No abstract

A methodological approach has been developed to quantify the amount emission harmful substances in an industrial accident. An algorithm for calculating the most probable, acceptable, safe for the environment the amount of harmful substance contained in the release in the event of an emergency at the facility. Adoption of an expedient solution is facilitated by an integrated approach based on determining the parameters of the operation of emergency ventilation and environmental protection measures. The prediction of the amount of harmful substances in the case of mass emissions at a chemically hazardous facility is based on determining the ratio of the height of emission sources, taking into account the differentiation of cleaning methods and their effectiveness.

The results of the study concentration field of chemical harmful substances in the entire volume of the room during the operation of emergency ventilation with a given air exchange are proposed. Explosion safety of production rooms is provided on condition of 10 % of the lower limit of flame spread on gas-air mixes and observance of equality of concentrations of harmful substance in the working zone and in the leaving air. Emergency ventilation is proposed, which provides uniform removal of air from the entire volume of the room to exclude the formation of stagnant zones and ensure explosion safety in chemical emissions. Emergency ventilation with a natural flow of air through the holes with variable aerodynamic characteristics with a volume-oriented arrangement of supply and exhaust holes to ensure uniformity of the flow and removal of air from the entire volume of the production room.

The energy balance of buildings depends greatly on the type of external fencing, including translucent. The article presents a brief description of different types of daylighting systems that have different optical, geometric and thermal characteristics. The change in these characteristics affects the quality of lighting in the room, as well as determines the operating costs associated with losses and heat flows into the building through translucent fences. The task of comparing and choosing the optimal daylighting system should take into account all of the above factors. The authors propose a complex comparison criterion that takes into account thermal, optical, operational properties and capital costs. The structure of the proposed criterion allows you to add new indicators or remove irrelevant for a particular consumer comparison parameters. The method is composed and the calculated dependences for determining the numerical value of individual indicators included in the complex criterion are given. All parameters included in the proposed criterion have no dimension. This makes it possible to reduce the dependence of the calculations on changes in current energy prices.

In the event of an emergency situation at an industrial site with the release of ventilation systems into the atmosphere, a cleaning device is required, which should ensure that the excess of the explosive concentration in the surface layer of the atmosphere is above the normative value. Quantitatively, the release of explosives depends on the degree of depressurization of the system, its volume and pressure in it, the speed of the formation of the team to close the shut-off organs and its execution. The purification device of emergency emissions should have the properties of adequate counteraction to the specified accident factors for equipment that does not have internal self-protection. The emergency emissions are of a probabilistic nature, and therefore the structure of the treatment equipment and its operating conditions must differ from the structure and conditions when cleaning only technological emissions. The cleaning equipment must be able to neutralize large mass outlays of emissions in a short period of time, the operation of the equipment must be built on the principle of waiting for work, that is, in the automated mode, the time of entry into operation should be determined when hazardous concentrations of explosives in the room occur. The performance of the exhaust emergency ventilation and the moment of its activation are determined by the conditions for reaching the concentration of explosives in the room not exceeding 0,1 of the lower concentration limit of flame propagation in gasair explosive mixtures and ensuring dispersion of surface concentrations not higher than the established standard values, and for non-explosive mixtures – Only the second condition.