Critical Review on Photovoltaic Fire Safety in Buildings from Ignition to Smoke Control and Intervention

Fire safety and security system in high-rise buildings has been a significant issue from the last century. However, there are numerous provisions for safety measures from such fires and the magnitude and nature of the problem of this hazard has been unknown. This study identifies the location of high-rise buildings in Tangail pourashava through an extensive survey and then identifies the unique fire safety problems of those buildings and their associated fire risk. As it turns out, most of those buildings are highly vulnerable to fire risk due to lack of major fire fighting equipments and defiance of related laws and regulations. The study then addresses the means to provide fire safety in those buildings from both design and codes perspectives. It elaborates on the need to provide both building and occupant based protection to achieve the best results. It concludes with an overview of the special problems associated with high-rise buildings combined with specific use and occupancy-related requirements, employee training and response.J. Environ. Sci. & Natural Resources, 10(1): 33-40 2017

A wide variety of active fire protection systems are available to fire safety practitioners. In addition to passive fire protection measures, some level of active fire protection is normally required to meet the expected minimum level of fire safety in modern buildings. Active fire protection can also be used to increase the fire safety in order to achieve a more flexible fire safety design and an acceptable level of fire safety in buildings. There are many types of active fire protection systems, but this chapter deals mainly with automatic fire sprinkler systems, since they are often used to facilitate the use of timber as structure, internal linings and external facades in large or complex buildings. Sprinklers are required in some countries for taller timber buildings, as described in Chapter 4.

Purpose The current fire protection measures in buildings do not account for all contemporary fire hazard issues, which has made fire safety a growing concern. Therefore, this paper aims to present a critical review of current fire protection measures and their applicability to address current challenges relating to fire hazards in buildings. Design/methodology/approach To overcome fire hazards in buildings, impact of fire hazards is also reviewed to set the context for fire protection measures. Based on the review, an integrated framework for mitigation of fire hazards is proposed. The proposed framework involves enhancement of fire safety in four key areas: fire protection features in buildings, regulation and enforcement, consumer awareness and technology and resources advancement. Detailed strategies on improving fire safety in buildings in these four key areas are presented, and future research and training needs are identified. Findings Current fire protection measures lead to an unquantified level of fire safety in buildings, provide minimal strategies to mitigate fire hazard and do not account for contemporary fire hazard issues. Implementing key measures that include reliable fire protection systems, proper regulation and enforcement of building code provisions, enhancement of public awareness and proper use of technology and resources is key to mitigating fire hazard in buildings. Major research and training required to improve fire safety in buildings include developing cost-effective fire suppression systems and rational fire design approaches, characterizing new materials and developing performance-based codes. Practical implications The proposed framework encompasses both prevention and management of fire hazard. To demonstrate the applicability of this framework in improving fire safety in buildings, major limitations of current fire protection measures are identified, and detailed strategies are provided to address these limitations using proposed fire safety framework. Social implications Fire represents a severe hazard in both developing and developed countries and poses significant threat to life, structure, property and environment. The proposed framework has social implications as it addresses some of the current challenges relating to fire hazard in buildings and will enhance overall fire safety. Originality/value The novelty of proposed framework lies in encompassing both prevention and management of fire hazard. This is unlike current fire safety improvement strategies, which focus only on improving fire protection features in buildings (i.e. managing impact of fire hazard) using performance-based codes. To demonstrate the applicability of this framework in improving fire safety in buildings, major limitations of current fire protection measures are identified and detailed strategies are provided to address these limitations using proposed fire safety framework. Special emphasis is given to cost-effectiveness of proposed strategies, and research and training needs for further enhancing building fire safety are identified.

Current large-scale wind turbine installations are sited using layouts based on site topology, real estate costs and restrictions, and turbine power output. Existing optimization programs attempt to site multiple turbines based on simple geometric turbine wake models, which typically overestimate individual turbine output. In addition, advanced Computational Fluid Dynamics (CFD) modeling of individual turbine wake fields have revealed complex flow patterns and “wake meandering” which have not been taken into account in current optimization and flow field models. CFD models of entire turbine fields have had limited application because of the enormous compute resources required; limitations of the simplified turbine models used which do not provide high resolution results in the wake field; and the lack of efforts to adapt the results of complex CFD output to analytical models which can be incorporated into wind turbine siting optimization routines. In this paper, we report on our efforts to simulate flow past wind turbines using a new adaptation of the Actuator Line (AL) method for turbine blade modeling. This method creates a geometric representation of each rotating turbine blade. Grid points in the CFD flow field are selected within the outline of the blades and near downstream planes, and the aerodynamic forces are calculated using traditional blade element equations. The forces are distributed using an automated routine which dynamically determines the application area based on the number of applied grid points at each time step. Turbine blades are rotated in time with progressing CFD field calculations. This method distributes blade forces without using a geometric distribution function used in other recent research. Blade forces are then input as body forces into the Navier Stokes equations in the host CFD program. A Smagorisnky LES turbulence model is employed to model turbulent effects. To improve accuracy and reduce computing power requirements, the advanced parallel CFD code, NEK5000, is used in this study. FORTRAN subroutines are written to generate the actuator line and blade geometry, and to calculate the blade lift and drag forces. These subroutines are then linked to the solver source code and compiled. Details of the actuator line setup and calculations, LES turbulence model, CFD flow simulation setup, and results from current turbine runs will be presented. Current results are consistent with published research. A roadmap to ongoing development will also be discussed.

Nowadays the use of photovoltaic (PV) systems in buildings is not only related to the solar energy conversion into electrical one, but these PV modules or panels could also be used with aesthetic features or, even more, as thermal protection systems in building facades. Thanks to the technical development of the photovoltaic industry, PV system can easily be architectonically integrated into building construction elements such as roofs, vertical façade components, both with opaque or transparent surfaces. Furthermore, PV construction facades elements could also be provided by openings like doors or windows. Accident analysis show that the use of PV systems as construction elements could increase the risk of fire in buildings. In fact, international and National data report a growing number of fire caused by PV system applied or integrated in buildings. The Italian National Fire Service, that is the Authority having jurisdiction for fire safety in buildings (in Italy), in 2012 has released a Guideline in order to asses and mitigate the risk of fire when a PV system is put in place on a building as a façade or as a roof. The Guideline addresses not only the reduction of the PV fire ignitions causes and the aspects related to the fire spread due to the combustible parts that constitute PV modules or panels, but also take into account the safety of both the maintenance personnel and the rescue teams. This paper focuses on the fire safety aspects related to the use of fire PV panels and systems in building facades, showing some interesting experimental data related to the fire behaviour of these components and underlining the factors that promote the spread of fire, like the high operating temperature of the PV system itself.

Changes have occurred internationally in regulations for fire safety in buildings, and there has been significant recent progress towards rational design for fire safety in buildings. Possible design objectives for fire safety are listed and the interacting factors that influence fire safety in buildings are discussed. A factor of particular importance is fire growth and development, with recent developments in this area leading to increased recognition of non‐uniform conditions occurring in many enclosures of practical significance in fire safety design. Coroner's records and fire statistics have been used to improve our understanding of the factors that lead to casualties (particularly fatalities) in fires, and these have shown that the structure is rarely a factor.Recent progress in understanding and modelling the behaviour of steel structures in fires is reviewed. Recent testing for modern structural steels has resulted in new data for thermal expansion and stress‐related and creep strain, with new mathematical relationships for strain that can easily be used in computer models. Studies of the response of steel columns and composite beams are reviewed, including studies of the effect of temperature gradients and axial restraint on column performance, the development of a simplified equation for concrete‐filled tubular column behaviour and lateral buckling of beams. A major area of recent research is the behaviour in fire of significant parts of a building structure (rather than individual members), particularly in response to the Cardington eight storey steel‐framed building tests. Several recently published approaches to modelling overall structural behaviour are reviewed in the light of these tests.

Developing technology, changing social structures, and the threat of resource depletion have changed the design of buildings. Therefore, design approaches are developed to increase user comfort and reduce energy consumption by utilizing natural ventilation and lighting. The design of the distribution of outdoor air and light into the spaces through vertical and horizontal gaps reduces the energy demand of the mechanical systems and increases occupant comfort. The atrium is the preferred vertical gap in modern buildings for distributing natural air and light to interior spaces under appropriate conditions. However, in buildings with atrium, there is a risk of fire spreading in the event of a fire due to the uninterrupted gaps between the rooms. It is necessary to ensure the operability of the design by monitoring the measures to be taken in the early stages of design using performance-based fire safety methods. This study develops design strategies for fire analysis in atrium buildings using computational fluid dynamics (CFD) simulation technology. Atrium height, roof type, and slope characteristics are analyzed for the stack effect, which is the main factor in the movement of smoke and flames. As a result of the numerical analyses consisting of flat, unidirectional, and bidirectional sloping roof type, 10, 20, 30-degree roof slope, and one-meter rising atrium roof variables, the effect degrees for smoke dispersal and temperature control are investigated. Fire Dynamic Simulator, which uses CFD capabilities, and Smokeview software, which can visualize the results, were used for the numerical analysis. Correlation analysis was used to determine the effect of variables on temperature. The results showed that flat roofs and designs with increasing height were effective in delaying the spread of smoke and increasing the stack effect in the atrium, while the contribution of roof slope to fire safety was weak.

Achieving optimum design solutions, with regards to fire and fire safety conditions, is an uncompromisable endeavour. As such, considering the destruction that has been occurring if treated lightly, every architectural design must consciously and constantly bear in mind, the goal of avoiding such disaster. Resting on this premise, this paper aimed at identifying major design approaches that need to be adopted to achieve optimum fire safety in buildings, right from the design stage. The paper adopted a narrative literature review approach to identify grounded design considerations related to fire and fire safety. One of the findings was that a design must be carried out with the conscious intention to provide a high level of safety affordances to occupants of buildings and their properties in case of fire outbreaks. Much of the affordances should be related to smoke, which tends to be more dangerous than the fire itself. The paper is highly significant for any architectural design since it seemed to avoid the likely destruction of everything and everyone that a person has possessed or has ever loved.

Fire safety in buildings - overview: fire safety objectives process of fire development conceptual framework for fire safety fire resistance controlling fire spread building construction for fire safety. Fire and heat - overview: fuels combustion fire initiation burning objects t-squared fires pre-flashover design fires heat transfer. Room fires - overview: pre-flashover fires flashover post-flashover fires design fires other factors. Fire severity - overview: fire severity and fire resistance fire severity standard fire equivalent fire severity. Fire resistance - overview: fire resistance assessing fire resistance fire-resistance tests approved fire-resistance ratings fire resistance by calculation fire resistance of assemblies. Design of structures exposed to fire - overview: structural design at normal temperatures structural design in fire conditions material properties in fire design of individual members exposed to fire design of structural assemblies exposed to fire. Steel structures: overview: behaviour of steel structures in fire fire-resistance ratings steel temperatures protection systems mechanical properties of steel at elevated temperature design of steel members exposed to fire design of steel buildings exposed to fire. Concrete structures - overview: behaviour of concrete structures in fire fire-resistance ratings concrete and reinforcing temperatures mechanical properties of concrete at elevated temperatures design of concrete members exposed to fire composite steel-concrete construction exposed to fire. Timber structures - overview: description of timber construction fire-resistance ratings wood temperatures mechanical properties of wood design concepts for heavy timber exposed to fire design of heavy timber members exposed to fire behaviour of timber connections in fire.

This study examines how students perceive fire safety during the architectural education process and the solutions they make for it. The scope of the study consists of the projects designed by the architecture students who took the "Fire Safety in Buildings" course in the Fall Semester of the 2020-2021 and 2021-2022 Academic Years at Ondokuz Mayıs University, Department of Architecture. Within the scope of the study, 91 student projects were discussed in the context of fire safety in line with the principles in the Regulation on the Protection of Buildings from Fire. The study findings showed that the student projects needed to improve regarding the measures taken against fire. According to this research, the measures taken for fire safety in the projects of architecture students are caused by insufficient and incomplete reading. Such deficiencies can be eliminated with minor corrections in most designs if the regulations are examined. For this reason, it has been determined that at the very beginning of the design phase, measures for fire safety -including legislative readings- should be included in the design stage. As a result, the findings from the student projects were discussed, and some general suggestions were made on fire safety.

The pressurized smoke control system in the vestibule is important for fire safety in buildings because it is concerned with egress time of people and the safety of fire fighters. The vestibule pressurization system can prevent smoke from entering the vestibule using differential pressure when fire doors are closed and using the egress velocity when fire doors are open. Air supplying units in the vestibule need to be arranged by taking account of the location of doors and the volume of the vestibule in order to assure the uniform air egress velocity through a fire door when it is open. In this study, computational fluid dynamics (CFD) simulations were conducted for the vestibule where multiple doors are installed and it was found that the reverse flow occurs when the damper position in vestibule is not appropriate.

The criticality of 21 st century advantages in energy saving opportunities has led aerospace companies around the world to once again revisit the Open Fan or more commonly Counter Rotating Open Rotor (CROR) engine technology in the past several years. The phenomenal advancements in computational fluid dynamics (CFD) technology over the past decade led to an expanded role in the test planning of a 2010 joint Boeing/Rolls-Royce CROR wind tunnel test campaign at the RUAG Aviation LWTE (Low Speed Wind Tunnel Emmen) in Emmen, Switzerland. The success of the validation of the CFD results as a test planning tool, as well as comparing the computation results themselves against wind tunnel measurements, will be examined in this paper. A large number of propeller operating conditions were analyzed with the momentum source rotor model in a steady CFD model prior to the test, greatly assisting in the determination of the run matrix. The test results were then used to evaluate the limitation of the steady CFD method, and to further validate the state-of-art unsteady CFD methodology. The CFD off-body results also helped in the post-test understanding of the wind tunnel results. Improvements to the CFD modeling were in turn made as a result of analysis of the tunnel results. While CFD was used for both isolated and full model cases, this paper will present results using the CFD code OVERFLOW2.1 for the isolated CROR configuration alone.

Auxiliary power units (APUs) are gas turbine engines that provide high-pressure air and electrical power to aircraft systems. They provide primary power while the aircraft is parked on the ramp, starting services for the main engines, and backup power while the aircraft is in flight. Many APUs employ inlet systems which include a “pop-up” door that allow for the capture of freestream ram pressure during flight. This results in increased inlet recovery and a corresponding improvement in the performance of the APU. This APU door, when open, is exposed to airflow instability inherent in the aircraft boundary layer in the aft section of the fuselage, where APUs are typically housed. Additionally, the pop-up nature of the inlet door produces a large region of separated airflow off of the back side of the door. Systematic vortex shedding is frequently a major component of this separated region. As new APU doors are made with less rigid material to save weight, a need to better understand the unsteady aerodynamic excitations of the flow field around the door has arisen, as these new doors may be more susceptible to vibration during flight. Recent advances in Computational Fluid Dynamics (CFD) meshing tools and transient modeling have enabled a CFD study to be performed which will investigate this time-dependent phenomenon. As transient CFD analysis is still a relatively new field for commercial CFD codes, a calibration was needed to verify the accuracy of the CFD predictions and to form any calibration correction terms. Honeywell Aerospace owns a Boeing 757 flight test vehicle which is normally used to flight test propulsion engines. However, this aircraft also includes a pop-up APU inlet door that is similar to most other APU inlet door styles. This APU door was instrumented using high response pressure transducers placed on the forward and aft sides of the inlet door as well as upstream of the door to measure upstream instability. The aircraft was flown at a variety of flight conditions and APU operating points and the transient data was recorded. After the completion of the flight test, a CFD model was constructed of the B757 flight test vehicle. Because aerodynamic instability can be generated anywhere on the aircraft, the entire airframe from nose to tail was modeled. The APU inlet door geometry was also created, meshed and added to the CFD model. This CFD model was run in a transient mode to simulate the exact same flight conditions and APU operating points as were tested during the flight test. Dynamic results in the time and frequency domains predicted by the CFD analyses were compared to flight test data and correlation and calibration factors were derived.

A numerical model to evaluate the performance of pressure equalized rainscreen walls

Modelling of volatile organic compounds concentrations in rooms due to electronic devices