Laboratory method of determining the rate of burnout of liquid fuel

Introduction. In accordance with the provisions GOST 12.1.044-89 (ISO 4589-84) (Fire and Explosion hazard substances and materials. Nomenclature of indicators and metods of their determination) one of the important parameters of liquid combustion are the mass rate of liquid burnout and the influence of various conditions of the combustion process on the mass burnup rate. A laboratory method for determining the mass burnout rate of a combustible liquid has been developed. Goals and objectives. The aim of the study is to develop a laboratory method for determining the mass rate of liquid burn-up, which can be used in the educational process during laboratory work and to simulate the effect of combustion conditions on the mass rate of liquid burn-up. Methods. To implement this task, we used video recording of changes in the mass of the liquid during its combustion in vessels of different diameters, followed by graphical processing of the results of experiments for calculate the burn-up rate under different combustion conditions. Results and discussion. The method was tested on the example of the combustion of acetone. An example of computer-graphical result for calculating the mass rate of acetone burn-up is given. The empirical dependents of the acetone burn-up rate on the diameter of the liquid surface area is obtained. Conclusions. A laboratory method for determining the mass rate of burnout of a flammable liquid, which can be used in the educational process during laboratory work, has been developed. In contrast to GOST 12.1.044-89 (ISO 4589-84), the developed method can use vessels with a liquid diameter of more than 60 mm. Keywords: burnout rate, acetone, laboratory technique

METHODS OF LABORATORY RESEARCH OF EXTINGUISHING PROCESSES PECULIARITIES OF HIGH-BOILING COMBUSTIBLE LIQUIDS

According to the analysis of literature sources of extinguishing of high-boiling combustible liquids, several key issues were identified that should be determined during experimental research of extinguishing processes, namely: dispersion of spraying, particle velocity of water extinguishing agent, temperature of its supply, change in concentrations of impurities-combustion inhibitors, the temperature of liquid layer, investigated the intensity of liquid combustion (size of torch of combustion, control of combustion intensification presence or absence). The need of development of individual methods of laboratory research of water-based fire extinguishing substances and their supply parameters to minimize the intensification of the combustion processes of high-boiling combustible liquids, taking into account the specificity of their extinguishing, has been determined. The proposed improved methods of research of extinguishing processes of high-boiling combustible liquids provides control of the temperature of model fireplace, the temperature of extinguishing agent, and the use of the TESTO 885 thermal-imaging device provides visualization of model fireplace size and shape during extinguishing process. The parameters of cutting of Danfoss nozzle 0,40 Gph 80 ° were experimentally determined in terms of its use for cutting of distilled water at pressures of 4.6 and 8 bar. The possibility of using thermographic equipment with a spectral range from 7 to 14.5 microns for research the features of the interaction of sprayed water extinguishing agents with high-boiling combustible liquids are experimentally identified. The characteristic images of individual stages of processes allow to visualize external dimensions of flame and its character, especially in the conditions of reducing the limits of measurements for further programmed processing of the video sequence. Minimization of combustion intensification shall be the subject of further research of the authors. Changing the initial conditions of supply of sprayed water, its initial temperature, the intensity of supply, using impurities-combustion inhibitors, it will be necessary to determine conditions for the most effective extinguishing of fires of turbine oil spills of the TP-22 brand.

Effect of Nitric Acid Modification on LiMn2O4 Prepared by Solution Combustion Synthesis

Effect of nitric acid and the burning time on the liquid combustion synthesis of spinel LiMn2O4 has been studied, using lithium nitrite and Manganese acetate as raw a material. The results show that the main phases are all LiMn2O4, which can be obtained at 400-600 oC. Before modified, the impurity is Mn3O4 or Mn2O3. After modified, the impurity is only Mn3O4. The aggregation obviously reduced after adding nitric acid, it is indicated that the crystalline increased. With the increasing temperatures, the modified particle size was increased and the aggregation reduced. The initial discharge capacity and cycle stability improved at some extent too. Its first discharge capacity was 104.6, 112.8 and 117.7mAh/g synthesized at 400, 500, 600 oC, respectively, and the 30th capacity retention rate were 84.89%, 80.67% and 73.24%.

Numerical Simulations of Two-Phase Turbulent Combustion in Spray Burners

The complex interactions among turbulence, combustion and spray in liquid-fuel burners are modeled and simulated via a new two-phase Lagrangian-Eulerian-Lagrangian large eddy simulation (LES) methodology. In this methodology, the spray is modeled with a Lagrangian mathematical/computational method which allows two-way mass, momentum and energy coupling between phases. The subgrid gas-liquid combustion is based on the two-phase filtered mass density function (FMDF) that has several advantages over “conventional” two-phase combustion models. The LES/FMDF is employed in conjunction with non-equilibrium reaction and droplet models. Simulations of turbulent combustion in a spray-controlled double-swirl burner are conducted via LES/FMDF. The generated results are used for better understanding of spray combustion in realistic turbulent flow configurations. The effects of spray angle, mass loading ratio, fuel type, droplet size distribution, wall and inflow/outflow conditions on the flow and combustion are investigated. The LES/FMDF predictions are shown to be consistent with the experimental results.