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1

Evaluation of the fire extinguishing effectiveness of sprinklers in fires of selected flammable materials using computer simulation method

Gałaj Jerzy, Smerdel Bartosz

Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej

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2025

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Nr 95 (tom 1)

89--122

EN

The main objective of this study was to analyse the feasibility of using PyroSim software to evaluate the extinguishing effectiveness of sprinklers in case of fires involving selected combustible materials, which are often found in modern interiors, such as polyurethane and pinewood. To perform numerical calculations, a geometric model of the computational domain, consisting of a selected room and its furnishings located at the Military University of Technology in Warsaw, was established. This model was parameterised and four thermocouples and two sprinklers were deployed. A numerical model of the combustion reaction of the selected combustible materials was also developed. This model was used to conduct numerical analyses for two selected sprinkler models from The Viking Corporation, Model M, and Grinnell, Model A. HRR fire rate curves, the total heat release curves, and the smoke distributions at 10, 20, 40, and 60 seconds of the fire duration, as well as the room temperature curves at 10, 30, and 60 second were obtained during simulation studies. Furthermore, also presented were the temperaturę curves recorded by the four thermocouples. Analyses of the obtained results enabled the assessment of the extinguishing effectiveness of the selected sprinklers and their impact on the combustion process of selected materials, and thus on the development and spread of fire hazards such as smoke and thermal impact. Based on the analysis, several conclusions have been formulated. It was found that both sprinklers used did not provide complete control of smoke spread, and that the Grinnell sprinklers were more effective in reducing temperature and overall heat release than the Viking sprinklers. Comparing the total heat released after 60 seconds, the Grinnell sprinklers were found to be approximately 40% more efficient than the Viking sprinklers. This is further confirmed by the fact that the maximum temperature recorded by thermocouple No. 1 was approximately 120°C lower during polyurethane combustion and approximately 150°C lower during pine wood combustion for the Grinnell sprinklers. This results from their faster activation due to their lower temperature threshold (57°C for the Grinnell and 68°C for the Viking) and the activation of two sprinklers rather than one within the assumed simulation window. Therefore, it is recommended to use the Grinnell model in situations requiring rapid and effective temperature control.

2

Comparison of different methods of extinguishing of the group A fire

Drzymała Tomasz, Mortka Piotr, Gałaj Jerzy

Materiały Budowlane

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2025

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nr 7

202--212

EN

The article presents a comparative analysis of various methods used in practice to extinguish group A fires in terms of their effectiveness and usefulness. The scope of the article includes performing tests of extinguishing group A fires, in accordance with the available methods discussed in Polish Standards. During the tests, various means were used to combat group A fires, including: ABC powder in a fire extinguisher and water supplied as a mist. Additionally, sprays, blankets and fire extinguishing sheets were used, as well as sorbent and CO2 and BC powder extinguishers. All tests were performed in accordance with the conditions of the PN-EN 3-7:2004+A1:2008 standard. This allowed obtaining comparable results. During the tests, the extinguishing effectiveness of water in the form of mist, extinguishing spray and ABC powder was confirmed. As an alternative extinguishing method, the best proved to be the application of a sheet and fire blankets, which effectively cut off the oxygen supply. The use of CO2 and BC powder extinguishers allowed for the delay of wood burning. The remaining extinguishing agents were ineffective as they did not fully extinguish the fire.

PL

W artykule przedstawiono analizę porównawczą różnych sposobów gaszenia pożarów grupy A stosowanych w praktyce pod względem ich skuteczności i przydatności. Zakres artykułu obejmuje badania gaszenia pożarów grupy A, zgodnie z dostępnymi metodami omówionymi w Polskich Normach. Podczas badań wykorzystane zostały różne środki mające na celu zwalczanie pożarów grupy A, m.in.: proszek ABC w gaśnicy oraz woda podawana jako mgła. Dodatkowo zastosowano spraye, koce i płachty gaśnicze, a także użyto sorbentu i gaśnic na CO2 oraz proszkowych BC. Wszystkie badania wykonano z zachowaniem warunków zgodnych z normą PN-EN 3-7:2004+A1:2008. Pozwoliło to na otrzymanie porównywalnych wyników. Podczas badań potwierdzono skuteczność gaśniczą wody w postaci mgły, sprayu gaśniczego oraz proszku ABC. Jako alternatywna metoda gaśnicza najlepiej sprawdziło się nakładanie płachty i koców gaśniczych, które skutecznie odcinały dopływ tlenu. Zastosowanie gaśnic na CO2 oraz gaśnic proszkowych BC spowodowało opóźnienie palenia się drewna. Pozostałe środki gaśnicze były nieskuteczne, ponieważ nie ugasiły w pełni pożaru.

3

Assessment of the impact of combustion of selected flammable materials on the possibility of evacuation in fire conditions

Gałaj Jerzy, Drzymała Tomasz, Smerdel Bartosz

Materiały Budowlane

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2025

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nr 10

119--132

EN

The main objective of this article was to assess the impact of combustion of selected flammable materials on the possibility of evacuation in fire conditions. To achieve this, a computer simulation method was used, using a tool dedicated to this type of research, the PyroSimprogram. Combustion tests were carried out on materials often used in modern rooms such as nylon, propylene, polyurethane, and pine and oak wood. A fire was assumed in the corner of a room with an area of approximately 22 m2 and a height of approximately 3.6 m with a ceiling beam and one column, as well as one door opening and six windows. The article presents the time histories of the heat release rate HRR and the total released heat Q_TOTAL during the combustion of selected materials. As a result of the simulation studies, spatial distributions of temperature and smoke were also obtained after 10, 20 and 30 seconds of simulation. Taking into account the recorded temperature distribution in the room and its smoke (except for pine wood), it can be stated that safe evacuation is only possible for the first 10 s. After this time, safe evacuation can only be carried out in a bent position with bent legs. Over time, you should move closer to the floor.

PL

Głównym celem artykułu było omówienie wpływu spalania wybranych materiałów palnych na możliwość ewakuacji w warunkach pożaru metodą symulacji komputerowej w programie PyroSim. Przeprowadzono badania spalania takich materiałów często wykorzystywanych we współczesnych pomieszczeniach, jak nylon, propylen, poliuretan oraz drewno sosnowe i dębowe. Założono pożar w rogu pomieszczenia o powierzchni ok. 22 m2 i wysokości ok. 3,6 m z belką stropową i jednym słupem, a także jednym otworem drzwiowym i sześcioma oknami. Zaprezentowano przebiegi czasowe szybkości wydzielania ciepła HRR oraz całkowitego wydzielonego ciepła Q_TOTAL podczas spalania wybranych materiałów. W wyniku badań symulacyjnych otrzymano również przestrzenne rozkłady temperatury i zadymienia po 10, 20 i 30 s symulacji. Biorąc pod uwagę zarejestrowany rozkład temperatury w pomieszczeniu oraz jego zadymienie stwierdzono, że bezpieczna ewakuacja jest możliwa tylko przez pierwsze 10 s. Po tym czasie może być prowadzona jedynie w pozycji pochylonej z ugiętymi nogami. Wraz z upływem czasu należy przyjmować pozycję bliższą podłogi.

4

Stochastic fire brigade intervention model

Kuziora Łukasz, Gałaj Jerzy

Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej

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2024

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Nr 91 (tom 1)

107--131

EN

The article is a continuation of a previously published paper, which, based on an analysis of available global literature, provides an overview of firefighting operational models. It outlines the concept of a stochastic model, which was implemented in the Aamks software to assess the fire risk of buildings, developed several years ago and systematically further expanded at the Fire University. It consists of four main time modules: the time of notifying about a fire, the time from receiving information about an incident until the moment of dispatch, the time of arriving at the scene of the incident and the time from the moment of arrival to the moment of starting firefighting activities. Their majority were determined in a probabilistic way, while some of them, such as the fire monitoring notification system and selected elements of the final stage, were assessed in a deterministic way. The paper discusses methods of their estimation, particularly in terms of the used data. The developed model consists of two main action phases, each subdivided into smaller stages, the sum of which gives the time taken to undertake extinguishing actions. This time is presented as a probability distribution. The first phase, i.e. the notification of the incident, is variable and depends on the equipment of the building with detection devices. As a result of the variability of the first phase of action, three different but invariable paths have been identified. The results in the form of extinguishing action times, along with the probabilities for each variant, are presented in three result tables at the end of the article.

5

Analysis of ignitability and combustion rate of selected interior furnishing materials

Gałaj Jerzy, Gruszczyński Przemysław

Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej

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2024

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Nr 91 (tom 1)

59--74

EN

The first part of the article presents the issue of apartment fires and describes materials used in the final stage of interior finishing. The second part discusses the research method and procedurę as well as the stand where, using two surface and edge methods in accordance with the PN-EN ISO 11925-2:2020 standard, the ignitability and burning rate of selected eight finishing materials, such as: laminated chipboard, varnished MDF, PVC wall panel, pine wooden board, ash wooden panel, carpet, laminated panel and vinyl panel, were determined. The test results are summarized in a table with the following values or answers to questions (Yes or No) for both methods used: whether ignition after 15 s, or ignition after 30 s, whether combustion was self-sustained, whether there were drops or waste, whether they caused ignition of the tissue paper, flame height after 20 s and 2 min. The last column contains the general characteristics of smoke released during combustion. Moreover, a separate table lists the average lengths of the burned sample and their linear burning velocities in the surface and edge methods for selected interior finishing materials. The study comprises an analysis of the obtained results, based on which several conclusions were formulated important from the viewpoint of fire safety of apartments. For example, it turned out that the highest combustion speed was observed in carpet samples and an ash wooden panel protected with clear varnish, while the lowest flame spread speed was recorded in the case of a vinyl panel and a varnished MDF board.

6

CFAST and FDS simulations of temperature in unsealed apartment – comparison of model results with experimental data

Saleta Damian, Gałaj Jerzy, Tuśnio Norbert

Materiały Budowlane

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2024

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nr 12

78--92

EN

This paper presents the validation of the CFAST and FDS models for a fire in an unsealed dwelling. The heat release rate was obtained from the Room Corner test and the experimental data from the full-scale fire test. The comparison concerned on the temperature distribution at selected points in the room. Two variants were used for the FDS simulation, the first with one fire source (an armchair) and no consideration of wind, and the second with two fire sources (an armchair and a sofa). In addition, the second variant used a 300-second delay for the second fire source and the wind, resulting from the full-scale fire observation. The accuracy of temperature mapping with both models depends on the location of the measuring point in relation to the fire source and the vents. Equally importantly, the representation of the temperature characteristics in the FDS field model can also be significantly improved by taking into account the wind and the additional fire area for a component that starts to burn after a certain time.

PL

W artykule przedstawiono walidację modeli CFAST i FDS w przypadku pożaru w rozszczelnionym mieszkaniu. Szybkość wydzielania ciepła otrzymano z testu Room Corner, a dane eksperymentalne z pełnoskalowego testu pożarowego. Porównanie dotyczyło rozkładu temperatury w wybranych punktach pomieszczenia. Do symulacji FDS zastosowano dwa warianty, pierwszy z jednym źródłem ognia (fotelem) i bez uwzględnienia wiatru oraz drugi z dwoma źródłami ognia (fotelem i kanapą). Ponadto, w wariancie drugim zastosowano 300-sekundowe opóźnienie drugiego źródła pożaru oraz wiejący wiatr, wynikające z obserwacji pożaru w pełnej skali. Dokładność odwzorowania temperatury za pomocą obu modeli zależy od lokalizacji punktu pomiarowego w stosunku do źródła pożaru i otworów wentylacyjnych. Odwzorowanie charakterystyki temperatury w modelu polowym FDS można znacznie poprawić przez uwzględnienie wiatru i dodatkowej powierzchni pożaru elementu, który zaczyna się palić po pewnym czasie.

7

Review of fire brigade extinguishment models as part of a building fire risk assessment

Kuziora Łukasz, Gałaj Jerzy

Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej

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2023

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Nr 88 (tom 1)

113--133

EN

This paper presents models of firefighting operations of fire brigades from the point of view of assessing the fire risk of buildings. The following seven related standards can be distinguished worldwide: International Fire Code (IFC), NFPA 5000: Building construction and safety code, International Fire Engineering Guidelines (IFEG), Fire Risk Evaluation and Cost Assessment Model (FireCAM), Fire Evaluation and Risk Assessment system (FIERA), PD 7974-5:2014 Application of Fire Safety Engineering Principles to the Design of Building; Part 5 Fire and Rescue Service Intervention as well as a Fire Brigade Intervention Model (FBIM). Given the editorial limitation as to the amount of text only the last one of them, which was used to the greatest extent in the construction of own model, was discussed in detail. The others have been discussed only in a general way. In the final part of the work, the existing models were evaluated as part of the discussion. On the basis of a critical review of literature and own research of the authors, a stochastic model of firefighting activities of fire brigades in Poland was developed, which will be one of vital elements of the Aamks software developed at the Fire University for assessing the fire risk of buildings. The description of this model along with the results of its operation and their discussion will be presented in the successive parts of the same series.

PL

W artykule przedstawiono modele działań gaśniczych jednostek straży pożarnej z punktu widzenia oceny zagrożenia pożarowego budynków. Na świecie można wyróżnić siedem powiązanych ze sobą norm: Międzynarodowy Kodeks Przeciwpożarowy (IFC), NFPA 5000: Kodeks konstrukcji budynków i bezpieczeństwa, Międzynarodowe Wytyczne Inżynierii Pożarowej (IFEG), Model oceny ryzyka pożarowego i kosztów (FireCAM), Ocena pożaru i System oceny ryzyka (FIERA), PD 7974-5:2014 Zastosowanie zasad inżynierii bezpieczeństwa pożarowego w projektowaniu budynków; Część 5 Interwencja Straży Pożarnej i Ratownictwa oraz Model Interwencji Straży Pożarnej (FBIM). Ze względu na redakcyjne ograniczenie objętości tekstu szczegółowo omówiono jedynie ostatni z nich, który w największym stopniu wykorzystano przy budowie własnego modelu. Pozostałe zostały omówione w sposób ogólny. W końcowej części pracy w ramach dyskusji dokonano oceny istniejących modeli. Na podstawie krytycznej analizy literatury oraz badań własnych opracowano stochastyczny model działalności straży pożarnej w Polsce, który będzie jednym z ważnych elementów tworzonego w Akademii Pożarniczej oprogramowania Aamks przeznaczonego do oceny ryzyka pożarowego budynków. Opis tego modelu wraz z wynikami jego działania i ich omówieniem zostanie przedstawiony w kolejnym artykule.