low calorific value fuel from three aspects of thermal effect,chemical effect and aerodynamic effect.