1、BS ISO 24678-6:2016Fire safety engineering Requirements governingalgebraic formulaePart 6: Flashover related phenomenaBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 24678-6:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation o
2、f ISO 24678-6:2016.The UK participation in its preparation was entrusted to TechnicalCommittee FSH/24, Fire safety engineering.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of
3、a contract. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 84703 5ICS 13.220.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the
4、 authority of theStandards Policy and Strategy Committee on 31 August 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 24678-6:2016 ISO 2016Fire safety engineering Requirements governing algebraic formulae Part 6: Flashover related phenomenaIngnierie de la scurit
5、 incendie Exigences rgissant les formules algbriques Partie 6: Phnomnes lis lembrasement gnralisINTERNATIONAL STANDARDISO24678-6First edition2016-08-01Reference numberISO 24678-6:2016(E)BS ISO 24678-6:2016ISO 24678-6:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Publis
6、hed in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permissio
7、n can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 24678-6:2016ISO 24678-6:2016(E)Fore
8、word ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Symbols . 25 Requirements governing description of physical phenomena . 26 Requirements governing documentation. 27 Requirements governing limitations 28 Requirements governing input parameters 39 Requirements gover
9、ning domain of applicability . 3Annex A (informative) Algebraic formulae for calculating the minimum heat release rate to cause flashover in residential size enclosures 4Bibliography .18 ISO 2016 All rights reserved iiiContents PageBS ISO 24678-6:2016ISO 24678-6:2016(E)ForewordISO (the International
10、 Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been est
11、ablished has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardiz
12、ation.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance w
13、ith the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
14、 patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.
15、For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.The com
16、mittee responsible for this document is ISO/TC 92, Fire safety, Subcommittee SC 4, Fire safety engineering.A list of all parts in the ISO 24678 series can be found on the ISO website.iv ISO 2016 All rights reservedBS ISO 24678-6:2016ISO 24678-6:2016(E)IntroductionThis document is intended to be used
17、 by fire safety practitioners involved with fire safety engineering calculation methods. Examples include fire safety engineers; authorities having jurisdiction such as: territorial authority officials, fire service personnel, code enforcers and code developers. It is expected that users of this doc
18、ument are appropriately qualified and competent in the field of fire safety engineering. It is particularly important that users understand the parameters within which particular methodologies may be used.Algebraic formulae conforming to the requirements of this document are used with other engineer
19、ing calculation methods during fire safety design. Such design is preceded by the establishment of a context, including the fire safety goals and objectives to be met, as well as performance criteria when a tentative fire safety design is subject to specified design fire scenarios. Engineering calcu
20、lation methods are used to determine if these performance criteria will be met by a particular design and if not, how the design must be modified.The subjects of engineering calculations include the fire-safe design of entirely new built environments, such as buildings, ships or vehicles as well as
21、the assessment of the fire safety of existing built environments.The algebraic formulae discussed in this document are very useful for estimating the consequences of design fire scenarios. Such formulae are particularly valuable for allowing the practitioner to quickly determine how a proposed fire
22、safety design should be modified to meet performance criteria. Thus, detailed numerical calculations can be delayed until final design documentation. Examples of areas where algebraic formulae have been applicable include determination of heat transfer, both convective and radiant, from fire plumes,
23、 prediction of ceiling jet flow properties governing detector response times, calculation of smoke transport through vent openings and analysis of compartment fire hazards such as smoke filling and flashover.With respect to flashover phenomena, algebraic formulae are often used to estimate the thres
24、hold (minimum) heat release rate required to produce flashover in the space under consideration. These estimates can suggest restrictions on flammable contents or an appropriate fire detection and suppression package to limit the maximum expected heat release rate to below that expected to produce f
25、lashover. These formulae are empirically developed from experiments done in relatively small rectilinear enclosures of similar size and with walls and ceilings of similar thermal properties. Thus, the calculated threshold flashover heat release rates do not incorporate the many variables that compli
26、cate enclosure fires. Consequently, these calculated values should be considered as preliminary estimates. Ultimately, these estimates can be useful for checking the results of zone and the more comprehensive numerical models that calculate fire growth and its consequences.ISO 23932 is supported by
27、a set of fire safety engineering documents available on the methods and data needed for the steps in a fire safety engineering design summarized in ISO 23932:2009, Clause 4 and shown in Figure 1 (taken from ISO 23932:2009, Clause 4). This set of documents is referred to as the Global Fire Safety Eng
28、ineering Analysis and Information System. This global approach and system of documents provides an awareness of the interrelationships between fire evaluations when using the set of fire safety engineering documents. The set includes ISO 16730-1, ISO 16732-1, ISO 16733-1, ISO 16734, ISO 16735, ISO 1
29、6736, ISO 16737, ISO/TS 13447, ISO/TS 24679, ISO/TS 29761 and other supporting technical reports that provide examples of and guidance on the application of these documents.Each document supporting the Global Fire Safety Engineering Analysis and Information System includes language in the introducti
30、on to tie said document to the steps in the fire safety engineering design process outlined in ISO 23932. ISO 23932 requires that engineering methods are selected properly to predict the fire consequences of specific scenarios and scenario elements (ISO 23932:2009, Clause 10). Pursuant to the requir
31、ements of ISO 23932, this document provides the requirement governing algebraic formulae for fire safety engineering. This step in the fire safety engineering process is shown as a highlighted box in Figure 1 and described in ISO 23932. ISO 2016 All rights reserved vBS ISO 24678-6:2016ISO 24678-6:20
32、16(E)NOTE From ISO 23932:2009, Clause 4.Figure 1 Fire-safety engineering process: Design, implementation and maintenance flowchartvi ISO 2016 All rights reservedBS ISO 24678-6:2016INTERNATIONAL STANDARD ISO 24678-6:2016(E)Fire safety engineering Requirements governing algebraic formulae Part 6: Flas
33、hover related phenomena1 ScopeThis document provides requirements to govern the application of explicit algebraic formula sets to the calculation of flashover-related phenomena.This document is an implementation of the general requirements provided in ISO 16730-1 for the case of fire dynamics calcul
34、ations involving sets of explicit algebraic formulae.This document is arranged in the form of a template, where specific information relevant to algebraic flashover formulae are provided to satisfy the following types of general requirements:a) description of physical phenomena addressed by the calc
35、ulation method;b) documentation of the calculation procedure and its scientific basis;c) limitations of the calculation method;d) input parameters for the calculation method;e) domain of applicability of the calculation method.Annex A contains a set of algebraic formulae each of which calculate the
36、minimum heat release rate to cause flashover in residential size enclosures.2 Normative referencesThe following documents are referred to in text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undat
37、ed references, the latest edition of the referenced document (including any amendments) applies.ISO 16730-1, Fire safety engineering Procedures and requirements for verification and validation of calculation methods Part 1: General3 Terms and definitionsFor the purposes of this document, the terms a
38、nd definitions given in ISO 13943 and the following shall apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp ISO 2016 Al
39、l rights reserved 1BS ISO 24678-6:2016ISO 24678-6:2016(E)3.1critical heat release rate for flashoverminimum heat release rate of a fire in an enclosure to cause flashover in that enclosure4 Symbols Symbols for the calculations used to predict flashover onset in Annex A are listed in A.2.5 Requiremen
40、ts governing description of physical phenomena5.1 The onset of flashover is a complex thermo-physical phenomenon that can be highly transient. As a result of burning in an enclosure, hot smoke layer develops in the upper part as stated in ISO 16735. Heat and mass transfer in enclosure takes place. R
41、adiative and convective heat transfer to fuel surface may increase the heat release rate. To calculate the onset of flashover, interactions between phenomena should be considered.5.2 Flashover phenomena to be calculated and their useful ranges shall be clearly identified, including those characteris
42、tics inferred by association with calculated quantities.5.3 Scenario elements (e.g. two-layer environment) to which specific formulae apply shall be clearly identified.5.4 Because different formulae describe different flashover characteristics (5.2) or apply to different scenarios (5.3), it shall be
43、 shown that if there is more than one method to calculate a given quantity, guidance shall be given on the selection of appropriate methods. A descriptive example is given in Annex A.6 Requirements governing documentation6.1 The procedure to be followed in performing calculations shall be described
44、through a set of algebraic formulae.6.2 Each formula shall be presented in a separate clause containing a phrase that describes the output of the formula, as well as explanatory notes and limitations unique to the formula being presented.6.3 Each variable in the formula set shall be clearly defined,
45、 along with appropriate SI units, although formula versions with dimensionless coefficients are preferred.6.4 The scientific basis for the formula set shall be provided through reference to recognized handbooks, the peer-reviewed scientific literature or through derivations, as appropriate.6.5 Examp
46、les shall demonstrate how the formula set is evaluated using values for all input parameters consistent with the requirements in Clause 6.7 Requirements governing limitations7.1 Quantitative limits on direct application of the algebraic-formula set to calculate output parameters, consistent with the
47、 scenarios described in Clause 6, shall be provided.7.2 Cautions on the use of the algebraic-formula set within a more general calculation method shall be provided, which shall include checking of consistency with the other relations used in the calculation method and the numerical procedures employ
48、ed.2 ISO 2016 All rights reservedBS ISO 24678-6:2016ISO 24678-6:2016(E)8 Requirements governing input parameters8.1 Input parameters for the set of algebraic-formulae shall be identified clearly, such as; geometric dimensions of enclosure surfaces and vents, special location of vents, special locati
49、on of fire source, physical properties of boundaries, combustion properties and so on.8.2 Sources of data for input parameters shall be identified or provided explicitly within the document.8.3 The valid ranges for input parameters shall be listed as specified in ISO 16730-1.9 Requirements governing domain of applicability9.1 One or more collections of measurement data shall be identified to establish the domain of applicability of the formula-set. These data shall have certain level of quality e.g. repeatability and reprodu
