BS-EN-ISO-12213-3-2005.pdf

BRITISH STANDARD BS EN ISO 12213-3:2005 Incorporating Amendment No. 1 to BS ISO 12213-3:1997 (renumbers BS ISO as BS EN ISO 12213-3:2005) Natural gas Calculation of compression factor Part 3: Calculation using physical properties The European Standard EN ISO 12213-3:2005 has the status of a British Standard ICS 75.060 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 12213-3:2005 This British Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 April 1998 © BSI 17 February 2006 ISBN 0 580 29389 0 National foreword This British Standard is the English language version of EN ISO 12213-3:2005. It is identical with ISO 12213-3:1997. The UK participation in its preparation was entrusted to Technical Committee PTI/15, Natural gas and gas analysis, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European 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 all 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 pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii and iii, a blank page, pages 1 to 29 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No.DateComments 16148February 2006Renumbers BS ISO 12213-3:1997 as BS EN ISO 12213-3:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 12213-3:2005 © BSI 17 February 2006i Contents Page National forewordInside front cover ISO forewordiv Text of ISO 12213-31 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 12213-3 May 2005 ICS 75.060 English version Natural gas Calculation of compression factor Part 3: Calculation using physical properties (ISO 12213-3:1997) Gaz naturel Calcul du facteur de compression Partie 3: Calcul à partir des caractéristiques physiques (ISO 12213- 3:1997) Erdgas Berechnung von Realgasfaktoren Teil 3: Berechnungen basierend auf physikalischen Stoffeigenschaften als Eingangsgrößen (ISO 12213- 3:1997) This European Standard was approved by CEN on 17 April 2005. 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 references concerning such national standards may be obtained on application to the Central Secretariat 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 a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2005 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 12213-3:2005: E Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Foreword The text of ISO 12213-3:1997 has been prepared by Technical Committee ISO/TC 193, Natural gas, of the International Organization for Standardization (ISO) and has been taken over as EN ISO 12213-3:2005 by CMC. 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 November 2005, and conflicting national standards shall be withdrawn at the latest by November 2005. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 12213-3:1997 has been approved by CEN as EN ISO 12213-3:2005 without any modifications. EN ISO 12213-3:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 12213-3:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 12213-3:2005 ii © BSI 17 February 2006 Contents Page Forewordiv 1Scope1 2Normative references1 3Definitions1 4Method of calculation1 4.1Principle1 4.2The SGERG-88 equation2 4.3Input variables2 4.4Ranges of application3 4.5Uncertainty4 5Suppliers of computer programmes6 Annex A (normative) Symbols and units7 Annex B (normative) Description of the SGERG-88 method9 Annex C (normative) Example calculations18 Annex D (normative) Conversion factors18 Annex E (informative) Performance over wider ranges of application20 Annex F (informative) Subroutine SGERG.FOR in Fortran25 Annex G (informative) Bibliography29 Figure 1 Uncertainty limits for the calculation of compression factors5 Figure B.1 Flow diagram for standard GERG-88 calculation method 9 Figure B.2 Flow diagram for computing intermediate data by iteration11 Figure B.3 Flow diagram for compression factor calculation15 Figure E.1 Estimated uncertainty limits for the calculation of compression factors of natural gases with a high nitrogen content21 Figure E.2 Estimated uncertainty limits for the calculation of compression factors of natural gases with a high carbon dioxide content22 Figure E.3 Estimated uncertainty limits for the calculation of compression factors of natural gases with a high ethane content23 Figure E.4 Estimated uncertainty limits for the calculation of compression factors of natural gases with a high propane content24 Table 1 Uncertainties of input variables6 Table B.1 Values of the constants used in equation (B.1) 12 Table B.2 Numerical values for the coefficients b(0), b(1) and b(2) in the temperature expansion of the second virial coefficient for pure gases and of the unlike-interaction virial coefficients 14 Table B.3 Numerical values of the coefficients c(0), c(1) and c(2) in the temperature expansion of the third virial coefficient for pure gases and of the unlike-interaction virial coefficients 16 Table C.1 Input data18 Table C.2 Results (Z-values)18 Table D.1 Nationally adopted metric reference conditions for the measurement of calorific value19 Table D.2 Conversion factors for pressure and temperature19 Table D.3 Conversion factors for calorific value20 Table D.4 Conversion factors for calorific value and relative density20 Descriptors: Natural gas, compressed gas, compression, compression factor, rules of calculation. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 12213-3:2005 © BSI 17 February 2006iii Foreword ISO (the International 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 established 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 standardization. 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 the member bodies casting a vote. International Standard ISO 12213-3 was prepared by Technical Committee ISO/TC 193, Natural gas, Subcommittee SC 1, Analysis of natural gas. ISO 12213 consists of the following parts, under the general title Natural gas Calculation of compression factor. Part 1: Introduction and guidelines; Part 2: Calculation using molar-composition analysis; Part 3: Calculation using physical properties. Annex A to Annex D form an integral part of this part of ISO 12213. Annex E to Annex G are for information only. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 12213-3:2005 © BSI 17 February 20061 1 Scope This International Standard specifies methods for the calculation of compression factors of natural gases, natural gases containing a synthetic admixture and similar mixtures at conditions under which the mixture can exist only as a gas. This part of ISO 12213 specifies a method for the calculation of compression factors when the superior calorific value, relative density and carbon dioxide content are known, together with the relevant pressures and temperatures. If hydrogen is present, as is often the case for gases with a synthetic admixture, the hydrogen content also needs to be known. NOTE In principle, it is possible to calculate the compression factor when any three of the parameters superior calorific value, relative density, carbon dioxide content (the usual three) and nitrogen content are known, but subsets including nitrogen content are not recommended. The method is primarily applicable to pipeline quality gases within the ranges of pressure p and temperature T at which transmission and distribution operations normally take place, with an uncertainty of about ± 0,1 %. For wider-ranging applications the uncertainty of the results increases (see Annex E). More detail concerning the scope and field of application of the method is given in part 1 of this International Standard. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 12213. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 12213 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 31-3:1992, Quantities and units Part 3: Mechanics. ISO 31-4:1992, Quantities and units Part 4: Heat. ISO 6976:1995, Natural gas Calculation of calorific values, density, relative density and Wobbe index from composition. ISO 12213-1:1997, Natural gas Calculation of compression factor Part 1: Introduction and guidelines. 3 Definitions All definitions relevant to the use of this part of ISO 12213 are given in part 1. 4 Method of calculation 4.1 Principle The method recommended uses equations which are based on the concept that pipeline quality natural gas may be uniquely characterized for calculation of its volumetric properties by an appropriate and distinctive set of measurable physical properties. These characteristics, together with the pressure and temperature, are used as input data for the method. The method uses the following physical properties: superior calorific value, relative density and carbon dioxide content. The method is particularly useful in the common situation where a complete molar composition is not available, but may also be preferred for its relative simplicity. For gases with a synthetic admixture, the hydrogen content needs to be known. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 12213-3:2005 2 © BSI 17 February 2006 4.2 The SGERG-88 equation The calculation method using physical properties is based on the standard GERG 88 (SGERG-88) virial equation for natural gases 1, 2, 3. The standard GERG 88 virial equation is derived from the master GERG 88 (MGERG-88) virial equation, which is a method of calculation based on a molar-composition analysis 4. The SGERG-88 virial equation from which the compression factor Z is calculated may be written as where where However, the SGERG-88 method treats the natural-gas mixture internally as a five-component mixture consisting of an equivalent hydrocarbon gas (with the same thermodynamic properties as the sum of the hydrocarbons present), nitrogen, carbon dioxide, hydrogen and carbon monoxide. To characterize the thermodynamic properties of the hydrocarbon gas adequately, the hydrocarbon heating value HCH is also needed. Therefore, the calculation of Z uses In order to be able to model coke oven gas mixtures, the mole fraction of carbon monoxide is taken to have a fixed relation to the hydrogen content. If hydrogen is not present (xH2 0,01 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 15:55:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 12213-3:2005 18 © BSI 17 February 2006 Annex C (normative) Example calculations The following example calculations shall be used for the validation of computer implementations of the SGERG method not cited in Annex B. The calculations have been carried out using the validated executable programme GERG88.EXE, which incorporates the subroutine SGERG.FOR described in Anne