WorldWideScience

Sample records for analysis fire simulation

  1. Sensitivity Analysis of Fire Dynamics Simulation

    DEFF Research Database (Denmark)

    Brohus, Henrik; Nielsen, Peter V.; Petersen, Arnkell J.; Sommerlund-Larsen, Kim

    2007-01-01

    In case of fire dynamics simulation requirements to reliable results are most often very high due to the severe consequences of erroneous results. At the same time it is a well known fact that fire dynamics simulation constitutes rather complex physical phenomena which apart from flow and energy...... equations require solution of the issues of combustion and gas radiation to mention a few. This paper performs a sensitivity analysis of a fire dynamics simulation on a benchmark case where measurement results are available for comparison. The analysis is performed using the method of Elementary Effects...... (Morris method). The parameters considered are selected among physical parameters and program specific parameters. The influence on the calculation result as well as the CPU time is considered. It is found that the result is highly sensitive to many parameters even though the sensitivity varies...

  2. Simulation analysis of the spread of fire through the program Fire Dynamics Simulator FDS in areas of fire of nuclear power plants

    International Nuclear Information System (INIS)

    The objective of the analysis of the spread of fire through Computational Fluid Dynamics simulation with the Fire Dynamics Simulator program is to determine the identification of the affected computers and determine the livability in the areas of fire as fire postulates. The simulation with Fire Dynamics Simulator allows the evolution and spread of flame and smoke behavior in an instant in time, determining the exact moment that damage is caused by radiation or temperature to equipment and operation according to the level of toxicity and temperature of the fire area. (Author)

  3. LNG pool fire simulation for domino effect analysis

    International Nuclear Information System (INIS)

    A three-dimensional computational fluid dynamics (CFD) simulation of liquefied natural gas (LNG) pool fire has been performed using ANSYS CFX-14. The CFD model solves the fundamental governing equations of fluid dynamics, namely, the continuity, momentum and energy equations. Several built-in sub-models are used to capture the characteristics of pool fire. The Reynolds-averaged Navier–Stokes (RANS) equation for turbulence and the eddy-dissipation model for non-premixed combustion are used. For thermal radiation, the Monte Carlo (MC) radiation model is used with the Magnussen soot model. The CFD results are compared with a set of experimental data for validation; the results are consistent with experimental data. CFD results show that the wind speed has significant contribution on the behavior of pool fire and its domino effects. The radiation contours are also obtained from CFD post processing, which can be applied for risk analysis. The outcome of this study will be helpful for better understanding of the domino effects of pool fire in complex geometrical settings of process industries. - Highlights: • Simulation of pool fire using computational fluid dynamics (CFD) model. • Integration of CFD based pool fire model with domino effect. • Application of the integrated CFD based domino effect analysis

  4. Probabilistic fire simulator - Monte Carlo simulation tool for fire scenarios

    International Nuclear Information System (INIS)

    Risk analysis tool is developed for computing of the distributions of fire model output variables. The tool, called Probabilistic Fire Simulator, combines Monte Carlo simulation and CFAST two-zone fire model. In this work, it is used to calculate failure probability of redundant cables and fire detector activation times in a cable tunnel fire. Sensitivity of the output variables to the input variables is calculated in terms of the rank order correlations. (orig.)

  5. Optimization of investment economic in PCI using the methodology of benefits design in analysis of the spread of fires with FDS (Fire Dynamics Simulator) in areas of nuclear fire

    International Nuclear Information System (INIS)

    Fire simulation analysis allows knowing the evolution and spread fire in areas of interest within a NPP such as control room, cable room and multi zone comportment among others. fires are a main concern regarding safety analysis of NPP. IDOM has the capability to carry out fire simulations, taken in to account smoke control, fire spread, toxicity levels, ventilation and all physical phenomena. As a result, appropriate fire protection measures can be assessed in each scenario. CFD tools applied to fire simulations can determine with higher resolution all damages caused during the fire. Furthermore, such tools can reduce costs due to a lower impact of design modifications. (Author)

  6. Optimization of investment economic in PCI using the methodology of benefits design in analysis of the spread of fires with FDS (Fire Dynamics Simulator) in areas of nuclear fire; Optimizacion de la inversion economica en PCI mediante la metodologia de diseo prestaional en el analisis de la propagacion de incendios con FDS (Fire Dynnamics Simulator) en areas de fuego de centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Salellas, J.

    2015-07-01

    Fire simulation analysis allows knowing the evolution and spread fire in areas of interest within a NPP such as control room, cable room and multi zone comportment among others. fires are a main concern regarding safety analysis of NPP. IDOM has the capability to carry out fire simulations, taken in to account smoke control, fire spread, toxicity levels, ventilation and all physical phenomena. As a result, appropriate fire protection measures can be assessed in each scenario. CFD tools applied to fire simulations can determine with higher resolution all damages caused during the fire. Furthermore, such tools can reduce costs due to a lower impact of design modifications. (Author)

  7. Simulation analysis of the spread of fire through the program Fire Dynamics Simulator FDS in areas of fire of nuclear power plants; Analisis de simulacion de la propagacion de incendios mediante el programa Fire Dynamics Simulator FDS en areas de fuego de Centrales Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Salellas, J.; Zamora, I.; Fabbri, M.; Colomer, C.; Castillo, R.; Fradera, J.

    2014-07-01

    The objective of the analysis of the spread of fire through Computational Fluid Dynamics simulation with the Fire Dynamics Simulator program is to determine the identification of the affected computers and determine the livability in the areas of fire as fire postulates. The simulation with Fire Dynamics Simulator allows the evolution and spread of flame and smoke behavior in an instant in time, determining the exact moment that damage is caused by radiation or temperature to equipment and operation according to the level of toxicity and temperature of the fire area. (Author)

  8. Design of experiment analysis for the Joint Dynamic Allocation of Fires and Sensors (JDAFS) simulation

    OpenAIRE

    Freye, Jeffrey T.

    2007-01-01

    The U.S. Army Training and Doctrine Command (TRADOC) Analysis Center's Joint Dynamic Allocation of Fires and Sensors (JDAFS) model, a low-resolution, Discrete Event Simulation Model with embedded optimization enables the analysis of many scenarios and factors to explore Joint Intelligence, Surveillance, and Reconnaissance (ISR) missions. JDAFS is a powerful model that combines both discrete event simulation and the optimization of a linear objective function to generate realistic, reasonable...

  9. Fire risk analysis, fire simulation, fire spreading and impact of smoke and heat on instrumentation electronics - State-of-the-Art Report

    International Nuclear Information System (INIS)

    Numerous fire PSAs (probabilistic safety assessments) have shown that fire can be a major contributor to nuclear power plant risk. However, there are considerable uncertainties in the results of these assessments, due to significant gaps in current abilities to perform realistic assessments. These gaps involve multiple aspects of fire PSA, including the estimation of the probability of important fire scenarios, the modeling of fire growth and suppression, the prediction of fire-induced damage to equipment (including the effects of smoke), and the treatment of plant and operator responses to the fire. In response to recommendations of /VIR 93/, CSNI/PWG5 established a Task Group to review the present status and maturity of current methods used in fire risk assessments for operating nuclear power plants. The Task Group issued a questionnaire in May 1997 to all nuclear power generating OECD countries. The prime focus of the questionnaire (see Appendix A) was on a number of important issues in fire PSA: Fire PSA methodology and applications; Fire simulation codes; Ignition and damageability data; Modeling of fire spread on cables or other equipment; Modeling of smoke production and spread; Impact of smoke and heat on instrumentation, electronics, or other electrical equipment; Impact of actual cable fires on safety systems. The questionnaire requested specific information on these topics (e.g., computer codes used in fire PSAs, the physical parameters used to model ignition). Responses to the questionnaire were provided by Finland, France, Germany, Hungary, Japan, Spain, Switzerland, United Kingdom, and the USA. This report summarizes the questionnaire responses and thereby: a) provides a perspective on the current fire PSA state of the art (SOAR) with respect to the issues listed above, and b) provides numerous references for more detailed information regarding these issues. The main responsibility for writing different chapters of this report was divided between some

  10. Computer simulations of a generic truck cask in a regulatory fire using the Container Analysis Fire Environment (CAFE) code

    International Nuclear Information System (INIS)

    The Container Analysis Fire Environment (CAFE) computer code is designed to predict accurately convection and radiation heat transfer to a thermally massive object engulfed in a large pool fire. It is well suited for design and risk analyses of spent nuclear fuel transport systems. CAFE employs computational fluid dynamics and several fire and radiation models. These models must be benchmarked using experimental results. In this paper, a set of wind velocity conditions are determined which allow CAFE accurately to reproduce recent heat transfer measurements for a thick walled calorimeter in a ST-1 regulatory pool fire. CAFE is then used to predict the response of an intack (thin walled) generic legal weight truck cask. The maximum temperatures reached by internal components are within safe limits. A simple 800 deg. C, grey-radiation fire model gives maximum component temperatures that are somewhat below those predicted by CAFE. (author)

  11. CERN Fire Brigade rescue simulation

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The CERN Fire Brigade is made up of experienced firemen from all of the 20 Member States. In these images they are seen at a 'Discovery Monday' held at the Microcosm exhibition. Here visitors learn how the Fire Brigade deal with various situations, including a simulated cave rescue performed by the Hazardous Environments Response Team.

  12. Simulating Building Fires for Movies

    Science.gov (United States)

    Rodriguez, Ricardo C.; Johnson, Randall P.

    1987-01-01

    Fire scenes for cinematography staged at relatively low cost in method that combines several existing techniques. Nearly realistic scenes, suitable for firefighter training, produced with little specialized equipment. Sequences of scenes set up quickly and easily, without compromising safety because model not burned. Images of fire, steam, and smoke superimposed on image of building to simulate burning of building.

  13. Risk Assessment of the Main Control Room Fire Using Fire Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dae Il; Kim, Kilyoo; Jang, Seung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    KAERI is performing a fire PSA for a reference plant, Ulchin Unit 3, as part of developing the Korean site risk profile (KSRP). Fire simulations of the MCR fire were conducted using the CFAST (Consolidated Fire Growth and Smoke Transport) model and FDS (fire dynamic simulator) to improve the uncertainty in the MCR fire risk analysis. Using the fire simulation results, the MCR abandonment risk was evaluated. Level 1 PSA (probabilistic safety assessment) results of Ulchin Unit 3 using the EPRI PRA (probabilistic risk assessment) implementation guide showed that the MCR (main control room) fire was the main contributor to the core damage frequency. Recently, U. S. NRC and EPRI developed NUREG/CR-6850 to provide state-of-the-art methods, tools, and data for the conduct of a fire PSA for a commercial NPP.

  14. Risk Assessment of the Main Control Room Fire Using Fire Simulations

    International Nuclear Information System (INIS)

    KAERI is performing a fire PSA for a reference plant, Ulchin Unit 3, as part of developing the Korean site risk profile (KSRP). Fire simulations of the MCR fire were conducted using the CFAST (Consolidated Fire Growth and Smoke Transport) model and FDS (fire dynamic simulator) to improve the uncertainty in the MCR fire risk analysis. Using the fire simulation results, the MCR abandonment risk was evaluated. Level 1 PSA (probabilistic safety assessment) results of Ulchin Unit 3 using the EPRI PRA (probabilistic risk assessment) implementation guide showed that the MCR (main control room) fire was the main contributor to the core damage frequency. Recently, U. S. NRC and EPRI developed NUREG/CR-6850 to provide state-of-the-art methods, tools, and data for the conduct of a fire PSA for a commercial NPP

  15. G-fire station : fire simulation from desktop to grid

    OpenAIRE

    Pina, António Manuel Silva; Marques, Ricardo; De Oliveira, Bruno,

    2009-01-01

    CROSS-Fire is a research project, funded by the Portuguese NGI and led by UMinho, and focused on topics related to decision making to control forest fires and on the porting to the grid of FireStation - a fire growth simulation application. G-FireStation exploits Grid capabilities in order to have a faster execution, to manage large data input/output files, to create a large data base of simulation results and to allow the interactive control of the simulations through a g...

  16. Deterministic analysis of mid scale outdoor fire

    International Nuclear Information System (INIS)

    The idea behind the article is how to define fire behaviour. The work is based on an analytical study of fire origin, its development and spread. Mathematical fire model called FDS (Fire Dynamic Simulator) is used in the presented work. A CFD (Computational Fluid Dynamic) model using LES (Large Eddie Simulation) is used to calculate fire development and spread of combustion products in the environment. The fire source is located in the vicinity of the hazardous plant, power, chemical etc. The article presents the brief background of the FDS computer program and the initial and boundary conditions used in the mathematical model. Results discuss output data and check the validity of results. The work also presents some corrections of the physical model used, which influence the quality of results. The obtained results were discussed and compared with the Fire Safety Analysis report included in the Probabilistic Safety Assessment of Krsko nuclear power plant. (author)

  17. Computer simulation of the fire-tube boiler hydrodynamics

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.

    2015-01-01

    Full Text Available Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

  18. Computer simulation of the fire-tube boiler hydrodynamics

    OpenAIRE

    Khaustov Sergei A.; Zavorin Alexander S.; Buvakov Konstantin V.; Sheikin Vyacheslav A.

    2015-01-01

    Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

  19. FIRE HAZARDS ANALYSIS - BUSTED BUTTE

    International Nuclear Information System (INIS)

    The purpose of this fire hazards analysis (FHA) is to assess the risk from fire within individual fire areas at the Busted Butte Test Facility and to ascertain whether the DOE fire safety objectives are met. The objective, identified in DOE Order 420.1, Section 4.2, is to establish requirements for a comprehensive fire and related hazards protection program for facilities sufficient to minimize the potential for: (1) The occurrence of a fire related event. (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees. (3) Vital DOE programs suffering unacceptable interruptions as a result of fire and related hazards. (4) Property losses from a fire and related events exceeding limits established by DOE. Critical process controls and safety class systems being damaged as a result of a fire and related events

  20. Theoretical analysis and numerical simulation on behaviour properties of large span cable-supported structures under fire conditions

    Institute of Scientific and Technical Information of China (English)

    BAI Yin; SHI YongJiu; WANG YuanQing

    2009-01-01

    Large span cable-supported structures have been developed rapidly in China,and they always adopt high-strength steel cables as structural members.However,the modulus of elasticity and yield strength of steel material will decrease seriously under fire conditions while fire protection is unlikely to be provided for steel cable.Several typical large span cable-supported structures such as cable truss,beam string structure and prestressed cable net are studied on their structural behaviour in this paper.Theoretical formulae are derived in terms of geometrical and material nonlinearity with high temperature effect.Finite element models are also established to simulate the structural performance under fire conditions.The calculation formulae for fire-resisting design are suggested for these three types of structures,while displacement and prestressed force variation rules are also given.

  1. Theoretical analysis and numerical simulation on behaviour properties of large span cable-supported structures under fire conditions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Large span cable-supported structures have been developed rapidly in China, and they always adopt high-strength steel cables as structural members. However, the modulus of elasticity and yield strength of steel material will decrease seriously under fire conditions while fire protection is unlikely to be provided for steel cable. Several typical large span cable-supported structures such as cable truss, beam string structure and prestressed cable net are studied on their structural behaviour in this paper. Theoretical formulae are derived in terms of geometrical and material nonlinearity with high temperature effect. Finite element models are also established to simulate the structural performance under fire conditions. The calculation formulae for fire-resisting design are suggested for these three types of structures, while displacement and prestressed force variation rules are also given.

  2. Analysis of the large urban fire environment

    International Nuclear Information System (INIS)

    An analysis describing the high temperature and velocity environment of a large urban area fire is presented. The boundary value problem treats the burning region in detail. A novel prescription of the boundary conditions at the fire periphery allows the burning-region analysis to be uncoupled from analyses of the free-convection column and the far field. The relationship between burning rate, buoyancy, pressure gradients, and the creation of high velocity fire winds is described. Sample results simulate the burning-region environment for the 1943 Hamburg firestorm

  3. Efficient algorithms for wildland fire simulation

    Science.gov (United States)

    Kondratenko, Volodymyr Y.

    In this dissertation, we develop the multiple-source shortest path algorithms and examine their application importance in real world problems, such as wildfire modeling. The theoretical basis and its implementation in the Weather Research Forecasting (WRF) model coupled with the fire spread code SFIRE (WRF-SFIRE model) are described. We present a data assimilation method that gives the fire spread model the ability to start the fire simulation from an observed fire perimeter instead of an ignition point. While the model is running, the fire state in the model changes in accordance with the new arriving data by data assimilation. As the fire state changes, the atmospheric state (which is strongly effected by heat flux) does not stay consistent with the fire state. The main difficulty of this methodology occurs in coupled fire-atmosphere models, because once the fire state is modified to match a given starting perimeter, the atmospheric circulation is no longer in sync with it. One of the possible solutions to this problem is a formation of the artificial time of ignition history from an earlier fire state, which is later used to replay the fire progression to the new perimeter with the proper heat fluxes fed into the atmosphere, so that the fire induced circulation is established. In this work, we develop efficient algorithms that start from the fire arrival times given at the set of points (called a perimeter) and create the artificial fire time of ignition and fire spread rate history. Different algorithms were developed in order to suit possible demands of the user, such as implementation in parallel programming, minimization of the required amount of iterations and memory use, and use of the rate of spread as a time dependent variable. For the algorithms that deal with the homogeneous rate of spread, it was proven that the values of fire arrival times they produce are optimal. It was also shown that starting from arbitrary initial state the algorithms have

  4. Risk assessment of main control board fire using fire dynamics simulator

    International Nuclear Information System (INIS)

    Highlights: • A decision tree for evaluating the risk of a main control board (MCB) fire was proposed to systematically determine the MCB fire scenarios. • Fire simulations using fire dynamics simulator (FDS) were performed to estimate the time to MCR abandonment. • Non-propagating and propagating fire scenarios were considered for fire simulations. • The current study indicates that the quantification of the MCB fire risk should address the propagating fire and non-propagating fire scenarios if the MCB has no internal barriers between the panels. - Abstract: This paper presents the process and results of a risk assessment for a main control board (MCB) fire using fire dynamics simulator (FDS). A decision tree for evaluating the risk of a MCB fire was proposed to systematically determine the MCB fire scenarios, and fire simulations using FDS were performed to estimate the time to MCR abandonment. As a reference NPP for this study, Hanul unit 3 in Korea was selected and its core damage frequency (CDF) owing to the MCB fire was quantified. Two types of fire scenarios were considered for fire simulations: non-propagating fire scenarios occurring within a single MCB panel and propagating fire scenarios spreading from one control panel to the adjacent panels. Further, the fire scenarios were classified into fires with and without a heating, ventilation, and air conditioning system (HVACS). The fire simulation results showed that the major factor causing the MCR evacuation was the optical density irrelevant to the availability of the HVACS. The risk assessment results showed that the abandonment fire scenario risk was less than the non-abandonment fire scenario risk and the propagating fire scenario risk was greater than the non-propagating fire scenario risk

  5. Risk assessment of main control board fire using fire dynamics simulator

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dae Il, E-mail: dikang@kaeri.re.kr [KAERI, 1045 Daedeokdaero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Kim, Kilyoo; Jang, Seung-Cheol [KAERI, 1045 Daedeokdaero, Yuseong-Gu, Daejeon 305-353 (Korea, Republic of); Yoo, Seong Yeon [Chungnam National University, 79, Daehagro, Yuseong-Gu, Daejeon (Korea, Republic of)

    2015-08-15

    Highlights: • A decision tree for evaluating the risk of a main control board (MCB) fire was proposed to systematically determine the MCB fire scenarios. • Fire simulations using fire dynamics simulator (FDS) were performed to estimate the time to MCR abandonment. • Non-propagating and propagating fire scenarios were considered for fire simulations. • The current study indicates that the quantification of the MCB fire risk should address the propagating fire and non-propagating fire scenarios if the MCB has no internal barriers between the panels. - Abstract: This paper presents the process and results of a risk assessment for a main control board (MCB) fire using fire dynamics simulator (FDS). A decision tree for evaluating the risk of a MCB fire was proposed to systematically determine the MCB fire scenarios, and fire simulations using FDS were performed to estimate the time to MCR abandonment. As a reference NPP for this study, Hanul unit 3 in Korea was selected and its core damage frequency (CDF) owing to the MCB fire was quantified. Two types of fire scenarios were considered for fire simulations: non-propagating fire scenarios occurring within a single MCB panel and propagating fire scenarios spreading from one control panel to the adjacent panels. Further, the fire scenarios were classified into fires with and without a heating, ventilation, and air conditioning system (HVACS). The fire simulation results showed that the major factor causing the MCR evacuation was the optical density irrelevant to the availability of the HVACS. The risk assessment results showed that the abandonment fire scenario risk was less than the non-abandonment fire scenario risk and the propagating fire scenario risk was greater than the non-propagating fire scenario risk.

  6. Simulation of people's evacuation in tunnel fire

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The simulation model Tunev(tunnel evacuation) was developed for people's evacuation in tunnel fire. It contains simple database of the people's behavioral reaction and structure characteristic parameters of tunnel fireproofing. The model can be used to calculate the total evacuation time in various scenes when fire occurs in the different locations of the tunnel. Combined with fire simulation soft ware CFD- POENICS3.5, Tunev model can be used to calculate the fire danger coming time; by comparing with these two kinds of time, it can be used to assess the safety of the evacuation, and the evacuation process also have a dynamic demo. The simulation results show that the Tunev model can be used to predict the reliability of safe evacuation for people in tunnel fire and provide references for people's safe escape scheme. Some relevant concepts of the model were described and an evacuation simulation of a typical tunnel case, i.e. Xuefeng Mountain Tunnel was performed by using this model. And the model's validation and actual application were also described.

  7. Experimental ship fire measurements with simulated radioactive cargo

    International Nuclear Information System (INIS)

    Results from a series of eight test fires ranging in size from 2.2 to 18.8 MW conducted aboard the Coast Guard fire test ship Mayo Lykes at Mobile, Alabama are presented and discussed. Tests aboard the break bulk type cargo ship consisted of heptane spray fires simulating engine room and galley fires, wood crib fires simulating cargo hold fires, and pool fires staged for comparison to land based regulatory fire results. Primary instrumentation for the tests consisted of two pipe calorimeters that simulated a typical package shape for radioactive materials packages

  8. The French fire protection concept. Vulnerability analysis

    International Nuclear Information System (INIS)

    The French fire protection concept is based on a principle of three levels of defence in depth: fire prevention, fire containing and fire controlling. Fire prevention is based on arrangements which prevent the fire from starting or which make difficult for the fire to start. Fire containing is based on design measures so that the fire will have no impact on the safety of the installation. For fire controlling, equipment nad personnel are on duty in order to detect, to fight and to gain control over the fire as early as possible. The French fire protection concept gives priority to fire containing based on passive structural measures. All buildings containing safety equipment are divided into fire compartments (or fire areas) and fire cells (or fire zones). Basically, a compartment houses safety equipment belonging to one division (or train) so that the other division is always available to reach the plant safe shut down or to mitigate an accident. Because there is a large number of fire compartments and fire cells, deviations from the general principle can be observed. To this reason the RCC-I (Design and Construction Rules applicable for fire protection) requires to implement an assessment of the principle of division. This assessment is called vulnerability analysis. The vulnerability analysis is usually performed at the end of the project, before erection. It is also possible to perform a vulnerability analysis in an operating nuclear power plant in the scope of a fire safety upgrading programme. In the vulnerability analysis, the functional failure of all the equipment (except for those protected by a qualified fire barrier, designed or able to withstand the fire consequences) within the fire compartment or cell, where the fire breaks out, is postulated. The potential consequences for the plant safety are analysed

  9. Simulating statistics of lightning-induced and man made fires

    Science.gov (United States)

    Krenn, R.; Hergarten, S.

    2009-04-01

    The frequency-area distributions of forest fires show power-law behavior with scaling exponents α in a quite narrow range, relating wildfire research to the theoretical framework of self-organized criticality. Examples of self-organized critical behavior can be found in computer simulations of simple cellular automata. The established self-organized critical Drossel-Schwabl forest fire model (DS-FFM) is one of the most widespread models in this context. Despite its qualitative agreement with event-size statistics from nature, its applicability is still questioned. Apart from general concerns that the DS-FFM apparently oversimplifies the complex nature of forest dynamics, it significantly overestimates the frequency of large fires. We present a straightforward modification of the model rules that increases the scaling exponent α by approximately 1•3 and brings the simulated event-size statistics close to those observed in nature. In addition, combined simulations of both the original and the modified model predict a dependence of the overall distribution on the ratio of lightning induced and man made fires as well as a difference between their respective event-size statistics. The increase of the scaling exponent with decreasing lightning probability as well as the splitting of the partial distributions are confirmed by the analysis of the Canadian Large Fire Database. As a consequence, lightning induced and man made forest fires cannot be treated separately in wildfire modeling, hazard assessment and forest management.

  10. Methods of quantitative fire hazard analysis

    International Nuclear Information System (INIS)

    Simplified fire hazard analysis methods have been developed as part of the FIVE risk-based fire induced vulnerability evaluation methodology for nuclear power plants. These fire hazard analyses are intended to permit plant fire protection personnel to conservatively evaluate the potential for credible exposure fires to cause critical damage to essential safe-shutdown equipment and thereby screen from further analysis spaces where a significant fire hazard clearly does not exist. This document addresses the technical bases for the fire hazard analysis methods. A separate user's guide addresses the implementation of the fire screening methodology, which has been implemented with three worksheets and a number of look-up tables. The worksheets address different locations of targets relative to exposure fire sources. The look-up tables address fire-induced conditions in enclosures in terms of three stages: a fire plume/ceiling jet period, an unventilated enclosure smoke filling period and a ventilated quasi-steady period

  11. Computer Simulation of Fire Dynamics in Industrial Hall

    International Nuclear Information System (INIS)

    In this paper, computer simulation of smoke spread dynamics in industrial hall is investigated. A set of simulations of fire in three industrial halls with the same geometry varying in the height of ceiling is realized using the FDS fire simulator, version 6. The obtained simulation results are described focusing on the impact of the ceiling height and fire barriers on the fire course and smoke spread dynamics

  12. Simulation of fires based on flow calculation

    International Nuclear Information System (INIS)

    The fire simulation based on flow calculation is described in the publication, and the calculated result is compared with the results obtained from fire tests. The tests have been made in Germany in a nuclear power plant removed from service. The simulation describes the flow field of the entire building, the main features of the construction effecting on it and the edge conditions. The fire is described as a given source, the value of which varies as a function of time. Heat transfer into the constructions is described using a separate heat transfer program. The result obtained from calculation describes the flow and temperature fields formed in a fire generally correctly. Due to the used sparse calculation network the results contain locally large deviations. The discrete-transfer radiation calculation method used for calculation of burning and heat transfer, and testing of it are described in the appendix. The method describes the heat radiation propagating diagonally to the calculation network better than the six-flux method used before

  13. Two typical phenomena from the numerical simulation of fire and smoke transport in a gymnasium fire

    Institute of Scientific and Technical Information of China (English)

    CHEN Jianguo; CHEN Haixin; FU Song

    2006-01-01

    Navier-Stokes equations are solved to simulate a gymnasium fire. The equations are simplified by weakly compressible low Mach number assumption. Turbulence effect is simulated using Smagorinsky large eddy simulation (LES) model. The mixture fraction combustion model is adopted to simulate the burning process. With the analysis of computed velocity and temperature field, two important phenomena, named door effect and smoke plug-holing, are found to be responsible for the deterioration of smoke exhaust efficiency when natural ventilation or forced ventilation is present. Some explanations are made to elucidate these effects' mechanism. An improved design of smoke ventilation system is suggested.

  14. A CFD Validation of Fire Dynamics Simulator for ‎Corner Fire

    OpenAIRE

    Pavan K Sharma; Gera‎ R.K. Singh

    2010-01-01

    A computational study has been carried out for predicting the behaviour of a corner fire ‎source for a ‎reported experiment using a field model based code Fire Dynamics Simulator ‎‎(FDS). Time ‎dependent temperature is predicted along with the resulting changes in the ‎plume structure. The flux ‎falling on the wall was also observed. The analysis has been ‎carried out with the correct value of the ‎grid size based on earlier experiences and also by ‎performing a grid sensitivity study. The pr...

  15. Data Assimilation of Satellite Fire Detection in Coupled Atmosphere-Fire Simulation by WRF-SFIRE

    CERN Document Server

    Mandel, Jan; Vejmelka, Martin; Beezley, Jonathan D

    2014-01-01

    Currently available satellite active fire detection products from the VIIRS and MODIS instruments on polar-orbiting satellites produce detection squares in arbitrary locations. There is no global fire/no fire map, no detection under cloud cover, false negatives are common, and the detection squares are much coarser than the resolution of a fire behavior model. Consequently, current active fire satellite detection products should be used to improve fire modeling in a statistical sense only, rather than as a direct input. We describe a new data assimilation method for active fire detection, based on a modification of the fire arrival time to simultaneously minimize the difference from the forecast fire arrival time and maximize the likelihood of the fire detection data. This method is inspired by contour detection methods used in computer vision, and it can be cast as a Bayesian inverse problem technique, or a generalized Tikhonov regularization. After the new fire arrival time on the whole simulation domain is...

  16. A CFD Validation of Fire Dynamics Simulator for ‎Corner Fire

    Directory of Open Access Journals (Sweden)

    Pavan K. Sharma

    2010-12-01

    Full Text Available A computational study has been carried out for predicting the behaviour of a corner fire ‎source for a ‎reported experiment using a field model based code Fire Dynamics Simulator ‎‎(FDS. Time ‎dependent temperature is predicted along with the resulting changes in the ‎plume structure. The flux ‎falling on the wall was also observed. The analysis has been ‎carried out with the correct value of the ‎grid size based on earlier experiences and also by ‎performing a grid sensitivity study. The predicted ‎temperatures of the two scenarios at two ‎points by the current analysis are in very good agreement ‎with the earlier reported ‎experimental data and numerical prediction. The studies have extended the ‎utility of field ‎model based tools to model the particular separate effect phenomenon like corner for ‎one ‎such situation and validate against experimental data. The present study have several ‎‎applications in such as room fires, hydrogen transport in nuclear reactor containment, ‎natural ‎convection in building flows etc. The present approach uses the advanced Large ‎Eddy Simulation ‎‎(LES based CFD turbulence model. The paper presents brief description ‎of the code FDS, details ‎of the computational model along with the discussions on the ‎results obtained under these studies. ‎The validated CFD based procedure has been used for ‎solving various problems enclosure fire, ‎ventilated fire and open fire from nuclear industry ‎which are however not included in the present ‎paper. ‎

  17. Brunswick steam electric plant probabilistic fire analysis

    International Nuclear Information System (INIS)

    A probabilistic safety analysis of fires was performed for the Brunswick Plant as part of the overall BSEP probabilistic risk assessment (PRA) program. The prime feature of the model is that plant-specific historical data were used to calculate the frequency of fire ignition for each zone. Fire growth and suppression parameters leading to fires of sufficient size to cause damage to redundant trains of equipment were also developed. The Brunswick Plant fire model was developed in such a way as to easily identify dominant fire zones, ignition sources, combustible sources, cable damage locations, and random equipment failures. After NRC reviews, it is expected that this probabilistic fire analysis model will continue to be used as a basis for fire risk reduction activities, for continued improvements to the fire protection program and procedures, and possibly for supporting licensing positions. 9 refs

  18. Improvement and upgrade of mine fire simulation program MFIRE

    Institute of Scientific and Technical Information of China (English)

    ZHOU Li-hong; LUO Yi

    2011-01-01

    MFIRE,an underground mine fire simulation program developed in 1980's,is a tool that can be used to simulate the impacts of a mine fire event to a mine ventilation network.However,the lack of the abilities to simulate some of the important mine fire phenomena realistically hindered its wide applications.This research carried out to improve and upgrade the MFIRE 2.20 program to MFIRE 2.30.The new additions of MFIRE 2.30 including a time dependent fire model,smoke rollback prediction,the incorporation of a moving fire source,and a rewriting of MFIRE in Microsoft Visual C++ were interpreted.

  19. A case study on fractal simulation of forest fire spread

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper relates to the semi-empirical model based on fire field energy balance and the physical model based on land temperature,aiming to provide a practical way of describing fire spread.Fire spread is determined by the characteristics of combustible materials and the agency of meteorological factors and terrains.Combustible materials,such as surface area,have no featured scale,yet the process of forest fire spread contains the self-replicating feature,both of which contribute to the self-similarity of fire spread.Consequently,fire behavior can be described by fractal geometry.In this research,we select Wuchagou forest in Da Hinggan Mountains as the experimental site where a forest fire took place three years ago.The forest fire was detected on low-resolution NOAA-AVHRR images,and fire spread was simulated on high-resolution TM images as another attempt to merge information.Based on remote sensing and GIS,we adopted the method of limited spreading lumping (DLA) to describe growing phenomenon to simulate the dynamic process of fire spread and adjusting shape of the result of fire simulation by the scale rule.As a result,the simulated fire and the actual fire manifest the self-similarity in their spreading shapes as well as the quantitative similarity in their areas.

  20. Human reliability analysis under fire condition

    International Nuclear Information System (INIS)

    It is identified in the fire probabilistic safety assessment (PSA) of nuclear power plants that human action has important effect on the risk of plant under fire condition. So it's necessary to assess human error probability under fire condition by the systemic methodology. The HCR/ORE and CBDTM models and specific considerations under fire condition were described in this paper. The combination of HCR/ORE, CBDTM and THERP was applied to human reliability analysis (HRA) under fire condition with an example given for demonstration. The basement of setting up the more practical fire PSA models for engineering is established. (authors)

  1. Numerical simulation of a biomass fired grate boiler

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2006-01-01

    Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion furnace of a biomass-fired grate boiler provides crucial insight into the boiler's performance. Quite a few factors play important roles in a general CFD analysis, such as grid, models, discretization scheme and so on....... For a grate boiler, the modeling the interaction of the fuel bed and the gas phase above the bed is also essential. Much effort can be found in literature on developing bed models whose results are introduced into CFD simulations of freeboard as inlet conditions. This paper presents a CFD analysis of...... the largest biomass-fired grate boiler in Denmark. The focus of this paper is to study how significantly an accurate bed model can affect overall CFD results, i.e., how necessarily it is to develop an accurate bed model in terms of the reliability of CFD results. The ultimate purpose of the study is...

  2. The application of virtual reality to the simulation of mine fires and explosions

    OpenAIRE

    Walsha, Timothy

    1999-01-01

    Despite significant improvements in mine safety, underground mine fires and explosions are responsible for a significant number of deaths world-wide each year. The training of personnel in safety procedures has had a significant impact on reducing the frequency of injuries and fatalities. This thesis presents an innovative virtual reality simulation, 'Fire-VR', designed to enhance the visualisation of a mine ventilation system. Fire-VR incorporates existing ventilation network analysis pr...

  3. Exploratory Studies Facility Subsurface Fire Hazards Analysis

    International Nuclear Information System (INIS)

    The primary objective of this Fire Hazard Analysis (FHA) is to confirm the requirements for a comprehensive fire and related hazards protection program for the Exploratory Studies Facility (ESF) are sufficient to minimize the potential for: (1) The occurrence of a fire or related event. (2) A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public or the environment. (3) Vital US. Department of Energy (DOE) programs suffering unacceptable interruptions as a result of fire and related hazards. (4) Property losses from a fire and related events exceeding limits established by DOE. (5) Critical process controls and safety class systems being damaged as a result of a fire and related events

  4. Fire hazard analysis for fusion energy experiments

    International Nuclear Information System (INIS)

    The 2XIIB mirror fusion facility at Lawrence Livermore Laboratory (LLL) was used to evaluate the fire safety of state-of-the-art fusion energy experiments. The primary objective of this evaluation was to ensure the parallel development of fire safety and fusion energy technology. Through fault-tree analysis, we obtained a detailed engineering description of the 2XIIB fire protection system. This information helped us establish an optimum level of fire protection for experimental fusion energy facilities as well as evaluate the level of protection provided by various systems. Concurrently, we analyzed the fire hazard inherent to the facility using techniques that relate the probability of ignition to the flame spread and heat-release potential of construction materials, electrical and thermal insulations, and dielectric fluids. A comparison of the results of both analyses revealed that the existing fire protection system should be modified to accommodate the range of fire hazards inherent to the 2XIIB facility

  5. Exploratory Studies Facility Subsurface Fire Hazards Analysis

    International Nuclear Information System (INIS)

    The primary objective of this Fire Hazard Analysis (FHA) is to confirm the requirements for a comprehensive fire and related hazards protection program for the Exploratory Studies Facility (ESF) are sufficient to minimize the potential for: The occurrence of a fire or related event; A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public or the environment; Vital U.S. Department of Energy (DOE) programs suffering unacceptable interruptions as a result of fire and related hazards; Property losses from a fire and related events exceeding limits established by DOE; and Critical process controls and safety class systems being damaged as a result of a fire and related events

  6. Application of Computer Integration Technology for Fire Safety Analysis

    Institute of Scientific and Technical Information of China (English)

    SHI Jianyong; LI Yinqing; CHEN Huchuan

    2008-01-01

    With the development of information technology, the fire safety assessment of whole structure or region based on the computer simulation has become a hot topic. However, traditionally, the concemed studies are performed separately for different objectives and difficult to perform an overall evaluation. A new multi-dimensional integration model and methodology for fire safety assessment were presented and two newly developed integrated systems were introduced to demonstrate the function of integration simulation technology in this paper. The first one is the analysis on the fire-resistant behaviors of whole structure under real fire loads. The second one is the study on fire evaluation and emergency rescue of campus based on geography information technology (GIS). Some practical examples are presented to illuminate the advan-tages of computer integration technology on fire safety assessment and emphasize some problems in the simulation. The results show that the multi-dimensional integration model offers a new way and platform for the integrating fire safety assessment of whole structure or region, and the integrated software developed is the useful engineering tools for cost-saving and safe design.

  7. Fire hazard analysis for the fuel supply shutdown storage buildings

    International Nuclear Information System (INIS)

    The purpose of a fire hazards analysis (FHA) is to comprehensively assess the risk from fire and other perils within individual fire areas in a DOE facility in relation to proposed fire protection so as to ascertain whether the objectives of DOE 5480.7A, Fire Protection, are met. This Fire Hazards Analysis was prepared as required by HNF-PRO-350, Fire Hazards Analysis Requirements, (Reference 7) for a portion of the 300 Area N Reactor Fuel Fabrication and Storage Facility

  8. The use of CAFE-3D for the simulation of tunnel fires

    International Nuclear Information System (INIS)

    Fires after accidents inside tunnels, such as the July 2001 Howard Street Tunnel fire in Baltimore, Maryland, USA, have raised stakeholder questions concerning the survivability of a spent nuclear fuel (SNF) transport cask when exposed to similar thermal environments. The analysis of tunnel fires is a computational challenge because of the need for very large computational domains in order to fully simulate such a problem. In this paper, the analyses of two different tunnel fire scenarios are described and the performance of typical SNF casks when exposed to these tunnel fire environments is discussed. The CAFE-3D fire code is used to model a series of fires inside tunnels, and the thermal performance of a SNF transportation cask within such fire environments is estimated with the use of the MSC PATRAN-P/Thermal finite element analysis code. The methodology used to simulate this type of fire scenario as well as a description of the manner in which the CAFE code couples the computational fluid dynamics and the finite element analysis techniques are also presented

  9. Numerical simulation methods of fires in nuclear power plants

    International Nuclear Information System (INIS)

    Fire is a significant hazard to the safety of nuclear power plants (NPP). Fire may be serious accident as such, but even small fire at a critical point in a NPP may cause an accident much more serious than fire itself. According to risk assessments a fire may be an initial cause or a contributing factor in a large part of reactor accidents. At the Fire Technology and the the Nuclear Engineering Laboratory of the Technical Research Centre of Finland (VTT) fire safety research for NPPs has been carried out in a large extent since 1985. During years 1988-92 a project Advanced Numerical Modelling in Nuclear Power Plants (PALOME) was carried out. In the project the level of numerical modelling for fire research in Finland was improved by acquiring, preparing for use and developing numerical fire simulation programs. Large scale test data of the German experimental program (PHDR Sicherheitsprogramm in Kernforschungscentral Karlsruhe) has been as reference. The large scale tests were simulated by numerical codes and results were compared to calculations carried out by others. Scientific interaction with outstanding foreign laboratories and scientists has been an important part of the project. This report describes the work of PALOME-project carried out at the Fire Technology Laboratory only. A report on the work at the Nuclear Engineering Laboratory will be published separatively. (au)

  10. Turbulence and fire-spotting effects into wild-land fire simulators

    CERN Document Server

    Kaur, Inderpreet; Bosseur, Frédéric; Filippi, Jean-Baptiste; Pagnini, Gianni

    2016-01-01

    This paper presents a mathematical approach to model the effects and the role of phenomena with random nature such as turbulence and fire-spotting into the existing wildfire simulators. The formulation proposes that the propagation of the fire-front is the sum of a drifting component (obtained from an existing wildfire simulator without turbulence and fire-spotting) and a random fluctuating component. The modelling of the random effects is embodied in a probability density function accounting for the fluctuations around the fire perimeter given by the drifting component. In past, this formulation has been applied to include these random effects into a wildfire simulator based on an Eulerian moving interface method, namely the Level Set Method (LSM), but in this paper the same formulation is adapted for a wildfire simulator based on a Lagrangian front tracking technique, namely the Discrete Event System Specification (DEVS). Simple idealised numerical experiments are used to compare the performances of the LSM...

  11. Simulation of smoke flow and longitudinal ventilation in tunnel fire

    Institute of Scientific and Technical Information of China (English)

    YANG Gao-shang; AN Yong-lin; PENG Li-min; ZHANG Jin-hua

    2006-01-01

    Understanding the characteristics of smoke flow in tunnel fire is very important for tunnel safety. The characteristics of tunnel fire were analyzed. The smoke development in different situations of an engineering example was simulated using commercial CFD software PHOENICS 3.5 by field modeling method. The spreading rules and characteristics of concentration field and temperature field of smoke flow with different longitudinal ventilation speeds were studied, which may provide the theoretical background for evacuation design in tunnel fire. The effective measures of fire rescue and crowd evacuation were also described.

  12. Repository Subsurface Preliminary Fire Hazard Analysis

    International Nuclear Information System (INIS)

    This fire hazard analysis identifies preliminary design and operations features, fire, and explosion hazards, and provides a reasonable basis to establish the design requirements of fire protection systems during development and emplacement phases of the subsurface repository. This document follows the Technical Work Plan (TWP) (CRWMS M and O 2001c) which was prepared in accordance with AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''; Attachment 4 of AP-ESH-008, ''Hazards Analysis System''; and AP-3.11Q, ''Technical Reports''. The objective of this report is to establish the requirements that provide for facility nuclear safety and a proper level of personnel safety and property protection from the effects of fire and the adverse effects of fire-extinguishing agents

  13. Analysis of large urban fires

    International Nuclear Information System (INIS)

    Fires in urban areas caused by a nuclear burst are analyzed as a first step towards determining their smoke-generation chacteristics, which may have grave implications for global-scale climatic consequences. A chain of events and their component processes which would follow a nuclear attack are described. A numerical code is currently being developed to calculate ultimately the smoke production rate for a given attack scenario. Available models for most of the processes are incorporated into the code. Sample calculations of urban fire-development history performed in the code for an idealized uniform city are presented. Preliminary results indicate the importance of the wind, thermal radiation transmission, fuel distributions, and ignition thresholds on the urban fire spread characteristics. Future plans are to improve the existing models and develop new ones to characterize smoke production from large urban fires. 21 references, 18 figures

  14. Combined fire confinement and fire influence framework for fire hazard analysis/design safety margin evaluation/audit for nuclear power plant and reprocessing facilities

    International Nuclear Information System (INIS)

    The Fire Hazard Analysis (FHA) is mandatory requirement to ascertain the adequacy of principal of fire safety and fire protection measures provided in the plant for safe operational/emergency states of the plant and ensure nuclear safety objective using defense-in-depth philosophy so that a fire that starts in spite of prevention programme will not prevent essential plant safety functions from being performed. The term ‘hazard analysis’ does not involve any probabilistic estimation with regard to fire in current approach. The results of Fire Probabilistic Safety Assessment (FPSA) contributed to design modifications in plant to enhance the safety and thereby reduce its contribution to Core Damage Frequency but the FHA procedure is kept independent from any probabilistic input. The FHA is carried out using the engineering judgment, a new combined fire containment approach and fire influence approach with deterministic modelling framework. Qualitative assessment based on the acts, rules, standards and codes followed in design are also suggested wherever applicable. The fire hazard analysis has been completed for 5 plant of Fast Reactor Fuel Cycle facility (FRFCF) IPHWRs. The FHA has utilised also few CFD based fire influence simulation wherever required. (author)

  15. Fire-accident analysis code (FIRAC) verification

    International Nuclear Information System (INIS)

    The FIRAC computer code predicts fire-induced transients in nuclear fuel cycle facility ventilation systems. FIRAC calculates simultaneously the gas-dynamic, material transport, and heat transport transients that occur in any arbitrarily connected network system subjected to a fire. The network system may include ventilation components such as filters, dampers, ducts, and blowers. These components are connected to rooms and corridors to complete the network for moving air through the facility. An experimental ventilation system has been constructed to verify FIRAC and other accident analysis codes. The design emphasizes network system characteristics and includes multiple chambers, ducts, blowers, dampers, and filters. A larger industrial heater and a commercial dust feeder are used to inject thermal energy and aerosol mass. The facility is instrumented to measure volumetric flow rate, temperature, pressure, and aerosol concentration throughout the system. Aerosol release rates and mass accumulation on filters also are measured. We have performed a series of experiments in which a known rate of thermal energy is injected into the system. We then simulated this experiment with the FIRAC code. This paper compares and discusses the gas-dynamic and heat transport data obtained from the ventilation system experiments with those predicted by the FIRAC code. The numerically predicted data generally are within 10% of the experimental data

  16. Validation process of the ISIS CFD software for fire simulation

    International Nuclear Information System (INIS)

    Fire codes are more and more used for safety analysis of nuclear power plants. In several OECD member countries, the accuracy of the calculated simulation with CFD code has to be demonstrated; this is the aim of the Verification and Validation process (V and V). In this context the French 'Institut de Radioprotection et de Surete Nucleaire' (IRSN) develops a computational software, named ISIS, dedicated to the simulation of buoyant fire in compartment mechanically ventilated. ISIS is based on the scientific computing development platform PELICANS and benefits of the practicalities for implementing methods. The code ISIS is a freeware, available at https://gforge.irsn.fr/gf/project/isis. The physical modelling used in ISIS is classic for industrial application in large compartments. The turbulence approach is based on the Reynolds-Averaged-Navier-Stokes equations, supplemented by a two-equation closure and the eddy viscosity model. The turbulent production term is adapted to cope with buoyancy effects. Combustion modelling relies on a single reaction equation. The classical eddy dissipation approach is used for the mean chemical reaction rate which means that it is controlled solely by the turbulent mixture. The Finite Volume method is employed to treat radiation exchanges. Both incompressible and low Mach number flows are dealt with. The originality of the ISIS code is its capacity to take into account the effect of ventilation on the pressure. The thermodynamic pressure and the mass flow rate for ventilation vents are related by the mass balances in the compartment and in the ventilation branch where an aeraulic resistance is taken into account. For numerical solution, a fractional step algorithm has been developed. The spatial discretization combines mixed finite element for the Navier-Stokes equation and finite volumes scheme for transport (advection-diffusion-reaction) equation in order to ensure the velocity stability and the conservation in physical range of

  17. Effect Analysis of Fans Activating Time on Smoke Control Mode for Road Tunnel Fire

    OpenAIRE

    Xin Han; Beihua Cong; Xinna Li; Lili Han

    2013-01-01

    With the development of economy, more and more road tunnels have been built. Due to the relatively isolated environment of the tunnel, fire protection is the most important factor for the safe management of tunnel operation. During the fire process, many people are killed by the fire smoke. As for preventive measures of road tunnel fire, smoke exhaust system is the most effective way to control the spread of fire smoke. Based on full size tunnel fire test and simulation analysis, this study c...

  18. A case study on fractal simulation of forest fire spread

    Institute of Scientific and Technical Information of China (English)

    朱启疆; 戎太宗; 孙睿

    2000-01-01

    This paper relates to the semi-empirical model based on fire field energy balance and the physical model based on land temperature, aiming to provide a practical way of describing fire spread. Fire spread is determined by the characteristics of combustible materials and the agency of meteorological factors and terrains. Combustible materials, such as surface area, have no featured scale, yet the process of forest fire spread contains the self-replicating feature, both of which contribute to the self-similarity of fire spread. Consequently, fire behavior can be described by fractal geometry. In this research, we select Wuchagou forest in Da Hinggan Mountains as the experimental site where a forest fire took place three years ago. The forest fire was detected on low-resolution NOAA-AVHRR images, and fire spread was simulated on high-resolution TM images as another attempt to merge information. Based on remote sensing and GIS, we adopted the method of limited spreading lumping (DLA) to describe growing phe

  19. Dynamic model of Fire Growth in Abernethy Estate and Glen Tanar using FARSITE simulator

    OpenAIRE

    Grabowiecka, Magdalena

    2008-01-01

    Most of the vegetation fires in Great Britain are of an anthropogenic nature. The possibility of a wildfire occurrence depends on the combination of human behaviour, the type and condition of the vegetation and the weather conditions. By using FARSITE – Fire Area Simulator it is easy to develop a two-dimensional output such as Fire Growth model on personal computer. The simulator incorporates existing fire behaviour models of surface fire spread, crown fire, fire acceleration, fuel moisture a...

  20. Simulation of a compartment fire using a zone model

    Institute of Scientific and Technical Information of China (English)

    YANG Lizhong; GUO Zaifu; JI Jingwei; FAN Weicheng

    2005-01-01

    This paper presents the zone modeling analysis of a single compartment flashover fire. Two criteria are applied in the model to judge the onset of ignition for different combustibles. By calculating the total received energy through radiation or the surface temperature of the combustible, the fire growth can be quantitatively determined. The improved zone fire model shows the influence of different combustibles upon the fire growth. This model is better than the traditional zone model because the common criteria of flashover, i.e. an upper layer temperature of 600℃ and the heat radiation intensity received by the floor of 20 kW/m2, have not been applied in it.

  1. Fire Hazard Analysis for the Cold Vacuum Drying (CVD) Facility

    International Nuclear Information System (INIS)

    This Fire Hazard Analysis assesses the risk from fire within individual fire areas in the Cold Vacuum Drying Facility at the Hanford Site in relation to existing or proposed fire protection features to ascertain whether the objectives of DOE Order 5480.7A Fire Protection are met

  2. Fire Hazard Analysis for the Cold Vacuum Drying (CVD) Facility

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON, B.H.

    1999-08-19

    This Fire Hazard Analysis assesses the risk from fire within individual fire areas in the Cold Vacuum Drying Facility at the Hanford Site in relation to existing or proposed fire protection features to ascertain whether the objectives of DOE Order 5480.7A Fire Protection are met.

  3. Probabilistic analysis of fires in nuclear plants

    International Nuclear Information System (INIS)

    The aim of this paper is to describe a multilevel (i.e., staged) probabilistic analysis of fire risks in nuclear plants (as part of a general PRA) which maximizes the benefits of the FRA (fire risk assessment) in a cost effective way. The approach uses several stages of screening, physical modeling of clearly dominant risk contributors, searches for direct (e.g., equipment dependences) and secondary (e.g., fire induced internal flooding) interactions, and relies on lessons learned and available data from and surrogate FRAs. The general methodology is outlined. 6 figs., 10 tabs

  4. Quantitative analysis of forest fire extinction efficiency

    Directory of Open Access Journals (Sweden)

    Miguel E. Castillo-Soto

    2015-08-01

    Full Text Available Aim of study: Evaluate the economic extinction efficiency of forest fires, based on the study of fire combat undertaken by aerial and terrestrial means. Area of study, materials and methods: Approximately 112,000 hectares in Chile. Records of 5,876 forest fires that occurred between 1998 and 2009 were analyzed. The area further provides a validation sector for results, by incorporating databases for the years 2010 and 2012. The criteria used for measuring extinction efficiency were economic value of forestry resources, Contraction Factor analysis and definition of the extinction costs function. Main results: It is possible to establish a relationship between burnt area, extinction costs and economic losses. The method proposed may be used and adapted to other fire situations, requiring unit costs for aerial and terrestrial operations, economic value of the property to be protected and speed attributes of fire spread in free advance. Research highlights: The determination of extinction efficiency in containment works of forest fires and potential projection of losses, different types of plant fuel and local conditions favoring the spread of fire broaden the admissible ranges of a, φ and Ce considerably.

  5. Fully coupled numerical simulation of fire in tunnels: From fire scenario to structural response

    Directory of Open Access Journals (Sweden)

    Pesavento F.

    2013-09-01

    Full Text Available In this paper we present an efficient tool for simulation of a fire scenario in a tunnel. The strategy adopted is based on a 3D-2D coupling technique between the fluid domain and the solid one. So, the thermally driven CFD part is solved in a three dimensional cavity i.e. the tunnel, and the concrete part is solved on 2D sections normal to the tunnel axis, at appropriate intervals. The heat flux and temperature values, which serve as coupling terms between the fluid and the structural problem, are interpolated between the sections. Between the solid and the fluid domain an interface layer is created for the calculation of the heat flux exchange based on a “wall law”. In the analysis of the concrete structures, concrete is treated as a multiphase porous material. Some examples of application of this fully coupled tool will be shown.

  6. FDS3 simulations of indoor hydrocarbon fires engulfing radioactive waste packages

    International Nuclear Information System (INIS)

    The thermal environment of a hypothetical large indoor hydrocarbon pool fire is more complex compared to outdoor fires and can be more severe for engulfed objects. In order to analyze potential thermal environments for interim storage of spent fuel casks or low-level radioactive waste packages engulfed in pool fires numerical simulations with the CFD fire code FDS3 were carried out for different storage configurations. In addition, data of indoor pool fire experiments were used to validate the model for this type of application. A series of pool fire experiments under different ventilation conditions and varied pool surface (1 m2 - 4 m2) inside a compartment of 3.6 m x 3.6 m x 5.7 m was conducted at iBMB (Institut fuer Baustoffe, Massivbau und Brandschutz) of Braunschweig University of Technology, Germany. The instrumentation included thermocouples, heatflux and pressure gauges, bi-directional flow probes and gas concentration measurements. A mock low-level waste drum equipped with outside and inside thermocouples was positioned as an additional heat sink near the fire source. Two of these experiments have recently been used for benchmarking a number of fire simulation codes within the International Collaborative Fire Model Project (ICFMP). FDS3 simulations by GRS of some of the above mentioned experiments will be presented showing the ability of the model to sufficiently well represent the fire environment in most cases. Further simulations were performed for hypothetical pool fire environments in interim storage facilities for German spent fuel transport and storage casks. The resulting temperature curves were then used for the thermomechanical analysis of the cask reaction performed by BAM (Bundesanstalt fuer Materialforschung und -pruefung, see corresponding conference paper by Wieser et al.). The FDS3 pool fire simulations show that the fire environment is strongly influenced by the ventilation conditions and cooling effects depending on the number and

  7. An Assessment of Fire Regime Changes in the Northern Rocky Mountain Region Using Simulated Historical Fire Maps and Remotely Sensed Current Fires

    Science.gov (United States)

    Zhao, F.; Zhu, Z.; Huang, C.

    2011-12-01

    Wildland fire is a primary ecosystem process that shapes the landscape of Western United States. Changes in fire regime can therefore have profound impact on ecosystem functions and services, including carbon cycling, habitat conditions, and biodiversity. This poster presents a study on current fire regime and changes in the Northern Rocky Mountain region assessed using contemporary and historical fire regimes. Contemporary fire records from 1984 to 2008 were obtained from the Monitoring Trends in Burn Severity (MTBS) project. Historical (pre-EuroAmerican settlement) fire regimes and fire regime condition class (FRCC), produced by the LANDFIRE project, were simulated using a Landscape Succession Model (LANDSUM). We extracted historical fire frequency (Mean Fire Interval) and fire severity (percentage of severe fire) data from LANDFIRE, and calculated current fire frequency and severity using MTBS data by following the FRCC definition, to evaluate changes in fire regimes in Northern Rocky Mountain area. Preliminary results reveal that the current fire regime in Northern Rocky Mountains may exhibit a general pattern of longer return intervals and more severe fires. Biophysical Setting (BpS) map units from LANDFIRE are used as study units to describe environmental gradients and will be used to further examine whether the observed fire regime changes are controlled by land cover or biophysical settings. The findings of this study will help reveal contemporary fire dynamics in this region and serve for future fire studies and other forest management applications.

  8. Calculations detailed progression of fire in NPP ALMARAZ through the code computational fire dynamics SIMULATOR; Calculos detallados de progresion de incendios en C.N. Alamaraz mediante el codigo coputacional Fire Dynamics Simulator

    Energy Technology Data Exchange (ETDEWEB)

    Villar Sanchez, T.

    2012-07-01

    (FDS) is an advanced computational model of calculation of simulation of fire that numerically solves the Navier-Stokes equations in each cell of the mesh in each interval of time, having capacity to calculate accurately all those parameters of fire to NUREG-1805 has a limited capacity. The objective of the analysis is to compare the results obtained with the FDS with those obtained from spreadsheets of NUREG-1805 and deal widespread and realistic study of the propagation of a fire in different areas of NPP Almaraz.

  9. Effect Analysis of Fans Activating Time on Smoke Control Mode for Road Tunnel Fire

    Directory of Open Access Journals (Sweden)

    Xin Han

    2013-04-01

    Full Text Available With the development of economy, more and more road tunnels have been built. Due to the relatively isolated environment of the tunnel, fire protection is the most important factor for the safe management of tunnel operation. During the fire process, many people are killed by the fire smoke. As for preventive measures of road tunnel fire, smoke exhaust system is the most effective way to control the spread of fire smoke. Based on full size tunnel fire test and simulation analysis, this study carries out effect analysis of fans activating time on smoke control mode for road tunnel fire. The corresponding results are useful to establish fire control strategy and personnel evacuation plan for tunnel management system.

  10. Vortical structures in pool fires: Observation, speculation, and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Tieszen, S.R.; Nicolette, V.F.; Gritzo, L.A.; Moya, J.L. [Sandia National Labs., Albuquerque, NM (United States); Holen, J.K. [SINTEF/NTH, Trondheim (Norway). Div. Thermodynamics; Murray, D. [Naval Air Warfare Center, China Lake, CA (United States)

    1996-11-01

    While all fires are complex and involve many phenomena, this report is limited to large, turbulent liquid-hydrocarbon pool fires. Large, liquid-hydrocarbon pool fires present a risk in petrochemical storage and processing facilities and transportation systems that contain large amounts of liquid hydrocarbons. This report describes observations, speculations, and numerical simulations of vortical structures in pool fires. Vortical structures are observed in fires with length scales ranging from those that bend millimeter-thick flame zones to those that entrain air many meters from the edge of the fire to its centerline. The authors propose that baroclinic vorticity generation is primarily responsible for production of rotational motion at small scale and that amalgamation is responsible for the production of large-scale rotational structures from the myriad of small-scale structures. Numerical simulations show that vortical structures having time-mean definitions can be resolved with a Reynolds-Average Navier-Stokes (RANS) approach. However, for vortical structures without time-mean definition, RANS is inappropriate, and another technique, such as Large Eddy Simulation (LES), should be employed. 39 refs., 52 figs., 3 tabs.

  11. Fire hazards analysis for solid waste burial grounds

    International Nuclear Information System (INIS)

    This document comprises the fire hazards analysis for the solid waste burial grounds, including TRU trenches, low-level burial grounds, radioactive mixed waste trenches, etc. It analyzes fire potential, and fire damage potential for these facilities. Fire scenarios may be utilized in future safety analysis work, or for increasing the understanding of where hazards may exist in the present operation

  12. Large eddy simulation based fire modeling applications for Indian nuclear power plant

    International Nuclear Information System (INIS)

    Full text of publication follows: The Nuclear Power Plants (NPPs) are always designed for the highest level of safety against postulated accidents which may be initiated due to internal or external causes. One of the external/internal causes, which may lead to accident in the reactor and its associated systems, is fire in certain vital areas of the plant. Conventionally, the fire containment approach and/or the fire confinement approach is used in designing the fire protection systems of NPPs. Indian NPPs (PHWRs) follow the combined approach to ensure plant safety and all newly designed plants are required to comply with the provisions of Atomic Energy Regulatory Board (AERB) fire safety Guide. In respect of older plants, the reassessment of adequacy of fire safety provisions in the light of current advances has becomes essential so as to decide upon the steps for retrofitting. Keeping this in mind the deterministic fire hazard analysis was carried out for the Madras Atomic Power Station (MAPS). As a part of this exercise, detailed fire consequences analysis was required to be carried out for various critical areas. The choice of CFD based code was considered appropriate for these studies. A dedicated fire hazard analysis code Fire Dynamics Simulator (FDS) from NIST was used to perform these case studies. The code has option to use advanced fire models based on Large Eddy Simulation (LES) technique/ Direct Numerical Simulation (DNS) to model the fire-generated conditions. The LES option has been extensively used in the present studies which were primarily aimed at estimating the damage time for important safety related cable. Present paper describes the salient features of the methodology and important results for one of the most critical areas i.e. cable bridge area of MAPS. The typical dimensions of the cable bridge area are (length x breadth x height) of 12 m x 6 m x 2.5 m with an opening on one side of the cable bridge area. With almost equal gap, six numbers

  13. The influence of sodium fires on LMFBRs safety analysis

    International Nuclear Information System (INIS)

    In a sodium cooled reactor, sodium fires are accidental conditions to be taken into account in safety analysis. For the various sodium categories, fire conditions, associated risks, safety analysis objectives and detailed corresponding issues are indicated, An experimental research program can be deduced from these considerations. This report covers the following: safety analysis methodology; primary sodium fires; secondary sodium fires; auxiliary sodium fires, and related experimental research programs

  14. Fire spread simulation of a full scale cable tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Huhtanen, R. [VTT Energy, Espoo (Finland)

    1999-11-01

    A fire simulation of a full scale tunnel was performed by using the commercial code EFFLUENT as the simulation platform. Estimation was made for fire spread on the stacked cable trays, possibility of fire spread to the cable trays on the opposite wall of the tunnel, detection time of smoke detectors in the smouldering phase and response of sprinkler heads in the flaming phase. According to the simulation, the rise of temperature in the smouldering phase is minimal, only of the order 1 deg C. The estimates of optical density of smoke show that normal smoke detectors should give an alarm within 2-4 minutes from the beginning of the smouldering phase, depending on the distance to the detector (in this case it was assumed that the thermal source connected to the smoke source was 50 W). The flow conditions at smoke detectors may be challenging, because the velocity magnitude is rather low at this phase. At 4 minutes the maximum velocity at the detectors is 0.12 m/s. During the flaming phase (beginning from 11 minutes) fire spreads on the stacked cable trays in an expected way, although the ignition criterion seems to perform poorly when ignition of new objects is considered. The Upper cable trays are forced to ignite by boundary condition definitions according to the experience found from ti full scale experiment and an earlier simulation. After 30 minutes the hot layer in the room becomes so hot that it speeds up the fire spread and the rate of heat release of burning objects. Further, the hot layer ignites the cable trays on the opposite wall of the tunnel after 45 minutes. It is estimated that the sprinkler heads would be activated at 20-22 minutes near the fire source and at 24-28 minutes little further from the fire source when fast sprinkler heads are used. The slow heads are activated between 26-32 minutes. (orig.)

  15. Validation process of ISIS CFD software for fire simulation

    Energy Technology Data Exchange (ETDEWEB)

    Lapuerta, C., E-mail: celine.lapuerta@irsn.fr [Institut de Radioprotection et de Surete Nucleaire (IRSN), BP3, 13115 Saint Paul-lez-Durance (France); ETIC Laboratory, IRSN-CNRS-UAM (I,II), 5 rue Enrico Fermi, 13453 Marseille Cedex 13 (France); Suard, S., E-mail: sylvain.suard@irsn.fr [Institut de Radioprotection et de Surete Nucleaire (IRSN), BP3, 13115 Saint Paul-lez-Durance (France); ETIC Laboratory, IRSN-CNRS-UAM (I,II), 5 rue Enrico Fermi, 13453 Marseille Cedex 13 (France); Babik, F., E-mail: fabrice.babik@irsn.fr [Institut de Radioprotection et de Surete Nucleaire (IRSN), BP3, 13115 Saint Paul-lez-Durance (France); Rigollet, L., E-mail: laurence.rigollet@irsn.fr [Institut de Radioprotection et de Surete Nucleaire (IRSN), BP3, 13115 Saint Paul-lez-Durance (France); ETIC Laboratory, IRSN-CNRS-UAM (I,II), 5 rue Enrico Fermi, 13453 Marseille Cedex 13 (France)

    2012-12-15

    Fire propagation constitutes a major safety concern in nuclear facilities. In this context, IRSN is developing a CFD code, named ISIS, dedicated to fire simulations. This software is based on a coherent set of models that can be used to describe a fire in large, mechanically ventilated compartments. The system of balance equations obtained by combining these models is discretized in time using fractional step methods, including a pressure correction technique for solving hydrodynamic equations. Discretization in space combines two techniques, each proven in the relevant context: mixed finite elements for hydrodynamic equations and finite volumes for transport equations. ISIS is currently in an advanced stage of verification and validation. The results obtained for a full-scale fire test performed at IRSN are presented.

  16. Simulation and Study of Natural Fire in a Wide-Framed Multipurpose Hall with Steel Roof Trusses

    Directory of Open Access Journals (Sweden)

    D. Pada

    2009-01-01

    Full Text Available In this case study, the structural fire safety of unprotected steel roof trusses in a wide-framed multipurpose hall was evaluated according to the natural fire safety concept. The design fires were simulated with FDS in order to determine the temperature development inside the hall. The temperature of the steel was calculated based on the results from the simulation and the structural analysis was carried out in Robot. It was established that the steel roof trusses could be left unprotected under certain conditions, however, a more violent design fire resulted in failure of the truss. 

  17. Fire in the Brazilian Amazon: A Spatially Explicit Model for Policy Impact Analysis

    Science.gov (United States)

    Arima, Eugenio Y.; Simmons, Cynthia S.; Walker, Robert T.; Cochrane, Mark A.

    2007-01-01

    This article implements a spatially explicit model to estimate the probability of forest and agricultural fires in the Brazilian Amazon. We innovate by using variables that reflect farmgate prices of beef and soy, and also provide a conceptual model of managed and unmanaged fires in order to simulate the impact of road paving, cattle exports, and conservation area designation on the occurrence of fire. Our analysis shows that fire is positively correlated with the price of beef and soy, and that the creation of new conservation units may offset the negative environmental impacts caused by the increasing number of fire events associated with early stages of frontier development.

  18. Analysis of Spatio-Temporal Data for Forest Fire Control

    OpenAIRE

    Xiong, Yi

    2015-01-01

    This project aims to establish the relationship of forest fire behavior with ecological/environmental factors, such as forest structure and weather. We analyze records of forest fires during the fire season (May to September) in 1992 from the Forest Fire Management Branch of Ontario Ministry of Natural Resource (OMNR). We start with a preliminary analysis of the data, which includes a descriptive summary and an ordinary linear regression analysis with fire duration as the response. The prelim...

  19. Fire Hazards Analysis for the Inactive Equipment Storage Sprung Structure

    International Nuclear Information System (INIS)

    The purpose of the analysis is to comprehensively assess the risk from fire within individual fire areas in relation to proposed fire protection so as to ascertain whether the fire protection objective of DOE Order 5480.1A are met. The order acknowledges a graded approach commensurate with the hazards involved

  20. Fire risk analysis in ITER tritium building

    International Nuclear Information System (INIS)

    Events as fire have been considered in ITER documentation of low probability and a general approach has been defined to be developed later for the ITER Specific site. It was said that These hazards will be treated according to the industrial safety regulations and practices of the host country. In the framework of studies for the European ITER site in Cadarache, an assessment of fire hazard has been done in order to ensure compliance with French safety requirements. In this report a summary of existing laws is presented and an example of the deterministic approach to be followed for the Preliminary Safety Report is given on the analysis of Tritium building design. (authors)

  1. Experimental determination of the shipboard fire environment for simulated radioactive material packages

    International Nuclear Information System (INIS)

    A series of eight fire tests with simulated radioactive material shipping containers aboard the test ship Mayo Lykes, a break-bulk freighter, is described. The tests simulate three basic types of fires: engine room fires, cargo fires and open pool fires. Detailed results from the tests include temperatures, heat fluxes and air flows measured during the fires. The first examination of the results indicates that shipboard fires are not significantly different from fires encountered in land transport. 13 refs., 15 figs., 11 tabs

  2. Calibration of FARSITE fire area simulator in Iranian northern forests

    OpenAIRE

    Jahdi, R.; Salis, M. (Miguel) de; A. A. Darvishsefat; F. J. Alcasena Urdiroz; Etemad, V.; Mostafavi, M. A.; O. M. Lozano; D. Spano

    2014-01-01

    Wildfire simulators based on empirical or physical models need to be locally calibrated and validated when used under conditions that differ from those where the simulators were originally developed. This study aims to calibrate FARSITE fire spread model considering a set of recent wildfires occurred in Northern Iran forests. Site specific fuel models in the study areas were selected by sampling the main natural vegetation type complexes and assigning standa...

  3. Analysis of NASA JP-4 fire tests data and development of a simple fire model

    Science.gov (United States)

    Raj, P.

    1980-01-01

    The temperature, velocity and species concentration data obtained during the NASA fire tests (3m, 7.5m and 15m diameter JP-4 fires) were analyzed. Utilizing the data analysis, a sample theoretical model was formulated to predict the temperature and velocity profiles in JP-4 fires. The theoretical model, which does not take into account the detailed chemistry of combustion, is capable of predicting the extent of necking of the fire near its base.

  4. Numerical simulation of a full scale fire test on a loaded steel framework

    OpenAIRE

    Franssen, Jean-Marc; Cooke, C. M. E.; Latham, D. J.

    1995-01-01

    A single bay single storey steel portal frame has been tested under fire conditions. It is here simulated using hte non linear computer code CEFICOSS. The elements have composite steel-concrete sections for the thermal analysis, but only the steel part of the sections is load bearing.

  5. Simulation of evacuation behaviors in fire using spacial grid

    Institute of Scientific and Technical Information of China (English)

    YANG Lizhong; ZHAO Daoliang; LI Jian; FANG Weifeng; FAN Weicheng

    2004-01-01

    A two-dimensional Cellular Automata (CA) model to demonstrate the special phenomena of occupants evacuating from fire room is presented. A set of simple but effective models is proposed to investigate the effect of fire smoke on route choice. The concept of danger grade is introduced, and occupants select the target cell according to the value of danger grade at each time step. Some technique is introduced to substitute the human intelligence, such as premeditation. The simulation results show that human evacuation is influenced greatly by both human visual field and building exit.

  6. WIPP fire hazards and risk analysis

    International Nuclear Information System (INIS)

    The purpose of this analysis was to conduct a fire hazards risk analysis of the Transuranic (TRU) contact-handled waste receipt, emplacement, and disposal activities at the Waste Isolation Pilot Plant (WIPP). The technical bases and safety envelope for these operations are defined in the approved WIPP Final Safety Analysis Report (FSAR). Although the safety documentation for the initial phase of the Test Program, the dry bin scale tests, has not yet been approved by the Department of Energy (DOE), reviews of the draft to date, including those by the Advisory Committee on Nuclear Facility Safety (ACNFS), have concluded that the dry bin scale tests present no significant risks in excess of those estimated in the approved WIPP FSAR. It is the opinion of the authors and reviewers of this analysis, based on sound engineering judgment and knowledge of the WIPP operations, that a Fire Hazards and Risk Analysis specific to the dry bin scale test program is not warranted prior to first waste receipt. This conclusion is further supported by the risk analysis presented in this document which demonstrates the level of risk to WIPP operations posed by fire to be extremely low. 15 refs., 41 figs., 48 tabs

  7. Oblique electron fire hose instability: Particle-in-cell simulations

    Science.gov (United States)

    Hellinger, Petr; Trávníček, Pavel M.; Decyk, Victor K.; Schriver, David

    2014-01-01

    Nonlinear properties of the oblique resonant electron fire hose instability are investigated using two-dimensional particle-in-cell simulations in the Darwin approximation for weak initial growth rates. The weak electron fire hose instability has a self-destructive nonlinear behavior; it destabilizes a nonpropagating branch which only exists for a sufficiently strong temperature anisotropy. The nonlinear evolution leads to generation of nonpropagating waves which in turn scatter electrons and reduce their temperature anisotropy. As the temperature anisotropy is being reduced, the nonpropagating branch disappears and the generated standing waves are transformed to propagating whistler waves which are rapidly damped. Consequently, the oblique electron fire hose efficiently reduces the electron temperature anisotropy.

  8. FIRE simulations: galactic outflows and their consequences

    Science.gov (United States)

    Keres, Dusan; FIRE team

    2016-06-01

    We study gaseous outflows and their consequences in high-resolution galaxy formation simulations with explicit stellar feedback from the Feedback in Realistic Environments project. Collective, galaxy scale, effect of stellar feedback results in episodic ejections of large amount of gas and heavy elements into the circum-galactic medium. Gas ejection episodes follow strong bursts of star formation. Properties of galactic star formation and ejection episodes depend on galaxy mass and redshift and, together with gas infall and recycling, shape the evolution of the circum-galactic medium and galaxies. As a consequence, our simulated galaxies have masses, star formation histories and heavy element content in good agreement with the observed population of galaxies.

  9. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels; Karstensen, C.

    2003-01-01

    A model for a flue gas boiler covering the flue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been defined for the furnace, the convection zone (split in 2: a...... zone submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic-Equation system (DAE). Subsequently Mat......Lab/Simulink has been applied for carrying out the simulations. To be able to verify the simulated results experiments has been carried out on a full scale boiler plant....

  10. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

    Sørensen, Kim; Karstensen, Claus; Condra, Thomas Joseph; Houbak, Niels

    2003-01-01

    A model for a ue gas boiler covering the ue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been dened for the furnace, the convection zone (split in 2: a zone...... submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic- Equation system (DAE). Subsequently MatLab/Simulink has...... been applied for carrying out the simulations. To be able to verify the simulated results an experiments has been carried out on a full scale boiler plant....

  11. Trends in fire emissions over the 20th century as simulated by a fire model within CLM-CN

    Science.gov (United States)

    Kloster, S.; Randerson, J. T.; Mahowald, N. M.; Thornton, P. E.

    2009-12-01

    Fire is an important Earth System process, which impacts climate via multiply processes, including atmospheric chemistry, aerosols, land surface properties and the carbon cycle. For recent fires, we have the capacity to observe global fire activity from space. However, historical information on fires is still very incomplete and little is known about the single driving forces of global fire activity. Here we present results from a fire model included in CLM-CN based on the work by Arora and Boer (2005) extended by an explicit parametrization of human ignition and fire suppression as a function of population density. In addition to natural fires we also take into account deforestation fires. We evaluated the model against contemporary satellite fire records and applied it in transient simulations running from 1798 to 2004. Several sensitivity experiments were performed to disentangle the importance of single driving forces impacting fire emissions, such as land use change and wood harvest, changes in population density and changes in climate. Globally we find decreasing fire emissions caused by land use change and wood harvest over the 20th century. The increase in population density over the last century leads to an increase in fire emissions. However, when we also take into account fire suppression, only little change in fire emissions on the global scale is found. Climate change over the last three decades leads to slightly increasing fire emissions. However, larger differences are found on the regional scale. Combining all single driving forces we find decreasing carbon emissions between 1900 and 1970 followed by a pronounced increase in the last three decades on the global scale. Thereby, the importance of the single driving forces for the simulated trend over the 20th century varies considerably for different regions.

  12. Time fluctuation analysis of forest fire sequences

    Science.gov (United States)

    Vega Orozco, Carmen D.; Kanevski, Mikhaïl; Tonini, Marj; Golay, Jean; Pereira, Mário J. G.

    2013-04-01

    Forest fires are complex events involving both space and time fluctuations. Understanding of their dynamics and pattern distribution is of great importance in order to improve the resource allocation and support fire management actions at local and global levels. This study aims at characterizing the temporal fluctuations of forest fire sequences observed in Portugal, which is the country that holds the largest wildfire land dataset in Europe. This research applies several exploratory data analysis measures to 302,000 forest fires occurred from 1980 to 2007. The applied clustering measures are: Morisita clustering index, fractal and multifractal dimensions (box-counting), Ripley's K-function, Allan Factor, and variography. These algorithms enable a global time structural analysis describing the degree of clustering of a point pattern and defining whether the observed events occur randomly, in clusters or in a regular pattern. The considered methods are of general importance and can be used for other spatio-temporal events (i.e. crime, epidemiology, biodiversity, geomarketing, etc.). An important contribution of this research deals with the analysis and estimation of local measures of clustering that helps understanding their temporal structure. Each measure is described and executed for the raw data (forest fires geo-database) and results are compared to reference patterns generated under the null hypothesis of randomness (Poisson processes) embedded in the same time period of the raw data. This comparison enables estimating the degree of the deviation of the real data from a Poisson process. Generalizations to functional measures of these clustering methods, taking into account the phenomena, were also applied and adapted to detect time dependences in a measured variable (i.e. burned area). The time clustering of the raw data is compared several times with the Poisson processes at different thresholds of the measured function. Then, the clustering measure value

  13. New tendencies in wildland fire simulation for understanding fire phenomena: An overview of the WFDS system capabilities in Mediterranean ecosystems

    Science.gov (United States)

    Pastor, E.; Tarragó, D.; Planas, E.

    2012-04-01

    Wildfire theoretical modeling endeavors predicting fire behavior characteristics, such as the rate of spread, the flames geometry and the energy released by the fire front by applying the physics and the chemistry laws that govern fire phenomena. Its ultimate aim is to help fire managers to improve fire prevention and suppression and hence reducing damage to population and protecting ecosystems. WFDS is a 3D computational fluid dynamics (CFD) model of a fire-driven flow. It is particularly appropriate for predicting the fire behaviour burning through the wildland-urban interface, since it is able to predict the fire behaviour in the intermix of vegetative and structural fuels that comprise the wildland urban interface. This model is not suitable for operational fire management yet due to computational costs constrains, but given the fact that it is open-source and that it has a detailed description of the fuels and of the combustion and heat transfer mechanisms it is currently a suitable system for research purposes. In this paper we present the most important characteristics of the WFDS simulation tool in terms of the models implemented, the input information required and the outputs that the simulator gives useful for understanding fire phenomena. We briefly discuss its advantages and opportunities through some simulation exercises of Mediterranean ecosystems.

  14. Fire hazard analysis of the radioactive mixed waste trenchs

    International Nuclear Information System (INIS)

    This Fire Hazards Analysis (FHA) is intended to assess comprehensively the risk from fire associated with the disposal of low level radioactive mixed waste in trenches within the lined landfills, provided by Project W-025, designated Trench 31 and 34 of the Burial Ground 218-W-5. Elements within the FHA make recommendations for minimizing risk to workers, the public, and the environment from fire during the course of the operation's activity. Transient flammables and combustibles present that support the operation's activity are considered and included in the analysis. The graded FHA contains the following elements: description of construction, protection of essential safety class equipment, fire protection features, description of fire hazards, life safety considerations, critical process equipment, high value property, damage potential--maximum credible fire loss (MCFL) and maximum possible fire loss (MPFL), fire department/brigade response, recovery potential, potential for a toxic, biological and/or radiation incident due to a fire, emergency planning, security considerations related to fire protection, natural hazards (earthquake, flood, wind) impact on fire safety, and exposure fire potential, including the potential for fire spread between fire areas. Recommendations for limiting risk are made in the text of this report and printed in bold type. All recommendations are repeated in a list in Section 18.0

  15. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2003-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supple-mentary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, sup-plementary firing is expected to...... the recu-perated gas turbine. Instead, other process changes may be considered in order to obtain a high marginal efficiency on natural gas. Two possibilities are discussed: Integration between an IFGT and pyrolysis of the biofuel which will result in a highly efficient utilization of the biomass, and...... indirectly fired gas turbine (IFGT) and for the supplementary-fired IFGT. These results show that the combination of external firing and internal firing have the potential of reducing or solving some problems associated with the use of biomass both in the recuperated and the indirectly fired gas turbine: The...

  16. Physics Basis and Simulation of Burning Plasma Physics for the Fusion Ignition Research Experiment (FIRE)

    International Nuclear Information System (INIS)

    The FIRE [Fusion Ignition Research Experiment] design for a burning plasma experiment is described in terms of its physics basis and engineering features. Systems analysis indicates that the device has a wide operating space to accomplish its mission, both for the ELMing H-mode reference and the high bootstrap current/high beta advanced tokamak regimes. Simulations with 1.5D transport codes reported here both confirm and constrain the systems projections. Experimental and theoretical results are used to establish the basis for successful burning plasma experiments in FIRE

  17. Nuclear power plant fire protection: philosophy and analysis

    International Nuclear Information System (INIS)

    This report combines a fire severity analysis technique with a fault tree methodology for assessing the importance to nuclear power plant safety of certain combinations of components and systems. Characteristics unique to fire, such as propagation induced by the failure of barriers, have been incorporated into the methodology. By applying the resulting fire analysis technique to actual conditions found in a representative nuclear power plant, it is found that some safety and nonsafety areas are both highly vulnerable to fire spread and impotant to overall safety, while other areas prove to be of marginal importance. Suggestions are made for further experimental and analytical work to supplement the fire analysis method

  18. Examining fuel treatment longevity through experimental and simulated surface fire behaviour: a maritime pine case study

    OpenAIRE

    Fernandes, Paulo

    2009-01-01

    The adequate prediction of fire behaviour characteristics for both scientific and management objectives is greatly impacted by the performance of fire behaviour models. Lack of experimentation and limitations in fire behaviour models are constraining our current understanding of fuel treatment effectiveness and longevity. The residual effect of a 10-year old prescribed fire treatment is quantified by simulating and observing actual real-world fire behaviour in treated (T10) and untreated (U25...

  19. A Contextual Fire Detection Algorithm for Simulated HJ-1B Imagery

    Directory of Open Access Journals (Sweden)

    Xiangsheng Kong

    2009-02-01

    Full Text Available The HJ-1B satellite, which was launched on September 6, 2008, is one of the small ones placed in the constellation for disaster prediction and monitoring. HJ-1B imagery was simulated in this paper, which contains fires of various sizes and temperatures in a wide range of terrestrial biomes and climates, including RED, NIR, MIR and TIR channels. Based on the MODIS version 4 contextual algorithm and the characteristics of HJ-1B sensor, a contextual fire detection algorithm was proposed and tested using simulated HJ-1B data. It was evaluated by the probability of fire detection and false alarm as functions of fire temperature and fire area. Results indicate that when the simulated fire area is larger than 45 m2 and the simulated fire temperature is larger than 800 K, the algorithm has a higher probability of detection. But if the simulated fire area is smaller than 10 m2, only when the simulated fire temperature is larger than 900 K, may the fire be detected. For fire areas about 100 m2, the proposed algorithm has a higher detection probability than that of the MODIS product. Finally, the omission and commission error were evaluated which are important factors to affect the performance of this algorithm. It has been demonstrated that HJ-1B satellite data are much sensitive to smaller and cooler fires than MODIS or AVHRR data and the improved capabilities of HJ-1B data will offer a fine opportunity for the fire detection.

  20. Fire simulation in nuclear facilities--the FIRAC code and supporting experiments

    International Nuclear Information System (INIS)

    The fire accident analysis computer code FIRAC was designed to estimate radioactive and nonradioactive source terms and predict fire-induced flows and thermal and material transport within the ventilation systems of nuclear fuel cycle facilities. FIRAC maintains its basic structure and features and has been expanded and modified to include the capabilities of the zone-type compartment fire model computer code FIRIN developed by Battelle Pacific Northwest Laboratory. The two codes have been coupled to provide an improved simulation of a fire-induced transient within a facility. The basic material transport capability of FIRAC has been retained and includes estimates of entrainment, convection, deposition, and filtration of material. The interrelated effects of filter plugging, heat transfer, gas dynamics, material transport, and fire and radioactive source terms also can be simulated. Also, a sample calculation has been performed to illustrate some of the capabilities of the code and how a typical facility is modeled with FIRAC. In addition to the analytical work being performed at Los Alamos, experiments are being conducted at the New Mexico State University to support the FIRAC computer code development and verification. This paper summarizes two areas of the experimental work that support the material transport capabilities of the code: the plugging of high-efficiency particulate air (HEPA) filters by combustion aerosols and the transport and deposition of smoke in ventilation system ductwork

  1. Fire simulation in nuclear facilities: the FIRAC code and supporting experiments

    International Nuclear Information System (INIS)

    The fire accident analysis computer code FIRAC was designed to estimate radioactive and nonradioactive source terms and predict fire-induced flows and thermal and material transport within the ventilation systems of nuclear fuel cycle facilities. FIRAC maintains its basic structure and features and has been expanded and modified to include the capabilities of the zone-type compartment fire model computer code FIRIN developed by Battelle Pacific Northwest Laboratory. The two codes have been coupled to provide an improved simulation of a fire-induced transient within a facility. The basic material transport capability of FIRAC has been retained and includes estimates of entrainment, convection, deposition, and filtration of material. The interrelated effects of filter plugging, heat transfer, gas dynamics, material transport, and fire and radioactive source terms also can be simulated. Also, a sample calculation has been performed to illustrate some of the capabilities of the code and how a typical facility is modeled with FIRAC. In addition to the analytical work being performed at Los Alamos, experiments are being conducted at the New Mexico State University to support the FIRAC computer code development and verification. This paper summarizes two areas of the experimental work that support the material transport capabiities of the code: the plugging of high-efficiency particulate air (HEPA) filters by combustion aerosols and the transport and deposition of smoke in ventilation system ductwork

  2. Statistical analysis of fire events at US nuclear power plants

    International Nuclear Information System (INIS)

    The concern about fires as a potential agent of common cause failure in NPPs has greatly increased since the Browns Ferry NPP fire. Several regulatory actions were initiated following this incident. In investigating the chances of fire incident leading to core melt it is found that the unconditional frequency is about 1x10 incidents per reactor-year. The detailed reviews of fire events at nuclear plants are used in quantifying fire occurrence frequency required to carry out fire risk assessment. In this work the results of a statistical analysis of 354 fire incidents at US NPPs in the period from January 1965 to June 1985 are presented to quantify fire occurrence frequency. The distribution of fire incidents between the different types of NPPs (PWR, BWR or HTGR), the mode of plant operation, the probable cause of fire, the type of detectors detect the incident, who extinguished the fire, suppression equipment, suppression agent, the initiating combustible, the component or components affected by fire are all analysed for the studied 354 fire incidents. More than 50% of the incidents occurred during the construction phase, in many of them there is neither nuclear problem nor any safety problem, however these incidents delayed the startup of the units up to 2 years as happened in Indian Point unit 2 (1971). There are four major fire incidents at US NPPS in the first period of the study (1965-1978), not one of them in the last seven years (1979-1985) which clarify the development in the fire protection measures and technology. The fire events in US (NPPS) can be summarized in about 354 incidents at 33 locations due to 38 causes of fire with 0.17 fire events/plant/year

  3. Fire risk assessment and computer simulation of fire scenario in underground mines

    OpenAIRE

    Adjiski, Vanco; Despodov, Zoran; Mirakovski, Dejan; Mijalkovski, Stojance

    2015-01-01

    Unsafe working conditions in underground mines have led to a number of accidents, loss of life, damage to property, interruption of production, etc. Safety is essential in mining industry, which in recent years mainly focuses on injury prevention in the workplace through a variety of procedures and employee training. The primary goal of this paper is to present a methodology with systematic analysis to determine the most risky places for fire occurrence in underground mines an...

  4. SYNTHESIS OF SAFETY ANALYSIS AND FIRE HAZARD ANALYSIS METHODOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Coutts, D

    2007-04-17

    Successful implementation of both the nuclear safety program and fire protection program is best accomplished using a coordinated process that relies on sound technical approaches. When systematically prepared, the documented safety analysis (DSA) and fire hazard analysis (FHA) can present a consistent technical basis that streamlines implementation. If not coordinated, the DSA and FHA can present inconsistent conclusions, which can create unnecessary confusion and can promulgate a negative safety perception. This paper will compare the scope, purpose, and analysis techniques for DSAs and FHAs. It will also consolidate several lessons-learned papers on this topic, which were prepared in the 1990s.

  5. Improvement of fire protection measures for nuclear power plants

    International Nuclear Information System (INIS)

    Improvements of fire protection measures for nuclear power plants were performed as following items: Development of fire hazard analysis method. Application of developed Fire Dynamic tool to actual plants, With regard to fire tests for the fire data acquisition, cable fire test and oil fire test were performed. Implementation of fire hazard analysis code and simulation were performed as following items: Fire analysis codes FDS, SYLVIA, CFAST were implemented in order to analyze the fire progression phenomena, Trial simulation of fire hazard as Metal-Clad Switch Gear Fire of ONAGAWA NPP in Tohoku earthquake (HEAF accident). (author)

  6. Fire simulation of the canister transfer and installation vehicle; Kapselin siirto- ja asennusajoneuvon palosimulointi

    Energy Technology Data Exchange (ETDEWEB)

    Peltokorpi, L. [Fortum Power and Heat Oy, Espoo (Finland)

    2012-12-15

    A pyrolysis model of the canister transfer and installation vehicle was developed and vehicle fires in the final disposal tunnel and in the central tunnel were simulated using the fire simulation program FDS (Fire Dynamics Simulator). For comparison, same vehicle fire was also simulated at conditions in which the fire remained as a fuel controlled during the whole simulation. The purpose of the fire simulations was to simulate the fire behaviour realistically taking into account for example the limitations coming from the lack of oxygen. The material parameters for the rubber were defined and the simulation models for the tyres developed by simulating the fire test of a front wheel loader rubber tyre done by SP Technical Research Institute of Sweden. In these simulations the most important phenomena were successfully brought out but the timing of the phenomena was difficult. The final values for the rubber material parameters were chosen so that the simulated fire behaviour was at least as intense as the measured one. In the vehicle fire simulations a hydraulic oil or diesel leak causing a pool fire size of 2 MW and 2 m{sup 2} was assumed. The pool fire was assumed to be located under the tyres of the SPMT (Self Propelled Modular Transporters) transporter. In each of the vehicle fire simulations only the tyres of the SPMT transporter were observed to be burning whereas the tyres of the trailer remained untouched. In the fuel controlled fire the maximum power was slightly under 10 MW which was reached in about 18 minutes. In the final disposal tunnel the growth of the fire was limited due to the lack of oxygen and the relatively fast air flows existing in the tunnel. Fast air flows caused the flame spreading to be limited to the certain directions. In the final disposal tunnel fire the maximum power was slightly over 7 MW which was reached about 8 minutes after the ignition. In the central tunnel there was no shortage of oxygen but the spread of the fire was limited

  7. Analysis of sodium pool fire in SFEF for assessing the limiting pool fire

    International Nuclear Information System (INIS)

    Accidental sodium leaks and resultant sodium fires in Liquid Metal Fast Breeder Reactor (LMFBR) systems can create a threat to the safe operation of the plant. To avoid this defence-in depth approach is implemented from the design stage of reactor itself. Rapid detection of sodium leak and fast dumping of the sodium into the storage tank of a defective circuit, leak collection trays, adequate lining of load bearing structural concrete and extinguishment of the sodium fire are the important defensive measures in the design, construction and operation of a LMFBR for protection against sodium leaks and their resultant fires. Evaluation of sodium leak events and their consequences by conducting large scale engineering experiments is very essential for effective implementation of the above protection measures for sodium fire safety. For this purpose a Sodium Fire Experimental Facility (SFEF) is constructed at SED, IGCAR. SFEF is having an experimental hall of size 9 m x 6 m x 10 m with 540 m3 volume and its design pressure is 50 kPa. It is a concrete structure and provided with SS 304 liner, which is fixed to the inside surfaces of walls, ceiling and floor. A leak tight door of size (1.8 m x 2.0 m) is provided to the experimental hall and the facility is provided with a sodium equipment hall and a control room. Experimental evaluation of sodium pool fire consequences is an important activity in the LMFBR sodium fire safety related studies. An experimental program has been planned for different types of sodium fire studies in SFEF. A prior to that numerical analysis have been carried out for enclosed sodium pool fires using SOFIRE-II sodium pool fire code for SFEF experimental hall configuration to evaluate the limiting pool fire. This paper brings out results of the analysis carried out for this purpose. Limiting pool fire of SFEF depends on the exposed surface area of the pool, amount of sodium in the pool, oxygen concentration and initial sodium temperature. Limiting

  8. Simulation of Quaking Aspen Potential Fire Behavior in Northern Utah, USA

    Directory of Open Access Journals (Sweden)

    R. Justin DeRose

    2014-12-01

    Full Text Available Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and Fuels Extension. The wind speeds necessary for crowning (crown-to-crown fire spread and torching (surface to crown fire spread were evaluated to test the hypothesis that predicted fire behavior is influenced by the proportion of aspen in the stand. Results showed a strong effect of species composition on crowning, but only under moderate fire weather, where aspen-dominated stands were unlikely to crown or torch. Although rarely observed in actual fires, conifer-dominated stands were likely to crown but not to torch, an example of “hysteresis” in crown fire behavior. Results support the hypothesis that potential crown fire behavior varies across a gradient of aspen dominance and fire weather, where it was likely under extreme and severe fire weather, and unlikely under moderate and high fire weather. Furthermore, the “fire-proof” nature of aspen stands broke down across the gradient of aspen dominance and fire weather.

  9. CFD simulation of production of NOx in coal-fired furnaces

    OpenAIRE

    ASKAROVA ALIYA; BOLEGENOVA SALTANAT; MAXIMOV VALERY; OSPANOVA SHYNAR; BOLEGENOVA SYMBAT

    2016-01-01

    Computational fluid dynamics (CFD) has been accepted as a powerful and effective tool for control and analysis of coal-fired utility boilers. Since coal burning in a utility boilers is a very complex process that comprises high-temperature reacting turbulent flow, particles transport and radiative heat transfer a reliable numerical simulation models of coal combustion requires high accuracy and careful interpretation of its numerical results.

  10. 324 Building fire hazards analysis implementation plan

    International Nuclear Information System (INIS)

    In March 1998, the 324 Building Fire Hazards Analysis (FHA) (Reference 1) was approved by the US Department of Energy, Richland Operations Office (DOE-RL) for implementation by B and W Hanford Company (BWHC). The purpose of the FHA was to identify gaps in compliance with DOE Order 5480.7A (Reference 2) and Richland Operations Office Implementation Directive (RLID) 5480.7 (Reference 3), especially in regard to loss limitation. The FHA identified compliance gaps in six areas and provided 20 recommendations to bring the 324 Building into compliance with DOE Order 5480.7A. Additionally, one observation was provided. To date, four of the recommendations and the one observation have been completed. Actions identified for seven of the recommendations are currently in progress. Exemption requests will be transmitted to DOE-RL for three of the recommendations. Six of the recommendations are related to future shut down activities of the facility and the corrective actions are not being addressed as part of this plan. The actions for recommendations associated with the safety related part of the 324 Building and operation of the cells and support areas were evaluated using the Unreviewed Safety Question (USQ) process. Major Life Safety Code concerns have been corrected. The status of the recommendations and actions was confirmed during the July 1998 Fire Protection Assessment. BVMC will use this Implementation Plan to bring the 324 Building and its operation into compliance with DOE Order 5480.7A and RLID 5480.7

  11. 327 Building fire hazards analysis implementation plan

    International Nuclear Information System (INIS)

    In March 1998, the 327 Building Fire Hazards Analysis (FRA) (Reference 1) was approved by the US Department of Energy, Richland Operations Office (DOE-RL) for implementation by B and W Hanford Company (B and WHC). The purpose of the FHA was to identify gaps in compliance with DOE Order 5480.7A (Reference 2) and Richland Operations Office Implementation Directive (RLID) 5480.7 (Reference 3), especially in regard to loss limitation. The FHA identified compliance gaps in five areas and provided nine recommendations (11 items) to bring the 327 Building into compliance. To date, actions for five of the 11 items have been completed. Exemption requests will be transmitted to DOE-RL for two of the items. Corrective actions have been identified for the remaining four items. The completed actions address combustible loading requirements associated with the operation of the cells and support areas. The status of the recommendations and actions was confirmed during the July 1998 Fire Protection Assessment. B and WHC will use this Implementation Plan to bring the 327 Building and its operation into compliance with DOE Order 5480.7A and RLID 5480.7

  12. Fire-accident analysis code (FIRAC) verification

    International Nuclear Information System (INIS)

    The FIRAC computer code predicts fire-induced transients in nuclear fuel cycle facility ventilation systems. FIRAC calculates simultaneously the gas-dynamic, material transport, and heat transport transients that occur in any arbitrarily connected network system subjected to a fire. The network system may include ventilation components such as filters, dampers, ducts, and blowers. These components are connected to rooms and corridors to complete the network for moving air through the facility. An experimental ventilation system has been constructed to verify FIRAC and other accident analysis codes. The design emphasizes network system characteristics and includes multiple chambers, ducts, blowers, dampers, and filters. A large industrial heater and a commercial dust feeder are used to inject thermal energy and aerosol mass. The facility is instrumented to measure volumetric flow rate, temperature, pressure, and aerosol concentration throughout the system. Aerosol release rates and mass accumulation on filters also are measured. This paper compares and discusses the gas-dynamic and heat transport data obtained from the ventilation system experiments with those predicted by the FIRAC code. The numerically predicted data generally are within 10% of the experimental data

  13. Forest fire propagation simulations for a risk assessment methodology development for a nuclear power plant

    OpenAIRE

    Yasushi Okano; Hidemasa Yamano

    2015-01-01

    After the Fukushima Daiichi nuclear power plant [NPP] accident, there has been an increased concern with the safety of NPPs in terms of external hazards, one of which is a forest fire which can create potential challenges to safety functions and the structural integrity of an NPP. As a part of the development of a risk assessment methodology for forest fires as an external hazard, forest fire propagation simulations have been performed by using the FARSITE simulator. These simulations have be...

  14. Root cause analysis for fire events at nuclear power plants

    International Nuclear Information System (INIS)

    Fire hazard has been identified as a major contributor to a plant' operational safety risk. The International nuclear power community (regulators, operators, designers) has been studying and developing tools for defending against this hazed. Considerable advances have been achieved during past two decades in design and regulatory requirements for fire safety, fire protection technology and related analytical techniques. The IAEA endeavours to provide assistance to Member States in improving fire safety in nuclear power plants. A task was launched by IAEA in 1993 with the purpose to develop guidelines and good practices, to promote advanced fire safety assessment techniques, to exchange state of the art information, and to provide engineering safety advisory services and training in the implementation of internationally accepted practices. This TECDOC addresses a systematic assessment of fire events using the root cause analysis methodology, which is recognized as an important element of fire safety assessment

  15. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2002-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indirectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supplementary firing may be based on natural gas, biogas, or pyrolysis gas. {The interest in this cycle arise from a recent...... requires a clean, expensive fuel. The latter is limited in efficiency due to limitations in material temperature of the heat exchanger. Thus, in the case of an IBFGT, it would be very appropriate to use a cheap biomass or waste fuel for low temperature combustion and external firing and use natural gas at...... analysed: Integration between an IFGT and pyrolysis of the biofuel which will result in a highly efficient utilization of the biomass, and integration between external biomass firing, internal biomass firing and internal natural gas firing. The marginal efficiency of the natural gas is in this case found...

  16. Advanced analysis and design for fire safety of steel structures

    CERN Document Server

    Li, Guoqiang

    2013-01-01

    Advanced Analysis and Design for Fire Safety of Steel Structures systematically presents the latest findings on behaviours of steel structural components in a fire, such as the catenary actions of restrained steel beams, the design methods for restrained steel columns, and the membrane actions of concrete floor slabs with steel decks. Using a systematic description of structural fire safety engineering principles, the authors illustrate the important difference between behaviours of an isolated structural element and the restrained component in a complete structure under fire conditions. The book will be an essential resource for structural engineers who wish to improve their understanding of steel buildings exposed to fires. It is also an ideal textbook for introductory courses in fire safety for master’s degree programs in structural engineering, and is excellent reading material for final-year undergraduate students in civil engineering and fire safety engineering. Furthermore, it successfully bridges th...

  17. Fire Hazards Analysis for the 200 Area Interim Storage Area

    International Nuclear Information System (INIS)

    This documents the Fire Hazards Analysis (FHA) for the 200 Area Interim Storage Area. The Interim Storage Cask, Rad-Vault, and NAC-1 Cask are analyzed for fire hazards and the 200 Area Interim Storage Area is assessed according to HNF-PRO-350 and the objectives of DOE Order 5480 7A. This FHA addresses the potential fire hazards associated with the Interim Storage Area (ISA) facility in accordance with the requirements of DOE Order 5480 7A. It is intended to assess the risk from fire to ensure there are no undue fire hazards to site personnel and the public and to ensure property damage potential from fire is within acceptable limits. This FHA will be in the form of a graded approach commensurate with the complexity of the structure or area and the associated fire hazards

  18. Virtual Reality Simulation of Fire Fighting Robot Dynamic and Motion

    CERN Document Server

    Setiawan, Joga D; Budiyono, Agus

    2008-01-01

    This paper presents one approach in designing a Fire Fighting Robot which has been contested annually in a robotic student competition in many countries following the rules initiated at the Trinity College. The approach makes use of computer simulation and animation in a virtual reality environment. In the simulation, the amount of time, starting from home until the flame is destroyed, can be confirmed. The efficacy of algorithms and parameter values employed can be easily evaluated. Rather than spending time building the real robot in a trial and error fashion, now students can explore more variation of algorithm, parameter and sensor-actuator configuration in the early stage of design. Besides providing additional excitement during learning process and enhancing students understanding to the engineering aspects of the design, this approach could become a useful tool to increase the chance of winning the contest.

  19. Hazard Analysis on One—Room Building Fires

    Institute of Scientific and Technical Information of China (English)

    YuDeming; FengChanggen

    1998-01-01

    First,a calculation method for available safety egress time (shortly called ASET) and requirement safety egress time (Shortly called RSET) in a one-room building fire is proposed and a model for predicting the death number caused by the fire is established in this paper,Then,numerical simulations are performed,and the following laws are discovered:(1)At the beginning of the fire,the smoke layer falls slowly;as the fire develops,it falls rapidly.(2) The hypotheses on the fire source,the combustion properties of the combustibles,and the width of the exit and the person number in the room are important factors which affect the death number in the fire.

  20. “Use of fire extinguishers”—a new course with a new simulator

    CERN Multimedia

    HSE Unit & GS/FB

    2012-01-01

    Don’t wait, sign up! A new training course, “Handling of fire extinguishers”, is available since the beginning of March 2012. The training course is given by members of CERN’s Fire Brigade (GS-FB) and is intended for all members of personnel of CERN. Upon successful completion of the training course, you will be able to do the following: recognise a potentially combustible item and the various fire classes; choose the appropriate extinguisher for a given fire class; handle a fire extinguisher properly and efficiently; apply CERN's safety instructions. An important part of the training are the different firefighting exercises conducted using a new simulator, which makes it possible to simulate real conditions such as the following: a fire in the office; a fire in an electrical cabinet; a fire involving chemicals.        Don’t wait:  sign up for the training course directly ...

  1. Location dependent common cause analysis with an application to fires

    International Nuclear Information System (INIS)

    The purpose of the work described is to develop a methodology by which the public risk arising from localized common cause events (e.g., fires) in nuclear plants can be assessed. Attention was paid to maximizing both the completeness and efficiency of the analysis. This methodology was then applied to the analysis of fire events in the Clinch River Breeder Reactor Plant

  2. 3D simulation of Industrial Hall in case of fire. Benchmark between ABAQUS, ANSYS and SAFIR

    OpenAIRE

    Vassart, Olivier; Cajot, Louis-Guy; O'Connor, Marc; Shenkai, Y.; Fraud, C.; Zhao, Bin; De la Quintana, Jesus; Martinez de Aragon, J.; Franssen, Jean-Marc; Gens, Frederic

    2004-01-01

    For simple storey buildings, the structural behaviour in case of fire is relevant only for the safety of the firemen. The protection of occupants and goods is a matter of fire spread, smoke propagation, active fire fighting measures and evacuation facilities. Brittle failure, progressive collapse and partial failure of façades elements outwards may endanger the fire fighters and have to be avoided. In order to deal with such an objective, the simulation softwares has to cover the 3D structura...

  3. Turbulence radiation interaction modeling in hydrocarbon pool fire simulations

    Energy Technology Data Exchange (ETDEWEB)

    BURNS,SHAWN P.

    1999-12-01

    The importance of turbulent fluctuations in temperature and species concentration in thermal radiation transport modeling for combustion applications is well accepted by the radiation transport and combustion communities. A number of experimental and theoretical studies over the last twenty years have shown that fluctuations in the temperature and species concentrations may increase the effective emittance of a turbulent flame by as much as 50% to 300% over the value that would be expected from the mean temperatures and concentrations. With the possibility of such a large effect on the principal mode of heat transfer from a fire, it is extremely important for fire modeling efforts that turbulence radiation interaction be well characterized and possible modeling approaches understood. Toward this end, this report seeks to accomplish three goals. First, the principal turbulence radiation interaction closure terms are defined. Second, an order of magnitude analysis is performed to understand the relative importance of the various closure terms. Finally, the state of the art in turbulence radiation interaction closure modeling is reviewed. Hydrocarbon pool fire applications are of particular interest in this report and this is the perspective from which this review proceeds. Experimental and theoretical analysis suggests that, for this type of heavily sooting flame, the turbulent radiation interaction effect is dominated by the nonlinear dependence of the Planck function on the temperature. Additional effects due to the correlation between turbulent fluctuations in the absorptivity and temperature may be small relative to the Planck function effect for heavily sooting flames. This observation is drawn from a number of experimental and theoretical discussions. Nevertheless, additional analysis and data is needed to validate this observation for heavily sooting buoyancy dominated plumes.

  4. Quantitative analysis of forest fire extinction efficiency

    OpenAIRE

    Miguel E. Castillo-Soto; Francisco Rodríguez-Silva

    2015-01-01

    Aim of study: Evaluate the economic extinction efficiency of forest fires, based on the study of fire combat undertaken by aerial and terrestrial means. Area of study, materials and methods: Approximately 112,000 hectares in Chile. Records of 5,876 forest fires that occurred between 1998 and 2009 were analyzed. The area further provides a validation sector for results, by incorporating databases for the years 2010 and 2012. The criteria used for measuring extinction efficiency were econo...

  5. Experimental measurement of a shipboard fire environment with simulated radioactive materials packages

    International Nuclear Information System (INIS)

    Results from a series of eight test fires ranging in size from 2.2 to 18.8 MW conducted aboard the Coast Guard fire test ship Mayo Lykes at Mobile, Alabama are presented and discussed. Tests aboard the break-bulk type cargo ship consisted of heptane spray fires simulating engine room and galley fires, wood crib fires simulating cargo hold fires, and pool fires staged for comparison to land-based regulatory fire results. Primary instrumentation for the tests consisted of two pipe calorimeters that simulated a typical package shape for radioactive materials packages. The calorimeters were both located adjacent to the fires and on the opposite side of the cargo hold bulkhead nearest the fire. The calorimeters were constructed from 1.5 m length sections of nominal 2 foot diameter schedule 60 steel pipe. Type K thermocouples were attached at 12 locations on the circumference and ends of the calorimeter. Fire heat fluxes to the calorimeter surfaces were estimated with the use of the Sandia SODDIT inverse heat conduction code. Experimental results from all types of tests are discussed, and some comparisons are made between the environments found on the ship and those found in land-based pool fire tests

  6. Decoupled numerical simulation of a solid fuel fired retort boiler

    International Nuclear Information System (INIS)

    The paper deals with numerical simulation of the retort boiler fired with solid fuel. Such constructions are very popular for heating systems and their development is mostly based on the designer experience. The simulations have been done in ANSYS/Fluent package and involved two numerical models. The former deals with a fixed-bed combustion of the solid fuel and free-board gas combustion. Solid fuel combustion is based on the coal kinetic parameters. This model encompasses chemical reactions, radiative heat transfer and turbulence. Coal properties have been defined with user defined functions. The latter model describes flow of water inside a water jacked that surrounds the combustion chamber and flue gas ducts. The novelty of the proposed approach is separating of the combustion simulation from the water flow. Such approach allows for reducing the number of degrees of freedom and thus lowering the necessary numerical effort. Decoupling combustion from water flow requires defining interface boundary condition. As this boundary condition is unknown it is adjusted iteratively. The results of the numerical simulation have been successfully validated against measurement data. - Highlights: • New decoupled modelling of small scale boiler is proposed. • Fixed-bed combustion model based on kinetic parameters is introduced. • Decoupling reduced the complexity of the model and computational time. • Simple and computationally inexpensive coupling algorithm is proposed. • Model is successfully validated against measurements

  7. Fires

    Science.gov (United States)

    Whether a fire happens in your home or in the wild, it can be very dangerous. Fire spreads quickly. There is no time to gather ... a phone call. In just two minutes, a fire can become life-threatening. In five minutes, a ...

  8. Calibrating a forest landscape model to simulate frequent fire in Mediterranean-type shrublands

    Science.gov (United States)

    Syphard, A.D.; Yang, J.; Franklin, J.; He, H.S.; Keeley, J.E.

    2007-01-01

    In Mediterranean-type ecosystems (MTEs), fire disturbance influences the distribution of most plant communities, and altered fire regimes may be more important than climate factors in shaping future MTE vegetation dynamics. Models that simulate the high-frequency fire and post-fire response strategies characteristic of these regions will be important tools for evaluating potential landscape change scenarios. However, few existing models have been designed to simulate these properties over long time frames and broad spatial scales. We refined a landscape disturbance and succession (LANDIS) model to operate on an annual time step and to simulate altered fire regimes in a southern California Mediterranean landscape. After developing a comprehensive set of spatial and non-spatial variables and parameters, we calibrated the model to simulate very high fire frequencies and evaluated the simulations under several parameter scenarios representing hypotheses about system dynamics. The goal was to ensure that observed model behavior would simulate the specified fire regime parameters, and that the predictions were reasonable based on current understanding of community dynamics in the region. After calibration, the two dominant plant functional types responded realistically to different fire regime scenarios. Therefore, this model offers a new alternative for simulating altered fire regimes in MTE landscapes. ?? 2007 Elsevier Ltd. All rights reserved.

  9. Surface Fire Hazards Analysis Technical Report-Constructor Facilities

    International Nuclear Information System (INIS)

    The purpose of this Fire Hazards Analysis Technical Report (hereinafter referred to as Technical Report) is to assess the risk from fire within individual fire areas to ascertain whether the U.S. Department of Energy (DOE) fire safety objectives are met. The objectives identified in DOE Order 420.1, Change 2, Facility Safety, Section 4.2, establish requirements for a comprehensive fire and related hazards protection program for facilities sufficient to minimize the potential for: The occurrence of a fire or related event; A fire that causes an unacceptable on-site or off-site release of hazardous or radiological material that will threaten the health and safety of employees, the public, or the environment; Vital DOE programs suffering unacceptable interruptions as a result of fire and related hazards; Property losses from a fire and related events exceeding defined limits established by DOE; and Critical process controls and safety class systems being damaged as a result of a fire and related events

  10. Comparison of serial and parallel simulations of a corridor fire using FDS

    Science.gov (United States)

    Valasek, L.

    2015-09-01

    Current fire simulators allow to model the course of fire in large areas and its impact on structure and equipment. This paper deals with a comparison of serial and parallel calculations of simulation of a corridor fire by the FDS (Fire Dynamics Simulator) system. In parallel case, the whole computational domain is divided into several computational meshes, the computation on each mesh is considered as a single MPI (Message Passing Interface) process realised on one computational core and communication between MPI processes is provided by MPI. The aim of this paper is to determine the size of error caused by parallelization of computation, which occurs at touches of computational meshes.

  11. ExtendSim’s Simulation Analysis of Combat Efficiency of Rapid-fire Antiaircraft Guns against Supersonic Missiles%速射高炮抗击超音速导弹作战效能ExtendSim仿真分析

    Institute of Scientific and Technical Information of China (English)

    梁甲慧; 季新源; 陈希林

    2014-01-01

    利用ExtendSim仿真平台建立了速射高炮抗击超音速导弹作战效能模型,对模型进行了仿真研究,分析了速射高炮抗击超音速导弹的作战过程,所得结果为速射高炮武器装备发展及其作战运用提供了基本参考和依据。%As a visual simulation platform,the ExtendSim was built to provide a model of combat process of rapid-fire antiaircraft guns defending against supersonic missiles. And the simulation of model was ana-lyzed. The simulation results provide a basic reference for the development and combat application of the rapid-fire antiaircraft weaponry.

  12. Numerical simulation based cold tests for a tangentially fired boiler

    Institute of Scientific and Technical Information of China (English)

    XIANG Yuhua; ZHANG Jiayuan; ZHANG Xiaohui

    2012-01-01

    Such problems as flameout and serious slagging frequently occurred in a 170 t/h tangentially fired boiler burning inferior coals and with low load.Thus,cold tests were carried out to comprehensively investigate the performance of each air tube and the size and position of the tangential circle.Therefore,the cause and area of slagging in furnace can be determined.Thus,by numerical simulation on combustion,the optimal operation parameters for the boiler burning different coals under various loads conditions can be provided.The actual application showed that,the boiler fed with present coal can be long-term operated stably at 60% load,and its heat efficiency was up to 91%.Moreover,the abnormal flameout no longer occurred,and the slagging was alleviated a lot.

  13. The application of super wavelet finite element on temperature-pressure coupled field simulation of LPG tank under jet fire

    Science.gov (United States)

    Zhao, Bin

    2015-02-01

    Temperature-pressure coupled field analysis of liquefied petroleum gas (LPG) tank under jet fire can offer theoretical guidance for preventing the fire accidents of LPG tank, the application of super wavelet finite element on it is studied in depth. First, review of related researches on heat transfer analysis of LPG tank under fire and super wavelet are carried out. Second, basic theory of super wavelet transform is studied. Third, the temperature-pressure coupled model of gas phase and liquid LPG under jet fire is established based on the equation of state, the VOF model and the RNG k-ɛ model. Then the super wavelet finite element formulation is constructed using the super wavelet scale function as interpolating function. Finally, the simulation is carried out, and results show that the super wavelet finite element method has higher computing precision than wavelet finite element method.

  14. Parametric analysis of fire model CFAST

    International Nuclear Information System (INIS)

    This paper describes the pump room fire of the nuclear power plant using CFAST fire modeling code developed by NIST. It is determined by the constrained or unconstrained fire, Lower Oxygen Limit (LOL), Radiative Fraction (RF), and the times to open doors, which are the input parameters of CAFST. According to the results, pump room fire is ventilation-controlled fire, so it is adequate that the value of LOL is 10% which is also the default value. It is appeared that the RF does not change the temperature of the upper gas layer. But the level of opening of the penetrating area and the times to opening it have an effect on the temperature of the upper layer, so it is determined that the results of it should be carefully analyzed

  15. Validation and uncertainty quantification of Fuego simulations of calorimeter heating in a wind-driven hydrocarbon pool fire.

    Energy Technology Data Exchange (ETDEWEB)

    Domino, Stefan Paul; Figueroa, Victor G.; Romero, Vicente Jose; Glaze, David Jason; Sherman, Martin P.; Luketa-Hanlin, Anay Josephine

    2009-12-01

    The objective of this work is to perform an uncertainty quantification (UQ) and model validation analysis of simulations of tests in the cross-wind test facility (XTF) at Sandia National Laboratories. In these tests, a calorimeter was subjected to a fire and the thermal response was measured via thermocouples. The UQ and validation analysis pertains to the experimental and predicted thermal response of the calorimeter. The calculations were performed using Sierra/Fuego/Syrinx/Calore, an Advanced Simulation and Computing (ASC) code capable of predicting object thermal response to a fire environment. Based on the validation results at eight diversely representative TC locations on the calorimeter the predicted calorimeter temperatures effectively bound the experimental temperatures. This post-validates Sandia's first integrated use of fire modeling with thermal response modeling and associated uncertainty estimates in an abnormal-thermal QMU analysis.

  16. Computer simulation of forest fire and its possible usage

    International Nuclear Information System (INIS)

    In this paper authors deal with computer modelling of forest fires. Their possible usage is discussed. Results of modelling are compared with real forest fire in the National Park Slovensky Raj (Slovak Paradise) in 2000 year

  17. FIRE-BGC--A Mechanistic Ecological Process Model for Simulating Fire Succession on Coniferous Forest Landscapes of the Northern Rocky Mountains

    OpenAIRE

    Keane, Robert E.; Morgan, Penelope; Running, Steven W.

    1996-01-01

    An ecological process model of vegetation dynamics mechanistically simulates long-term stand dynamics on coniferous landscapes of the Northern Rocky Mountains. This model is used to investigate and evaluate cumulative effects of various fire regimes, including prescribed burning and fire exclusion, on the vegetation and fuel complex of a simulation landscape composed of many stands. Detailed documentation of the model FIRE-BGC (a FIRE BioGeoChemical succession model) with complete discussion ...

  18. FIRE-BGC -- A Mechanistic Ecological Process Model for Simulating Fire Succession on Coniferous Forest Landscapes of the Northern Rocky Mountains

    OpenAIRE

    United States Department of Agriculture, Forest Service

    1996-01-01

    An ecological process model of vegetation dynamics mechanistically simulates long-term stand dynamics on coniferous landscapes of the Northern Rocky Mountains. This model is used to investigate and evaluate cumulative effects of various fire regimes, including prescribed burning and fire exclusion, on the vegetation and fuel complex of a simulation landscape composed of many stands. Detailed documentation of the model FIRE-BGC (a FIRE BioGeoChemical succession model) with complete discussio...

  19. WRF fire simulation coupled with a fuel moisture model and smoke transport by WRF-Chem

    CERN Document Server

    Kochanski, Adam K; Mandel, Jan; Kim, Minjeong

    2012-01-01

    We describe two recent additions to WRF coupled with a fire spread model. Fire propagation is strongly dependent on fuel moisture, which in turn depends on the history of the atmosphere. We have implemented a equilibrium time-lag model of fuel moisture driven by WRF variables. The code allows the user to specify fuel parameters, with the defaults calibrated to the Canadian fire danger rating system for 10-hour fuel. The moisture model can run coupled with the atmosphere-fire model, or offline from WRF output to equilibrate the moisture over a period of time and to provide initial moisture conditions for a coupled atmosphere-fire-moisture simulation. The fire model also inserts smoke tracers into WRF-Chem to model the transport of fire emissions. The coupled model is available from OpenWFM.org. An earlier version of the fire model coupled with atmosphere is a part of WRF release.

  20. Semi-automatic analysis of fire debris

    Science.gov (United States)

    Touron; Malaquin; Gardebas; Nicolai

    2000-05-01

    Automated analysis of fire residues involves a strategy which deals with the wide variety of received criminalistic samples. Because of unknown concentration of accelerant in a sample and the wide range of flammable products, full attention from the analyst is required. Primary detection with a photoionisator resolves the first problem, determining the right method to use: the less responsive classical head-space determination or absorption on active charcoal tube, a better fitted method more adapted to low concentrations can thus be chosen. The latter method is suitable for automatic thermal desorption (ATD400), to avoid any risk of cross contamination. A PONA column (50 mx0.2 mm i.d.) allows the separation of volatile hydrocarbons from C(1) to C(15) and the update of a database. A specific second column is used for heavy hydrocarbons. Heavy products (C(13) to C(40)) were extracted from residues using a very small amount of pentane, concentrated to 1 ml at 50 degrees C and then placed on an automatic carousel. Comparison of flammables with referenced chromatograms provided expected identification, possibly using mass spectrometry. This analytical strategy belongs to the IRCGN quality program, resulting in analysis of 1500 samples per year by two technicians. PMID:10802196

  1. Nonlinear phased analysis of reinforced concrete tunnels under fire exposure

    NARCIS (Netherlands)

    Lilliu, G.; Meda, A.

    2013-01-01

    Fire analysis of precast segmental tunnels involves several problems, mainly related to the soil-structure interaction during fire exposure, coupled with material degradation. Temperature increase in the tunnel is the cause of thermal expansion of the lining, which is resisted by the soil pressure.

  2. Material Analysis for a Fire Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Alexander; Nemer, Martin B.

    2014-08-01

    This report consolidates technical information on several materials and material classes for a fire assessment. The materials include three polymeric materials, wood, and hydraulic oil. The polymers are polystyrene, polyurethane, and melamine- formaldehyde foams. Samples of two of the specific materials were tested for their behavior in a fire - like environment. Test data and the methods used to test the materials are presented. Much of the remaining data are taken from a literature survey. This report serves as a reference source of properties necessary to predict the behavior of these materials in a fire.

  3. Fire Risk Analysis and Optimization of Fire Prevention Management for Green Building Design and High Rise Buildings: Hong Kong Experience

    Directory of Open Access Journals (Sweden)

    Yau Albert

    2014-12-01

    Full Text Available There are many iconic high rise buildings in Hong Kong, for example, International Commercial Centre, International Financial Centre, etc. Fire safety issue in high rise buildings has been raised by local fire professionals in terms of occupant evacuation, means of fire-fighting by fire fighters, sprinkler systems to automatically put off fires in buildings, etc. Fire risk becomes an important issue in building fire safety because it relates to life safety of building occupants where they live and work in high rise buildings in Hong Kong. The aim of this research is to identify the fire risk for different types of high rise buildings in Hong Kong and to optimise the fire prevention management for those high rise buildings with higher level of fire risk and to validate the model and also to carry out the study of the conflict between the current fire safety building code and the current trend of green building design. Survey via the 7-point scale questionnaire was conducted through 50 participants and their responses were received and analysed via the statistical tool SPSS software computer program. A number of statistical methods of testing for significantly difference in samples were adopted to carry out the analysis of the data received. When the statistical analysis was completed, the results of the data analysis were validated by two Fire Safety Experts in this area of specialisation and also by quantitative fire risk analysis.

  4. 324 Building fire hazards analysis implementation plan

    International Nuclear Information System (INIS)

    In March 1998, the 324 Building Fire Hazards Analysis (FHA) (Reference 1) was approved by the U S. Department of Energy, Richland Operations Office (DOE-RL) for implementation by B and W Hanford Company (BWHC). The purpose of the FHA was to identify gaps in compliance with DOE Order 5480.7A (Reference 2) and Richland Operations Office Implementation Directive (RLID) 5480.7 (Reference 3), especially in regard to loss limitation. The FHA identified compliance gaps in six areas and provided 20 recommendations to bring the 324 Building into compliance with DOE Order 5480 7A. Additionally, one observation was provided. A status is provided for each recommendation in this document. The actions for recommendations associated with the safety related part of the 324 Building and operation of the cells and support areas were evaluated using the Unreviewed Safety Question (USQ) process BWHC will use this Implementation Plan to bring the 324 Building and its operation into compliance with DOE Order 5480 7A and RLID 5480.7

  5. Fire risk analysis: a discussion on uncertainties and limitations

    International Nuclear Information System (INIS)

    A fire risk analysis, using probabilistic methods, attempts to model fire scenarios that can be described in terms of the following elements: ignition of fire, growth of the fire, detection and suppression processes, impact on cables and other equipment, and response of the automatic safety and control systems and plant operators. The level of uncertainties and limitations of the analysis varies among these elements. Although the potential failure modes of cables and electrical circuits have been debated for a long time, there are some uncertainties in our understanding of the failure modes of equipment under fire conditions. Smoke propagation and smoke damage have generally been omitted from fire risk studies. Shorts within electronic circuit boards caused by soot deposits are not modeled, such failures can have an impact on the information provided to the control room operator. The operators' response to the changes on the control board is certainly a complex issue. The behavior of control room operators when there is a fire in the control room is also the subject of much debate. Of specific concern is the proper transfer of the controls to the remote shutdown panel. Another area of much debate centers around the control of combustibles. Several studies have taken credit for the house-keeping procedures to screen potential fire scenarios in areas of a plant that contain a large collection of cables (e.g., a cable tunnel or cable shaft). In such cases, clearly the debate is over the likelihood of a fire that can cause damage. None of the fire risk analyses familiar to the authors have properly modeled the simultaneous effect of a fire on multi-units. (author)

  6. Improvement of fire protection measures for nuclear power plants

    International Nuclear Information System (INIS)

    Improvements of fire protection measures for nuclear power plants were performed as following items: Development of fire hazard analysis method. Application of developed Fire Dynamic Tool to actual plants (FDTS), With regard to fire tests for the fire data acquisition, cable fire test and High Energy Arcing Faults (HEAF) fire test were performed. Implementation of fire hazard analysis code and simulation were performed as following items: Fire analysis codes FDS, SYLVIA, and CFAST were implemented in order to analyze the fire progression phenomena. Trial simulation of HEAF accident of Onagawa NPP in Tohoku earthquake. (author)

  7. Dynamic Simulation of VEGA SRM Bench Firing By Using Propellant Complex Characterization

    Science.gov (United States)

    Di Trapani, C. D.; Mastrella, E.; Bartoccini, D.; Squeo, E. A.; Mastroddi, F.; Coppotelli, G.; Linari, M.

    2012-07-01

    During the VEGA launcher development, from the 2004 up to now, 8 firing tests have been performed at Salto di Quirra (Sardinia, Italy) and Kourou (Guyana, Fr) with the objective to characterize and qualify of the Zefiros and P80 Solid Rocket Motors (SRM). In fact the VEGA launcher configuration foreseen 3 solid stages based on P80, Z23 and Z9 Solid Rocket Motors respectively. One of the primary objectives of the firing test is to correctly characterize the dynamic response of the SRM in order to apply such a characterization to the predictions and simulations of the VEGA launch dynamic environment. Considering that the solid propellant is around 90% of the SRM mass, it is very important to dynamically characterize it, and to increase the confidence in the simulation of the dynamic levels transmitted to the LV upper part from the SRMs. The activity is articulated in three parts: • consolidation of an experimental method for the dynamic characterization of the complex dynamic elasticity modulus of elasticity of visco-elastic materials applicable to the SRM propellant operative conditions • introduction of the complex dynamic elasticity modulus in a numerical FEM benchmark based on MSC NASTRAN solver • analysis of the effect of the introduction of the complex dynamic elasticity modulus in the Zefiros FEM focusing on experimental firing test data reproduction with numerical approach.

  8. Miss Distance Analysis Method of Antiaircraft Gun Firing Test Based on Simulation Deduction%基于仿真推演的高炮射击脱靶量解算方法

    Institute of Scientific and Technical Information of China (English)

    杨琳; 孟宪国; 朱元昌; 邸彦强

    2013-01-01

    In order to solve the problem of feasibility demonstration for the shooting test scheme of antiaircraft gun weapon system,the new method of miss distance analysis during the deducing is carried on. In the course of deducing,the target flight path has been produced by using the interpolation method on the measurement data,and the trajectory orbit of the antiaircraft gun weapon system has been built according to the firing table. In the virtual digital environment of the shooting range,the key processes of the test have been emulated,such as the target flight,the tracing measurement of the equipments and the firing of the weapon system. This method has guaranteed the consistency between the simulation deduction data and the actual test condition of the shooting range,and it has improved the accuracy of miss distance analysis and the credibility of the test scheme demonstration.%针对靶场高炮武器系统射击精度试验的试验方案可行性论证问题进行研究,提出了一种在仿真推演过程中进行脱靶量解算的新方法,根据靶场已有测量数据插值生成飞行目标航迹,根据射表数据得到被试高炮武器系统的弹道轨迹,在虚拟数字靶场环境中通过时间管理策略实现了对试验过程中目标靶机的飞行、参试设备的跟踪测量、被试武器系统射击等的仿真,保证了仿真推演数据与靶场实际试验条件的一致性,提高了脱靶量解算的准确性和方案论证的可信性。

  9. Fire simulation for a 3D character with particles and motion capture data in Blender

    OpenAIRE

    Hoikkala, Ville

    2016-01-01

    The object of this thesis was to study particle based simulations in 3D and how they can be applied to motion capture data. The theoretical part examines the history of 3D and computer graphics concisely and finally particles and simulations. The practical part consists of the case-work involving a fire emitting particle simulation. The study examines two methods of creating a fire simulation in Blender and how they influence the outlook of the particles. It was found that the fire si...

  10. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    Directory of Open Access Journals (Sweden)

    Bjørn Qvale

    2003-06-01

    Full Text Available

    This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT by supplementary direct gas-firing. The supplementary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, supplementary firing is expected to result in a high marginal efficiency. The paper shows that depending on the application, this is not always the case.

    The interest in this cycle arises from a recent demonstration of the feasibility of a two-stage gasification process through construction of several plants. The gas from this process could be divided into two streams, one for primary and one for supplementary firing. A preliminary analysis of the ideal, recuperated Brayton cycle shows that for this cycle any supplementary firing will have a marginal efficiency of unity per extra unit of fuel. The same result is obtained for the indirectly fired gas turbine (IFGT and for the supplementary-fired IFGT. These results show that the combination of external firing and internal firing have the potential of reducing or solving some problems associated with the use of biomass both in the recuperated and the indirectly fired gas turbine: The former requires a clean, expensive fuel. The latter is limited in efficiency due to limitations in material temperature of the heat exchanger. Thus, in the case of an IBFGT, it would appear be very appropriate to use a cheap biomass or waste fuel for low temperature combustion and external firing and use natural gas at a high marginal efficiency for high temperature heating. However, it is shown that this is not the case for a simple IBFGT supplementary-fired with natural gas. The marginal efficiency of the natural gas is in this case found to be independent of temperature ratio and lower than for the recuperated gas turbine. Instead, other process changes may be considered in order to obtain a high marginal efficiency on natural gas. Two possibilities

  11. Simulation of Intelligent Fire Detection and Alarm System for a W d p .

    Directory of Open Access Journals (Sweden)

    V. B. Pati

    1989-01-01

    Full Text Available Fire is one of the major hazards in warships. A warship being avery complex structure, with sophisticated weapons, machinery, fueland ammunition is always at risk of fire. Restrictions on movement of ship's personnel and equipment requires automation in fire detectionand control systems. This paper describes the limitations of conventional fire detection systems, followed by the features of modern fire detection and alarnr (the so-called intelligent systems and thetypes of fire detectors used in fire detection systems. The experimentalset-up used for simulating a simple system having 24 sensors connecteato the micro computer via digital input card is explained in detail withthe limitations of the experimental set-up and improvements that canbe made by incorporating serial communication in a loop, using fibre optics data links. and intelligent loop/interface units.

  12. Clinimetric quality of the fire fighting simulation test as part of the Dutch fire fighters Workers' Health Surveillance

    Directory of Open Access Journals (Sweden)

    Sluiter Judith K

    2010-02-01

    Full Text Available Abstract Background Clinimetric data for the fire fighting simulation test (FFST, a new test proposed for the Workers' Health Surveillance (WHS of Dutch fire fighters, were evaluated. Methods Twenty-one fire fighters took the FFST three times with one and three weeks between testing. Clinimetric quality was determined by means of reliability, agreement and validity. For reliability and agreement, the intraclass correlation coefficient (ICC, and standard error of measurement (SEM, were analysed. For construct validity, the tests from 45 fire fighters were correlated with their own and their supervisors' rated work ability. Results The ICCs were 0.56 and 0.79 at the one-week and three-week test-retest periods, respectively. Testing times ranged from 9 to 17 minutes; the SEMs were 70 s at the one-week and 40 s at the three-week test-retest periods. The construct validity was moderate (-0.47 ≤ r ≤ -0.33; p Conclusions The FFST was reliable with acceptable agreement after three weeks. Construct validity was moderate. We recommend using FFST as a part of the WHS for Dutch fire fighters. It is advised that fire fighters should perform the FFST once as a trial before judging their performance in testing time during the second performance.

  13. Real time simulation of 2007 Santa Ana fires

    CERN Document Server

    Kochanski, A K; Krueger, S K; Mandel, J; Beezley, J D

    2012-01-01

    There are many wildfire behaviors of increasing relevance that are outside the forecast capabilities of even the most sophisticated operational fire spread and fire behavior model. The limitations of the operational models are due primarily to their inability to represent coupled fire-atmosphere interactions. Coupled wildfire-atmosphere models are physics-based fluid-dynamical prognostic models of wildfire spread and behavior that attempt an almost complete representation of fire-atmosphere interactions. This level of fidelity however means that these models cannot be used operationally. The reason is that, despite ever increasing computational resources, the complexity and range of processes and scales (1 mm to 100 km) involved in this modeling approach make computational costs prohibitively expensive. In this study we propose an intermediate approach. A physics-based coupled atmosphere-fire model is used to resolve the large-scale and local weather as well as the atmosphere-fire interactions, while combusti...

  14. Modeling and Analysis of Realistic Fire Scenarios in Spacecraft

    Science.gov (United States)

    Brooker, J. E.; Dietrich, D. L.; Gokoglu, S. A.; Urban, D. L.; Ruff, G. A.

    2015-01-01

    An accidental fire inside a spacecraft is an unlikely, but very real emergency situation that can easily have dire consequences. While much has been learned over the past 25+ years of dedicated research on flame behavior in microgravity, a quantitative understanding of the initiation, spread, detection and extinguishment of a realistic fire aboard a spacecraft is lacking. Virtually all combustion experiments in microgravity have been small-scale, by necessity (hardware limitations in ground-based facilities and safety concerns in space-based facilities). Large-scale, realistic fire experiments are unlikely for the foreseeable future (unlike in terrestrial situations). Therefore, NASA will have to rely on scale modeling, extrapolation of small-scale experiments and detailed numerical modeling to provide the data necessary for vehicle and safety system design. This paper presents the results of parallel efforts to better model the initiation, spread, detection and extinguishment of fires aboard spacecraft. The first is a detailed numerical model using the freely available Fire Dynamics Simulator (FDS). FDS is a CFD code that numerically solves a large eddy simulation form of the Navier-Stokes equations. FDS provides a detailed treatment of the smoke and energy transport from a fire. The simulations provide a wealth of information, but are computationally intensive and not suitable for parametric studies where the detailed treatment of the mass and energy transport are unnecessary. The second path extends a model previously documented at ICES meetings that attempted to predict maximum survivable fires aboard space-craft. This one-dimensional model implies the heat and mass transfer as well as toxic species production from a fire. These simplifications result in a code that is faster and more suitable for parametric studies (having already been used to help in the hatch design of the Multi-Purpose Crew Vehicle, MPCV).

  15. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2003-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supple-mentary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, sup-plementary firing is expected to...... former requires a clean, expensive fuel. The latter is limited in efficiency due to limita-tions in material temperature of the heat exchanger. Thus, in the case of an IBFGT, it would appear be very appropriate to use a cheap biomass or waste fuel for low tempera-ture combustion and external firing and...... the recu-perated gas turbine. Instead, other process changes may be considered in order to obtain a high marginal efficiency on natural gas. Two possibilities are discussed: Integration between an IFGT and pyrolysis of the biofuel which will result in a highly efficient utilization of the biomass, and...

  16. CFD simulation of coal and straw co-firing

    DEFF Research Database (Denmark)

    Junker, Helle; Hvid, Søren L.; Larsen, Ejvind;

    This paper presents the results of a major R&D program with the objective to develop CFD based tools to assess the impact of biomass co-firing in suspension fired pulverized coal power plants. The models have been developed through a series of Danish research projects with the overall objective...... emissions. Results are presented for a Danish full-scale boiler that is currently co-firing biomass with coal on a commercial basis....

  17. Fire analysis for compartment of ITER tritium SDS

    International Nuclear Information System (INIS)

    The objective of the fire accident analysis for the compartment where the ITER tritium storage and delivery system (hereafter SDS) glove boxes are installed is to estimate the integrity of the glove box. Fires in grouped electrical cable trays pose distinct fire hazards within the compartment where the SDS glove boxes are installed. The nuclear industry has defined two general types of electrical cables, referred to as IEEE 383 qualified and unqualified. According to NUREG/CR 4679 and DOT TSC UMAT 83 4 1, a damage threshold temperature of 370 .deg. C and a critical heat flux of 10 kW/m2 have been selected for IEEE 383 qualified cable. A damage threshold temperature of 218 .deg. C and a critical heat flux of 5 kW/m2 have been selected for IEEE 383 unqualified cable. Cable tray fires can occur from various sources. The scenarios of concern include a fire within a cable tray and as exposure fire. However, fire within the compartment where the SDS glove boxes are installed could be happened due to over currents. Therefore, it is common practice to consider only self ignited cable fires to occur in power cable trays since they carry enough electrical energy for ignition. In general, electrical cables typically do not carry enough electrical energy for self ignition. According to NUREG/CR 5384, it was concluded that electrical cables which passed the IEEE 383 74 flame test were less likely to propagate electrically initiated fires. However, the scenario in this fire accident analysis assumed that the IEEE 383 qualified cable is burned completely

  18. A sensitivity analysis for fire and ITER-FEAT performances

    International Nuclear Information System (INIS)

    A 0-D analysis of the performances of the FIRE and ITER-FEAT projects is presented. The two projects are compared with the same rules for the density and temperature profiles, impurity contents and τ*He/τE constraint, using three different scaling laws for the energy confinement time: IPB98(y), IPB98(y,1) and IPB98(y,2). With IPB98(y) scaling and FIRE rules for the profiles and impurity contents, the Q = 10 nominal operating point of the FIRE project is reproduced. With the same assumptions, the ITER-FEAT project is shown to operate at Q = 50. Using IPB98(y,1) scaling and FIRE rules for profiles and impurity contents, the maximum Q for FIRE is reduced to Q = 7.5 while an operating point at Q = 50 is still found for ITER-FEAT. Using IPB98(y,2) scaling and FIRE rules, the maximum Q for FIRE is reduced to Q = 4.3 while it is reduced to Q = 17 in ITER-FEAT. At last, using IPB98(y,2) scaling and ITER-FEAT rules for profiles and impurity contents, the nominal operating point at Q = 10 of ITER-FEAT is reproduced while the maximum Q in FIRE is reduced to Q = 2.8. (authors)

  19. Fire dynamics during the 20th century simulated by the Community Land Model

    Directory of Open Access Journals (Sweden)

    S. Kloster

    2010-01-01

    Full Text Available Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite based estimates in terms of magnitude, spatial extent as well as interannual and seasonal variability. Longterm trends during the 20th century were compared with historical estimates. Overall we found the best agreement between simulation and observations for the fire parametrization based on the work by Arora and Boer (2005. We obtain substantial improvement when we explicitly considered human caused ignition and fire suppression as a function of population density. Simulated fire carbon emissions ranged between 2.0 and 2.4 Pg C/year for the period 1997–2004. Regionally the simulations had a low bias over Africa and a high bias over South America when compared to satellite based products. The net terrestrial carbon source due to land use change for the 1990s was 1.2 Pg C/year with 11% stemming from deforestation fires. During 2000–2004 this flux decreased to 0.85 Pg C/year with a similar relative contribution from deforestation fires. Between 1900 and 1960 we simulated a slight downward trend in global fire emissions, which is explained by reduced fuels as a consequence of wood harvesting and partly by increasing fire suppression. The model predicted an upward trend in the last three decades of the 20th century caused by climate variations and large burning events associated with ENSO induced drought conditions.

  20. Impacts of tree canopy structure on wind flows and fire propagation simulated with FIRETEC

    OpenAIRE

    Pimont, François; Dupuy, Jean-Luc; Linn, Rodman R.; Dupont, Sylvain

    2011-01-01

    Forest fuel management in the context of fire prevention generally induces heterogeneous spatial patterns of vegetation. However, the impact of the canopy structure on both wind flows and fire behavior is not well understood. Here, a coupled atmosphere wildfire behavior model, HIGRAD/FIRETEC, was used to investigate the effects of canopy treatment on wind field and fire behavior in a typical Mediterranean pine ecosystem. First, the treatment-induced winds were simulated with the model. We obs...

  1. Gusty, gaseous flows of FIRE: galactic winds in cosmological simulations with explicit stellar feedback

    CERN Document Server

    Muratov, Alexander L; Faucher-Giguere, Claude-Andre; Hopkins, Philip F; Quataert, Eliot; Murray, Norman

    2015-01-01

    We present an analysis of the galaxy-scale gaseous outflows from the FIRE (Feedback in Realistic Environments) simulations. This suite of hydrodynamic cosmological zoom simulations provides a sample of halos where star-forming giant molecular clouds are resolved to z=0, and features an explicit stellar feedback model on small scales. In this work, we focus on quantifying the gas mass ejected out of galaxies in winds and how this material travels through the halo. We correlate these quantities to star formation in galaxies throughout cosmic history. Our simulations reveal that a significant portion of every galaxy's evolution, particularly at high redshift, is dominated by bursts of star formation, which are followed by powerful gusts of galactic outflow that sweep up a large fraction of gas in the interstellar medium and send it through the circumgalactic medium. The dynamical effect of these outflows can significantly limit the amount of star formation within the affected galaxy. At low redshift, however, su...

  2. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    Directory of Open Access Journals (Sweden)

    Marc A. Rosen

    2012-03-01

    Full Text Available The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel and two coals (bituminous coal and lignite are considered. Key system performance parameters are evaluated for various fuel combinations and co-firing ratios, using a system model and numerical simulation. The results indicate that plant energy efficiency decreases with increase of biomass proportion in the fuel mixture, and that the extent of the decrease depends on specific properties of the coal and biomass types.

  3. Risk management application of fire risk analysis

    International Nuclear Information System (INIS)

    Probabilistic risk assessment (PRA) has shown that the contribution of fires to the frequency of core damage and radionuclide release in some nuclear power plants can be significant. This article discusses the use of PRA results in fire risk management. The decomposition of these results leads to the identification of the most important contributors to the risk and, thus, allows for the identification of potential modifications that can have the greatest impact on risk. This paper discusses the process of generating these options and offers several insights that have been gained from an actual study. (author)

  4. Simulation of air quality impacts from prescribed fires on an urban area.

    Science.gov (United States)

    Hu, Yongtao; Odman, M Talat; Chang, Michael E; Jackson, William; Lee, Sangil; Edgerton, Eric S; Baumann, Karsten; Russell, Armistead G

    2008-05-15

    On February 28, 2007, a severe smoke event caused by prescribed forest fires occurred in Atlanta, GA. Later smoke events in the southeastern metropolitan areas of the United States caused by the Georgia-Florida wild forest fires further magnified the significance of forest fire emissions and the benefits of being able to accurately predict such occurrences. By using preburning information, we utilize an operational forecasting system to simulate the potential air quality impacts from two large February 28th fires. Our "forecast" predicts that the scheduled prescribed fires would have resulted in over 1 million Atlanta residents being potentially exposed to fine particle matter (PM2.5) levels of 35 microg m(-3) or higher from 4 p.m. to midnight. The simulated peak 1 h PM2.5 concentration is about 121 microg m(-3). Our study suggests that the current air quality forecasting technology can be a useful tool for helping the management of fire activities to protect public health. With postburning information, our "hindcast" predictions improved significantly on timing and location and slightly on peak values. "Hindcast" simulations also indicated that additional isoprenoid emissions from pine species temporarily triggered by the fire could induce rapid ozone and secondary organic aerosol formation during late winter. Results from this study suggest that fire induced biogenic volatile organic compounds emissions missing from current fire emissions estimate should be included in the future. PMID:18546707

  5. Fire hazard analysis for Plutonium Finishing Plant complex

    International Nuclear Information System (INIS)

    A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards

  6. Fire hazard analysis for Plutonium Finishing Plant complex

    Energy Technology Data Exchange (ETDEWEB)

    MCKINNIS, D.L.

    1999-02-23

    A fire hazards analysis (FHA) was performed for the Plutonium Finishing Plant (PFP) Complex at the Department of Energy (DOE) Hanford site. The scope of the FHA focuses on the nuclear facilities/structures in the Complex. The analysis was conducted in accordance with RLID 5480.7, [DOE Directive RLID 5480.7, 1/17/94] and DOE Order 5480.7A, ''Fire Protection'' [DOE Order 5480.7A, 2/17/93] and addresses each of the sixteen principle elements outlined in paragraph 9.a(3) of the Order. The elements are addressed in terms of the fire protection objectives stated in paragraph 4 of DOE 5480.7A. In addition, the FHA also complies with WHC-CM-4-41, Fire Protection Program Manual, Section 3.4 [1994] and WHC-SD-GN-FHA-30001, Rev. 0 [WHC, 1994]. Objectives of the FHA are to determine: (1) the fire hazards that expose the PFP facilities, or that are inherent in the building operations, (2) the adequacy of the fire safety features currently located in the PFP Complex, and (3) the degree of compliance of the facility with specific fire safety provisions in DOE orders, related engineering codes, and standards.

  7. Characteristic Analysis of Fire Modeling Codes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yoon Hwan; Yang, Joon Eon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Jong Hoon [Kyeongmin College, Ujeongbu (Korea, Republic of)

    2004-04-15

    This report documents and compares key features of four zone models: CFAST, COMPBRN IIIE, MAGIC and the Fire Induced Vulnerability Evaluation (FIVE) methodology. CFAST and MAGIC handle multi-compartment, multi-fire problems, using many equations; COMPBRN and FIVE handle single compartment, single fire source problems, using simpler equation. The increased rigor of the formulation of CFAST and MAGIC does not mean that these codes are more accurate in every domain; for instance, the FIVE methodology uses a single zone approximation with a plume/ceiling jet sublayer, while the other models use a two-zone treatment without a plume/ceiling jet sublayer. Comparisons with enclosure fire data indicate that inclusion of plume/ceiling jet sublayer temperatures is more conservative, and generally more accurate than neglecting them. Adding a plume/ceiling jet sublayer to the two-zone models should be relatively straightforward, but it has not been done yet for any of the two-zone models. Such an improvement is in progress for MAGIC.

  8. Fire dynamics during the 20th century simulated by the Community Land Model

    Energy Technology Data Exchange (ETDEWEB)

    Kloster, Silvia [Cornell University; Mahowald, Natalie [Cornell University; Randerson, Jim [University of California, Irvine; Thornton, Peter E [ORNL; Hoffman, Forrest M [ORNL; Levis, Sam [National Center for Atmospheric Research (NCAR); Lawrence, Peter J. [National Center for Atmospheric Research (NCAR); Feddema, Johan J. [University of Kansas; Oleson, Keith [National Center for Atmospheric Research (NCAR); Lawrence, David M. [National Center for Atmospheric Research (NCAR)

    2011-01-01

    Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite-based estimates in terms of magnitude and spatial extent as well as interannual and seasonal variability. Long-term trends during the 20th century were compared with historical estimates. Overall we found the best agreement between simulation and observations for the fire parametrization based on the work by Arora and Boer (2005). We obtained substantial improvement when we explicitly considered human caused ignition and fire suppression as a function of population density. Simulated fire carbon emissions ranged between 2.0 and 2.4 Pg C/year for the period 1997 2004. Regionally the simulations had a low bias over Africa and a high bias over South America when compared to satellite-based products. The net terrestrial carbon source due to land use change for the 1990s was 1.2 Pg C/year with 11% stemming from deforestation fires. During 2000 2004 this flux decreased to 0.85 Pg C/year with a similar relative contribution from deforestation fires. Between 1900 and 1960 we predicted a slight downward trend in global fire emissions caused by reduced fuels as a consequence of wood harvesting and also by increases in fire suppression. The model predicted an upward trend during the last three decades of the 20th century as a result of climate variations and large burning events associated with ENSO-induced drought conditions.

  9. Fire dynamics during the 20th century simulated by the Community Land Model

    Science.gov (United States)

    Kloster, S.; Mahowald, N. M.; Randerson, J. T.; Thornton, P. E.; Hoffman, F. M.; Levis, S.; Lawrence, P. J.; Feddema, J. J.; Oleson, K. W.; Lawrence, D. M.

    2010-06-01

    Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite-based estimates in terms of magnitude and spatial extent as well as interannual and seasonal variability. Long-term trends during the 20th century were compared with historical estimates. Overall we found the best agreement between simulation and observations for the fire parametrization based on the work by Arora and Boer (2005). We obtained substantial improvement when we explicitly considered human caused ignition and fire suppression as a function of population density. Simulated fire carbon emissions ranged between 2.0 and 2.4 Pg C/year for the period 1997-2004. Regionally the simulations had a low bias over Africa and a high bias over South America when compared to satellite-based products. The net terrestrial carbon source due to land use change for the 1990s was 1.2 Pg C/year with 11% stemming from deforestation fires. During 2000-2004 this flux decreased to 0.85 Pg C/year with a similar relative contribution from deforestation fires. Between 1900 and 1960 we predicted a slight downward trend in global fire emissions caused by reduced fuels as a consequence of wood harvesting and also by increases in fire suppression. The model predicted an upward trend during the last three decades of the 20th century as a result of climate variations and large burning events associated with ENSO-induced drought conditions.

  10. Fire dynamics during the 20th century simulated by the Community Land Model

    Directory of Open Access Journals (Sweden)

    S. Kloster

    2010-06-01

    Full Text Available Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite-based estimates in terms of magnitude and spatial extent as well as interannual and seasonal variability. Long-term trends during the 20th century were compared with historical estimates. Overall we found the best agreement between simulation and observations for the fire parametrization based on the work by Arora and Boer (2005. We obtained substantial improvement when we explicitly considered human caused ignition and fire suppression as a function of population density. Simulated fire carbon emissions ranged between 2.0 and 2.4 Pg C/year for the period 1997–2004. Regionally the simulations had a low bias over Africa and a high bias over South America when compared to satellite-based products. The net terrestrial carbon source due to land use change for the 1990s was 1.2 Pg C/year with 11% stemming from deforestation fires. During 2000–2004 this flux decreased to 0.85 Pg C/year with a similar relative contribution from deforestation fires. Between 1900 and 1960 we predicted a slight downward trend in global fire emissions caused by reduced fuels as a consequence of wood harvesting and also by increases in fire suppression. The model predicted an upward trend during the last three decades of the 20th century as a result of climate variations and large burning events associated with ENSO-induced drought conditions.

  11. Assessment of simulation predictions of hydrocarbon pool fire tests.

    Energy Technology Data Exchange (ETDEWEB)

    Luketa-Hanlin, Anay Josephine

    2010-04-01

    An uncertainty quantification (UQ) analysis is performed on the fuel regression rate model within SIERRA/Fuego by comparing to a series of hydrocarbon tests performed in the Thermal Test Complex. The fuels used for comparison for the fuel regression rate model include methanol, ethanol, JP8, and heptane. The recently implemented flamelet combustion model is also assessed with a limited comparison to data involving measurements of temperature and relative mole fractions within a 2-m diameter methanol pool fire. The comparison of the current fuel regression rate model to data without UQ indicates that the model over predicts the fuel regression rate by 65% for methanol, 63% for ethanol, 95% for JP8, and 15% for heptane. If a UQ analysis is performed incorporating a range of values for transmittance, reflectance, and heat flux at the surface the current model predicts fuel regression rates within 50% of measured values. An alternative model which uses specific heats at inlet and boiling temperatures respectively and does not approximate the sensible heat is also compared to data. The alternative model with UQ significantly improves the comparison to within 25% for all fuels except heptane. Even though the proposed alternative model provides better agreement to data, particularly for JP8 and ethanol (within 15%), there are still outstanding issues regarding significant uncertainties which include heat flux gauge measurement and placement, boiling at the fuel surface, large scale convective motion within the liquid, and semi-transparent behavior.

  12. Application of wildfire simulation methods to assess wildfire exposure in a Mediterranean fire-prone area (Sardinia, Italy)

    Science.gov (United States)

    Salis, M.; Ager, A.; Arca, B.; Finney, M.; Bacciu, V. M.; Spano, D.; Duce, P.

    2012-12-01

    Spatial and temporal patterns of fire spread and behavior are dependent on interactions among climate, topography, vegetation and fire suppression efforts (Pyne et al. 1996; Viegas 2006; Falk et al. 2007). Humans also play a key role in determining frequency and spatial distribution of ignitions (Bar Massada et al, 2011), and thus influence fire regimes as well. The growing incidence of catastrophic wildfires has led to substantial losses for important ecological and human values within many areas of the Mediterranean basin (Moreno et al. 1998; Mouillot et al. 2005; Viegas et al. 2006a; Riaño et al. 2007). The growing fire risk issue has led to many new programs and policies of fuel management and risk mitigation by environmental and fire agencies. However, risk-based methodologies to help identify areas characterized by high potential losses and prioritize fuel management have been lacking for the region. Formal risk assessment requires the joint consideration of likelihood, intensity, and susceptibility, the product of which estimates the chance of a specific loss (Brillinger 2003; Society of Risk Analysis, 2006). Quantifying fire risk therefore requires estimates of a) the probability of a specific location burning at a specific intensity and location, and b) the resulting change in financial or ecological value (Finney 2005; Scott 2006). When large fires are the primary cause of damage, the application of this risk formulation requires modeling fire spread to capture landscape properties that affect burn probability. Recently, the incorporation of large fire spread into risk assessment systems has become feasible with the development of high performance fire simulation systems (Finney et al. 2011) that permit the simulation of hundreds of thousands of fires to generate fine scale maps of burn probability, flame length, and fire size, while considering the combined effects of weather, fuels, and topography (Finney 2002; Andrews et al. 2007; Ager and Finney 2009

  13. SIMULATION OF FIRE DYNAMICS WITH VARIOUS GROWTH RATE IN PREMISES WITH NATURAL VENTILATION

    OpenAIRE

    V. V. Nevdakh

    2015-01-01

    Computer simulation of the initial fire stage dynamics with various growth rate have been carried out with the help of FDS software. In case of a quick fire 1055 kW heat liberation has been reached in accordance with quadratic law within 100 seconds, averagely within 250 seconds and within 500 seconds when the fire rate is slow. Source of fire has been located on the floor and at the height of 2 m. A doorway of 0.8×2.0 m size and two 0.8×0.1 m openings have been used as ventilation holes. One...

  14. A practical approach to fire hazard analysis for offshore structures

    International Nuclear Information System (INIS)

    Offshore quantitative risk assessments (QRA) have historically been complex and costly. For large offshore design projects, the level of detail required for a QRA is often not available until well into the detailed design phase of the project. In these cases, the QRA may be unable to provide timely hazard understanding. As a result, the risk reduction measures identified often come too late to allow for cost effective changes to be implemented. This forces project management to make a number of difficult or costly decisions. This paper demonstrates how a scenario-based approached to fire risk assessment can be effectively applied early in a project's development. The scenario or design basis fire approach calculates the consequence of a select number of credible fire scenarios, determines the potential impact on the platform process equipment, structural members, egress routes, safety systems, and determines the effectiveness of potential options for mitigation. The early provision of hazard data allows the project team to select an optimum design that is safe and will meet corporate or regulatory risk criteria later in the project cycle. The focus of this paper is on the application of the scenario-based approach to gas jet fires. This paper draws on recent experience in the Gulf of Mexico (GOM) and other areas to outline an approach to fire hazard analysis and fire hazard management for deep-water structures. The methods presented will include discussions from the recent June 2002 International Workshop for Fire Loading and Response

  15. Survey on the recent research trends for the fire events analysis

    International Nuclear Information System (INIS)

    This report aims at looking onto the recent research trends for the fire events analysis including PSA(Probabilsitc Safety Assessment) methodology. The objective of the internal fire events analysis is to estimate the contribution of the in-plant fires to overall plant core damage frequency and to identify the vulnerabilities to fire-induced events. Recently fire PSAs, have been performed for various types of reactors. The increasing capacity of PSA has enabled more detailed modeling for all aspects of the fire PSA including fire growth, suppression and the impact on systems. However, due to the lack of experimental data or validated models for key issues (e.g., fire growth, the impact of fire on equipment and operator performance), the results of current fire PSAs have significant uncertainties. Accordingly, the recent research trends for the fire events analysis in the report will be based on the fire PSA research to reduce the conversatism and the uncertainties in Korea

  16. PCDD/F and Aromatic Emissions from Simulated Forest and Grassland Fires

    Science.gov (United States)

    Emissions of polychlorinated dibenzodioxin and polychlorinated dibenzofuran (PCDD/F) from simulated grassland and forest fires were quantitatively sampled to derive emission factors in support of PCDD/F inventory development. Grasses from Kentucky and Minnesota; forest shrubs fro...

  17. Process simulation of co-firing torrefied biomass in a 220 MWe coal-fired power plant

    International Nuclear Information System (INIS)

    Highlights: • The performances of torrefaction based co-firing power plant are simulated by using Aspen Plus. • Mass loss properties and released gaseous components have been studied during biomass torrefaction processes. • Mole fractions of CO2 and CO account for 69–91% and 4–27% in total torrefied gases. • The electrical efficiency reduced when increasing either torrefaction temperature or substitution ratio of biomass. - Abstract: Torrefaction based co-firing in a pulverized coal boiler has been proposed for large percentage of biomass co-firing. A 220 MWe pulverized coal-power plant is simulated using Aspen Plus for full understanding the impacts of an additional torrefaction unit on the efficiency of the whole power plant, the studied process includes biomass drying, biomass torrefaction, mill systems, biomass/coal devolatilization and combustion, heat exchanges and power generation. Palm kernel shells (PKS) were torrefied at same residence time but 4 different temperatures, to prepare 4 torrefied biomasses with different degrees of torrefaction. During biomass torrefaction processes, the mass loss properties and released gaseous components have been studied. In addition, process simulations at varying torrefaction degrees and biomass co-firing ratios have been carried out to understand the properties of CO2 emission and electricity efficiency in the studied torrefaction based co-firing power plant. According to the experimental results, the mole fractions of CO2 and CO account for 69–91% and 4–27% in torrefied gases. The predicted results also showed that the electrical efficiency reduced when increasing either torrefaction temperature or substitution ratio of biomass. A deep torrefaction may not be recommended, because the power saved from biomass grinding is less than the heat consumed by the extra torrefaction process, depending on the heat sources

  18. Forecasting fire development with sensor-linked simulation

    OpenAIRE

    Koo, Sung-Han

    2010-01-01

    In fire, any information about the actual condition within the building could be essential for quick and safe response of both fire–fighters and occupants. In most cases, however, the emergency responders will rarely be aware of the actual conditions within a building and they will have to make critical decisions based on limited information. Recent buildings are equipped with numbers of sensors which may potentially contain useful information about the fire; however, most buil...

  19. Water Quality Analysis Simulation

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Water Quality analysis simulation Program, an enhancement of the original WASP. This model helps users interpret and predict water quality responses to natural...

  20. Need for a probabilistic fire analysis at nuclear power plants

    International Nuclear Information System (INIS)

    Although fire protection standards for nuclear power plants cover a wide scope and are constantly being updated, the existence of certain constraints makes it difficult to precisely evaluate plant response to different postulatable fires. These constraints involve limitations such as: - Physical obstacles which impede the implementation of standards in certain cases; - Absence of general standards which cover all the situations which could arise in practice; - Possible temporary noncompliance of safety measures owing to unforeseen circumstances; - The fact that a fire protection standard cannot possibly take into account additional damages occurring simultaneously with the fire; Based on the experience of the ASCO NPP PSA developed within the framework of the joint venture, INITEC-INYPSA-EMPRESARIOS AGRUPADOS, this paper seeks to justify the need for a probabilistic analysis to overcome the limitations detected in general application of prevailing standards. (author)

  1. Simulation on spread of fire smoke in the elevator shaft for a high-rise building

    OpenAIRE

    Yunchun Xia

    2014-01-01

    Spread of fire smoke in the elevator shaft of a high-rise building is influenced by many driving facts. We simulate smoke spreading in the elevator shaft, stair room, and pre-chamber with and without different supplied pressurized air. The simulation shows that smoke moves very fast in the elevator shaft. When a 12 floor high-rise building is in fire, smoke can fill up the elevator shaft in less than 1.5 min after a fire started, temperature in the elevator shaft can be higher than 187°C in 5...

  2. 一种细水雾灭火枪虚拟样机的建立及仿真分析%Establish and Simulation Analysis of the Virtual Prototype of Water Mist Fire-extinguishing Gun

    Institute of Scientific and Technical Information of China (English)

    韩星星; 韩纬华; 许历; 胡存; 苏先明

    2013-01-01

    The author has designed a brand new water mist fire-extinguishing gun.The essay has used SolidWorks software to create a virtual prototype of water mist fire-extinguishing gun,imported CAD model into the ANSYS environment for finite element analysis through the data interface of SolidWorks and ANSYS.%设计了一种全新的细水雾灭火枪,应用SolidWorks软件建立细水雾灭火枪的虚拟样机,通过SolidWorks和ANSYS的数据接口,将建好的CAD模型导入ANSYS环境中进行有限元分析.

  3. A comparative numerical study of turbulence models for the simulation of fire incidents: Application in ventilated tunnel fires

    Directory of Open Access Journals (Sweden)

    Konstantinos G. Stokos

    2015-12-01

    Full Text Available The objective of this paper is to compare the overall performance of two turbulence models used for the simulation of fire scenarios in ventilated tunnels. Two Reynolds Averaged Navier–Stokes turbulence models were used; the low-Re k–ω SST and the standard k–ε model with wall functions treatment. Comparison was conducted on two different fire scenarios. The varied parameters were the heat release rate and the ventilation rate. Results predicted by the two turbulence models were also compared to the results produced from the commercial package Ansys Fluent. Quite faster simulations were performed using the k–ε turbulence model with wall functions and our findings, as to the basic characteristics of smoke movement, were in good agreement with Ansys Fluent ones.

  4. Thermodynamic analysis of a new conception of supplementary firing in a combined cycle

    Science.gov (United States)

    Kotowicz, Janusz; Bartela, Łukasz; Balicki, Adrian

    2010-10-01

    The paper analyzes a new concept of integration of combined cycle with the installation of supplementary firing. The whole system was enclosed by thermodynamic analysis, which consists of a gas-steam unit with triple-pressure heat recovery steam generator. The system uses a determined model of the gas turbine and the assumptions relating to the construction features of steam-water part were made. The proposed conception involves building of supplementary firing installation only on part of the exhaust stream leaving the gas turbine. In the proposed solution superheater was divided into two sections, one of which was located on the exhaust gases leaving the installation of supplementary firing. The paper presents the results of the analyses of which the main aim was to demonstrate the superiority of the new thermodynamic concept of the supplementary firing over the classical one. For this purpose a model of a system was built, in which it was possible to carry out simulations of the gradual transition from a classically understood supplementary firing to the supplementary firing completely modified. For building of a model the GateCycle™ software was used.

  5. Simulating the effects of fire disturbance and vegetation recovery on boreal ecosystem carbon fluxes

    Science.gov (United States)

    Yi, Y.; Kimball, J. S.; Jones, L. A.; Zhao, M.

    2011-12-01

    Fire related disturbance and subsequent vegetation recovery has a major influence on carbon storage and land-atmosphere CO2 fluxes in boreal ecosystems. We applied a synthetic approach combining tower eddy covariance flux measurements, satellite remote sensing and model reanalysis surface meteorology within a terrestrial carbon model framework to estimate fire disturbance and recovery effects on boreal ecosystem carbon fluxes including gross primary production (GPP), ecosystem respiration and net CO2 exchange (NEE). A disturbance index based on MODIS land surface temperature and NDVI was found to coincide with vegetation recovery status inferred from tower chronosequence sites. An empirical algorithm was developed to track ecosystem recovery status based on the disturbance index and used to nudge modeled net primary production (NPP) and surface soil organic carbon stocks from baseline steady-state conditions. The simulations were conducted using a satellite based terrestrial carbon flux model driven by MODIS NDVI and MERRA reanalysis daily surface meteorology inputs. The MODIS (MCD45) burned area product was then applied for mapping recent (post 2000) regional disturbance history, and used with the disturbance index to define vegetation disturbance and recovery status. The model was then applied to estimate regional patterns and temporal changes in terrestrial carbon fluxes across the entire northern boreal forest and tundra domain. A sensitivity analysis was conducted to assess the relative importance of fire disturbance and recovery on regional carbon fluxes relative to assumed steady-state conditions. The explicit representation of disturbance and recovery effects produces more accurate NEE predictions than the baseline steady-state simulations and reduces uncertainty regarding the purported missing carbon sink in the high latitudes.

  6. Experimental study and advanced CFD simulation of fire safety performance of building external wall insulation system

    Directory of Open Access Journals (Sweden)

    Yan Zhenghua

    2013-11-01

    Full Text Available Large scale fire tests of building external wall insulation system were conducted. In the experiment, thermal-couples were mounted to measure the insulation system surface temperature and the gas temperature inside rooms at the second and third floors. Photos were also taken during the fire tests. The measurement provides information of the ignition and fire spread of the external insulation system which consists of surface protection layer, glass fibre net, bonding thin layer, anchor and the load bearing wall. Comprehensive simulations of the fire tests were carried out using an advanced CFD fire simulation software Simtec (Simulation of Thermal Engineering Complex [1, 2], which is now released by Simtec Soft Sweden, with the turbulent flow, turbulent combustion, thermal radiation, soot formation, convective heat transfer, the fully coupled three dimensional heat transfer inside solid materials, the ‘burn-out' of the surface protection layer and the pyrolysis of the insulation layer, etc, all computed. The simulation is compared with experimental measurement for validation. The simulation well captured the burning and fire spread of the external insulation wall.

  7. Potential Improvements in Human Reliability Analysis for Fire Risk Assessments

    International Nuclear Information System (INIS)

    The results of numerous fire risk assessments (FRA) and the experience gained from actual fire events have shown that fire can be a significant contributor to nuclear power plant (NPP) risk. However, on the basis of reviews of the FRAs performed for the Individual Plant External Events Examination (IPEEE) program in the U.S. and on recent research performed by U.S. Nuclear Regulatory Commission (NRC) to support increased use of risk information in regulatory decision making [e.g., Ref. 1, 2], it has become clear that improved modelling and quantification of human performance during fire events requires a better treatment of the special environment and response context produced by fires. This paper describes fire-related factors that have been identified as potentially impacting human performance, discusses to what extent such factors were modelled in the IPEEE FRAs, discusses prioritization of the factors likely to be most important to a realistic assessment of plant safety, and discusses which factors are likely to need additional research and development in order to allow adequate modelling in the human reliability analysis (HRA) portions of FRAs. The determination of which factors need to be modelled and the improvement of HRA related approaches for modelling such factors are critical aspects of the NRC's plan to improve FRA methods, tools, and data and to update a number of existing FRAs. (authors)

  8. Explosion and fire analysis of the Dora gas storage tanks

    International Nuclear Information System (INIS)

    Full text.The location of the Dora natural gas storage tanks within a close proximity to densely populated areas necessitates a thorough study of the risk associated with accidental gas releases and potential subsequent explosions. This paper describes the type and mechanism of release, the explosion form, the ensuing severity and the areas that are correspondingly affected. A variety of leakage scenarios are explored using mathematical models that simulate gas discharge, liquid leaks and two-phase gaseous and liquid streams. Relevant explosion models are discussed covering confined explosions, unconfined vapor cloud explosions, boiling liquid expanding vapor explosions and pool fires including the identification of the elements necessary for fire initiation. Fire explosion damages and influencing factors are then presented with the purpose of effecting a thorough reflection on damage extent. Finally, hazard control programs are defined on the basis of hazard priorities among the likely scenarios

  9. Development of PIRT and assessment matrix for verification and validation of sodium fire analysis codes

    International Nuclear Information System (INIS)

    Thermodynamic consequence in liquid sodium leak and fire accident is one of the important issues to be evaluated when considering the safety aspect of fast reactor plant building. The authors are therefore initiating systematic verification and validation (V and V) activity to assure and demonstrate the reliability of numerical simulation tool for sodium fire analysis. The V and V activity is in progress with the main focuses on already developed sodium fire analysis codes SPHINCS and AQUA-SF. The events to be evaluated are hypothetical sodium spray, pool, or combined fire accidents followed by thermodynamic behaviors postulated in a plant building. The present paper describes that the 'Phenomena Identification and Ranking Table (PIRT)' is developed at first for clarifying the important validation points in the sodium fire analysis codes, and that an 'Assessment Matrix' is proposed which summarizes both separate effect tests and integral effect tests for validating the computational models or whole code for important phenomena. Furthermore, the paper shows a practical validation with a separate effect test in which the spray droplet combustion model of SPHINCS and AQUA-SF predicts the burned amount of a falling sodium droplet with the error mostly less than 30%. (author)

  10. Forest Fires and Post - Fire Regeneration in Algeria Analysis with Satellite Data

    Science.gov (United States)

    Zegrar, Ahmed

    2016-07-01

    The Algerian forests are characterized by a particularly flammable material and fuel. The wind, the relief and the slope facilitates the propagation of fire. The use of remote sensing data multi-­dates, combined with other types of data of various kinds on the environment and forest burned, opens up interesting perspectives for the management of post-­fire regeneration. In this study the use of multi-­temporal remote sensing image Alsat-­1 and Landsat combined with other types of data concerning both background and burned down forest appears to be promising in evaluating and spatial and temporal effects of post fire regeneration. A spatial analysis taking into consideration the characteristics of the burned down site in the North West of Algeria, allowed to better account new factors to explain the regeneration and its temporal and spatial variation. We intended to show the potential use of remote sensing data from satellite ALSAT-­1, of spatial resolution of 32 m. . This approach allows showing the contribution of the data of Algerian satellite ALSAT in the detection and the well attended some forest fires in Algeria.

  11. Post Fire Safe Shutdown Analysis Using a Fault Tree Logic Model

    International Nuclear Information System (INIS)

    Every nuclear power plant should have its own fire hazard analysis including the fire safe shutdown analysis. A safe shutdown (SSD) analysis is performed to demonstrate the capability of the plant to safely shut down for a fire in any given area. The basic assumption is that there will be fire damage to all cables and equipment located within a common fire area. When evaluating the SSD capabilities of the plant, based on a review of the systems, equipment and cables within each fire area, it should be determined which shutdown paths are either unaffected or least impacted by a postulated fire within the fire area. Instead of seeking a success path for safe shutdown given all cables and equipment damaged by a fire, there can be an alternative approach to determine the SSD capability: fault tree analysis. This paper introduces the methodology for fire SSD analysis using a fault tree logic model

  12. Simulating fire regimes in the Amazon in response to climate change and deforestation.

    Science.gov (United States)

    Silvestrini, Rafaella Almeida; Soares-Filho, Britaldo Silveira; Nepstad, Daniel; Coe, Michael; Rodrigues, Hermann; Assunção, Renato

    2011-07-01

    Fires in tropical forests release globally significant amounts of carbon to the atmosphere and may increase in importance as a result of climate change. Despite the striking impacts of fire on tropical ecosystems, the paucity of robust spatial models of forest fire still hampers our ability to simulate tropical forest fire regimes today and in the future. Here we present a probabilistic model of human-induced fire occurrence for the Amazon that integrates the effects of a series of anthropogenic factors with climatic conditions described by vapor pressure deficit. The model was calibrated using NOAA-12 night satellite hot pixels for 2003 and validated for the years 2002, 2004, and 2005. Assessment of the fire risk map yielded fitness values > 85% for all months from 2002 to 2005. Simulated fires exhibited high overlap with NOAA-12 hot pixels regarding both spatial and temporal distributions, showing a spatial fit of 50% within a radius of 11 km and a maximum yearly frequency deviation of 15%. We applied this model to simulate fire regimes in the Amazon until 2050 using IPCC's A2 scenario climate data from the Hadley Centre model and a business-as-usual (BAU) scenario of deforestation and road expansion from SimAmazonia. Results show that the combination of these scenarios may double forest fire occurrence outside protected areas (PAs) in years of extreme drought, expanding the risk of fire even to the northwestern Amazon by midcentury. In particular, forest fires may increase substantially across southern and southwestern Amazon, especially along the highways slated for paving and in agricultural zones. Committed emissions from Amazon forest fires and deforestation under a scenario of global warming and uncurbed deforestation may amount to 21 +/- 4 Pg of carbon by 2050. BAU deforestation may increase fires occurrence outside PAs by 19% over the next four decades, while climate change alone may account for a 12% increase. In turn, the combination of climate change

  13. Global fire activity patterns (1996─2006 and climatic influence: an analysis using the World Fire Atlas

    Directory of Open Access Journals (Sweden)

    D. Oom

    2008-04-01

    Full Text Available Vegetation fires have been acknowledged as an environmental process of global scale, which affects the chemical composition of the troposphere, and has profound ecological and climatic impacts. However, considerable uncertainty remains, especially concerning intra and inter-annual variability of fire incidence. The main goals of our global-scale study were to characterise spatial-temporal patterns of fire activity, to identify broad geographical areas with similar vegetation fire dynamics, and to analyse the relationship between fire activity and the El Niño-Southern Oscillation. This study relies on 10 years (mid 1996–mid 2006 of screened European Space Agency World Fire Atlas (WFA data, obtained from Along Track Scanning Radiometer (ATSR and Advanced ATSR (AATSR imagery. Empirical Orthogonal Function analysis was used to reduce the dimensionality of the dataset. Regions of homogeneous fire dynamics were identified with cluster analysis, and interpreted based on their eco-climatic characteristics. The impact of 1997–1998 El Niño is clearly dominant over the study period, causing increased fire activity in a variety of regions and ecosystems, with variable timing. Overall, this study provides the first global decadal assessment of spatial-temporal fire variability and confirms the usefulness of the screened WFA for global fire ecoclimatology research.

  14. Coupled Atmosphere-Fire Simulations of Fireflux: Impacts of Model Resolution on Model Performance

    CERN Document Server

    Kochanski, Adam K; Jenkins, M A; Mandel, J; Beezley, J D

    2011-01-01

    The ability to forecast grass fire spread could be of a great importance for agencies making decisions about prescribed burns. However, the usefulness of the models used for fire-spread predictions is limited by the time required for completing the coupled atmosphere-fire simulations. In this study we analyze the sensitivity of a coupled model with respect to the vertical resolution of the atmospheric grid and the resolution of fire mesh that both affect computational performance of the model. Based on the observations of the plume properties recorded during the FireFlux experiment (Clements et al., 2007), we try to establish the optimal model configuration that provides realistic results for the least computational expense.

  15. Numerical simulation of sodium pool fires in liquid metal-cooled fast breeder reactor

    International Nuclear Information System (INIS)

    In Liquid Metal-Cooled Fast Breeder Reactor (LMFBR), the leakage of sodium can result in sodium fires. Due to sodium's high chemical reactivity in contact with air and water, sodium fires will lead to an immediate increase of the air temperature and pressure in the containment. This will harm the integrity of the containment. In order to estimate and foresee the sequence of this accident, or to prevent the accident and alleviate the influence of the accident, it is necessary to develop programs to analyze such sodium fire accidents. Based on the work of predecessors, flame sheet model is produced and used to analyze sodium pool fire accidents. Combustion model and heat transfer model are included and expatiated. And the comparison between the analytical and experimental results shows the program is creditable and reasonable. This program is more realistic to simulate the sodium pool fire accidents and can be used for nuclear safety judgement. (authors)

  16. Fire Airborne Simulator Arrangement: in progress status report

    OpenAIRE

    Di Stefano, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Buongiorno, M. F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Amici, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Romeo, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Badiali, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Mari, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione AC, Roma, Italia; Pippi, I.; IFAC-CNR, Firenze, Italia; Marcoionni, P.; IFAC-CNR, Firenze, Italia; Cherubini, G.; Galileo Avionica, Campi Bisenzio Italia; Lindermeier, E.; DLR, Germany

    2004-01-01

    The FASA project in collaboration with the DLR and the financing of ASI was started in order to combine bi-spectral imager and high-resolution FTIR- spectrometer (MIROR) for airborne remote sensing and gas analyis of high temperature events such as volcanoes and wild fires.

  17. Oblique electron fire hose instability: Particle-in-cell simulations

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, Pavel M.; Decyk, V.; Schriver, D.

    2014-01-01

    Roč. 119, č. 1 (2014), s. 59-68. ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041 Institutional support: RVO:67985815 Keywords : electron temperature anisotropy * fire hose instability Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.440, year: 2013

  18. Framework for real-time forest fire animation: Simulating fire spread using the GPU

    OpenAIRE

    Kjærnet, Øystein

    2010-01-01

    In 2009 Odd Erik Gundersen and Jo Skjermo described a conceptual framework for animating physically based forest fires. This project expands on their ideas with a focus on how modern graphics hardware can be utilized to achieve real-time performance. A prototype demonstrating some of the concepts suggested for the framework have been implemented and tested, successfully achieving real-time frame rates on a simple animation of a burning tree.

  19. Numerical simulations examining the possible role of anthropogenic and volcanic emissions during the 1997 Indonesian fires.

    Science.gov (United States)

    Pfeffer, Melissa Anne; Langmann, Bärbel; Heil, Angelika; Graf, Hans-F

    2012-09-01

    The regional atmospheric chemistry and climate model REMOTE has been used to conduct numerical simulations of the atmosphere during the catastrophic Indonesian fires of 1997. These simulations represent one possible scenario of the event, utilizing the RETRO wildland fire emission database. Emissions from the fires dominate the atmospheric concentrations of O(3), CO, NO(2), and SO(2) creating many possible exceedances of the Indonesian air quality standards. The scenario described here suggests that urban anthropogenic emissions contributed to the poor air quality due primarily to the fires. The urban air pollution may have increased the total number of people exposed to exceedances of the O(3) 1-h standard by 17%. Secondary O(3) from anthropogenic emissions enhanced the conversion of SO(2) released by the fires to [Formula: see text], demonstrating that the urban pollution actively altered the atmospheric behavior and lifetime of the fire emissions. Under the conditions present during the fires, volcanic SO(2) emissions had a negligible influence on surface pollution. PMID:22942920

  20. DAYCENT Simulations to Test the Influence of Fire Regime and Fire Suppression on Trace Gas Fluxes and Nitrogen Biogeochemistry of Colorado Forests

    Directory of Open Access Journals (Sweden)

    Mark A. Gathany

    2012-07-01

    Full Text Available Biological activity and the physical environment regulate greenhouse gas fluxes (CH4, N2O and NO from upland soils. Wildfires are known to alter these factors such that we collected daily weather records, fire return intervals, or specific fire years, and soil data of four specific sites along the Colorado Front Range. These data were used as primary inputs into DAYCENT. In this paper we test the ability of DAYCENT to simulate four forested sites in this area and to address two objectives: (1 to evaluate the short-term influence of fire on trace gas fluxes from burned landscapes; and (2 to compare trace gas fluxes among locations and between pre-/post- fire suppression. The model simulations indicate that CH4 oxidation is relatively unaffected by wildfire. In contrast, gross nitrification rates were reduced by 13.5–37.1% during the fire suppression period. At two of the sites, we calculated increases in gross nitrification rates (>100%, and N2O and NO fluxes during the year of fire relative to the year before a fire. Simulated fire suppression exhibited decreased gross nitrification rates presumably as nitrogen is immobilized. This finding concurs with other studies that highlight the importance of forest fires to maintain soil nitrogen availability.

  1. Determination of Ignitable Liquids in Fire Debris: Direct Analysis by Electronic Nose

    Directory of Open Access Journals (Sweden)

    Marta Ferreiro-González

    2016-05-01

    Full Text Available Arsonists usually use an accelerant in order to start or accelerate a fire. The most widely used analytical method to determine the presence of such accelerants consists of a pre-concentration step of the ignitable liquid residues followed by chromatographic analysis. A rapid analytical method based on headspace-mass spectrometry electronic nose (E-Nose has been developed for the analysis of Ignitable Liquid Residues (ILRs. The working conditions for the E-Nose analytical procedure were optimized by studying different fire debris samples. The optimized experimental variables were related to headspace generation, specifically, incubation temperature and incubation time. The optimal conditions were 115 °C and 10 min for these two parameters. Chemometric tools such as hierarchical cluster analysis (HCA and linear discriminant analysis (LDA were applied to the MS data (45–200 m/z to establish the most suitable spectroscopic signals for the discrimination of several ignitable liquids. The optimized method was applied to a set of fire debris samples. In order to simulate post-burn samples several ignitable liquids (gasoline, diesel, citronella, kerosene, paraffin were used to ignite different substrates (wood, cotton, cork, paper and paperboard. A full discrimination was obtained on using discriminant analysis. This method reported here can be considered as a green technique for fire debris analyses.

  2. Determination of Ignitable Liquids in Fire Debris: Direct Analysis by Electronic Nose

    Science.gov (United States)

    Ferreiro-González, Marta; Barbero, Gerardo F.; Palma, Miguel; Ayuso, Jesús; Álvarez, José A.; Barroso, Carmelo G.

    2016-01-01

    Arsonists usually use an accelerant in order to start or accelerate a fire. The most widely used analytical method to determine the presence of such accelerants consists of a pre-concentration step of the ignitable liquid residues followed by chromatographic analysis. A rapid analytical method based on headspace-mass spectrometry electronic nose (E-Nose) has been developed for the analysis of Ignitable Liquid Residues (ILRs). The working conditions for the E-Nose analytical procedure were optimized by studying different fire debris samples. The optimized experimental variables were related to headspace generation, specifically, incubation temperature and incubation time. The optimal conditions were 115 °C and 10 min for these two parameters. Chemometric tools such as hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA) were applied to the MS data (45–200 m/z) to establish the most suitable spectroscopic signals for the discrimination of several ignitable liquids. The optimized method was applied to a set of fire debris samples. In order to simulate post-burn samples several ignitable liquids (gasoline, diesel, citronella, kerosene, paraffin) were used to ignite different substrates (wood, cotton, cork, paper and paperboard). A full discrimination was obtained on using discriminant analysis. This method reported here can be considered as a green technique for fire debris analyses. PMID:27187407

  3. The role of historical fire disturbance in the carbon dynamics of the pan-boreal region: A process-based analysis

    Science.gov (United States)

    Balshi, M. S.; McGuire, A.D.; Zhuang, Q.; Melillo, J.; Kicklighter, D.W.; Kasischke, E.; Wirth, C.; Flannigan, M.; Harden, J.; Clein, J.S.; Burnside, T.J.; McAllister, J.; Kurz, W.A.; Apps, M.; Shvidenko, A.

    2007-01-01

    Wildfire is a common occurrence in ecosystems of northern high latitudes, and changes in the fire regime of this region have consequences for carbon feedbacks to the climate system. To improve our understanding of how wildfire influences carbon dynamics of this region, we used the process-based Terrestrial Ecosystem Model to simulate fire emissions and changes in carbon storage north of 45??N from the start of spatially explicit historically recorded fire records in the twentieth century through 2002, and evaluated the role of fire in the carbon dynamics of the region within the context of ecosystem responses to changes in atmospheric CO2 concentration and climate. Our analysis indicates that fire plays an important role in interannual and decadal scale variation of source/sink relationships of northern terrestrial ecosystems and also suggests that atmospheric CO2 may be important to consider in addition to changes in climate and fire disturbance. There are substantial uncertainties in the effects of fire on carbon storage in our simulations. These uncertainties are associated with sparse fire data for northern Eurasia, uncertainty in estimating carbon consumption, and difficulty in verifying assumptions about the representation of fires that occurred prior to the start of the historical fire record. To improve the ability to better predict how fire will influence carbon storage of this region in the future, new analyses of the retrospective role of fire in the carbon dynamics of northern high latitudes should address these uncertainties. Copyright 2007 by the American Geophysical Union.

  4. Oblique electron fire hose instability: Particle-in-cell simulations

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Trávníček, Pavel M.; Decyk, V.; Schriver, D.

    2014-01-01

    Roč. 119, č. 1 (2014), s. 59-68. ISSN 2169-9380 R&D Projects: GA ČR GAP209/12/2041 Grant ostatní: European Commission(XE) 284515 Institutional support: RVO:68378289 Keywords : electron temperature anisotropy * fire hose instability Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/2013JA019227/abstract

  5. Formal Probabilistic Analysis of a Wireless Sensor Network for Forest Fire Detection

    OpenAIRE

    Sofiène Tahar; Osman Hasan; Maissa Elleuch; Mohamed Abid

    2013-01-01

    Wireless Sensor Networks (WSNs) have been widely explored for forest fire detection, which is considered a fatal threat throughout the world. Energy conservation of sensor nodes is one of the biggest challenges in this context and random scheduling is frequently applied to overcome that. The performance analysis of these random scheduling approaches is traditionally done by paper-and-pencil proof methods or simulation. These traditional techniques cannot ascertain 100% accuracy, and thus are ...

  6. A fire hazard analysis at the Ignalina nuclear power plant

    International Nuclear Information System (INIS)

    The fire hazard analysis (FHA) of the Ignalina Nuclear Power Plant (INPP) Unit no.1 was initiated during 1997 and is estimated to finalise in summer 1998. The reason for starting a FHA was a recommendation in the Safety Analysis Report and its review to prioritise a systematic FHA. Fire protection improvements had earlier been based on engineering assessments, but further improvements required a systematic FHA. It is also required by the regulator for licensing of unit no.1. In preparation of the analysis it was decided to perform a deterministic FHA to fulfil the requirements in the IAEA draft of a Safety Practice ''Preparation of Fire Hazard Analyses for Nuclear Power Plants''. As a supporting document the United States Department of Energy Reactor Core Protection Evaluation Methodology for Fires at RBMK and WWER Nuclear Power Plants (RCPEM) was agreed to be used. The assistance of the project is performed as a bilateral activity between Sweden and UK. The project management is the responsibility of the INPP. In order to transfer knowledge to the INPP project group, training activities are arranged by the western team. The project will be documented as a safety case. The project consists of parties from INPP, Sweden, UK and Russia which makes the project very dependent of good communication procedures. The most difficult problems is except from the problems with translation, the problems with different standards and lack of testing protocols of the fire protection installations and problems to set the right level of screening criteria. There is also the new dimension of making it possible to take credit for the fire brigade in the safety case, which can bring the project into difficulties. The most interesting challenges for the project are to set the most sensible safety levels in the screening phase, to handle the huge volume of rooms for survey and screening, to maintain the good exchange of fire- and nuclear safety information between all the parties involved

  7. Experimental study and numerical simulation of spread law for fire on tunnel

    Institute of Scientific and Technical Information of China (English)

    牛会永; 乔晨露; 安敬鱼; 邓军

    2015-01-01

    In order to research spread law and distribution law of temperature nearby fire sources on roadway in mine, according to combustion theory and other basic, the theory model of temperature attenuation was determined under unsteady heat-exchange between wind and roadway wall. The full-size roadway fire simulation experiments were carried out in Chongqing Research Institute of China Coal Technology & Engineering Group Corporation. The development processes of mine fire and flow pattern of high temperature gas were analyzed. Experimental roadway is seen as physical model, and through using CFD software, the processes of mine fire have been simulated on computer. The results show that, after fire occurs, if the wind speed is less than the minimum speed which can prevent smoke from rolling back, then the smaller wind speed can cause smoke to roll back easily. Hot plume will lead to secondary disasters in upwind side. Because of roadway wall, hot plume released from roadway fire zone has caused the occurrence of the ceiling jet, and the hot plume has been forced down. Whereas, owing to the higher temperature, buoyancy effect is more obvious. Therefore, smoke rises gradually along the roadway in the flow process, and the hierarchical interface appears wavy. Oxygen-enriched combustion and fuel-enriched combustion are the two kinds of combustion states of fire. The oxygen content of downwind side of fire is maintained at around 15% for oxygen-enriched combustion, and the oxygen content of downwind side of fire is maintained at around 2% for fuel-enriched combustion. Furthermore, fuel-enriched combustion can lead to secondary disasters easily.

  8. Simulation of Forest Fire Spreading Based on Geographic Cellular Automata%林火蔓延地理元胞自动机仿真模拟

    Institute of Scientific and Technical Information of China (English)

    湛玉剑; 张帅; 张磊; 刘学军

    2013-01-01

    On the basis of geographical cellular automata, a forest fire spread simulation model which applied in the complex diversity of tree species is proposed for the complexity of the impact of forest fire spread factors in this paper. Meanwhile ,GIS technology, which is convenient to CA forest fire spread model for its ability to handle and analysis raster data and other abilities, is used to design and achieve a dynamic simulation of the spread model in this paper. Simulation results show that the model can simulate forest fire spread of different environments, and is suitable for simulation analyzing forest fire spread under the combined effects of various factors ,and also can provide technical support for prediction analysis of fire spread,estimating fire shape,burned area and the rate of spread and optimizing fire suppression decision-making.%针对林火蔓延影响因子的复杂性,在地理元胞自动机的基础上,提出一种应用于具有复杂树种多样性的林火蔓延模拟模型,同时借助GIS技术实现了蔓延模型的动态模拟.实验结果表明,模型可以模拟不同环境下的林火蔓延,适用于仿真分析多种因素综合作用下的林火蔓延,能够为预测分析火势蔓延趋势,估算火场形状、过火面积、蔓延速度以及优化灭火决策等提供技术支持.

  9. Application of an empirical model in CFD simulations to predict the local high temperature corrosion potential in biomass fired boilers

    International Nuclear Information System (INIS)

    To gain reliable data for the development of an empirical model for the prediction of the local high temperature corrosion potential in biomass fired boilers, online corrosion probe measurements have been carried out. The measurements have been performed in a specially designed fixed bed/drop tube reactor in order to simulate a superheater boiler tube under well-controlled conditions. The investigated boiler steel 13CrMo4-5 is commonly used as steel for superheater tube bundles in biomass fired boilers. Within the test runs the flue gas temperature at the corrosion probe has been varied between 625 °C and 880 °C, while the steel temperature has been varied between 450 °C and 550 °C to simulate typical current and future live steam temperatures of biomass fired steam boilers. To investigate the dependence on the flue gas velocity, variations from 2 m·s−1 to 8 m·s−1 have been considered. The empirical model developed fits the measured data sufficiently well. Therefore, the model has been applied within a Computational Fluid Dynamics (CFD) simulation of flue gas flow and heat transfer to estimate the local corrosion potential of a wood chips fired 38 MW steam boiler. Additionally to the actual state analysis two further simulations have been carried out to investigate the influence of enhanced steam temperatures and a change of the flow direction of the final superheater tube bundle from parallel to counter-flow on the local corrosion potential. - Highlights: • Online corrosion probe measurements in a fixed bed/drop tube reactor. • Development of an empirical corrosion model. • Application of the model in a CFD simulation of flow and heat transfer. • Variation of boundary conditions and their effects on the corrosion potential

  10. Forest fire situation analysis over forest reserve land in Tomsk petroleum province

    International Nuclear Information System (INIS)

    The paper delivers the analysis of space-time characteristics of forest fire ignition and spread in the North of Tomsk oblast, i.e. petroleum production area (Kargasok, Parabel and Teguldet districts). It also presents long-term and seasonal forest fire behavior including fire ignition and spread frequency (annual and seasonal), the fire season duration and their zonality. The main driving factors of forest fire ignition both human and natural ones are revealed

  11. Application of PRA (probabilistic risk assessments) methods for fire risk analysis

    International Nuclear Information System (INIS)

    Fire as a contributor to nuclear power plant risk has been evaluated extensively in more than 15 large-scale probabilistic risk assessments (PRA). Since their first application 9 years ago, these studies have shown that fire can be an important contributor to plant risk, an extremely plant-specific conclusion. In this article, the evolution of the application of fire risk analysis to nuclear plants is summarized. Special attention is given to Appendix R, 10CFR50; the two-stage screening approach; multilocation fires; smoke propagation; adverse effects of fire protection systems; effectiveness of fire protection systems; and fires from earthquakes. 15 refs

  12. Advanced char burnout models for the simulation of pulverized coal fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    T. Severin; S. Wirtz; V. Scherer [Ruhr-University, Bochum (Germany). Institute of Energy Plant Technology (LEAT)

    2005-07-01

    The numerical simulation of coal combustion processes is widely used as an efficient means to predict burner or system behaviour. In this paper an approach to improve CFD simulations of pulverized coal fired boilers with advanced coal combustion models is presented. In simple coal combustion models, first order Arrhenius rate equations are used for devolatilization and char burnout. The accuracy of such simple models is sufficient for the basic aspects of heat release. The prediction of carbon-in-ash is one aspect of special interest in the simulation of pulverized coal fired boilers. To determine the carbon-in-ash levels in the fly ash of coal fired furnaces, the char burnout model has to be more detailed. It was tested, in how far changing operating conditions affect the carbon-in-ash prediction of the simulation. To run several test cases in a short time, a simplified cellnet model was applied. To use a cellnet model for simulations of pulverized coal fired boilers, it was coupled with a Lagrangian particle model, used in CFD simulations, too. 18 refs., 5 figs., 5 tabs.

  13. A cut-cell immersed boundary technique for fire dynamics simulation

    Science.gov (United States)

    Vanella, Marcos; McDermott, Randall; Forney, Glenn

    2015-11-01

    Fire simulation around complex geometry is gaining increasing attention in performance based design of fire protection systems, fire-structure interaction and pollutant transport in complex terrains, among others. This presentation will focus on our present effort in improving the capability of FDS (Fire Dynamics Simulator, developed at the Fire Research Division, NIST. https://github.com/firemodels/fds-smv) to represent fire scenarios around complex bodies. Velocities in the vicinity of the bodies are reconstructed using a classical immersed boundary scheme (Fadlun and co-workers, J. Comput. Phys., 161:35-60, 2000). Also, a conservative treatment of scalar transport equations (i.e. for chemical species) will be presented. In our method, discrete conservation and no penetration of species across solid boundaries are enforced using a cut-cell finite volume scheme. The small cell problem inherent to the method is tackled using explicit-implicit domain decomposition for scalar, within the FDS time integration scheme. Some details on the derivation, implementation and numerical tests of this numerical scheme will be discussed.

  14. Numerical simulations of LNG vapor dispersion in Brayton Fire Training Field tests with ANSYS CFX

    International Nuclear Information System (INIS)

    Federal safety regulations require the use of validated consequence models to determine the vapor cloud dispersion exclusion zones for accidental liquefied natural gas (LNG) releases. One tool that is being developed in industry for exclusion zone determination and LNG vapor dispersion modeling is computational fluid dynamics (CFD). This paper uses the ANSYS CFX CFD code to model LNG vapor dispersion in the atmosphere. Discussed are important parameters that are essential inputs to the ANSYS CFX simulations, including the atmospheric conditions, LNG evaporation rate and pool area, turbulence in the source term, ground surface temperature and roughness height, and effects of obstacles. A sensitivity analysis was conducted to illustrate uncertainties in the simulation results arising from the mesh size and source term turbulence intensity. In addition, a set of medium-scale LNG spill tests were performed at the Brayton Fire Training Field to collect data for validating the ANSYS CFX prediction results. A comparison of test data with simulation results demonstrated that CFX was able to describe the dense gas behavior of LNG vapor cloud, and its prediction results of downwind gas concentrations close to ground level were in approximate agreement with the test data.

  15. Hazard analysis system of urban post-earth-quake fire based on GIS

    Institute of Scientific and Technical Information of China (English)

    李杰; 江建华; 李明浩

    2001-01-01

    The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxili-ary decision-against fire is developed.

  16. Toward an integrated system for fire, smoke, and air quality simulations

    CERN Document Server

    Kochanski, Adam K; Yedinak, Kara; Mandel, Jan; Beezley, Jonathan D; Lamb, Brian

    2014-01-01

    In this study, we describe how WRF-Sfire is coupled with WRF-Chem to construct WRFSC, an integrated forecast system for wildfire and smoke prediction. The integrated forecast system has the advantage of not requiring a simple plume-rise model and assumptions about the size and heat release from the fire in order to determine fire emissions into the atmosphere. With WRF-Sfire, wildfire spread, plume and plume-top heights are predicted directly, at every WRF timestep, providing comprehensive meteorology and fire emissions to the chemical transport model WRF-Chem. Evaluation of WRFSC was based on comparisons between available observations to the results of two WRFSC simulations. The study found overall good agreement between forecasted and observed fire spread and smoke transport for the Witch-Guejito fire. Also the simulated PM2.5 (fine particulate matter) peak concentrations matched the observations. However, the NO and ozone levels were underestimated in the simulations and the peak concentrations were mistim...

  17. Integrating Fire Behavior Models and Geospatial Analysis for Wildland Fire Risk Assessment and Fuel Management Planning

    OpenAIRE

    Alan A. Ager; Vaillant, Nicole M.; Finney, Mark A.

    2011-01-01

    Wildland fire risk assessment and fuel management planning on federal lands in the US are complex problems that require state-of-the-art fire behavior modeling and intensive geospatial analyses. Fuel management is a particularly complicated process where the benefits and potential impacts of fuel treatments must be demonstrated in the context of land management goals and public expectations. A number of fire behavior metrics, including fire spread, intensity, likelihood, and ecological risk m...

  18. FDS5 Simulation for OECD PRISME Fire Test of DOOR PRSD5

    International Nuclear Information System (INIS)

    OECD/NEA PRISME Fire Project is an international co-operation project to investigate fire propagation by means of experiments and analyses for nuclear power plant applications. This project focuses on the generation of experimental data for fire and smoke propagation from the fire room to adjacent rooms under various conditions and room configurations. In addition, analyses using computer codes are performed to understand the phenomena of interest and to produce a consistent interpretation of the experimental results. The PRISME Project is composed of series of tests named as SOURCE, DOOR, LEAK and Global Tests. The SOURCE is composed of tests to characterize the fire source, and the DOOR is to study fire and smoke propagation through an open door, while the LEAK is to investigate hot gas leakages through other modes of openings such as holes, a slot, a duct, and a partially opened door. The Global test will be conducted as integral tests on the basis of the results of the previous separate effects tests. In this paper, simulations are performed with FDS5 computer code for the DOOR Test No.5 (PRSD5) and the calculation results are compared with the corresponding experimental data to study the code capability to predict the phenomena of the hot gas propagation between two rooms

  19. Analysis of simulator training

    International Nuclear Information System (INIS)

    A method has been developed for systematic observation of operator performance in nuclear training simulators which combines training and research. It is based on generally accepted theories of operator models and decision making developed at Riso and elsewhere. It makes explicitly available the data which experienced instructors implicitly use in their assessment of operator performance. This means that the feed-back/debriefing function of the training is facilitated, it becomes possible to use normal training sessions to obtain data which can be used in further theoretical studies of e.g. operator decision making, and the generalized description of operator performance may be used to evaluate the training program as such. The method for observation is designed in cooperation with the instructors so that it does not interfere with their normal work. It is based on a detailed prior analysis of experienced transients, leading to a description of an expected performance, and some transient-in-dependent observation schemes, which are used to characterize points where the actual performance deviates from the expected performance. The analysis of the observations takes place according to the structure of a general model of analysis developed from numerous studies of operator performance, in real life and in simulators. (author)

  20. Suppression of pool fires with HRC-125 in a simulated engine nacelle.

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, David R. (INS, Inc., Lexington Park, MD); Hewson, John C.

    2007-06-01

    CFD simulations are conducted to predict the distribution of fire suppressant in an engine nacelle and to predict the suppression of pool fires by the application of this suppressant. In the baseline configuration, which is based on an installed system, suppressant is injected through four nozzles at a rate fast enough to suppress all simulated pool fires. Variations that reduce the mass of the suppression system (reducing the impact of the suppression system on meeting mission needs) are considered, including a reduction in the rate of suppressant injection, a reduction in the mass of suppressant and a reduction in the number of nozzles. In general, these variations should work to reduce the effectiveness of the suppression system, but the CFD results point out certain changes that have negligible impact, at least for the range of phenomena considered here. The results are compared with measurements where available. Comparisons with suppressant measurements are reasonable. A series of twenty-three fire suppression tests were conducted to check the predictions. The pre-test predictions were generally successful in identifying the range of successful suppression tests. In two separate cases, each where one nozzle of the suppression system was capped, the simulation results did indicate a failure to suppress for a condition where the tests indicated successful suppression. When the test-suppressant discharge rate was reduced by roughly 25%, the tests were in agreement with the predictions. That is, the simulations predict a failure to suppress slightly before observed in these cases.

  1. Surface dimming by the 2013 Rim Fire simulated by a sectional aerosol model

    Science.gov (United States)

    Yu, Pengfei; Toon, Owen B.; Bardeen, Charles G.; Bucholtz, Anthony; Rosenlof, Karen H.; Saide, Pablo E.; Da Silva, Arlindo; Ziemba, Luke D.; Thornhill, Kenneth L.; Jimenez, Jose-Luis; Campuzano-Jost, Pedro; Schwarz, Joshua P.; Perring, Anne E.; Froyd, Karl D.; Wagner, N. L.; Mills, Michael J.; Reid, Jeffrey S.

    2016-06-01

    The Rim Fire of 2013, the third largest area burned by fire recorded in California history, is simulated by a climate model coupled with a size-resolved aerosol model. Modeled aerosol mass, number, and particle size distribution are within variability of data obtained from multiple-airborne in situ measurements. Simulations suggest that Rim Fire smoke may block 4-6% of sunlight energy reaching the surface, with a dimming efficiency around 120-150 W m-2 per unit aerosol optical depth in the midvisible at 13:00-15:00 local time. Underestimation of simulated smoke single scattering albedo at midvisible by 0.04 suggests that the model overestimates either the particle size or the absorption due to black carbon. This study shows that exceptional events like the 2013 Rim Fire can be simulated by a climate model with 1° resolution with overall good skill, although that resolution is still not sufficient to resolve the smoke peak near the source region.

  2. FASA – Fire Airborne Spectral Analysis of natural disasters

    Directory of Open Access Journals (Sweden)

    F. Schrandt

    2006-06-01

    Full Text Available At present the authors are developing the system FASA, an airborne combination of a Fourier Transform Spectrometer and an imaging system. The aim is to provide a system that is usable to investigate and monitor emissions from natural disasters such as wild fires and from volcanoes. Besides temperatures and (burned areas FASA will also provide concentration profiles of the gaseous combustion products. These data are needed to improve the knowledge of the effects of such emissions on the global ecosystem. The paper presents a description of the instrumentation, the data evaluation procedure and shows first results of retrieval calculations based on simulated spectra.

  3. Two-dimensional simulations of possible mesoscale effects of nuclear war fires 2. Model results

    International Nuclear Information System (INIS)

    The two-dimensional mesoscale meteorological model and the aerosol model described in the companion papaer by Giorgi [this issue] are used to investigate mesoscale effects induced by atmospheric injections of purely absorbing smoke from nuclear war fires. Simulations are carried out for different fire types (city center, suburban, and forest fires), aerosol loadings, particle properties, and atmospheric conditions. We analyze three effects which develop on spatial scales of 10--500 km and time scales of 1--2 days and can be important for assessments of environmental impacts of nuclear war: (1) smoke-induced formation of clouds and precipitation and efficiency of smoke removal; (2) smoke vertical transport; and (3) surface cooling induced by the smoke absorption. In convectively unstable and moist environments the low-level uplifting induced by the smoke heating can initiate convective precipitation. In the absence of substantial moisture sources from the fires, precipitation develops mostly at the edges of the smoke plumes and is associated with the inhomogeneities in the smoke distribution, since these allow low-level smoke heating. When the smoke is dispersed by the atmospheric winds and attains a more homogeneous distribution, most of the heating takes place at more stable higher altitudes, the smoke shielding stabilizes the lower troposhere and precipitation formation is hindered. Wet removal dominates dry removal processes and its efficiency depends on the properties and vertical distribution of the injected aerosol. In a wide variety of experiments, the fraction of the total injected smoke mass removed during 48 hour simulations varied from 3 to 20% for injections from suburban fires, from 10 to 20% for forest fires, and 1% for city center fires

  4. Simulator training analysis

    International Nuclear Information System (INIS)

    This paper presents a suggestion for systematic collection of data during the normal use of training simulators, with the double purpose of supporting trainee debriefing and providing data for further theoretical studies of operator performance. The method is based on previously described models of operator performance and decision-making, and is a specific instance of the general method for analysis of operator performance data. The method combines a detailed transient-specific description of the expected performance with transient-independent tools for observation of critical activities. (author)

  5. Mapping forest fire risk zones with spatial data and principal component analysis

    Institute of Scientific and Technical Information of China (English)

    XU Dong; Guofan Shao; DAI Limin; HAO Zhanqing; TANG Lei; WANG Hui

    2006-01-01

    By integrating forest inventory data with remotely sensed data, new data layers for factors that affect forest fire potentials were generated for Baihe Forestry Bureau in Jilin Province of China. The principle component analysis was used to sort out the relationships between forest fire potentials and environmental factors. The classifications of these factors were performed with GIS, generating three maps: a fuel-based fire risk map, a topography-based fire risk map, and an anthropogenic-factor fire risk map. These three maps were then synthesized to generate the final fire risk map. The linear regression method was used to analyze the relationship between an area-weighted value of forest fire risks and the frequency of historical forest fires at each forest farm. The results showed that the most important factor contributing to forest fire ignition was topography, followed by anthropogenic factors.

  6. Thermodynamic analysis of a biomass-fired Kalina cycle with regenerative heater

    International Nuclear Information System (INIS)

    The biomass fuel is a renewable energy resource, which is viewed as a promising alternative to fossil energy. This paper investigates a biomass-fired Kalina cycle with a regenerative heater which is generally utilized to heat the feedwater and to increase the efficiency in coal-fired steam power plant. The mathematical model of the biomass-fired Kalina cycle with a regenerative heater is established to conduct numerical simulation. A parametric analysis is conducted to examine the effects of some key thermodynamic parameters on the system performance. Furthermore, a parametric optimization is carried out by genetic algorithm to obtain the optimum performance of system. The results demonstrate that there exists an optimum extraction pressure and its corresponding maximum fraction of flow extracted from turbine to maximize the net power output and system efficiency. In addition, a higher turbine inlet pressure or turbine inlet temperature leads to higher net power output and system efficiency. And net power output and system efficiency increases as separator temperature rises. The optimization result of the biomass-fired Kalina cycle with/without regenerative heater indicates the system is more efficient when regenerative heater is added. - Highlights: • Kalina cycle with a regenerative heater is driven by biomass boiler. • The effects of several parameters on system performance are examined. • Parametric optimization is conducted by GA to obtain optimum performance

  7. Fire hazard analysis of Rocky Flats Building 776/777 duct systems

    Energy Technology Data Exchange (ETDEWEB)

    DiNenno, P.J.; Scheffey, J.L.; Gewain, R.G.; Shanley, J.H. Jr. [Hughes Associates, Inc., Wheaton, MD (United States)

    1988-12-01

    The objective of this analysis is to determine if ventilation ductwork in Building 776/777 will maintain their structural integrity during expected fire conditions as well as standard design fires typically used to ascertain fire resistance ratings. If the analysis shows that ductwork will not maintain structural integrity, the impact of this failure will be determined and analyzed, and alternative solutions recommended. Associated with this analysis is the development of a computer fire model which can be used as an engineering tool in analyzing the effect of fires on ductwork in other areas and buildings.

  8. Fire fighting trainers' exposure to carcinogenic agents in smoke diving simulators.

    Science.gov (United States)

    Laitinen, Juha; Mäkelä, Mauri; Mikkola, Jouni; Huttu, Ismo

    2010-01-15

    It is well known that fire fighters are potentially exposed to various carcinogenic agents at a fire scene. An almost unheeded issue, however, is fire fighters' exposure to carcinogenic agents in smoke diving simulators. Biomonitoring (urinary muconic acid, 1-naphthol and 1-pyrenol), dermal (polycyclic aromatic hydrocarbons) and occupational hygiene measurements (cyanides, hydrogen cyanide, polycyclic aromatic hydrocarbons, volatile organic compounds and formaldehyde) were used to determine how the burning material, the type of simulator and protective clothing used affect fire fighting trainers' exposure. The highest excretion of 1-pyrenol (sampled 6h after end of exposure, in average 4.3-9.2nmol/L) and emissions of benzene (1.0-2.5mg/m(3)) and hydrogen cyanide (0.2-0.9mg/m(3)) were measured during the burning of conifer plywood and chipboard, and the lowest when pure pine and spruce wood (1.5nmol/L, 0.6mg/m(3), and 0.05mg/m(3)) was burned. However the safest burning material seemed to be propane (1.0nmol/L, 0.2mg/m(3), and not measured). The type of simulator used affected trainers' exposure very clearly. The highest dermal whole body exposures to polycyclic aromatic hydrocarbons were measured in the fire house simulator (in average 1200ng/cm(2)). Clearly lower exposure levels were measured in container training sessions (760ng/cm(2)), where the average dermal exposure level was 35% lower than in the fire house. The exposure levels (30ng/cm(2)) in the gas simulator in turn, were only 4% of the levels in container training sessions. The amount of polycyclic aromatic hydrocarbons decreased by 80% on trainers' hands when they used under gloves (in average 8.7ng/cm(2)) compared to those (48.4ng/cm(2)) who did not. There was not difference in protection efficiency against polycyclic aromatic hydrocarbons between tested fire suits (Brage and Bristol). PMID:19576276

  9. Fire Research Enclosure

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Simulates submarine fires, enclosed aircraft fires, and fires in enclosures at shore facilities . DESCRIPTION: FIRE I is a pressurizable, 324 cu m(11,400...

  10. Research on solar aided coal-fired power generation system and performance analysis

    Institute of Scientific and Technical Information of China (English)

    YANG YongPing; CUI YingHong; HOU HongJuan; GUO XiYan; YANG ZhiPing; WANG NinLing

    2008-01-01

    Integrationg rating solar power utilization systems with coal-fired power units, the solar aided coal-fired power generation (SACPG) shows a significant prospect for the large-scale utilization of solar energy and energy saving of thermal power units. The methods and mechanism of system integration were studied. The parabolic trough solar collectors were used to collect solar energy and the integration scheme of SACPG system was determined considering the matching of working fluid flows and energy flows. The thermodynamic characteristics of solar thermal power generation and their effects on the performance of thermal power units were studied, and based on this the integration and optimization model of system structure and parameters were built up. The integration rules and coupling mecha-nism of SACPG systems were summarized in accordance with simulation results. The economic analysis of this SACPG system showed that the solar LEC of a of SEGS, 0.14 S/kW. h.

  11. Computational analysis of mixing and transport of air and fuel co-fired combustor

    International Nuclear Information System (INIS)

    Computational analysis for air fuel mixing and transport in a combustor used for co fired burner has been done by RANS (Reynolds-Averaged Navier-Stokes) model comparing with 3D (Three Dimensional) LES (Large Eddy Simulation). To investigate the better turbulence level and mixing within co fired combustor using the solid fuel biomass with coal is main purpose of this research work. The results show the difference in flow predicted by the two models, LES give better results than the RANS. For compressible flow the LES results show more swirling effect, The velocity decays along axial and radial distance for both swirling and non-swirling jet. Because of no slip condition near boundary the near the wall velocity is about zero. (author)

  12. Computational Analysis of Mixing and Transport of Air and Fuel in Co-Fired Combustor

    Directory of Open Access Journals (Sweden)

    Javaid Iqbal

    2015-01-01

    Full Text Available Computational analysis for air fuel mixing and transport in a combustor used for co fired burner has been done by RANS (Reynolds-Averaged Navier?Stokes model comparing with 3D (Three Dimensional LES (Large Eddy Simulation. To investigate the better turbulence level and mixing within co fired combustor using the solid fuel biomass with coal is main purpose of this research work. The results show the difference in flow predicted by the two models, LES give better results than the RANS. For compressible flow the LES results show more swirling effect, The velocity decays along axial and radial distance for both swirling and non-swirling jet. Because of no slip condition near boundary the near the wall velocity is about zero

  13. Statistical and spatial analysis of forest fire ignition points: a study case in South of France

    OpenAIRE

    Lampin, C.; Jappiot, M.; Morge, D.; Vennetier, M.

    2006-01-01

    In south of France, the forest fire origin is mainly due to human activities. It represents 96 % of the fire causes. A study concerning spatial distribution of past fire ignition points was performed trying to point out areas where the fire ignition is important, in order to know. the repartition of ignition points and to model its distribution. A statistical data analysis, at a French area level, has allowed to relate ignition point density with global indicators of human activity and to dev...

  14. Integrating Fire Behavior Models and Geospatial Analysis for Wildland Fire Risk Assessment and Fuel Management Planning

    Directory of Open Access Journals (Sweden)

    Alan A. Ager

    2011-01-01

    Full Text Available Wildland fire risk assessment and fuel management planning on federal lands in the US are complex problems that require state-of-the-art fire behavior modeling and intensive geospatial analyses. Fuel management is a particularly complicated process where the benefits and potential impacts of fuel treatments must be demonstrated in the context of land management goals and public expectations. A number of fire behavior metrics, including fire spread, intensity, likelihood, and ecological risk must be analyzed for multiple treatment alternatives. The effect of treatments on wildfire impacts must be considered at multiple scales. The process is complicated by the lack of data integration among fire behavior models, and weak linkages to geographic information systems, corporate data, and desktop office software. This paper describes our efforts to build a streamlined fuel management planning and risk assessment framework, and an integrated system of tools for designing and testing fuel treatment programs on fire-prone wildlands.

  15. Global fire activity patterns (1996-2006) and climatic influence: an analysis using World Fire Atlas

    OpenAIRE

    Le Page, Y.; J. M. C. Pereira; Trigo, R.; Camara, C.; Oom, D.; Mota, B.

    2008-01-01

    Vegetation fires have been acknowledged as an environmental process of global scale, which affects the chemical composition of the troposphere, and has profound ecological and climatic impacts. However, considerable uncertainty remains, especially concerning intra and inter-annual variability of fire incidence. The main goals of our globalscale study were to characterise spatial-temporal patterns of fire activity, to identify broad geographical areas with similar veget...

  16. Gusty, gaseous flows of FIRE: galactic winds in cosmological simulations with explicit stellar feedback

    Science.gov (United States)

    Muratov, Alexander L.; Kereš, Dušan; Faucher-Giguère, Claude-André; Hopkins, Philip F.; Quataert, Eliot; Murray, Norman

    2015-12-01

    We present an analysis of the galaxy-scale gaseous outflows from the Feedback in Realistic Environments (FIRE) simulations. This suite of hydrodynamic cosmological zoom simulations resolves formation of star-forming giant molecular clouds to z = 0, and features an explicit stellar feedback model on small scales. Our simulations reveal that high-redshift galaxies undergo bursts of star formation followed by powerful gusts of galactic outflows that eject much of the interstellar medium and temporarily suppress star formation. At low redshift, however, sufficiently massive galaxies corresponding to L* progenitors develop stable discs and switch into a continuous and quiescent mode of star formation that does not drive outflows far into the halo. Mass-loading factors for winds in L* progenitors are η ≈ 10 at high redshift, but decrease to η ≪ 1 at low redshift. Although lower values of η are expected as haloes grow in mass over time, we show that the strong suppression of outflows with decreasing redshift cannot be explained by mass evolution alone. Circumgalactic outflow velocities are variable and broadly distributed, but typically range between one and three times the circular velocity of the halo. Much of the ejected material builds a reservoir of enriched gas within the circumgalactic medium, some of which could be later recycled to fuel further star formation. However, a fraction of the gas that leaves the virial radius through galactic winds is never regained, causing most haloes with mass Mh ≤ 1012 M⊙ to be deficient in baryons compared to the cosmic mean by z = 0.

  17. A Naval Marksmanship Training Transfer Study The Use of Indoor Simulated Marksmanship Trainers to Train for Live Fire

    OpenAIRE

    Jensen, Timothy; Woodson, John

    2012-01-01

    The use of simulation to train watchstanders in marksmanship would provide a valuable and flexible training asset to the Navy, resulting in minimal lost training opportunities due to operational commitments at sea. We hypothesized that (1) simulation-based marksmanship training would transfer to live fire better than dry fire training, and (2) the experimental (simulation) group would have a better chance of retaining their marksmanship skills than the control group after two or four weeks wi...

  18. Spatio-Temporal Analysis of Forest Fire Risk and Danger Using LANDSAT Imagery

    Directory of Open Access Journals (Sweden)

    Ömer Kücük

    2008-06-01

    Full Text Available Computing fire danger and fire risk on a spatio-temporal scale is of crucial importance in fire management planning, and in the simulation of fire growth and development across a landscape. However, due to the complex nature of forests, fire risk and danger potential maps are considered one of the most difficult thematic layers to build up. Remote sensing and digital terrain data have been introduced for efficient discrete classification of fire risk and fire danger potential. In this study, two time-series data of Landsat imagery were used for determining spatio-temporal change of fire risk and danger potential in Korudag forest planning unit in northwestern Turkey. The method comprised the following two steps: (1 creation of indices of the factors influencing fire risk and danger; (2 evaluation of spatio-temporal changes in fire risk and danger of given areas using remote sensing as a quick and inexpensive means and determining the pace of forest cover change. Fire risk and danger potential indices were based on species composition, stand crown closure, stand development stage, insolation, slope and, proximity of agricultural lands to forest and distance from settlement areas. Using the indices generated, fire risk and danger maps were produced for the years 1987 and 2000. Spatio-temporal analyses were then realized based on the maps produced. Results obtained from the study showed that the use of Landsat imagery provided a valuable characterization and mapping of vegetation structure and type with overall classification accuracy higher than 83%.

  19. SIMULATION OF FIRE DYNAMICS WITH VARIOUS GROWTH RATE IN PREMISES WITH NATURAL VENTILATION

    Directory of Open Access Journals (Sweden)

    V. V. Nevdakh

    2015-08-01

    Full Text Available Computer simulation of the initial fire stage dynamics with various growth rate have been carried out with the help of FDS software. In case of a quick fire 1055 kW heat liberation has been reached in accordance with quadratic law within 100 seconds, averagely within 250 seconds and within 500 seconds when the fire rate is slow. Source of fire has been located on the floor and at the height of 2 m. A doorway of 0.8×2.0 m size and two 0.8×0.1 m openings have been used as ventilation holes. One opening has been located at the bottom over the floor and the other one has been positioned under the ceiling. It has been established that in the process of their development fires change their character in the following way: at the initial stage they are controlled by inflammable materials and then the fires are controlled by oxygen. At the first stage heat liberation is changed in accordance with the same law which is used for mass rate of an inflammable material and flame combustion is observed only in the field of the fire source. At the second stage heat liberation dynamics has a form of pulsations which are irregular in amplitude and duration and the dynamics becomes dependable on ventilation conditions. At this stage flame combustion in the source zone and/or self-ignition in the smoke layer provide a corresponding contribution in fire heat liberation.It has been determined that two layers have been formed in case of a fire in the premises with ventilation in the spatial distribution of temperature and air fumigation. These top and bottom layers are practically uniform and they are characterized by irregular pulsations of the parameters which are due to smoke self-ignition occurrence. The paper shows relationship of these distributions with spatial distribution of air pressure changes in the premises during a fire. A significant dependence of heat liberation dynamics on fire source location height is observed at all fire growth rates. An increase

  20. Fire risk analysis for nuclear power plants: Methodological developments and applications

    International Nuclear Information System (INIS)

    A methodology to quantify the risk from fires in nuclear power plants is described. This methodology combines engineering judgment, statistical evidence, fire phenomenology, and plant system analysis. It can be divided into two major parts: (1) fire scenario identification and quantification, and (2) analysis of the impact on plant safety. This article primarily concentrates on the first part. Statistical analysis of fire occurrence data is used to establish the likelihood of ignition. The temporal behaviors of the two competing phenomena, fire propagation and fire detection and suppression, are studied and their characteristic times are compared. Severity measures are used to further specialize the frequency of the fire scenario. The methodology is applied to a switchgear room of a nuclear power plant

  1. Safety analysis of the existing 851 Firing Facility

    International Nuclear Information System (INIS)

    A safety analysis was performed to determine if normal operations and/or potential accidents at the 851 Firing Facility at Site 300 could present undue hazards to the general public, personnel at Site 300, or have an adverse effect on the environment. The normal operations and credible accidents that might have an effect on these facilities or have off-site consequences were considered. It was determined by this analysis that all but two of the hazards were either low or of the type or magnitude routinely encountered and/or accepted by the public. The exceptions were the linear accelerator and explosives, which were classified as moderate hazards per the requirements given in DOE Order 5481.1A. This safety analysis concluded that the operation at this facility will present no undue risk to the health and safety of LLNL employees or the public

  2. Safety analysis of the existing 850 Firing Facility

    International Nuclear Information System (INIS)

    A safety analysis was performed to determine if normal operations and/or potential accidents at the 850 Firing Facility at Site 300 could present undue hazards to the general public, personnel at Site 300, or have an adverse effect on the environment. The normal operations and credible accidents that might have an effect on these facilities or have off-site consequences were considered. It was determined by this analysis that all but one of the hazards were either low or of the type or magnitude routinely encountered and/or accepted by the public. The exception was explosives, which was classified as a moderate hazard per the requirements given in DOE Order 5481.1A. This safety analysis concluded that the operation at this facility will present no undue risk to the health and safety of LLNL employees or the public

  3. CFD analysis of the effects of co-firing biomass with coal

    Energy Technology Data Exchange (ETDEWEB)

    Ghenai, Chaouki [Mechanical Engineering Department, College of Engineering and Computer Science, Florida Atlantic University, Boca Raton, Florida 33431 (United States); Janajreh, Isam [Masder Institute of Science and Technology, Abu Dhabi (United Arab Emirates)

    2010-08-15

    Computational Fluid Dynamics (CFD) analysis of the effects of co-firing biomass with coal is presented in this study. Coal/biomass co-firing is a complex problem that involves gas and particle phases, along with the effect of the turbulence on the chemical reactions. The CFD analysis includes the prediction of volatile evolution and char burnout from the co-pulverized coal/biomass particles along with the simulation of the combustion chemistry occurring in the gas phase. The mathematical models consist of models for turbulent flow (RNG k-{epsilon} model); gas phase combustion (two-mixture fractions/PDF model); particles dispersion by turbulent flow (stochastic tracking model); coal/biomass particles devolatilization (two competing rates Kobayashi model); heterogeneous char reaction (kinetics/diffusion-limited rate model); and radiation (P-1 radiation model). The coal used is a Canadian high sulfur bituminous coal. The coal was blended with 5-20% wheat straw (thermal basis) for co-firing. The effect of the percentage of biomass blended with coal on the flow field, gas and particle temperature distribution, particles trajectories and gas emissions (CO{sub 2} and NO{sub x}) are presented. One important result is the reduction of NO{sub x} and CO{sub 2} emissions when using co-combustion. This reduction depends on the proportion of biomass (wheat straw) blended with coal. (author)

  4. Fiber beam model for fire response simulation of axially loaded concrete filled tubular columns

    OpenAIRE

    Ibáñez Usach, Carmen; Romero, Manuel L.; Hospitaler Pérez, Antonio

    2013-01-01

    This paper presents a fiber beam model for the fire response simulation of concrete filled tubular columns of circular section under concentric axial load. The model consists of two parallel components, one with a circular tubular steel section, and the other with a solid circular concrete section. The components interact with nonlinear longitudinal and transverse links at the end nodes. The element is formulated on a system without rigid body modes and accounts for large displacement geometr...

  5. Analysis of underground fires in Polish hard coal mines

    Institute of Scientific and Technical Information of China (English)

    WACHOWICZ Jan

    2008-01-01

    In the period of the first twenty years after World War II the number of fires in Polish hard coal mines reached annually the value of several thousands of cases. About 80% of fires constituted spontaneous fires. Investigations into the development of new methods of fire hazard prediction and implementation of new methods and means of fire prevention as well as the introduction of prohibition concerning the use of products manufactured of combustible organic materials in underground mine workings re-duced considerably the hazard of underground fire rise. The worked out at the Central Mining Institute (GIG) new method of un-derground fire prediction allows the correct selection of fire prevention means. The introduction into common use of fire-resistant conveyor belts, the main factor giving rise to spontaneous fires, and methods of assessment of their fire resistance eliminated prac-tically the fire hazard. These activities contributed in an efficient way to the reduction of the number of underground fires to a sa-tisfactory level.

  6. Validation/Uncertainty Quantification for Large Eddy Simulations of the heat flux in the Tangentially Fired Oxy-Coal Alstom Boiler Simulation Facility

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.J.; Eddings, E.G.; Ring, T.; Thornock, J.; Draper, T.; Isaac, B.; Rezeai, D.; Toth, P.; Wu, Y.; Kelly, K.

    2014-08-01

    The objective of this task is to produce predictive capability with quantified uncertainty bounds for the heat flux in commercial-scale, tangentially fired, oxy-coal boilers. Validation data came from the Alstom Boiler Simulation Facility (BSF) for tangentially fired, oxy-coal operation. This task brings together experimental data collected under Alstom’s DOE project for measuring oxy-firing performance parameters in the BSF with this University of Utah project for large eddy simulation (LES) and validation/uncertainty quantification (V/UQ). The Utah work includes V/UQ with measurements in the single-burner facility where advanced strategies for O2 injection can be more easily controlled and data more easily obtained. Highlights of the work include: • Simulations of Alstom’s 15 megawatt (MW) BSF, exploring the uncertainty in thermal boundary conditions. A V/UQ analysis showed consistency between experimental results and simulation results, identifying uncertainty bounds on the quantities of interest for this system (Subtask 9.1) • A simulation study of the University of Utah’s oxy-fuel combustor (OFC) focused on heat flux (Subtask 9.2). A V/UQ analysis was used to show consistency between experimental and simulation results. • Measurement of heat flux and temperature with new optical diagnostic techniques and comparison with conventional measurements (Subtask 9.3). Various optical diagnostics systems were created to provide experimental data to the simulation team. The final configuration utilized a mid-wave infrared (MWIR) camera to measure heat flux and temperature, which was synchronized with a high-speed, visible camera to utilize two-color pyrometry to measure temperature and soot concentration. • Collection of heat flux and temperature measurements in the University of Utah’s OFC for use is subtasks 9.2 and 9.3 (Subtask 9.4). Several replicates were carried to better assess the experimental error. Experiments were specifically designed for the

  7. Analysis of biomass co-firing systems in Taiwan power markets using linear complementarity models

    International Nuclear Information System (INIS)

    Biomass co-firing systems in power plants generate electric power by the simultaneous combustion of biomass and fossil fuels. The co-firing process reduces investment costs by converting biomass energy into electricity in existing conventional power plants. Biomass co-firing significantly reduces carbon dioxide and sulfur dioxide emissions in power generation. To meet the increase in biomass demand, this paper has considered systematic energy crop production, which is expected to increase in the near future. Our aim is to analyze biomass co-firing systems in the Taiwanese electricity market. In this paper, we study two emerging biomass feedstocks: switchgrass and Miscanthus. We focus on the impact of energy crop co-firing on carbon dioxide and sulfur dioxide emissions for electricity generation. A Nash-Cournot competition model, which simulates potential biomass co-firing scenarios, is formulated for power markets. A case study conducted in the Taiwanese electricity market showed that biomass co-firing lowers total electricity demand and sale. Miscanthus is more economical than switchgrass in terms of the production cost and the land required to generate biopower for the same levels of biomass co-firing. - Highlights: → Biomass co-firing system in electricity market is analyzed in this paper. → The research studies the impact of two energy crops in co-firing system. → This paper conducts a case study of co-firing system in Taiwan power markets.

  8. Analysis of biomass co-firing systems in Taiwan power markets using linear complementarity models

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Ming-Che; Lin, Chun-Hung [Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Chou, Chun-An [Department of Industrial and Systems Engineering, Rutgers University, 96 Frelinghuysen Rd, Piscataway, NJ 08854 (United States); Hsu, Shao-Yiu [Department of Geography and Environmental Engineering, Johns Hopkins University, 3400, N Charles St, Ames-313, Baltimore, MD 21218 (United States); Wen, Tzai-Hung, E-mail: wenthung@ntu.edu.tw [Department of Geography, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China)

    2011-08-15

    Biomass co-firing systems in power plants generate electric power by the simultaneous combustion of biomass and fossil fuels. The co-firing process reduces investment costs by converting biomass energy into electricity in existing conventional power plants. Biomass co-firing significantly reduces carbon dioxide and sulfur dioxide emissions in power generation. To meet the increase in biomass demand, this paper has considered systematic energy crop production, which is expected to increase in the near future. Our aim is to analyze biomass co-firing systems in the Taiwanese electricity market. In this paper, we study two emerging biomass feedstocks: switchgrass and Miscanthus. We focus on the impact of energy crop co-firing on carbon dioxide and sulfur dioxide emissions for electricity generation. A Nash-Cournot competition model, which simulates potential biomass co-firing scenarios, is formulated for power markets. A case study conducted in the Taiwanese electricity market showed that biomass co-firing lowers total electricity demand and sale. Miscanthus is more economical than switchgrass in terms of the production cost and the land required to generate biopower for the same levels of biomass co-firing. - Highlights: > Biomass co-firing system in electricity market is analyzed in this paper. > The research studies the impact of two energy crops in co-firing system. > This paper conducts a case study of co-firing system in Taiwan power markets.

  9. Fire fatalities among children: an analysis across Philadelphia's census tracts.

    OpenAIRE

    Shai, Donna; Lupinacci, Paul

    2003-01-01

    OBJECTIVE: This study investigates the possible causes of high levels of residential fire deaths to children younger than 15 years of age in Philadelphia from 1989 to 2000. METHODS: The authors analyzed 246 deaths from 146 residential fires by census tract in Philadelphia using both individual level data and aggregate level data drawn from the records of the Fire Marshall's Office. Death rates by age and sex were calculated using the 1990 Census. Data on fires from official records were combi...

  10. Mapping Fire Severity Using Imaging Spectroscopy and Kernel Based Image Analysis

    Science.gov (United States)

    Prasad, S.; Cui, M.; Zhang, Y.; Veraverbeke, S.

    2014-12-01

    Improved spatial representation of within-burn heterogeneity after wildfires is paramount to effective land management decisions and more accurate fire emissions estimates. In this work, we demonstrate feasibility and efficacy of airborne imaging spectroscopy (hyperspectral imagery) for quantifying wildfire burn severity, using kernel based image analysis techniques. Two different airborne hyperspectral datasets, acquired over the 2011 Canyon and 2013 Rim fire in California using the Airborne Visible InfraRed Imaging Spectrometer (AVIRIS) sensor, were used in this study. The Rim Fire, covering parts of the Yosemite National Park started on August 17, 2013, and was the third largest fire in California's history. Canyon Fire occurred in the Tehachapi mountains, and started on September 4, 2011. In addition to post-fire data for both fires, half of the Rim fire was also covered with pre-fire images. Fire severity was measured in the field using Geo Composite Burn Index (GeoCBI). The field data was utilized to train and validate our models, wherein the trained models, in conjunction with imaging spectroscopy data were used for GeoCBI estimation wide geographical regions. This work presents an approach for using remotely sensed imagery combined with GeoCBI field data to map fire scars based on a non-linear (kernel based) epsilon-Support Vector Regression (e-SVR), which was used to learn the relationship between spectra and GeoCBI in a kernel-induced feature space. Classification of healthy vegetation versus fire-affected areas based on morphological multi-attribute profiles was also studied. The availability of pre- and post-fire imaging spectroscopy data over the Rim Fire provided a unique opportunity to evaluate the performance of bi-temporal imaging spectroscopy for assessing post-fire effects. This type of data is currently constrained because of limited airborne acquisitions before a fire, but will become widespread with future spaceborne sensors such as those on

  11. Comparative analysis of mass forest and nuclear fires

    International Nuclear Information System (INIS)

    The massive forest fires that occurred in Siberia in 1915 are analyzed for the effects on regional and global climates in order to depict the impact of forest fires generated from war time use of nuclear weapons. The mathematical equations depict the index of danger conditions for starting forest fires and the resulting atmospheric conditions generated. 18 refs., 3 figs

  12. Improvement of fire protection measures for nuclear power plants

    International Nuclear Information System (INIS)

    Improvements of fire protection measures for nuclear power plants were performed as following items: Collection of necessary data and evaluation of parameters, Walk down in the typical BWR and PWR plants, Application of developed analysis method to actual plants, Development of fire hazard analysis manual. With regard to fire tests for the fire data acquisition, the test plan was made about cable fire, oil fire and electric cabinet fire in the concrete test facilities. Implementation of fire hazard analysis model and simulation were performed as following items: Fire analysis codes FDS, CFAST were implemented in order to analyze the fire progression phenomena, Trial calculation of fire hazard for typical NPP by FDS were performed for the Auxiliary feed water pump room (PWR) and the High pressure coolant flooder pump room (BWR). (author)

  13. Wildland fire management. Volume 1: Prevention methods and analysis. [systems engineering approach to California fire problems

    Science.gov (United States)

    Weissenberger, S. (Editor)

    1973-01-01

    A systems engineering approach is reported for the problem of reducing the number and severity of California's wildlife fires. Prevention methodologies are reviewed and cost benefit models are developed for making preignition decisions.

  14. EVENT-DRIVEN SIMULATION OF INTEGRATE-AND-FIRE MODELS WITH SPIKE-FREQUENCY ADAPTATION

    Institute of Scientific and Technical Information of China (English)

    Lin Xianghong; Zhang Tianwen

    2009-01-01

    The evoked spike discharges of a neuron depend critically on the recent history of its electrical activity. A well-known example is the phenomenon of spike-frequency adaptation that is a commonly observed property of neurons. In this paper, using a leaky integrate-and-fire model that includes an adaptation current, we propose an event-driven strategy to simulate integrate-and-fire models with spike-frequency adaptation. Such approach is more precise than traditional clock-driven numerical integration approach because the timing of spikes is treated exactly. In experiments, using event-driven and clock-driven strategies we simulated the adaptation time course of single neuron and the random network with spike-timing dependent plasticity, the results indicate that (1) the temporal precision of spiking events impacts on neuronal dynamics of single as well as network in the different simulation strategies and (2) the simulation time scales linearly with the total number of spiking events in the event-driven simulation strategies.

  15. An Information Diffusion Technique for Fire Risk Analysis

    Institute of Scientific and Technical Information of China (English)

    刘静; 黄崇福

    2004-01-01

    There are many kinds of fires occurring under different conditions. For a specific site, it is difficult to collect sufficient data for analyzing the fire risk. In this paper, we suggest an information diffusion technique to analyze fire risk with a small sample. The information distribution method is applied to change crisp observations into fuzzy sets, and then to effectively construct a fuzzy relationship between fire and surroundings. With the data of Shanghai in winter, we show how to use the technique to analyze the fire risk.

  16. Laboratory Investigations of the High Temperature Corrosion of Various Materials in Simulated oxy-fuel and Conventional Coal Firing

    International Nuclear Information System (INIS)

    Laboratory exposures in horizontal tube furnaces were conducted to test various materials for corrosion resistance in simulated oxy-fuel firing and conventional coal firing environments. Two different exposures were done at 630 C for 672 hours. The reaction atmosphere, consisting of CO2, H2O, O2, N2 and SO2, was mixed to resemble that of oxy-fuel firing in the first exposure and that of conventional coal firing in the second exposure (N2 was added during the second exposure only). Four different materials were tested in the first exposure; Sanicro 63, Alloy 800HT, 304L and 304HCu. In the second exposure four different materials were tested; 304L, Alloy 800HT, Kanthal APMT and NiCrAl. Apart from cleaned sample coupons, some samples pre-exposed in a test rig under oxy-fuel conditions with lignite as fuel and some pre-exposed with bituminous coal as fuel were investigated in the first exposure. In the second exposure some samples were pre-exposed in a rig under conventional firing conditions with lignite as fuel. The corrosion attack on the investigated samples was analysed by gravimetry, x-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive x-ray (EDX). The SEM/EDX analysis was made on both the sample envelope and metallographic cross sections of the samples. The results show that there is small difference in the corrosion attack between the two environments. There was also little difference in oxide morphology and composition between cleaned samples and pre-exposed samples of the same material. The austenitic chromia former 304HCu suffered the most extensive corrosion attack in the oxy-fuel environment. In the conventional air firing environment 304L showed the highest mass gain. Chromia formers with higher chromium concentrations performed better, especially the super austenitic Alloy 800HT, with its high chromium concentration, formed a thin and protective corundum type oxide. The nickel based Sanicro 63 showed very low corrosion

  17. Laboratory Investigations of the High Temperature Corrosion of Various Materials in Simulated oxy-fuel and Conventional Coal Firing

    Energy Technology Data Exchange (ETDEWEB)

    Folkeson, N.; Pettersson, J.; Svensson, J.E. [Chalmers Univ. of Technology (Sweden); Hjornhede, A. [Vattenfall Power Consultant AB (Sweden); Montgomery, M. [Vattenfall Heat Nordic/DTU Mekanik (Denmark); Bjurman, M. [Vattenfall Research and Development AB (Sweden)

    2009-07-01

    Laboratory exposures in horizontal tube furnaces were conducted to test various materials for corrosion resistance in simulated oxy-fuel firing and conventional coal firing environments. Two different exposures were done at 630 C for 672 hours. The reaction atmosphere, consisting of CO{sub 2}, H{sub 2}O, O{sub 2}, N{sub 2} and SO{sub 2}, was mixed to resemble that of oxy-fuel firing in the first exposure and that of conventional coal firing in the second exposure (N{sub 2} was added during the second exposure only). Four different materials were tested in the first exposure; Sanicro 63, Alloy 800HT, 304L and 304HCu. In the second exposure four different materials were tested; 304L, Alloy 800HT, Kanthal APMT and NiCrAl. Apart from cleaned sample coupons, some samples pre-exposed in a test rig under oxy-fuel conditions with lignite as fuel and some pre-exposed with bituminous coal as fuel were investigated in the first exposure. In the second exposure some samples were pre-exposed in a rig under conventional firing conditions with lignite as fuel. The corrosion attack on the investigated samples was analysed by gravimetry, x-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive x-ray (EDX). The SEM/EDX analysis was made on both the sample envelope and metallographic cross sections of the samples. The results show that there is small difference in the corrosion attack between the two environments. There was also little difference in oxide morphology and composition between cleaned samples and pre-exposed samples of the same material. The austenitic chromia former 304HCu suffered the most extensive corrosion attack in the oxy-fuel environment. In the conventional air firing environment 304L showed the highest mass gain. Chromia formers with higher chromium concentrations performed better, especially the super austenitic Alloy 800HT, with its high chromium concentration, formed a thin and protective corundum type oxide. The nickel based

  18. Fire analysis and combustion products in a wood processing industry facility

    OpenAIRE

    Mravlje, Anja

    2014-01-01

    In industry the use of materials and substances that pose a threat to human health and life, especially in case of fire, has increased. Therefore it has become more and more important that industrial facilities be designed properly and that, in case of fire, they not pose a danger to human life and health and the environment. For the assessment of fire safety, fire simulations with computer software are made. In the first part of the thesis, I summarized the basics of combustion, combustion p...

  19. Evaluation of a Main Control Room Fire Risk

    International Nuclear Information System (INIS)

    In this study, the scenarios of forced abandonment caused by an ex-MCR fire were not addressed because their contribution to an MCR fire risk is expected to be insignificant. This paper presented the risk evaluation results of an MCR fire for Hanul Unit 3 using fire simulations, a fire human reliability analysis method, and the IPRO-ZONE. Fire scenarios were classified into forced abandonment of MCR and non-abandonment of it. They were further classified into propagating and non-propagating fire scenarios. The CDF of an MCR fire was quantified as 5.659E-7/yr. Compared with the previous industry study results, the MCR fire risk has decreased by approximately 66%. In general, the MCR fire scenarios cover all fires that occur within the MCR. Also, they include scenarios involving fires in compartments other than the MCR that may force MCR abandonment. In this study, though forced abandonment scenarios caused by an ex-MCR fire were not addressed, their contribution to MCR fire risk is expected to be insignificant. Evaluation of a MCR fire risk was performed using fire simulations, a fire human reliability analysis method, and the IPRO-ZONE. The simulations of the MCR fire were conducted by using the FDS (fire dynamic simulator) to estimate the severity factor (SF) and non-suppression probability (NS) for MCR abandonment fire scenarios. The scoping HRA approach of NUREG-1921 was applied to estimate new human actions related to an MCR fire. The IPRO-ZONE was utilized to construct a one-top fire PSA model and generate the fire-induced equipment failure probability

  20. Numerical simulations of fire spread in a Pinus pinaster needles fuel bed

    International Nuclear Information System (INIS)

    The main aim of this paper is to extend the cases of WFDS model validation by comparing its predictions to literature data on a ground fire spreading in a Pinus pinaster needles fuel bed. This comparison is based on the experimental results of Mendes-Lopes and co-workers. This study is performed using the same domain as in the experiments (3.0m×1.2m×0.9m) with a mesh of 49,280 cells. We investigate the influence of wind (varied between 0 and 2 m/s) and moisture content (10 and 18%) on the rate of spread. The WFDS rate of spread is determined using a cross-correlation function of ground temperature profiles. The simulated rate of spread, as well as temperature, compared favourably to experimental values and show the WFDS model capacity to predict ground fires in Pinus Pinaster fuel beds.

  1. Metallurgical Analysis of Cracks Formed on Coal Fired Boiler Tube

    Science.gov (United States)

    Kishor, Rajat; Kyada, Tushal; Goyal, Rajesh K.; Kathayat, T. S.

    2015-02-01

    Metallurgical failure analysis was carried out for cracks observed on the outer surface of a boiler tube made of ASME SA 210 GR A1 grade steel. The cracks on the surface of the tube were observed after 6 months from the installation in service. A careful visual inspection, chemical analysis, hardness measurement, detailed microstructural analysis using optical and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy were carried out to ascertain the cause for failure. Visual inspection of the failed tube revealed the presence of oxide scales and ash deposits on the surface of the tube exposed to fire. Many cracks extending longitudinally were observed on the surface of the tube. Bulging of the tube was also observed. The results of chemical analysis, hardness values and optical micrographs did not exhibit any abnormality at the region of failure. However, detailed SEM with EDS analysis confirmed the presence of various oxide scales. These scales initiated corrosion at both the inner and outer surfaces of the tube. In addition, excessive hoop stress also developed at the region of failure. It is concluded that the failure of the boiler tube took place owing to the combined effect of the corrosion caused by the oxide scales as well as the excessive hoop stress.

  2. On the characterization of vegetation recovery after fire disturbance using Fisher-Shannon analysis and SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series

    Science.gov (United States)

    Lasaponara, Rosa; Lanorte, Antonio; Lovallo, Michele; Telesca, Luciano

    2015-04-01

    characterize vegetation recovery after fire disturbanceInternational Journal of Applied Earth Observation and Geoinformation 26 441-446 Lanorte A, M Danese, R Lasaponara, B Murgante 2014 Multiscale mapping of burn area and severity using multisensor satellite data and spatial autocorrelation analysis International Journal of Applied Earth Observation and Geoinformation 20, 42-51 Tuia D, F Ratle, R Lasaponara, L Telesca, M Kanevski 2008 Scan statistics analysis of forest fire clusters Communications in Nonlinear Science and Numerical Simulation 13 (8), 1689-1694 Telesca L, R Lasaponara 2006 Pre and post fire behavioral trends revealed in satellite NDVI time series Geophysical Research Letters 33 (14) Lasaponara R 2005 Intercomparison of AVHRR based fire susceptibility indicators for the Mediterranean ecosystems of southern Italy International Journal of Remote Sensing 26 (5), 853-870

  3. Analysis of accelerants and fire debris using aroma detection technology

    Energy Technology Data Exchange (ETDEWEB)

    Barshick, S.A.

    1997-01-17

    The purpose of this work was to investigate the utility of electronic aroma detection technologies for the detection and identification of accelerant residues in suspected arson debris. Through the analysis of known accelerant residues, a trained neural network was developed for classifying suspected arson samples. Three unknown fire debris samples were classified using this neural network. The item corresponding to diesel fuel was correctly identified every time. For the other two items, wide variations in sample concentration and excessive water content, producing high sample humidities, were shown to influence the sensor response. Sorbent sampling prior to aroma detection was demonstrated to reduce these problems and to allow proper neural network classification of the remaining items corresponding to kerosene and gasoline.

  4. Understanding coupled natural and human systems on fire prone landscapes: integrating wildfire simulation into an agent based planning system.

    Science.gov (United States)

    Barros, Ana; Ager, Alan; Preisler, Haiganoush; Day, Michelle; Spies, Tom; Bolte, John

    2015-04-01

    Agent-based models (ABM) allow users to examine the long-term effects of agent decisions in complex systems where multiple agents and processes interact. This framework has potential application to study the dynamics of coupled natural and human systems where multiple stimuli determine trajectories over both space and time. We used Envision, a landscape based ABM, to analyze long-term wildfire dynamics in a heterogeneous, multi-owner landscape in Oregon, USA. Landscape dynamics are affected by land management policies, actors decisions, and autonomous processes such as vegetation succession, wildfire, or at a broader scale, climate change. Key questions include: 1) How are landscape dynamics influenced by policies and institutions, and 2) How do land management policies and actor decisions interact to produce intended and unintended consequences with respect to wildfire on fire-prone landscapes. Applying Envision to address these questions required the development of a wildfire module that could accurately simulate wildfires on the heterogeneous landscapes within the study area in terms of replicating historical fire size distribution, spatial distribution and fire intensity. In this paper we describe the development and testing of a mechanistic fire simulation system within Envision and application of the model on a 3.2 million fire prone landscape in central Oregon USA. The core fire spread equations use the Minimum Travel Time algorithm developed by M Finney. The model operates on a daily time step and uses a fire prediction system based on the relationship between energy release component and historical fires. Specifically, daily wildfire probabilities and sizes are generated from statistical analyses of historical fires in relation to daily ERC values. The MTT was coupled with the vegetation dynamics module in Envision to allow communication between the respective subsystem and effectively model fire effects and vegetation dynamics after a wildfire. Canopy and

  5. Some insights from fire risk analysis of US nuclear power plants

    International Nuclear Information System (INIS)

    Fire risk analysis has been conducted for a significant portion of the nuclear power plants in the U.S. using either Probabilistic Risk Assessments (PRAs) or FIVE or a combination of the two methodologies. Practically all fire risk studies have used step-wise, screening approach. To establish the contents of a compartment, the cable routing information collected for Appendix R compliance have been used in practically all risk studies. In several cases, the analysts have gone beyond the Appendix R and have obtained the routing of additional cables. For fire impact analysis typically an existing PRA model is used. For fire frequencies, typically, a generic data base is used. Fire scenarios are identified in varying levels of detail. The most common approach, in the early stages of screening, is based on the assumption that given a fire, the entire contents of the compartment are lost. Less conservative scenarios are introduced at later stages of the analysis which may include fire propagation patterns, fires localized to an item. and suppression of the fire before critical damage. For fire propagation and damage analysis, a large number of studies have used FIVE and many have used COMPBRN. For detection and suppression analysis, the generic suppression system unavailabilities given in FIVE have been used. The total core damage frequencies typically range between 1x10-6 to 1x10-4 per year. Control rooms and cable spreading rooms are the two most common areas found to be significant contributors to fire risk. Other areas are mainly from the Auxiliary Building (in the case of PWRs) and Reactor Building (in the case of BWRs). Only in one case, the main contributor to fire is the turbine building, which included several safety related equipment and cables. (author)

  6. Modelling of electrical cabinet fires

    International Nuclear Information System (INIS)

    Electrical enclosures are a source of fire in complex analysis by the different nature of the materials which constitute them, various configurations possible physical and the influence of (natural and forced) ventilation system, the study and evolution of the fire in a fuel source of such complexity requires a methodology and tools. Informed by the risk-based performance analyses used, as a complement to the traditional deterministic approach, simulation of fire, among other tools, codes for this purpose.

  7. Stochastic modeling analysis and simulation

    CERN Document Server

    Nelson, Barry L

    1995-01-01

    A coherent introduction to the techniques for modeling dynamic stochastic systems, this volume also offers a guide to the mathematical, numerical, and simulation tools of systems analysis. Suitable for advanced undergraduates and graduate-level industrial engineers and management science majors, it proposes modeling systems in terms of their simulation, regardless of whether simulation is employed for analysis. Beginning with a view of the conditions that permit a mathematical-numerical analysis, the text explores Poisson and renewal processes, Markov chains in discrete and continuous time, se

  8. Semi-parametric analysis of extreme forest fires

    OpenAIRE

    Ramesh, N.I.

    2005-01-01

    Forest fires can cause extensive damage to natural resources and properties. They can also destroy wildlife habitat, affect the forest ecosystem and threaten human lives. In this paper incidences of extreme wildland fires are modelled by a point process model which incorporates time-trend. A model based on a generalised Pareto distribution is used to model data on acres of wildland burnt by extreme fire in the US since 1825. A semi-parametric smoothing approach, which is very useful in explor...

  9. Modelling and Analysis of Forest Fire in Portugal - Part I

    OpenAIRE

    Silva, Giovani Loiola; Dias, Maria Ines; Oliveira, Manuela; Marques, Susete; Borges, Jose

    2012-01-01

    In the last decades forest fires became a serious problem in Portugal due to different issues such a climatic characteristics and nature of Portuguese forest. In order to analyze forest data, we use generalized linear models for modeling the proportion of burned forest area. Our goal is to find out fire risk factors that influence that proportion of burned area and what may make a forest type susceptible or resistant to fire. Then, we analyze forest fire data in Portugal during 1990-1994 thr...

  10. Energy Analysis of a Biomass Co-firing Based Pulverized Coal Power Generation System

    OpenAIRE

    Marc A. Rosen; Shoaib Mehmood; Bale V. Reddy

    2012-01-01

    The results are reported of an energy analysis of a biomass/coal co-firing based power generation system, carried out to investigate the impacts of biomass co-firing on system performance. The power generation system is a typical pulverized coal-fired steam cycle unit, in which four biomass fuels (rice husk, pine sawdust, chicken litter, and refuse derived fuel) and two coals (bituminous coal and lignite) are considered. Key system performance parameters are evaluated for various fuel combina...

  11. Performance Analysis of a Coal-Fired External Combustion Compressed Air Energy Storage System

    Directory of Open Access Journals (Sweden)

    Wenyi Liu

    2014-11-01

    Full Text Available Compressed air energy storage (CAES is one of the large-scale energy storage technologies utilized to provide effective power peak load shaving. In this paper, a coal-fired external combustion CAES, which only uses coal as fuel, is proposed. Unlike the traditional CAES, the combustion chamber is substituted with an external combustion heater in which high-pressure air is heated before entering turbines to expand in the proposed system. A thermodynamic analysis of the proposed CAES is conducted on the basis of the process simulation. The overall efficiency and the efficiency of electricity storage are 48.37% and 81.50%, respectively. Furthermore, the exergy analysis is then derived and forecasted, and the exergy efficiency of the proposed system is 47.22%. The results show that the proposed CAES has more performance advantages than Huntorf CAES (the first CAES plant in the world. Techno-economic analysis of the coal-fired CAES shows that the cost of electricity (COE is $106.33/MWh, which is relatively high in the rapidly developing power market. However, CAES will be more likely to be competitive if the power grid is improved and suitable geographical conditions for storage caverns are satisfied. This research provides a new approach for developing CAES in China.

  12. Safety analysis of the existing 804 and 845 firing facilities

    International Nuclear Information System (INIS)

    A safety analysis was performed to determine if normal operations and/or potential accidents at the 804 and 845 Firing Facilities at Site 300 could present undue hazards to the general public, peronnel at Site 300, or have an adverse effect on the environment. The normal operation and credible accident that might have an effect on these facilities or have off-site consequence were considered. It was determined by this analysis that all but one of the hazards were either low or of the type or magnitude routinely encountered and/or accepted by the public. The exception was explosives. Since this hazard has the potential for causing significant on-site and minimum off-site consequences, Bunkers 804 and 845 have been classified as moderate hazard facilties per DOE Order 5481.1A. This safety analysis concluded that the operation at these facilities will present no undue risk to the health and safety of LLNL employees or the public

  13. Fire Risk Analysis and Optimization of Fire Prevention Management for Green Building Design and High Rise Buildings: Hong Kong Experience

    OpenAIRE

    Yau Albert; Ho Samuel K. M.

    2014-01-01

    There are many iconic high rise buildings in Hong Kong, for example, International Commercial Centre, International Financial Centre, etc. Fire safety issue in high rise buildings has been raised by local fire professionals in terms of occupant evacuation, means of fire-fighting by fire fighters, sprinkler systems to automatically put off fires in buildings, etc. Fire risk becomes an important issue in building fire safety because it relates to life safety of building occupants where they liv...

  14. Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

    International Nuclear Information System (INIS)

    In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide-water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated

  15. Simulation of Intelligent Fire Detection and Alarm System for a W d p .

    OpenAIRE

    V. B. Pati; Joshi, S.P.; R. Sowmianarayanan; M. Vedavath; R.K. Rana

    1989-01-01

    Fire is one of the major hazards in warships. A warship being avery complex structure, with sophisticated weapons, machinery, fueland ammunition is always at risk of fire. Restrictions on movement of ship's personnel and equipment requires automation in fire detectionand control systems. This paper describes the limitations of conventional fire detection systems, followed by the features of modern fire detection and alarnr (the so-called intelligent) systems and thetypes of fire detectors use...

  16. Boreal forest fires in 1997 and 1998: a seasonal comparison using transport model simulations and measurement data

    Directory of Open Access Journals (Sweden)

    N. Spichtinger

    2004-01-01

    Full Text Available Forest fire emissions have a strong impact on the concentrations of trace gases and aerosols in the atmosphere. In order to quantify the influence of boreal forest fire emissions on the atmospheric composition, the fire seasons of 1997 and 1998 are compared in this paper. Fire activity in 1998 was very strong, especially over Canada and Eastern Siberia, whereas it was much weaker in 1997. According to burned area estimates the burning in 1998 was more than six times as intense as in 1997. Based on hot spot locations derived from ATSR (Along Track Scanning Radiometer data and official burned area data, fire emissions were estimated and their transport was simulated with a Lagrangian tracer transport model. Siberian and Canadian forest fire tracers were distinguished to investigate the transport of both separately. The fire emissions were transported even over intercontinental distances. Due to the El Niño induced meteorological situation, transport from Siberia to Canada was enhanced in 1998. Siberian fire emissions were transported towards Canada and contributed concentrations more than twice as high as those due to Canada's own CO emissions by fires. In 1998 both tracers arrive at higher latitudes over Europe, which is due to a higher North Atlantic Oscillation (NAO index in 1998. The simulated emission plumes are compared to CMDL (Climate Monitoring and Diagnostics Laboratory CO2 and CO data, Total Ozone Mapping Spectrometer (TOMS aerosol index (AI data and Global Ozone Monitoring Experiment (GOME tropospheric NO2 and HCHO columns. All the data show clearly enhanced signals during the burning season of 1998 compared to 1997. The results of the model simulation are in good agreement with ground-based as well as satellite-based measurements.

  17. Development of a personal computer code for fire protection analysis of DOE facility air-cleaning systems

    International Nuclear Information System (INIS)

    The United States Department of Energy (DOE) has sponsored development of a computer code to aid analysts performing fire hazards analyses for DOE facilities. The code selected for this application was the FIRAC code developed by the Los Alamos National Laboratory for the Nuclear Regulatory Commission. The original code has been modified by the Westinghouse-Hanford Company. The FIRAC code simulates fire accidents in nuclear facilities and predicts effects of a hypothetical fire within a compartment and its effect throughout the rest of the facility, particularly the air-cleaning systems. The FIRAC code was designed to run on Cray supercomputers. The input format is difficult to use. For this code to be useful to the DOE fire protection community, it had to be converted to run on an IBM PC and couple with a menu-driven pre-processor that would make preparation of the input easy to use for fire protection engineers. In addition, a graphical display of the analysis results was required. In this paper the authors describe the pre-processor, the PC version of FIRAC, and the post-processor graphics package. In the presentation, a demonstration of how to set up a problem and use the code is made. 4 figs

  18. Multicriteria Analysis of Fire Risk in the Split-Dalmatia County

    Directory of Open Access Journals (Sweden)

    Antonija Netolicki

    2012-06-01

    Full Text Available Considering the fact that, in the Split-Dalmatia County, forest fires occur very frequently during the tourist season, causing catastrophic damage to the environment, affecting tourism and other industries, this paper will demonstrate how the use of GIS tools can analyse existing data to assess levels of vulnerability to fire in the county. The data collected that affect the outbreak of open fire include: climate (temperature and relative humidity, topography (aspect, slope of the terrain, vegetation (CORINE Land Cover, NDVI and anthropogenic factors (e.g. roads, railways and settlements. The article shows how ArcInfo GIS software may be used in order to improve preventive measures and operative procedures. These are necessary due to the large numbers of fires that occur in this area during the summer months.Keywords: Split-Dalmatia County; open fire; reclassification of data; fire cause factors; GIS; multicriteria analysis

  19. FIRE DESIGN: DIRECT COMPARISON BETWEEN FIRE CURVES. THE CASE STUDY OF A NURSERY

    Directory of Open Access Journals (Sweden)

    Mara Lombardi

    2013-01-01

    Full Text Available According to fire safety engineering, the present study analyzes fire design settings for simulation of fire in a nursery and proposes to compare simulations developed with a natural fire curve and nominal fire curve. Comparative analysis was developed according to thermo-fluid dynamic parameters that are relevant to the safety of the exposed and for the representative period of the danger flow to the exposed, which are mainly children between 0 and 3 years of age, helpless under ordinary conditions and even more so in case of emergency. Defined conditions of structure and ventilation, Two fire simulations, differentiated by fire curve, have been implemented: First simulation: the parameters have been derived from the simulation of a fire, characterized by analytic function of Heat Release Rate (HRR Second simulation: the HRR function was obtained ex post by making a simulation of natural fire in realistically furnished room by imposing a minimum effective primer. The simulated HRR curve, appropriately linearized, allows to estimate a Likely Fire Curve (LFC. The simulations have been developed for a time of about 15 min, starting from the ignition of fire whereas the flow of the danger is serious for exposed mainly in this first phase of fire. The comparison between the parameters of fire involved the Temperature-Time Curve and HRR-Time Curve of both simulations and the ISO 834 Curve, which is a consolidated benchmark in Fire Safety Engineering (FSE. The nominal curves have been introduced for the purpose of checking whether the structural strength and integrity: the adoption of these curves in the fire safety engineering was made by analogy, on the assumption that the phenomena of major intensity, that these curves represent, ensure a safe approach on the choice of the fire design. The study showed indeed that the analytical curve, adopted in order to verify the structural strength, produces fields of both temperature and toxic concentrations

  20. One-dimensional simulation of fire injection heights in contrasted meteorological scenarios with PRM and Meso-NH models

    Directory of Open Access Journals (Sweden)

    S. Strada

    2013-02-01

    Full Text Available Wild-fires release huge amounts of aerosol and hazardous trace gases in the atmosphere. The residence time and the dispersion of fire pollutants in the atmosphere can range from hours to days and from local to continental scales. These various scenarios highly depend on the injection height of smoke plumes. The altitude at which fire products are injected in the atmosphere is controlled by fire characteristics and meteorological conditions. Injection height however is still poorly accounted in chemistry transport models for which fires are sub-grid scale processes which need to be parametrised. Only recently, physically-based approaches for estimating the fire injection heights have been developed which consider both the convective updrafts induced by the release of fire sensible heat and the impact of background meteorological environment on the fire convection dynamics. In this work, two different models are used to simulate fire injection heights in contrasted meteorological scenarios: a Mediterranean arson fire and two Amazonian deforestation fires. A Eddy-Diffusivity/Mass-Flux approach, formerly developed to reproduce convective boundary layer in the non-hydrostatic meteorological model Meso-NH, is compared to the 1-D Plume Rise Model. For both models, radiosonde data and re-analyses from the European Center for Medium-Range Weather Forecasts (ECMWF have been used as initial conditions to explore the sensitivity of the models responses to different meteorological forcings. The two models predict injection heights for the Mediterranean fire between 1.7 and 3.3 km with the Meso-NH/EDMF model systematically higher than the 1-D PRM model. Both models show a limited sensitivity to the meteorological forcings with a 20–30% difference in the injection height between radiosondes and ECMWF data for this case. Injection heights calculated for the two Amazonian fires ranges from 5 to 6.5 km for the 1-D PRM model and from 2 to 4 km for the Meso

  1. Collection and Analysis of Fire Data at Swedish NPPs

    International Nuclear Information System (INIS)

    The Swedish-Finnish handbook for initiating event frequencies, the I-Book, does not contain any fire frequencies. This matter of fact is not defensible considering the substantial risk contribution caused by fires. In the PSAs performed hitherto the initiating fire frequencies have been determined from case to case. Because data are usually very scarce in these areas it is very important to develop unique definitions, to systematically utilize both international and national experiences and to establish an appropriate statistical estimation method. It is also important to present the accumulated experience such that it can be used for different purposes, not only within PSA but also in the practical fire preventive work. This report describes the data collection scheme, the statistical model and method that have been used in the collection and estimation process. The total population of tires (initiating fires) that have occurred at Swedish and Finnish NPPs is so comprehensive that the estimation of plant specific fire frequencies could be made by using the same Bayesian method that has been used for the determination of component failure frequencies in the Swedish T-Book. When the plant specific frequencies would be partitioned into fire frequencies per compartment or building the statistical material was substantially more meagre. To solve this problem a new methodological development was necessary. The results achieved may, possibly after some modification, be applicable also to other types of system external events

  2. SIMULATION ANALYSIS OF WDM

    Directory of Open Access Journals (Sweden)

    Sanghmitra Yadav

    2015-10-01

    Full Text Available An optical network provides a common infrastructure over which a variety of services can be delivered. These networks are also capable of delivering bandwidth in a flexible manner, supports capacity up gradation and transient nature in data transmission. It consists of optical source (LED, LASER as transmitter and optical fiber as transmission medium with other connectors and photo detector, receiver set. But due to limitation of electronic processing speed, it’s not possible to use all the BW of an optical fiber using a single high capacity channel or wavelength. The primary problem in a WDM network design is to find the best possible path between a source-destination node pair and assign available wavelength to this path for data transmission. To determine the best path a series of measurements are performed which are known as performance matrices. From these performance matrices, the Quality of Service parameters are determined. Here we have designed four different network topologies have been studied and analyzed different number of nodes. We have simulated all these networks with different scenario to obtain the performance matrices. Then we have compared those performance matrices to suggest which network is best under the present case.

  3. Investigation of Lab Fire Prevention Management System of Combining Root Cause Analysis and Analytic Hierarchy Process with Event Tree Analysis

    Directory of Open Access Journals (Sweden)

    Cheng-Chan Shih

    2016-01-01

    Full Text Available This paper proposed a new approach, combining root cause analysis (RCA, analytic hierarchy process (AHP, and event tree analysis (ETA in a loop to systematically evaluate various laboratory safety prevention strategies. First, 139 fire accidents were reviewed to identify the root causes and draw out prevention strategies. Most fires were caused due to runaway reactions, operation error and equipment failure, and flammable material release. These mostly occurred in working places of no prompt fire protection. We also used AHP to evaluate the priority of these strategies and found that chemical fire prevention strategy is the most important control element, and strengthening maintenance and safety inspection intensity is the most important action. Also together with our surveys results, we proposed that equipment design is also critical for fire prevention. Therefore a technical improvement was propounded: installing fire detector, automatic sprinkler, and manual extinguisher in the lab hood as proactive fire protections. ETA was then used as a tool to evaluate laboratory fire risks. The results indicated that the total risk of a fire occurring decreases from 0.0351 to 0.0042 without/with equipment taking actions. Establishing such system can make Environment, Health and Safety (EH&S office not only analyze and prioritize fire prevention policies more practically, but also demonstrate how effective protective equipment improvement can achieve and the probabilities of the initiating event developing into a serious accident or controlled by the existing safety system.

  4. Simulation of the Thermal Behaviour of UF6 Containment Packages in Fires

    International Nuclear Information System (INIS)

    Computer simulation results concerning the thermal behaviour of a UF6 container in fires are presented. The results have been obtained using three different approximations, namely: a coarsely lumped parameter model, a heat conduction model and, finally, a finite element heat conduction model. In all cases, the sinking of the non-melted UF6 core is not considered. Effective parameters for the heat conduction were used to simulate the heat conduction through the melted material. Accordingly, the effects of the natural convection around the non-melted UF6 core are not considered. The results are compared with numerical and experimental data in order to assess the performance of the computational approaches. (author)

  5. Assessment of fire emission inventories during the South American Biomass Burning Analysis (SAMBBA) experiment

    Science.gov (United States)

    Pereira, Gabriel; Siqueira, Ricardo; Rosário, Nilton E.; Longo, Karla L.; Freitas, Saulo R.; Cardozo, Francielle S.; Kaiser, Johannes W.; Wooster, Martin J.

    2016-06-01

    Fires associated with land use and land cover changes release large amounts of aerosols and trace gases into the atmosphere. Although several inventories of biomass burning emissions cover Brazil, there are still considerable uncertainties and differences among them. While most fire emission inventories utilize the parameters of burned area, vegetation fuel load, emission factors, and other parameters to estimate the biomass burned and its associated emissions, several more recent inventories apply an alternative method based on fire radiative power (FRP) observations to estimate the amount of biomass burned and the corresponding emissions of trace gases and aerosols. The Brazilian Biomass Burning Emission Model (3BEM) and the Fire Inventory from NCAR (FINN) are examples of the first, while the Brazilian Biomass Burning Emission Model with FRP assimilation (3BEM_FRP) and the Global Fire Assimilation System (GFAS) are examples of the latter. These four biomass burning emission inventories were used during the South American Biomass Burning Analysis (SAMBBA) field campaign. This paper analyzes and inter-compared them, focusing on eight regions in Brazil and the time period of 1 September-31 October 2012. Aerosol optical thickness (AOT550 nm) derived from measurements made by the Moderate Resolution Imaging Spectroradiometer (MODIS) operating on board the Terra and Aqua satellites is also applied to assess the inventories' consistency. The daily area-averaged pyrogenic carbon monoxide (CO) emission estimates exhibit significant linear correlations (r, p > 0.05 level, Student t test) between 3BEM and FINN and between 3BEM_ FRP and GFAS, with values of 0.86 and 0.85, respectively. These results indicate that emission estimates in this region derived via similar methods tend to agree with one other. However, they differ more from the estimates derived via the alternative approach. The evaluation of MODIS AOT550 nm indicates that model simulation driven by 3BEM and FINN

  6. Meteosat SEVIRI Fire Radiative Power (FRP products from the Land Surface Analysis Satellite Applications Facility (LSA SAF – Part 1: Algorithms, product contents and analysis

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2015-06-01

    information together with the per-pixel uncertainty metrics. Using scene simulations and analysis of real SEVIRI data, including from a period of Meteosat-8 "special operations", we describe some of the sensor and data pre-processing characteristics influencing fire detection and FRP uncertainty. We show that the FTA algorithm is able to discriminate actively burning fires covering down to 10−4 of a pixel, and is more sensitive to fire than algorithms used within many other widely exploited active fire products. We also find that artefacts arising from the digital filtering and geometric resampling strategies used to generate level 1.5 SEVIRI data can significantly increase FRP uncertainties in the SEVIRI active fire products, and recommend that the processing chains used for the forthcoming Meteosat Third Generation attempt to minimise the impact of these types of operations. Finally, we illustrate the information contained within the current Meteosat FRP-PIXEL and FRP-GRID products, providing example analyses for both individual fires and multi-year regional-scale fire activity. A companion paper (Roberts et al., 2015 provides a full product performance evaluation for both products, along with examples of their use for prescribing fire smoke emissions within atmospheric modelling components of the Copernicus Atmosphere Monitoring Service (CAMS.

  7. Process simulation of oxy-fuel combustion for a 300 MW pulverized coal-fired power plant using Aspen Plus

    International Nuclear Information System (INIS)

    Graphical abstract: This paper studied the combustion processes of pulverized coal in a 300 MW power plant using Aspen Plus software. The amount of each component in flue gas in coal-fired processes with air or O2/CO2 as oxidizer was obtained. The differences between the two processes were identified, and the parameter influences of temperature, excess oxygen ratio and molar fraction of O2/CO2 on the proportions of different components in flue gas were examined by sensitivity analysis. - Highlights: • Combustion processes were studied with Aspen Plus for a 300 MW pulverized coal power plant. • The amount of each flue gas component in coal-fired processes with air or O2/CO2 as oxidizer was obtained. • Differences between the two process models were identified. • The influences of operation parameters on the flue gas components were examined. - Abstract: This work focuses on the amounts and components of flue gas for oxy-fuel combustion in a coal-fired power plant (CFPP). The combustion process of pulverized coal in a 300 MW power plant is studied using Aspen Plus software. The amount of each component in flue gas in coal-fired processes with air or O2/CO2 as oxidizer is obtained. The differences between the two processes are identified, and the influences of temperature, excess oxygen ratio and molar fraction of O2/CO2 on the proportions of different components in flue gas are examined by sensitivity analysis. The process simulation results show that replacing atmospheric air by a 21%O2/79%CO2 mixture leads the decrease of the flame temperature from 1789 °C to 1395 °C. The equilibrium amount of NOx declines obviously but the SOx are still at the same level. The mass fraction of CO2 in flue gas increased from 21.3% to 81.5%. The amount of NOx is affected sensitively by the change of temperature and the excess oxygen ratio, but the change of O2/CO2 molar fraction has a little influence to the generation of NOx. With the increasing of O2 concentration, the

  8. Dynamics of firing patterns, synchronization and resonances in neuronal electrical activities: experiments and analysis

    Institute of Scientific and Technical Information of China (English)

    Qishao Lu; Huaguang Gu; Zhuoqin Yang; Xia Shi; Lixia Duan; Yanhong Zheng

    2008-01-01

    Recent advances in the experimental and theore-tical study of dynamics of neuronal electrical firing activi-ties are reviewed. Firstly, some experimental phenomena of neuronal irregular firing patterns, especially chaotic and sto-chastic firing patterns, are presented, and practical nonlinear time analysis methods are introduced to distinguish deter-ministic and stochastic mechanism in time series. Secondly, the dynamics of electrical firing activities in a single neu-ron is concerned, namely, fast-slow dynamics analysis for classification and mechanism of various bursting patterns, one- or two-parameter bifurcation analysis for transitions of firing patterns, and stochastic dynamics of firing activities (stochastic and coherence resonances, integer multiple and other firing patterns induced by noise, etc.). Thirdly, different types of synchronization of coupled neurons with electri-cal and chemical synapses are discussed. As noise and time delay are inevitable in nervous systems, it is found that noise and time delay may induce or enhance synchronization and change firing patterns of coupled neurons. Noise-induced resonance and spatiotemporal patterns in coupled neuronal networks are also demonstrated. Finally, some prospects are presented for future research. In consequence, the idea and methods of nonlinear dynamics are of great significance in exploration of dynamic processes and physiological func-tions of nervous systems.

  9. Feasibility analysis of co-fired combined-cycles using biomass-derived gas and natural gas

    International Nuclear Information System (INIS)

    This paper reports the feasibility analysis of co-fired combined cycles (biomass-derived gas + natural gas) based on the gasification of sugarcane residues (bagasse and trash). Performance results are based on simulation of co-fired combined cycles. Feasibility analysis is based on estimates of the capital costs and O and M costs for such cycles, taking into account current and middle term costs of BIG-CC technology (both considering scaling and learning effects). A deep reduction of the investments regarding the gasification island and auxiliaries is a key point to make BIG-CC competitive in the electricity market, and the required learning can be reached with co-fired BIG-CC systems. Besides alleviation of technical problems related to gas turbine operation with biomass-derived gas, co-fired BIG-CC units can operate with relative flexibility regarding the fuel mix. The construction of 10-15 short- to medium-size gasification islands would be enough to induce important cost reductions due to learning effects. As long as the investment on the gasification island is reduced, and depending on the price ratio of natural gas and biomass, pure BIG-CC plants could achieve a reasonable level of feasibility regarding other options of electricity production. In the short run there is no advantage for co-fired combined cycles regarding the costs of reduction of carbon dioxide emissions, but in the middle run both co-fired and pure BIG-CC power plants can be a better option than capture and storage of CO2

  10. Analysis of biomass co-firing systems in Taiwan power markets using linear complementarity models

    Energy Technology Data Exchange (ETDEWEB)

    Ming-Che Hu; Chun-Hung Lin; Chun-An Chou; Shao-Yiu Hsu; Tzai-Hung Wen [National Taiwan University, Taipei (Taiwan). Department of Bioenvironmental Systems Engineering

    2011-08-15

    Biomass co-firing systems in power plants generate electric power by the simultaneous combustion of biomass and fossil fuels. The co-firing process reduces investment costs by converting biomass energy into electricity in existing conventional power plants. Biomass co-firing significantly reduces carbon dioxide and sulfur dioxide emissions in power generation. To meet the increase in biomass demand, this paper has considered systematic energy crop production, which is expected to increase in the near future. Our aim is to analyze biomass co-firing systems in the Taiwanese electricity market. In this paper, we study two emerging biomass feedstocks: switchgrass and Miscanthus. We focus on the impact of energy crop co-firing on carbon dioxide and sulfur dioxide emissions for electricity generation. A Nash-Cournot competition model, which simulates potential biomass co-firing scenarios, is formulated for power markets. A case study conducted in the Taiwanese electricity market showed that biomass co-firing lowers total electricity demand and sale. Miscanthus is more economical than switchgrass in terms of the production cost and the land required to generate biopower for the same levels of biomass co-firing. 32 refs., 2 figs., 6 tabs.

  11. Engine System Loads Analysis Compared to Hot-Fire Data

    Science.gov (United States)

    Frady, Gregory P.; Jennings, John M.; Mims, Katherine; Brunty, Joseph; Christensen, Eric R.; McConnaughey, Paul R. (Technical Monitor)

    2002-01-01

    Early implementation of structural dynamics finite element analyses for calculation of design loads is considered common design practice for high volume manufacturing industries such as automotive and aeronautical industries. However with the rarity of rocket engine development programs starts, these tools are relatively new to the design of rocket engines. In the NASA MC-1 engine program, the focus was to reduce the cost-to-weight ratio. The techniques for structural dynamics analysis practices, were tailored in this program to meet both production and structural design goals. Perturbation of rocket engine design parameters resulted in a number of MC-1 load cycles necessary to characterize the impact due to mass and stiffness changes. Evolution of loads and load extraction methodologies, parametric considerations and a discussion of load path sensitivities are important during the design and integration of a new engine system. During the final stages of development, it is important to verify the results of an engine system model to determine the validity of the results. During the final stages of the MC-1 program, hot-fire test results were obtained and compared to the structural design loads calculated by the engine system model. These comparisons are presented in this paper.

  12. Fire dynamics during the 20th century simulated by the Community Land Model

    OpenAIRE

    Kloster, S.; N. M. Mahowald; J. T. Randerson; P. E. Thornton; Hoffman, F. M.; Levis, S.; Lawrence, P.J.; Feddema, J. J; Oleson, K. W.; Lawrence, D. M.

    2010-01-01

    Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite-based estimates in terms of magnitude...

  13. Fire dynamics during the 20th century simulated by the Community Land Model

    OpenAIRE

    Kloster, S.; N. M. Mahowald; J. T. Randerson; P. E. Thornton; Hoffman, F. M.; Levis, S.; Lawrence, P.J.; Feddema, J. J; Oleson, K. W.; Lawrence, D. M.

    2010-01-01

    Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite-based estimates in...

  14. Hydrocarbon characterization experiments in fully turbulent fires : results and data analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Suo-Anttila, Jill Marie; Blanchat, Thomas K.

    2011-03-01

    As the capabilities of numerical simulations increase, decision makers are increasingly relying upon simulations rather than experiments to assess risks across a wide variety of accident scenarios including fires. There are still, however, many aspects of fires that are either not well understood or are difficult to treat from first principles due to the computational expense. For a simulation to be truly predictive and to provide decision makers with information which can be reliably used for risk assessment the remaining physical processes must be studied and suitable models developed for the effects of the physics. The model for the fuel evaporation rate in a liquid fuel pool fire is significant because in well-ventilated fires the evaporation rate largely controls the total heat release rate from the fire. This report describes a set of fuel regression rates experiments to provide data for the development and validation of models. The experiments were performed with fires in the fully turbulent scale range (> 1 m diameter) and with a number of hydrocarbon fuels ranging from lightly sooting to heavily sooting. The importance of spectral absorption in the liquid fuels and the vapor dome above the pool was investigated and the total heat flux to the pool surface was measured. The importance of convection within the liquid fuel was assessed by restricting large scale liquid motion in some tests. These data sets provide a sound, experimentally proven basis for assessing how much of the liquid fuel needs to be modeled to enable a predictive simulation of a fuel fire given the couplings between evaporation of fuel from the pool and the heat release from the fire which drives the evaporation.

  15. Raman spectroscopy in the analysis of fire gases

    OpenAIRE

    Aldén, M.; Blomqvist, J.; Edner, H; Lundberg, H

    1983-01-01

    Raman scattering is a possible technique for analysing gas mixtures. In the work here described Raman scattering was used for detection of gases extracted from different model fires, where wood, polymethylmetachrylate (PMMA) and polystyrene were used as test materials. Raman spectra of gas samples from differently ventilated model fires are presented as well as the variation of O2, CO2 and CO concentrations as a function of time with an effective time constant of less than 5 s. The sensitivit...

  16. Qualitative Analysis Results for Applications of a New Fire Probabilistic Safety Assessment Method to Ulchin Unit 3

    International Nuclear Information System (INIS)

    The fire PRA Implementation Guide has been used for performing a fire PSA for NPPs in Korea. Recently, US NRC and EPRI developed a new fire PSA method, NUREG/CR-6850, to provide state-of-the-art methods, tools, and data for the conduct of a fire PSA for a commercial nuclear power plant (NPP). Due to the limited budget and man powers for the development of KSRP, hybrid PSA approaches, using NUREG/CR-6850 and Fire PRA Implementation Guide, will be employed for conducting a fire PSA of Ulchin Unit 3. In this paper, the qualitative analysis results for applications of a new fire PSA method to Ulchin Unit 3 are presented. This paper introduces the qualitative analysis results for applications of a new fire PSA method to Ulchin Unit 3. Compared with the previous industry, the number of fire areas for quantification identified and the number of equipment selected has increased

  17. Research on solar aided coal-fired power generation system and performance analysis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Integrating solar power utilization systems with coal-fired power units, the solar aided coal-fired power generation (SACPG) shows a significant prospect for the large-scale utilization of solar energy and energy saving of thermal power units. The methods and mechanism of system integration were studied. The parabolic trough solar collectors were used to collect solar energy and the integration scheme of SACPG system was determined considering the matching of working fluid flows and energy flows. The thermodynamic characteristics of solar thermal power generation and their effects on the performance of thermal power units were studied, and based on this the integration and optimization model of system structure and parameters were built up. The integration rules and coupling mecha- nism of SACPG systems were summarized in accordance with simulation results. The economic analysis of this SACPG system showed that the solar LEC of a typical SACPG system, considering CO2 avoidance, is 0.098 $/kW·h, lower than that of SEGS, 0.14 $/kW·h.

  18. CAFE: A Computer Tool for Accurate Simulation of the Regulatory Pool Fire Environment for Type B Packages

    International Nuclear Information System (INIS)

    The Container Analysis Fire Environment computer code (CAFE) is intended to provide Type B package designers with an enhanced engulfing fire boundary condition when combined with the PATRAN/P-Thermal commercial code. Historically an engulfing fire boundary condition has been modeled as σT4 where σ is the Stefan-Boltzman constant, and T is the fire temperature. The CAFE code includes the necessary chemistry, thermal radiation, and fluid mechanics to model an engulfing fire. Effects included are the local cooling of gases that form a protective boundary layer that reduces the incoming radiant heat flux to values lower than expected from a simple σT4 model. In addition, the effect of object shape on mixing that may increase the local fire temperature is included. Both high and low temperature regions that depend upon the local availability of oxygen are also calculated. Thus the competing effects that can both increase and decrease the local values of radiant heat flux are included in a reamer that is not predictable a-priori. The CAFE package consists of a group of computer subroutines that can be linked to workstation-based thermal analysis codes in order to predict package performance during regulatory and other accident fire scenarios

  19. Simulations of microphysical, radiative, and dynamical processes in a continental-scale forest fire smoke plume

    Science.gov (United States)

    Westphal, Douglas L.; Toon, Owen B.

    1991-01-01

    The impact of a large forest fire smoke plume on atmospheric processes is studied through a numerical model of meteorology, aerosols, and radiative transfer. The simulated smoke optical depths at 0.63-micron wavelength are in agreement with analyses of satellite data and show values as high as 1.8. The smoke has an albedo of 35 percent, or more than double the clear-sky value, and cools the surface by as much as 5 K. An imaginary refractive index, n sub im, of 0.01 yields results which closely match the observed cooling, single scattering albedo, and the Angstrom wavelength exponent. An n exp im of 0.1, typical of smoke from urban fires, produces 9 K cooling. Coagulation causes the geometric mean radius by number to increase from the initial value of 0.08 micron to a final value of 0.15 micron, while the specific extinction and absorption increase by 40 and 25 percent, respectively.

  20. Crown Fire Potential

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Crown fire potential was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The...

  1. Fire activity inside and outside protected areas in Sub-Saharan Africa: a continental analysis of fire and its implications for biodiversity and management

    Science.gov (United States)

    Palumbo, Ilaria; Gregoire, Jean-Marie; Simonetti, Dario; Punga, Mihkel; Dubois, Gregoire

    2010-05-01

    around each of them. The region outside the protected areas was used for comparison in order to identify differences or similarities between their fire activities. This also contributed to understand how management and conservation influence fire and assess the level of isolation of the protected areas. The long time series allowed the identification of trends and the interannual variability in the fire activity. The dry season length was determined using FEWS RFE rainfall data (implemented at NOAA's Climate Prediction Center). Within each dry season we identified three periods (early, middle and late) in order to characterize the climatic and environmental conditions at which fires occur and identify trends and patterns. Every period of the dry season lasts two months and shows different conditions of temperature and drought level. Fire activity was characterized combining the information on active fires and burned areas. For each year we determined the fire seasonality, the fire frequency, the main vegetation types affected, the extent and intensity of burning. This information was also used to distinguish management fires from those related to other human activities like transhumance, agriculture and poaching in order to identify possible sources of threat to the protected areas. Information on the road network, the location of villages and cultivated fields were also included. Future work will include a combined analysis of fire activity and land-cover, land-cover change information so that management plans adopted in protected areas can be evaluated in their effectiveness to promote biodiversity and nature conservation.

  2. Fire activity inside and outside protected areas in Sub-Saharan Africa: a continental analysis of fire and its implications for biodiversity and land management

    Science.gov (United States)

    Palumbo, Ilaria; Gregoire, Jean-Marie; Simonetti, Dario; Punga, Mihkel; Dubois, Gregoire

    2010-05-01

    around each of them. The region outside the protected areas was used for comparison in order to identify differences or similarities between their fire activities. This also contributed to understand how management and conservation influence fire and assess the level of isolation of the protected areas. The long time series allowed the identification of trends and the interannual variability of the fire activity. The dry season length was determined using FEWS RFE rainfall data (implemented at NOAA's Climate Prediction Center). Within each dry season we identified three periods (early, middle and late) in order to characterize the climatic and environmental conditions at which fires occur and identify trends and patterns. Every period of the dry season lasts two months and shows different conditions of temperature and drought level. Fire activity was characterized combining the information on active fires and burned areas. For each year we determined the fire seasonality, the fire frequency, the main vegetation types affected, the extent and intensity of burning. This information was also used to distinguish management fires from those related to other human activities like transhumance, agriculture and poaching in order to identify possible sources of threat to the protected areas. Information on the road network, the location of villages and cultivated fields were also included. Future work will include a combined analysis of fire activity and land-cover, land-cover change information so that management plans adopted in protected areas can be evaluated in their effectiveness to promote biodiversity and nature conservation.

  3. Simulating boreal forest carbon dynamics after stand-replacing fire disturbance: insights from a global process-based vegetation model

    Science.gov (United States)

    Yue, C.; Ciais, P.; Luyssaert, S.; Cadule, P.; Harden, J.; Randerson, J.; Bellassen, V.; Wang, T.; Piao, S.L.; Poulter, B.; Viovy, N.

    2013-01-01

    Stand-replacing fires are the dominant fire type in North American boreal forests. They leave a historical legacy of a mosaic landscape of different aged forest cohorts. This forest age dynamics must be included in vegetation models to accurately quantify the role of fire in the historical and current regional forest carbon balance. The present study adapted the global process-based vegetation model ORCHIDEE to simulate the CO2 emissions from boreal forest fire and the subsequent recovery after a stand-replacing fire; the model represents postfire new cohort establishment, forest stand structure and the self-thinning process. Simulation results are evaluated against observations of three clusters of postfire forest chronosequences in Canada and Alaska. The variables evaluated include: fire carbon emissions, CO2 fluxes (gross primary production, total ecosystem respiration and net ecosystem exchange), leaf area index, and biometric measurements (aboveground biomass carbon, forest floor carbon, woody debris carbon, stand individual density, stand basal area, and mean diameter at breast height). When forced by local climate and the atmospheric CO2 history at each chronosequence site, the model simulations generally match the observed CO2 fluxes and carbon stock data well, with model-measurement mean square root of deviation comparable with the measurement accuracy (for CO2 flux ~100 g C m−2 yr−1, for biomass carbon ~1000 g C m−2 and for soil carbon ~2000 g C m−2). We find that the current postfire forest carbon sink at the evaluation sites, as observed by chronosequence methods, is mainly due to a combination of historical CO2 increase and forest succession. Climate change and variability during this period offsets some of these expected carbon gains. The negative impacts of climate were a likely consequence of increasing water stress caused by significant temperature increases that were not matched by concurrent increases in precipitation. Our simulation

  4. A probabilistic fire hazard analysis of power cable routes to shutdown equipment

    International Nuclear Information System (INIS)

    Operational experience has demonstrated the need to reevaluate the use of concepts applied to the nuclear industry such as the defense in depth related to protection against fires. This concept states that none of the protection levels against fire should be considered perfect or complete and that each should reach minimum requirements. Among these latter, it stands out fire hazard analysis, which qualifies areas of fire protection, determines its consequences and specifies prevention and detection measures. As a result of the analysis, specific standards establish that power cables of redundant systems should be physically separated, thus avoiding the possibility of loss of these systems in the case of a compartment fire. This paper presents a discussion of the difficulties found in the implementation of deterministic fire hazard program requirements in the routes of power cables necessary for a safe reactor shutdown, and also a probabilistic model to quantify the frequency associated with the routes of power cables in the occurrence of compartment fires when a probabilistic safety assessment is not available. The main of this analysis is to reduce the conservatism of safety regulations. (author)

  5. Analysis of the Schiphol Cell Complex fire using a Bayesian belief net based model

    International Nuclear Information System (INIS)

    In the night of the 26 and 27 October 2005, a fire broke out in the K-Wing of the Schiphol Cell Complex near Amsterdam. Eleven of 43 occupants of this wing died due to smoke inhalation. The Dutch Safety Board analysed the fire and released a report 1 year later. This article presents how a probabilistic model based on Bayesian networks can be used to analyse such a fire. The paper emphasises the usefulness of the model for this analysis. In additional it discusses the applicability for prioritisation of the recommendations such as those posed by the investigation board for the improvements of fire safety in special buildings. The big advantage of the model is that it can be used not only for fire analyses after accidents, but also prior to the accident, for example in the design phase of the building, to estimate the outcome of a possible fire given different possible scenarios. This contribution shows that if such a model was used before the fire occurred the number of fatalities would have not come as a surprise, since the model predicts a larger percentage of people dying than happened in the real fire.

  6. Using Computational Fluid Dynamics in the forensic analysis of a prison fire.

    Science.gov (United States)

    Jahn, Wolfram; Gonzalez, Orelvis; de Dios Rivera, Juan; Torero, José Luis

    2015-08-01

    On the 8th of December of 2010 a fire killed 81 inmates in a Chilean prison. While the collected evidence (including eye witness' accounts) indicated an intentional fire, started by a group of inmates who were fighting against another group and who ignited a mattress and threw it over a bunk bed inside the cell, it could not be established how fast the fire grew and whether the prison guards acted promptly enough to prevent the tragedy. In this context, the public defender office in charge of the case requested an independent investigation in order to determine the approximated time the fire started, and the temperature evolution of the padlocks at the cell doors during the initial stage, based on the construction characteristics of the prison, the existing materials and the evidence collected during the investigation. Computational Fluid Dynamics (CFD) were used to analyse the movement of the smoke and to match the first appearance of smoke on CCTV recordings at locations away from the fire, allowing for the estimation of the time-line of events. The padlock temperatures as a result of hot gases from the fire was also simulated. It was shown that the fire grew quickly and became uncontrollable before the guards could intervene. By the time the guards arrived at the cells' door, the padlocks were shown to be too hot to be handled without protection. PMID:26126497

  7. Numerical simulation of NOx formation in a cyclone-opposed coal-fired utility boiler

    Institute of Scientific and Technical Information of China (English)

    LI Fang-qin; REN Jian-xing; WEI Dun-song

    2005-01-01

    In this paper, FLUENT software was used to simulate the burning process in a utility boiler. Chose the kinetics/diffusion-limited as combustion model, two-compet-ingrates as devolatjlization model, RNG k-εmodel as viscous model, and PDF model as combustion turbulent flow model. Numerical calculation of NOx formation in a 330 MW cyclone-opposed coal-fired utility boiler with 32 double air registers was done. The distribution characteristics of temperature, NOx and oxygen concentration in furnace were studied. They were symmetrically distributed in furnace. In the combustion area, temperature and NOx concentration are high, while oxygen concentration is low. Temperature and NOx concentration are declined gradually along with furnace height, while oxygen concentration is raised. The higher the temperature is and the greater the excess air coefficient is, the more NOx formation.

  8. High Temperature Corrosion under Laboratory Conditions Simulating Biomass-Firing: A Comprehensive Characterization of Corrosion Products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming;

    2014-01-01

    An austenitic stainless steel (TP 347H FG) was coated with a synthetic deposit and exposed, under laboratory conditions simulating straw-firing at 560 oC, for one week. Microscopic, diffraction and spectroscopic techniques were employed for cross-sectional and plan view ‘top-down’ microstructural...... characterization of the corrosion products. The corrosion products consisted of three layers: i) the outermost layer consisting of a mixed layer of K2SO4 and FexOy on a partly molten layer of the initial deposit, ii) the middle layer consists of spinel (FeCr2O4) and Fe2O3, and iii) the innermost layer is a sponge......-like Ni3S2 containing layer. At the corrosion front, Cl-rich protrusions were observed. Results indicate that selective corrosion of Fe and Cr by Cl, active oxidation and sulphidation attack of Ni are possible corrosion mechanisms....

  9. Accurate Assessment of RSET for Building Fire Based on Engineering Calculation and Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Yan Zhenzhen

    2016-01-01

    Full Text Available In order to obtain the Required Safety Egress Time (RSET accurately, traditional engineering calculation method of evacuation time has been optimized in this paper. Several principles and fact situations were used to optimize the method, such as detecting principle of the fire detecting system, reaction characteristics of staff being in urgent situation, evacuating queuing theory, building structure and the plugging at the porthole. Taking a three-storey KTV as an example, two methods are used to illustrate the reliability and scientific reasonability of the calculation result. The result is deduced by comparing the error (less than 2% at an allowable range between two results. One result is calculated by a modified method of engineering calculation method, and the other one is given based on a Steering model of Pathfinder evacuation simulation software. The optimized RSET has a good feasibility and Accuracy.

  10. The Externally Fired Gas Turbine (EFGT-Cycle) and Simulation of the Key Components

    Energy Technology Data Exchange (ETDEWEB)

    Kautz, Martin Jorge M.G.; Hansen, Ulf [University of Rostock, Institute for Energy and Environmental Technology, Rostock (Germany)

    2002-07-01

    The externally fired gas turbine unites two advantages. On the one hand, the utilisation of the waste heat from the turbine in a recuperative process and, on the other, the possibility to burn 'dirty' fuel. In particular, the EFGT opens a new option to utilise biomass for combined-heat-and-power and contributes to reduce greenhouse gas emissions. A micro gas turbine with 100 kW electric output is chosen as an example to study the effects of temperature difference and pressure loss in the gas-to-air heat exchanger on cycle efficiency and power. The simulation calculations are performed with the codes AspenPlus and GateCycle. In addition to cycle optimisation the effect of low-calorific biogas on the combustion air ratio and the possibility of solar energy as a heat source for the EFGT are studied.

  11. Two-dimensional simulations of possible mesoscale effects of nuclear war fires 1. Model description

    International Nuclear Information System (INIS)

    In this paper and the companion paper by Giorgi and Visconti [this issue] a two-dimensional mesoscale meteorological model is coupled to an aerosol model to investigate possible mesoscale effects of nuclear war fires. The meteorological model used in this study is a two-dimensional analog of the Penn State/NCAR mesoscale model with enhancements in the areas of radiative transfer, surface physics, and moisture physics. The aerosol model solves equations for the hygroscopic and hydrophobic fractions of particulate material and includes particle transport, sedimentation, dry-deposition, in-cloud and below-cloud scavenging, and a first order term accounting for aerosol aging. In this paper the meteorological model and the aerosol model are first described and then applied, as an illustrative example, to a simulation of the development of sea-breezelike circulations induced by contrasts in soil moisture available for evaporation. copyright American Geophysical Union 1989

  12. Sensitivity Analysis of a Simplified Fire Dynamic Model

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Nielsen, Anker

    2015-01-01

    the variation of a single parameter is found to have a major impact on fire safety, it may be necessary to conservatively select this parameter in order to incorporate additional safety. We compare fire scenarios in rooms surrounded by lightweight as well as heavy walls in order to investigate which...... opening, which explains 96% of the uncertainty. After thermal penetration, the energy release rate is still the most important parameter, but now only explains 49% of the variation. The second parameter is the thickness of the surface material, which explains 43%....

  13. Root-cause analysis of burner tip failures in coal-fired power plants

    International Nuclear Information System (INIS)

    Warpage and complete or partial tear of burner material was frequently experienced in coal-fired power plants due to material overheating. Root-cause analysis of a burner tip failure is investigated employing stress modeling in the burner tip material in this study. The analyses performed in this research paper include heat transfer and stress analyses employing computational tools. Thermal analysis was performed using Computational Fluid Dynamics (CFD) software FLUENT for computing temperature distribution within the burner tip due to convection and radiation. Once the temperature distribution in the burner tip is determined, Finite Element Analysis (FEA) is employed using ANSYS to determine the maximum stress and deformations in burner tip material. Both FLUENT and ANSYS are numerical commercial simulation tools employed in this study. Large temperature gradients along the burner tip result in local bending stresses. These stresses resulting in creep stresses might be causing warpage in the burner tip. In this study, a design option was exercised to eliminate the excessive stress gradient in the burner tip material. Seven different FEA models were developed to simulate different operating conditions. Proposed design modification (Model 5) was able to reduce the maximum compressive stress from 76.09 MPa to 33.59 MPa. Significant reduction in the thermal stress due to design modification in Model 5 made author believe that the proposed design solution would eliminate the burner tip failures in this particular power plant. - Highlights: • Maximum stress and displacement values in the baseline model were computed. • Computations were performed using commercial FEA software ANSYS. • Different operating conditions were simulated in models 1-2-3-4. • Proposed geometry to prevent the failure is simulated in Models 5 and 6. • The proposed design solution reduced the maximum compressive stresses by ∼50%

  14. Safety analysis of solvent fire accidents in a fuel reprocessing plant

    International Nuclear Information System (INIS)

    For analyzing the safety evaluation of solvent fire as DBA in an extraction process of nuclear fuel reprocessing plant, computer code named FACE was developed in JAERI under the auspices of the Science and Technology Agency of Japan. The code FACE can provide not only for calculations of temperature, pressure, flow rate and pressure drop in cells and ducts of the network in air-ventilation system by one- and two-dimensional analyses and smoke containing radioactive materials by burning solvent in the network but also for solvent fire behavior in the cell, transport of radioactive materials and its deposition in the network, integrity of HEPA filters, and release of radioactive materials to the environment. Calculations by FACE were compared with data obtained by large-scale demonstration tests in JAERI simulating solvent fire in the extraction process to verify mathematical modeling of the fire accident in the code. (author)

  15. Fire-Needle Moxibustion for the Treatment of Knee Osteoarthritis: A Meta-Analysis.

    Science.gov (United States)

    Wang, Yidan; Xie, Xiaohua; Zhu, Xiaoyue; Chu, Minjie; Lu, Yihua; Tian, Tian; Zhuang, Xun; Jiang, Liying

    2016-01-01

    Objectives. The aim of this study was to evaluate the effectiveness of fire-needle moxibustion as an intervention in the treatment of knee osteoarthritis (KOA). Methods. An updated meta-analysis of randomized controlled trials (RCTs) on fire-needle moxibustion in treating KOA was conducted by searching PubMed, Embase, the Cochrane Library, Web of Science, Wanfang database, and the Chinese Medical Database (CNKI) since their inception through March 2016. The meta-analysis was performed using RevMan 5.3. Results. Thirteen RCTs were identified in the systematic study which consisted of 1179 participants. Fire-needle moxibustion treatment group had a statistical significance on recovery rate as well as recovery and marked-improvement rate compared with control group. Subgroup analysis indicated that there was significant difference between fire-needle moxibustion group and control group. However, GRADE analysis indicated that the quality of evidence for all outcomes was relatively low. Only two of 13 studies reported adverse reactions (difficulty in movement and intolerance of cold). Conclusion. This meta-analysis suggests that fire-needle moxibustion is more effective than control group in symptom management of KOA. Further high quality trials should be conducted to evaluate the effectiveness of fire-needle moxibustion on KOA. PMID:27403195

  16. Fire-Needle Moxibustion for the Treatment of Knee Osteoarthritis: A Meta-Analysis

    Science.gov (United States)

    Wang, Yidan; Xie, Xiaohua; Zhu, Xiaoyue; Chu, Minjie; Lu, Yihua; Tian, Tian

    2016-01-01

    Objectives. The aim of this study was to evaluate the effectiveness of fire-needle moxibustion as an intervention in the treatment of knee osteoarthritis (KOA). Methods. An updated meta-analysis of randomized controlled trials (RCTs) on fire-needle moxibustion in treating KOA was conducted by searching PubMed, Embase, the Cochrane Library, Web of Science, Wanfang database, and the Chinese Medical Database (CNKI) since their inception through March 2016. The meta-analysis was performed using RevMan 5.3. Results. Thirteen RCTs were identified in the systematic study which consisted of 1179 participants. Fire-needle moxibustion treatment group had a statistical significance on recovery rate as well as recovery and marked-improvement rate compared with control group. Subgroup analysis indicated that there was significant difference between fire-needle moxibustion group and control group. However, GRADE analysis indicated that the quality of evidence for all outcomes was relatively low. Only two of 13 studies reported adverse reactions (difficulty in movement and intolerance of cold). Conclusion. This meta-analysis suggests that fire-needle moxibustion is more effective than control group in symptom management of KOA. Further high quality trials should be conducted to evaluate the effectiveness of fire-needle moxibustion on KOA. PMID:27403195

  17. Identifying the location of fire refuges in wet forest ecosystems.

    Science.gov (United States)

    Berry, Laurence E; Driscoll, Don A; Stein, John A; Blanchard, Wade; Banks, Sam C; Bradstock, Ross A; Lindenmayer, David B

    2015-12-01

    The increasing frequency of large, high-severity fires threatens the survival of old-growth specialist fauna in fire-prone forests. Within topographically diverse montane forests, areas that experience less severe or fewer fires compared with those prevailing in the landscape may present unique resource opportunities enabling old-growth specialist fauna to survive. Statistical landscape models that identify the extent and distribution of potential fire refuges may assist land managers to incorporate these areas into relevant biodiversity conservation strategies. We used a case study in an Australian wet montane forest to establish how predictive fire simulation models can be interpreted as management tools to identify potential fire refuges. We examined the relationship between the probability of fire refuge occurrence as predicted by an existing fire refuge model and fire severity experienced during a large wildfire. We also examined the extent to which local fire severity was influenced by fire severity in the surrounding landscape. We used a combination of statistical approaches, including generalized linear modeling, variogram analysis, and receiver operating characteristics and area under the curve analysis (ROC AUC). We found that the amount of unburned habitat and the factors influencing the retention and location of fire refuges varied with fire conditions. Under extreme fire conditions, the distribution of fire refuges was limited to only extremely sheltered, fire-resistant regions of the landscape. During extreme fire conditions, fire severity patterns were largely determined by stochastic factors that could not be predicted by the model. When fire conditions were moderate, physical landscape properties appeared to mediate fire severity distribution. Our study demonstrates that land managers can employ predictive landscape fire models to identify the broader climatic and spatial domain within which fire refuges are likely to be present. It is essential

  18. Analysis of In Mine Acoustic Recordings for Single Fired Explosions

    Science.gov (United States)

    McKenna, S.; Hayward, C.; Stump, B.

    2003-12-01

    In August of 2003, a series of single fired test shots were executed at a copper mine in Arizona. The ten shots, fired on August 18 and 19, 2003, ranged in size from 1700 lbs to 13600 lbs in simultaneously detonated patterns ranging from a single hole to eight holes. All were located within the same pit and within 100 m of each other. Both free face and bench shots were included. Southern Methodist University had previously deployed a set of acoustic gauges ringing the active production areas of the mine. The five Validyne DP250 sensors recorded not only the ten test shots, but also seven delay fired production shots over the four day period from August 18 to 21, 2003. Each recorded blast arrival was analyzed for peak amplitude and spectrum. Signals were then compared for the variability between shots and sensors as well as a comparison between fully contained and poorly contained shots. Blast yield, scale depth, and centroid depth were compared to the above measured quantities for each of the single-fired and production shots.

  19. Analysis of marine stratocumulus clearing events during FIRE

    Science.gov (United States)

    Kloesel, Kevin A.

    1990-01-01

    During FIRE, three major stratocumulus clearing events took place over the project region. These clearing events are analyzed using synoptic variables to determine if these clearing events can be predicted by current modeling techniques. A preliminary statistical evaluation of the correlation between satellite cloud brightness parameters and NMC global model parameters is available in Wylie, et al., 1989.

  20. Technology for analysis of sodium pool fire characteristics

    International Nuclear Information System (INIS)

    Basic and detail design for medium sodium fire test facility was carried out and medium sodium fire test facility was constructed. Design data is as follows. - Test cell material : Concrete with high strength - Test cell dimension ; 48m3 (3x4x4m) - Design temp. ; 700 deg C - Operation temp. ; 530 deg C - Design pressure ; 1 bar (max.) - Dimension(Inside) : 3 x 4 x 4(m) - Test cell thickness ; 45cm - Liner plate with (Thickness : 3mm) In this study, sodium fire characteristics was analyzed and data for validation of computer code was produced. Oxygen and sodium filled in pool pan didn't burns instantly, but pool fire occurred through pre-ignition. Distribution of temperature in test cell was divided by two parts, and temperature at upper position appeared to be higher than temperature at lower position. The temperature in test cell increased with the feed of sodium. The pressure in test cell increased with the feed of sodium. When the feed of sodium was 8kg, peak pressure was 0.075 bar. Peak temperature in sodium pool appeared to be 854 deg C regardless of the feed of sodium. Decrease of 1% in oxygen concentration showed the rise of 0.036bar in pressure

  1. Fire Hazard Analysis for the Cold Vacuum Drying facility (CVD) Facility

    International Nuclear Information System (INIS)

    The CVDF is a nonreactor nuclear facility that will process the Spent Nuclear Fuels (SNF) presently stored in the 105-KE and 105-KW SNF storage basins. Multi-canister overpacks (MCOs) will be loaded (filled) with K Basin fuel transported to the CVDF. The MCOs will be processed at the CVDF to remove free water from the fuel cells (packages). Following processing at the CVDF, the MCOs will be transported to the CSB for interim storage until a long-term storage solution can be implemented. This operation is expected to start in November 2000. A Fire Hazard Analysis (FHA) is required for all new facilities and all nonreactor nuclear facilities, in accordance with U.S. Department of Energy (DOE) Order 5480.7A, Fire Protection. This FHA has been prepared in accordance with DOE 5480.7A and HNF-PRO-350, Fire Hazard Analysis Requirements. Additionally, requirements or criteria contained in DOE, Richland Operations Office (RL) RL Implementing Directive (RLID) 5480.7, Fire Protection, or other DOE documentation are cited, as applicable. This FHA comprehensively assesses the risk of fire at the CVDF to ascertain whether the specific objectives of DOE 5480.7A are met. These specific fire protection objectives are: (1) Minimize the potential for the occurrence of a fire. (2) Ensure that fire does not cause an onsite or offsite release of radiological and other hazardous material that will threaten the public health and safety or the environment. (3) Establish requirements that will provide an acceptable degree of life safety to DOE and contractor personnel and ensure that there are no undue hazards to the public from fire and its effects in DOE facilities. (4) Ensure that vital DOE programs will not suffer unacceptable delays as a result of fire and related perils. (5) Ensure that property damage from fire and related perils does not exceed an acceptable level. (6) Ensure that process control and safety systems are not damaged by fire or related perils. This FHA is based on the

  2. Fire Hazard Analysis for the Cold Vacuum Drying facility (CVD) Facility

    Energy Technology Data Exchange (ETDEWEB)

    SINGH, G.

    2000-09-06

    The CVDF is a nonreactor nuclear facility that will process the Spent Nuclear Fuels (SNF) presently stored in the 105-KE and 105-KW SNF storage basins. Multi-canister overpacks (MCOs) will be loaded (filled) with K Basin fuel transported to the CVDF. The MCOs will be processed at the CVDF to remove free water from the fuel cells (packages). Following processing at the CVDF, the MCOs will be transported to the CSB for interim storage until a long-term storage solution can be implemented. This operation is expected to start in November 2000. A Fire Hazard Analysis (FHA) is required for all new facilities and all nonreactor nuclear facilities, in accordance with U.S. Department of Energy (DOE) Order 5480.7A, Fire Protection. This FHA has been prepared in accordance with DOE 5480.7A and HNF-PRO-350, Fire Hazard Analysis Requirements. Additionally, requirements or criteria contained in DOE, Richland Operations Office (RL) RL Implementing Directive (RLID) 5480.7, Fire Protection, or other DOE documentation are cited, as applicable. This FHA comprehensively assesses the risk of fire at the CVDF to ascertain whether the specific objectives of DOE 5480.7A are met. These specific fire protection objectives are: (1) Minimize the potential for the occurrence of a fire. (2) Ensure that fire does not cause an onsite or offsite release of radiological and other hazardous material that will threaten the public health and safety or the environment. (3) Establish requirements that will provide an acceptable degree of life safety to DOE and contractor personnel and ensure that there are no undue hazards to the public from fire and its effects in DOE facilities. (4) Ensure that vital DOE programs will not suffer unacceptable delays as a result of fire and related perils. (5) Ensure that property damage from fire and related perils does not exceed an acceptable level. (6) Ensure that process control and safety systems are not damaged by fire or related perils. This FHA is based on the

  3. Global fire activity patterns (1996?2006) and climatic influence: an analysis using the World Fire Atlas

    OpenAIRE

    Page, Y.; J. M. C. Pereira; Trigo, R.; Camara, C.; Oom, D.; Mota, B.

    2007-01-01

    Vegetation fires have been acknowledged as an environmental process of global scale, which affects the chemical composition of the troposphere, and has profound ecological and climatic impacts. However, considerable uncertainty remains, especially concerning intra and inter-annual variability of fire incidence. The main goals of our global-scale study were to characterise spatial-temporal patterns of fire activity, to identify broad geographical areas with similar vegetation fire dynamics, an...

  4. FASA – Fire Airborne Spectral Analysis of natural disasters

    OpenAIRE

    F. Schrandt; D. Oertel; Amici, S.; Distefano, G.; Buongiorno, M. F.; P. Haschberger; V. Tank; Kick, H.; E. Lindermeir; W. Skrbek

    2006-01-01

    At present the authors are developing the system FASA, an airborne combination of a Fourier Transform Spectrometer and an imaging system. The aim is to provide a system that is usable to investigate and monitor emissions from natural disasters such as wild fires and from volcanoes. Besides temperatures and (burned) areas FASA will also provide concentration profiles of the gaseous combustion products. These data are needed to improve the knowledge of the effects of such emissions on the globa...

  5. Analysis of fire and smoke threat to off-gas HEPA filters in a transuranium processing plant

    International Nuclear Information System (INIS)

    The author performed an analysis of fire risk to the high-efficiency particulate air (HEPA) filters that provide ventilation containment for a transuranium processing plant at the Oak Ridge National Laboratory. A fire-safety survey by an independent fire-protection consulting company had identified the HEPA filters in the facility's off-gas containment ventilation system as being at risk from fire effects. Independently studied were the ventilation networks and flow dynamics, and typical fuel loads were analyzed. It was found that virtually no condition for fire initiation exists and that, even if a fire started, its consequences would be minimal as a result of standard shut-down procedures. Moreover, the installed fire-protection system would limit any fire and thus would further reduce smoke or heat exposure to the ventilation components. 4 references, 4 figures, 5 tables

  6. Modeling and numerical analysis of granite rock specimen under mechanical loading and fire

    Institute of Scientific and Technical Information of China (English)

    Luc Leroy Ngueyep. Mambou; Joseph Ndop; Jean-Marie Bienvenu Ndjaka

    2015-01-01

    The effect of ISO 834 fire on the mechanical properties of granite rock specimen submitted to uniaxial loading is numerically investigated. Based on Newton’s second law, the rate-equation model of granite rock specimen under mechanical load and fire is established. The effect of heat treatment on the me-chanical performance of granite is analyzed at the center and the ends of specimen. At the free end of granite rock specimen, it is shown that from 20 ?C to 500 ?C, the internal stress and internal strain are weak; whereas above 500 ?C, they start to increase rapidly, announcing the imminent collapse. At the center of specimen, the analysis of the internal stress and internal strain reveals that the fire reduces the mechanical performance of granite significantly. Moreover, it is found that after 3 min of exposure to fire, the mechanical energy necessary to fragment the granite can be reduced up to 80%.

  7. Risk analysis of the LHC underground area fire risk due to faulty electrical equipment

    CERN Document Server

    Harrison, A

    2007-01-01

    The European Organisation for Nuclear Research (CERN) in Geneva, Switzerland, is currently building the latest generation of particle accelerators, the LHC (Large Hadron Collider). The machine is housed in a circular tunnel of 27 km of circumference and is situated approximately 100 metres beneath the surface astride the Franco-Swiss border. Electrically induced fires in the LHC are a major concern, since an incident could present a threat to CERN personnel as well as the public. Moreover, the loss of equipment would result in significant costs and downtime. However, the amount of electrical equipment in the underground area required for operation, supervision and control of the machine is essential. Thus the present thesis is assessing the risk of fire due to faulty electrical equipment in both a qualitative as well as quantitative way. The recommendations following the qualitative analysis suggest the introduction of fire protection zones for the areas with the highest risk of fire due to a combination of p...

  8. Analytical tools for the analysis of fire debris. A review: 2008-2015.

    Science.gov (United States)

    Martín-Alberca, Carlos; Ortega-Ojeda, Fernando Ernesto; García-Ruiz, Carmen

    2016-07-20

    The analysis of fire debris evidence might offer crucial information to a forensic investigation, when for instance, there is suspicion of the intentional use of ignitable liquids to initiate a fire. Although the evidence analysis in the laboratory is mainly conducted by a handful of well-established methodologies, during the last eight years several authors proposed noteworthy improvements on these methodologies, suggesting new interesting approaches. This review critically outlines the most up-to-date and suitable tools for the analysis and interpretation of fire debris evidence. The survey about analytical tools covers works published in the 2008-2015 period. It includes sources of consensus-classified reference samples, current standard procedures, new proposals for sample extraction and analysis, and the most novel statistical tools. In addition, this review provides relevant knowledge on the distortion effects of the ignitable liquid chemical fingerprints, which have to be considered during interpretation of results. PMID:27251852

  9. Experimental study and advanced CFD simulation of fire safety performance of building external wall insulation system

    OpenAIRE

    Yan Zhenghua; Zhao Chenggang; Liu Yan; Deng Xiaobing; Ceng Xubin; Liu Songlin; Lan Bin; Nilsson Richard; Jeansson Sebastian

    2013-01-01

    Large scale fire tests of building external wall insulation system were conducted. In the experiment, thermal-couples were mounted to measure the insulation system surface temperature and the gas temperature inside rooms at the second and third floors. Photos were also taken during the fire tests. The measurement provides information of the ignition and fire spread of the external insulation system which consists of surface protection layer, glass fibre net, bonding thin layer, anchor and the...

  10. Numerical field model simulation of fire and heat transfer in a rectangular compartment

    OpenAIRE

    Thorkildsen, Kenneth J.

    1992-01-01

    Approved for public release; distribution is unlimited Shipboard fires have been the bane of mariners since man's earliest attempts to sail the sea. Understanding the behavior of fire in an enclosed space such as those found on today's modern seagoing vessels will greatly enhance the mariner's ability to combat or prevent them. In a joint effort between the Naval Postgraduate School and the University of Notre Dame a computer code has been developed to model a full scale fire in a closed...

  11. Detection, Emission Estimation and Risk Prediction of Forest Fires in China Using Satellite Sensors and Simulation Models in the Past Three Decades—An Overview

    OpenAIRE

    Cheng Liu; Li-Min Yang; Jia-Hua Zhang; Feng-Mei Yao; Vijendra K. Boken

    2011-01-01

    Forest fires have major impact on ecosystems and greatly impact the amount of greenhouse gases and aerosols in the atmosphere. This paper presents an overview in the forest fire detection, emission estimation, and fire risk prediction in China using satellite imagery, climate data, and various simulation models over the past three decades. Since the 1980s, remotely-sensed data acquired by many satellites, such as NOAA/AVHRR, FY-series, MODIS, CBERS, and ENVISAT, have been widely utilized for ...

  12. Analysis of pressurization of plutonium oxide storage vials during a postulated fire

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Kesterson, M.; Hensel, S.

    2015-02-10

    The documented safety analysis for the Savannah River Site evaluates the consequences of a postulated 1000 °C fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage vial. To enable evaluation of the dose consequences, pressure transients and venting flow rates have been calculated for exposure of the storage vial to the fire. A standard B vial with a capacity of approximately 8 cc was selected for analysis. The analysis compares the pressurization rate from heating and evaporation of moisture adsorbed onto the plutonium oxide contents of the vial with the pressure loss due to venting of gas through the threaded connection between the vial cap and body. Tabulated results from the analysis include maximum pressures, maximum venting velocities, and cumulative vial volumes vented during the first 10 minutes of the fire transient. Results are obtained for various amounts of oxide in the vial, various amounts of adsorbed moisture, different vial orientations, and different surface fire exposures.

  13. Intercomparison of cloud model simulations of Arctic mixed-phase boundary layer clouds observed during SHEBA/FIRE-ACE

    Directory of Open Access Journals (Sweden)

    Mikhail Ovchinnikov

    2011-06-01

    Full Text Available An intercomparison of six cloud-resolving and large-eddy simulation models is presented. This case study is based on observations of a persistent mixed-phase boundary layer cloud gathered on 7 May, 1998 from the Surface Heat Budget of Arctic Ocean (SHEBA and First ISCCP Regional Experiment - Arctic Cloud Experiment (FIRE-ACE. Ice nucleation is constrained in the simulations in a way that holds the ice crystal concentration approximately fixed, with two sets of sensitivity runs in addition to the baseline simulations utilizing different specified ice nucleus (IN concentrations. All of the baseline and sensitivity simulations group into two distinct quasi-steady states associated with either persistent mixed-phase clouds or all-ice clouds after the first few hours of integration, implying the existence of multiple equilibria. These two states are associated with distinctly different microphysical, thermodynamic, and radiative characteristics. Most but not all of the models produce a persistent mixed-phase cloud qualitatively similar to observations using the baseline IN/crystal concentration, while small increases in the IN/crystal concentration generally lead to rapid glaciation and conversion to the all-ice state. Budget analysis indicates that larger ice deposition rates associated with increased IN/crystal concentrations have a limited direct impact on dissipation of liquid in these simulations. However, the impact of increased ice deposition is greatly enhanced by several interaction pathways that lead to an increased surface precipitation flux, weaker cloud top radiative cooling and cloud dynamics, and reduced vertical mixing, promoting rapid glaciation of the mixed-phase cloud for deposition rates in the cloud layer greater than about 1-2x10-5 g kg-1 s-1. These results indicate the critical importance of precipitation-radiative-dynamical interactions in simulating cloud phase, which have been neglected in previous fixed-dynamical parcel

  14. 77 FR 37717 - Electrical Cable Test Results and Analysis During Fire Exposure

    Science.gov (United States)

    2012-06-22

    ... COMMISSION Electrical Cable Test Results and Analysis During Fire Exposure AGENCY: Nuclear Regulatory... the Commission) is making the proposed draft, NUREG-2128, ``Electrical Cable Test Results and Analysis...- 0146. You may submit comments by the following methods: Federal Rulemaking Web site: Go to...

  15. Thermal radiation of di-tert-butyl peroxide pool fires-Experimental investigation and CFD simulation

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Hyunjoo [Umicore Korea Limited, 410 Chaam-dong, Cheonan-city, Chungnam, 330-200 (Korea, Republic of); Wehrstedt, Klaus-Dieter [Federal Institute for Materials Research and Testing (BAM), Working Group ' Explosive Substances of Chemical Industries' , Unter den Eichen 87, D-12205 Berlin (Germany); Vela, Iris [University of Duisburg-Essen, Institute for Chemical Engineering I, Universitaetsstrasse 5, D-45141 Essen (Germany); Schoenbucher, Axel, E-mail: axel.schoenbucher@uni-due.de [University of Duisburg-Essen, Institute for Chemical Engineering I, Universitaetsstrasse 5, D-45141 Essen (Germany)

    2009-08-15

    Instantaneous and time averaged flame temperatures T-bar, surface emissive power SEP-bar and time averaged irradiances E-bar of di-tert-butyl peroxide (DTBP) pool fires with d = 1.12 and 3.4 m are investigated experimentally and by CFD simulation. Predicted centerline temperature profiles for d = 1.12 m are in good agreement with the experimental emission temperature profiles for x/d > 0.9. For d = 3.4 m the CFD predicted maximum centerline temperature at x/d = 1.4 is 1440 K whereas the emission temperature experimentally determined from thermograms at x/d {approx} 1.3 is 1560 K. The predicted surface emissive power for d = 1.12 m is 115 kW/m{sup 2} in comparison to the measured surface emissive power of 130 kW/m{sup 2} whereas for d = 3.4 m these values are 180 and 250 kW/m{sup 2}. The predicted distance dependent irradiances agree well with the measured irradiances.

  16. Thermal radiation of di-tert-butyl peroxide pool fires-Experimental investigation and CFD simulation.

    Science.gov (United States)

    Chun, Hyunjoo; Wehrstedt, Klaus-Dieter; Vela, Iris; Schönbucher, Axel

    2009-08-15

    Instantaneous and time averaged flame temperatures T , surface emissive power SEP and time averaged irradiances E of di-tert-butyl peroxide (DTBP) pool fires with d=1.12 and 3.4m are investigated experimentally and by CFD simulation. Predicted centerline temperature profiles for d=1.12m are in good agreement with the experimental emission temperature profiles for x/d>0.9. For d=3.4m the CFD predicted maximum centerline temperature at x/d=1.4 is 1440 K whereas the emission temperature experimentally determined from thermograms at x/d approximately 1.3 is 1560 K. The predicted surface emissive power for d=1.12m is 115 kW/m(2) in comparison to the measured surface emissive power of 130 kW/m(2) whereas for d=3.4m these values are 180 and 250 kW/m(2). The predicted distance dependent irradiances agree well with the measured irradiances. PMID:19185989

  17. Simulation of emission performance and combustion efficiency in biomass fired circulating fluidized bed combustors

    Energy Technology Data Exchange (ETDEWEB)

    Gungor, Afsin [Nigde University, Faculty of Engineering and Architecture, Department of Mechanical Engineering, 51100 Nigde (Turkey)

    2010-04-15

    In this study, the combustion efficiency and the emission performance of biomass fired CFBs are tested via a previously published 2D model [Gungor A. Two-dimensional biomass combustion modeling of CFB. Fuel 2008; 87: 1453-1468.] against two published comprehensive data sets. The model efficiently simulates the outcome with respect to the excess air values, which is the main parameter that is verified. The combustion efficiency of OC changes between 82.25 and 98.66% as the excess air increases from 10 to 116% with the maximum error of about 8.59%. The rice husk combustion efficiency changes between 98.05 and 97.56% as the bed operational velocity increases from 1.2 to 1.5 m s{sup -1} with the maximum error of about 7.60%. CO and NO{sub x} emissions increase with increasing bed operational velocity. Increasing excess air results in slightly higher levels of NO{sub x} emission. A significant amount of combustion occurs in the upper zone due to the high volatile content of the biomass fuels. (author)

  18. Giant clumps in the FIRE simulations: a case study of a massive high-redshift galaxy

    CERN Document Server

    Oklopcic, Antonija; Feldmann, Robert; Keres, Dusan; Faucher-Giguere, Claude-Andre; Murray, Norman

    2016-01-01

    The morphology of massive star-forming galaxies at high redshift is often dominated by giant clumps of mass ~10^8-10^9 Msun and size ~100-1000 pc. Previous studies have proposed that giant clumps might have an important role in the evolution of their host galaxy, particularly in building the central bulge. However, this depends on whether clumps live long enough to migrate from their original location in the disc or whether they get disrupted by their own stellar feedback before reaching the centre of the galaxy. We use cosmological hydrodynamical simulations from the FIRE (Feedback in Realistic Environments) project that implement explicit treatments of stellar feedback and ISM physics to study the properties of these clumps. We follow the evolution of giant clumps in a massive (stellar mass ~10^10.8 Msun at z=1), discy, gas-rich galaxy from redshift z>2 to z=1. Even though the clumpy phase of this galaxy lasts over a gigayear, individual gas clumps are short-lived, with mean lifetime of massive clumps of ~2...

  19. Validation analysis of pool fire experiment (Run-F7) using SPHINCS code

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Akira [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center; Tajima, Yuji

    1998-04-01

    SPHINCS (Sodium Fire Phenomenology IN multi-Cell System) code has been developed for the safety analysis of sodium fire accident in a Fast Breeder Reactor. The main features of the SPHINCS code with respect to the sodium pool fire phenomena are multi-dimensional modeling of the thermal behavior in sodium pool and steel liner, modeling of the extension of sodium pool area based on the sodium mass conservation, and equilibrium model for the chemical reaction of pool fire on the flame sheet at the surface of sodium pool during. Therefore, the SPHINCS code is capable of temperature evaluation of the steel liner in detail during the small and/or medium scale sodium leakage accidents. In this study, Run-F7 experiment in which the sodium leakage rate is 11.8 kg/hour has been analyzed. In the experiment the diameter of the sodium pool is approximately 60 cm and the maximum steel liner temperature was 616 degree C. The analytical results tell us the agreement between the SPHINCS analysis and the experiment is excellent with respect to the time history and spatial distribution of the liner temperature, sodium pool extension behavior, as well as atmosphere gas temperature. It is concluded that the pool fire modeling of the SPHINCS code has been validated for this experiment. The SPHINCS code is currently applicable to the sodium pool fire phenomena and the temperature evaluation of the steel liner. The experiment series are continued to check some parameters, i.e., sodium leakage rate and the height of sodium leakage. Thus, the author will analyze the subsequent experiments to check the influence of the parameters and applies SPHINCS to the sodium fire consequence analysis of fast reactor. (author)

  20. Physics-Based Simulator for NEO Exploration Analysis & Simulation

    Science.gov (United States)

    Balaram, J.; Cameron, J.; Jain, A.; Kline, H.; Lim, C.; Mazhar, H.; Myint, S.; Nayar, H.; Patton, R.; Pomerantz, M.; Quadrelli, M.; Shakkotai, P.; Tso, K.

    2011-01-01

    As part of the Space Exploration Analysis and Simulation (SEAS) task, the National Aeronautics and Space Administration (NASA) is using physics-based simulations at NASA's Jet Propulsion Laboratory (JPL) to explore potential surface and near-surface mission operations at Near Earth Objects (NEOs). The simulator is under development at JPL and can be used to provide detailed analysis of various surface and near-surface NEO robotic and human exploration concepts. In this paper we describe the SEAS simulator and provide examples of recent mission systems and operations concepts investigated using the simulation. We also present related analysis work and tools developed for both the SEAS task as well as general modeling, analysis and simulation capabilites for asteroid/small-body objects.

  1. Using thermal analysis to evaluate the fire effects on organic matter content of Andisols

    Directory of Open Access Journals (Sweden)

    J. Neris

    2013-09-01

    Full Text Available Soil organic compounds play a relevant role in aggregate stability and thus, in the susceptibility of soils to erosion. Thermal analysis (N2 and air and chemical oxidation techniques (dichromate and permanganate oxidation were used to evaluate the effects of a forest fire on the organic matter of Andisols. Both thermal analysis and chemical methods showed a decrease in the organic matter content and an increase in the recalcitrance of the remaining organic compounds in the burned zones. Thermal analysis indicated an increase in the thermal stability of the organic compounds of fire-affected soils and a lower content of both labile and recalcitrant pools as a consequence of the fire. However, this decrease was relatively higher in the labile pool and lower in the recalcitrant one, indicative of an increase in the recalcitrance of the remaining organic compounds. Apparently, black carbon did not burn under our experimental conditions. Under N2, the results showed a lower labile and a higher recalcitrant and refractory contents in burned and some unburned soils, possibly due to the lower decomposition rate under N2 flux. Thermal analysis using O2 and the chemical techniques showed a positive relation, but noticeable differences in the total amount of the labile pool. Thermal analysis methods provide direct quantitative information useful to characterize the soil organic matter quality and to evaluate the effects of fire on soils.

  2. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow

    International Nuclear Information System (INIS)

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons-a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  3. Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.H., E-mail: hlh@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China); Huo, R.; Yang, D. [State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2009-07-15

    The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons-a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

  4. Preliminary fire hazard analysis for the PUTDR and TRU trenches in the Solid Waste Burial Ground

    Energy Technology Data Exchange (ETDEWEB)

    Gaschott, L.J.

    1995-06-16

    This document represents the Preliminary Fire Hazards Analysis for the Pilot Unvented TRU Drum Retrieval effort and for the Transuranic drum trenches in the low level burial grounds. The FHA was developed in accordance with DOE Order 5480.7A to address major hazards inherent in the facility.

  5. Preliminary fire hazard analysis for the PUTDR and TRU trenches in the Solid Waste Burial Ground

    International Nuclear Information System (INIS)

    This document represents the Preliminary Fire Hazards Analysis for the Pilot Unvented TRU Drum Retrieval effort and for the Transuranic drum trenches in the low level burial grounds. The FHA was developed in accordance with DOE Order 5480.7A to address major hazards inherent in the facility

  6. Fire hazards analysis for the replacement cross-site transfer system, project W-058

    International Nuclear Information System (INIS)

    The fire hazards analysis assess the risk from fire and determines compliance with the applicable criteria of DOE 5480.7A, DOE 6430.1A, and RLID 5480.7. (Project W-058 will provide encased pipelines to connect the SY Tank Farms in 200 West Area with the tank farms in 200 East Area via an interface with the 244-A lift station. Function of the cross-site transfer system will be to transfer radioactive waste from the SY Tank Farm to treatment, storage, and disposal facilities in 200 East Area.)

  7. State of the art review of sodium fire analysis and current notions for improvements

    International Nuclear Information System (INIS)

    Sodium releases from postulated pipe ruptures, as well as failures of sodium handling equipment in liquid metal fast breeder reactors, may lead to substantial pressure-temperature transients in the sodium system cells, as well as in the reactor containment building. Sodium fire analyses are currently performed with analytical tools, such as the SPRAY, SOMIX, SPOOL-FIRE and SOFIRE-II codes. A review and evaluation of the state-of-the-art in sodium fire analysis is presented, and suggestions for further improvements are made. This work is based, in part, on studies made at Brookhaven National Laboratory during the past several years in the areas of model development and improvement associated with the accident analyses of LMFBRs. (author)

  8. Study on the scenario of the fire incident and related analysis

    International Nuclear Information System (INIS)

    On March 11,1997, Bituminization Demonstration Facility (BDF) of PNC Tokai Works made fire and explosion incident. As soon as the Incident Investigation Committee was established and began its activity just after the incident, we PNC also began our investigation of the damage, operational records, and everything considered useful to study cause of the incident to contribute to the committee. The cause is not yet completely clarified, but it is now believed that the fire occurred as a result of several unfavorable operational condition changes and that the cause is so complicated. Such operational condition changes are slower feed rate of waste solution, higher extruder torque, higher extruder temperature, introduction of precipitation from the bottom of waste solution vessel, and so on. Based on the investigation and study of much data, an assumable scenario has been developed. This report describes PNC 's view, as of middle October 1997, on the scenario of the fire incident and result of related analysis. (authors)

  9. State-of-the-art review of sodium fire analysis and current notions for improvements

    International Nuclear Information System (INIS)

    Sodium releases from postulated pipe ruptures, as well as failures of sodium handling equipment in liquid metal fast breeder reactors, may lead to substantial pressure-temperature transients in the sodium system cells, as well as in the reactor containment building. Sodium fire analyses are currently performed with analytical tools, such as the SPRAY, SOMIX, SPOOL-FIRE and SOFIRE-II codes. A review and evaluation of the state-of-the-art in sodium fire analysis is presented, and suggestions for further improvements are made. This work is based, in part, on studies made at Brookhaven National Laboratory during the past several years in the areas of model development and improvement associated with the accident analyses of LMFBRs

  10. Fire PSA for MAPS

    International Nuclear Information System (INIS)

    Full text: Fire hazard has been identified as one of the major contributors to a plant's operational risk. As a result of several fire incidences at nuclear power plants, internal fire is included in level 1 probabilistic safety assessment (PSA) studies of nuclear power plants (NPPs). This activity is termed as fire risk analysis or fire PSA. In this context, fire PSA studies were initiated for Madras Atomic Power Station (MAPS). Fire PSA extends the consequence analysis of a fire event towards core damage, in case of nuclear power plants. The paper summarises and gives an overview of the fire PSA procedure performed for MAPS. It highlights the issues associated with the collection of data and information needed for fire modelling. An estimate of the contribution of fire to core damage frequency (CDF) has been obtained

  11. Fire safety

    International Nuclear Information System (INIS)

    According to experience and probabilistic risk assessments, fires present a significant hazard in a nuclear power plant. Fires may be initial events for accidents or affect safety systems planned to prevent accidents and to mitigate their consequences. The project consists of theoretical work, experiments and simulations aiming to increase the fire safety at nuclear power plants. The project has four target areas: (1) to produce validated models for numerical simulation programmes, (2) to produce new information on the behavior of equipment in case of fire, (3) to study applicability of new active fire protecting systems in nuclear power plants, and (4) to obtain quantitative knowledge of ignitions induced by important electric devices in nuclear power plants. These topics have been solved mainly experimentally, but modelling at different level is used to interpret experimental data, and to allow easy generalisation and engineering use of the obtained data. Numerical fire simulation has concentrated in comparison of CFD modelling of room fires, and fire spreading on cables on experimental data. So far the success has been good to fair. A simple analytical and numerical model has been developed for fire effluents spreading beyond the room of origin in mechanically strongly ventilated compartments. For behaviour of equipment in fire several full scale and scaled down calorimetric experiments were carried out on electronic cabinets, as well as on horizontal and vertical cable trays. These were carried out to supply material for CFD numerical simulation code validation. Several analytical models were developed and validated against obtained experimental results to allow quick calculations for PSA estimates as well as inter- and extrapolations to slightly different objects. Response times of different commercial fire detectors were determined for different types of smoke, especially emanating from smoldering and flaming cables to facilitate selection of proper detector

  12. WHC-SD-W252-FHA-001, Rev. 0: Preliminary fire hazard analysis for Phase II Liquid Effluent Treatment and Disposal Facility, Project W-252

    International Nuclear Information System (INIS)

    A Fire Hazards Analysis was performed to assess the risk from fire and other related perils and the capability of the facility to withstand these hazards. This analysis will be used to support design of the facility

  13. Solar activity as a possible cause of large forest fires--a case study: analysis of the Portuguese forest fires.

    Science.gov (United States)

    Gomes, J F P; Radovanovic, M

    2008-05-01

    Fires of large dimension destroy forests, harvests and housing objects. Apart from that combustion products and burned surfaces become large ecological problems. Very often fires emerge simultaneously on different locations of a region so a question could be asked if they always have been a consequence of negligence, pyromania, high temperatures or maybe there has been some other cause. This paper is an attempt of establishing the possible connection between forest fires that numerous satellites registered and activities happening on the Sun immediately before fires ignite. Fires emerged on relatively large areas from Portugal and Spain on August 2005, as well as on other regions of Europe. The cases that have been analyzed show that, in every concrete situation, an emission of strong electromagnetic and thermal corpuscular energy from highly energetic regions that were in geo-effective position had preceded the fires. Such emissions have, usually, very high energy and high speeds of particles and come from coronary holes that also have been either in the very structure or in the immediate closeness of the geo-effective position. It should also be noted that the solar wind directed towards the Earth becomes weaker with deeper penetration towards the topographic surface. However, the results presented in this paper suggest that, there is a strong causality relationship between solar activity and the ignition of these forest fires taking place in South-western Europe. PMID:18291443

  14. A simulation study on the effects of dendritic morphology on layer V PFC pyramidal cell firing behavior

    Directory of Open Access Journals (Sweden)

    Maria Psarrou

    2014-03-01

    Full Text Available The majority of neuronal cells found in the cerebral cortex are pyramidal neurons. Their function has been associated with higher cognitive and emotional functions. Pyramidal neurons have a characteristic structure, consisting of a triangular shaped soma whereon descend two extended and complex dendritic trees, and a long bifurcated axon. All the morphological components of the pyramidal neurons exhibit significant variability across different brain areas and layers. Pyramidal cells receive numerous synaptic inputs along their structure, integration of which in space and in time generates local dendritic spikes that shape their firing pattern. In addition, synaptic integration is influenced by voltage-gated and ion channels, which are expressed in a large repertoire by pyramidal neurons. Electrophysiological categories of pyramidal cells can be established, based on the action potential frequency, generated from a fixed somatic stimulus: (1 cells that fire repetitive action potentials (Regular Spiking – RS, (2 cells that fire clusters of 2 – 5 action potentials with short ISIs (Intrinsic Bursting – IB, and (3 cells that fire in repetitive clusters of 2 – 5 action potentials with short ISIs (Repetitive Oscillatory Bursts – ROB. In vitro and in silico scientific studies, correlate the firing patterns of the pyramidal neurons to their morphological features. This study provides a quantitatively analysis via compartmental neuronal modelling of the effects of dendritic morphology and distribution and concentration of ionic mechanisms, along the basal and/or apical dendrites on the firing behavior of a 112-set of layer V rat PFC pyramidal cells. We focus on how particular morphological and passive features of the dendritic trees shape the neuronal firing patterns. Our results suggest that specific morphological parameters (such as total length, volume and branch number can discriminate the cells as RS or IB, regardless of what is the

  15. Long-term changes in soil erosion due to forest fires. A rainfall simulation approach in Eastern Spain

    Science.gov (United States)

    Cerdà, Artemi; Keesstra, Saskia; Pereira, Paulo; Matrix-Solera, Jorge; Giménez-Morera, Antonio; Úbeda, Xavier; Francos, Marcos; Alcañiz, Meritxell; Jordán, Antonio

    2016-04-01

    Soils are affected by the impacts of wildfires (Dlapa et al., 2013; Pereira et al., 2014; Tsibart et al., 2014; Dlapa et al., 2015, Hedo et al., 2015; Tessler et al., 2015). Soil erosion rates are highly affected by forest fires due to the removal of the above ground vegetation, the heat impact on the soil, the reduction of the organic matter, the ash cover, and the changes introduced by the rainfall on the soil surface (Lasanta and Cerdà, 2005; Mataix-Solera et al., 2011; Novara et al., 2011; Novara et al., 2013; Keesstra et al., 2014; Hedo et al., 2015; Pereira, 2015). Most of the research carried out on forest fire affected land paid attention to the "window of disturbance", which is the period that the soil losses are higher than before the forest fire and that last for few years (Cerdà, 1998a; Cerdà 1998b, Pérez-Cabello et al., 2011; Bodí et al., 2011; Bodí et al., 2012; Pereira et al., 2013: Pereira et al., 2015). However, the spatial and temporal variability of soil erosion is very high as a result of the uneven temporal and spatial distribution of the rainfall (Novara et al., 2011; Bisantino et al., 2015; Gessesse et al., 2015; Ochoa et al., 2015), and the window of disturbance cannot be easily found under natural rainfall. In order to understand the evolution of soil erosion after forest fires it is necessary to monitor fire affected sites over a long period of time, which will enable the assessment of the period affected by the window of disturbance (see Cerdà and Doerr, 2005). However, it is also possible to do measurements and experiments in areas with a different fire history. This will give us information about the temporal changes in soil erosion after forest fire. To reduce the spatial variability of rainfall we can use simulated rainfall that can be applied at multiple site with the same rainfall intensity and duration. For this purpose rainfall simulation can be of great help, in the laboratory (Moreno et al., 2014; Sadegui et al., 2015

  16. Using thermal analysis to evaluate the fire effects on organic matter content of Andisols

    OpenAIRE

    J. Neris; Hernández-Moreno, J. M.; C Jiménez; M. Tejedor

    2013-01-01

    Soil organic compounds play a relevant role in aggregate stability and thus, in the susceptibility of soils to erosion. Thermal analysis (N2 and air) and chemical oxidation techniques (dichromate and permanganate oxidation) were used to evaluate the effects of a forest fire on the organic matter of Andisols. Both thermal analysis and chemical methods showed a decrease in the organic matter content and an increase in the recalcitrance of the remaining organic compounds in the burned zones. The...

  17. Analysis of the evaporative towers cooling system of a coal-fired power plant

    OpenAIRE

    Laković Mirjana S.; Laković Slobodan V.; Banjac Miloš J.

    2012-01-01

    The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers fo...

  18. Thermal Performance and Economic Analysis of 210 MWe Coal-Fired Power Plant

    OpenAIRE

    Ravinder Kumar; Avdhesh Kr. Sharma; P C Tewari

    2014-01-01

    This paper presents the thermal and economic performance of a 210 MWe coal-fired power plant situated in North India. Analysis is used to predict coal consumption rate, overall thermal efficiency, mass flow rate of steam through boiler, and Net present value (NPV) of plant for given load. Thermodynamic analysis was carried out using mass and energy equations followed by empirical correlations. Predicted mass flow rate of steam, coal consumption rate, and thermal efficiency give fair agreement...

  19. Accuracy analysis of distributed simulation systems

    Science.gov (United States)

    Lin, Qi; Guo, Jing

    2010-08-01

    Existed simulation works always emphasize on procedural verification, which put too much focus on the simulation models instead of simulation itself. As a result, researches on improving simulation accuracy are always limited in individual aspects. As accuracy is the key in simulation credibility assessment and fidelity study, it is important to give an all-round discussion of the accuracy of distributed simulation systems themselves. First, the major elements of distributed simulation systems are summarized, which can be used as the specific basis of definition, classification and description of accuracy of distributed simulation systems. In Part 2, the framework of accuracy of distributed simulation systems is presented in a comprehensive way, which makes it more sensible to analyze and assess the uncertainty of distributed simulation systems. The concept of accuracy of distributed simulation systems is divided into 4 other factors and analyzed respectively further more in Part 3. In Part 4, based on the formalized description of framework of accuracy analysis in distributed simulation systems, the practical approach are put forward, which can be applied to study unexpected or inaccurate simulation results. Following this, a real distributed simulation system based on HLA is taken as an example to verify the usefulness of the approach proposed. The results show that the method works well and is applicable in accuracy analysis of distributed simulation systems.

  20. Fire Hazard Analysis for the Cold Vacuum Drying facility (CVD) Facility

    CERN Document Server

    Singh, G

    2000-01-01

    The CVDF is a nonreactor nuclear facility that will process the Spent Nuclear Fuels (SNF) presently stored in the 105-KE and 105-KW SNF storage basins. Multi-canister overpacks (MCOs) will be loaded (filled) with K Basin fuel transported to the CVDF. The MCOs will be processed at the CVDF to remove free water from the fuel cells (packages). Following processing at the CVDF, the MCOs will be transported to the CSB for interim storage until a long-term storage solution can be implemented. This operation is expected to start in November 2000. A Fire Hazard Analysis (FHA) is required for all new facilities and all nonreactor nuclear facilities, in accordance with U.S. Department of Energy (DOE) Order 5480.7A, Fire Protection. This FHA has been prepared in accordance with DOE 5480.7A and HNF-PRO-350, Fire Hazard Analysis Requirements. Additionally, requirements or criteria contained in DOE, Richland Operations Office (RL) RL Implementing Directive (RLID) 5480.7, Fire Protection, or other DOE documentation are cite...

  1. Testing of one-inch UF{sub 6} cylinder valves under simulated fire conditions

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, P.G. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

    1991-12-31

    Accurate computational models which predict the behavior of UF{sub 6} cylinders exposed to fires are required to validate existing firefighting and emergency response procedures. Since the cylinder valve is a factor in the containment provided by the UF{sub 6} cylinder, its behavior under fire conditions has been a necessary assumption in the development of such models. Consequently, test data is needed to substantiate these assumptions. Several studies cited in this document provide data related to the behavior of a 1-inch UF{sub 6} cylinder valve in fire situations. To acquire additional data, a series of tests were conducted at the Paducah Gaseous Diffusion Plant (PGDP) under a unique set of test conditions. This document describes this testing and the resulting data.

  2. Simulation of co-firing coal and biomass in circulating fluidized beds

    International Nuclear Information System (INIS)

    Highlights: ► The effect of the biomass share on CO, NOx and SO2 emissions are investigated. ► New model shows similar emissions trends for co-firing to industrial data. ► Biomass share has a positive effect on lowering the emissions in co-firing. - Abstract: In this study, the effect of the biomass share on CO, NOx and SO2 emissions are investigated to reveal the benefits of co-firing biomass and coal in CFBs by using a developed model. The results are compared with two published comprehensive data sets. The results show that CO, NOx and SO2 emissions decrease as the biomass share increases for industrial scale CFB combustors.

  3. Urban Fire Risk Clustering Method Based on Fire Statistics

    Institute of Scientific and Technical Information of China (English)

    WU Lizhi; REN Aizhu

    2008-01-01

    Fire statistics and fire analysis have become important ways for us to understand the law of fire,prevent the occurrence of fire, and improve the ability to control fire. According to existing fire statistics, the weighted fire risk calculating method characterized by the number of fire occurrence, direct economic losses,and fire casualties was put forward. On the basis of this method, meanwhile having improved K-mean clus-tering arithmetic, this paper established fire dsk K-mean clustering model, which could better resolve the automatic classifying problems towards fire risk. Fire risk cluster should be classified by the absolute dis-tance of the target instead of the relative distance in the traditional cluster arithmetic. Finally, for applying the established model, this paper carded out fire risk clustering on fire statistics from January 2000 to December 2004 of Shenyang in China. This research would provide technical support for urban fire management.

  4. SYSTEMS SAFETY ANALYSIS FOR FIRE EVENTS ASSOCIATED WITH THE ECRB CROSS DRIFT

    International Nuclear Information System (INIS)

    The purpose of this analysis is to systematically identify and evaluate fire hazards related to the Yucca Mountain Site Characterization Project (YMP) Enhanced Characterization of the Repository Block (ECRB) East-West Cross Drift (commonly referred to as the ECRB Cross-Drift). This analysis builds upon prior Exploratory Studies Facility (ESF) System Safety Analyses and incorporates Topopah Springs (TS) Main Drift fire scenarios and ECRB Cross-Drift fire scenarios. Accident scenarios involving the fires in the Main Drift and the ECRB Cross-Drift were previously evaluated in ''Topopah Springs Main Drift System Safety Analysis'' (CRWMS M and O 1995) and the ''Yucca Mountain Site Characterization Project East-West Drift System Safety Analysis'' (CRWMS M and O 1998). In addition to listing required mitigation/control features, this analysis identifies the potential need for procedures and training as part of defense-in-depth mitigation/control features. The inclusion of this information in the System Safety Analysis (SSA) is intended to assist the organization(s) (e.g., Construction, Environmental Safety and Health, Design) responsible for these aspects of the ECRB Cross-Drift in developing mitigation/control features for fire events, including Emergency Refuge Station(s). This SSA was prepared, in part, in response to Condition/Issue Identification and Reporting/Resolution System (CIRS) item 1966. The SSA is an integral part of the systems engineering process, whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach is used which incorporates operating experiences and recommendations from vendors, the constructor and the operating contractor. The risk assessment in this analysis characterizes the scenarios associated with fires in terms of relative risk and includes recommendations for mitigating all identified hazards. The priority for recommending and implementing mitigation control features is: (1) Incorporate

  5. Long-term changes in soil erosion due to forest fires. A rainfall simulation approach in Eastern Spain

    Science.gov (United States)

    Cerdà, Artemi; Keesstra, Saskia; Pereira, Paulo; Matrix-Solera, Jorge; Giménez-Morera, Antonio; Úbeda, Xavier; Francos, Marcos; Alcañiz, Meritxell; Jordán, Antonio

    2016-04-01

    Soils are affected by the impacts of wildfires (Dlapa et al., 2013; Pereira et al., 2014; Tsibart et al., 2014; Dlapa et al., 2015, Hedo et al., 2015; Tessler et al., 2015). Soil erosion rates are highly affected by forest fires due to the removal of the above ground vegetation, the heat impact on the soil, the reduction of the organic matter, the ash cover, and the changes introduced by the rainfall on the soil surface (Lasanta and Cerdà, 2005; Mataix-Solera et al., 2011; Novara et al., 2011; Novara et al., 2013; Keesstra et al., 2014; Hedo et al., 2015; Pereira, 2015). Most of the research carried out on forest fire affected land paid attention to the "window of disturbance", which is the period that the soil losses are higher than before the forest fire and that last for few years (Cerdà, 1998a; Cerdà 1998b, Pérez-Cabello et al., 2011; Bodí et al., 2011; Bodí et al., 2012; Pereira et al., 2013: Pereira et al., 2015). However, the spatial and temporal variability of soil erosion is very high as a result of the uneven temporal and spatial distribution of the rainfall (Novara et al., 2011; Bisantino et al., 2015; Gessesse et al., 2015; Ochoa et al., 2015), and the window of disturbance cannot be easily found under natural rainfall. In order to understand the evolution of soil erosion after forest fires it is necessary to monitor fire affected sites over a long period of time, which will enable the assessment of the period affected by the window of disturbance (see Cerdà and Doerr, 2005). However, it is also possible to do measurements and experiments in areas with a different fire history. This will give us information about the temporal changes in soil erosion after forest fire. To reduce the spatial variability of rainfall we can use simulated rainfall that can be applied at multiple site with the same rainfall intensity and duration. For this purpose rainfall simulation can be of great help, in the laboratory (Moreno et al., 2014; Sadegui et al., 2015

  6. Simulation of impact assesment of crown forest fires on boudary layer of atmosphere using software PHOENICS

    Science.gov (United States)

    Soprunenko, Elina E.; Perminov, Valeriy; Reyno, Vladimir V.; Loboda, Egor L.

    2015-11-01

    Mathematical model of heat and mass transfer of crown forest fire is used in this paper, which is developed on the base of experimental research data and laws and methods of mechanics of reacting media. The numerical calculation carried out using software PHOENICS for non stationary three dimensional case. K-Ɛ model of turbulence is taken into account. It is studied the influence of temperature and wind velocity in boundary layer of atmosphere on the turbulent kinematic viscosity coefficient value and distribution of temperature above the crown forest fire front.

  7. Simulation modeling and analysis with Arena

    CERN Document Server

    Altiok, Tayfur

    2007-01-01

    Simulation Modeling and Analysis with Arena is a highly readable textbook which treats the essentials of the Monte Carlo discrete-event simulation methodology, and does so in the context of a popular Arena simulation environment.” It treats simulation modeling as an in-vitro laboratory that facilitates the understanding of complex systems and experimentation with what-if scenarios in order to estimate their performance metrics. The book contains chapters on the simulation modeling methodology and the underpinnings of discrete-event systems, as well as the relevant underlying probability, statistics, stochastic processes, input analysis, model validation and output analysis. All simulation-related concepts are illustrated in numerous Arena examples, encompassing production lines, manufacturing and inventory systems, transportation systems, and computer information systems in networked settings.· Introduces the concept of discrete event Monte Carlo simulation, the most commonly used methodology for modeli...

  8. Application of fire PSA in enhancing NPP safety: a case study with Indian PHWRS

    International Nuclear Information System (INIS)

    Fire PSA (Probabilistic Safety Assessment) is the probabilistic analysis of fire events and their potential impact on the safety of a Nuclear Power Plant (NPP). Using probabilistic models, the fire PSA takes into account the possibility of a fire at specific plant locations and its propagation, detection and suppression of the fire; and also helps to assess the effect of the fire on safety related cables and equipment. Typically, Fire PSA involves five stages of analysis: Screening Analysis, Fire Hazard Analysis, Fire Frequency Analysis, Fire Propagation Analysis and System analysis. The probabilistic criteria used in fire PSA are based on the risk concept. Core damage frequency is a typical criterion used for PSA Level 1. Fire PSA relies on the plant response model developed for the internal initiating events. The availability of a plant model that logically examines the contributions to core damage is a prerequisite for a fire PSA. It should be pointed out that extending an internal event PSA to a fire PSA requires a considerable amount of plant specific data, such as the location of cable routes in plant compartments, fire barriers etc. The detailed fire PSA analyses was carried out for a typical Indian Nuclear Power Plant. Fire fighting system for the NPP under consideration was designed based on the prevailing standards for fire safety design. These provisions were critically analysed (after appropriate screening of fire critical areas) by using codes such as COMPBRN IIIe and Fire Dynamics Simulator (FDS). Based on the results of these studies, activities such as installation of fire barriers at critical locations, re-routing of redundant safety related cables, etc. were carried out for reducing the fire contribution to CDF. Also, suitable provisions were identified to prevent occurrence of possible core damage scenario as pointed in Fire PSA study. After retrofitting, fire PSA was re-done to quantify and ensure the reduction in the contribution of the CDF

  9. A coupled thermo-hygro-chemo-mechanical model for the simulation of spalling of concrete subjected to fire loading

    Directory of Open Access Journals (Sweden)

    Zeiml M.

    2013-09-01

    Full Text Available The presented research work contributes to the realistic simulation of the stress state within fire-loaded concrete in order to attain insight into the development and occurrence of the critical state right before and during the event of spalling. A coupled thermo-hygro-chemo-mechanical code simulating the stress state as a consequence of both thermo-hygral and thermo-mechanical processes is presented together with an embedded strong-discontinuity model which is capable of capturing and tracking the propagation of a crack evolving in concrete as a quasi-brittle material. Combination of the two mentioned models is currently under way. With the resulting coupled model, it will be possible to take into account all major couplings, allowing to realistically simulate the spalling process.

  10. Smoke injection heights from fires in North America: analysis of 5 years of satellite observations

    Directory of Open Access Journals (Sweden)

    M. Val Martin

    2009-09-01

    Full Text Available We analyze a multi-year record of aerosol smoke plume heights derived from observations over North America made by the Multi-angle Imaging SpectroRadiometer (MISR instrument on board the NASA Earth Observing System Terra satellite. We characterize the magnitude and variability of smoke plume heights for various biomes, and assess the contribution of local atmospheric and fire conditions to this variability. Plume heights are highly variable, ranging from a few hundred meters up to 5000 m above the terrain at the Terra overpass time (11:00–14:00 local time. The largest plumes are found over the boreal region (median values of ∼850 m height, 24 km length and 940 m thickness, whereas the smallest plumes are found over cropland and grassland fires in the contiguous US (median values of ∼530 m height, 12 km length and 550–640 m thickness. The analysis of plume heights in combination with assimilated meteorological observations from the NASA Goddard Earth Observing System indicates that a significant fraction (4–12% of plumes from fires are injected above the boundary layer (BL, consistent with earlier results for Alaska and the Yukon Territories during summer 2004. Most of the plumes located above the BL (>83% are trapped within stable atmospheric layers. We find a correlation between plume height and the MODerate resolution Imaging Spectroradiometer (MODIS fire radiative power (FRP thermal anomalies associated with each plume. Smoke plumes located in the free troposphere (FT exhibit larger FRP values (1620–1640 MW than those remaining within the BL (174–465 MW. Plumes located in the FT without a stable layer reach higher altitudes and are more spread-out vertically than those associated with distinct stable layers (2490 m height and 2790 m thickness versus 1880 m height and 1800 thickness. The MISR plume climatology exhibits a well-defined seasonal cycle of plume heights in boreal and temperate biomes, with greater heights during June

  11. Evaluation Result of PIRT Methodology for Fire Modeling

    International Nuclear Information System (INIS)

    One of sensitive items for the fire risk analysis with fire models is the major effect of input data to modeling result. If input factors are influential to the output of the program, their reliability must be appraised at the initial stage of design. In addition to the importance of input data, modeling itself should be reviewed by the verification and validation process. As shown in NUREG-1824, EPRI and NRC already verified the mathematical solution of the governing equations for CFAST and FDS. However, the validation of fire modeling must be done to quantify uncertainties originated from the physical approximation and immature capabilities of the program designer. A way to reduce uncertainties of fire modeling is to compare the predicted values by fire models and the experimental results.One of the ways to upgrade the fire modeling credibility is to find out what sort of phenomenon is important at fire scenarios and how much the fire model is adequate to the real fire situations. In this purpose, we studied PIRT to apply to fire modeling tools and PIRT means Phenomena Identification Ranking Table which has been used to assess the code scaling, applicability, and uncertainty (CSAU) by NRC. When fire models are used to simulate the real fire situation, it is important to identify the critical input data and effective factors to modeling output. At this study, it was confirmed that the fire modeling in NPPs can be implemented by the representative six types of fire scenarios and major fire phenomena which was originated from the baseline fire scenarios. The expert panel also determined the most important sub-phenomenon of fire in major fire situation. One of most valuable output at this study is the list of ranking table for the key parameters. By use of this result, the fire modeling practices in NPPs can be more upgraded with enhanced credibility

  12. Does Suspected Sleep Disordered Breathing Impact on the Sleep and Performance of Firefighting Volunteers during a Simulated Fire Ground Campaign?

    Directory of Open Access Journals (Sweden)

    Sarah M. Jay

    2016-01-01

    Full Text Available Adequate sleep is fundamental to workplace performance. For volunteer firefighters who work in safety critical roles, poor performance at work can be life threatening. Extended shifts and sleeping conditions negatively impact sleep during multi-day fire suppression campaigns. Having sleep disordered breathing (SDB could contribute further to sleep deficits. Our aim was to investigate whether those with suspected SDB slept and performed more poorly during a fire ground simulation involving sleep restriction. Participants, n = 20 participated in a 3-day-4-night fire ground simulation. Based on oximetry desaturation index data collected during their participation, participants were retrospectively allocated to either a SDB (n = 8 or a non-SDB group (n = 12. The simulation began with an 8 h Baseline sleep (BL followed by two nights of restricted (4 h sleep and an 8 h recovery sleep (R. All sleeps were recorded using a standard electroencephalography (EEG montage as well as oxygen saturation. During the day, participants completed neurobehavioral (response time, lapses and subjective fatigue tasks. Mixed effects ANOVA were used to compare differences in sleep and wake variables. Analyses revealed a main effect of group for Total sleep (TST, REM , wake after sleep onset (WASO and Arousals/h with the SDB group obtaining less TST and REM and greater WASO and Arousals/h. The group × night interaction was significant for N3 with the SDB group obtaining 42 min less during BL. There was a significant main effect of day for RRT, lapses and subjective fatigue and a significant day × group interaction for RRT. Overall, the SDB group slept less, experienced more disturbed sleep and had poorer response time performance, which was exacerbated by the second night of sleep restriction. This could present a safety concern, particularly during longer campaigns and is worthy of further investigation. In addition, we would recommend promotion of awareness of SDB, its

  13. Does Suspected Sleep Disordered Breathing Impact on the Sleep and Performance of Firefighting Volunteers during a Simulated Fire Ground Campaign?

    Science.gov (United States)

    Jay, Sarah M; Smith, Bradley P; Windler, Samantha; Dorrian, Jillian; Ferguson, Sally A

    2016-02-01

    Adequate sleep is fundamental to workplace performance. For volunteer firefighters who work in safety critical roles, poor performance at work can be life threatening. Extended shifts and sleeping conditions negatively impact sleep during multi-day fire suppression campaigns. Having sleep disordered breathing (SDB) could contribute further to sleep deficits. Our aim was to investigate whether those with suspected SDB slept and performed more poorly during a fire ground simulation involving sleep restriction. Participants, n = 20 participated in a 3-day-4-night fire ground simulation. Based on oximetry desaturation index data collected during their participation, participants were retrospectively allocated to either a SDB (n = 8) or a non-SDB group (n = 12). The simulation began with an 8 h Baseline sleep (BL) followed by two nights of restricted (4 h) sleep and an 8 h recovery sleep (R). All sleeps were recorded using a standard electroencephalography (EEG) montage as well as oxygen saturation. During the day, participants completed neurobehavioral (response time, lapses and subjective fatigue) tasks. Mixed effects ANOVA were used to compare differences in sleep and wake variables. Analyses revealed a main effect of group for Total sleep (TST), REM , wake after sleep onset (WASO) and Arousals/h with the SDB group obtaining less TST and REM and greater WASO and Arousals/h. The group × night interaction was significant for N3 with the SDB group obtaining 42 min less during BL. There was a significant main effect of day for RRT, lapses and subjective fatigue and a significant day × group interaction for RRT. Overall, the SDB group slept less, experienced more disturbed sleep and had poorer response time performance, which was exacerbated by the second night of sleep restriction. This could present a safety concern, particularly during longer campaigns and is worthy of further investigation. In addition, we would recommend promotion of awareness of SDB, its symptoms

  14. Fire simulation in large compartments with a fire model 'FDS'. Part 3. Accuracy evaluation of pyrolysis rate of liquid combustible and wall heat transfer

    International Nuclear Information System (INIS)

    The accuracy of a fire model, FDS, were evaluated for a fire plume developed from combustible liquid and a natural convection from a high-temperature vertical wall, focusing on pyrolysis rate of combustibles and heat transfer coefficient of walls, both of which greatly affect the accuracy of air temperature in compartment fires. For a fire plume, numerical results with the submodel 'Liquid' predicting pyrolysis of combustible liquid largely depend on grid spacing and have a margin of error of approximately twenty percent at minimum in heat release rate (HRR). Thus, the submodel 'Specified HRR' prescribing the pyrolysis should be more effective when HRR is known in postulated fires. Concerning grid spacing for accurately predicting a fire plume, the condition of Δ < D*/20 (D*: characteristic fire size, Δ: grid spacing) for a combustible-gas fire plume could be applied to a combustible-liquid fire plume. For a natural convection from a wall, an empirical submodel of heat transfer coefficient was nearly independent of grid spacing, and gave the good predictions for turbulent heat transfer. Unsteady flows near walls were also predicted on the grid-spacing condition of Δη < approximately 0.6 (η: similarity variable for laminar boundary layer), although their accuracy was much lower than that of the heat transfer coefficient. (author)

  15. Forest fire propagation simulations for a risk assessment methodology development for a nuclear power plant

    Directory of Open Access Journals (Sweden)

    Yasushi Okano

    2015-10-01

    Given that this study shows that the maximum height of a flame on a canopy top is close to the range of power line height, a loss of offsite power is recognized as a possible subsequent event during a forest fire.

  16. High temperature corrosion under conditions simulating biomass firing: depth-resolved phase identification

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming; Pantleon, Karen

    2014-01-01

    ) were coated with KCl and is o-thermally exposed at 560 o C for 168 h under a flue gas corresponding to straw firing. Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and X-ray Diffraction (XRD) characterization techniques were employed for comprehensive characterization of the...

  17. Directional excitation of Rg due to ripple-fired explosions: 2-Dimensional finite-difference simulations

    International Nuclear Information System (INIS)

    A major issue for the Non-Proliferation Treaty is the discrimination of large chemical explosions from possible clandestine or small nuclear tests. Unless discrimination is possible, the numerous mining blasts could give ample opportunity for concealing clandestine tests. Ripple-fired explosions are commonly used to fragment rocks during quarry and open-pit mining. The periodicity inherent in the ripple firing could produce a seismic reinforcement at the frequency of the delay between shots or rows. It has been suggested that the convolution of a single explosion with a comb function of variable spacing and variable amplitude can be used to model the distinctive signature of ripple firing. Baumgardt and Ziegler (1988) delicately demonstrated that the incoherent array-stack spectra can be used to identify some multiple shots recorded at NORSAR. By superpositioning the waveform due to a single shot with proper time delay, they were able to model the source multiplicity under the assumption that the spatial spreading of the shots is negligible with respect to the distance to the receiver. The work by Stump et al. successfully characterized the major features of the wavefield due to ripple firings at near-source ranges

  18. Advanced concept for damage control : A framework to simulate fire propagation and damage control effects

    NARCIS (Netherlands)

    Gillis, M.P.W.; Keijer, W.; Smit, C.S.

    2003-01-01

    Current damage control procedures are developed on the basis of a long-standing experience. However there are reasons to believe that these procedures do not account for major weapon-induced calamities. Fire fighting after substantial blast and fragmentation damage, due to a weaponhit, is quite beyo

  19. Fire and simulated herbivory have antagonistic effects on resistance of savanna grasslands to alien shrub invasion

    NARCIS (Netherlands)

    te Beest, Mariska; Mpandza, Nokukhanya J.; Olff, Han

    2015-01-01

    Question Resistance of the native community has been identified as an important factor limiting invasion success and invader impact. However, to what extent resistance interacts with disturbance to control invasion success remains unclear. We studied the interaction between biotic resistance, fire a

  20. Smoke simulation for fire engineering using a multigrid method on graphics hardware

    DEFF Research Database (Denmark)

    Glimberg, Stefan; Erleben, Kenny; Bennetsen, Jens

    We present a GPU-based Computational Fluid Dynamics solver for the purpose of fire engineering. We apply a multigrid method to the Jacobi solver when solving the Poisson pressure equation, supporting internal boundaries. Boundaries are handled on the coarse levels, ensuring that boundaries will n...

  1. Simulating effects of fire disturbance and climate change on boreal forest productivity and evapotranspiration

    International Nuclear Information System (INIS)

    We used a terrestrial ecosystem process model, BIOME-BGC, to investigate historical climate change and fire disturbance effects on regional carbon and water budgets within a 357,500 km2 portion of the Canadian boreal forest. Historical patterns of increasing atmospheric CO2, climate change, and regional fire activity were used as model drivers to evaluate the relative effects of these impacts to spatial patterns and temporal trends in forest net primary production (NPP) and evapotranspiration (ET). Historical trends of increasing atmospheric CO2 resulted in overall 13% and 5% increases in annual NPP and ET from 1994 to 1996, respectively. NPP was found to be relatively sensitive to changes in air temperature (Ta), while ET was more sensitive to precipitation (P) change within the ranges of observed climate variability (e.g., +/-2 oC for Ta and +/-20% for P). In addition, the potential effect of climate change related warming on NPP is exacerbated or offset depending on whether these changes are accompanied by respective decreases or increases in precipitation. Historical fire activity generally resulted in reductions of both NPP and ET, which consumed an average of approximately 6% of annual NPP from 1959 to 1996. Areas currently occupied by dry conifer forests were found to be subject to more frequent fire activity, which consumed approximately 8% of annual NPP. The results of this study show that the North American boreal ecosystem is sensitive to historical patterns of increasing atmospheric CO2, climate change and regional fire activity. The relative impacts of these disturbances on NPP and ET interact in complex ways and are spatially variable depending on regional land cover and climate gradients. (author)

  2. Modeling and numerical analysis of granite rock specimen under mechanical loading and fire

    Directory of Open Access Journals (Sweden)

    Luc Leroy Ngueyep. Mambou

    2015-02-01

    Full Text Available The effect of ISO 834 fire on the mechanical properties of granite rock specimen submitted to uniaxial loading is numerically investigated. Based on Newton's second law, the rate-equation model of granite rock specimen under mechanical load and fire is established. The effect of heat treatment on the mechanical performance of granite is analyzed at the center and the ends of specimen. At the free end of granite rock specimen, it is shown that from 20 °C to 500 °C, the internal stress and internal strain are weak; whereas above 500 °C, they start to increase rapidly, announcing the imminent collapse. At the center of specimen, the analysis of the internal stress and internal strain reveals that the fire reduces the mechanical performance of granite significantly. Moreover, it is found that after 3 min of exposure to fire, the mechanical energy necessary to fragment the granite can be reduced up to 80%.

  3. Assessing evidentiary value in fire debris analysis by chemometric and likelihood ratio approaches.

    Science.gov (United States)

    Sigman, Michael E; Williams, Mary R

    2016-07-01

    Results are presented from support vector machine (SVM), linear and quadratic discriminant analysis (LDA and QDA) and k-nearest neighbors (kNN) methods of binary classification of fire debris samples as positive or negative for ignitable liquid residue. Training samples were prepared by computationally mixing data from ignitable liquid and substrate pyrolysis databases. Validation was performed on an unseen set of computationally mixed (in silico) data and on fire debris from large-scale research burns. The probabilities of class membership were calculated using an uninformative (equal) prior and a likelihood ratio was calculated from the resulting class membership probabilities. The SVM method demonstrated a high discrimination, low error rate and good calibration for the in silico validation data; however, the performance decreased significantly for the fire debris validation data, as indicated by a significant increase in the error rate and decrease in the calibration. The QDA and kNN methods showed similar performance trends. The LDA method gave poorer discrimination, higher error rates and slightly poorer calibration for the in silico validation data; however the performance did not deteriorate for the fire debris validation data. PMID:27081767

  4. 氢气喷射火的大涡模拟%Large Eddy Simulation of Hydrogen Jet Fire

    Institute of Scientific and Technical Information of China (English)

    付佳佳; 王昌建; 秦俊; 李建

    2013-01-01

    基于OpenFOAM平台,嵌入基于大涡模拟思想的涡耗散概念燃烧模型改进的fvDOM辐射计算模型,采用氢单步化学反应模型来计算细结构的反应速率。对不同喷射速度和喷口直径的低速氢喷射火进行模拟。结果表明,采用该计算模型获得的火焰高度与理论预测值基本一致;随着氢喷射速度的增大,火焰高度增加,喷射火最高温度降低,但最高温度点的位置上升;随着氢喷口直径增大,火焰高度增加,最高温度点的位置上移,但火焰最高温度基本维持不变。%Within OpenFOAM toolbox,eddy dissipation concept in LES framework and modified fvDOM radiation model were taken into account,in conjunction with hydrogen-air single-step chemistry model for approaching reac-tion rate in the fine structure. Then the jet fires were simulated with varying inlet velocity and nozzle diameters. The results show that the calculated fire heights agree well those theoretically predicted. With the increase of hydrogen jet velocity,fire height increases,with the peak temperature decreases with its location elevated. With the increase of nozzle diameter,fire height increases,the peak temperature location is elevated,but the peak temperature remains almost unchangeable.

  5. A new firing paradigm for integrate and fire stochastic neuronal models.

    Science.gov (United States)

    Sirovich, Roberta; Testa, Luisa

    2016-06-01

    A new definition of firing time is given in the framework of Integrate and Fire neuronal models. The classical absorption condition at the threshold is relaxed and the firing time is defined as the first time the membrane potential process lies above a fixed depolarisation level for a sufficiently long time. The mathematical properties of the new firing time are investigated both for the Perfect Integrator and the Leaky Integrator. In the latter case, a simulation study is presented to complete the analysis where analytical results are not yet achieved. PMID:27106182

  6. Three-dimensional rail cooling analysis for a repetitively fired railgun

    International Nuclear Information System (INIS)

    This paper reports on a three-dimensional (3-D) rail cooling analysis for fabrication and demonstration of a stand-alone repetitive fire compulsator driven 9 MJ gun system which has been performed to assure the entire rail can be maintained below its thermal limit for multiple shots. The 3-D rail thermal model can predict the temperature, pressure, and convective heat transfer coefficient variations of the coolant along the 10 m long copper rail. The 9-MJ projectiles will be fired every 20 s for 3 min. Water cooling was used in the model for its high cooling capacity. Single liquid phase heat transfer was assumed in the cooling analysis. For multiple shots, the temperature difference between the rail and the water was enhanced due to accumulated heat in the rail. As a result, the heat removal by water increased from shot-to-shot. The rail temperature initially increased and finally stabilized after a number of shots

  7. Agent-Based Evacuation Model Incorporating Fire Scene and Building Geometry

    Institute of Scientific and Technical Information of China (English)

    TANG Fangqin; REN Aizhu

    2008-01-01

    A comprehensive description of the key factors affecting evacuations at fire scones is necessary for accurate simulations.An agent-based simulation model which incorporates the fire scene and the building geometry is developed using a fire dynamics simulator (FDS) based on the computational fluid dynamics and geographic information system (GIS) data to model the occupant response.The building entities are generated for FDS simulation while the spatial analysis on GIS data represents the occupant's knowledge of the building.The influence of the fire is based on a hazard assessment of the combustion products.The agent behavior and decisions are affected by environmental features and the fire field.A case study demonstrates that the evacuation model effectively simulates the coexistence and interactions of the major factors including occupants,building geometry,and fire disaster during the evacuation.The results can be used for the assessments of building designs regarding fire safety.

  8. A qualitative analysis of future air combat with 'fire and forget' missiles

    Science.gov (United States)

    Shinar, J.; Davidovitz, A.

    1987-01-01

    A set of previous examples have demonstrated that the two-target game formulation is adequate for modeling air-to-air combat between two aggressively motivated fighter aircraft. The present paper describes such an engagement between two aircraft of different speed but equipped with the same 'fire and forget' type guided missiles. The results of the analysis suggest a new concept of air combat tactics for future scenarios.

  9. Performance Analysis of a Coal-Fired External Combustion Compressed Air Energy Storage System

    OpenAIRE

    Wenyi Liu; Qing Li; Feifei Liang; Linzhi Liu; Gang Xu; Yongping Yang

    2014-01-01

    Compressed air energy storage (CAES) is one of the large-scale energy storage technologies utilized to provide effective power peak load shaving. In this paper, a coal-fired external combustion CAES, which only uses coal as fuel, is proposed. Unlike the traditional CAES, the combustion chamber is substituted with an external combustion heater in which high-pressure air is heated before entering turbines to expand in the proposed system. A thermodynamic analysis of the proposed CAES is conduct...

  10. Ash fouling monitoring and key variables analysis for coal fired power plant boiler

    OpenAIRE

    Shi Yuanhao; Wang Jingcheng

    2015-01-01

    Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process...

  11. Experimental analysis of a combustion reactor under co-firing coal with biomass

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Fabyo Luiz; Bazzo, Edson; Oliveira Junior, Amir Antonio Martins de [Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil). LabCET], e-mail: ebazzo@emc.ufsc.br; Bzuneck, Marcelo [Tractebel Energia S.A., Complexo Termeletrico Jorge Lacerda, Capivari de Baixo, SC (Brazil)], e-mail: marcelob@tractebelenergia.com.br

    2010-07-01

    Mitigation of greenhouse gases emission is one of the most important issues in energy engineering. Biomass is a potential renewable source but with limited use in large scale energy production because of the relative smaller availability as compared to fossil fuels, mainly to coal. Besides, the costs concerning transportation must be well analysed to determine its economic viability. An alternative for the use of biomass as a primary source of energy is the co-firing, that is the possibility of using two or more types of fuels combined in the combustion process. Biomass can be co-fired with coal in a fraction between 10 to 25% in mass basis (or 4 to 10% in heat-input basis) without seriously impacting the heat release characteristics of most boilers. Another advantage of cofiring, besides the significant reductions in fossil CO{sub 2} emissions, is the reduced emissions of NO{sub x} and SO{sub x}. As a result, co-firing is becoming attractive for power companies worldwide. This paper presents results of some experimental analysis on co-firing coal with rice straw in a combustion reactor. The influence of biomass thermal share in ash composition is also discussed, showing that alkali and earth alkaline compounds play the most important role on the fouling and slagging behavior when co-firing. Some fusibility correlations that can assist in the elucidation of these behavior are presented and discussed, and then applied to the present study. Results show that for a biomass thermal share up to 20%, significant changes are not expected in fouling and slagging behavior of ash. (author)

  12. Proteome analysis of the liver in the Chinese fire-bellied newt Cynops orientalis.

    Science.gov (United States)

    Zang, X Y; Guo, J L; Geng, X F; Li, P F; Sun, J Y; Wang, Q W; Xu, C S

    2016-01-01

    The Chinese fire-bellied newt, Cynops orientalis, belonging to Amphibia, Caudata, Salamandridae is a species endemic to China. The liver, which is an important digestive gland and the largest amphibian organ, has various functions, including detoxification, glycogen storage, protein synthesis, and hormone production. However, the newt liver has rarely been studied at the molecular level. We performed histomorphology and high-throughput proteomic analysis of the Chinese fire-bellied newt liver, using hematoxylin and eosin (H&E) staining and two-dimensional electrophoresis coupled with mass spectrometry. The H&E staining showed that the newt liver nuclei are large and round, are located in the lateral cytoplasm, and contain a large quantity of lipid droplets. Melanins were abundantly present throughout the hepatic parenchyma. The proteome analysis showed a total of 545 proteins detected in the newt liver. Furthermore, a gene ontology analysis suggested that these proteins were associated with metabolism, immune response, cellular homeostasis, etc. Among these, proteins with metabolic functions were found to be the most abundant and highly expressed. This supports the role of the liver as the metabolic center. The proteomic results provide new insights into the aspects of the liver proteomes of the Chinese fire-bellied newt. The identification of a more global liver proteome in the newt may provide a basis for characterizing and comparing the liver proteomes from other amphibian species. PMID:27525932

  13. Fire and simulated herbivory have antagonistic effects on resistance of savanna grasslands to alien shrub invasion

    OpenAIRE

    te Beest, Mariska; Mpandza, Nokukhanya J.; Olff, Han

    2015-01-01

    Question Resistance of the native community has been identified as an important factor limiting invasion success and invader impact. However, to what extent resistance interacts with disturbance to control invasion success remains unclear. We studied the interaction between biotic resistance, fire and small-scale disturbances mimicking those of large mammalian herbivores (hoof action and grazing) on invasion success of the alien shrub Chromolaena odorata. Location Hluhluwe-iMfolozi Park, Sout...

  14. Project Flambeau experimental fire measurements

    International Nuclear Information System (INIS)

    This preliminary analysis and model formulation of the Project Flambeau fires taken together with other information, seems to indicate that mass fires and conflagrations are three-dimensional and oscillatory in nature. Large areas fires seem to naturally fall into a strong fire generated vortices. The vortices oscillated with a period of about 50 seconds in these fires

  15. Fire exposure testing of encapsulated simulant radioactive wastes. Task 3 characterization of radioactive waste forms a series of final reports (1985-89) no. 13

    International Nuclear Information System (INIS)

    There are no regulations in the UK or elsewhere in the EC that deal specifically with storage fire accident criteria for ILWs. In order to establish such criteria and develop test methods it is pertinent to provide data on the behaviour of typical waste packages in severe fire accidents. This programme seeks to provide information on the performance of a range of waste types using full-scale non-radioactive simulated packaged wasteforms. The initial objective is to identify the test conditions for packages, which will allow interpolation of results rather than extrapolation, for fires in which drums of waste are directly exposed to a hydrocarbon pool fire, and those in which packages are in their transport overpacks leading to significantly lower heat fluxes. These conditions provide the experimental parameters for the execution of thermal tests to measure the performance of full-scale packages. This testwork can be split into two distinct categories: (a) Furnace test, representing a transport fire. In transport, drums are placed within an overpack that performs the function of a thermal barrier protecting the drums during a fire. (b) Pool fire test, which simulates the fire conditions which bare drums could be subjected to in storage. A theoretical model already exists in rough form which predicts wasteform temperature profiles and steam release rates from immobilized waste, the results from this programme of work will enable the modellers at Harwell to develop and validate this model and consequently predict both the gaseous and particulate, transport and release mechanisms from the waste matrix which may be encountered in fire accident conditions. This programme is being conducted in parallel and in close liaison with small-scale fully active studies at AERE Harwell under the CEC contract. 45 figs.; 5 tabs

  16. Response Predicting LTCC Firing Shrinkage: A Response Surface Analysis Study

    Energy Technology Data Exchange (ETDEWEB)

    Girardi, Michael; Barner, Gregg; Lopez, Cristie; Duncan, Brent; Zawicki, Larry

    2009-02-25

    The Low Temperature Cofired Ceramic (LTCC) technology is used in a variety of applications including military/space electronics, wireless communication, MEMS, medical and automotive electronics. The use of LTCC is growing due to the low cost of investment, short development time, good electrical and mechanical properties, high reliability, and flexibility in design integration (3 dimensional (3D) microstructures with cavities are possible)). The dimensional accuracy of the resulting x/y shrinkage of LTCC substrates is responsible for component assembly problems with the tolerance effect that increases in relation to the substrate size. Response Surface Analysis was used to predict product shrinkage based on specific process inputs (metal loading, layer count, lamination pressure, and tape thickness) with the ultimate goal to optimize manufacturing outputs (NC files, stencils, and screens) in achieving the final product design the first time. Three (3) regression models were developed for the DuPont 951 tape system with DuPont 5734 gold metallization based on green tape thickness.

  17. Firing the furnace? An econometric analysis of utilities' fuel choice

    International Nuclear Information System (INIS)

    This paper attempts to estimate how the fuel mix of German electricity producers does react to fuel price changes. The empirical analysis is based on panel data (1968-1998) of major utilities. Two different aspects of fuel choice are distinguished: at the one hand, the construction of usually fuel-specific capacities for electric power generation, i.e. investment decisions that determine the fuel mix in the long run; at the other, fuel use conditional on existing generation capacities, i.e. short-run inter-fuel substitution. According to the results from panel unit root tests, both the econometric models which describe these two aspects are specified in changes rather than levels. The partly discrete nature of investment decisions is taken into account, by constructing a discrete model of capacity adjustment. Our estimation results suggest that the fuel mix of electric utilities is price inelastic either if long-term investment or short-term inter-fuel substitution is considered. Finally, the empirical results are used to predict the potential impacts of CO2 emissions trading on fuel choice in the German electric power industry. (Author)

  18. Firing the furnace? An econometric analysis of utilities' fuel choice

    International Nuclear Information System (INIS)

    This paper attempts to estimate how the fuel mix of German electricity producers does react to fuel price changes. The empirical analysis is based on panel data (1968-1998) of major utilities. Two different aspects of fuel choice are distinguished: at the one hand, the construction of usually fuel-specific capacities for electric power generation, i.e. investment decisions that determine the fuel mix in the long run; at the other, fuel use conditional on existing generation capacities, i.e. short-run inter-fuel substitution. According to the results from panel unit root tests, both the econometric models which describe these two aspects are specified in changes rather than levels. The partly discrete nature of investment decisions is taken into account, by constructing a discrete model of capacity adjustment. Our estimation results suggest that the fuel mix of electric utilities is price inelastic either if long-term investment or short-term inter-fuel substitution is considered. Finally, the empirical results are used to predict the potential impacts of CO2 emissions trading on fuel choice in the German electric power industry

  19. Analysis of Post-Fire Vegetation Recovery in the Mediterranean Basin using MODIS Derived Vegetation Indices

    Science.gov (United States)

    Hawtree, Daniel; San Miguel, Jesus; Sedano, Fernando; Kempeneers, Pieter

    2010-05-01

    The Mediterranean basin region is highly susceptible to wildfire, with approximately 60,000 individual fires and half a million ha of natural vegetation burnt per year. Of particular concern in this region is the impact of repeated wildfires on the ability of natural lands to return to a pre-fire state, and of the possibility of desertification of semi-arid areas. Given these concerns, understanding the temporal patterns of vegetation recovery is important for the management of environmental resources in the region. A valuable tool for evaluating these recovery patterns are vegetation indices derived from remote sensing data. Previous research on post-fire vegetation recovery conducted in this region has found significant variability in recovery times across different study sites. It is unclear what the primary variables are affecting the differences in the rates of recovery, and if any geographic patterns of behavior exist across the Mediterranean basin. This research has primarily been conducted using indices derived from Landsat imagery. However, no extensive analysis of vegetation regeneration for large regions has been published, and assessment of vegetation recovery on the basis of medium-spatial resolution imagery such as that of MODIS has not yet been analyzed. This study examines the temporal pattern of vegetation recovery in a number of fire sites in the Mediterranean basin, using data derived from MODIS 16 -day composite vegetation indices. The intent is to develop a more complete picture of the temporal sequence of vegetation recovery, and to evaluate what additional factors impact variations in the recovery sequence. In addition, this study evaluates the utility of using MODIS derived vegetation indices for regeneration studies, and compares the findings to earlier studies which rely on Landsat data. Wildfires occurring between the years 2000 and 2004 were considered as potential study sites for this research. Using the EFFIS dataset, all wildfires

  20. Simulation Data Analysis Using Fuzzy Graphs

    OpenAIRE

    Huber, Klaus-Peter; MICHAEL R BERTHOLD

    2006-01-01

    Analysis of simulation models has gained considerable interest in the past. However, their complexity still remains a considerable drawback in practical applications. A promising concept is to analyze the data from simulation experiments. Existing approaches are either restricted to simple models or are hard to interpret. We present an efficient algorithm that constructs a fuzzy graph model from simulation data and we show that the resulting system approximates also complex model functions wi...

  1. Co-firing coal with wood pellets for U.S. electricity generation: A real options analysis

    International Nuclear Information System (INIS)

    In contrast to EU, U.S. electric utilities are not employing the bioenergy technology of co-firing wood pellets with coal. This difference in employment patterns is explored within a real options analysis (ROA) for possible U.S. utilization of wood pellets, considering fuel-price series from 2009 to 2014. For analysis, these series are divided into two sub-periods based on different market conditions: Infancy (2009–2011) and Substitution (2012–2014). ROA indicates co-firing wood pellets with coal is feasible considering adoption during wood pellets' infancy, under low discount rates, and long power-plant lifespans. A portfolio effect of employing multiple fuels underlies this result. However, co-firing is not currently economically feasible. The different adoption decisions are likely a consequence of recent cheap and abundant U.S. natural gas. For co-fired wood pellets to be feasible, government incentives and/or a market increase in natural gas prices appear necessary. -- Highlights: •Real options analysis indicates co-firing is not currently economically feasible within the U.S. •The recent U.S. natural-gas boom is likely hindering the adoption of co-firing. •For co-fired adoption, government incentives or an increase in natural-gas prices are necessary

  2. Identifying past fire regimes throughout the Holocene in Ireland using new and established methods of charcoal analysis

    Science.gov (United States)

    Hawthorne, Donna; Mitchell, Fraser J. G.

    2016-04-01

    Globally, in recent years there has been an increase in the scale, intensity and level of destruction caused by wildfires. This can be seen in Ireland where significant changes in vegetation, land use, agriculture and policy, have promoted an increase in fires in the Irish landscape. This study looks at wildfire throughout the Holocene and draws on lacustrine charcoal records from seven study sites spread across Ireland, to reconstruct the past fire regimes recorded at each site. This work utilises new and accepted methods of fire history reconstruction to provide a recommended analytical procedure for statistical charcoal analysis. Digital charcoal counting was used and fire regime reconstructions carried out via the CharAnalysis programme. To verify this record new techniques are employed; an Ensemble-Member strategy to remove the objectivity associated with parameter selection, a Signal to Noise Index to determine if the charcoal record is appropriate for peak detection, and a charcoal peak screening procedure to validate the identified fire events based on bootstrapped samples. This analysis represents the first study of its kind in Ireland, examining the past record of fire on a multi-site and paleoecological timescale, and will provide a baseline level of data which can be built on in the future when the frequency and intensity of fire is predicted to increase.

  3. Thermodynamic analysis of an existing coal-fired power plant for district heating/cooling application

    International Nuclear Information System (INIS)

    In a conventional coal-fired power plant, which is only designed for electricity generation, 2/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating/cooling demand of their locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired power plant, which is designed only for electricity generation, has been carried out. Waste heat potentials and other heat extraction capabilities have been evaluated. Best effective steam extraction point for district heating/cooling system; have been identified by conducting energetic and exergetic performance analyses. Analyses results revealed that the low-pressure turbine inlet stage is the most convenient point for steam extraction for the plant analyzed.

  4. Thermodynamic analysis of an existing coal-fired power plant for district heating/cooling application

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, H.H.; Dagdas, A.; Sevilgen, S.H.; Cetin, B.; Akkaya, A.V.; Sahin, B.; Teke, I.; Gungor, C.; Atas, S. [Yildiz Technical University, Istanbul (Turkey). Dept. of Mechanical Engineering

    2010-02-15

    In a conventional coal-fired power plant, which is only designed for electricity generation, 2/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating/cooling demand of the locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired power plant, which is designed only for electricity generation, has been carried out. Waste heat potential and other heat extraction capabilities have been evaluated. Best effective steam extraction point for district heating/cooling systems have been identified by conducting energetic and exergetic performance analyses. Analyses results revealed that the low-pressure turbine inlet stage is the most convenient point for steam extraction for the plant analyzed.

  5. Improving analytic hierarchy process applied to fire risk analysis of public building

    Institute of Scientific and Technical Information of China (English)

    SHI Long; ZHANG RuiFang; XIE QiYuan; FU LiHua

    2009-01-01

    The structure importance in Fault Tree Analysis (FTA) reflects how important Basic Events are to Top Event.Attribute at alternative level in Analytic Hierarchy Process (AHP) also reflect its importance to general goal.Based on the coherence of these two methods,an improved AHP is put forward.Using this improved method,how important the attribute is to the fire safety of public building can be ana-lyzed more credibly because of the reduction of subjective judgment.Olympic venues are very impor-tant public buildings in China.The fire safety evaluation of them will be a big issue to engineers.Im-proved AHP is a useful tool to the safety evaluation to these Olympic venues,and it will guide the evaluation in other areas.

  6. Determination of skin temperature distribution and heat flux during simulated fires using Green's functions over finite-length scales

    International Nuclear Information System (INIS)

    One of the current practices for measuring heat flux during flash fire testing, forest fires, and other industrial cases focuses on the use of semi-infinite models to predict the heat flux during exposure through surface temperature measurements on simulated skin sensors. For short time frames, these models can be shown to have acceptable accuracy. However, when considering longer time exposures at reduced heat fluxes, such as with firefighters in a forest fire, the accuracy of these models could be brought into question. A one-dimensional, finite length scale, transient heat conduction model was developed using a Green's function approach on a rectangular sensor. The model was developed using transient temperature boundary conditions to avoid the use of complicated radiation and convection conditions at each boundary. For comparison, a semi-infinite model utilizing the same boundary condition on the exposed face was solved using both the Laplace transform method and Green's function method. Experimental data was obtained during exposure to a cone calorimeter. All measurements were taken for a minimum duration of 2 min. This temperature data was used to develop appropriate curves for the boundary conditions and validate the analytical models. It was found that the temperature obtained from the one-dimensional transient heat conduction model based on Green's functions agreed well with the experimental results over longer exposure times, and with reduced error when compared with the semi-infinite model. This suggests that modeling the problem on a finite-length scale will produce more accurate or more conservative temperature and heat flux results over extended periods of exposure in high heat load applications. - Highlights: ► Estimation of heat flux and temperature distribution in a body exposed to simulated fire. ► One-dimensional, finite-length scale, transient heat conduction model using a Green's function approach was developed. ► Comparison of

  7. New training simulators of state-of-the-art coal fired power plants at KRAFTWERKSSCHULE E.V.; Neue Schulungssimulatoren moderner Kohlekraftwerke bei der KRAFTWERKSSCHULE E.V.

    Energy Technology Data Exchange (ETDEWEB)

    Kroeck, Martin; Fehse, Klaus; Nacke, Heinrich [Kraftwerksschule e.V., Essen (Germany)

    2008-07-01

    For more than 20 years, KRAFTWERKSSCHULE E.V. (KWS - PowerTech Training Center) operates training simulators for fossil-fired power plants at its Essen headquarters. In the course of the construction of the new 800 MW and 1100 MW high-efficiency power plants with hypercritical steam generators, a growing demand for - even multilingual - training of operator personnel from such plants at simulators is arising. Thus, new training simulators are being erected. (orig.)

  8. Spectral mixture analysis to assess post-fire vegetation regeneration using Landsat Thematic Mapper imagery: Accounting for soil brightness variation

    Science.gov (United States)

    Veraverbeke, S.; Somers, B.; Gitas, I.; Katagis, T.; Polychronaki, A.; Goossens, R.

    2012-02-01

    Post-fire vegetation cover is a crucial parameter in rangeland management. This study aims to assess the post-fire vegetation recovery 3 years after the large 2007 Peloponnese (Greece) wildfires. Post-fire recovery landscapes typically are mixed vegetation-substrate environments which makes spectral mixture analysis (SMA) a very effective tool to derive fractional vegetation cover maps. Using a combination of field and simulation techniques this study aimed to account for the impact of background brightness variability on SMA model performance. The field data consisted out of a spectral library of in situ measured reflectance signals of vegetation and substrate and 78 line transect plots. In addition, a Landsat Thematic Mapper (TM) scene was employed in the study. A simple SMA, in which each constituting terrain feature is represented by its mean spectral signature, a multiple endmember SMA (MESMA) and a segmented SMA, which accounts for soil brightness variations by forcing the substrate endmember choice based on ancillary data (lithological map), were applied. In the study area two main spectrally different lithological units were present: relatively bright limestone and relatively dark flysch (sand-siltstone). Although the simple SMA model resulted in reasonable regression fits for the flysch and limestones subsets separately (coefficient of determination R2 of respectively 0.67 and 0.72 between field and TM data), the performance of the regression model on the pooled dataset was considerably weaker ( R2 = 0.65). Moreover, the regression lines significantly diverged among the different subsets leading to systematic over-or underestimations of the vegetative fraction depending on the substrate type. MESMA did not solve the endmember variability issue. The MESMA model did not manage to select the proper substrate spectrum on a reliable basis due to the lack of shape differences between the flysch and limestone spectra,. The segmented SMA model which accounts for

  9. Climate Change Effects on Multiple Disturbance Interactions: Wildland Fire, Mountain Pine Beetles, and Blister Rust Simulations on a Yellowstone National Park Landscape

    Science.gov (United States)

    Keane, R. E.; Loehman, R.; Smithwick, E. A.

    2011-12-01

    Complex interactions between disturbance, climate, and vegetation will dramatically alter spatial patterns and ecosystem processes in the future, but the interactions between multiple disturbances may ultimately determine vegetation response and landscape dynamics. The frequency and extent of wildland fire, mountain pine beetles, and blister rust are predicted to increase with global warming, but the interactions and reciprocal feedbacks between these three disturbances could also alter landscape trajectories. We used the mechanistic, spatially explicit, landscape FireBGCv2 model parameterized for Yellowstone National Park to determine the extent to which climate altered ecosystem carbon storage, landscape composition and structure, and interacting disturbance regimes that include wildland fire, mountain pine beetles, and white pine blister rust for lodgepole and whitebark pine forests. Under two simulated future climate scenarios (B2 and A2) and three disturbance scenarios (fire only, fire and beetles/rust, beetles/rust only), it appears fire and bark beetle disturbance events interacted to moderate burn area and decrease insect/disease mortality. Landscape composition and structure was roughly the same across disturbance scenarios except whitebark pine disappears when rust is present in the simulation. Overall, we conclude that disturbance interactions are important to landscape dynamics under future climates and these interactions may overwhelm the direct effects of climate or single disturbances.

  10. Adiabatic surface temperature as thermal/structural parameter in fire modeling: Thermal analysis for different wall conductivities

    International Nuclear Information System (INIS)

    The new useful concept of “Adiabatic Surface Temperature” or more commonly known as AST, introduced by Wickström et al. in 2007, is investigated in this study. Adiabatic surface temperature can be used for bridging the gap between fire models and temperature models; for example, it offers the opportunity to transfer both thermal information of the gas and the net heat flux to the solid phase model, obtained by CFD analysis. In this study two numerical analyses are carried out in order to evaluate the effect of wall thermal conductivity and of convective heat transfer coefficient on the adiabatic surface temperature as thermal/structural parameter in fire modeling. First one CFD analysis simulating a fire scenario, “conjugate heat transfer”, with a square beam exposed to hot surface, is carried out to calculate AST, convective heat transfer coefficient and temperature field in the beam. In the second one, a conductive analysis is carried out on “standalone beam” imposing a third type boundary condition on its boundaries assuming the AST, evaluated in the conjugate analysis, as external temperature. Different convective heat transfer coefficients are imposed on the beam walls; the beam is of concrete or steel. Results are presented in terms of net heat flux on beam surfaces, convective heat transfer coefficients and temperature profiles on the beam walls, temperature fields for the two, CFD and conductive, analyses and the relative temperature and net heat flux percent errors. Results underline that convective heat transfer coefficient profiles and adiabatic surface temperatures on the bottom and lateral beam walls are independent of the wall thermal conductivity value, whereas the net heat flux values increase as wall thermal conductivity increases, fixed the emissivity. - Highlights: •The new useful concept of “adiabatic surface temperature” (AST) is investigated. •The effect of wall thermal conductivity and of convective heat transfer

  11. Integrating software architectures for distributed simulations and simulation analysis communities.

    Energy Technology Data Exchange (ETDEWEB)

    Goldsby, Michael E.; Fellig, Daniel; Linebarger, John Michael; Moore, Patrick Curtis; Sa, Timothy J.; Hawley, Marilyn F.

    2005-10-01

    The one-year Software Architecture LDRD (No.79819) was a cross-site effort between Sandia California and Sandia New Mexico. The purpose of this research was to further develop and demonstrate integrating software architecture frameworks for distributed simulation and distributed collaboration in the homeland security domain. The integrated frameworks were initially developed through the Weapons of Mass Destruction Decision Analysis Center (WMD-DAC), sited at SNL/CA, and the National Infrastructure Simulation & Analysis Center (NISAC), sited at SNL/NM. The primary deliverable was a demonstration of both a federation of distributed simulations and a federation of distributed collaborative simulation analysis communities in the context of the same integrated scenario, which was the release of smallpox in San Diego, California. To our knowledge this was the first time such a combination of federations under a single scenario has ever been demonstrated. A secondary deliverable was the creation of the standalone GroupMeld{trademark} collaboration client, which uses the GroupMeld{trademark} synchronous collaboration framework. In addition, a small pilot experiment that used both integrating frameworks allowed a greater range of crisis management options to be performed and evaluated than would have been possible without the use of the frameworks.

  12. High performance single step co-fired solid oxide fuel cells (SOFC): Polarization measurements and analysis

    Science.gov (United States)

    Yoon, Kyung Joong

    At present, one of the major obstacles for the commercialization of solid oxide fuel cell (SOFC) power systems is their high manufacturing costs expressed in terms of SOFC system cost per unit power ($/kW). In this work, anode-supported planar SOFCs were fabricated by a cost-competitive single step co-firing process. The cells were comprised of a porous Ni + yittria-stabilized zirconia (YSZ) anode support, a porous-fine-grained Ni + YSZ anode active layer for some experiments, a dense YSZ electrolyte, a porous-fine-grained Ca-doped LaMnO3 (LCM) + YSZ cathode active layer, and a porous LCM cathode current collector layer. The fabrication process involved tape casting or high shear compaction (HSC) of the anode support followed by screen printing of the remaining component layers. The cells were then co-fired at 1300˜1340°C for 2 hours. The performance of the cell fabricated with the tape casting anode was improved by minimizing various polarization losses through experimental and theoretical modeling approaches, and the maximum power density of 1.5 W/cm 2 was obtained at 800°C with humidified hydrogen (3% H2O) and air. The cells were also tested with various compositions of humidified hydrogen (3˜70% H2O) to simulate the effect of practical fuel utilization on the cell performance. Based on these measurements, an analytical model describing anodic reactions was developed to understand reaction kinetics and rate limiting steps. The cell performance at high fuel utilization was significantly improved by increasing the number of the reaction sites near the anode-electrolyte interface. For anode substrate fabrication, the HSC process offers many advantages such as low fabrication costs, high production throughput, and good control of shrinkage and thickness over the conventional tape casting process. HSC process was successfully employed in single step co-firing process, and SOFCs fabricated with HSC anodes showed adequate performance both at low and high fuel

  13. Visual analysis and steering of flooding simulations.

    Science.gov (United States)

    Ribičić, Hrvoje; Waser, Jürgen; Fuchs, Raphael; Blöschl, Günter; Gröller, Eduard

    2013-06-01

    We present a visualization tool for the real-time analysis of interactively steered ensemble-simulation runs, and apply it to flooding simulations. Simulations are performed on-the-fly, generating large quantities of data. The user wants to make sense of the data as it is created. The tool facilitates understanding of what happens in all scenarios, where important events occur, and how simulation runs are related. We combine different approaches to achieve this goal. To maintain an overview, data are aggregated and embedded into the simulation rendering, showing trends, outliers, and robustness. For a detailed view, we use information-visualization views and interactive visual analysis techniques. A selection mechanism connects the two approaches. Points of interest are selected by clicking on aggregates, supplying data for visual analysis. This allows the user to maintain an overview of the ensemble and perform analysis even as new data are supplied through simulation steering. Unexpected or unwanted developments are detected easily, and the user can focus the exploration on them. The solution was evaluated with two case studies focusing on placing and testing flood defense measures. Both were evaluated by a consortium of flood simulation and defense experts, who found the system to be both intuitive and relevant. PMID:23559514

  14. Analysis of factors influencing deployment of fire suppression resources in Spain using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Costafreda-Aumedes S

    2016-02-01

    Full Text Available In Spain, the established fire control policy states that all fires must be controlled and put out as soon as possible. Though budgets have not restricted operations until recently, we still experience large fires and we often face multiple-fire situations. Furthermore, fire conditions are expected to worsen in the future and budgets are expected to drop. To optimize the deployment of firefighting resources, we must gain insights into the factors affecting how it is conducted. We analyzed the national data base of historical fire records in Spain for patterns of deployment of fire suppression resources for large fires. We used artificial neural networks to model the relationships between the daily fire load, fire duration, fire type, fire size and response time, and the personnel and terrestrial and aerial units deployed for each fire in the period 1998-2008. Most of the models highlighted the positive correlation of burned area and fire duration with the number of resources assigned to each fire and some highlighted the negative influence of daily fire load. We found evidence suggesting that firefighting resources in Spain may already be under duress in their compliance with Spain’s current full suppression policy.

  15. Simulation of a coal-fired power plant using mathematical programming algorithms in order to optimize its efficiency

    International Nuclear Information System (INIS)

    Since most of the world's electric energy production is mainly based on fossil fuels and need for better efficiency of the energy conversion systems is imminent, mathematical programming algorithms were applied for the simulation and optimization of a detailed model of an existing lignite-fired power plant in Kozani, Greece (KARDIA IV). The optimization of its overall thermal efficiency, using as control variables the mass flow rates of the steam turbine extractions and the fuel consumption, was performed with the use of the simulation and optimization software gPROMS. The power plant components' mathematical models were imported in software by the authors and the results showed that further increase to the overall thermal efficiency of the plant can be achieved (a 0.55% absolute increase) through reduction of the HP turbine's and increase of the LP turbine's extractions mass flow rates and the parallel reduction of the fuel consumption by 2.05% which also results to an equivalent reduction of the greenhouse gasses. The setup of the mathematical model and the flexibility of gPROMS, make this software applicable to various power plants. - Highlights: ► Modeling and simulation of the flue gases circuit of a specific plant. ► Designing of modules in gPROMS FO (Foreign Objects). ► Simulation of the complete detailed plant with gPROMS. ► Optimization using a non-linear optimization algorithm of the plant's efficiency.

  16. Cloud effects from boreal forest fire smoke: evidence for ice nucleation from polarization lidar data and cloud model simulations

    International Nuclear Information System (INIS)

    Polarization lidar observations from the interior of Alaska have revealed unusual supercooled altocumulus cloud conditions in the presence of boreal forest fire smoke from local and regional fires. At temperatures of about -15 deg. C, the lidar data show ice nucleation prior to liquid cloud formation (i.e. below water saturation), as well as the occasional glaciation of the liquid layer. Thus the smoke aerosol appears to act as ice nuclei that become activated in updrafts before the liquid cloud forms, as the concentrated aqueous organic solutions are diluted sufficiently to allow them to freeze heterogeneously. This haze particle freezing process is similar to the production of cirrus ice crystals homogeneously at much colder temperatures. To test this hypothesis, cloud microphysical model simulations constrained by the measurements were performed. They indicate that this heterogeneous ice nucleation scenario can be supported by the cloud model. Although ice formation in this manner may generally act in the atmosphere, the boreal smoke particles produce an unusually dramatic effect in the lidar data. We conclude that smoke-induced ice nucleation occurs at moderate supercooled temperatures either through the effects of raised soil/dust particles embedded in the smoke droplets, coated soot aerosol or through the nucleation via certain organic solutions

  17. Simulation and analysis of a main steam line transient with isolation valves closure and subsequent pipe break

    International Nuclear Information System (INIS)

    Simulation and analysis of a real main steam line break transient at the coal fired 300 MW Drmno Thermal Power Plant have been performed by the computer code TEA-01. The methods and procedures used could be applied to a nuclear power plant. 9 refs., 6 figs

  18. Model design to predict forest fire risk in Navarra (Spain) using time series analysis

    OpenAIRE

    Huesca, M; Litago, J.; Palacios-Orueta, A.; Merino de Miguel, Silvia

    2008-01-01

    Understand and predict how forest fire potential changes over time are essential for prioritizing forest management activities and reducing damage. Nowadays we lack the capacity to predict future forest fire trends in response to climate change. The main goal of this research is to build an empirical model to describe, estimate and forecast the forest fires dynamics using the improved Fire Potential Index (FPI) (Huesca et al., 2007) as indicator of fire.

  19. Analysis of forest fires causes and their motivations in northern Algeria: the Delphi method

    OpenAIRE

    Meddour-Sahar O; Meddour R; Leone V; Lovreglio R; Derridj A

    2013-01-01

    Forest fires in Algeria are mostly human-caused and result from local social behavior, whether voluntary (arson) or involuntary (negligence). Understanding the reasons why fires start is, therefore, a crucial factor in preventing or reducing their incidence, developing significant prevention efforts and designing specific fire prevention campaigns. The Delphi method is a promising tool for improving knowledge about how fire starts and why, and above all helps reduce the number of fires starte...

  20. FireCalc: An XML-based framework for distributed data analysis

    International Nuclear Information System (INIS)

    Requirements and specifications for Control Data Access and Communication (CODAC) systems in fusion reactors point towards flexible and modular solutions, independent from operating system and computer architecture. These concepts can also be applied to calculation and data analysis systems, where highly standardized solutions must also apply in order to anticipate long time-scales and high technology evolution changes. FireCalc is an analysis tool based on standard Extensible Markup Language (XML) technologies. Actions are described in an XML file, which contains necessary data specifications and the code or references to scripts. This is used by the user to send the analysis code and data to a server, which can be running either locally or remotely. Communications between the user and the server are performed through XML-RPC, an XML based remote procedure call, thus enabling the client and server to be coded in different computer languages. Access to the database, security procedures and calls to the code interpreter are handled through independent modules, which unbinds them from specific solutions. Currently there is an implementation of the FireCalc framework in Java, that uses the Shared Data Access System (SDAS) for accessing the ISTTOK database and the Scilab kernel for the numerical analysis

  1. An operational manpower analysis of the RQ-8 Fire Scout Vertical Take-Off Unmanned Aerial Vehicle (VTUAV)

    OpenAIRE

    Stracker, Matthew C.

    2007-01-01

    In August of 2001 the Secretary of the Navy announced the Navy would expand the work and experimentation in unmanned vehicle systems. After the events of September 11 this was accelerated with the increased urgency to combat terrorism and asymmetric threats. The U.S. Navy is currently undergoing testing and evaluation of the Fire Scout Vertical Take-Off Unmanned Aerial Vehicle (VTUAV) and its integration into the fleet. An in depth analysis of the Fire Scout's manpower requirements is necessa...

  2. Fire testing and analysis of TRUPACT-I Thermal Test Article

    International Nuclear Information System (INIS)

    This report documents the fabrication and thermal test of a full-scale prototype of the revised TRUPACT-I design. The fire test demonstrated that the response of the Test Article to a jet-fueled pool fire, subsequent to the impact and puncture tests, meets the impact, puncture, and thermal performance requirements of the regulations governing transport of radioactive materials. The Test Article was a replica of the front half (closure end) of the revised TRUPACT-I design. To simulate the cumulative effect of the regulatory hypothetical accident sequence, the Test Article included the structural damage found in TRUPACT-I, Unit 0 after regulatory drop and puncture testing. The Test Article was totally engulfed in a pool fire fueled by JP-4 jet fuel for 46 minutes. The maximum temperature reached at the inner door seals was 149/degree/C (300/degree/F) and the maximum temperature at the inner door filters was 171/degree/C (340/degree/F). Both temperatures are within the normal working range for these components. Post-test leak rate measurements of 0.0041 atm-cm3/s (ANSI standard air) between the innermost pair of door seals and 0.0046 atm-cm3/s (ANSI standard air) between the outermost pair of door seals verified that the performance of the silicone seals met the design requirements. Since no detectable leakage was measured to a sensitivity of 1.0E-7 atm-cm3/s for the filter installation seal or quick-connect valve seal post-test, the total leak rate for the containment system was less than the maximum allowable 0.01 atm-cm3/s (ANSI standard air). 10 refs., 52 figs., 5 tabs

  3. One-dimensional simulation of fire injection heights in contrasted meteorological scenarios with PRM and Meso-NH models

    OpenAIRE

    S. Strada; S. R. Freitas; Mari, C.; Longo, K. M.; Paugam, R.

    2013-01-01

    Wild-fires release huge amounts of aerosol and hazardous trace gases in the atmosphere. The residence time and the dispersion of fire pollutants in the atmosphere can range from hours to days and from local to continental scales. These various scenarios highly depend on the injection height of smoke plumes. The altitude at which fire products are injected in the atmosphere is controlled by fire characteristics and meteorological conditions. Injection height however is sti...

  4. Assessing Wildfire Risk in Cultural Heritage Properties Using High Spatial and Temporal Resolution Satellite Imagery and Spatially Explicit Fire Simulations: The Case of Holy Mount Athos, Greece

    Directory of Open Access Journals (Sweden)

    Giorgos Mallinis

    2016-02-01

    Full Text Available Fire management implications and the design of conservation strategies on fire prone landscapes within the UNESCO World Heritage Properties require the application of wildfire risk assessment at landscape level. The objective of this study was to analyze the spatial variation of wildfire risk on Holy Mount Athos in Greece. Mt. Athos includes 20 monasteries and other structures that are threatened by increasing frequency of wildfires. Site-specific fuel models were created by measuring in the field several fuel parameters in representative natural fuel complexes, while the spatial extent of the fuel types was determined using a synergy of high-resolution imagery and high temporal information from medium spatial resolution imagery classified through object-based analysis and a machine learning classifier. The Minimum Travel Time (MTT algorithm, as it is embedded in FlamMap software, was applied in order to evaluate Burn Probability (BP, Conditional Flame Length (CFL, Fire Size (FS, and Source-Sink Ratio (SSR. The results revealed low burn probabilities for the monasteries; however, nine out of the 20 monasteries have high fire potential in terms of fire intensity, which means that if an ignition occurs, an intense fire is expected. The outputs of this study may be used for decision-making for short-term predictions of wildfire risk at an operational level, contributing to fire suppression and management of UNESCO World Heritage Properties.

  5. Process Simulation Analysis of HF Stripping

    OpenAIRE

    Thaer A. Abdulla

    2013-01-01

       HYSYS process simulator is used for the analysis of existing HF stripping column in LAB plant (Arab Detergent Company, Baiji-Iraq). Simulated column performance and profiles curves are constructed. The variables considered are the thermodynamic model option, bottom temperature, feed temperature, and column profiles for the temperature, vapor flow rate, liquid flow rate and composition. The five thermodynamic models options used (Margules, UNIQUAC, van laar, Antoine, and Zudkevitch-Joffee),...

  6. Mechanistic modeling, numerical simulation and validation of slag-layer growth in a coal-fired boiler

    International Nuclear Information System (INIS)

    In a tangentially coal-fired boiler, for locations inside and near the combustor, heat-transfer by radiation is significant, and hence, ash particles arrive in molten state. The aim of the present study is to adopt a mechanistic modeling approach which incorporates energy-conservation principles to address slag-layer growth. In order to determine the outcome of molten ash impaction, a mechanistic bouncing potential model, incorporating the phenomenon of recoiling of molten ash droplets after impaction, is employed. The bouncing potential is a representation of the excess energy possessed by the recoiling splat, and is used to determine the outcome of molten ash impaction – to stick or to bounce. Computational fluid dynamics techniques, incorporating the effect of thermophoresis, are adopted to estimate the arrival rate of ash particles, and the bouncing potential model, as a user-defined function, is incorporated in the simulation package to determine the status of the droplets after impaction. Two coals of Indian origin are simulated for slag-layer growth for a period of 100 min. The simulation results, when compared with field data provided by BHEL-Trichy, indicate that the model qualitatively predicts the growth of slag-layers. It has been further inferred that smaller particles dominate deposit formation and its growth. - Highlights: • The phenomenon of recoiling of a molten ash droplet after impaction was adopted to simulate slag-layer growth. • Bouncing potential model was incorporated in a computational fluid dynamic package. • The simulation results of two Indian coals were compared with field data and it was inferred that the model qualitatively predicts growth profiles. • Smaller particles, and hence the thermophoretic transport mechanism, are found to dominate deposit formation and its growth

  7. Simulation data analysis by virtual reality system

    International Nuclear Information System (INIS)

    We introduce new software for analysis of time-varying simulation data and new approach for contribution of simulation to experiment by virtual reality (VR) technology. In the new software, the objects of time-varying field are visualized in VR space and the particle trajectories in the time-varying electromagnetic field are also traced. In the new approach, both simulation results and experimental device data are simultaneously visualized in VR space. These developments enhance the study of the phenomena in plasma physics and fusion plasmas. (author)

  8. Thermodynamic analysis of pre-drying methods for pre-dried lignite-fired power plant

    International Nuclear Information System (INIS)

    Lignite is considered to be a competitive energy raw material with very high security of supply viewed from a global angle. However, the utilization of raw lignite faces many thorny issues, such as a low plant thermal efficiency, a high investment in construction of the lignite-fired power plant, etc. Lignite pre-drying seems to be an attractive way to tackle these issues. We have performed a thermodynamic analysis of two pre-drying methods (both boiler flue gas drying and steam drying). Results show that both pre-drying methods can improve the plant thermal efficiency. Nevertheless, the boiler flue gas drying improves the plant thermal efficiency only in the case when the temperature of the dryer exhaust is low enough and the dryer thermal efficiency is high enough. The steam pre-drying has a higher potential in plant thermal efficiency improvement. The flow rate of steam extraction for the steam dryer is much lower than the flow rate of flue gas extraction for flue gas dryer, so we consider that the steam pre-drying is more appropriate for the revamp of the conventional lignite-fired power plant. In addition, we have calculated and analyzed main factors. -- Highlights: ► Lignite pre-drying methods were compared in terms of their contribution to the plant thermal efficiency. ► The theoretical model for thermodynamic analysis of pre-dried lignite-fired power plant was established. ► The steam pre-drying has higher potential in plant thermal efficiency improvement than flue gas pre-drying. ► Main factors influencing the plant thermal efficiency were calculated and analyzed.

  9. Fire Perimeters

    Data.gov (United States)

    California Department of Resources — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2003. Some fires...

  10. Fire History

    Data.gov (United States)

    California Department of Resources — The Fire Perimeters data consists of CDF fires 300 acres and greater in size and USFS fires 10 acres and greater throughout California from 1950 to 2002. Some fires...

  11. Analysis of factors influencing fire damage to concrete using nonlinear resonance vibration method

    International Nuclear Information System (INIS)

    In this study, the effects of different mix proportions and fire scenarios (exposure temperatures and post-fire-curing periods) on fire-damaged concrete were analyzed using a nonlinear resonance vibration method based on nonlinear acoustics. The hysteretic nonlinearity parameter was obtained, which can sensitively reflect the damage level of fire-damaged concrete. In addition, a splitting tensile strength test was performed on each fire-damaged specimen to evaluate the residual property. Using the results, a prediction model for estimating the residual strength of fire-damaged concrete was proposed on the basis of the correlation between the hysteretic nonlinearity parameter and the ratio of splitting tensile strength.

  12. Analysis of factors influencing fire damage to concrete using nonlinear resonance vibration method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gang Kyu; Park, Sun Jong; Kwak, Hyo Gyoung [Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, KAIST, Daejeon (Korea, Republic of); Yim, Hong Jae [Dept. of Construction and Disaster Prevention Engineering, Kyungpook National University, Sangju (Korea, Republic of)

    2015-04-15

    In this study, the effects of different mix proportions and fire scenarios (exposure temperatures and post-fire-curing periods) on fire-damaged concrete were analyzed using a nonlinear resonance vibration method based on nonlinear acoustics. The hysteretic nonlinearity parameter was obtained, which can sensitively reflect the damage level of fire-damaged concrete. In addition, a splitting tensile strength test was performed on each fire-damaged specimen to evaluate the residual property. Using the results, a prediction model for estimating the residual strength of fire-damaged concrete was proposed on the basis of the correlation between the hysteretic nonlinearity parameter and the ratio of splitting tensile strength.

  13. Computer aided seismic and fire retrofitting analysis of existing high rise reinforced concrete buildings

    CERN Document Server

    Hussain, Raja Rizwan; Hasan, Saeed

    2016-01-01

    This book details the analysis and design of high rise buildings for gravity and seismic analysis. It provides the knowledge structural engineers need to retrofit existing structures in order to meet safety requirements and better prevent potential damage from such disasters as earthquakes and fires. Coverage includes actual case studies of existing buildings, reviews of current knowledge for damages and their mitigation, protective design technologies, and analytical and computational techniques. This monograph also provides an experimental investigation on the properties of fiber reinforced concrete that consists of natural fibres like coconut coir and also steel fibres that are used for comparison in both Normal Strength Concrete (NSC) and High Strength Concrete (HSC). In addition, the authors examine the use of various repair techniques for damaged high rise buildings. The book will help upcoming structural design engineers learn the computer aided analysis and design of real existing high rise buildings ...

  14. Analysis of the behaviour of biofuel-fired gas turbine power plants

    Directory of Open Access Journals (Sweden)

    Escudero Marcos

    2012-01-01

    Full Text Available The utilisation of biofuels in gas turbines is a promising alternative to fossil fuels for power generation. It would lead to a significant reduction of CO2 emissions using an existing combustion technology, although considerable changes appear to be required and further technological development is necessary. The goal of this work is to conduct energy and exergy analyses of the behaviour of gas turbines fired with biogas, ethanol and synthesis gas (bio-syngas, compared with natural gas. The global energy transformation process (i.e., from biomass to electricity also has been studied. Furthermore, the potential reduction of CO2 emissions attained by the use of biofuels has been determined, after considering the restrictions regarding biomass availability. Two different simulation tools have been used to accomplish this work. The results suggest a high interest in, and the technical viability of, the use of Biomass Integrated Gasification Combined Cycle (BioIGCC systems for large scale power generation.

  15. A CFD analysis of thermal behaviour of transportation cask under fire test conditions

    International Nuclear Information System (INIS)

    Highlights: → Melting and natural convection of lead in cask has been studied using CFD for the first time. → The role of turbulent natural convection on melting was pronounced. → The study establishes the importance of natural convection for accurate thermal design of cask. - Abstract: Thermal design of transportation cask for shipping radioactive waste needs strict compliance with the guidelines of the regulatory bodies. Lead shielding is usually provided in these casks for arresting gamma rays and reducing hazardous emissions to the environment below permissible limits. During transportation, accidental fire may break out and cause melting of lead for a prescribed duration. The present analysis reports, for the first time, a comprehensive CFD analysis of the thermal behaviour of melting of lead under high Rayleigh number convection during the fire test. The study reveals a substantial influence of natural convection on the thermal state and melting behaviour of lead which may have a great bearing on the safety and security of public during transportation of cask.

  16. GEOMETRIC AND MATERIAL NONLINEAR ANALYSIS OF REINFORCED CONCRETE SLABS AT FIRE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ayad A. Abdul -Razzak

    2013-05-01

    Full Text Available In the present study a nonlinear finite element analysis is presented  to predict the fire resistance of reinforced concrete slabs at fire environment. An eight node layered degenerated shell element utilizing Mindlin/Reissner thick plate theory is employed. The proposed model considered cracking, crushing and yielding of concrete and steel at elevated temperatures. The layered approach is used to represent the steel reinforcement and discretize the concrete slab through the thickness. The reinforcement steel is represented as a smeared layer of equivalent thickness with uniaxial strength and rigidity properties.Geometric nonlinear analysis may play an important role in the behavior of reinforced concrete slabs at high temperature. Geometrical nonlinearity in the layered approach is considered in the mathematical model, which is based on the total Lagrangian approach taking into account Von Karman assumptions.Finally two examples for which experimental results are available are analyzed, using the proposed model .The comparison showed good agreement with experimental results. 

  17. Economic analysis of a supercritical coal-fired CHP plant integrated with an absorption carbon capture installation

    International Nuclear Information System (INIS)

    Energy investments in Poland are currently focused on supercritical coal-fired unit technology. It is likely, that in the future, these units are to be integrated with carbon capture and storage (CCS) installations, which enable a significant reduction of greenhouse gas emissions into the atmosphere. A significant share of the energy market in Poland is constituted by coal-fired combined heat and power (CHP) plants. The integration of these units with CCS installation can be economically inefficient. However, the lack of such integration enhances the investment risk due to the possibility of appearing on the market in the near future high prices of emission allowances. The aforementioned factors and additional favorable conditions for the development of cogeneration can cause one to consider investing in large supercritical CHP plants. This paper presents the results of an economic analysis aimed at comparing three cases of CHP plants, one without an integrated CCS installation and two with such installations. The same steam cycle structure for all variants was adopted. The cases of integrated CHP plants differ from each other in the manner in which they recover heat. For the evaluation of the respective solutions, the break-even price of electricity and avoided emission cost were used. - Highlights: • The simulations of operation of CHP plants under changing load have been realized. • For analyzed cases sensitivity analyses of economic indices have been conducted. • Conditions of competitiveness for integration with CCS units have been identified. • Integration can be profitable if prices of allowance will reach high values, exceeding 50 €/MgCO2. • Others important factors are the investment costs and operation and maintenance costs

  18. 309 Building fire protection analysis and justification for deactivation of sprinkler system. Revision 1

    International Nuclear Information System (INIS)

    Provide a 'graded approach' fire evaluation in preparation for turnover to Environmental Restoration Contractor for D and D. Scope includes revising 309 Building book value and evaluating fire hazards, radiological and toxicological releases, and life safety issues

  19. 309 Building fire protection analysis and justification for deactivation of sprinkler system. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Conner, R.P.

    1997-06-25

    Provide a `graded approach` fire evaluation in preparation for turnover to Environmental Restoration Contractor for D&D. Scope includes revising 309 Building book value and evaluating fire hazards, radiological and toxicological releases, and life safety issues.

  20. Development of an Optimizing Control Concept for Fossil-Fired Boilers using a Simulation Model

    DEFF Research Database (Denmark)

    Mortensen, J. H.; Mølbak, T.; Commisso, M.B.;

    1997-01-01

    An optimizing control system for improving the load following capabilities of power plant units has been developed. The system is implemented as a complement producing additive control signals to the existing boiler control system, a concept which has various practical advantages in terms of...... implementation and commissioning. The optimizing control system takes into account the multivariable and nonlinear characteristics of the boiler process as a gain-scheduled LQG-controller is utilized. For the purpose of facilitating the control concept development a dynamic simulation model of the boiler process...... and the existing control system has been developed and validated. The optimizing control system has been developed and tested by extensive use of the simulation model. Simulation results indicate that a reduction of steam temperature deviations of about 75% can be obtained. The advantages of using a...

  1. Comparing modelled fire dynamics with charcoal records for the Holocene

    Science.gov (United States)

    Brücher, Tim; Brovkin, Victor; Kloster, Silvia; Marlon, Jennifer; Power, Mitch

    2014-05-01

    An Earth System model of intermediate complexity, CLIMBER-2, and land surface model JSBACH that includes dynamic vegetation, carbon cycle, and fire regime are used for simulation of natural fire dynamics through the last 8,000 years. To compare the fire model results with the charcoal reconstructions, several output variables of the fire model (burned area, carbon emissions) and several approaches of model output processing are tested. The z-scores out of charcoal dataset have been calculated for the period 8,000 to 200 BP to exclude a period of strong anthropogenic forcing during the last two centuries. The model analysis points mainly to an increasing fire activity during the Holocene for most of the investigated areas, which is in good correspondence to reconstructed fire trends out of charcoal data for most of the tested regions, while for few regions such as Europe the simulated trend and the reconstructed trends are different. The difference between the modeled and reconstructed fire activity could be due to absence of the anthropogenic forcing in the model simulations, but also due to limitations of model assumptions for modeling fire dynamics. For the model trends, the usage of averaging or z-score processing of model output resulted in similar directions of trend. Therefore, the approach of fire model output processing does not effect results of the model-data comparison. Global fire modeling is still in its infancy; improving our representations of fire through validation exercises such as what we present here is thus essential before testing hypotheses about the effects of extreme climate changes on fire behavior and potential feedbacks that result from those changes. Brücher, T., Brovkin, V., Kloster, S., Marlon, J. R., and Power, M. J.: Comparing modelled fire dynamics with charcoal records for the Holocene, Clim. Past Discuss., 9, 6429-6458, doi:10.5194/cpd-9-6429-2013, 2013.

  2. The impact of baryonic physics on the structure of dark matter haloes: the view from the FIRE cosmological simulations

    Science.gov (United States)

    Chan, T. K.; Kereš, D.; Oñorbe, J.; Hopkins, P. F.; Muratov, A. L.; Faucher-Giguère, C.-A.; Quataert, E.

    2015-12-01

    We study the distribution of cold dark matter (CDM) in cosmological simulations from the FIRE (Feedback In Realistic Environments) project, for M* ˜ 104-11 M⊙ galaxies in Mh ˜ 109-12 M⊙ haloes. FIRE incorporates explicit stellar feedback in the multiphase interstellar medium, with energetics from stellar population models. We find that stellar feedback, without `fine-tuned' parameters, greatly alleviates small-scale problems in CDM. Feedback causes bursts of star formation and outflows, altering the DM distribution. As a result, the inner slope of the DM halo profile (α) shows a strong mass dependence: profiles are shallow at Mh ˜ 1010-1011 M⊙ and steepen at higher/lower masses. The resulting core sizes and slopes are consistent with observations. This is broadly consistent with previous work using simpler feedback schemes, but we find steeper mass dependence of α, and relatively late growth of cores. Because the star formation efficiency M*/Mh is strongly halo mass dependent, a rapid change in α occurs around Mh ˜ 1010 M⊙ (M* ˜ 106-107 M⊙), as sufficient feedback energy becomes available to perturb the DM. Large cores are not established during the period of rapid growth of haloes because of ongoing DM mass accumulation. Instead, cores require several bursts of star formation after the rapid build-up has completed. Stellar feedback dramatically reduces circular velocities in the inner kpc of massive dwarfs; this could be sufficient to explain the `Too Big To Fail' problem without invoking non-standard DM. Finally, feedback and baryonic contraction in Milky Way-mass haloes produce DM profiles slightly shallower than the Navarro-Frenk-White profile, consistent with the normalization of the observed Tully-Fisher relation.

  3. Greenhouse gas emission measurement and economic analysis of Iran natural gas fired power plants

    International Nuclear Information System (INIS)

    This study attempts to examine the natural gas fired power plants in Iran. The required data from natural gas fired power plants were gathered during 2008. The characteristics of thirty two gas turbine power plants and twenty steam power plants have been measured. Their emission factor values were then compared with the standards of Energy Protection Agency, Euro Union and World Bank. Emission factors of gas turbine and steam power plants show that gas turbine power plants have a better performance than steam power plants. For economic analysis, fuel consumption and environmental damages caused by the emitted pollutants are considered as cost functions; and electricity sales revenue are taken as benefit functions. All of these functions have been obtained according to the capacity factor. Total revenue functions show that gas turbine and steam power plants are economically efficient at 98.15% and 90.89% of capacity factor, respectively; this indicates that long operating years of power plants leads to reduction of optimum capacity factor. The stated method could be implemented to assess the economic status of a country’s power plants where as efficient capacity factor close to one means that power plant works in much better condition. - Highlights: • CO2 and NOx emissions of Iran natural gas fired power plants have been studied. • CO2 and NOx emission factors are compared with EPA, EU and World Bank standards. • Costs and benefit as economic functions are obtained according to capacity factor. • Maximum economic profit is obtained for gas turbine and steam power plants. • Investment in CO2 reduction is recommended instead of investment in NOx reduction

  4. Performance analysis of US coal-fired power plants by measuring three DEA efficiencies

    International Nuclear Information System (INIS)

    Data Envelopment Analysis (DEA) has been widely used for performance evaluation of many organizations in private and public sectors. This study proposes a new DEA approach to evaluate the operational, environmental and both-unified performance of coal-fired power plants that are currently operating under the US Clean Air Act (CAA). The economic activities of power plants examined by this study are characterized by four inputs, a desirable (good) output and three undesirable (bad) outputs. This study uses Range-Adjusted Measure (RAM) because it can easily incorporate both desirable and undesirable outputs in the unified analytical structure. The output unification proposed in this study has been never investigated in the previous DEA studies even though such a unified measure is essential in guiding policy makers and corporate leaders. Using the proposed DEA approach, this study finds three important policy implications. First, the CAA has been increasingly effective on their environmental protection. The increased environmental performance leads to the enhancement of the unified efficiency. Second, the market liberalization/deregulation was an important business trend in the electric power industry. Such a business trend was legally prepared by US Energy Policy Act (EPAct). According to the level of the market liberalization, the United States is classified into regulated and deregulated states. This study finds that the operational and unified performance of coal-fired power plants in the regulated states outperforms those of the deregulated states because the investment on coal-fired power plants in the regulated states can be utilized as a financial tool under the rate-of-return criterion of regulation. The power plants in the deregulated states do not have such a regulation premium. Finally, plant managers need to balance between their environmental performance and operational efficiency.

  5. Simulation on an optimal combustion control strategy for 3-D temperature distributions in tangentially pc-fired utility boiler furnaces

    Institute of Scientific and Technical Information of China (English)

    WANG Xi-fen; ZHOU Huai-chun

    2005-01-01

    The control of 3-D temperature distribution in a utility boiler furnace is essential for the safe, economic and clean operation of pcfired furnace with multi-burner system. The development of the visualization of 3-D temperature distributions in pc-fired furnaces makes it possible for a new combustion control strategy directly with the fumacs temperature as its goal to improve the control quality for the combustion processes. Studied in this paper is such a new strategy that the whole furnace is divided into several parts in the vertical direction, and the average temperature and its bias from the center in every cross section can be extracted from the visualization results of the 3-D temperature distributions. In the simulation stage, a computational fluid dynamics (CFD) code served to calculate the 3-D temperature distributions in a furnace, then a linear model was set up to relate the features of the temperature distributions with the input of the combustion processes, such as the flow rates of fuel and air fed into the furnaces through all the burners. The adaptive genetic algorithm was adopted to find the optimal combination of the whole input parameters which ensure to form an optimal 3-D temperature field in the furnace desired for the operation of boiler. Simulation results showed that the strategy could soon find the factors making the temperature distribution apart from the optimal state and give correct adjusting suggestions.

  6. Analysis of Original Causes of Reed Fires in Zhalong Nature Wetland Reserve in Heilongjiang Province

    Institute of Scientific and Technical Information of China (English)

    WANG Mingyu; SHU Lifu; TIAN Xiaorui; WANG Zhicheng

    2006-01-01

    In recent years, serious reed fires occurred in Zhalong Nature Reserve in Heilongjiang Province in China. From 19th to 28th of March 2005, 12 fires occurred in Zhalong Nature Reserve, and the fires spread to Qiqihaer City, Duerberte Mongolian Autonomous County, Lindian County and Daqing City. The burned area was about 18 666 ha. Meteorological factor was the leading factor of its fire environment in Zhalong Nature Reserve, which came into being for a long time. Long-term drought and shortage of rain made the reed and meadow withered and yellow and thus greatly reduced the water content of withered fallen leaves and humus. Much fuel was accumulated and became dry, thus forming the fire environment. Fires in Zhalong Nature Reserve were mainly strong surface fires accompanied by the spread of underground fire. It was extremely easy for reed to burn and spread very quickly. Once a fire broke out, it could spread rapidly to a scene of large fire area, and sometimes it could burn for a long time. Due to lack of correct understanding of the wetland fire and inconvenient wetland traffic, it was unable to find and put out wetland fire in time to save life and property early.

  7. Improved Modelling and Assessment of the Performance of Firefighting Means in the Frame of a Fire PSA

    OpenAIRE

    Martina Kloos; Joerg Peschke

    2015-01-01

    An integrated deterministic and probabilistic safety analysis (IDPSA) was carried out to assess the performances of the firefighting means to be applied in a nuclear power plant. The tools used in the analysis are the code FDS (Fire Dynamics Simulator) for fire simulation and the tool MCDET (Monte Carlo Dynamic Event Tree) for handling epistemic and aleatory uncertainties. The combination of both tools allowed for an improved modelling of a fire interacting with firefighting means while epist...

  8. 火灾情景下的人员可靠性分析%Human Reliability Analysis Under Fire Condition

    Institute of Scientific and Technical Information of China (English)

    何建东; 卓钰铖; 何劼

    2013-01-01

    国内外各核电厂火灾概率安全评价(PSA)表明,人员操作对火灾情景下的电厂风险有重要影响,因此,有必要采用系统的人员可靠性分析(HRA)方法来评价火灾情景下的人员失误概率.本文阐述了HCR/ORE和CBDTM模型的基本理论和在火灾情景下的特殊考虑.将HCR/ORE和CBDTM方法与THERP方法相结合应用于火灾情景下的人员可靠性分析,并进行了实例分析.为建立更符合工程实际的火灾PSA模型奠定了基础.%It is identified in the fire probabilistic safety assessment (PSA) of nuclear power plants that human action has important effect on the risk of plant under fire condition. So it's necessary to assess human error probability under fire condition by the systemic methodology. The HCR/ORE and CBDTM models and specific considerations under fire condition were described in this paper. The combination of HCR/ORE, CBDTM and THERP was applied to human reliability analysis (HRA) under fire condition with an example given for demonstration. The basement of setting up the more practical fire PSA models for engineering is established.

  9. Finite Element Analysis of Fire Truck Chassis for Steel and Carbon Fiber Materials

    Directory of Open Access Journals (Sweden)

    Salvi Gauri Sanjay

    2014-07-01

    Full Text Available Chassis is the foremost component of an automobile that acts as the frame to support the vehicle body. Hence the frame ought to be very rigid and robust enough to resist shocks vibrations and stresses acting on a moving vehicle. Steel in its numerous forms is commonly used material for producing chassis and overtime alumimium has acquired its use. However, in this study traditional materials are replaced with ultra light weight carbon fiber materials. High strength and low weight of carbon fibers makes it ideal for manufacturing automotive chassis. This paper depicts the modal and static structural analysis of TATA 407 fire truck chassis frame for steel as well as carbon fibers. From the analyzed results, stress, strain and total deformation values were compared for both the materials. Since it is easy to analyze structural systems by finite element method, the chassis is modified using PRO-E and the Finite Element Analysis is performed on ANSYS workbench.

  10. Economic analysis of atmospheric mercury emission control for coal-fired power plants in China.

    Science.gov (United States)

    Ancora, Maria Pia; Zhang, Lei; Wang, Shuxiao; Schreifels, Jeremy; Hao, Jiming

    2015-07-01

    Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF+WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments. PMID:26141885

  11. New divisional fire strategy of RoboCup rescue simulation%新的RoboCup救援仿真分区消防策略

    Institute of Scientific and Technical Information of China (English)

    吴云标; 杨宜民

    2011-01-01

    In the fire strategy of RoboCup rescue simulation, controlling the spread of fire plays an important role in rescue effect. Most teams use single-objective selection method based on various indicators of the single building. It is difficult for this method to control the fire effectively when more buildings are in fire or the fire spreads quickly. This paper proposed a new partitioning method based on density cluster. In this method, all the buildings were clustered and seperated into different regions according to the fire spread speed, the target region and buildings extinguishing the fire were selected by the weight considering both the fire spread speed and the building attribute, thus the fire could be controlled even completely extinguished. Finally, the validity of this method has been confirmed through simulation test and competition.%在RoboCup救援仿真的消防策略中,火势蔓延的控制对救援的效果有着重要的作用.大多数队伍采用基于单个建筑的各种指标的单目标选择法,该方法在着火建筑较多或者火势蔓延快时难以对火势进行有效控制.提出一种新的基于密度聚类的分区方法,根据火势蔓延速度将所有建筑进行聚类分析形成建筑簇并分开成为不同的区域,然后综合建筑的属性作为权值选择目标区域和灭火建筑,从而有效地控制火灾的蔓延甚至将火灾完全扑灭.最后通过仿真实验和比赛验证了该方法的有效性.

  12. Failure analysis of austenitic stainless steel tubes in a gas fired steam heater

    International Nuclear Information System (INIS)

    Highlights: ► 304H stainless steel is more susceptible to caustic SCC compared to SA335 alloy steel. ► Caustic attacks the protective layer of stainless steel superheater tubes. ► Sigma phase formation at the weld zone causes crack initiation in fired heater tubes. -- Abstract: Carryover of caustic soda (NaOH) in the steam path caused catastrophic failure of superheater 304H stainless steel tubes in a gas fired heater and led to an unexpected shutdown after just 5 months of continuous service following the start of production. The cause of the failure was studied, with a focus on the effect of caustic embrittlement on stress corrosion cracking (SCC). The cracks were examined at the seam weld, heat affected zone (HAZ), and U-bend areas. Hardness was measured for the base metal, HAZ, and weld metal, and microstructures were examined using optical microscopy and scanning electron microscopy (SEM). Crack initiation is attributed to gouging on the precipitated carbide at the HAZ and also the formation of sigma phase in the weld metal, as shown by energy dispersive X-ray (EDX) analysis. In addition, cracking was propagated by caustic embrittlement because of residual stresses and hammering. Finally, the characteristic feature of fracture was illustrated by SEM fractography, and consists mostly of intergranular SCC and some quasi-cleavage transgranular.

  13. Ash fouling monitoring and key variables analysis for coal fired power plant boiler

    Directory of Open Access Journals (Sweden)

    Shi Yuanhao

    2015-01-01

    Full Text Available Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process, artificial neural networks (ANN are used to optimize the boiler soot-blowing model and mean impact values method is utilized to determine a set of key variables. The validity of the models has been illustrated in a real case-study boiler, a 300MW Chinese power station. The results on same real plant data show that both models have good prediction accuracy, while the ANN model II has less input parameters. This work will be the basis of a future development in order to control and optimize the soot-blowing of the coal-fired power plant utility boilers.

  14. Dynamic and Coupled Simulation of the 700 °C Coal-Fired Power Plant

    OpenAIRE

    2014-01-01

    Im Rahmen dieser Dissertation werden für eine steinkohlegefeuertes Dampfkraftwerk der nächsten Generation mit 705C Frischdampftemperatur und 365 bar Druck sowohl dynamische, als auch detailliert gekoppelte Simulationen durchgeführt. Als Software für die dynamische Simulation wird APROS herangezogen. Das erzeugte Gesamtmodell beinhaltet neben dem Dampferzeuger, der Turbine, dem Kondensator und den Vorwärmgruppen auch ein Mühlenmodell sowie die nötigen Regelungen für Temperatur, ...

  15. All fired up

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Members of the Directorate and their support staff took part in a fire-fighting course organised by the CERN Fire Brigade just before the end-of-year break.  The Bulletin takes a look at the fire-fighting training on offer at CERN.   At CERN the risk of fire can never be under-estimated. In order to train personnel in the use of fire extinguishers, CERN's fire training centre in Prévessin acquired a fire-simulation platform in 2012. On the morning of 17 December 2012, ten members of the CERN directorate and their support staff tried out the platform, following in the footsteps of 400 other members of the CERN community who had already attended the course. The participants were welcomed to the training centre by Gilles Colin, a fire-fighter and instructor, who gave them a 30-minute introduction to general safety and the different types of fire and fire extinguishers, followed by an hour of practical instruction in the simulation facility. There they were able to pract...

  16. Analysis of Palo Verde Nuclear Generating Station unit auxiliary transformer fire

    International Nuclear Information System (INIS)

    On July 6, 1988, the Unit 1 Unit Auxiliary Transformer (UAT) catastrophically failed resulting in a major oil fire. A secondary fire, due to re-energization of a non-class 1E 13.8 KV bus, damaged turbine building switchgear and bus components. The estimated cost of direct damage is approximately $3,400,000. The initiating event leading to the UAT failure was most likely a phase to ground fault in a non-class 1E 13.8 KV bus. The initial fault condition resulted in arcing which propagated into a three phase to ground fault which lead to winding failure and rupture of the UAT. The transformer oil fire was controlled and extinguished by passive and active fire protection features and the plant fire department. The switchgear fire was extinguished by the plant fire department utilizing a CO2 hose reel system. 1 fig

  17. Numerical-simulation research on building-facade geometry and its effect on fire propagation in wooden facades

    OpenAIRE

    Lacasta Palacio, Ana María; Giraldo, Pilar; Avellaneda Diaz-Grande, Jaime; Burgos Leiva, Camila

    2014-01-01

    Fire protection is a very important requirement in the facade of a building. When there is a fire in a building, the facade can be one of the quickest spreading pathways, regardless of the material of which it is constructed. Therefore, in terms of safety, the study of mechanisms controlling the spread of fire through the facade is an issue that needs to be addressed, especially when it involves combustible material claddings such as wood. In several European countries the building regulation...

  18. Analysis of wood firing in stoves by the oxygen consumption method and the carbon dioxide generation method

    International Nuclear Information System (INIS)

    In this paper, we describe the application of two experimental methods on the determination of the heat release rate during the combustion of wood in stoves. The experimental methods are the oxygen consumption method and the carbon dioxide generation method and are adopted from the field of fire safety science. After outlining the basic ideas, we show the necessary equations and analyze the results from an actual experiment. We conclude that both methods appear to be very useful in this application. - Highlights: ► Wood firing in stoves for heating of houses. ► Analysis of heat release rate by two methods coming from fire safety science. ► Oxygen consumption method and carbon dioxide generation method. ► Analysis of experimental data shows that the methods work very well

  19. Fuel type characterization and potential fire behavior estimation in Sardinia and Corsica islands

    Science.gov (United States)

    Bacciu, V.; Pellizzaro, G.; Santoni, P.; Arca, B.; Ventura, A.; Salis, M.; Barboni, T.; Leroy, V.; Cancellieri, D.; Leoni, E.; Ferrat, L.; Perez, Y.; Duce, P.; Spano, D.

    2012-04-01

    BEHAVE fire behavior prediction system (Andrews, 1989) and experimental fuel data. Fire behavior was simulated by setting different weather scenarios representing the most frequent summer meteorological conditions. The simulation outputs (fireline intensity, rate of spread, flame length) were then analyzed for clustering the different fuel types in relation to their potential fire behavior. The results of this analysis can be used to produce fire behavior fuel maps that are important tools in evaluating fire hazard and risk for land management planning, locating and rating fuel treatments, and aiding in environmental assessments and fire danger programs modeling. This work is supported by FUME Project FP7-ENV-2009-1, Grant Agreement Number 243888 and Proterina-C Project, EU Italia-Francia Marittimo 2007-2013 Programme.

  20. How wild is your model fire? Constraining WRF-Chem wildfire smoke simulations with satellite observations

    Science.gov (United States)

    Fischer, E. V.; Ford, B.; Lassman, W.; Pierce, J. R.; Pfister, G.; Volckens, J.; Magzamen, S.; Gan, R.

    2015-12-01

    Exposure to high concentrations of particulate matter (PM) present during acute pollution events is associated with adverse health effects. While many anthropogenic pollution sources are regulated in the United States, emissions from wildfires are difficult to characterize and control. With wildfire frequency and intensity in the western U.S. projected to increase, it is important to more precisely determine the effect that wildfire emissions have on human health, and whether improved forecasts of these air pollution events can mitigate the health risks associated with wildfires. One of the challenges associated with determining health risks associated with wildfire emissions is that the low spatial resolution of surface monitors means that surface measurements may not be representative of a population's exposure, due to steep concentration gradients. To obtain better estimates of ambient exposure levels for health studies, a chemical transport model (CTM) can be used to simulate the evolution of a wildfire plume as it travels over populated regions downwind. Improving the performance of a CTM would allow the development of a new forecasting framework that could better help decision makers estimate and potentially mitigate future health impacts. We use the Weather Research and Forecasting model with online chemistry (WRF-Chem) to simulate wildfire plume evolution. By varying the model resolution, meteorology reanalysis initial conditions, and biomass burning inventories, we are able to explore the sensitivity of model simulations to these various parameters. Satellite observations are used first to evaluate model skill, and then to constrain the model results. These data are then used to estimate population-level exposure, with the aim of better characterizing the effects that wildfire emissions have on human health.

  1. Fire behavior potential in central Saskatchewan under predicted climate change : summary document

    International Nuclear Information System (INIS)

    This study assesses fire danger and fire behaviour potential in central Saskatchewan using simulated climate scenarios produced by the Canadian Regional Climate Model (CRCM), including scenario analysis of base, double and triple level carbon dioxide in the atmosphere and uses available forest fuels to develop an absolute measure of fire behaviour. For each of these climate scenarios, the CRCM-generated weather was used as input variables into the Canadian Forest Fire Behavior Prediction (FBP) System. Fire behavior potential was quantified using head fire intensity, a measure of the fire's energy output because it can be related to fire behavior characteristics, suppression effectiveness, and fire effects. The report discusses the implications of fire behavior potential changes for fire and forest management. Preliminary results suggest a large increase in area burned in the study area by the end of the twenty-first century. Some of the possible fire management activities for long-term prediction include: pre-positioning of resources, preparedness planning, prioritization of fire and forest management activities and fire threat evaluation. 16 refs., 1 tab, 7 figs

  2. Fire risk in California

    Science.gov (United States)

    Peterson, Seth Howard

    Fire is an integral part of ecosystems in the western United States. Decades of fire suppression have led to (unnaturally) large accumulations of fuel in some forest communities, such as the lower elevation forests of the Sierra Nevada. Urban sprawl into fire prone chaparral vegetation in southern California has put human lives at risk and the decreased fire return intervals have put the vegetation community at risk of type conversion. This research examines the factors affecting fire risk in two of the dominant landscapes in the state of California, chaparral and inland coniferous forests. Live fuel moisture (LFM) is important for fire ignition, spread rate, and intensity in chaparral. LFM maps were generated for Los Angeles County by developing and then inverting robust cross-validated regression equations from time series field data and vegetation indices (VIs) and phenological metrics from MODIS data. Fire fuels, including understory fuels which are not visible to remote sensing instruments, were mapped in Yosemite National Park using the random forests decision tree algorithm and climatic, topographic, remotely sensed, and fire history variables. Combining the disparate data sources served to improve classification accuracies. The models were inverted to produce maps of fuel models and fuel amounts, and these showed that fire fuel amounts are highest in the low elevation forests that have been most affected by fire suppression impacting the natural fire regime. Wildland fires in chaparral commonly burn in late summer or fall when LFM is near its annual low, however, the Jesusita Fire burned in early May of 2009, when LFM was still relatively high. The HFire fire spread model was used to simulate the growth of the Jesusita Fire using LFM maps derived from imagery acquired at the time of the fire and imagery acquired in late August to determine how much different the fire would have been if it had occurred later in the year. Simulated fires were 1.5 times larger

  3. Confirmation via Analogue Simulation: A Bayesian Analysis

    CERN Document Server

    Dardashti, Radin; Thebault, Karim P Y; Winsberg, Eric

    2016-01-01

    Analogue simulation is a novel mode of scientific inference found increasingly within modern physics, and yet all but neglected in the philosophical literature. Experiments conducted upon a table-top 'source system' are taken to provide insight into features of an inaccessible 'target system', based upon a syntactic isomorphism between the relevant modelling frameworks. An important example is the use of acoustic 'dumb hole' systems to simulate gravitational black holes. In a recent paper it was argued that there exists circumstances in which confirmation via analogue simulation can obtain; in particular when the robustness of the isomorphism is established via universality arguments. The current paper supports these claims via an analysis in terms of Bayesian confirmation theory.

  4. Stochastic analysis for finance with simulations

    CERN Document Server

    Choe, Geon Ho

    2016-01-01

    This book is an introduction to stochastic analysis and quantitative finance; it includes both theoretical and computational methods. Topics covered are stochastic calculus, option pricing, optimal portfolio investment, and interest rate models. Also included are simulations of stochastic phenomena, numerical solutions of the Black–Scholes–Merton equation, Monte Carlo methods, and time series. Basic measure theory is used as a tool to describe probabilistic phenomena. The level of familiarity with computer programming is kept to a minimum. To make the book accessible to a wider audience, some background mathematical facts are included in the first part of the book and also in the appendices. This work attempts to bridge the gap between mathematics and finance by using diagrams, graphs and simulations in addition to rigorous theoretical exposition. Simulations are not only used as the computational method in quantitative finance, but they can also facilitate an intuitive and deeper understanding of theoret...

  5. Observationally-Motivated Analysis of Simulated Galaxies

    CERN Document Server

    Miranda, M S; Gibson, B K

    2015-01-01

    The spatial and temporal relationships between stellar age, kinematics, and chemistry are a fundamental tool for uncovering the physics driving galaxy formation and evolution. Observationally, these trends are derived using carefully selected samples isolated via the application of appropriate magnitude, colour, and gravity selection functions of individual stars; conversely, the analysis of chemodynamical simulations of galaxies has traditionally been restricted to the age, metallicity, and kinematics of `composite' stellar particles comprised of open cluster-mass simple stellar populations. As we enter the Gaia era, it is crucial that this approach changes, with simulations confronting data in a manner which better mimics the methodology employed by observers. Here, we use the \\textsc{SynCMD} synthetic stellar populations tool to analyse the metallicity distribution function of a Milky Way-like simulated galaxy, employing an apparent magnitude plus gravity selection function similar to that employed by the ...

  6. Wetland fire scar monitoring and analysis using archival Landsat data for the Everglades

    Science.gov (United States)

    Jones, John W.; Hall, Annette E.; Foster, Ann M.; Smith, Thomas J., III

    2013-01-01

    The ability to document the frequency, extent, and severity of fires in wetlands, as well as the dynamics of post-fire wetland land cover, informs fire and wetland science, resource management, and ecosystem protection. Available information on Everglades burn history has been based on field data collection methods that evolved through time and differ by land management unit. Our objectives were to (1) design and test broadly applicable and repeatable metrics of not only fire scar delineation but also post-fire land cover dynamics through exhaustive use of the Landsat satellite data archives, and then (2) explore how those metrics relate to various hydrologic and anthropogenic factors that may influence post-fire land cover dynamics. Visual interpretation of every Landsat scene collected over the study region during the study time frame produced a new, detailed database of burn scars greater than 1.6 ha in size in the Water Conservation Areas and post-fire land cover dynamics for Everglades National Park fires greater than 1.6 ha in area. Median burn areas were compared across several landscape units of the Greater Everglades and found to differ as a function of administrative unit and fire history. Some burned areas transitioned to open water, exhibiting water depths and dynamics that support transition mechanisms proposed in the literature. Classification tree techniques showed that time to green-up and return to pre-burn character were largely explained by fire management practices and hydrology. Broadly applicable as they use data from the global, nearly 30-year-old Landsat archive, these methods for documenting wetland burn extent and post-fire land cover change enable cost-effective collection of new data on wetland fire ecology and independent assessment of fire management practice effectiveness.

  7. The Impact of Baryonic Physics on the Structure of Dark Matter Halos: the View from the FIRE Cosmological Simulations

    Science.gov (United States)

    Keung Chan, Tsang; Keres, Dusan; Oñorbe, Jose; Hopkins, Philip F.; Muratov, Alexander; Faucher-Giguere, Claude-Andre; Quataert, Eliot

    2016-06-01

    We study the distribution of cold dark matter (CDM) in cosmological simulations from the FIRE (Feedback In Realistic Environments) project, which incorporates explicit stellar feedback in the multi-phase ISM, with energetics from stellar population models. We find that stellar feedback, without ``fine-tuned'' parameters, greatly alleviates small-scale problems in CDM. Feedback causes bursts of star formation and outflows, altering the DM distribution. As a result, the inner slope of the DM halo profile (α) shows a strong mass dependence: profiles are shallow at Mh ∼ 1010-1011 M⊙ and steepen at higher/lower masses. The resulting core sizes and slopes are consistent with observations. Because the star formation efficiency, Ms/Mh is strongly halo mass dependent, a rapid change in α occurs around Mh ∼1010M⊙, (Ms∼106-107M⊙) as sufficient feedback energy becomes available to perturb the DM. Large cores are not established during the period of rapid growth of halos because of ongoing DM mass accumulation. Instead, cores require several bursts of star formation after the rapid buildup has completed. Stellar feedback dramatically reduces circular velocities in the inner kpc of massive dwarfs; this could be sufficient to explain the ``Too Big To Fail'' problem without invoking non-standard DM. Finally, feedback and baryonic contraction in Milky Way-mass halos produce DM profiles slightly shallower than the Navarro-Frenk-White profile, consistent with the normalization of the observed Tully-Fisher relation.

  8. Comparing modeled fire dynamics with charcoal records for the Holocene

    Science.gov (United States)

    Bruecher, T.; Brovkin, V.; Kloster, S.; Marlon, J. R.; Power, M. J.

    2013-12-01

    An Earth System model of intermediate complexity, CLIMBER-2, and land surface model JSBACH that includes dynamic vegetation, carbon cycle, and fire regime are used for simulation of natural fire dynamics through the last 8,000 years. To compare the fire model results with the charcoal reconstructions, several output variables of the fire model (burned area, carbon emissions) and several approaches of model output processing are tested. The z-scores out of charcoal dataset have been calculated for the period 8,000 to 200 BP to exclude a period of strong anthropogenic forcing during the last two centuries. The model analysis points mainly to an increasing fire activity during the Holocene for most of the investigated areas, which is in good correspondence to reconstructed fire trends out of charcoal data for most of the tested regions, while for few regions such as Europe the simulated trend and the reconstructed trends are different. The difference between the modeled and reconstructed fire activity could be due to absence of the anthropogenic forcing in the model simulations, but also due to limitations of model assumptions for modeling fire dynamics. For the model trends, the usage of averaging or z-score processing of model output resulted in similar directions of trend. Therefore, the approach of fire model output processing does not effect results of the model-data comparison. Global fire modeling is still in its infancy; improving our representations of fire through validation exercises such as what we present here is thus essential before testing hypotheses about the effects of extreme climate changes on fire behavior and potential feedbacks that result from those changes.

  9. Fire of Life’ analysis of heart rate variability during alpine skiing in Austria

    Directory of Open Access Journals (Sweden)

    Gerhard Litscher

    2010-06-01

    Full Text Available Background: Skiing is a very popular sport in Austria. Nevertheless, there is little information concerning online monitoring of bio-signals during alpine skiing in the mountains. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. Aims: The goal of this study was to demonstrate the new ‘Fire of Life’ heart rate variability analysis for the first time during alpine skiing. Volunteers and Methods: Continuous electrocardiographic monitoring over a period of 12 hours was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems. Two healthy volunteers (female, 20 years, and male, 51 years, both hobby skiers, were monitored simultaneously and continuously during two resting periods before and after active sport and also during alpine skiing. Altogether each participant covered 9,084 meters altitude difference within a time period of 6:14 hours. Total length of the downhill skiing was 45 kilometers. Results: Data acquisition was performed without any technical problems in both subjects. Poincaré plots of sequential R-R intervals (beat to beat variability show two ellipses of different shape and magnitude. During resting periods respiratory sinus arrhythmia and blood pressure effects can be clearly seen in the young female. The same effects, however markedly reduced, are obvious in the older volunteer. Conclusions: The present investigations during alpine skiing highlight the potential value of the ‘Fire of Life’ heart rate variability monitoring even under difficult environmental conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery.

  10. Fire of Life′ analysis of heart rate variability during alpine skiing in Austria

    Directory of Open Access Journals (Sweden)

    Gerhard Litscher

    2010-01-01

    Full Text Available Background : Skiing is a very popular sport in Austria. Nevertheless, there is little information concerning online monitoring of bio-signals during alpine skiing in the mountains. Within the last years innovative scientific monitoring tools for evaluating features of neurocardial fitness have been developed. Aims : The goal of this study was to demonstrate the new ′Fire of Life′ heart rate variability analysis for the first time during alpine skiing. Volunteers and Methods : Continuous electrocardiographic monitoring over a period of 12 hours was performed simultaneously in two healthy volunteers using the same type of equipment (medilog AR12 systems. Two healthy volunteers (female, 20 years, and male, 51 years, both hobby skiers, were monitored simultaneously and continuously during two resting periods before and after active sport and also during alpine skiing. Altogether each participant covered 9,084 meters altitude difference within a time period of 6:14 hours. Total length of the downhill skiing was 45 kilometers. Results : Data acquisition was performed without any technical problems in both subjects. Poincaré plots of sequential R-R intervals (beat to beat variability show two ellipses of different shape and magnitude. During resting periods respiratory sinus arrhythmia and blood pressure effects can be clearly seen in the young female. The same effects, however markedly reduced, are obvious in the older volunteer. Conclusions : The present investigations during alpine skiing highlight the potential value of the ′Fire of Life′ heart rate variability monitoring even under difficult environmental conditions. The innovative kind of analysis helps to show how well the human body reacts to sport, stress and recovery.

  11. National Infrastructure Simulation and Analysis Center Overview

    Energy Technology Data Exchange (ETDEWEB)

    Berscheid, Alan P. [Los Alamos National Laboratory

    2012-07-30

    National Infrastructure Simulation and Analysis Center (NISAC) mission is to: (1) Improve the understanding, preparation, and mitigation of the consequences of infrastructure disruption; (2) Provide a common, comprehensive view of U.S. infrastructure and its response to disruptions - Scale & resolution appropriate to the issues and All threats; and (3) Built an operations-tested DHS capability to respond quickly to urgent infrastructure protection issues.

  12. Methodology for Validating Building Energy Analysis Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Judkoff, R.; Wortman, D.; O' Doherty, B.; Burch, J.

    2008-04-01

    The objective of this report was to develop a validation methodology for building energy analysis simulations, collect high-quality, unambiguous empirical data for validation, and apply the validation methodology to the DOE-2.1, BLAST-2MRT, BLAST-3.0, DEROB-3, DEROB-4, and SUNCAT 2.4 computer programs. This report covers background information, literature survey, validation methodology, comparative studies, analytical verification, empirical validation, comparative evaluation of codes, and conclusions.

  13. Mathematical Analysis and Simulation of Crop Micrometeorology

    OpenAIRE

    Chen, J.

    1984-01-01

    In crop micrometeorology the transfer of radiation, momentum, heat and mass to or from a crop canopy is studied. Simulation models for these processes do exist but are not easy to handle because of their complexity and the long computing time they need. Moreover, up to now such models can only be run on mainframe computers. This study aims at developing a more elegant mathematical analysis that both deepens the understanding of the processes involved, and enables the writing of more efficient...

  14. Performance Analysis Based on Timing Simulation

    DEFF Research Database (Denmark)

    Nielsen, Christian Dalsgaard; Kishinevsky, Michael

    Determining the cycle time and a critical cycle is a fundamental problem in the analysis of concurrent systems. We solve this problemusing timing simulation of an underlying Signal Graph (an extension of Marked Graphs). For a Signal Graph with n vertices and m arcs our algorithm has the polynomial...... time complexity O(b2m), where b is the number of vertices with initially marked in-arcs (typically b≪n). The algorithm has a clear semantic and a low descriptive complexity. We illustrate the use of the algorithm by applying it to performance analysis of asynchronous circuits....

  15. Characterization of active fires in West African savannas by analysis of satellite data: Landsat Thematic Mapper

    International Nuclear Information System (INIS)

    Landsat Thematic Mapper provides valuable information on biomass burning, such as the apparent temperature of a fire and its shape. However, the surface determined by remote sensing does not exactly correspond to the burning area, due to an artificial enlargement of the fire front width. This enlargement of the fire front width. This enlargement may have diverse origins. In particular, it is difficult to estimate the temperature of the areas that are behind the fire front and that have been just burned. Emissions from these areas may be detectable by Landsat channels, thus resulting in the observed enlargement of the fire front. Additional experiments including remote sensing by plane are necessary to allow a more complete understanding of these phenomena. Biomass burning is an important source of atmospheric pollution on a global scale. This study indicates that a fire is a significant source of pollution on a local scale

  16. Fire hazard analysis for the Westinghouse Hanford Company managed low-level mixed waste Trench 31 and 34

    International Nuclear Information System (INIS)

    This analysis is to assess comprehensively the risks from fire within the new lined landfills, provided by W-025 and designated Trench 31 and 34 of Burial Ground 218-W-5; they are located in the 200 West area of the Hanford Site, and are designed to receive low-level mixed waste

  17. Analysis and study on the performance variation of SCR DeNOx catalyst of Coal-Fired Boilers

    International Nuclear Information System (INIS)

    Nitrogen oxides (NOx) are one kind of harmful substances from the burning process of fossil fuel and air at high temperature. NOx emissions cause serious pollution on atmospheric environment. In this paper, coal-fired utility boilers were chosen as the object, NOx formation mechanism and control were studied, and SCR deNOx technology was used to control NOx emissions from coal-fired boilers. Analyzed the relationship between deNOx efficiency and characteristics of SCR DeNOx catalyst. Through analysis, affecting SCR DeNOx catalyst failure factors, change law of catalytic properties and technical measures to extend the service life of the catalyst were gotten. (author)

  18. Time-clustering analysis of forest-fire sequences in southern Italy

    International Nuclear Information System (INIS)

    The investigation of the dynamics of forest-fires is becoming one of the most important scientific challenges in the field of the environmental studies. Time-fractal approaches have been used to characterize the temporal distribution of forest-fire sequences detected in southern Italy. Our findings reveal that the point process modelling the fire sequence can be considered as a fractal process with a high degree of clusterization of the events

  19. Gaston Bachelard's poetics of fire psychoanalysis : the analysis of Bian Zhilin poetry's fire imagery = Jiasidong Bashenla huo de jing shen shi xue li lun : Bian Zhilin xin shi huo yi xiang yun yong tan xi

    OpenAIRE

    Cheung, Hang-hang; 張恆恆

    2015-01-01

    The dissertation is the analysis of famous modern poet Bian Zhilin’s fire imagery in his poems. Dividing Bian Zhilin’s poems into five periods according to the year sequence, it is found that there is high proportion of fire imagery in each period according to the statistical data of the dissertation. As imagery contains poet’s subconsciousness , studying the fire imagery with connect to the history background, helps us reveal the changes of poet’s spirit. The dissertation mainly uses Gas...

  20. Laboratory Investigations of Ni-Al Coatings Exposed to Conditions Simulating Biomass Firing

    DEFF Research Database (Denmark)

    Wu, Duoli; Okoro, Sunday Chukwudi; Dahl, Kristian Vinter;

    2016-01-01

    corrosion attack. Interdiffusion was studied by isothermal heat treatment in static air at 650˚C or 700˚C for up to 3000h. The Ni2Al3 gradually transformed into NiAl and Ni3Al during the interdiffusion process. Porosity developed at the interface between the Ni-Al coating and the Ni layer and expanded with......Fireside corrosion is a key problem when using biomass fuels in power plants. A possible solution is to apply corrosion resistant coatings. The present paper studies the corrosion and interdiffusion behaviour of a Ni-Al diffusion coating on austenitic stainless steel (TP347H). Ni-Al coatings were...... prepared by electrolytic deposition of nickel followed by pack aluminizing performed at 650˚C. A uniform and dense Ni-Al coating with an outer layer of Ni2Al3 and an inner Ni layer was formed. Samples were exposed to 560°C for 168h in an atmosphere simulating biomass combustion. This resulted in localized...

  1. Modeling of compartment fire

    International Nuclear Information System (INIS)

    Fire accident in a containment is a serious threat to nuclear reactors. Fire can cause substantial loss to life and property. The risk posed by fire can also exceed the risk from internal events within a nuclear reactor. Numerous research efforts have been performed to understand and analyze the phenomenon of fire in nuclear reactor and its consequences. Modeling of fire is an important subject in the field of fire safety engineering. Two approaches which are commonly used in fire modeling are zonal modeling and field modeling. The objective of this work is to compare zonal and field modeling approach against a pool fired experiment performed in a well-confined compartment. Numerical simulations were performed against experiments, which were conducted within PRISME program under the framework of OECD. In these experiments, effects of ventilation flow rate on heat release rate in a confined and mechanically ventilated compartment is investigated. Time dependent changes in gas temperature and oxygen mass fraction were measured. The trends obtained by numerical simulation performed using zonal model and field model compares well with experiments. Further validation is needed before this code can be used for fire safety analyses. (author)

  2. Comparative evaluation of the effect of simulated porcelain firing cycle on the mechanical properties and microstructure of base metal ceramic alloys.

    OpenAIRE

    Singla A; Shetty P; Joseph M; Kotian R

    1999-01-01

    A comparison of mechanical properties and microstructure of four metal ceramic alloys in as-cast and heat-treated conditions resulted in significant differences. The alloys that were tested included two nickel-based and two cobalt-based metal ceramic alloys. Mechanical properties tested included strength, percent elongation and hardness. Ten tensile bars were cast for each alloy. Five of the ten bars for each alloy were randomly selected for heat treatment with the simulated porcelain firing ...

  3. Learning to Control Forest Fires

    NARCIS (Netherlands)

    Wiering, M.A.; Dorigo, M.

    1998-01-01

    Forest fires are an important environmental problem. This paper describes a methodology for constructing an intelligent system which aims to support the human expert's decision making in fire control. The idea is based on first implementing a fire spread simulator and on searching for good decision

  4. Biomass integrated gasification combined cycle power generation with supplementary biomass firing: Energy and exergy based performance analysis

    International Nuclear Information System (INIS)

    A thermodynamic analysis of a Biomass Integrated Gasification Combined Cycle (BIGCC) plant has been performed based on energy and exergy balances in a proposed configuration. Combustion of supplementary biomass fuel is considered using the oxygen available in the gas turbine (GT) exhaust. The effects of pressure and temperature ratios of the GT system and the amount of fuel burned in the supplementary firing chamber on the thermal and exergetic efficiencies of the plant have been investigated. The plant efficiencies increase with the increase in both pressure and temperature ratios; however, the latter has a stronger influence than the former. Supplementary firing of biomass increases the plant efficiencies of a BIGCC plant till an optimum level of degree of firing. The other technical issues related to supplementary firing, like ash fusion in the furnace and exhaust heat loss maintaining a minimum pinch point temperature difference are accounted and finally a set of optimum plant operating parameters have been identified. The performance of a 50 MWe plant has been analyzed with the optimum operating parameters to find out equipment rating and biomass feed rates. Exergetic efficiencies of different plant equipments are evaluated to localize the major thermodynamic irreversibilities in the plant. -- Highlights: → A thermodynamic analysis of a Biomass Integrated Gasification Combined Cycle (BIGCC) plant has been performed based on energy and exergy balances across various plant components in a proposed configuration in order to optimize the operating parameters. → The effect of supplementary biomass firing in the BIGCC plant has been analyzed in detail to find out the optimum degree of firing for the best plant performance. → The equipment ratings and fuel feed rates are evaluated and the technical feasibility of the plant configuration has been analyzed. → Exergetic efficiencies of different plant equipments are evaluated to localize the major thermodynamic

  5. Cost analysis of a coal-fired power plant using the NPV method

    Science.gov (United States)

    Kumar, Ravinder; Sharma, Avdhesh Kr.; Tewari, P. C.

    2015-06-01

    The present study investigates the impact of various factors affecting coal-fired power plant economics of 210 MW subcritical unit situated in north India for electricity generation. In this paper, the cost data of various units of thermal power plant in terms of power output capacity have been fitted using power law with the help of the data collected from a literature search. To have a realistic estimate of primary components or equipment, it is necessary to include the latest cost of these components. The cost analysis of the plant was carried out on the basis of total capital investment, operating cost and revenue. The total capital investment includes the total direct plant cost and total indirect plant cost. Total direct plant cost involves the cost of equipment (i.e. boiler, steam turbine, condenser, generator and auxiliary equipment including condensate extraction pump, feed water pump, etc.) and other costs associated with piping, electrical, civil works, direct installation cost, auxiliary services, instrumentation and controls, and site preparation. The total indirect plant cost includes the cost of engineering and set-up. The net present value method was adopted for the present study. The work presented in this paper is an endeavour to study the influence of some of the important parameters on the lifetime costs of a coal-fired power plant. For this purpose, parametric study with and without escalation rates for a period of 35 years plant life was evaluated. The results predicted that plant life, interest rate and the escalation rate were observed to be very sensitive on plant economics in comparison to other factors under study.

  6. Aircraft Fire Protection Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Navy Aircraft Protection Laboratory provides complete test support for all Navy air vehicle fire protection systems. The facility allows for the simulation of a...

  7. Simulation based analysis of laser beam brazing

    Science.gov (United States)

    Dobler, Michael; Wiethop, Philipp; Schmid, Daniel; Schmidt, Michael

    2016-03-01

    Laser beam brazing is a well-established joining technology in car body manufacturing with main applications in the joining of divided tailgates and the joining of roof and side panels. A key advantage of laser brazed joints is the seam's visual quality which satisfies highest requirements. However, the laser beam brazing process is very complex and process dynamics are only partially understood. In order to gain deeper knowledge of the laser beam brazing process, to determine optimal process parameters and to test process variants, a transient three-dimensional simulation model of laser beam brazing is developed. This model takes into account energy input, heat transfer as well as fluid and wetting dynamics that lead to the formation of the brazing seam. A validation of the simulation model is performed by metallographic analysis and thermocouple measurements for different parameter sets of the brazing process. These results show that the multi-physical simulation model not only can be used to gain insight into the laser brazing process but also offers the possibility of process optimization in industrial applications. The model's capabilities in determining optimal process parameters are exemplarily shown for the laser power. Small deviations in the energy input can affect the brazing results significantly. Therefore, the simulation model is used to analyze the effect of the lateral laser beam position on the energy input and the resulting brazing seam.

  8. Analysis of the evaporative towers cooling system of a coal-fired power plant

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2012-01-01

    Full Text Available The paper presents a theoretical analysis of the cooling system of a 110 MW coal-fired power plant located in central Serbia, where eight evaporative towers cool down the plant. An updated research on the evaporative tower cooling system has been carried out to show the theoretical analysis of the tower heat and mass balance, taking into account the sensible and latent heat exchanged during the processes which occur inside these towers. Power plants which are using wet cooling towers for cooling condenser cooling water have higher design temperature of cooling water, thus the designed condensing pressure is higher compared to plants with a once-through cooling system. Daily and seasonal changes further deteriorate energy efficiency of these plants, so it can be concluded that these plants have up to 5% less efficiency compared to systems with once-through cooling. The whole analysis permitted to evaluate the optimal conditions, as far as the operation of the towers is concerned, and to suggest an improvement of the plant. Since plant energy efficiency improvement has become a quite common issue today, the evaluation of the cooling system operation was conducted under the hypothesis of an increase in the plant overall energy efficiency due to low cost improvement in cooling tower system.

  9. Isentropic Analysis of a Simulated Hurricane

    Science.gov (United States)

    Mrowiec, Agnieszka A.; Pauluis, Olivier; Zhang, Fuqing

    2016-01-01

    Hurricanes, like many other atmospheric flows, are associated with turbulent motions over a wide range of scales. Here the authors adapt a new technique based on the isentropic analysis of convective motions to study the thermodynamic structure of the overturning circulation in hurricane simulations. This approach separates the vertical mass transport in terms of the equivalent potential temperature of air parcels. In doing so, one separates the rising air parcels at high entropy from the subsiding air at low entropy. This technique filters out oscillatory motions associated with gravity waves and separates convective overturning from the secondary circulation. This approach is applied here to study the flow of an idealized hurricane simulation with the Weather Research and Forecasting (WRF) Model. The isentropic circulation for a hurricane exhibits similar characteristics to that of moist convection, with a maximum mass transport near the surface associated with a shallow convection and entrainment. There are also important differences. For instance, ascent in the eyewall can be readily identified in the isentropic analysis as an upward mass flux of air with unusually high equivalent potential temperature. The isentropic circulation is further compared here to the Eulerian secondary circulation of the simulated hurricane to show that the mass transport in the isentropic circulation is much larger than the one in secondary circulation. This difference can be directly attributed to the mass transport by convection in the outer rainband and confirms that, even for a strongly organized flow like a hurricane, most of the atmospheric overturning is tied to the smaller scales.

  10. Computer-simulation study on fire behaviour in the ventilated cavity of ventilated façade systems

    OpenAIRE

    Giraldo María P.; Lacasta Ana; Avellaneda Jaume; Burgos Camila

    2013-01-01

    Fire spread through the façades is widely recognized as one of the fastest pathways of fire spreading in the buildings. Fire may spread through the façade in different ways depending on the type of façade system and on the elements and materials from which it is constructed. Ventilated façades are multilayer systems whose main feature is the creation of an air chamber of circulating air between the original building wall and the external cladding. The “chimney effect” in the air c...

  11. Reliability analysis of the fire protection lining in the high speed train tunnel 'Groene Hart'

    NARCIS (Netherlands)

    Krom, A.H.M.; Wit, S. de

    2006-01-01

    Sprayed fire protection linings in bored. high speed train tunnels are a new lield ol application. Questions çere raised on lhe failure probability of the lining during the sen,ice life of the Groene Hart tunnel. The fire protection Iining is reinforced with a wire mcsh fixed to the tunnel lining, A

  12. Probabilistic and deterministic safety analysis of NPP with WWER-1000 of fire

    International Nuclear Information System (INIS)

    The paper presents the methodology for safe shutdown of the reactor in case of fire. The first results obtained for WWER 1000 (B-320) are given. Studies have been conducted at the Balakovo NPP. Information about data bases on fire hazards at the currently operating NPPs is also given in the report

  13. How knowledge influences a MCDM analysis: WOCAT Portuguese experience on prevention of forest fires

    Science.gov (United States)

    Carreiras, M.; Ferreira, A. J. D.; Moreira, J.; Esteves, T. C. J.; Valente, S.; Soares, J.; Coelho, C. O. A.; Schwilch, G.; Bachmann, F.

    2012-04-01

    degradation processes. Affecting large areas every year, they also have serious human, socio-economic and psychological impacts. Under the DESIRE project two Portuguese study sites were selected - Góis e Mação. Both study sites are located in Central Portugal and are frequently affected by forest fires. Nowadays different types of solutions applied at the local level are related with the prevention, combat and mitigation of forest fires. At a higher level of analysis the main solution is related with the diversification of the soil uses, mainly by the mixture of cropland, pastures and forest areas. But the selection of the technique isn't so far an open, participative and effective process, and the interests of land users are not represented most of the time. This paper aims to present WOCAT approach and results to forest fire prevention in Portugal considering stakeholder's perspectives and policy recommendations and it's evolution based on an increased of knowledge.

  14. Sample Analysis at Mars Instrument Simulator

    Science.gov (United States)

    Benna, Mehdi; Nolan, Tom

    2013-01-01

    The Sample Analysis at Mars Instrument Simulator (SAMSIM) is a numerical model dedicated to plan and validate operations of the Sample Analysis at Mars (SAM) instrument on the surface of Mars. The SAM instrument suite, currently operating on the Mars Science Laboratory (MSL), is an analytical laboratory designed to investigate the chemical and isotopic composition of the atmosphere and volatiles extracted from solid samples. SAMSIM was developed using Matlab and Simulink libraries of MathWorks Inc. to provide MSL mission planners with accurate predictions of the instrument electrical, thermal, mechanical, and fluid responses to scripted commands. This tool is a first example of a multi-purpose, full-scale numerical modeling of a flight instrument with the purpose of supplementing or even eliminating entirely the need for a hardware engineer model during instrument development and operation. SAMSIM simulates the complex interactions that occur between the instrument Command and Data Handling unit (C&DH) and all subsystems during the execution of experiment sequences. A typical SAM experiment takes many hours to complete and involves hundreds of components. During the simulation, the electrical, mechanical, thermal, and gas dynamics states of each hardware component are accurately modeled and propagated within the simulation environment at faster than real time. This allows the simulation, in just a few minutes, of experiment sequences that takes many hours to execute on the real instrument. The SAMSIM model is divided into five distinct but interacting modules: software, mechanical, thermal, gas flow, and electrical modules. The software module simulates the instrument C&DH by executing a customized version of the instrument flight software in a Matlab environment. The inputs and outputs to this synthetic C&DH are mapped to virtual sensors and command lines that mimic in their structure and connectivity the layout of the instrument harnesses. This module executes

  15. The assessment of design fire cases on offshore installations using process analysis method

    International Nuclear Information System (INIS)

    The inquiry into the Piper Alpha disaster chaired by Lord Cullen, highlighted the short-comings of a prescriptive approach to safety and in particular, those of fire protection. This paper describes a method of critically analyzing the process sections and areas to determine the worst fire conditions which could occur following a hydrocarbon release. The results of the analyses would be used as the basis for fire protection design on a new platform or for assessing the adequacy of the protection on an existing installation thus allowing designers to adopt the goal setting approach advocated in the Inquiry, ie, designing systems to suit the fire hazards rather than to suit the regulations. It will also enable process engineers to appreciate the scale of fire hazards which might arise from poor design

  16. Mechanical Analysis of an SM 2 Blk IV restrained firing within a concentric canister launcher test unit

    Energy Technology Data Exchange (ETDEWEB)

    Kassner, M C; Kennedy, T C; Puttapitukporn, T; Rosen, R S

    1999-03-01

    The Office of Naval Research (ONR) and PMS512 have undertaken a program to develop a new Vertical Launching System (VLS) for future generation ships, such as the DD-21 Destroyer. The Naval Sea Systems Command Combat Weapons Program (NAVSEA 05K) and Naval Surface Warfare Center Dahlgren Division (NSWCDD) are working jointly with industry and universities to develop one such launcher design, the Concentric Canister Launcher (CCL). The basic CCL design consists of a tube made of two concentric cylinders; one end is open, the other is sealed with a hemispherical end cap. During firing, the missile exhaust gas is turned 180 degrees by the hemispherical end cap and flows through the annular space between inner and outer cylinders. Depending on the missile utilized and the particular service environment of the CCL, maximum temperatures within the cylinder material have been calculated to exceed 2000 F. In an earlier study [1], the authors determined the high temperature mechanical properties of several candidate alloys being considered for fabrication of the CCL. This study [1] found that, of these candidate materials, titanium alloys exhibit higher yield stresses than that of 316L stainless steel at temperatures up to about 1000 F; above 1500 F, the yield stress of 316L stainless steel is comparable to those of the titanium alloys. The 316L stainless steel was found to strain harden (increase its flow stress with increasing strain) at temperatures up to about 1800 F. The ability of the 316L stainless steel to strain harden at high temperatures may provide an added margin of safety for engineering design of the CCL. The objective of the current study was to perform a computer simulation of the structural response of a CCL during a restrained firing, one in which a SM-2 Blk IV missile would fail to exit the canister. A finite element model of the inner cylinder, outer cylinder, end rings (mounting brackets), and lateral restraints in the uptake was constructed. An elastic

  17. Mechanical Analysis of an SM 2 Blk IV restrained firing within a concentric canister launcher test unit; TOPICAL

    International Nuclear Information System (INIS)

    The Office of Naval Research (ONR) and PMS512 have undertaken a program to develop a new Vertical Launching System (VLS) for future generation ships, such as the DD-21 Destroyer. The Naval Sea Systems Command Combat Weapons Program (NAVSEA 05K) and Naval Surface Warfare Center Dahlgren Division (NSWCDD) are working jointly with industry and universities to develop one such launcher design, the Concentric Canister Launcher (CCL). The basic CCL design consists of a tube made of two concentric cylinders; one end is open, the other is sealed with a hemispherical end cap. During firing, the missile exhaust gas is turned 180 degrees by the hemispherical end cap and flows through the annular space between inner and outer cylinders. Depending on the missile utilized and the particular service environment of the CCL, maximum temperatures within the cylinder material have been calculated to exceed 2000 F. In an earlier study[1], the authors determined the high temperature mechanical properties of several candidate alloys being considered for fabrication of the CCL. This study[1] found that, of these candidate materials, titanium alloys exhibit higher yield stresses than that of 316L stainless steel at temperatures up to about 1000 F; above 1500 F, the yield stress of 316L stainless steel is comparable to those of the titanium alloys. The 316L stainless steel was found to strain harden (increase its flow stress with increasing strain) at temperatures up to about 1800 F. The ability of the 316L stainless steel to strain harden at high temperatures may provide an added margin of safety for engineering design of the CCL. The objective of the current study was to perform a computer simulation of the structural response of a CCL during a restrained firing, one in which a SM-2 Blk IV missile would fail to exit the canister. A finite element model of the inner cylinder, outer cylinder, end rings (mounting brackets), and lateral restraints in the uptake was constructed. An elastic

  18. Airborne forest fire research

    Science.gov (United States)

    Mattingly, G. S.

    1974-01-01

    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included.

  19. Space Debris Attitude Simulation - IOTA (In-Orbit Tumbling Analysis)

    Science.gov (United States)

    Kanzler, R.; Schildknecht, T.; Lips, T.; Fritsche, B.; Silha, J.; Krag, H.

    Today, there is little knowledge on the attitude state of decommissioned intact objects in Earth orbit. Observational means have advanced in the past years, but are still limited with respect to an accurate estimate of motion vector orientations and magnitude. Especially for the preparation of Active Debris Removal (ADR) missions as planned by ESA's Clean Space initiative or contingency scenarios for ESA spacecraft like ENVISAT, such knowledge is needed. The In-Orbit Tumbling Analysis tool (IOTA) is a prototype software, currently in development within the framework of ESA's “Debris Attitude Motion Measurements and Modelling” project (ESA Contract No. 40000112447), which is led by the Astronomical Institute of the University of Bern (AIUB). The project goal is to achieve a good understanding of the attitude evolution and the considerable internal and external effects which occur. To characterize the attitude state of selected targets in LEO and GTO, multiple observation methods are combined. Optical observations are carried out by AIUB, Satellite Laser Ranging (SLR) is performed by the Space Research Institute of the Austrian Academy of Sciences (IWF) and radar measurements and signal level determination are provided by the Fraunhofer Institute for High Frequency Physics and Radar Techniques (FHR). Developed by Hyperschall Technologie Göttingen GmbH (HTG), IOTA will be a highly modular software tool to perform short- (days), medium- (months) and long-term (years) propagation of the orbit and attitude motion (six degrees-of-freedom) of spacecraft in Earth orbit. The simulation takes into account all relevant acting forces and torques, including aerodynamic drag, solar radiation pressure, gravitational influences of Earth, Sun and Moon, eddy current damping, impulse and momentum transfer from space debris or micro meteoroid impact, as well as the optional definition of particular spacecraft specific influences like tank sloshing, reaction wheel behaviour

  20. Laser heating: a minimally invasive technique for studying fire-generated heating in building stone

    OpenAIRE

    Ocaña, José Luis; Molpeceres, Carlos; Morcillo, Miguel; Fort, Rafael; Gómez-Heras, Miguel

    2008-01-01

    Due to the irreparable damage it can cause, fire is one of the major risks to buildings. Recent studies on the effects of fire tend to focus on micro-scale analysis, addressing questions such as micro-cracking or mineralogical or chemical changes that are particularly relevant to listed buildings.The fire simulation techniques employed to date (convection heating laboratory furnaces and real flame tests) are subject to a series of limitations including non-repeatability, the lack of combustio...