EN ISO 12213-3:2005
(Main)Natural gas - Calculation of compression factor - Part 3: Calculation using physical properties (ISO 12213-3:1997)
Natural gas - Calculation of compression factor - Part 3: Calculation using physical properties (ISO 12213-3:1997)
Erdgas - Berechnung von Realgasfaktoren - Teil 3: Berechnungen basierend auf physikalischen Stoffeigenschaften als Eingangsgrößen (ISO 12213-3:1997)
Gaz naturel - Calcul du facteur de compression - Partie 3: Calcul à partir des caractéristiques physiques (ISO 12213-3:1997)
Zemeljski plin – Izračun kompresijskega faktorja – 3. del: Izračun na podlagi fizikalnih lastnosti (ISO 12213-3:1997)
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2005
=HPHOMVNLSOLQ±,]UDþXQNRPSUHVLMVNHJDIDNWRUMD±GHO ,]UDþXQQDSRGODJL
IL]LNDOQLKODVWQRVWL ,62
Natural gas - Calculation of compression factor - Part 3: Calculation using physical
properties (ISO 12213-3:1997)
Erdgas - Berechnung von Realgasfaktoren - Teil 3: Berechnungen basierend auf
physikalischen Stoffeigenschaften als Eingangsgrößen (ISO 12213-3:1997)
Gaz naturel - Calcul du facteur de compression - Partie 3: Calcul a partir des
caractéristiques physiques (ISO 12213-3:1997)
Ta slovenski standard je istoveten z: EN ISO 12213-3:2005
ICS:
75.060 Zemeljski plin Natural gas
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN ISO 12213-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
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: Erdgas - Berechnung von Realgasfaktoren - Teil 3:
Calcul à partir des caractéristiques physiques (ISO 12213- Berechnungen basierend auf physikalischen
3:1997) 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.
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© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 12213-3:2005: E
worldwide for CEN national Members.
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.
INTERNATIONAL ISO
STANDARD 12213-3
First edition
1997-12-01
Natural gas — Calculation of compression
factor —
Part 3:
Calculation using physical properties
Gaz naturel — Calcul du facteur de compression —
Partie 3: Calcul au moyen des caractéristiques physiques
A
Reference number
ISO 12213-3:1997(E)
ISO 12213-3:1997(E)
Contents Page
1 Scope . 1
2 Normative references . 1
3 Definitions . 2
4 Method of calculation . 2
4.1 Principle . 2
4.2 The SGERG-88 equation . 2
4.3 Input variables . 3
4.4 Ranges of application . 3
4.5 Uncertainty . 4
5 Suppliers of computer programmes . 6
Annexes
A Symbols and units . 7
B Description of the SGERG-88 method . 9
C Example calculations . 18
D Conversion factors . 19
E Performance over wider ranges of application . 22
F Subroutine SGERG.FOR in Fortran . 26
G Bibliography . 30
© ISO 1997
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet central@iso.ch
X.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii
©
ISO ISO 12213-3:1997(E)
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
Annexes A to D form an integral part of this part of ISO 12213. Annexes E
to G are for information only.
iii
©
INTERNATIONAL STANDARD ISO ISO 12213-3:1997(E)
Natural gas — Calculation of compression factor —
Part 3:
Calculation using physical properties
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.
©
ISO
ISO 12213-3:1997(E)
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.
4.2 The SGERG-88 equation
The calculation method using physical properties is based on the standard GERG 88 (SGERG-88) virial equation
[1], [2], [3]
for natural gases . The standard GERG 88 virial equation is derived from the master GERG 88
[4]
(MGERG-88) virial equation, which is a method of calculation based on a molar-composition analysis .
The SGERG-88 virial equation from which the compression factor Z is calculated may be written as
ZB=+1 rr+C . . . (1)
mm
where
B and C are functions of the input data comprising the superior calorific value H , the relative density d, the
S
contents of both inert and combustible non-hydrocarbon components of the gas mixture (CO and H )
2 2
and the temperature T;
r is the molar density given by
m
r =pZ()RT . . . (2)
m
where
Z = f (p, T, H , d, x , x ) . . . (3)
1 S CO H
2 2
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 H is also needed. Therefore, the calculation of Z
CH
uses
Z = f ( , , , , , , , ) . . . (4)
p T H x x x x x
2 CH CH N2 CO2 H2 CO
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 ( 0,001), then set = 0. The natural-gas mixture
x < x
H2 H2
is then treated in the calculation method as a three-component mixture (see annex B).
The calculation is performed in three steps.
First, the five-component composition from which both the known superior calorific value and the known relative
density can be calculated satisfactorily may be found from the input data by an iterative procedure described in
detail in annex B.
©
ISO
ISO 12213-3:1997(E)
Secondly, once this composition is known, B and C may be found using relationships also given in annex B.
In the third step, equations (1) and (2) are solved simultaneously for r and Z by a suitable numerical method.
m
A flow diagram of the procedure for calculating Z from the input data is shown in figure B.1.
4.3 Input variables
4.3.1 Preferred input data set
The input variables required for use with the SGERG-88 equation are the absolute pressure, temperature and
superior calorific value (volumetric basis), the relative density, the carbon dioxide content and the hydrogen content.
Thus the physical properties used the input data set (set A) are
H , d, x and x
S CO H
2 2
Relative density is referred to normal conditions (101,325 kPa and 0 °C) and superior calorific value is referred to
normal conditions (101,325 kPa and 0 °C) and a combustion temperature of 25 °C.
4.3.2 Alternative input data sets
Three alternatives to the preferred input data set (see 4.3.1) may be used with the standard GERG virial equation:
x , H , d and x (set B)
N S H
2 2
x , x , d and x (set C)
N2 CO2 H2
x , x , H and x (set D)
N CO S H
2 2 2
[3]
The alternative input data sets are considered fully in GERG Technical Monograph TM5 . Use of the alternative
input data sets gives results which may differ at the fourth decimal place. This part of ISO 12213 recommends the
use of input data set A.
4.4 Ranges o
...
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