Kostenko T. Development of scientific bases for improving safety of rescuers during emergency rescue works under the conditions of heating microclimate

The thesis is devoted to the solution of the pressing scientific and practical problem of improving safety of rescuers during the execution of emergency rescue works under the conditions of heating microclimate using the advanced fire extinguishing equipment to cool rescuer’s body and surfaces of personal heat-protective equipment. The analysis of the occupational traumatism carried out in the units of the State Emergency Service of Ukraine has shown that 12% of victims received thermal injuries – the fact that proves the urgency of the research. A qualitative assessment of extreme hazards during firefighting on the basis of the analysis of the "human body - the source of combustion - protective equipment - environment" system is carried out. It was established that the footprint of the damage areas caused by the negative factors of fire are not stable in time and space, therefore it is relevant to carry out regular monitoring of the boundaries of damage areas. The monitoring should result in the management of protection parameter against the effect of heat. Ground-reflected rays have, for the first time, been proved to be able to add up to 30% to the already received direct rays from the source of combustion. The specified ways of heat rays contact with the rescuer during the elimination of a large-scale fire should be taken into account when determining the thermal load on the body. It was established that the dependence of the radiation heat flux during the combustion of petroleum products on the geometric parameters of the reservoirs they are preserved in (namely, height and diameter) allows to determine in advance the boundaries of zones of the heat-protective equipment usage. The balance of the thermal load on the rescuer’s body was for the first time complemented by the components of the influence of direct and reflected sunlight during emergency rescue works in the open air. The concept for the efficient estimation of the influence of solar radiation on the manpower by calculating the levels of direct and reflected sunlight is theorized. The concept of the mechanism of rescuer’s body thermoregulation, inclusive of the effect of the heat transfer coefficient by convection in underclothing space, thermal insulation coefficient of clothing, partial pressure of water vapor above the skin surface and in the air have been further developed . The influence of moisture absorbing elements with absorbent substance on the heat transfer in the under-clothing area during physical activity is offered and empirically investigated. The analytical model of mathematical modeling of heat transfer from the source of combustion to the surface of protective clothing and further to the body of the rescuer is offered. A computer simulation of the thermal impact on the body of the rescuer during the extinguishing of fire that arose in the tank with gas using ANSYS Multiphysics environment was made. The regularities of the temperature distribution on the surface of protective clothing and rescuer’s body during the combustion of petroleum products were obtained, which allowed to identify the most vulnerable places, namely, the zone of the upper part of the bosom and the zone of feet and legs. For the first time, the "environment - source of combustion - means of individual protection - human body” system under the conditions of heating microclimate was expanded with "fire extinguishing" element which allowed to theorize the ways of controlling thermal yield from human body and cooling the surface of special clothing. The concept of the efficiency of direct-flow body cooling model using fire extinguishing agents as a refrigerant has been further developed. The advantage of water film protection of the surface of the personal protective equipment over the drip curtain allowed to prove the idea of preventing thermal destruction of rescuers’ protective clothing fabric. Design schemes and elements of constructions of water and foam cooling devices have been developed. The efficiency of devices for increasing the protective properties and the life of special clothing of rescuers has been experimentally confirmed. Empirical research proved that the presence of 100 microns water film reduces the infiltration of infrared radiation by 85%, and a film of 200 microns or more allows virtually all heat energy to be redirected into the water stream. The device for face protection during emergency and rescue works under the conditions of high thermal radiation was improved. Automation of protection from thermal damage during the initial stage of fire liquidation was offered for the first time. An automatic thermal protection device for the protection of the rescuer was developed and experimentally researched; its efficiency is proved by the results of tests of the prototype sample of the cooling device.