Research On Numerical Simulation Of Tiny Oil Ignite Biomass And Low Volatile Coal

The energy distribution in Our country shows that the largest consumption is coal, and the oil accounts for a small part. The backwardness in coal clean combustion technology is an important reason, what has caused serious environmental pollution problems. The oil has become an important material affects and restricts the all-round development of our country because the oil expending rely on imports. The most coal-fired power plants need consuming much oil each boiler ignition. The combustion of low volatile coal released nitric oxide cause severe environmental pollution. Social and economic rapid development has consumed a lot of resources, environment has paid a heavy price for it. How to improve electric power products unit energy consumption, reducing emissions is the chief problem of thermal power industry must be considered. Our country agricultural product have a wide variety, waste plant straw and leftover bits of materials is a huge waste. Biomass resources in China is abundant, increasing its utilization can reduce the pressure on all aspects and bring benefits to our society The technology oftiny oil ignite biomass and low volatile pulverized coal can not only improve the biomass energy utilization but also reduce the oil consumption and the emissions of nitric oxide. Studying the technology has important significance.The method of numerical simulation is employed in this paper to investigate the combustion characteristic of biomass and low volatile pulverized coal bytiny oil ignition. This thesis choices three kinds biomass which are poplar, soybean straw, cotton. And four kinds of important factors which influence the ignition of biomass and low volatile pulverized coal are analyze such as the velocity of fuel air, the type of biomass, the particle size of fuel and the blending ratio of coal and biomass. Selecting the three equations model which are mass conservation, momentum conservation and energy conservation, standard k-ε turbulence double-equation model, P-1 radiation model, equilibrium mixture fraction/PDF model, pollutant formation model, etc. to build complete burning model artifacts. And then the model be meshed, set up the boundary conditions and parameters calculation to simulate. On the analysis of the internal temperature field and the distribution of the material composition intiny oil ignition burner, get the following conclusion. The best burning effectiveness with low volatile pulverized coal was poplar which has the highest content of volatile, the higher the volatile content, the more combustible gases come from mixed fuel pyrolysis in the combustion process, the more conducive to the lighting and stable combustion of coke. The blending ratio of coal and biomass was 10%-15% has the best burning.The less the ratio, the worse the effect. The mixed fuel will has a low calorific value as the biomass add. The combustion heat is not enough to maintaining high flame temperature, and maybe lead the ignition to failed. To maintain the best ignition effect is the best mixed fuel particle size. Whereas the burner outlet temperature showed a trend of rise as the hybrid particle size increases when the fuel particle size is less than the critical value. The critical hybrid particle size was between 96-120tinyns in the simulated condition in this paper. Because of the large resistance, the solid phased particles of fuel gas in burner maybe sedimentation, and attached to the burner wall surface, scour by high temperature flame if the velocity of fuel air is too small. At the same time, low volatile pulverized coal coking, possibly clog the burner internal space. If the velocity of fuel air is too large, it would cause its heating time too short to incomplete combustion. And at the same time strengthened the convection heat transfer, sped up the heat loss which caused delay of the volatile in the mixed fuel and coke combustion. All the factors made fire distance increases and the combustion instability improves. The temperature of biomass volatility analyze is much lower than low volatile coal whentiny oil lighting the mixed fuel. The biomass release groups such as CH2、CH after absorbing heat quickly from flue gas flow and wall radiation. Then the groups react with nitrogen in the air and coal which can effectively reduce the rapid type and fuel type NO emissions.