The Study Of Ignition And Combustion Of The Primary Combustion Products Of The Boron-based Fuel-rich Propellant

The primary combustion products of the boron-based fuel-rich propellant are burned in the afterburning chamber of solid ducted rocket, the properties of the primary combustion products have a very important affect on the performance of the rocket. The microcosmic character and the composition of the primary combustion products are detected by a various of instruments, meanwhile the composition and thermodynamic parameter of the primary combustion products are calculated by the software of FactSage. The influence of different proportion B4C and CO2of the sample on the ignition and combustion characteristics of boron particles are studied by TG-FTIR,TG-DTG and laser ignition experiments and software of FactSage. Different primary combustion products have been study to get the thermal oxidation and combustion characteristics. The rules and effect of the environment temperature, pressure, oxygen concentration and CO2concentration on the ignition and combustion characteristics of the primary combustion products are analyzed.The microcosmic character and the composition of the primary combustion products are detected by a various of instruments, the thermodynamic parameter and composition of the primary combustion products are H2, CO, HCl, CO2, C,B4C and BN,which are calculated by the software of FactSage. The XRD, EDS and XPS tests imply that the primary combustion products are composed of B, C, B4C and a small quantity of B2O3, NH4Cl.The influence of different proportion B4C and CO2of the sample on the ignition and combustion characteristics of boron particles are studied by experiments. The results indicate that B4C could promote the rate of weight gain and lower the initial oxidation temperature of the sample below the temperature of1000K. As the proportion of B4C in the sample increase, the rate of weight gain decrease between the temperature of1000～1250K, the weight gain ratio decrease and the temperature decline corresponding maximum rate of weight gain at the temperature of1250K. The rate of weight gain increase again between the temperature of1250～1700K, the rate is faster with more B4C. As the proportion of B4C in the sample increase, the intensity of combustion spectrum get weaker and the highest of spectrum peak value reduce rapidly, the ignition delay time get longer and the combustion time get shorter. With the increase of CO2concentration, the rate of weight gain of the sample increases and the temperature corresponding maximum rate of weight gain declines, the ignition time and the combustion time get shorter, which indicate that CO2could promote the oxidation rate of boron.The thermal oxidation and combustion characteristics of the primary combustion products are studied by different experiments. The reaction of NH4CI, C and B4C are affirmed by the FTIR. The experiment results indicate that the weigh loss and heat release of the sample are samller which got at higher pressure, and the intensity of combustion spectrum is weaker, the ignition delay time is shorter and the combustion time is longer.The influence of different proportion O2, CO2and pressure on the thermal oxidation and combustion characteristics of the primary combustion products are studied by experiments. With the increase of O2concentration, the rate of weight loss and heat release of the sample increase between the temperature of750～850K, the heat release of the sample increases again after the temperature of900K, the temperature corresponding maximum rate of weight gain declines, the intensity of combustion spectrum gets stronger and the highest of spectrum peak value increases rapidly, the ignition delay time gets shorter and the combustion time gets longer, which indicate that O2could promote the ignition and combustion of the primary combustion products. With the increase of O2concentration and the O2concentration is stable, the rate of weight loss and heat release of the sample reduce between the temperature of750～850K, but the rate of weight gain and heat release of the sample increases after the temperature of900K, and the initial oxidation temperature of the sample declines. So it indicates that CO2could promote the oxidation c of the primary combustion products. With the increase of the ambient pressure, the rate of weight loss of the sample declines during the weight loss stage. The weight gain of the sample increases and the initial oxidation temperature declines during the weight gain stage.