1、September 2014 Translation by DIN-Sprachendienst.English price group 22No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).
2、ICS 75.060!%:V“2235851www.din.deDDIN EN ISO 15971Natural gas Measurement of properties Calorific value and Wobbe index (ISO 15971:2008);English version EN ISO 15971:2014,English translation of DIN EN ISO 15971:2014-09Erdgas Messung der Eigenschaften Wrmewerte und Wobbe-Index (ISO 15971:2008);Englisc
3、he Fassung EN ISO 15971:2014,Englische bersetzung von DIN EN ISO 15971:2014-09Gaz naturel Mesurage des proprits Pouvoir calorifique et indice de Wobbe (ISO 15971:2008);Version anglaise EN ISO 15971:2014,Traduction anglaise de DIN EN ISO 15971:2014-09www.beuth.deDocument comprises 58 pagesIn case of
4、doubt, the German-language original shall be considered authoritative.08.14 DIN EN ISO 15971:2014-09 2 A comma is used as the decimal marker. National foreword The text of ISO 15971:2008 has been prepared by Technical Committee ISO/TC 193 “Natural gas” (Secretariat: NEN, Netherlands) and has been ta
5、ken over by Technical Committee CEN/SS N21 “Gaseous fuels and combustible gas” as EN ISO 15971:2014. The responsible German body involved in its preparation was the Normenausschuss Gastechnik (DIN Standards Committee Gas Technology), Working Committee NA 032-03-05 AA Gasfrmige Brennstoffe. There is
6、no previous edition of this standard. The text of ISO 15971:2008 has been adopted without any modification. DIN EN ISO 15971:2014-09 3 National Annex NA (informative) Bibliography DIN EN ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-sectio
7、n conduits running full Part 1: General principles and requirements DIN EN ISO 6976, Natural gas Calculation of calorific values, density, relative density and Wobbe index from composition DIN EN ISO 10715, Natural gas Sampling guidelines DIN EN ISO 12213-1, Natural gas Calculation of compression fa
8、ctor Part 1: Introduction and guidelines DIN EN ISO 12213-2, Natural gas Calculation of compression factor Part 2: Calculation using molar-composition analysis DIN EN ISO 12213-3, Natural gas Calculation of compression factor Part 3: Calculation using physical properties DIN EN ISO 14532, Natural ga
9、s Vocabulary E DIN EN 1776:2014-01, Gas infrastructure Gas measuring systems Functional requirements DIN EN 60079-0, Explosive atmospheres Part 0: Equipment General requirements DIN EN 60079-1, Explosive atmospheres Part 1: Equipment protection by flameproof enclosures “d” DIN EN 60079-11, Explosive
10、 atmospheres Part 11: Equipment protection by intrinsic safety “i” DIN EN 60079-14, Explosive atmospheres Part 14: Electrical installations design, selection and erection DIN EN 60079-15, Explosive atmospheres Part 15: Equipment protection by type of protection “n” DIN EN 60751, Industrial platinum
11、resistance thermometers and platinum temperature sensors DIN EN 60770-1, Transmitters for use in industrial-process control systems Part 1: Methods for performance evaluation DIN EN 60770-2, Transmitters for use in industrial-process control systems Part 2: Methods for inspection and routine testing
12、 DIN IEC 60381-1, Analogue signals for process control systems Part 1: Direct current signals DIN IEC 60381-2, Analogue signals for process control systems Part 2: Direct voltage signals BS 1042-1.4: Measurement of fluid flow in closed conduits. Pressure differential devices. Guide to the use of dev
13、ices specified in sections 1.1 and 1.2 (withdrawn) see: DIN EN ISO 5167-1; Measurement of fluid flow by means of pressure differential devices Part 1: Orifice plates, nozzles and Venturi tubes inserted in circular cross-section conduits running full DIN 1871, Gaseous fuels and other gases Density an
14、d other volumetric quantities DIN EN ISO 15971:2014-09 4 ISO 4006:1991, Measurement of fluid flow in closed conduits Vocabulary and symbols, see: DIN EN 24006:1993-08, Measurement of fluid flow in closed conduits Vocabulary and symbols EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 15971 M
15、arch 2014 ICS 75.060 English Version Natural gas - Measurement of properties - Calorific value and Wobbe index (ISO 15971:2008) Gaz naturel - Mesurage des proprits - Pouvoir calorifique et indice de Wobbe (ISO 15971:2008) Erdgas - Messung der Eigenschaften - Wrmewerte und Wobbe-Index (ISO 15971:2008
16、) This European Standard was approved by CEN on 16 February 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical
17、references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of
18、a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Mace
19、donia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUR
20、OPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 15971:2014 EContents Page Foreword. 3 Introduction 4 1 Scope . 5 2 Normative refe
21、rences . 5 3 Terms and definitions. 5 3.1 Calorific value and Wobbe index 5 3.2 Water content of gas 6 3.3 Performance classification 6 3.4 Terms from metrology 7 4 Principles of measurement 8 4.1 Introduction . 8 4.2 Direct combustion calorimetry 9 4.3 Indirect methods. 9 4.4 Inferential methods. 1
22、0 5 Performance assessment and acceptance tests. 11 5.1 Performance assessment for instrument selection 11 5.2 Factory and site acceptance tests 24 6 Sampling and installation guidelines . 25 6.1 Sampling 25 6.2 Installation guidelines 26 7 Calibration . 29 7.1 Calibration procedures. 29 7.2 Calibra
23、tion gases 30 8 Verification 31 8.1 Verification procedures 31 8.2 Verification gases . 32 9 Maintenance 33 9.1 Preventive maintenance. 33 9.2 Corrective maintenance . 33 10 Quality control. 33 10.1 General. 33 10.2 Environmental parameters and ancillary equipment 35 10.3 Instrumental factors . 36 A
24、nnex A (normative) Symbols and units. 37 Annex B (informative) Examples of type-approval and technical specifications 38 Annex C (informative) Class 0 mass-basis calorimetry . 40 Annex D (informative) Direct combustion calorimetry. 44 Annex E (informative) Stoichiometric combustion devices. 47 Annex
25、 F (informative) Effect of non-alkane gases on stoichiometric combustion devices. 51 Annex G (informative) Measurement of Wobbe index 52 Bibliography . 53 DIN EN ISO 15971:2014-09 EN ISO 15971:2014 (E) 2 Foreword The text of ISO 15971:2008 has been prepared by Technical Committee ISO/TC 193 “Natural
26、 gas” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 15971:2014. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2014, and conflicting nati
27、onal standards shall be withdrawn at the latest by September 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CE
28、N-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hunga
29、ry, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 15971:2008 has been approved by CEN as EN ISO 15971:2014 without any mo
30、dification. DIN EN ISO 15971:2014-09 EN ISO 15971:2014 (E) 3 Introduction The amount of energy delivered by a flowing natural gas is often determined as the product of the volume delivered and the calorific value per unit volume of the gas. It is, therefore, important to have available standardized
31、methods of determining the calorific value. In many cases, it is possible to calculate the calorific value of natural gas, with sufficient accuracy, given the composition (see ISO 6976). However, it is also possible, and sometimes a preferred alternative, to measure calorific value using any one of
32、several techniques that do not require a compositional analysis. The methods currently in use, and the many factors that it is necessary to address in the selection, evaluation, performance assessment, installation and operation of a suitable instrument, are detailed herein. The measurement of the W
33、obbe index, a property closely related to calorific value, is discussed briefly in an informative annex, but is not considered in detail in the normative parts of this International Standard. DIN EN ISO 15971:2014-09 EN ISO 15971:2014 (E) 4 1 Scope This International Standard concerns the measuremen
34、t of calorific value of natural gas and natural gas substitutes by non-separative methods, i.e. methods that do not involve the determination of the gas composition nor calculation from it. It describes the principles of operation of a variety of instruments in use for this purpose, and provides gui
35、delines for the selection, evaluation, performance assessment, installation and operation of these. Calorific values can be expressed on a mass basis, a molar basis or, more commonly, a volume basis. The working range for superior calorific value of natural gas, on the volume basis, is usually betwe
36、en 30 MJ/m3and 45 MJ/m3at standard reference conditions (see ISO 13443). The corresponding range for the Wobbe index is usually between 40 MJ/m3and 60 MJ/m3. This International Standard neither endorses nor disputes the claims of any commercial manufacturer for the performance of an instrument. Its
37、central thesis is that fitness-for-purpose in any particular application (defined in terms of a set of specific operational requirements) can be assessed only by means of a well-designed programme of experimental tests. Guidelines are provided for the proper content of these tests. 2 Normative refer
38、ences The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 6976:1995, Natural gas Calculation of c
39、alorific values, density, relative density and Wobbe index from composition ISO 14532: 2001, Natural gas Vocabulary 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 Calorific value and Wobbe index 3.1.1 superior calorific value amount of heat
40、that would be released by the complete combustion in air of a specified quantity of gas (on a molar, mass or volume basis), in such a way that the pressure, p, at which the reaction takes place remains constant and all the products of combustion are returned to the same specified temperature, T, as
41、that of the reactants, all of these products being in the gaseous state, except for water formed by combustion, which is condensed to the liquid state at T See ISO 6976. DIN EN ISO 15971:2014-09 EN ISO 15971:2014 (E) 5 3.1.2 inferior calorific value amount of heat that would be released by the compl
42、ete combustion in air of a specified quantity of gas (on a molar, mass or volume basis), in such a way that the pressure, p, at which the reaction takes place remains constant, and all the products of combustion are returned to the same specified temperature, T, as that of the reactants, all of thes
43、e products being in the gaseous state See ISO 6976. 3.1.3 Wobbe index superior calorific value on a volumetric basis at specified reference conditions, divided by the square root of the relative density at the same specified metering reference conditions See ISO 6976. 3.1.4 standard reference condit
44、ions temperature, T = 288,15 K, and (absolute) pressure, p = 101,325 kPa, for the real dry gas See ISO 13443. NOTE Standard reference (or base) conditions of temperature, pressure and humidity (state of saturation) are defined for use only in natural gas and similar applications. For the calorific v
45、alue on a volumetric basis, these conditions apply to both the metering and combustion of the gas. In the expression of physical quantities throughout this International Standard, these standard reference conditions as defined in ISO 13443 are taken to apply. 3.2 Water content of gas 3.2.1 saturated
46、 gas natural gas which, at the specified conditions of temperature and pressure, is at its water dew-point 3.2.2 dry gas natural gas which does not contain water vapour at a mole fraction greater than 0,000 05 See ISO 6976. 3.2.3 partially saturated or wet gas natural gas which contains an amount of
47、 water vapour between that of the saturated gas and that of the dry gas, at the specified conditions of temperature and pressure 3.3 Performance classification NOTE The following classification scheme is adopted in order to categorize the uncertainties associated with measurement of calorific value. The attached notes are explanatory, not parts of the definitions. The values given refer to an expanded uncertainty with a coverage factor of 2. 3.3.1 class 0 performance with whic
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