1、Designation: D6890 13b1Standard Test Method forDetermination of Ignition Delay and Derived Cetane Number(DCN) of Diesel Fuel Oils by Combustion in a ConstantVolume Chamber1,2This standard is issued under the fixed designation D6890; the number immediately following the designation indicates the year
2、 oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorial changes to SI unit formatting were made in April 2014
3、.1. Scope*1.1 This automated laboratory test method covers the quan-titative determination of the ignition characteristics of conven-tional diesel fuel oil, oil-sands based fuels, blends of fuelcontaining biodiesel material, diesel fuel oils containing cetanenumber improver additives, and is applica
4、ble to productstypical of ASTM Specification D975 grades No. 1-D and 2-Dregular and low-sulfur diesel fuel oils, European standard EN590, and Canadian standards CAN/CGSB-3.517 and 3.6-2000.The test method may also be applied to the quantitativedetermination of the ignition characteristics of diesel
5、fuelblending components.1.2 This test method measures the ignition delay and utilizesa constant volume combustion chamber with direct fuel injec-tion into heated, compressed air. An equation correlates anignition delay determination to cetane number by Test MethodD613, resulting in a derived cetane
6、number (DCN).1.3 This test method covers the ignition delay range from3.1 ms to 6.5 ms (64 DCN to 33 DCN). The combustionanalyzer can measure shorter and longer ignition delays, butprecision may be affected. For these shorter or longer ignitiondelays the correlation equation for DCN is given in Appe
7、ndixX2. There is no information about how DCNs outside the 33 to64 range compare to Test Method D613 cetane numbers.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all of thesafe
8、ty concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D613 Test Method for Cetane Numb
9、er of Diesel Fuel OilD975 Specification for Diesel Fuel OilsD1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD4177 Practice for Automatic Sampling of Petroleum andPetrol
10、eum ProductsD5854 Practice for Mixing and Handling of Liquid Samplesof Petroleum and Petroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and BiasDa
11、ta for Use in Test Methods for Petroleum Products andLubricantsD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a MaterialE456 Terminology Relating to Quality and Statistics2.2 ISO Standards:4ISO 4010
12、Diesel EnginesCalibrating Nozzle, Delay PintleTypeISO 4259 Petroleum productsDetermination and applica-tion of precision data in relation to methods of test1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsib
13、ility ofSubcommittee D02.01 on Combustion Characteristics.Current edition approved Oct. 1, 2013. Published October 2013. Originallyapproved in 2003. Last previous edition approved in 2013 as D6890 13a. DOI:10.1520/D6890-13BE01.2This test method is based on IP PM CQ/2001, published in the IP Standard
14、Methods for Analysis and Testing of Petroleum and Related Products and BritishStandard 2000 Parts. Copyrighted by Energy Institute, 61 New Cavendish Street,London, W1G 7AR, UK. Adapted with permission of Energy Institute.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact
15、 ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available fromAmerican National Standards Institute, 25 W. 43rd St., 4th floor,New York, NY 10036.*A Summary of Changes section appears at
16、the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.3 EN Standard:EN 590 Automotive FuelsDieselRequirements and TestMethods52.4 Energy Institute Standard:IP 41 Ignition Quality of Diesel FuelsCetane Engine TestMe
17、thod62.5 Canadian Standards:CAN/CGSB-3.517-2000 Automotive Low Sulfur DieselFuelSpecification7CAN/CGSB 3.6-2000 Automotive Diesel FuelSpecification73. Terminology3.1 Definitions:3.1.1 accepted reference value (ARV), nvalue that servesas an agreed-upon reference for comparison and that is derivedas (
18、1) a theoretical or established value, based on scientificprinciples, (2) an assigned value, based on experimental workof some national or international organization, such as the U.S.National Institute of Standards and Technology (NIST), or (3)a consensus value, based on collaborative experimental w
19、orkunder the auspices of a scientific or engineering group. E4563.1.1.1 DiscussionIn the context of this test method,accepted reference value is understood to apply to the ignitiondelay of specific reference materials determined under repro-ducibility conditions by collaborative experimental work.3.
20、1.2 biodiesel, nfuel comprised of mono-alkyl esters oflong chain fatty acids derived from vegetable oils or animalfats, designated B100.3.1.3 biodiesel blend (BXX), nblend of biodiesel fuel withdiesel fuel oils.3.1.3.1 DiscussionIn the abbreviation, BXX, the XX rep-resents the volume percentage of b
21、iodiesel fuel in the blend.3.1.4 cetane number (CN), na measure of the ignitionperformance of a diesel fuel oil obtained by comparing it toreference fuels in a standardized engine test. D41753.1.4.1 DiscussionIn the context of this test method,cetane number is that defined by Test Method D613/IP 41.
22、3.1.5 check standard, nin QC testing, material having anaccepted reference value used to determine the accuracy of ameasurement system. D62993.1.5.1 DiscussionIn the context of this test method,check standard refers to heptane.3.1.6 quality control (QC) sample, nfor use in qualityassurance programs
23、to determine and monitor the precision andstability of a measurement system, a stable and homogeneousmaterial having physical or chemical properties, or both,similar to those of typical samples tested by the analyticalmeasurement system. The material is properly stored to ensuresample integrity, and
24、 is available in sufficient quantity forrepeated, long term testing. D62993.2 Definitions of Terms Specific to This Standard:3.2.1 calibration reference material, npure chemical hav-ing an assigned ignition delay accepted reference value.3.2.2 charge air, ncompressed air at a specified pressureintro
25、duced to the combustion chamber at the beginning of eachtest cycle.3.2.3 charge air temperature, ntemperature, in C, of theair inside the combustion chamber.3.2.4 combustion analyzer, nintegrated compression igni-tion apparatus to measure the ignition characteristics of dieselfuel oil.3.2.5 derived
26、cetane number (DCN), na number calcu-lated using a conversion equation to determine a cetanenumber.3.2.5.1 DiscussionThe conversion equation relates a mea-sured ignition delay or ignition delay and combustion delayfrom a combustion analyzer to a cetane number.3.2.6 ignition delay (ID), nthat period
27、of time, in milli-seconds (ms), between the start of fuel injection and the start ofcombustion as determined using the specific combustion ana-lyzer applicable for this test method.3.2.6.1 DiscussionIn the context of this test method, startof fuel injection is interpreted as the initial movement or
28、lift ofthe injector nozzle needle as measured by a motion sensor; startof combustion is interpreted as that point in the combustioncycle when a significant and sustained increase in rate-of-change in pressure, as measured by a pressure sensor in thecombustion chamber, ensures combustion is in progre
29、ss.3.2.7 operating period, nthe time, not to exceed 12 h,between successive calibration or QC testing, or both, of thecombustion analyzer by a single operator.3.3 Abbreviations:3.3.1 ARVaccepted reference value.3.3.2 CNcetane number.3.3.3 DCNderived cetane number.3.3.4 IDignition delay.3.3.5 QCquali
30、ty control.4. Summary of Test Method4.1 A small specimen of diesel fuel oil is injected into aheated, temperature-controlled constant volume chamber,which has previously been charged with compressed air. Eachinjection produces a single-shot, compression ignition combus-tion cycle. ID is measured usi
31、ng sensors that detect the start offuel injection and the start of significant combustion for eachcycle. A complete sequence comprises 15 preliminary cyclesand 32 further cycles. The ID measurements for the last 32cycles are averaged to produce the ID result. An equationconverts the ID result to DCN
32、 (derived cetane number), whichis correlated to cetane number by Test Method D613.5. Significance and Use5.1 The ID and DCN values determined by this test methodcan provide a measure of the ignition characteristics of dieselfuel oil in compression ignition engines.5Available from European Committee
33、for Standardization. Central Secretariat:rue de Stassart, 36, B-1050 Brussels, Belgium.6Available from Institute of Petroleum, 61 New Cavendish St., London, W1G7AR, U.K.7Available from the Canadian General Standards Board, Gatineau, Canada, K1A1G6.D6890 13b125.2 This test can be used by engine manuf
34、acturers, petro-leum refiners and marketers, and in commerce as a specifica-tion aid to relate or match fuels and engines.5.3 The relationship of diesel fuel oil DCN determinationsto the performance of full-scale, variable-speed, variable-loaddiesel engines is not completely understood.5.4 This test
35、 may be applied to non-conventional fuels. It isrecognized that the performance of non-conventional fuels infull-scale engines is not completely understood. The user istherefore cautioned to investigate the suitability of ignitioncharacteristic measurements for predicting performance infull-scale en
36、gines for these types of fuels.5.5 This test determines ignition characteristics and requiresa sample of approximately 100 mL and a test time ofapproximately 20 min on a fit-for-use instrument.6. Interferences6.1 Minimize exposure of sample fuels, calibration refer-ence materials, QC samples, and ch
37、eck standard to sunlight orfluorescent lamp UV emissions to minimize induced chemicalreactions that can affect ignition delay measurements.86.1.1 Exposure of these fuels and materials to UV wave-lengths shorter than 550 nanometers for a short period of timemay significantly affect ignition delay mea
38、surements.NOTE 1The formation of peroxide and radicals can effect ignitiondelay measurement. These formations are minimized when the sample ormaterial is stored in the dark in a cold room at a temperature of less than10C, and covered by a blanket of nitrogen.6.2 Statistical analysis of data from a s
39、equential testingstudy (Note 2) revealed a possible carryover effect in succeed-ing tests on samples containing 2ethylhexylnitrate cetaneimprover at concentrations above 2000 ppm.NOTE 2In the sequential testing study, a fuel without cetane improverwas tested three times back-to-back. Then a fuel wit
40、h 2ethylhexylnitratecetane improver at concentrations above 2000 ppm was tested.Subsequently, the same fuel without cetane improver was tested threetimes. Statistical analyses of repeat data on two units were examined forevidence of hysteresis.7. Apparatus7.1 GeneralThis test method uses an integrat
41、ed automatedanalytical measurement system9comprised of: (1) a constantvolume compression ignition combustion chamber with exter-nal electrical heating elements, suitable insulation and pneu-matically actuated intake and exhaust valves, (2) a heated,pneumatically actuated fuel injection system10with
42、pump,injector nozzle assembly, and associated sample reservoir, (3)a coolant system with a liquid-to-air heat exchanger, filter,circulating pump and flow control valves, (4) temperaturethermocouples, pressure gages and sensors, an injector nozzleneedle motion sensor, compressed gas pressure regulato
43、rs,control valves, pneumatic actuator components, and solenoidvalves, and (5) a computer to control test sequencing, acquireand accumulate sensor signal data, provide processingcalculations, and automatically output a printed report of someimportant test parameters (see Fig. 1).7.2 See Annex A2, Com
44、bustion Analyzer Equipment De-scription and Specifications, for detailed information.7.3 Compressed Gas Pressure Regulators:7.3.1 Charge Air Regulator, a two-stage regulator capable ofcontrolling the downstream pressure to a minimum pressure of2.2 MPa.7.3.2 Actuator Utility Compressed Air Regulator,
45、 a two-stage regulator capable of controlling the downstream pressureto a minimum pressure of 1.3 MPa.7.3.3 Fuel Reservoir Utility Compressed NitrogenRegulator, a single or two-stage regulator capable of control-ling the downstream pressure to a minimum pressure of350 kPa.7.4 Auxiliary Apparatus:7.4
46、.1 Diesel Fuel Oil Sample Filter, a single-use glass fiber,polytetrafluorethylene (PTFE), or nylon filter with a nominalpore size of 3 m to 5 m for use with a positive pressuredelivery device such as a glass syringe or glass-lined metalsyringe.7.4.2 Positive Pressure Delivery Device, a non-reactivep
47、ositive pressure delivery device such as a glass syringe or aglass-lined metal syringe.8. Reagents and Materials8.1 Calibration Reference Materials:8.1.1 Heptane (n-heptane), with a minimum purity of 99.5volume percent. The assigned IDARVfor this material is3.78 ms. (WarningFlammable. Vapor harmful.
48、 Vapor maycause flash fire.)8.1.2 Methylcyclohexane (MCH), with a minimum purity of99.0 volume percent. The assigned IDARVfor this material is10.4 ms. (WarningFlammable. Vapor harmful. Vapor maycause flash fire.)NOTE 3Experience has found some MCH meeting the purity speci-fication but which does not
49、 meet Ignition DelayARV(typically 1 millisec-ond to 1.5 milliseconds shorter). It is recommended that new material bequalified prior to use.8.2 Check Standard:8.2.1 Heptane (n-heptane), with a minimum purity of 99.5volume percent. The assigned IDARVfor this material is3.78 ms. (WarningFlammable. Vapor harmful. Vapor maycause flash fire.)8.3 Quality Control Sample, a stable and homogeneousdiesel fuel oil having physical and chemical properties similarto those of typical sample fuels routinely tested. (WarningCombustible. Vapor harmful.
