Экспериментально-аналитические исследования токсичности продуктов горения, обнаружения и тушения пожаров в гермобарокамерах в средах, обогащенных кислородом и при повышенном давлении

Abstract

Experimental and analytical studies were carried out related to the detection and extinguishing of fires, the toxicity of products in equipment with oxygen-enriched media and at elevated pressure. Toxicity of combustion products in the pressurized pressure chambers is due to the release of aerosol particles and gaseous products of thermal-oxidative destruction of materials, for which empirical dependences are presented over a wide temperature range allowing calculations to determine the integral relative yields of reaction products. Analysis of the experimental results shows that the increase in the mass yield of aerosol particles occurs more intensely than that of toxic gases, and a noticeable release of gases begins at a temperature of about 523 K, while the release of dispersed particles occurs already at a temperature of approximately 473 K. At the early stage of thermal destruction in the temperature range 473–623 K, the yield of aerosols is 5 times higher than the yield of gases by mass. When the temperature rises close to the ignition temperature, the combustion source can be detected using gaseous products, in particular CO and CO2. Justification for the methodology for assessing the main parameters of fire extinguishing in the pressurized chambers is given. The most important elements of the main components, elements and installation as a whole are: inertia, intensity of supply of fire extinguishing agent. Dependence obtained analytically, which was confirmed in experiments, between the extinguishing time and the intensity of the supply of fire extinguishing agent is presented, which considers the characteristics of the environmental parameters in the chamber and the thermophysical properties of the flame. Dependences were obtained related to the extinguishing time on the intensity of the supply of sprayed water, on the size of the sample, and on the oxygen content in the chamber atmosphere. Results of the experimental studies indicate that changes in oxygen concentration in the atmosphere have a more noticeable effect on extinguishing parameters than changes in gas pressure.