Recording of the Cavitation Phenomena when Modeling Flows in the Trunk Pipelines

2020 ◽  
pp. 7-14
Author(s):  
A.M. Sverchkov ◽  
◽  
S.I. Sumskoy ◽  
Keyword(s):  
Occupational Safety ◽  
Linear Part ◽  
Simple Wave ◽  
Pressure Profile ◽  
Real Problem ◽  
Flow Modeling ◽  
Oil Pipeline ◽  
Emergency Situations ◽  
Hydraulic Shocks ◽  
The Waves

In the article, it is proposed to use a numerical method based on the approach of S.K. Godunov to simulate boiling in a pipeline. The paper presents a statement of the real problem of modeling a water hammer, considering possible boiling of the transported liquid on a real object — an oil pipeline. When solving the problem, two variants of flow modeling when closing the valve installed at the end of the pipeline were carried out. In the first Наука и техника 14 Безопасность Труда в Промышленности • Occupational Safety in Industry • № 11'2020 • www.safety.ru case, the possibility of liquid boiling was not considered. In the second case, this opportunity was considered. The performed numerical simulation showed that in the pipeline in emergency situations, liquid columns can be formed, separated by the cavitation zones and oscillating in different phases, respectively, at the collapse of the cavitation zones, which serve as a kind of pressure dampers, the collisions of liquid columns occur, which can lead, depending on the ratio of velocities, to hydraulic shocks that occur not on the valves, but on the linear part of the pipeline (local hydraulic shocks). The waves from these collapses, interacting with each other, create the new pressure peaks that do not coincide with the pattern of simple wave circulation, which are predicted in the simulations that do not consider possible liquid boiling. As a resul t, the pressures reached in the pipeline during fluid hammer is significantly different from what it would be in the absence of boiling. When boiling is considered, the maximum reached pressures are 40 % higher. Moreover, this excess is repeated. The detailed analysis of the pressure profile in the pipeline is given in the article. Based on the results of solving this problem, it is concluded that when modeling pre–emergency and emergency situations in the pipeline, it is necessary to consider the process of possible liquid boiling, since sometimes, as in the presented case, the values of the pressure surges can be higher than the values of the pressure surges in the liquid without considering boiling, which increases the likelihood of emergency depressurization.

scholarly journals ESTIMATION OF THE VALUE OF OIL LOSS DURING THE SEALING OF THE LINEAR PART OF THE PIPELINE

2021 ◽  
pp. 142-150
Author(s):  
V. T. Bolonny
Keyword(s):  
Linear Part ◽  
Petroleum Products ◽  
System Failures ◽  
Oil Pipeline ◽  
Emergency Situations ◽  
Oil Leakage ◽  
Oil Transportation ◽  
Time Period ◽  
Oil Pipelines ◽  
Pollution Area

The characteristics of the oil transportation system of Ukraine are presented, the emergency risks of domestic oil transportation pipeline sys­tems are established. The analysis of the accident rate of oil pipeline trans­port in Ukraine was carried out. The technique for estimating emergency oil leakages in the main pipeline depending on the energy characteristics of the fluid flow and changes in its level in the cross section is developed allowing to determine the volume of oil leakages into the environment from the de­tection of pressure drop to the establishment of stationary conditions of the pipeline operation and its final stop for the purpose of carrying out repairs. Based on the results of the calculations, the graphs which demonstrate the nature of the formation of soil pollution area by leakage from the pipeline are constructed. The linear part of the main oil pipelines is the most dangerous object, as all emergency situations are associated with emergency processes of dif­ferent intensity in the form of oil leakage into the environment and in fact are dangerous when system failures appear. The process and the time period for the formation of the ecological danger zone depend on the amount of oil leakage, its intensity. Emergency leakages of oil and petroleum products from pipelines enter the environment, which is often the soil, forming an area of gassiness, and then reach the surface, polluting the atmosphere.

New requirements for power frequency electric field and induced current personal protective equipment

2020 ◽  
Vol 60 (11) ◽  
pp. 849-852
Author(s):  
Sergey Yu. Perov ◽  
Tatyana A. Konshina ◽  
Elena N. Makarova-Zemlyanskaya
Keyword(s):  
Electric Field ◽  
Personal Protective Equipment ◽  
Occupational Safety ◽  
Protective Equipment ◽  
Safety Standards ◽  
Emergency Situations ◽  
Step Voltage ◽  
Power Frequency ◽  
Staff Protection ◽  
Frequency Electric Field

In conditions of exceeding the maximum permissible levels of power frequency electric field, the staff must use personal protective equipment. Requirements for such means are regulated by the system of occupational safety standards. The goal of this work is analyzed new requirements for power frequency and induced personal protective equipment in the regulatory interstate standards GOST 12.4.172 and GOST 12.4.283. The personal protective equipment new requirements for various types of work are substantiated to electrical personnel health safety during the maintenance and operation of power grid facilities. Increasing requirements for personal protective equipment improves the staff protection at ground potential and at wire potential, including in emergency situations such as induced and step voltage.

Consideration of Non-stationarity in the Development of Emergency Situations for the Quantitative Risk Assessment of Accidents at Hazardous Production Facilities of Oil and Product Pipelines

2021 ◽  
pp. 89-96
Author(s):  
A.M. Sverchkov ◽  
Keyword(s):  
Risk Assessment ◽  
Fire Hazard ◽  
Ignition Time ◽  
Quantitative Risk Assessment ◽  
Risk Indicators ◽  
Oil Pipeline ◽  
Emergency Situations ◽  
External Conditions ◽  
Hazardous Production ◽  
Real Practice

It is proposed to use the new approach to assessing quantitative risk indicators. This approach allows to consider the temporal non-stationarity of the number of processes, including the development of an accident and the spatial movements of people. The greatest uncertainty in the risk analysis with an explosive and fire hazard component is not the frequency of initiating events used, but, for example, data on the probability of ignition. The range of variation of this probability is about two orders of magnitude (relatively speaking, from 1 % to 100 %), and the criteria and factors that determine the choice of this value are not always clearly defined. The paper proposes an approach that considers the probability of ignition as a dependence on the time that passed after the start of emergency depressurization. Knowing this dependence, it is possible to consider several scenarios with different ignition time after the start of the release and assign certain consequences and probabilities to each scenario. Moreover, it is possible for each single scenario on a specific piece of equipment (pipeline section) to obtain non-stationary, namely time-varying potential risk fields. The example of an accident on the oil pipeline is considered, the risk indicators of such an accident are calculated, it is shown that the risks can change over time, namely they are non-stationary characteristics. Further, this fact is transformed into the development of theoretical foundations for quantitative risk assessment, considering the non-stationarity of various processes occurring during emergency situations arising during the operation of equipment, individual behavior of people and changes in external conditions. The results obtained show the importance of considering the changes that occur during an emergency on the main oil and product pipelines. It is concluded that the proposed approach allows to reduce the conservatism of assessments provided by traditional methods. In real practice this approach can reasonably reduce the risk indicators by several times, sometimes by orders of magnitude.

Fluid Flow Modeling and Simulation for the Coaxial Cable of the LEASAT Antenna System

1992 ◽  
Vol 114 (3) ◽  
pp. 358-360
Author(s):  
Hsien-Yang Yeh ◽  
Hen-Geul Yeh
Keyword(s):  
Fluid Flow ◽  
Pressure Profile ◽  
Antenna System ◽  
Gas Pressure ◽  
Coaxial Cable ◽  
Flow Modeling ◽  
Modeling And Analysis ◽  
Modeling Analysis ◽  
Analysis Computer ◽  
Fluid Flow Modeling

A preliminary fluid flow modeling, analysis, and simulation of the gas pressure profile within a 259 cm long coaxial cable is presented. This coaxial cable is part of the antenna system of the LEASAT satellite. To eliminate the possibility of any corona or arcing phenomenon inside the coaxial cable during operation of the satellite, it is necessary to not only prove experimentally but also show analytically that the gas pressure inside the cable drops down and stays below 0.01 Ton within 24 hours after the satellite enters into its orbit. In this paper, only the analytical work is discussed. The continuum fluid mechanics and the kinetic theory of gases are applied for modeling and analysis. Computer simulation is done by using an IBM XT and the results are presented.

scholarly journals OCCUPATIONAL SAFETY RISK ANALYSIS OF ORGANIZED INDUSTRIAL ENTERPRISES IN NEVSEHIR PROVINCE OF TURKEY BY FINE-KINNEY METHOD

2020 ◽  
Vol 7 (7) ◽  
pp. 33-41
Author(s):  
M. Cüneyt Bagdatlı ◽  
Ahmet Mahmut KILIÇ
Keyword(s):  
Risk Factors ◽  
Risk Analysis ◽  
Occupational Safety ◽  
Preventive Measures ◽  
Health And Safety ◽  
Safety Risk ◽  
Emergency Situations ◽  
Industrial Enterprises ◽  
Electrical Components ◽  
Excessive Noise

This research has been carried out within the scope of the solutions proposed for the evaluation of occupational safety risk analysis in 10 selected enterprises by random sampling in Organized Industrial Zone of Nevşehir province, Turkey and elimination of risk factors towards the results obtained. In scope of the study, Fine – Kinney method were used as risk assessment methods in each of the food, metal processing, machining and plastic firms. At the end of the study, a total of 122 risk factors have been identified in the whole enterprises. Commonly risks arising from falling from heights, fire, exposure to chemicals, electrical components and ergonomic situation insufficiency have been identified. In addition, risks such as insufficient environmental hygiene, lack of ventilation, excessive noise, inadequate training for emergency situations and insufficient use of protective equipment were determined. The identified risks were put forward by different method approaches and it was concluded that the findings were similar in all methods. The regulations and principles to be applied in order to eliminate or minimize the identified risks were discussed and the dimensions of the preventive measures were exhibited. As a result, audits of organized industrial enterprises related to occupational health and safety need to be conducted more strictly. In addition, the measures should put into practice in order to define identified risks and the issue should be monitored by the experts.

scholarly journals ESTIMATION OF THE MAIN GAS PIPELINE OPERATION UNDER EMERGENCY CONDITIONS OF GAS LEAKAGE

2019 ◽  
pp. 122-131
Author(s):  
V. T. Bolonny
Keyword(s):  
Linear Part ◽  
Pressure Change ◽  
Gas Pipeline ◽  
Oscillatory Process ◽  
Gas Filtration ◽  
System Failures ◽  
Filtration Resistance ◽  
Gas Leakage ◽  
Emergency Situations ◽  
Time Period

The characteristics of the gas transportation system of Ukraine are presented, the emergency risks of domestic gas transportation pipeline sys­tems are established. The analysis of the accident rate of gas pipeline trans­port in Ukraine and Russia was carried out. Presented technique of deter­mining the emergency pressure in the pipeline, depending on the amount of gas losses from pipeline at the point of its leakage provides an opportunity to determine the volume of gas losses from the pipeline and to evaluate the environmental risks due to emergency situations of gas pipeline transport. This technique makes it possible to calculate the pressure at each point of pipeline under nonstationary conditions caused by changes in pressure at the beginning and at the end of the sector and the emergence of concentrated gas leakage. Based on the results of calculations, a graph of pressure change of the oscillatory process in the gas pipeline caused by jump of pressures at the beginning and at the end of the sector, and the presence of probable lea­kages at the determined point of the trace was constructed. The linear part of the main gas pipelines is the most dangerous object, as all emergency sit­uations are associated with emergency processes of different intensity in the form of gas leakage into the environment and in fact are dangerous when system failures appear. The process and the time period for the formation of the gas pollution zone depend on the amount of gas leakage, its intensity and depth of the gas pipeline. The filtration resistance of the soil as a porous medium, in particular its permeability, have a significant effect on the amount of gas leakage through corrosive orifice. As a result, there is a correlation between the amount of gas losses associated with the leakage, and the laws of its filtra­tion in the surrounding soil. As a result, the effect of gas filtration process in the soil in the event of leakage from pipelines has been investigated. The graphic dependence of change in pressure of the filtration resistance of the medium and the time-changing leakage which are designed for different soil characteristics is obtained.

Ensuring Occupational Safety in Emergency Response Associated with the Collapse of Buildings

2021 ◽  
pp. 58-64
Author(s):  
A.P. Savelev ◽  
◽  
A.A. Aksenov ◽  
I.K. Mishaev ◽  
◽  
...  
Keyword(s):  
Emergency Response ◽  
Occupational Safety ◽  
Software Implementation ◽  
Emergency Rescue ◽  
Emergency Situations ◽  
Risk Of Injury ◽  
Heavy Equipment ◽  
Preliminary Planning ◽  
Quick Determination

The problem of ensuring occupational safety during emergency rescue operations in the event of a collapse of buildings and structures is considered. Based on the statistics of accidents in the recent years provided by the National Center for Crisis Management of the Ministry of Emergency Situations of Russia, the relevance of this topic is determined. For reducing the likelihood of injuries and fatality, it is important to clearly plan, distribute and secure technical means and people at the work sites in the time-limited conditions. To solve this problem, it is proposed to apply the improved methodology for determining the forces and means required for debris handling and rescuing victims in the event of a collapse of buildings and structures. The methodology allows calculating the number of mechanized groups, links of manual disassembly and emergency rescue tools required for carrying out work on debris handling and rescuing victims under the specified meteorological conditions using the input parameters. The output parameters of the calculation according to this methodology are the number of heavy equipment and rescuers with the indication of the amount of work performed in accordance with the level of professional skills. A software implementation of this methodology is proposed, developed for quick determination of the required forces and means for debris handling, which can also be used for preliminary planning of emergency rescue operations and filling in the sections of the use of forces and means in the technical and information-reference documentation of the objects. Application of the recommended developments in practice will allow to reduce the risk of injury and fatality during emergency response associated with the collapse of buildings.

The Analysis of Ecologically Safe Operation of Oil Pipelines by Methods of the Stochastic Theory of Similarity

2020 ◽  
Vol 24 (10) ◽  
pp. 57-61
Author(s):  
T.V. Zinets ◽  
A.M. Gonopolsky
Keyword(s):  
Stochastic Theory ◽  
Environmental Safety ◽  
Structural Elements ◽  
Safe Operation ◽  
Nature Protection ◽  
Factors Affecting ◽  
Oil Pipeline ◽  
Emergency Situations ◽  
Main Pipelines ◽  
Oil Pipelines

In article it is shown that in the analysis of conditions of environmental safety of the main oil pipelines (MOP) with use of methods of the stochastic theory of similarity, it is necessary to consider not only the MNP design-technology parameters, but also various chemical mass-exchanged processes, for example, corrosion (oxygen, sulphurous and chloric corrosion), influencing changes of structural elements in time and space. For these reasons, dependences between parametrical criteria of similarity and their communications with stochastic criteria of similarity are the basis for the developed model. Comparative analysis was carried out by results of a research more than 70 emergency situations, at transportation of oil through the main pipelines of 18 companies. In parameters of accidents criteria ratios between the factors affecting environmental safety of MNP are received. It is established that average specific intensity of accidents on routes of the sites of the oil pipeline equipped adjustable and unregulated nature protection to constructions and the equipment and also without them, correspond as 1:4.9:83.5. It is shown that a ratio of costs of compensation of ecological damage in case of accidents on routes of the same sites of the oil pipeline equipped adjustable and unregulated nature protection to constructions and the equipment and also without them approximately correspond as 1:1.9:7.5.

scholarly journals DYNAMICS OF PNEUMATIC AND HYDRAULIC TRANSPORT TECHNOLOGICAL EQUIPMENT

Transport ◽  
2004 ◽  
Vol 19 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Marijonas Bogdevičius ◽  
Arvydas Matuliauskas ◽  
Vygantas Mištinas ◽  
Bronislovas Spruogis ◽  
Vladimiras Suslavičius
Keyword(s):  
Method Of Characteristics ◽  
Linear Part ◽  
Technological Equipment ◽  
Hydraulic Transport ◽  
Pneumatic Drive ◽  
Oil Pipeline ◽  
Continuity Equations ◽  
Oil Pipelines ◽  
Pressure Pipeline

In the article the classification of inpipe robots is presented, their advantages and imperfections are reviewed. The schemes of the construction of the wall press walking inpipe robot with a pneumatic drive and an inpipe robot with a vibratory pneumatic drive are given. The analysis of the identification method of leaks occurring due to damages of the linear part of the main oil pipelines is carried out. The momentum and continuity equations of viscous compressible fluid in a pressure pipeline are presented. Differential equations of fluid movement in the oil pipeline are solved by the method of characteristics. Variation diagrams of pressure and velocity of fluid in a leaking oil pipeline are presented. The impulsive extinguishing systems are presented.

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