FprEN 16906

Liquid petroleum products - Determination of the ignition quality of diesel fuels - Fixed compression ratio engine method

This document specifies a test method for the determination of cetane numbers (“CN”) in diesel fuel, using a standard single cylinder, four-stroke cycle, indirect injection engine. The cetane number provides a measure of the ignition characteristics of diesel fuels in compression ignition engines. The cetane number is determined at constant speed in a compression ignition test engine equipped with a swirl chamber.
The cetane number scale covers the range from 0 to 100, but typical testing is performed in the range from about 40 CN to about 75 CN. The precision of this test method covers the range from 44 CN to about 66 CN.
This document is applicable to distillate as well as paraffinic diesel fuels intended for use in diesel engines, including those containing up to a volume fraction of 10 % fatty-acid methyl esters (FAME), ignition-improvers or other diesel fuel additives.
When this engine test procedure is used for other fuels such as synthetics and vegetable oils, samples with fuel properties that interfere with the gravity-based pre-supply pressure to the fuel pump e.g. due to high viscosity can only be used to a limited extent. Precision data for such fuels are not available at this stage.
NOTE   The test method is also suitable for determining cetane numbers outside the range of the scope; however, the precision statement only applies for fuels in the specified range.
WARNING - The use of this document can involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to take appropriate measures to ensure the safety and health of personnel prior to application of the document, and fulfil statutory and regulatory requirements for this purpose.

Flüssige Mineralölerzeugnisse - Bestimmung der Zündwilligkeit von Dieselkraftstoffen - Verfahren mit einem Prüfmotor mit konstantem Verdichtungsverhältnis

Dieses Dokument legt ein Prüfverfahren zur Bestimmung von Cetanzahlen („CZ“) in Dieselkraftstoffen unter Verwendung eines genormten Viertakt-Einzylindermotors mit indirekter Einspritzung fest. Die Cetanzahl gibt das Maß der Zündwilligkeit von Dieselkraftstoffen in Dieselmotoren an. Die Cetanzahl wird bei konstanter Drehzahl in einem mit einer Wirbelkammer ausgestatteten Prüfmotor mit Kompressionszündung bestimmt.
Der Skalenbereich der Cetanzahl deckt den Bereich von 0 bis 100 ab, allerdings wird die Prüfung üblicher-weise im Bereich von etwa 40 CZ bis etwa 75 CZ durchgeführt. Die Präzision dieses Prüfverfahrens deckt den Bereich von 44 CZ bis etwa 66 CZ ab.
Dieses Dokument ist anwendbar für Destillatkraftstoffe sowie für paraffinische Dieselkraftstoffe, die zur Verwendung in Dieselmotoren vorgesehen sind, einschließlich solcher, die Fettsäure-Methylester (en: fatty-acid methyl esters, FAME), Zündverbesserer oder andere Dieselkraftstoff-Additive bis zu einem Volumen¬anteil von 10 % enthalten.
Wenn dieses motorische Prüfverfahren für andere Kraftstoffe wie synthetische Produkte und Pflanzenöle angewendet wird, können Proben mit Brennstoffeigenschaften, die den Schwerkraft-Vorförderdruck zur Kraftstoffpumpe z. B. aufgrund einer hohen Viskosität stören, jedoch nur bedingt verwendet werden. Präzisionsdaten für derartige Kraftstoffe stehen zu diesem Zeitpunkt nicht zur Verfügung.
ANMERKUNG   Das Prüfverfahren ist auch zur Bestimmung von Cetanzahlen außerhalb der Reichweite des Anwendungsbereichs geeignet, allerdings gilt die Präzisionsaussage nur für Kraftstoffe innerhalb des angegebenen Bereichs.
WARNUNG - Die Anwendung dieses Dokuments kann die Anwendung gefährlicher Stoffe, Arbeitsgänge und Geräte mit sich bringen. Dieses Dokument beansprucht nicht, alle damit verbundenen Sicherheitsprobleme zu behandeln. Es liegt in der Verantwortung des Anwenders dieses Dokuments, vor der Anwendung geeignete Maßnahmen für die Sicherheit und den Gesundheitsschutz des Personals zu ergreifen und dafür Sorge zu tragen, dass behördliche und gesetzliche Maßnahmen eingehalten werden.

Produits pétroliers liquides - Détermination de la qualité d'allumage des combustibles Diesel - Méthode avec moteur à taux de compression fixe

Le présent document spécifie une méthode d'essai permettant de déterminer les indices de cétane (« IC ») des carburants pour moteurs diesel sur un moteur monocylindre classique à injection indirecte fonctionnant selon un cycle à 4 temps. L'indice de cétane fournit une mesure des caractéristiques d'inflammation des carburants diesel utilisés dans les moteurs à allumage par compression. L'indice de cétane est déterminé à vitesse de rotation constante, sur un moteur d'essai à allumage par compression équipé d'une chambre de turbulence.
L'échelle d'indice de cétane couvre la plage de 0 à 100, mais les essais classiques sont effectués entre IC 40 et IC 75 environ. La fidélité de la présente méthode d'essai couvre la plage d'IC 44 à IC 66 environ.
Le présent document s'applique aux distillats et aux carburants diesel paraffiniques destinés à être utilisés dans des moteurs diesel, y compris ceux contenant jusqu’à 10 % en volume d’esters méthyliques d'acides gras (EMAG), des activateurs d'allumage ou d'autres adjuvants de carburants pour moteurs diesel.
Lorsque ce mode opératoire est utilisé pour d'autres carburants tels que les produits de synthèse ou les huiles végétales, les échantillons composés de carburants dont les propriétés perturberaient la pression d'alimentation par gravité avant écoulement dans la pompe d'injection en raison, par exemple, d'une forte viscosité, ne peuvent être utilisés que dans des cas limités. Aucune valeur de fidélité n'est encore disponible à ce stade pour ces carburants.
NOTE    La méthode d'essai convient également pour déterminer les indices de cétane en dehors de l'intervalle du domaine d'application ; par contre les valeurs de fidélité établies dans ce document ne s'appliquent qu'aux carburants dans la gamme spécifiée.
ATTENTION - L'utilisation du présent document peut impliquer la mise en oeuvre de matériaux, d'opérations et de matériels dangereux. Le présent document ne prétend pas aborder tous les problèmes de sécurité associés à son utilisation. Il est de la responsabilité de l'utilisateur du présent document de prendre les mesures appropriées pour assurer la sécurité et préserver la santé du personnel avant l'application du présent document, et satisfaire aux exigences légales et réglementaires applicables à cet effet.

Tekoči naftni proizvodi - Ugotavljanje kakovosti vžiga dizelskih goriv - Motorna metoda s fiksnim kompresijskim razmerjem

General Information

• Status: Not Published
• Publication Date: 27-Sep-2023
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: CEN/TC 19 - Petroleum products, lubricants and related products
• Drafting Committee: CEN/TC 19/WG 35 - Ignition quality testing and correlation
• Current Stage: 5060 - Closure of Vote - Formal Approval
• Start Date: 03-Aug-2023
• Due Date: 15-Dec-2022
• Completion Date: 03-Aug-2023
• Ref Project: kSIST FprEN 16906:2023 - Liquid petroleum products - Determination of the ignition quality of diesel fuels - Fixed compression ratio engine method

Relations

• Revises: EN 16906:2017 - Liquid petroleum products - Determination of the ignition quality of diesel fuels - BASF engine method
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 16906:2022
01-april-2022
Tekoči naftni proizvodi - Ugotavljanje kakovosti vžiga dizelskih goriv - Motorna
metoda s fiksnim kompresijskim razmerjem
Liquid petroleum products - Determination of the ignition quality of diesel fuels - Fixed
compression ratio engine method
Flüssige Mineralölerzeugnisse — Bestimmung der Zündwilligkeit von Dieselkraftstoffen
— Verfahren mit einem Prüfmotor mit konstantem Verdichtungsverhältnis
Produits pétroliers liquides — Détermination de la qualité d'allumage des combustibles
Diesel — Méthode du moteur à taux de compression fixe
Ta slovenski standard je istoveten z: prEN 16906
ICS:
13.220.40 Sposobnost vžiga in Ignitability and burning
obnašanje materialov in behaviour of materials and
proizvodov pri gorenju products
75.160.20 Tekoča goriva Liquid fuels
oSIST prEN 16906:2022 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 16906:2022

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oSIST prEN 16906:2022


DRAFT
EUROPEAN STANDARD
prEN 16906
NORME EUROPÉENNE

EUROPÄISCHE NORM

April 2022
ICS 75.160.20 Will supersede EN 16906:2017
English Version

Liquid petroleum products - Determination of the ignition
quality of diesel fuels - Fixed compression ratio engine
method
Produits pétroliers liquides ¿ Détermination de la Flüssige Mineralölerzeugnisse - Bestimmung der
qualité d'allumage des combustibles Diesel ¿ Méthode Zündwilligkeit von Dieselkraftstoffen - Verfahren mit
du moteur à taux de compression fixe einem Prüfmotor mit konstantem
Verdichtungsverhältnis
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 19.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16906:2022 E
worldwide for CEN national Members.

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Contents Page
European foreword . Error! Bookmark not defined.
Introduction . Error! Bookmark not defined.
1 Scope . Error! Bookmark not defined.
2 Normative references . Error! Bookmark not defined.
3 Terms and definitions . Error! Bookmark not defined.
4 Principle . Error! Bookmark not defined.
5 Reagents and materials . Error! Bookmark not defined.
6 Apparatus . Error! Bookmark not defined.
6.1 General . Error! Bookmark not defined.
7 Sampling . Error! Bookmark not defined.
8 Standard operating and test conditions . Error! Bookmark not defined.
9 Calibration, verification and quality control. Error! Bookmark not defined.
10 Procedure. Error! Bookmark not defined.
10.1 Engine check and warm-up . Error! Bookmark not defined.
10.2 Bracketing procedure . Error! Bookmark not defined.
10.2.1 Unknown sample . Error! Bookmark not defined.
10.2.2 First primary reference fuel . Error! Bookmark not defined.
10.2.3 Second primary reference fuel . Error! Bookmark not defined.
10.2.4 Repeat readings . Error! Bookmark not defined.
10.3 Procedure using a calibration graph. Error! Bookmark not defined.
10.4 Shut-down of the engine . Error! Bookmark not defined.
11 Calculation . Error! Bookmark not defined.
11.1 Calculation for the bracketing procedure . Error! Bookmark not defined.
11.2 Calculation for the calibration graph . Error! Bookmark not defined.
12 Expression of results . Error! Bookmark not defined.
13 Precision . Error! Bookmark not defined.
13.1 General . Error! Bookmark not defined.
13.2 Repeatability . Error! Bookmark not defined.
13.3 Reproducibility . Error! Bookmark not defined.
Annex A (informative) Evaluation example of the cetane number using a calibration graph . Error!
Bookmark not defined.
Annex B (normative) Auxiliary digital equipment . Error! Bookmark not defined.
B.1 General . Error! Bookmark not defined.
B.2 Apparatus . Error! Bookmark not defined.
B.3 Set-up . Error! Bookmark not defined.
B.4 Calibration . Error! Bookmark not defined.
Bibliography . Error! Bookmark not defined.
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European foreword
This document (prEN 16906:2022) has been prepared by Technical Committee CEN/TC 19 “Gaseous and
liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”, the secretariat of
which is held by NEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 16906:2017.
The major updates towards the former version are:
— new title;
— new scope and precision based on proficiency testing scheme data within DIN-FAM;
— introduction of a new low cetane primary reference fuel, pentamethylheptane (PMH);
— introduction of a statistical observable bias with EN ISO 5165 in the expression of results section.
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Introduction
The test method described in this document is based on DIN 51773 [1], which had been developed in the
German group, DIN NA 062-06-43 AA “Engine testing of liquid fuels”, and which has been used very
successfully since more than 40 years. It was originally known as the 'BASF engine'.
The described method is an alternative quantitative determination of the cetane number of middle distillate
fuels intended for use in compression ignition engines.
A correlation study between this method and EN ISO 5165 [2] has been done and the results of this are
incorporated in the precision report issued in 2019 [3] and in this document.
The testing of pure FAME (which is in the scope of EN ISO 5165) has been excluded from the scope for the
time being as there seem to be sample specific biases for such product. CEN will initiate appropriate causal
studies.
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1 Scope
This document specifies a test method for the determination of cetane numbers (“CN”) in diesel fuel, using a
standard single cylinder, four-stroke cycle, indirect injection engine. The cetane number provides a measure
of the ignition characteristics of diesel fuels in compression ignition engines. The cetane number is determined
at constant speed in a compression ignition test engine equipped with a swirl chamber.
The cetane number scale covers the range from zero to 100, but typical testing is performed in the range from
about 40 CN to about 75 CN. The precision of this test method covers the range from 44 CN to about 66 CN.
This document is applicable to distillate as well as paraffinic diesel fuels intended for use in diesel engines,
including those containing fatty-acid methyl esters (FAME), ignition-improvers or other diesel fuel additives.
When this engine test procedure is used for other fuels such as synthetics and vegetable oils, samples with
fuel properties that interfere with the gravity-based pre-supply pressure to the fuel pump e.g. due to high
viscosity can only be used to a limited extent. Precision data for such fuels are not available at this stage.
NOTE 1 For the purpose of this document the expressions “%(m/m)” and “%(V/V)” are used to represent the mass
faction and volume fraction respectively of a material.
NOTE 2 The test method is also suitable for determining cetane numbers outside the range of the scope, however, the
precision statement only applies for fuels in the specified range.
WARNING — The use of this standard can involve hazardous materials, operations and equipment. This
standard does not purport to address all of the safety problems associated with its use. It is the responsibility
of the user of this standard to take appropriate measures to ensure the safety and health of personnel prior to
application of the standard, and fulfil statutory and regulatory requirements for this purpose.
2 Normative references
The following documents are referred to in the 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 undated references,
the latest edition of the referenced document (including any amendments) applies.
EN ISO 3170, Petroleum liquids - Manual sampling (ISO 3170)
EN ISO 3171, Petroleum liquids - Automatic pipeline sampling (ISO 3171)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
ignition quality
property of a fuel which causes a self-ignition under standard operating conditions in a diesel engine
3.2
ignition delay
ID
period of time between the start of fuel injection and the start of combustion expressed in degrees of crank
angle rotation
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3.3
cetane number
CN
measure of an ignition quality of a diesel fuel obtained by comparing it with reference fuel blends of known
cetane numbers and the fuel to be measured in a standardized test engine under controlled conditions
3.4
accepted reference value
ARV
value agreed upon as a reference for comparison
Note 1 to entry: The value is derived as (1) a theoretical or established value, based in scientific principles, (2) an
assigned value, based on experimental work of some national or international organization, or (3) a consensus value,
based on collaborative experimental work under the auspices of a scientific or engineering group.
4 Principle
The cetane number of a fuel is determined by comparing its combustion characteristics in a test engine with
those for blends of reference fuels of known cetane number under standard operating conditions. This is
accomplished by comparing the intake air mass at a given ignition delay. A multiple calibration procedure may
also be applied for the comparison of intake air mass.
5 Reagents and materials
5.1 Reference materials
NOTE Store and use primary reference fuels in the dark or in amber containers at temperatures of 20 °C or higher
to avoid solidification of n-Cetane which has a melting point of 18 °C.
5.1.1 n-hexadecane (n-Cetane), primary reference fuel
This reference material with a minimum purity of 99,0 %(m/m) shall be used as the designated cetane number
of 100. The purity shall be determined by a gas chromatography test method. An appropriate test method is
under development at DIN-FAM.
5.1.2 1-Methylnaphthalene (AMN), primary reference fuel
This reference material with a minimum purity of 95,0 %(m/m) shall be used as the designated cetane number
of zero. The purity shall be determined by a gas chromatography test method. An appropriate test method is
under development at DIN-FAM.
5.1.3 2,2,4,4,6,8,8-Heptamethylnonane (HMN), primary reference fuel
This reference material with a minimum purity of 98,0 %(m/m) shall be used as the designated cetane number
of 15. The purity shall be determined by a gas chromatography test method. An appropriate test method is
under development at DIN-FAM.
5.1.4 2,2,4,6,6-Pentamethylheptane (PMH), primary reference fuel
This reference material with a minimum purity of 98,0 %(m/m) shall be used as the designated cetane number
of 16,3. The purity shall be determined by a gas chromatography test method. An appropriate test method is
under development at DIN-FAM.
Primary reference fuel blends are volumetrically proportioned mixtures of these materials, which define the
CN scale.
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5.2 Reference fuel dispensing equipment
For preparing the required blends of reference fuels calibrated burettes or volumetric ware with a maximum
of 500 ml capacity and a maximum volumetric tolerance of ± 0,2 % shall be used. The burettes shall be
outfitted with a delivery valve and a delivery tip to accurately control the dispensed volumes. The delivery tip
shall be of such size and design that shut-off tip discharge does not exceed 0,5 ml. The rate of delivery from
the dispensing system shall not exceed 500 ml/min. The set of burettes or volumetric ware shall be installed
in such a manner that all components of each batch or blend are dispensed at the same temperature.
Other blending systems that allow the preparation of volumetrically-defined blends or volumetrically-defined
blends by gravimetric measurements based on the density of the individual components are also permitted,
provided the system meets the requirement for maximum 0,2 % tolerance limits.
5.3 Check fuels
Diesel fuels with known cetane number statistically validated by interlaboratory studies or proficiency testing
schemes (PTS) with other test engines may be used for checking the engine qualification only. The typical
cetane number range of a check fuel is from 44 CN to 66 CN which represents the Cetane number of diesel
fuels within the European market.
6 Apparatus
6.1 General
The 4-stroke single cylinder engine as shown in Figure 1 shall be used. It comprises a standard crankcase with
fuel pump assembly and a cylinder head assembly of the pre-combustion type, a thermal-siphon recirculating
jacket coolant system, double fuel tank system with selector valving, injector assembly with specific injector
nozzle, electrical controls and a suitable exhaust pipe.
NOTE The engine was developed by BASF SE on the basis of a MWM/KHD model KD12E engine.
The engine shall be connected to a special electric power-absorption motor, which acts as a motor driver to
start the engine and as a means to absorb power at constant speed when combustion is occurring.
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Key
1 air flow meter 4 assembly for fuel flow measurement
2 control device for start of injection and fuel amount 5 display for ignition delay
3 display for start of injection
Figure 1 — Test engine assembly
6.2 Mechanical equipment:
6.2.1 Fuel injection pump and nozzle.
The fuel injection pump including leakage oil stop, nozzle holding assembly and the injection nozzle.
NOTE The parts [BOSCH Type PE 1A M50, BOSCH KB 42 SDAV, BOSCH DLOS 103] which have proven to be suitable,
are trade names of a product supplied by BOSCH. This information is given for the convenience of users of this document
and does not constitute an endorsement by CEN or CENELEC of the product named. Equivalent products may be used if
they can be shown to lead to the same results e. g. by an interlaboratory study.
6.2.2 Injection-timing adjustment.
The fuel pump, installed on a panel, is driven by the camshaft and adjusted using an injection timing device.
6.2.3 Fuel flow measurement system.
To keep the fuel flow constant and to adjust the injected amount of fuel per pump stroke to the specified value
the control rod of the injection pump is equipped with a micro-adjustment. The fuel consumption shall be
measured by using two switchable burettes.
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