BS ISO 19703-2006 en 4314 Generation and analysis of toxic gases - Calculation of species yields equivalence ratios and combustion efficiency in experimental fires《毒性气体生成和分析 实验室燃烧中.pdf

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1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58species yields, equivalence ratios and combustion efficiency in experimental fires ICS 13.220.01Gen

2、eration and analysis of toxic gases in fire Calculation of BRITISH STANDARDBS ISO19703:2005BS ISO 19703:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2006 BSI 2006ISBN 0 580 48903 5The British Standards which implement internati

3、onal publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include al

4、l the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a

5、 blank page, pages 1 to 34, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this committee can be obtained on request

6、to its secretary.Cross-referencesenquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 19703:2005 and implements it

7、 as the UK national standard.The UK participation in its preparation was entrusted to Technical Committee FSH/16, Hazards to life from fire, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any Reference numberISO 1970

8、3:2005(E)INTERNATIONAL STANDARD ISO19703First edition2005-05-01Generation and analysis of toxic gases in fire Calculation of species yields, equivalence ratios and combustion efficiency in experimental fires BS ISO 19703:2005ii iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Normative refere

9、nces . 1 3 Terms and definitions. 2 4 Symbols and abbreviated terms 4 5 Appropriate input data required for calculations 5 5.1 Data handling 5 5.2 Test specimen information 6 5.3 Fire conditions 6 5.4 Data collection. 7 6 Calculation of yields of fire gases and smoke, stoichiometric oxygen demand, a

10、nd recovery of key elements . 7 6.1 Calculation of measured yields from fire gas concentration data. 7 6.2 Calculation of notional gas yields. 10 6.3 Calculation of recovery of elements in key products . 13 6.4 Calculation of stoichiometric oxygen demand 13 6.5 Calculation of smoke yields. 20 7 Calc

11、ulation of equivalence ratio 23 7.1 General. 23 7.2 Derivation of for flow-through, steady-state experimental systems 24 7.3 Derivation of for flow-through, calorimeter experimental systems 25 7.4 Derivation of for closed chamber systems . 26 7.5 Derivation of in room fire tests . 26 8 Calculation o

12、f combustion efficiency . 26 8.1 General. 26 8.2 Heat release efficiency . 27 8.3 Oxygen consumption efficiency 28 8.4 Oxides of carbon method. 30 Bibliography . 34 BS ISO 19703:2005iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards b

13、odies (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 established has the right to be represented on that committee. International organizati

14、ons, 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 standardization. International Standards are drafted in accordance with the rules given in the

15、 ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of t

16、he member bodies casting a vote. 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. ISO 19703 was prepared by Technical Committee ISO/TC 92, Fire safety

17、, Subcommittee SC 3, Fire threat to people and environment. BS ISO 19703:2005vIntroduction It is the view of committees ISO TC92/SC3 (Fire threat to people and the environment), ISO TC92/SC4 (Fire safety engineering), and IEC TC89 (Fire hazard testing) that commercial products should not be regulate

18、d solely on the basis of the toxic potency of the effluent produced when the product is combusted in a bench-scale test apparatus (physical fire model). Rather, the information that characterizes the toxic potency of the effluent should be used in a fire risk or hazard assessment that includes the o

19、ther factors that contribute to determining the magnitude and impact of the effluent. The characterization of (a) the apparatus used to generate the effluent and (b) the effluent itself must thus be in a form usable in such a fire safety assessment. As described in ISO/TS 13571, the time to incapaci

20、tation in a fire is determined by the integrated exposure of a person to the fire effluent components. The toxic species concentrations depend on both the yields originally generated and the successive dilution in air. The former are commonly obtained using a bench-scale apparatus (in which a specim

21、en from a commercial product is burned) or a real-scale fire test of the commercial product. These yields, expressed as the mass of effluent component per mass of fuel consumed, are then inserted into a fluid mechanical model that estimates the transport and dilution of the effluent throughout the b

22、uilding as the fire evolves. For the engineering analysis to produce accurate results, the yield data must come from an apparatus that has been demonstrated to produce yields comparable to those produced when the full product is burned. In addition to depending on the chemical composition, conformat

23、ion and physical properties of the test specimen, toxic-product yields are sensitive to the combustion conditions in the apparatus. Thus, one means of increasing the likelihood that the yields from a bench-scale apparatus will be accurate is to operate it under combustion conditions similar to those

24、 expected when the real product burns. The important conditions include whether the fuel is flaming or non-flaming, the degree of flame extension, the fuel/air equivalence ratio, and the thermal environment. Similarly, these parameters should be known for a real-scale fire test. The yields of toxic

25、gases, the combustion efficiency and the equivalence ratio are likely to be sensitive to the manner in which the test specimen is sampled from the whole commercial product. There may be difficulty or alternative ways of obtaining of a proper test specimen. That is not the subject of this document, w

26、hich presumes that a specimen has been selected for study and characterizes the combustion conditions and the yields of effluent species for that specimen. For those experimental fires in which time-resolved data are available, the methods in this International Standard can be used to produce either

27、 instantaneous or averaged values. The application may be influenced by changes in the chemistry of the test specimen during combustion. For those fire tests limited to producing time-averaged gas concentrations, the calculated values produced by the methods in this International Standard are limite

28、d to being averages as well. In real fires, combustion conditions, the fuel chemistry and the composition of fire effluent from many common materials and products vary continuously during the course of the fire. Thus, how well the average yields obtained using these methods correspond to the yields

29、in a given real fire has much to do with the stage of the fire, the pace of fire development and the chemical nature of the materials and products exposed. This International Standard provides definitions and equations for the calculation of toxic product yields and the fire conditions under which t

30、hey have been derived in terms of equivalence ratio and combustion efficiency. Sample calculations for practical cases are provided. BS ISO 19703:2005blank1Generation and analysis of toxic gases in fire Calculation of species yields, equivalence ratios and combustion efficiency in experimental fires

31、 1 Scope This International Standard provides definitions and equations for the calculation of toxic product yields and the fire conditions under which they have been derived in terms of equivalence ratio and combustion efficiency. Sample calculations for practical cases are provided. The methods ca

32、n be used to produce either instantaneous or averaged values for those experimental fires in which time-resolved data are available. This International Standard is intended to provide guidance to fire researchers for appropriate experimental fire data to be recorded, calculating average yields of ga

33、ses and smoke in fire effluents in fire tests and fire-like combustion in reduced scale apparatus characterizing burning behaviour in experimental fires in terms of equivalence ratio and combustion efficiency using oxygen consumption and product generation data. This International Standard does not

34、provide guidance on the operating procedure of any particular piece of apparatus or interpretation of data obtained therein (e.g. toxicological significance of results). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated refere

35、nces, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5725-1:1994, Accuracy (trueness and precision) of measurements, methods and results Part 1: General principles and definitions ISO 5725-2:1994, Accuracy

36、 (trueness and precision) of measurements, methods and results Part 2: Basic methods for the determination of repeatability and reproducibility of a standard measurement method ISO/TR 9122-1:1989, Toxicity testing of fire effluents Part 1: General ISO/TR 9122-4:1993, Toxicity testing of fire effluen

37、ts Part 4: The fire model (furnaces and combustion apparatus used in small-scale testing) ISO/TS 13571, Life-threatening components of fire Guidelines for the estimation of time available for escape using fire data ISO/IEC 13943:2000, Fire safety Vocabulary BS ISO 19703:20052 ISO/TR 19701:1), Analyt

38、ical methods for fire effluents BIPM/IEC/IFCC/ISO/IUPAC/IUPAP/OIML, International vocabulary of basic and general terms in metrology (VIM), 1993 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 13943:2000 and the following apply. 3.1 atomic mass of an

39、 element value proportional to the mass of its atom relative to carbon (isotope 12C) that is assigned the value of 12,00 containing 1 mole of carbon atoms 3.2 combustion efficiency ratio of the heat released in a combustion reaction to the theoretical heat of complete combustion NOTE 1 Combustion ef

40、ficiency can be calculated only for cases where complete combustion can be defined. NOTE 2 Combustion efficiency can also be expressed as a percentage. 3.3 empirical formula chemical formula of a substance in which the relative numbers of atoms of each type are given NOTE Typically, the number for o

41、ne type of atom is chosen, to be an integer (usually C or O), e.g. a particular sample might be represented as C6H8,9O4,1N0,3Cl0,01. 3.4 equivalence ratio actual fuel-to-air mass ratio divided by the stoichiometric fuel-to-air mass ratio for that fuel NOTE 1 For 1, as in ventilation-controlled fires

42、, the mixture is fuel rich and relatively high concentrations of pyrolysis and incomplete combustion gases will result. NOTE 2 Standard, dry air contains 20,95 % oxygen by volume. In practice, the oxygen concentration in entrained air can vary, requiring correction in the calculation of to a standar

43、d, dry air basis. In this International Standard, fuel-to-oxygen ratios, rather than fuel/air ratios, are used for the equivalence ratio calculations. NOTE 3 For gaseous fuels, an alternative expression of the equivalence ratio can be based on the fuel-to-air volume ratio. 3.5 mass loss concentratio

44、n mass of a test specimen consumed during combustion per unit chamber volume (closed system) or per total volume of air passing through an open system NOTE 1 Mass loss concentration is typically expressed in units of grams per cubic metre. NOTE 2 For an open system, the definition assumes that the m

45、ass is dispersed in the air flow uniformly over time. 1) To be published. BS ISO 19703:200533.6 mass concentration of gas mass of gas per unit volume NOTE 1 The mass concentration of a gas can be derived from the measured volume fraction and its molar mass, or measured directly. NOTE 2 Mass concentr

46、ation is typically expressed in units of grams per cubic metre. 3.7 mass concentration of particles mass of solid and liquid aerosol particles per unit volume NOTE Mass concentration of particles is typically expressed in units of grams per cubic metre. 3.8 molar mass mass of 1 mole NOTE Molar mass

47、is normally expressed in units of grams per mole. 3.9 net heat of combustion enthalpy, per unit mass of fuel consumed, generated in complete combustion with the water produced being in the gaseous state NOTE Net heat of combustion is typically expressed in units of kilojoules per gram or megajoules

48、per kilogram. 3.10 notional yield stoichiometric yield maximum possible mass of a combustion product generated during combustion, per unit mass of test specimen consumed NOTE Notional yield is typically expressed in units of grams per gram or kilograms per kilogram. 3.11 recovery of element in a spe

49、cified combustion product degree of conversion of an element in the test specimen to a corresponding gas, i.e. a ratio of the actual yield to notional yield of the gas containing that element 3.12 stoichiomeric mixture mixture of fuel and oxidizer which has the correct composition to produce only the products of complete combustion 3.13 stoichiometric oxygen demand stoichiometric oxygen-to-fuel mass ratio amount of oxygen needed by a material for complete combustion NOTE Stoichiometric oxygen demand is typ