Study On Lean Burn Characteristics Of Mixed Fuel With Butanol Under Different Blending Ratio

Because of the development of automobile industry in our country and the improvement of our life level, the quantity of cars in china is increasing, so the demand of automobile fuel is bigger and bigger. So it cause the car energy tension, city environment problems and other issues. To alleviate these problems, on the one hand, we need to find new automotive alternative fuels, on the other hand, we need to improve the technology of engine.In this paper, in order to improve the characteristic of combustion of motor fuel, analyzes the advantages and defects of butanol and hydrogen that as the alternative fuel. Then comprehensive the advantages of two kinds of fuel. Analysis the characteristics of butanol mixed with hydrogen when it burn in the constant volume combustion bomb.First, determined the boundary conditions of the combustion test and expounded the method of the combustion test. Simplified the the constant volume combustion, Then according to the model established the three-dimensional model by the software of CATIA. The three-dimensional network to simulate of the constant volume combustion bomb was divided by AVL Fire software. Compared with the experimental data and simulation data, Then verificated the correctness of simulation data.Then, select the initial pressure of 0.8 MPa and 1.2 MPa; The initial temperature of 180℃ and 210℃;excess air coefficient is: 1.0, 1.4, 1.8, 1.4; The proportion of butanol mixed with hydrogen is 5%, 10%, 15%, 20% as the boundary conditions of this research. Compared the combustion characteristic of six kinds of fuel that butanol, gasoline and butanol mixed with hydrogen 5%, 10%, 15%, 20% Under the same boundary conditions. Research results showed that with the increase of hydrogen proportions the pressure of combustion is increased and the burning time become shorter. With the increase of excess air coefficient the burning become slower, the pressure and heat release become lower. The effects of initial pressure on burning temperature is not obvious; The effects of initial temperature on burning characteristics is small. The best mixed proportions of butanol and hydrogen is between5% and 15%. The best excess air coefficient is under 1.8.Finally, simulate the combustion characteristics of fuel on the conditions of real gasoline engine by the software of AVL Fire. Using the 3D output function of AVL Fire, analysis of the combustion process of mixed fuel under the condition of different proportions that butanol mixed hydrogen and different concentrations of mixed fuel. Results showed that with greater proportion of hydrogen the shape of flame is larger, the changes of temperature and pressure is more obvious while at the same time. When the concentration of mixture fuel changes, the speed of flame is change too. The flame propagation speed is extremely slow when the excess air ratio is 2.2.