Experiment And Numberical Simulation Research On The Combustion Performance Of Low Concentration Ethanol Gas Generator

The evaporation and combustion performances of different concentrations of ethanol, the combustion performance of the low concentration ethanol-hydrogen peroxide gas generator, and the problem of flameout of the low concentration ethanol-hydrogen peroxide gas generator were researched through theoretic analysis, experimental investigation and numerical simulation. Many significant results, which were important to design and optimize the low concentration ethanol-hydrogen peroxide gas generator, were acquired.First, the flame configuration and combustion efficiency in the conditions of different concentrations (50%, 65%, 85%) of ethanol were obtained through the ethanol/oxygen gas generator fenestration experiment and numerical simulation. The influence of multicomponent of low concentration ethanol on the evaporation and combustion performance was investigated and the exactness of the simulation was validated. The analysis showed that high speed of the oxygen had marked influence on the angle of the flame. When the excess oxidizer coefficient was bigger, the angle of the flame was smaller. The concentration of ethanol was higher, and the evaporation was quicker, the flame was brighter. When the excess oxidizer coefficient was unconverted, the concentration of ethanol was higher, the combustion efficiency was better.Second, for the demands of project, the influence of excess oxidizer coefficient, flux density and the stay time in the combustion chamber on the combustion performance of the low concentration ethanol-hydrogen peroxide gas generator were investigated by experiment and simulation. The results showed that the gas generation could work under a large-scale of temperature, excess oxidizer coefficient and flux density. Besides, the stay time played an important role on the combustion performance.In the end, the problem of flameout of the low concentration ethanol-hydrogen peroxide gas generator the flameout was studied, by means of theoretic analysis, experiment and simulation, the influence of the velocity of the decomposed gas of hydrogen on the abnormal flameout of the gas generator. The analysis showed that diluted ethanol receded the velocity of the chemical reaction, and the the velocity of the decomposed gas of hydrogen played a key role on point that whether the gas generator worked normally after ignition. When the injection pressure drop of the decomposed gas was 1.0MPa, the velocity of the decomposed gas was so high that the flame could not stay in the combustion chamber, thus the gas generator extinguishes abnormally; and if the injection pressure drop reduced to 0.2MPa, the velocity of the decomposed gas was lower, and the gas generator worked normally.