scholarly journals Analysis of the use of transformable elements in intelligent tunnel ventilation systems

2022 ◽  
Vol 354 ◽  
pp. 00020
Author(s):  
Omar Lanchava ◽  
Nicolae Ilias ◽  
Sorin Mihai Radu ◽  
Giorgi Nozadze ◽  
David Tsanava
Keyword(s):  
Numerical Models ◽  
Ventilation System ◽  
Aerodynamic Resistance ◽  
Combustion Products ◽  
Underground Space ◽  
Centralized Control ◽  
Safe Operation ◽  
Auxiliary Equipment ◽  
Air Masses ◽  
Initial Stage

All main and auxiliary equipment in the tunnel with an intelligent ventilation system are designed to ensure the safety. These systems “talk” and “listen” to each other, make decisions to switch on/off certain system(s) or part(s) thereof and duly inform the tunnel operator, who is authorized to the centralized control of all systems of necessity. The present article uses the numerical models to assess the efficiency of the transformable elements ensuring safe operation of the tunnels. The idea of their use is based on an artificial increase of the tunnel aerodynamic resistance by means of a flexible element, which will hamper the dissemination of combustion products, but not the movement of people through the tunnel and will help isolate clean and polluted air masses. Such resistance will be used to swiftly divide the tunnel carriageway into smaller sections what will help extinguish the fire as early as at its initial stage, prolong the evacuation time and save lives during the strong uncontrollable fires. As for the compact transformable element, it can be used in both, the operating and the planned tunnels, as it in practice does not reduce the volume of valuable underground space.

Air Flow Straighteners’ Application to Reduce the Power Consumption of Exhaust Ventilation Schemes

2018 ◽  
Vol 875 ◽  
pp. 137-140 ◽  
Author(s):  
Valery N. Azarov ◽  
Natalia M. Sergina ◽  
I.V. Stefanenko
Keyword(s):  
Power Consumption ◽  
Air Flow ◽  
Ventilation System ◽  
Aerodynamic Resistance ◽  
Experimental Studies ◽  
Swirling Flows ◽  
Dust Collector ◽  
Exhaust Ventilation ◽  
Outlet Pipe ◽  
Ventilation Systems

It was proposed to use air flow screw straightened units in outlet pipe of the dust collectors to reduce the aerodynamic resistance of exhaust ventilation systems. It is allowed to decrease power consumption for their maintenance operation consequently. The article describes the results of experimental studies to evaluate its effectiveness by applying the tangential screw straightened unit within ventilation system. The obtained results showed that the use of this device allows reducing the aerodynamic resistance of the cyclone by 14.6%, and for counter-swirling flows’ dust collector (CSFC) by 17.2-23.6%. It was found that meanings of the aerodynamic resistance depend on value the share proportion of the flow entering into lower CSFC apparatus’ input.

Gasified boiler units

2021 ◽  
Author(s):  
Vyacheslav Kuznecov ◽  
Oleg Bryuhanov
Keyword(s):  
Vocational Education ◽  
Thermal Control ◽  
Combustion Products ◽  
Hot Water ◽  
Automatic Regulation ◽  
Federal State ◽  
Auxiliary Equipment ◽  
Secondary Vocational Education ◽  
Supply Systems ◽  
Gas Supply

The textbook gives the basic concepts of gasified heat generating (boiler) installations and the terminology used in boiler technology, the principle of operation and device of gasified heat generating (boiler) installations. The types and device of heat generators (boilers) of their furnace devices are considered; types and device of gas-burning devices, the number and places of their installation in furnace devices; auxiliary equipment-devices for air supply and removal of combustion products, devices for water treatment, steam supply and circulation of the coolant of hot water boilers; device for thermal control and automatic regulation of the boiler installation. The issues of operation and efficiency of gasified heat generating (boiler) installations and their gas supply systems; requirements for conducting gas-hazardous and emergency recovery operations of gas supply systems are considered. Meets the requirements of the federal state educational standards of secondary vocational education of the latest generation. For students of secondary vocational education in the specialty 08.02.08 "Installation and operation of equipment and gas supply systems".

Delineation of Wellhead Protection Areas: Theory and Practice

1991 ◽  
Vol 24 (11) ◽  
pp. 239-250 ◽  
Author(s):  
Tereza C. B. F. Cleary ◽  
Robert W. Cleary
Keyword(s):  
United States ◽  
Groundwater Protection ◽  
Numerical Models ◽  
The United States ◽  
Pollution Sources ◽  
Theory And Practice ◽  
Safe Operation ◽  
Wellhead Protection ◽  
Protection Area ◽  
Potential Pollution

A preventive approach in groundwater protection programs throughout Europe and the United States, and almost unknown in Brazil, is to define the surface and subsurface areas, the Wellhead Protection Area (WHPA), from which a well or wellfield draws its water during a specified time. Overlaying a map of potential pollution sources on the delineated WHPA (Figure 1), those sources which fall within the WHPA boundaries are identified as definite threats, that need to be closely monitored, to the continued safe operation of the wellfield. Given the importance of effectively delineating the WHPA to protect public water supplies, the current delineation criteria, methods, and zones are presented, as well as analytical and numerical PC model analyses of different hydrogeological scenarios' effects on WHPA's size, shape and direction. Numerical models are shown to more accurately define WHPAs by taking into account the surrounding heterogeneous and anisotropic geology.

OPTIMIZING THE CHOICE OF VENTILATING AIR CLEANING EQUIPMENT IN SYSTEMS OF LOCAL EXHAUST VENTILATION

2017 ◽  
Vol 7 (3) ◽  
pp. 19-23
Author(s):  
Svetlana M. PURING ◽  
Denis N. VATUZOV ◽  
Gennady I. TITOV
Keyword(s):  
Indoor Air ◽  
Desirability Function ◽  
Ventilation System ◽  
Aerodynamic Resistance ◽  
Multicriteria Analysis ◽  
Local Exhaust Ventilation ◽  
Air Cleaning ◽  
Exhaust Ventilation ◽  
Industrial Buildings ◽  
Cleaning Equipment

Functioning of industrial buildings is impossible without correctly organized ventilation system. Its work both regulates heat moist mode and the required indoor air purity that is cleaned with the help of air cleaning equipment. To make decision to construct the required air cleaning equipment at the enterprise it is worthwhile to give additional parameters and to solve a problem of multicriteria optimization to get the best results. The choice of the best variant is supposed to be carried out using Harrington’s desirability function. The conducted multicriteria analysis allowed to reveal optimum characteristics of air cleaning equipment, based on the required purifi cation air degree, the geometrical sizes of the equipment and aerodynamic resistance while introducing any particular device.

scholarly journals Numerical 3D Simulation of a Longitudinal Ventilation System: Memorial Tunnel Case

2006 ◽  
Author(s):  
Monica Galdo-Vega ◽  
Rafael Ballesteros-Tajadura ◽  
Carlos Santolaria-Morros
Keyword(s):  
Numerical Models ◽  
Ventilation System ◽  
Fire Behavior ◽  
Full Scale ◽  
3D Simulation ◽  
Full Scale Test ◽  
Road Tunnel ◽  
Tunnel Fire ◽  
Longitudinal Ventilation ◽  
Scale Test

In this work, a numerical 3D simulation of a longitudinal ventilation system is developed to analyze the fire behavior inside a road tunnel. Recent disasters, like crashes in the Mont Blanc tunnel (France, 1999) or San Gottardo (Italy, 2001), have shown the need for better integral actions during possible fire incidents. The minimum delay time, required for starting the jet fans, or the evolution of the smoke patterns inside the tunnel are critical issues when rescue plans are designed. Some methods to study the smoke propagation during a fire are: pseudo-thermal scale models, full scale test and numerical models. Several contributions using the first method can be found in references [1], [2] and [3]. However it is very difficult to extrapolate the results from this kind of models. The second method (full scale test) is the most expensive of all and only two of them have been conducted recently: EUREKA Project [4] and the Memorial Tunnel Fire Ventilation Test Program [5]. The last method (numerical models) it is now under development. The objective of this work is to validate a numerical model, to predict the behavior of the smoke generated during a fire incident inside a road tunnel, comparing its results with previous experimental data collected in the Memorial Tunnel Project. In addition, a good agreement was achieved, so a methodology to predict the performance of a longitudinal ventilation system in case of fire was accurately established.

scholarly journals Influence of Wind on Air Movement in a Free-Stall Barn During the Summer Period / Wpływ wiatru na ruch powietrza w oborze wolnostanowiskowej w okresie letnim

2013 ◽  
Vol 13 (1) ◽  
pp. 109-119 ◽  
Author(s):  
Piotr Herbut ◽  
Sabina Angrecka ◽  
Grzegorz Nawalany
Keyword(s):  
Natural Ventilation ◽  
Air Flow ◽  
Ventilation System ◽  
Air Velocity ◽  
Summer Period ◽  
Air Masses ◽  
Air Movement ◽  
Microclimatic Conditions ◽  
Hot Weather ◽  
Different Levels

Abstract Use of natural ventilation in the barn should lead to optimal microclimatic conditions over the entire space. In the summer, especially during hot weather, higher air velocity cools cows, which helps to avoid heat stress. The paper presents the results of studies on the evolution of air movement in a modernized free-stall barn of the Fermbet type with the natural ventilation system during the summer period. Based on measurements of velocity and direction of air flow (inside and outside the barn) and observations of smoke indicator, the movement of air masses in different parts of the barn was identified. Significant variations of air flow at different levels of the barn were found. These differences deviate from the accepted patterns of natural ventilation, which can be found in the literature. The range of a draught and stagnant air along with the conditions in which they are built was determined. On this basis, recommendations regarding the location of barns on the plots and the improvement of ventilation in summer were made.

scholarly journals ESTIMATION OF AMOUNT CHANGING OF LOCAL AERODYNAMIC RESISTANCE OF ELEMENTS OF VENTILATION SYSTEM OF MINE AT REVERSING BEHAVIOR OF VENTILATION SYSTEM

2019 ◽  
Vol 2 (4) ◽  
pp. 212-219
Author(s):  
Stanislav Pavlov
Keyword(s):  
Ventilation System ◽  
Aerodynamic Resistance ◽  
Mine Ventilation ◽  
Ventilation Network ◽  
Work Study ◽  
Finite Element Software ◽  
Emergency Ventilation ◽  
Study Results ◽  
Aerodynamic Parameters ◽  
Junction Angle

In the work study results of influence of typical working junction angle on amount changing of local aerodynamic resistances when air flows in different directions is represented. Using finite-element software, aerodynamic parameters of elements of mine ventilation network is obtained and is compared with analytical calculations Interinfluence local aerodynamic resistances located at ventilation network consecutively in normal and reversing behavior is discovered. It allows to increase accuracy of calculation of mine ventilation network at emergency ventilation operation.

scholarly journals Identification of zones of influence of exogenous fire damaging factors

2020 ◽  
Vol 168 ◽  
pp. 00049
Author(s):  
Ivan Kokoulin ◽  
Tetiana Bunko ◽  
Ihor Yashchenko ◽  
Ruslan Papirnyk ◽  
Anatolii Belikov ◽  
...  
Keyword(s):  
Mine Ventilation ◽  
Combustion Products ◽  
Emergency Evacuation ◽  
Dynamic State ◽  
Ventilation Network ◽  
Ventilation Mode ◽  
Air Stream ◽  
Initial Stage ◽  
Accident Response ◽  
Gas Recirculation

In this work, topological configuration of dangerous zone in the mine ventilation network and concentrations of fire gases in it are estimated and identified at vent impacting on the emergency conditions. The obtained information on gas-dynamic state of the mine ventilation network at a current moment of time is used for undertaking primary measures according to the plan of accident response: emergency evacuation of people and actions of militarized mine-rescue services for eliminating emergency at its initial stage with taking into account changed emergency ventilation mode. The proposed method allows identifying an area in the mine contaminated by combustion products with taking into account time of its formation, changes in ventilation mode during the accident and possible air stream reversal in zones with descentional ventilation under the influence of the fire source depression and formation of zones with fire gas recirculation. With implementation of this method, it becomes possible to improve accuracy of detecting gassy zones in the ventilation network and effectiveness of emergency response.

scholarly journals Determination of Parameters Describing the Risk Areas of Ships Chaotic Rolling on the Example of LNG Carrier and OSV Vessel

2020 ◽  
Vol 8 (2) ◽  
pp. 91 ◽  
Author(s):  
Sambor Guze ◽  
Wojciech Wawrzynski ◽  
Przemyslaw Wilczynski
Keyword(s):  
Degrees Of Freedom ◽  
Numerical Models ◽  
Nonlinear Differential Equations ◽  
Design Stage ◽  
Safe Operation ◽  
Ship Model ◽  
Risk Areas ◽  
Determination Of Parameters ◽  
The Mathematical Model

One of the significant problems in the safe operation of vessels is the behavior of the ship on the wave. Of all degrees of freedom, the greatest threat to the safety of a ship is associated with excessive rolling. One of the best methods to improve the safety of a ship in this field is to carry out experiments on the ship model, performed at her design stage. The problem is that the model tests are costly. An alternative is to conduct simulation tests based on numerical models. The primary goal of the article is to present the results of the simulation regarding the determination of parameters describing the risk areas of chaotic rolling for the ship designed for transporting liquefied natural gas (LNG carrier) and offshore support vessel (OSV). The first discusses the state of knowledge on mathematical modeling of oscillations. Then, the theory of nonlinear differential equations is presented, and the mathematical model of ship rolling is described. This model is used to prepare and conduct a numerical simulation in the Mathematica package. The results of these studies and their discussion constitute the central part of the article. Finally, the conclusions are presented.

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