Determination of conformity of international and national methods of classification of gasvaporair explosive zones

 

Oleg Kulakov

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0001-5236-1949

 

Yuliia Mykhailovska

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0003-1090-5033

 

Albert Katunin

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0003-2171-4558

 

Oleksii Roianov

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0001-7631-1030

 

DOI: https://doi.org/10.52363/2524-0226-2023-37-8

 

Keywords: explosive zone, explosive environment, pump station, nomogram, room, light oil products

 

Аnnotation

 

Discrepancies between the international and national methods of classification of gas-vapor-air explosive zones (the method of the final edition of DSTU EN IEC 60079-10-1 and the method of NPAOP 40.1-1.32) were revealed using the example of the premises of pumping stations for pumping light petroleum products. When applying the international method, either an explosive zone of class 1 or an explosive zone of class 2 can be formed, or an explosive zone is not formed. The class of the zone depends on the mass rate of gasoline leakage and the ventilation rate (with a high mass rate of gasoline leakage and a low ventilation rate, a class 1 zone is formed; with an increase in the ventilation rate and the constant rate of gasoline leakage, either a class 2 zone is created or the conditions for its creation are absent). The explosive zone of class 2 acquires significant dimensions only in case of significant emergency leaks (in particular, it occurs at a distance of 5 m with a total mass leakage rate of 132,81 g per 1 kg of gasoline pumped). The explosive zone occupies the entire room only if its size exceeds the geometric dimensions of the room, taking into account the place of release of the hazardous substance. The time of existence of the explosive zone depends on the stationary background concentration of gasoline according to the logarithmic law. The frequency of air exchange in the room significantly affects the time of existence of the explosive zone. When applying the national method in the room, either an explosive zone of class 2 or no explosive zone can be formed. The criteria for the formation of an explosive zone by different methods differ significantly. The elimination of identified discrepancies is possible either by a complete transition to European technological regulations with the cancellation of the national method of calculation or by incorporating the international method of calculation into the existing national rules after their comprehensive technical examination.

 

References

 

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Influence of smoke density on the parameters of the acoustic device of the rescuer's equipment

 

Alexander Levterow

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0001-5926-7146

 

Yevhenii Statyvka

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0003-1536-2031

 

DOI: https://doi.org/10.52363/2524-0226-2023-37-7

 

Keywords: acoustic device, sensor, acoustic resistance, reflection coefficient, visual control

 

Аnnotation

 

Experimentally determined correction values of the distance to the obstacle depending on the acoustic impedance of the environment for the acoustic device of the rescuer's equipment. The measurement results were obtained using the developed experimental setup, which took into account, in real time, changes in acoustic impedance and temperature of the environment using a two-channel temperature meter and an optical penetration sensor of the environment. The temperature of the environment (in the confined space) varied from 20 °C to 60 °C, and the optical penetration index from 0 to 100 %, where 100 % corresponds to complete optical opacity of the environment. Dependencies of the propagation of acoustic waves upon changing the optical permeability of the medium and temperature were obtained. The correction value for the distance to the obstacle calculated by the acoustic device at a distance of 1000 mm was (+0,013 m). The relative error during the measurements did not exceed 2 %. It was found that when the wave impedance increases, the indicators of the distance to the obstacle decrease, so the corrective dependence has a positive value. The obtained results make it possible to increase the reliability of the readings of the acoustic device as an additional equipment of the rescuer. The data obtained as a result of the experiment make it possible to display the shape of the obstacle in more detail. Approximating polynomials of the reflection coefficient of acoustic waves depending on the volume content of inclusions at angles of incidence from 0 °С to 30 °С have been determined. The use of the obtained polynomials allows to increase the speed of the program code of the control microcontroller of the acoustic device. The obtained dependencies are taken into account in the calculation algorithm of the program code of the microcontroller of the acoustic device for determining the shape and distance to the obstacle, which makes it possible to increase the efficiency of the rescuer's orientation in conditions of unsatisfactory visual control during emergency rescue operations.

 

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Improvement of risk-based management of occupational safety and hygiene

 

Bohdan Tsymbal

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0002-2317-3428

 

Olena Sharovatova

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0002-2736-2189

 

Artem Petryshchev

National University "Zaporizhzhya Polytechnic"

http://orcid.org/0000-0003-2631-1723

 

Alexandr Malko

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0003-4868-7887

 

Sergey Artemev

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0002-9086-2856

 

Oleg Bogatov

Kharkiv National Automobile and Highway University

https://orcid.org/0000-0001-7342-7556

 

DOI: https://doi.org/10.52363/2524-0226-2023-37-5

Keywords: risk-oriented management, occupational safety and hygiene, occupational risk assessment methodology, occupational risk management, methodology testing

 

Аnnotation

 

The importance of improving a risk-oriented approach is considered, as such an approach allows to ensure a high level of safety and hygiene at the workplace, reduce the risk of negative consequences for employees and prevent material losses for the enterprise. The features of the main stages of risk-oriented management of occupational safety and health, such as identification, assessment and management of occupational risks, are analyzed. It was established that the most problematic stage is the assessment of professional risks. The analysis of methods for determining the level of risk and assessing the effectiveness of risk management measures showed that these methods are general and are not adapted to the specifics of various sectors of the economy. Simplified methods take into account only two components: the probability of exposure of the hazard to the worker and the damage or consequences. Three-component methods also take into account the frequency (tendency) characteristic of danger. At the same time, three-component methods do not have a matrix for assessing occupational risk. The vast majority of such methods do not provide an assessment of the residual risk, which shows the effectiveness of measures to reduce the level of occupational risk and the need for the implementation of corrective measures. At the same time, the hierarchy of control measures and the time limit for the implementation of preventive and protective measures are not taken into account. To eliminate these shortcomings, a three-component 3-D method of occupational risk assessment has been developed, which contains a volume matrix and allows to assess the residual risk. The obtained results of the implementation of the proposed methodology can be used in practice to improve safety and occupational hygiene at machine-building enterprises. The results of the study make it possible to reduce the number of accidents at the workplace and ensure an increase in the efficiency of occupational safety and health management.

 

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Features of heat release rate simulation methods in FIRE DYNAMICS SIMULATOR

 

Stanislav Vinogradov

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0003-2569-5489

 

Stanislav Shakhov

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0003-3914-2914

 

Dmytro Saveliev

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0002-4310-0437

 

Andrii Melnychenko 

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0002-7229-6926

 

Oleksandr Polivanov

National University of Civil Defenсe of Ukraine

https://orcid.org/0000-0002-6396-1680

 

DOI: https://doi.org/10.52363/2524-0226-2023-37-6

 

Keywords: fire research, fire safety, heat release rate, Fire Dynamics Simulator, PyroSim

 

Аnnotation

 

The peculiarities of the methods of modeling the rate of heat release in the Fire Dynamic Simulator have been revealed. The change in the rate of heat release over time was compared, depending on the modeling method, and methods were practically implemented on the example of a typical room to identify the influence of the rate of heat release on the development of dangerous fire factors. When using the Fire Dynamic Simulator to study hazardous factors in full, it is not clear what value of the heat release rate should be used when studying the dynamics of fire development, which affects the evaluation of the obtained results. Identifying the features of each of the methods will make it possible to use them effectively in order to properly assess the results obtained and further ensure the level of fire safety. As a result of the comparison of the change in the rate of heat release over time, depending on the modeling method, a classification of modeling methods was developed. During the practical implementation of the methods on the example of a typical room, it was found that when the first modeling method is used compared to the second, the temperature rise in the threaded time intervals increases by 1,5–3 times faster, respectively. During the analysis of the loss of visibility, it was found that when using a constant rate of heat release, the reduction of visibility at different time intervals is achieved faster than when the rate of heat release changes over time, respectively, by 1,6–3 times. During the analysis of the decrease in oxygen concentration, it was established that when using the first modeling method, the value of the oxygen concentration in the air decreases 1,2–1,6 times faster at different time intervals compared to the indicators of the second method. Thanks to the identified features of each of the modeling methods, recommendations for their use in FDS have been developed. This makes it possible to effectively apply methods and evaluate the results with subsequent decisions to ensure an adequate level of fire safety.

 

References

 

  1. Xinfeng, Long, Xueqin, Zhang, Bo, Lou. (2017). Numerical simulation of dormitory building fire and personnel escape based on Pyrosim and Pathfinder, Journal of the Chinese Institute of Engineers, 40:3, 257–266. doi: 10.1080/02533839.2017.1300072
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  5. Yanjie, Ju. (2021). A fire simulation method of urban light rail station hall based on building information model and pyrosim software. J. Phys.: Conf. Ser. 1903 012065, 1–7. doi:10.1088/1742–6596/1903/1/012065
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Operational readiness of an elementary fragment of the departmental digital telecommunication network DSNS.

 

Andrey Feshchenko

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0002-4869-6428

 

Alexander Zakora

National University of Civil Defenсe of Ukraine

http://orcid.org/0000-0001-9042-6838

 

Evgen Morshch

Department of Emergency Prevention of the SES

http://orcid.org/0000-0003-0131-2332

 

DOI: https://doi.org/10.52363/2524-0226-2023-37-4

 

Keywords: emergency, digital telecommunications network, reliability, operational availability, probability of failure-free operation

 

Аnnotation

 

The research goal of developing a probabilistic model of an elementary fragment of a departmental digital telecommunications network, which takes into account the influence of the redundancy structure and operational parameters of fail-safe and maintainability of its nodes and data transmission channels on its operational readiness coefficient, has been achieved in the work. Expressions of the coefficient of operational readiness of the probabilistic model of an elementary fragment of a digital telecommunication network after failures in emergency conditions were obtained and analyzed, and the relationship between the coefficient of readiness and operational parameters was established. It is indicated that the required coefficient of operational readiness of an elementary fragment of a digital telecommunication network is achieved not only by increasing the reliability of nodes, but also by choosing a redundancy structure and a mode of maintenance of equipment, which have not been determined before, therefore studies are made of the dependence of the coefficient of operational readiness of an elementary fragment of a departmental telecommunications network on standardized operating conditions parameters for structures without redundancy and with redundancy by statistical mathematical modeling. As a result of the research, it was established that in order to achieve the required operational readiness ratio while reducing the requirements for the reliability of the nodes of the elementary fragment of the departmental digital telecommunication network, it is sufficient to apply structurally separate two-fold redundancy of nodes in the presence of triple redundancy of data transmission channels. Research data are useful and important for predicting the operational readiness ratio when designing and planning the required mode of maintenance of nodes and data transmission channels of an elementary fragment of the departmental telecommunications network, depending on the ratio of the period of preventive work to the time spent on failure during operation.

 

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