SIST EN 15195:2007
(Main)Liquid petroleum products - Determination of ignition delay and derived cetane number (DCN) of middle distillate fuels by combustion in a constant volume chamber
Liquid petroleum products - Determination of ignition delay and derived cetane number (DCN) of middle distillate fuels by combustion in a constant volume chamber
This document specifies a test method for the quantitative determination of ignition delay of middle distillate fuels intended for use in compression ignition engines. The method utilizes a constant volume combustion chamber designed for operation by compression ignition, and employing direct injection of fuel into compressed air that is controlled to a specified pressure and temperature. An equation is given to calculate the derived cetane number (DCN) from the ignition delay measurement.
This standard is applicable to diesel fuels, including those containing FAME. The method is also applicable to middle distillate fuels of non-petroleum origin. However, users applying this standard especially to unconventional diesel fuels are warned that the relationship between derived cetane number and combustion behaviour in real engines is not yet fully understood. The standard covers the ignition delay range from 3,3 ms to 6,4 ms (61 DCN to 34 DCN). The combustion analyser can measure shorter or longer ignition delays, but precision can be affected.
NOTE For the purpose of this European Standard, the expression “% (V/V)” is used to represent the volume fraction and “% (m/m)” the mass fraction.
WARNING — The use of this standard may 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 establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Flüssige Mineralölerzeugnisse - Bestimmung des Zündverzugs und der abgeleiteten Cetanzahl (ACZ) von Kraftstoffen aus Mitteldestillaten in einer Verbrennungskammer mit konstantem Volumen
Dieses Dokument legt ein Prüfverfahren fest zur quantitativen Bestimmung des Zündverzugs von Kraftstoffen aus Mitteldestillaten, für Dieselmotoren. Das Verfahren benutzt eine Verbrennungskammer mit konstantem Volumen, die für den Betrieb durch Selbstzündung ausgelegt ist, und es setzt direkte Kraftstoffeinspritzung in komprimierte Luft ein, die auf vorgeschriebene Druck- und Temperaturwerte eingestellt wird. Eine Gleichung zur Berechnung der abgeleiteten Cetanzahl (ACZ) aus der Messung des Zündverzugs wird angegeben.
Diese Norm ist anwendbar auf Kraftstoffe auf Mineralölbasis, einschließlich FAME-haltiger, und auf solche, die nicht aus Mineralöl hergestellt werden. Die Anwender werden jedoch darauf hingewiesen, dass die Beziehung zwischen der abgeleiteten Cetanzahl und dem Verbrennungsverhalten solcher unkonventioneller Kraftstoffe in realen Motoren noch nicht völlig geklärt ist. Das Verfahren ist für einen Bereich des Zündverzugs von 3,3 ms bis 6,4 ms (ACZ von 62 bis 34) anwendbar.
ANMERKUNG Für den Zweck dieser Europäischen Norm darf das Symbol %(V/V) verwendet werden, um Volumenanteile in % und das Symbol %(m/m), um Massenanteile in % auszudrücken.
WARNUNG Die Anwendung dieser Europäischen Norm kann den Einsatz gefährlicher Stoffe, Arbeitsgänge und Geräte mit sich bringen. Diese Norm gibt nicht vor, alle mit ihrer Anwendung verbundenen Sicherheitsprobleme anzusprechen. Der Anwender dieser Norm ist dafür verantwortlich, vorher angemessene Maßnahmen zu ergreifen und die Anwendbarkeit einschränkender Vorschriften zu ermitteln.
Produits pétroliers liquides - Détermination du délai d'inflammation et de I'indice de cétane dérivé (ICD) des distillats moyens par combustion dans une enceinte a volume constant
Le présent document prescrit une méthode d'essai pour la détermination quantitative du délai d’inflammation
des distillats moyens utilisés comme carburants dans des moteurs a allumage par compression. Elle utilise
une chambre de combustion a volume constant conçue pour la mise en oeuvre d'un allumage par
compression avec l'injection directe du carburant dans de l'air comprimé maintenu a une pression et une
température données. Une équation est présentée pour calculer l'indice de cétane dérivé (ICD) a partir du
délai d’inflammation mesuré.
La présente norme est applicable aux carburants diesels, y compris ceux qui contiennent des EMAG. Elle est
applicable aussi a des distillats moyens d'origine non pétroliere. Pourtant l'attention des utilisateurs est attirée
sur le fait que les relations entre les caractéristiques d'inflammation des carburants non conventionnels et les
performances des moteurs ne sont pas encore completement élucidées. La méthode est applicable dans un
domaine de délai d’inflammation allant de 3,3 ms a 6,4 ms (soit un ICD de 62 a un ICD de 34). L’analyseur de
combustion peut mesurer des délais d’inflammation plus courts ou plus longs mais la fidélité peut s’en trouvée
modifiée.
NOTE Pour les besoins de la présente Norme européenne, les expressions "% (m/m)" et "% (V/V)" représentent
respectivement les fractions massiques et volumiques.
AVERTISSEMENT - L'utilisation de la présente Norme européenne peut impliquer l'intervention de
produits, d'opérations et d'équipements a caractere dangereux. La présente norme européenne n'est
pas censée aborder tous les problemes de sécurité concernés par son usage. Il est de la
responsabilité de l'utilisateur de consulter et d'établir des regles de sécurité et d'hygiene appropriées
et de déterminer l'applicabilité des restrictions réglementaires avant utilisation.
Tekoči naftni proizvodi – Ugotavljanje zakasnitve vžiga in izpeljanega cetanskega števila (DCN) v srednje destilatnih gorivih s konstantno prostornino
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.LQRFlüssige Mineralölerzeugnisse - Bestimmung des Zündverzugs und der abgeleiteten Cetanzahl (ACZ) von Kraftstoffen aus Mitteldestillaten in einer Verbrennungskammer mit konstantem VolumenProduits pétroliers liquides - Détermination du délai d'inflammation et de I'indice de cétane dérivé (ICD) des distillats moyens par combustion dans une enceinte a volume constantLiquid petroleum products - Determination of ignition delay and derived cetane number (DCN) of middle distillate fuels by combustion in a constant volume chamber75.160.20Liquid fuelsICS:Ta slovenski standard je istoveten z:EN 15195:2007SIST EN 15195:2007en,fr01-junij-2007SIST EN 15195:2007SLOVENSKI
STANDARD
SIST EN 15195:2007
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15195April 2007ICS 75.160.20 English VersionLiquid petroleum products - Determination of ignition delay andderived cetane number (DCN) of middle distillate fuels bycombustion in a constant volume chamberProduits pétroliers liquides - Détermination du délaid'inflammation et de I'indice de cétane dérivé (ICD) desdistillats moyens par combustion dans une enceinte àvolume constantFlüssige Mineralölerzeugnisse - Bestimmung desZündverzugs und der abgeleiteten Cetanzahl (ACZ) vonKraftstoffen aus Mitteldestillaten in einerVerbrennungskammer mit konstantem VolumenThis European Standard was approved by CEN on 8 March 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2007 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15195:2007: ESIST EN 15195:2007
EN 15195:2007 (E) 2 Contents Page Foreword.3 Introduction.4 1 Scope.5 2 Normative references.5 3 Terms and definitions.5 4 Symbols and abbreviations.6 5 Principle.7 6 Reagents and materials.7 7 Apparatus.8 7.1 Combustion analyzer.8 7.2 Filter medium.8 8 Sampling.10 9 Apparatus assembly and installation.10 10 Preparation of apparatus.11 10.1 System start-up and warm-up.11 10.2 Standard operating conditions.11 10.3 Standard test conditions.11 10.4 Final check.12 11 Calibration, verification and quality control.12 11.1 General.12 11.2 Calibration.12 11.3 Apparatus verification.13 11.4 Quality control (QC).13 12 Test procedure.13 13 Calculation.14 14 Expression of results.14 15 Precision.14 15.1 General.14 15.2 Repeatability.14 15.3 Reproducibility.14 16 Test report.15 Annex A (normative)
Test apparatus description.16 Annex B (normative)
Operational details in support to the standard test procedure.19 Annex C (informative)
Apparatus maintenance.22 Bibliography.23
SIST EN 15195:2007
EN 15195:2007 (E) 3 Foreword This document (EN 15195:2007) 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 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 October 2007, and conflicting national standards shall be withdrawn at the latest by October 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. SIST EN 15195:2007
EN 15195:2007 (E) 4 Introduction This document is derived from joint standardization work in the Energy Institute and ASTM International. It is based on IP 498/06 [1] published by the Energy Institute and harmonized with equivalent IP [2] and ASTM [3] Standards. The described method is an alternative quantitative determination of the cetane number of middle distillate fuels intended for use in compression ignition engines. Correlation studies between this method and EN ISO 5165:1998 have been done and the results of this are incorporated in this European Standard. The basis of this method is the derived cetane number correlation equation as given in Clause 13. The ongoing validation of the equation is monitored and evaluated through the existing monthly American and European fuel exchange programs. The validation data will be reviewed by CEN/TC 19 with a frequency of at least every two years. As a result of the review, CEN/TC 19 may make the decision to, if necessary, modify the existing equation/correlation or develop a new one. As part of this review, the sample types will be examined, and if certain types are underrepresented, further steps may be taken to evaluate how they perform. For the moment the basics of one type of apparatus are described1. Once more correlation data on different types of derived cetane number testing equipment is available, CEN/TC 19 will consider revising this European Standard.
1 The injection pump in the currently described apparatus is covered by a patent. SIST EN 15195:2007
EN 15195:2007 (E) 5 1 Scope This document specifies a test method for the quantitative determination of ignition delay of middle distillate fuels intended for use in compression ignition engines. The method utilizes a constant volume combustion chamber designed for operation by compression ignition, and employing direct injection of fuel into compressed air that is controlled to a specified pressure and temperature. An equation is given to calculate the derived cetane number (DCN) from the ignition delay measurement.
This standard is applicable to diesel fuels, including those containing FAME. The method is also applicable to middle distillate fuels of non-petroleum origin. However, users applying this standard especially to unconventional diesel fuels are warned that the relationship between derived cetane number and combustion behaviour in real engines is not yet fully understood. The standard covers the ignition delay range from 3,3 ms to 6,4 ms (61 DCN to 34 DCN). The combustion analyser can measure shorter or longer ignition delays, but precision can be affected. NOTE For the purpose of this European Standard, the expression “% (V/V)” is used to represent the volume fraction and “% (m/m)” the mass fraction. WARNING — The use of this standard may 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 establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2 Normative references 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. EN ISO 3170, Petroleum liquids — Manual sampling (ISO 3170:2004) EN ISO 3171, Petroleum liquids — Automatic pipeline sampling (ISO 3171:1988) EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987) EN ISO 5165:1998, Petroleum products - Determination of the ignition quality of diesel fuels - Cetane engine method (ISO 5165:1998) ISO 1998-2:1998, Petroleum industry – Terminology - Part 2: Properties and tests ISO 4010, Diesel engines — Calibrating nozzle, delay pintle type 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 1998-2:1998 and the following apply. 3.1 cetane number CN measure of the ignition performance of a fuel in a standardized engine test on a scale defined by reference fuels NOTE 1 It is expressed as the percentage by volume of hexadecane (cetane) in a reference blend having the same ignition delay as the fuel for analysis. The higher the cetane number, the shorter the ignition delay. SIST EN 15195:2007
EN 15195:2007 (E) 6 NOTE 2 ISO 1998-2 expresses it as "number on a conventional scale, indicating the ignition quality of a diesel fuel under standardized conditions", but for this document the definition as given is chosen. 3.2 ignition delay ID period of time, in milliseconds, between the start of fuel injection and the start of combustion NOTE In the context of this standard, this period is determined by movement and pressure sensors in the instrument.
3.3 derived cetane number DCN calculated value using an equation that correlates a combustion analyser ignition delay result to the cetane number 3.4 accepted reference value ARV value agreed upon as a reference for comparison NOTE The value may be that derived from scientific principles assigned by an accredited organization, or a consensus value based on collaborative experimental work under the auspices of a scientific or engineering group.
3.5 quality control sample stable and homogenous material(s) similar in nature to the materials under test, properly stored to ensure integrity, and available in sufficient quantity for repeated long-term testing 3.6 calibration reference fluid stable and homogenous fluid used to calibrate the performance of the combustion analyzer 3.7 verification reference fluid stable and homogenous fluid used to verify the performance of the combustion analyzer 4 Symbols and abbreviations Ti
injector coolant temperature Timin
minimum injector coolant temperature Timax maximum injector coolant temperature Tamin minimum combustion chamber air temperature Tamax maximum combustion chamber air temperature Tpsmin minimum combustion chamber pressure sensor temperature Tpsmax maximum combustion chamber pressure sensor temperature SIST EN 15195:2007
EN 15195:2007 (E) 7 5 Principle A test portion of the material under test is injected into a charge of compressed air in a constant volume combustion chamber. Sensors detect the start of injection and the start of combustion for each single-shot cycle. A complete test sequence consists of 15 preliminary combustion cycles to ensure apparatus equilibrium and 32 subsequent test cycles to obtain ignition delay values. The average ignition delay (ID) of these 32 cycles is inserted into an equation to obtain the derived cetane number (DCN). The DCN obtained by this procedure is an estimate of the cetane number (CN) obtained from the conventional large-scale engine test EN ISO 5165. 6 Reagents and materials 6.1 Water, unless otherwise specified, meeting the requirements for grade 3 of EN ISO 3696. 6.2 Coolant system fluid, 50:50 volumetric mixture of commercial grade ethylene glycol-type radiator antifreeze with water (6.1). NOTE This mixture meets the boiling point requirements and gives adequate protection of the coolant system against corrosion and mineral scale that can alter heat transfer and rating results. See the manufacturer’s manual for the correct ethylene glycol-type antifreeze quality.
6.3 Calibration reference fluid, heptane of a purity of minimum 99,5 % (m/m) to be used as the designated 3,78 ms ignition delay accepted reference value material. NOTE If the initial purity is not known and during a long-time stored reference fluid, it is advised to check the purity in accordance with IP 537 [4]. 6.4 Verification reference fluid, methylcyclohexane of a purity of minimum 99,0 % (m/m) to be used as the designated 10,4 ms ignition delay accepted reference value material. NOTE If the initial purity is not known and during a long-time stored reference fluid, it is advised to check the purity in accordance with IP 537 [4]. 6.5 Quality control sample 6.6 Combustion charge air, of oxygen content 20,9 % (V/V) ± 1,0 % (V/V), and containing less than 0,003 % (V/V) hydro-carbons and less than 0,025 % (V/V) water.
NOTE The effects of air quality deviations are still under investigation. The limiting values are based on current practice. 6.7 Actuating air, oil-free compressed air containing less than 0,1 % (V/V) water supplied at a minimum sustained pressure of 1,5 MPa. 6.8 Compressed nitrogen, of minimum purity 99,9 % (V/V). SIST EN 15195:2007
EN 15195:2007 (E) 8 7 Apparatus 7.1 Combustion analyzer 7.1.1 General The apparatus is described in more detail in Annex A. For the installation and set-up procedures, and for detailed system description, refer to the manufacturer’s manual. The standard system consists of a heated combustion chamber (see 7.1.2) with fluid cooling of designated areas, external chamber inlet and exhaust valves and associated piping, a pneumatically-driven fuel injection pump, a constant pressure fuel delivery system, a re-circulating coolant system, solenoids, sensors, controls and connection fittings for the compressed gas utilities. Figure 1 gives a schematic outline of the analyzer. 7.1.2 Combustion chamber, steel combustion chamber of capacity 0,213 l ± 0,002 l, further detailed in Annex A. 7.2 Filter medium, with a nominal pore size 3 µm to 5 µm, made of glass fibre, polytetrafluorethylene (PTFE) or nylon, of a size appropriate to the apparatus being used for sample filtration (see 8.4). SIST EN 15195:2007
EN 15195:2007 (E) 9
Key P1: combustion chamber pressure T4: combustion chamber air temperature (Ta), also charge air temperature P2: combustion chamber air pressure, also charge air pressure T5: (used for diagnostic functions) P3: injection actuator air pressure T6: injector (nozzle) coolant temperature (Ti) P4: inlet/exhaust valve actuator air pressure (gauge) T7: coolant return temperature P5: sample fuel reservoir pressure (gauge) N1: injector nozzle needle motion sensor T1: combustion chamber outer surface temperature C1: digital signal - fuel injection actuator T2: fuel injection pump temperature C2: digital signal - inlet valve actuator T3: combustion chamber pressure sensor temperature (Tps) C3: digital signal - exhaust valve actuator
: charge air line
: fuel injection pump driver air line
: inlet/exhaust valve actuator air line
: coolant system line
: fuel reservoir utility nitrogen line
: high pressure fuel line SIST EN 15195:2007
EN 15195:2007 (E) 10 Mechanical system 1. charge air supply 15. hydrocarbon waste 2. insulation 16. pump bleed 3. inlet valve 17. actuator utility compressed air supply 4. hydrocarbon waste 18. exhaust to ventilation system 5. nozzle bleed 19. drain 6. injector nozzle 20. liquid to air heat exchanger 7. fuel injection pump 21. air filter 8. fuel sample reservoir 22. fan 9. plunger 23. coolant reservoir 10. valved connector 24. chamber heating elements 11. fuel reservoir utility compressed nitrogen supply 25. exhaust valve 12. valved connector 26. combustion chamber pressure sensor coolant housing 13. pneumatic driver air surge tank 27. combustion chamber 14. pump heating elements 28. injector nozzle needle extension pin Figure 1 — Schematic overview of combustion analyser 8 Sampling 8.1 Unless otherwise specified, obtain samples in accordance with the procedures given in EN ISO 3170 or EN ISO 3171. 8.2 Collect and store samples in an opaque container to minimize exposure to UV emissions that can induce chemical reactions, which may affect ignition delay measurements. If the sample is not to be analyzed within 24 h, retain in a dark, cool/cold environment, and preferably under an inert gas. NOTE 1 Exposure of petroleum fuels to UV wavelengths of less than 550 nm for even a short period of time has been shown to affect ignition delay [5]. NOTE 2 The formation of peroxides and radicals, which affect the ignition delay, is minimized when the sample is stored in the dark, under a nitrogen blanket and in a cold (below 10 °C) environment.
8.3 Bring the laboratory sample to 18 °C to 32 °C before testing. 8.4 Filter the laboratory sample through the filter medium (see 7.2) at ambient temperature, without vacuum. Use a folding filter or syringe filter set-up. Immediately collect the filtered sample in an opaque container. WARNING — A glass syringe can split or shatter, potentially causing injury, if excessive force is applied to the plunger or if the glass is flawed. 9 Apparatus assembly and installation Annexes A and B give more details on the apparatus assembly and installation. The apparatus requires placement on a level floor with facilities for the hook-up of all utilities and engineering and technical support. The user shall ensure compliance with all local and national codes. The apparatus requires an environment with a temperature of 18 °C to 32 °C. The exhaust gases shall be directed into a low suction pressure fume extraction system. NOTE The heat exchange of the coolant system and the injection pump operate satisfactorily at 18 °C to 32 °C. CAUTION 1 — The apparatus requires high-pressure compressed air at high flow for intermittent short periods of time. SIST EN 15195:2007
EN 15195:2007 (E) 11 CAUTION 2 — The noise level without a noise reduction system is approximately 86 dB, measured at 1,5 m distance, and approximately 77 dB with noise reduction. Local regulations may apply to high noise levels, but ear protectors should be worn when equipment is in operation. 10 Preparation of apparatus 10.1 System start-up and warm-up 10.1.1 For more details refer to the manufacturer’s manual. 10.1.2 Switch on power to the combustion analyzer and the coolant pump. 10.1.3 Warm up the system. 10.1.4 Pressure the nitrogen and actuating air to the pressures given in the manufacturer’s manual. 10.1.5 Check the coolant temperature. Follow diagnostic procedures given in the manufacturer’s manual when the specified temperatures and tolerances are not met. 10.2 Standard operating conditions 10.2.1 Set the fuel injection pump temperature to 35 °C ± 3 °C. 10.2.2 Set the combustion charge air pressure to 2,137 MPa ± 0,007 MPa. 10.2.3 Check the sealing of the combustion chamber by measuring the pressure drop during a charge test in accordance with the manufacturer’s manual. Follow the diagnostic procedures given in the manual when the pressure drop is higher than specified. NOTE A high-pressure drop indicates unsatisfactory sealing of the combustion chamber.
10.3 Standard test conditions NOTE Standard test conditions are reached after 15 (preliminary) combustion cycles. Only the test conditions during the next 32 (measurement) combustion cycles are recorded and considered. 10.3.1 Run a sample in accordance with Clause 12. 10.3.2 Ensure that the difference between the minimum and maximum temperatures recorded during the 32 measurement combustion cycles for the injection coolant, Timin and Timax, are within the range given in Table 1. If the temperature is outside these limits at any time during the measurement, adjust the temperature in accordance with the instructions given in the manufacturer’s manual and repeat 10.3.1. NOTE Ti, Tamin, Tamax, Tpsmin and Tpsmax are printed out as a supplemental output result. Ti is also shown on the computer display during the test run. 10.3.3 Ensure that the difference between the minimum and maximum temperatures recorded during the 32 measurement combustion cycles for the combustion chamber air, Tamin and Tamax, are within the range given in Table 1. NOTE The combustion chamber air temperature is initially set by factory calibration and subsequently tuned by user calibration of the apparatus performance characteristics. The combustion chamber air temperature typically ranges from 515 °C to 565 °C. SIST EN 15195:2007
EN 15195:2007 (E) 12 10.3.4 Ensure that the difference between the minimum and maximum temperatures recorded during the 32 measurement combustion cycles for the combustion chamber pressure sensor, Tpsmin and Tpsmax, are within the range given in Table 1. NOTE Typical combustion chamber pressure sensor temperatures for the design described in this standard are in the range of 120 °C to 160 °C.
Table 1 —Typical standard test conditions Position Temperature range °C Injector coolant (Ti) 50 ± 4 Combustion chamber air Tamax - Tamin <2,5 Combustion chamber pressure sensor Tpsmax - Tpsmin <8
10.4 Final check If all the conditions described in 10.1 to 10.3 are met, the combustion analyzer is ready for measurement and/or calibration and verification. When one or more conditions are not met, follow the diagnostic procedures in the manufacturer’s manual to identify, and then remedy the problem. 11 Calibration, verification and quality control 11.1 General Calibrate and verify the apparatus at regular intervals not exceeding one month, and at any time that the verification or quality control checks are outside the tolerance limits given in Table 2. NOTE For further maintenance advice see Annex C. Table 2 — Tolerance limits for apparatus calibration and verification Fluid Test mode Tolerance limits ms Calibration (heptane) Single 3,78 ± 0,06 Calibration (heptane) Average of three 3,78 ± 0,01 Verification (MCH) Single 10,4 ± 0,6 Verification (MCH) Average of two 10,4 ± 0,5
11.2 Calibration 11.2.1 Clean the sensing surface of the combustion chamber pressure sensor and the entire pressure sensor housing in accordance with the manufacturer’s manual. 11.2.2 Measure the ignition delay of the calibration reference fluid (see 6.3) three times following the procedure given in Clause 12. 11.2.3 Check the three single test results and the average of the three results against the tolerances given in Table 2. If the tolerances are met, the apparatus is calibrated and fit to proceed to verification. SIST EN 15195:2007
EN 15195:2007 (E) 13 11.2.4 If the values in 11.2.3 deviate by more than the tolerance limits given in Table 2, the apparatus is not acceptable for use, and adjustment of the combustion chamber air temperature is required. Re-set the combustion chamber skin temperature to adjust the air temperature, allow a stabilization time of at least 10 min, and repeat 11.2.2. NOTE The ignition delay increases as combustion chamber air temperature decreases and conversely decreases as combustion air temperature increases. 11.3 Apparatus verification
11.3.1 Measure the ignition delay of the verification reference fluid (see 6.4) twice following the procedure given in Clause 12.
11.3.2 If the two single results and the average of the two results are within the tolerances given in Table 2, the calibration is verified and the apparatus is acceptable for use.
11.3.3 If the values in 11.3.2 deviate by more than the tolerance limits given in Table 2, a malfunction of the system is indicated, and the apparatus is not acceptable for use. Follow the diagnostic procedures in the manufacturer’s manual to identify and remedy the problem.
11.4 Quality control (QC) 11.4.1 Proper quality control procedures shall be in place to ensure continuous satisfactory operation of the analyzer. Quality control samples (see 6.5) shall be tested at intervals and records kept of the results. 11.4.2 Carry out quality control measurements on one or more quality control samples at least daily after apparatus preparation, and after every adjustment or replacement of consumables such as gases. NOTE 1 In continuous use, the recommended QC interval is at least every 10 samples. NOTE 2 The oxygen content of combustion charge compressed air may vary between batches (cylinders). Significant variation will lead to changes in ignition delay (higher oxygen content leads to lower ignition delay). 11.4.3 When quality control results are outside the control limits, carry out corrective action starting with a repeat of the calibration and verification procedures. 12 Test procedure 12.1 Check that the standard operating conditions given in 10.2 are in compliance.
12.2 Flush the fuel injection system with the filtered sample (see B.1). 12.3 Fill and purge the fuel injection system with filtered sample (see B.2). 12.4 Start the test sequence (see B.3). 12.5 Check that during the test all conditions are within the required limits given in 10.2 and Table 1. If the conditions are in compliance, proceed to 12.6. If one or more conditions are not within the stated limits, follow the diagnostic procedures in the manufacturer’s manual to identify and remedy the source of variability, and discard the test result. 12.6 Record the average ignition delay, ID, in milliseconds, to the nearest 0,001 ms. 12.7 Clean the fuel injection system (see B.4). SIST EN 15195:2007
EN 15195:2007 (E) 14 13 Calculation Calculate the derived cetane number, DCN, from the average ignition delay, ID, in milliseconds (recorded as in 1
...
SLOVENSKI oSIST prEN 15195:2005
PREDSTANDARD
maj 2005
Liquid petroleum products - Determination of ignition delay and derived cetane
number (DCN) of middle distillate fuels by combustion in a constant volume chamber
ICS 75.160.20 Referenčna številka
oSIST prEN 15195:2005(en)
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
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EUROPEAN STANDARD
DRAFT
prEN 15195
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2005
ICS
English version
Liquid petroleum products - Determination of ignition delay and
derived cetane number (DCN) of middle distillate fuels by
combustion in a constant volume chamber
Produits pétroliers liquides - Détermination du délai Flüssige Mineralöl-Erzeugnisse - Bestimmung des
d'inflammation et de l'indice de cétane dérivé (ICD) des Zündverzugs und der abgeleiteten Cetanzahl (ACZ) von
distillats moyens par combustion dans une enceinte à Kraftstoffen aus Mitteldestillaten in einer
volume constant Verbrennungskammer mit konstantem Volumen
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 Management Centre 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.
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
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15195:2005: E
worldwide for CEN national Members.
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prEN 15195:2005 (E)
Contents Page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Symbols and abbreviations .6
5 Principle.7
6 Reagents and materials .7
7 Apparatus .7
8 Sampling.8
9 Apparatus assembly and installation .9
10 Preparation of apparatus .9
11 Calibration, verification and quality control .10
12 Test procedure.12
13 Calculation.12
14 Expression of results .12
15 Precision.12
16 Test report .13
Annex A (normative) Test apparatus description .14
A.1 General.14
A.2 Apparatus description and assembly.14
A.3 Utilities .15
A.4 Control and data acquisition .16
A.5 Auxiliary apparatus.16
Annex B (normative) Operational details in support to the standard test procedure .17
B.1 Fuel injection system flushing .17
B.2 Fuel injection system filling and purging.17
B.3 Test sequence.17
B.4 Fuel injection system cleaning.19
Annex C (informative) Apparatus maintenance .20
C.1 General.20
C.2 Daily maintenance .20
C.3 Weekly maintenance .20
C.4 Yearly maintenance .20
Bibliography .21
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prEN 15195:2005 (E)
Foreword
This document (prEN 15195:2005) has been prepared by Technical Committee CEN/TC 19 “Petroleum
products, lubricants and related products”, the secretariat of which is held by NEN.
This document is currently submitted to the CEN Enquiry.
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prEN 15195:2005 (E)
Introduction
This document is derived from joint standardization work in the Energy Institute and ASTM International. It is
based on IP 498/05 published by the Energy Institute.
The described method is an alternative quantitative determination of ignition delay and derived cetane number
of middle distillate fuels intended for use in compression ignition engines. Correlation studies between this
method and EN ISO 5165:1998 has been done and results of this are incorporated in this European Standard.
1
For the moment the basics of one type of apparatus are described . Once more correlation data on different
types of derived cetane number testing equipment is available, CEN/TC 19 will consider revising this
European Standard.
1
The injection pump in the currently described apparatus is covered by a patent.
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prEN 15195:2005 (E)
1 Scope
This document specifies a method of test for the quantitative determination of ignition delay of middle distillate
fuels intended for use in compression ignition engines. The method utilizes a constant volume combustion
chamber designed for operation by compression ignition, and employing direct injection of fuel into
compressed air that is controlled to a specified pressure and temperature. An equation is given to calculate
the derived cetane number (DCN) from the ignition delay measurement.
This standard is applicable to fuels from petroleum and non-petroleum origin, although users are warned that
the relationship between ignition characteristics and engine performance in unconventional fuels is not yet
fully understood. The test is applicable over the range of 3,3 ms to 6,4 ms ignition delay.
NOTE 1 Ignition delay values of 3,3 ms to 6,4 ms correspond to derived cetane numbers (DCN) of 61 to 34
respectively.
NOTE 2 For the purpose of this European Standard, the expression “% (V/V)” is used to represent the volume fraction
and “% (m/m)” mass fraction
WARNING — The use of this standard may 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 establish appropriate safety and health practices and
determine the applicability of regulatory limitations prior to use.
2 Normative references
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.
EN ISO 3170, Petroleum liquids — Manual sampling (ISO 3170:2004)
EN ISO 3171, Petroleum liquids — Automatic pipeline sampling (ISO 3171:1988)
EN ISO 5165, Diesel fuels — Determination of the ignition quality — Cetane method (ISO 5165:1998)
ISO 3696, Water for analytical laboratory use — Specifications and test methods
ISO 4010, Diesel engines — Calibrating nozzle, delay pintle type
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1
cetane number
CN
measure of the ignition performance of a fuel in a standardized engine test on a scale defined by reference
fuels
NOTE Hexadecane (cetane), heptamethylnonane (HMN) and volumetrically proportioned mixtures of these materials
define the cetane number (CN) scale by the relationship: CN = cetane (%V/V) + 0,15 HMN (%V/V).
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3.2
ignition delay
ID
that period of time, in ms, between the start of fuel injection and the start of combustion
NOTE In the context of this standard, this period is determined by movement and pressure sensors in the instrument.
3.3
derived cetane number
DCN
calculated value, derived from the ignition delay in combustion of the tested fuel kept in a constant volume
chamber, giving a reasonably close approximation of the cetane number
3.4
primary reference fuels
hexadecane (cetane) (100) and heptamethyl-nonane (HMN) (15) and volumetrically proportioned mixtures of
these
NOTE derived from EN ISO 5165
3.5
accepted reference value
ARV
value agreed upon as a reference for comparison
NOTE The value may be that derived from scientific principles, that assigned by an accredited organization, or a
consensus value based on collaborative experimental work under the auspices of a scientific or engineering group.
3.6
quality control sample
stable and homogenous material(s) similar in nature to the materials under test, properly stored to ensure
integrity, and available in sufficient quantity for repeated long-term testing
3.7
calibration reference fluid
stable and homogenous fluid used to calibrate the performance of the combustion analyzer.
3.8
verification reference fluid
stable and homogenous fluid used to verify the performance of the combustion analyzer.
4 Symbols and abbreviations
T injector coolant temperature
i
Ti minimum injector coolant temperature
min
Ti maximum injector coolant temperature
max
Ta minimum combustion chamber air temperature
min
Ta maximum combustion chamber air temperature
max
Tps minimum combustion chamber pressure sensor temperature
min
Tps maximum combustion chamber pressure sensor temperature
max
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5 Principle
A test portion of the material under test is injected into a charge of compressed air in a constant volume
combustion chamber. Sensors detect the start of injection and the start of combustion for each single-shot
cycle. A complete test sequence consists of 15 preliminary combustion cycles to ensure apparatus equilibrium
and 32 subsequent test cycles to obtain ignition delay values. The average ignition delay (ID) of these 32
cycles is inserted into an equation to obtain the derived cetane number (DCN). The DCN obtained by this
procedure is an estimate of the cetane number (CN) obtained from the conventional large scale engine test
EN ISO 5165.
6 Reagents and materials
6.1 Water, unless otherwise specified, meeting the requirements for grade 3 of ISO 3696.
6.2 Coolant system fluid, 50:50 volumetric mixture of commercial grade ethylene glycol-type radiator
antifreeze with water (6.1).
NOTE This mixture meets the boiling point requirements and gives adequate protection of the coolant system against
corrosion and mineral scale that can alter heat transfer and rating results. See the manufacturer’s manual for the correct
ethylene glycol-type antifreeze quality.
6.3 Calibration reference fluid, heptane of a purity of minimum 99,5 % (m/m) to be used as the
designated 3,78 ms ignition delay accepted reference value material
NOTE If the initial purity is not known and during a long-time stored reference fluid, it is advised to check the purity in
accordance with IP PM-CY/04 [1].
6.4 Verification reference fluid, methylcyclohexane of a purity of minimum 99,0 % (m/m) to be used as
the designated 10,4 ms ignition delay accepted reference value material
NOTE If the initial purity is not known and during a long-time stored reference fluid, it is advised to check the purity in
accordance with IP PM-CY/04 [1].
6.5 Quality control sample
6.6 Combustion charge air, of oxygen content 20,9 % (V/V) ± 1,0 % (V/V), and containing less than
0,003 % (V/V) hydro-carbons and less than 0,025 % (V/V) water.
NOTE The effects of air quality deviations are still under investigation. The limiting values are based on current
practice.
6.7 Actuating air, oil free compressed air containing less than 0,1 % (V/V) water supplied at a minimum
sustained pressure of 1,5 MPa.
6.8 Compressed nitrogen, of minimum purity 99,9 % (V/V).
7 Apparatus
7.1 Combustion analyzer
The apparatus is described in more detail in Annex A. For the installation and set-up procedures, and for
detailed system description, refer to the manufacturer’s manual.
The standard system consists of a heated combustion chamber (7.1.1) with fluid cooling of designated areas,
external chamber inlet and exhaust valves and associated piping, a pneumatically-driven fuel injection pump,
a constant pressure fuel delivery system, a recirculating coolant system, solenoids, sensors, controls and
connection fittings for the compressed gas utilities. Figure 1 gives a schematic outline of the analyzer.
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7.1.1 Combustion chamber, steel combustion chamber of capacity 0,213 l ± 0,002 l, further detailed in
Annex A.
7.2 Filter medium, with a nominal pore size 3 µm to 5 µm, made of glass fibre, polytetrafluorethylene
(PTFE) or nylon, of a size appropriate to the apparatus being used for sample filtration (see 8.4).
Figure 1 — Schematic overview of combustion analyser
8 Sampling
8.1 Unless otherwise specified, obtain samples in accordance with the procedures given in EN ISO 3170 or
EN ISO 3171.
8.2 Collect and store samples in an opaque container to minimize exposure to UV emissions which can
induce chemical reactions which may affect ignition delay measurements. If the sample is not to be analyzed
within 24 h, retain in a dark, cool/cold environment, and preferably under an inert gas.
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NOTE 1 Exposure of petroleum fuels to UV wavelengths of less than 550 nm for even a short period of time has been
shown to affect ignition delay [2].
NOTE 2 The formation of peroxides and radicals, which affect the ignition delay, is minimized when the sample is
stored in the dark, under a nitrogen blanket and in a cold (below 10 °C) environment.
8.3 Bring the laboratory sample to 18 °C to 32 °C before testing.
8.4 Filter the laboratory sample through the filter medium (7.2) at ambient temperature, without vacuum.
Use a folding filter or syringe filter set-up. Immediately collect the filtered sample in an opaque container.
9 Apparatus assembly and installation
Annexes A and B give more details on the apparatus assembly and installation. The apparatus requires
placement on a level floor with facilities for the hook-up of all utilities and engineering and technical support.
The user shall ensure compliance with all local and national codes. The apparatus requires an environment
with a temperature of 18 °C to 32 °C. The exhaust gases shall be directed into a low suction pressure fume
extraction system.
NOTE The heat exchange of the coolant system and the injection pump operate satisfactorily at 18 °C to 32 °C.
CAUTION 1 — The apparatus requires high-pressure compressed air at high flow for intermittent short
periods of time.
CAUTION 2 — The noise level without a noise reduction system is approximately 86 dB, measured at
1,5 m distance, and approximately 77 dB with noise reduction. Local regulations may apply to high
noise levels, but ear protectors should be worn when equipment is in operation.
10 Preparation of apparatus
10.1 System start-up and warm-up
10.1.1 For more details, refer to the manufacturer’s manual.
10.1.2 Switch on power to the combustion analyzer and the coolant pump.
10.1.3 Warm up the system.
10.1.4 Pressure the nitrogen and actuating air to the pressures given in the manufacturer’s manual.
10.1.5 Check the coolant temperature. Follow diagnostic procedures given in the manufacturer’s manual
when the specified temperatures and tolerances are not met.
10.2 Standard operating conditions
10.2.1 Set the fuel injection pump temperature to 35 °C ± 3 °C.
10.2.2 Set the combustion charge air pressure to 2,137 MPa ± 0,007 MPa.
10.2.3 Check the sealing of the combustion chamber by measuring the pressure drop during a charge test
in accordance with the manufacturer’s manual. Follow the diagnostic procedures given in the manual when
the pressure drop is higher than specified.
NOTE A high pressure drop indicates unsatisfactory sealing of the combustion chamber.
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10.3 Standard test conditions
NOTE Standard test conditions are reached after 15 (preliminary) combustion cycles. Only the test conditions during
the next 32 (measurement) combustion cycles are recorded and considered.
10.3.1 Run a sample in accordance with Clause 12.
10.3.2 Ensure that the difference between the minimum and maximum temperatures recorded during the 32
measurement combustion cycles for the injection coolant, Ti and Ti are within the range given in Table 1.
min max,
If the temperature is outside these limits at any time during the measurement, adjust the temperature i
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