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عنوان فارسی مقاله:
آزمایش های آب شور با پرده هوا برای کنترل دود در صورت آتش سوزی
عنوان انگلیسی مقاله:
Saltwater experiments with air curtains for smoke control in the event of fire
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Smoke flow inside buildings is a major cause of fire casualties. The technology currently used to prevent these fatalities relies on the enclosure of building spaces by fire resistant walls, on the use of fire resistant doors and on the use of smoke control systems. In many cases, closing passageways with fire doors makes it difficult to identify the escape route and can delay people's egress; in other cases, the use of fire gates makes it difficult to use them as escape routes. When the fire propagation through the void is unlikely, it is acceptable to use an air curtain if effective for stopping the smoke flow. Air curtains do not impair the visibility of building occupants in evacuation and do not pose difficulties to people using escape routes. There are several applications of this concept in tunnels [1] and in building corridors [2], but these are based on the pull-push principle applied to horizontal air curtains. Several authors have studied the application of single vertical air curtains (upward or downward) [3–8] and a research work has been done about double vertical air curtains [9,12,16]. Some studies used CFD simulations to assess the performance of air curtains as regards curtain tightness in corridors [8], fire/ explosion accidents in a clean room [10], contaminant dispersion from clean rooms [11] and as regards curtain tightness in staircases [17]. The mentioned research work is not presenting clearly the need for smoke exhaustion in the fire compartment, which the author of this paper considers it to be a key issue for achieving smoke tightness by air curtains for high temperature smoke. Therefore, further research must be done on this topic in order to obtain a more generalized application of air curtains to the open boundaries of fire compartments. This project aims to develop and apply air curtain technology to limit smoke flow through the building openings. The methodology followed in this research includes: (i) the development of an analytical model that relates the relevant characteristic quantities of a plane jet with the characteristics of the environment in which the fire occurs, (ii) small scale experiments with saltwater modelling to assess the convective parameters that control smoke tightness of the curtain, (iii) CFD simulations to assess the performance of a full scale air curtain near a fire source and (iv) fire experiments with a full-scale test specimen. This paper addresses both the analytical model and the saltwater experiments. The analytical model assumes that the pressure due to the jet momentum balances the pressure due to buoyancy at the opening. This model also includes a simplified analytical methodology for estimating the temperature inside the fire compartment. Several vertical downward plane jets, vertical upward plane jets andhorizontal plane jets were tested on a small-scale model (1/20). However, just the vertical downward plane jets proved to be more efficient; therefore, only these results will be reported in this paper. Buoyancy due to fire was reproduced by the difference in density between saltwater and freshwater. The model, made by Plexiglas, includes one compartment connected to the exterior by a single opening, which is protected by the plane jet. The similarity laws between flows enable the extrapolation of these results to real fire cases.
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کلمات کلیدی:
Salt Water Density Experiment: 5 Steps (with Pictures) - Instructables www.instructables.com/id/Salt-Water-Density-Experiment/ Here's a brightly colored science experiment that not only looks cool, but allows students to develop their own understanding of density! I used this experiment ... Fresh and Salt Water Experiment | ASU - Ask A Biologist https://askabiologist.asu.edu/experiments/when-water-gets-icy If you've accidentally taken a sip of sea water or had to gargle with salt water, you've ... In this experiment, we will look at one major difference between frozen ... How to Turn Salt Water into Drinking Water | Activity | Education.com https://www.education.com › ... › Turn Salt Water into Drinking Water Do this experiment to help your first grader understand how salt can be removed from salt water. All it takes are a few household materials. Salt and Water Experiment - Kids Activities Blog kidsactivitiesblog.com › Kids Activities (by Age) › Elementary Activities Feb 11, 2012 - With this project, run an experiment to explore what happens when you place items in salt water, like the ocean vs. fresh water. What do you ... Saltwater Density Science Project - Home Science Tools https://www.homesciencetools.com/a/saltwater-density Is saltwater heavier than water? Why do you float in the Great Salt Lake? Find out in this experiment. Salt Water Experiment | Salts, For kids and Science experiments https://www.pinterest.com/pin/63402307233087405/ This super easy salt water experiment is the perfect science activity to teach kids about the density of salt and fresh water. Great for an ocean unit! Searches related to Saltwater experiments what floats in salt water and sinks in freshwater salt water experiment electricity salt water density experiment salt water density vs freshwater freezing salt water experiment experiments with salt and sugar salt water egg experiment salt water evaporation experiment
