Ensuring fire safety for autogas filling stations in town

2017 ◽  
pp. 49-59
Author(s):  
Roman Shavaliev ◽  
Rinat Yagudin ◽  
Daniil Valeev ◽  
Elena Elizareva ◽  
Roman Marvanov
Keyword(s):  
Practical Importance ◽  
Operating Conditions ◽  
Industrial Safety ◽  
Current Status ◽  
Process Equipment ◽  
Chain Growth ◽  
Case Scenario ◽  
Worst Case ◽  
Filling Station ◽  
Fire And Explosion

Objective: To ensure industrial safety for autogas filling stations operated in town, analyzing the current status of the issue and identifying accident causes are performed. Methods: It is shown that most motor vehicles are not designed to use liquefied gas as a fuel and consequently converted to fit gas cylinders for using liquefied petroleum gases (LPG) making the hazard to people much higher and contributing to autogas filling station chain growth. As the filling station process involves highly flammable gases, such facilities may be referred to as fire and explosion hazardous. Results: Making a selection of a typical autogas filling station based on systems analysis methods and also approved methods, an emergency is simulated with a gas-air mixture explosion in implementing a worst-case scenario (LPG escape resulting from a destroyed tank truck forming a primary gas-vapor cloud with the gas-air mixture exploding): injurious effects and potential impact are assessed. It is identified that within a 50 m radius there is a risk that people may be affected and also that buildings and structures placed in close vicinity to it be damaged, which causes a special threat if located close to other autogas filling stations. As one of the primary goals for safe operation of autogas filling stations is keeping rated operating conditions for process equipment components, a number of early preventive measures has to be taken, which would allow avoiding any emergencies. Practical importance: Following the patent study, a dusty cloud generation device based on an explosion overpressure triggering mechanism for explosion containment is contemplated and proposed and its location and operating conditions are recommended, which will make the facility better protected from fire and explosion hazards.

Major Hazards of Process Equipment Failures in the Chemical Process Industry

2015 ◽  
Vol 735 ◽  
pp. 75-79 ◽  
Author(s):  
N.E. Hussin ◽  
Anwar Johari ◽  
Kamarizan Kidam ◽  
Haslenda Hashim
Keyword(s):  
Chemical Process ◽  
Process Industry ◽  
Transportation Safety ◽  
Process Equipment ◽  
Case Scenario ◽  
Chemical Safety ◽  
Worst Case ◽  
Chemical Process Industry ◽  
Piping Systems ◽  
Equipment Failures

Process equipment failures play significant roles in most accidents that occur and recur in the chemical process industry resulting in fire, explosion, and toxic release. In this study, 50 equipment-related accident investigation reports were used to analyze type and severity of incidents. The comprehensive accident report data were retrieved from U.S. Chemical Safety and Hazard Investigation Board (CSB) and U.S. National Transportation Safety Board (NTSB) accident databases with a mean year of 2005. Among the identified process equipment failures were piping systems (32%), storage tanks (20%), process vessels (16%), separation equipment (10%), reactors (8%), heat transfer equipment (8%), and others (6%). The analysis shows that 32% of the cases led to fire and explosion, followed by toxic release (26%), and explosion (22%) incidents. A total of 126 fatalities, 590 injuries, 260 exposures, four shelter-in-place, and 13 evacuations were reported. In most accident cases, fire, explosion, and/or toxic release incidents occur simultaneously. The synergy between major hazards results in catastrophic accidents with severe consequences in numbers of fatalities, injuries, exposures, shelter-in-place, and evacuations. To minimize the losses, plant and equipment should be designed and prepared for the worst-case scenario, not just adapting to any ‘applicable’ standards or guidance.

Assessment of the numerical and experimental methodology to predict EGR cylinder-to-cylinder dispersion and pollutant emissions

2020 ◽  
pp. 146808742097254
Author(s):  
José Galindo ◽  
Héctor Climent ◽  
Roberto Navarro ◽  
Guillermo García-Olivas
Keyword(s):  
Operating Conditions ◽  
Experimental Methodology ◽  
Pollutant Emissions ◽  
Intake Manifold ◽  
Step Size ◽  
Case Scenario ◽  
Time Step ◽  
Worst Case ◽  
Time Step Size ◽  
Mean Square Errors

EGR cylinder-to-cylinder dispersion poses an important issue for piston engines, since it increases NOx and particulate matter (PM) emissions. In this work, the EGR distribution on a 6-cylinder intake manifold is analyzed by means of experiments, 0D/1D engine modeling and 3D CFD simulations at three different working points. Using a comprehensive set of measurements, statistical regressions for NOx and PM emissions are developed and employed to quantify the sensitivity of numerical configuration to EGR dispersion and subsequent increase of pollutants. CFD mesh and time-step size independence studies are conducted, taking into account their interrelation through the Courant number. The obtained numerical configuration is validated against experimental measurements, considering different unsteady RANS turbulence submodels ([Formula: see text] and [Formula: see text]) as well as the inviscid case. The agreement of the different approaches is quite sensitive to the operating conditions, obtaining root mean square errors for the average cylinder-to-cylinder EGR distribution between 1% and 17% and for the transient [Formula: see text] traces between 8% and 29%. However, for the worst-case scenario, the error in NOx and PM emissions prediction is below 2%. The regressions are employed to find a greater EGR distribution impact on pollutants when EGR rate or dispersion are increased. Flow investigation reveals the underlying reasons for the discrepancies and similarities between the predictions of the different turbulence submodels. A statistical analysis shows the significant errors that average [Formula: see text] probes make when assessing EGR cylinder-to-cylinder distribution, which is explain by the flow heterogeneity at some operating conditions.

LESSONS LEARNED FROM PROCESS EQUIPMENT FAILURES IN THE CHEMICAL PROCESS INDUSTRY

2015 ◽  
Vol 75 (6) ◽  
Author(s):  
Nor Afina Eidura Hussin ◽  
Kamarizan Kidam ◽  
Siti Suhaili Shahlan ◽  
Anwar Johari ◽  
Haslenda Hashim
Keyword(s):  
Communication Systems ◽  
Chemical Process ◽  
Lessons Learned ◽  
Process Industry ◽  
Process Equipment ◽  
Case Scenario ◽  
Chemical Safety ◽  
Worst Case ◽  
Chemical Process Industry ◽  
Equipment Failures

Process equipment failures play significant roles in most accidents that occur and recur in the chemical process industry (CPI). In this study, 50 equipment comprehensive accident investigation reports, extracted from the U.S. Chemical Safety and Hazard Investigation Board (CSB) and U.S. National Transportation Safety Board (NTSB) were analyzed to generate lessons learned. Based on the analysis, the synergy between major hazards i.e. fire, explosion, and toxic release has resulted in catastrophic accidents in the CPI. The emphasis on procedural equipment failure prevention does not provide sufficient hierarchy of controls in the CPI. Balance and integrated accident prevention is required to solve human unreliability that often leads to improper problem-solving, inappropriate actions, and ill-timed responses. To minimize losses, facilities and equipment should be designed and prepared for the worst-case scenario. Moreover, occurrence and recurrence of the accidents could be prevented using inclusive and updated communication systems through cooperation between various governmental agencies, industry players, and the public to disseminate lessons learned and promote safety in the industry. 

Computer modeling as tools to estimate the impact of fuel type on the capacity rating of lime kilns

TAPPI Journal ◽  
2015 ◽  
Vol 14 (7) ◽  
pp. 461-473
Author(s):  
J. PETER GOROG ◽  
W. RAY LEARY ◽  
DAVID WANG ◽  
KEVIN DAVIS
Keyword(s):  
Natural Gas ◽  
Paper Industry ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Fuel Type ◽  
Case Scenario ◽  
Modeling Tools ◽  
Worst Case ◽  
The Impact ◽  
Capacity Rating

In response to the drop in the price of natural gas, the U.S. pulp and paper industry has switched from using fuel oil to natural gas to fire kilns used to regenerate lime in the kraft process. While being financially attractive, replacing fuel oil with natural gas can be challenging. This is particularity true when the capacity rating is constrained by the temperatures of the gas exiting the kiln. In the worst case scenario, the increase in flue gas temperatures associated with switching from fuel oil to natural gas can significantly de-rate the capacity of the kiln. This paper describes a range of computational modeling tools that can be used to estimate the impacts of kiln geometry, fuel type, operating conditions, and burner design on kiln performance. Data taken from operating kilns is presented, which validates the use of these models. A detailed case study is presented showing how small amounts of torrefied wood can be co-fired with natural gas as a replacement for fuel oil without de-rating the capacity of the kiln. The visualization of the flow fields, temperature distributions, and species concentrations provided by computer models are critical to optimizing kiln operations as new fuels are being considered as replacements for more expensive, carbon intensive fuel oil.

The onset of transverse recirculations during flow of gases in horizontal ducts with differentially heated lower walls

1994 ◽  
Vol 277 ◽  
pp. 249-269 ◽  
Author(s):  
N. K. Ingle ◽  
T. J. Mountziaris
Keyword(s):  
Heat Transfer ◽  
Computational Study ◽  
Chemical Vapour ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Case Scenario ◽  
Worst Case ◽  
Layer Structures ◽  
Fluid Properties ◽  
Inlet Conditions

A computational study has been performed to identify the onset of transverse buoyancy-driven recirculations during laminar flow of hydrogen and nitrogen in horizontal ducts with cool upper walls, and lower walls consisting of three sections: a cool upstream section, a heated middle section and a cool downstream section. The motivation for this work stems from the need to identify operating conditions maximizing the thickness uniformity, the interface abruptness and the precursor utilization during growth of thin films and multi-layer structures of semiconductors by metalorganic chemical vapour deposition (MOCVD). A mathematical model describing the flow and heat transfer along the vertical midplane of MOCVD reactors with the above geometry has been developed and computer simulations were performed for a variety of operating conditions using the Galerkin finite-element method. At atmospheric pressure and low inlet velocities, transverse recirculations form near the upstream and downstream edges of the heated section. These can be suppressed either by increasing the inlet velocity of the gas, so that forced convection dominates natural convection, or by decreasing the operating pressure to reduce the effects of buoyancy. The onset of transverse recirculations has been determined for Grashof (Gr) and Reynolds (Re) numbers covering the following ranges: 10−3 < Re < 100 and 1 < Gr < 106, with Gr and Re computed using fluid properties at the inlet conditions. The computations indicate that, for abrupt temperature changes along the lower wall (worst-case scenario), transverse recirculations are always absent if the following criteria are satisfied: \[(Gr/Re) < 100\quad {\rm for}\quad 10^{-3} < Re \leqslant 4\quad {\rm and}\quad (Gr/Re^2) < 25\quad {\rm for}\quad 4 \leqslant Re < 100.\]The predicted critical values of Re, which correspond to the onset of transverse recirculations, agree well with reported experimental observations. The above criteria can be used for optimal design and operation of horizontal MOCVD reactors and may also be useful for heat transfer studies in horizontal ducts with differentially heated lower walls.

Reducing Probabilistic Weather Forecasts to the Worst Case Scenario: Anchoring Effects

2008 ◽  
Author(s):  
Sonia Savelli ◽  
Susan Joslyn ◽  
Limor Nadav-Greenberg ◽  
Queena Chen
Keyword(s):  
Case Scenario ◽  
Worst Case ◽  
Weather Forecasts ◽  
Worst Case Scenario ◽  
Anchoring Effects

EXPEDITION TO MALI, 2020

2020 ◽  
pp. 12-28
Author(s):  
D. V. Vaniukova ◽  
◽  
P. A. Kutsenkov ◽  
Keyword(s):  
Mass Murder ◽  
The State ◽  
Case Scenario ◽  
Worst Case ◽  
Traditional Art ◽  
Peter The Great ◽  
State Museum ◽  
Bobo Dioulasso ◽  
Oriental Studies ◽  
The Village

The research expedition of the Institute of Oriental studies of the Russian Academy of Sciences has been working in Mali since 2015. Since 2017, it has been attended by employees of the State Museum of the East. The task of the expedition is to study the transformation of traditional Dogon culture in the context of globalization, as well as to collect ethnographic information (life, customs, features of the traditional social and political structure); to collect oral historical legends; to study the history, existence, and transformation of artistic tradition in the villages of the Dogon Country in modern conditions; collecting items of Ethnography and art to add to the collection of the African collection of the. Peter the Great Museum (Kunstkamera, Saint Petersburg) and the State Museum of Oriental Arts (Moscow). The plan of the expedition in January 2020 included additional items, namely, the study of the functioning of the antique market in Mali (the “path” of things from villages to cities, which is important for attributing works of traditional art). The geography of our research was significantly expanded to the regions of Sikasso and Koulikoro in Mali, as well as to the city of Bobo-Dioulasso and its surroundings in Burkina Faso, which is related to the study of migrations to the Bandiagara Highlands. In addition, the plan of the expedition included organization of a photo exhibition in the Museum of the village of Endé and some educational projects. Unfortunately, after the mass murder in March 2019 in the village of Ogossogou-Pel, where more than one hundred and seventy people were killed, events in the Dogon Country began to develop in the worst-case scenario: The incessant provocations after that revived the old feud between the Pel (Fulbe) pastoralists and the Dogon farmers. So far, this hostility and mutual distrust has not yet developed into a full-scale ethnic conflict, but, unfortunately, such a development now seems quite likely.

Risk-Based Robust Bidding Strategies for EVs’ Aggregators in Day-ahead Markets with Uncertainty

2020 ◽  
Author(s):  
Ahmed Abdelmoaty ◽  
Wessam Mesbah ◽  
Mohammad A. M. Abdel-Aal ◽  
Ali T. Alawami
Keyword(s):  
Robust Optimization ◽  
Electricity Market ◽  
Real Life ◽  
Optimization Approach ◽  
Case Scenario ◽  
Worst Case ◽  
Bidding Strategies ◽  
Wind Generators ◽  
Proposed Model ◽  
Optimal Bidding

In the recent electricity market framework, the profit of the generation companies depends on the decision of the operator on the schedule of its units, the energy price, and the optimal bidding strategies. Due to the expanded integration of uncertain renewable generators which is highly intermittent such as wind plants, the coordination with other facilities to mitigate the risks of imbalances is mandatory. Accordingly, coordination of wind generators with the evolutionary Electric Vehicles (EVs) is expected to boost the performance of the grid. In this paper, we propose a robust optimization approach for the coordination between the wind-thermal generators and the EVs in a virtual<br>power plant (VPP) environment. The objective of maximizing the profit of the VPP Operator (VPPO) is studied. The optimal bidding strategy of the VPPO in the day-ahead market under uncertainties of wind power, energy<br>prices, imbalance prices, and demand is obtained for the worst case scenario. A case study is conducted to assess the e?effectiveness of the proposed model in terms of the VPPO's profit. A comparison between the proposed model and the scenario-based optimization was introduced. Our results confirmed that, although the conservative behavior of the worst-case robust optimization model, it helps the decision maker from the fluctuations of the uncertain parameters involved in the production and bidding processes. In addition, robust optimization is a more tractable problem and does not suffer from<br>the high computation burden associated with scenario-based stochastic programming. This makes it more practical for real-life scenarios.<br>

scholarly journals A Thermally Conductive Pt/AAO Catalyst for Hydrogen Passive Autocatalytic Recombination

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 491
Author(s):  
Alina E. Kozhukhova ◽  
Stephanus P. du Preez ◽  
Aleksander A. Malakhov ◽  
Dmitri G. Bessarabov
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Combustion Temperature ◽  
Volume Fraction ◽  
Morphological Characteristics ◽  
Al Alloy ◽  
Impregnation Method ◽  
Case Scenario ◽  
Worst Case ◽  
Thermal Distribution

In this study, a Pt/anodized aluminum oxide (AAO) catalyst was prepared by the anodization of an Al alloy (Al6082, 97.5% Al), followed by the incorporation of Pt via an incipient wet impregnation method. Then, the Pt/AAO catalyst was evaluated for autocatalytic hydrogen recombination. The Pt/AAO catalyst’s morphological characteristics were determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average Pt particle size was determined to be 3.0 ± 0.6 nm. This Pt/AAO catalyst was tested for the combustion of lean hydrogen (0.5–4 vol% H2 in the air) in a recombiner section testing station. The thermal distribution throughout the catalytic surface was investigated at 3 vol% hydrogen (H2) using an infrared camera. The Al/AAO system had a high thermal conductivity, which prevents the formation of hotspots (areas where localized surface temperature is higher than an average temperature across the entire catalyst surface). In turn, the Pt stability was enhanced during catalytic hydrogen combustion (CHC). A temperature gradient over 70 mm of the Pt/AAO catalyst was 23 °C and 42 °C for catalysts with uniform and nonuniform (worst-case scenario) Pt distributions. The commercial computational fluid dynamics (CFD) code STAR-CCM+ was used to compare the experimentally observed and numerically simulated thermal distribution of the Pt/AAO catalyst. The effect of the initial H2 volume fraction on the combustion temperature and conversion of H2 was investigated. The activation energy for CHC on the Pt/AAO catalyst was 19.2 kJ/mol. Prolonged CHC was performed to assess the durability (reactive metal stability and catalytic activity) of the Pt/AAO catalyst. A stable combustion temperature of 162.8 ± 8.0 °C was maintained over 530 h of CHC. To confirm that Pt aggregation was avoided, the Pt particle size and distribution were determined by TEM before and after prolonged CHC.

scholarly journals A Comparison of Match Demands Using Ball-in-Play versus Whole Match Data in Professional Soccer Players of the English Championship

Sports ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 76
Author(s):  
Dylan Mernagh ◽  
Anthony Weldon ◽  
Josh Wass ◽  
John Phillips ◽  
Nimai Parmar ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Soccer Players ◽  
Training Methods ◽  
Case Scenario ◽  
Worst Case ◽  
Repeated Measures Design ◽  
Worst Case Scenario ◽  
Professional Soccer ◽  
Peak Match ◽  
Playing Time

This is the first study to report the whole match, ball-in-play (BiP), ball-out-of-play (BoP), and Max BiP (worst case scenario phases of play) demands of professional soccer players competing in the English Championship. Effective playing time per soccer game is typically <60 min. When the ball is out of play, players spend time repositioning themselves, which is likely less physically demanding. Consequently, reporting whole match demands may under-report the physical requirements of soccer players. Twenty professional soccer players, categorized by position (defenders, midfielders, and forwards), participated in this study. A repeated measures design was used to collect Global Positioning System (GPS) data over eight professional soccer matches in the English Championship. Data were divided into whole match and BiP data, and BiP data were further sub-divided into different time points (30–60 s, 60–90 s, and >90 s), providing peak match demands. Whole match demands recorded were compared to BiP and Max BiP, with BiP data excluding all match stoppages, providing a more precise analysis of match demands. Whole match metrics were significantly lower than BiP metrics (p < 0.05), and Max BiP for 30–60 s was significantly higher than periods between 60–90 s and >90 s. No significant differences were found between positions. BiP analysis allows for a more accurate representation of the game and physical demands imposed on professional soccer players. Through having a clearer understanding of maximum game demands in professional soccer, practitioners can design more specific training methods to better prepare players for worst case scenario passages of play.

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