1、Designation: D6890 11Standard 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.1. Scope*1.1 This automated laboratory test method covers the quan-ti
3、tative 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 applicable to productstypical of ASTM Specification D975 grades No. 1-D and 2
4、-Dregular and low-sulfur diesel fuel oils, European standardEN 590, 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 fuelblending components.1.2 This test method measures the ignition de
5、lay 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 number (DCN).1.3 This test method covers the ignition delay range fro
6、m3.1 to 6.5 ms (64 to 33 DCN). The combustion analyzer canmeasure shorter and longer ignition delays, but precision maybe affected. For these shorter or longer ignition delays thecorrelation equation for DCN is given in Appendix X2. Thereis no information about how DCNs outside the 33 to 64 rangecom
7、pare 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 thesafety concerns, if any, associated with its use. It is theresponsibility of the
8、 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 Number of Diesel Fuel OilD975 Specification for Diesel Fuel OilsD1193 Specificat
9、ion for Reagent WaterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD5854 Practice for Mixing and Handling of Liquid Samplesof Petro
10、leum and Petroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6708 Practic
11、e for StatisticalAssessment 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 Diesel EnginesCalibrating Nozzle, DelayPintle TypeISO 4259 Petroleum products
12、Determination and applica-tion of precision data in relation to methods of test2.3 EN Standard:EN 590 Automotive FuelsDieselRequirements andTest Methods52.4 Energy Institute Standard:1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the dire
13、ct responsibility of SubcommitteeD02.01 on Combustion Characteristics.Current edition approved April 1, 2011. Published April 2011. Originallyapproved in 2003. Last previous edition approved in 2010 as D689010a. DOI:10.1520/D6890-11.2This test method is based on IP PM CQ/2001, published in the IP St
14、andardMethods 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, orc
15、ontact 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, 25W. 43rd St., 4th floor,New York, NY 10036.5Available from European Committee f
16、or Standardization. Central Secretariat:rue de Stassart, 36, B-1050 Brussels, Belgium.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.IP 41 Ignition Quality of Diesel
17、FuelsCetane Engine TestMethod62.5 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 compariso
18、n and that is derivedas (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 col
19、laborative experimental workunder 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 collabora
20、tive experimental work.3.1.2 cetane number (CN), na measure of the ignitionperformance of a diesel fuel oil obtained by comparing it toreference fuels in a standardized engine test. D41753.1.2.1 DiscussionIn the context of this test method,cetane number is that defined by Test Method D613/IP 41.3.1.
21、3 check standard, nin QC testing, material having anaccepted reference value used to determine the accuracy of ameasurement system. D62993.1.3.1 DiscussionIn the context of this test method,check standard refers to heptane.3.1.4 quality control (QC) sample, nfor use in qualityassurance programs to d
22、etermine 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 is
23、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 pressureintroduce
24、d 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 ceta
25、ne 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 of t
26、ime, 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 lift
27、 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 progress.3
28、.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 QCquality c
29、ontrol.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 using s
30、ensors 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 cetane
31、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.5.2 This test can be used by engine manufacturers, petro-leum refiners and marketers, and
32、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 may be applied to non-conventional fuels. It isr
33、ecognized 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 engines for these types of fuels.5.5 This test dete
34、rmines 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 check standard to sunlight or6Available from Instit
35、ute of Petroleum, 61 New Cavendish St., London, W1G7AR, U.K.7Available from the Canadian General Standards Board, Gatineau, Canada, K1A1G6.D6890 112fluorescent lamp UV emissions to minimize induced chemicalreactions that can affect ignition delay measurements.86.1.1 Exposure of these fuels and mater
36、ials to UV wave-lengths shorter than 550 nanometers for a short period of timemay significantly affect ignition delay measurements.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 c
37、old room at a temperature of less than10C, and covered by a blanket of nitrogen.6.2 Statistical analysis of data from a sequential testingstudy (Note 2) revealed a possible carryover effect in succeed-ing tests on samples containing 2ethylhexylnitrate cetaneimprover at concentrations above 2000 ppm.
38、NOTE 2In the sequential testing study, a fuel without cetane improverwas tested three times back-to-back. Then a fuel with 2ethylhexylnitratecetane improver at concentrations above 2000 ppm was tested. Subse-quently, the same fuel without cetane improver was tested three times.Statistical analyses o
39、f repeat data on two units were examined forevidence of hysteresis.7. Apparatus7.1 GeneralThis test method uses an integrated auto-mated analytical measurement system9comprised of: (1)aconstant volume compression ignition combustion chamberwith external electrical heating elements, suitable insulati
40、onand pneumatically actuated intake and exhaust valves, (2)aheated, pneumatically actuated fuel injection system10withpump, injector nozzle assembly, and associated sample reser-voir, (3) a coolant system with a liquid-to-air heat exchanger,filter, circulating pump and flow control valves, (4) tempe
41、ra-ture thermocouples, pressure gages and sensors, an injectornozzle needle motion sensor, compressed gas pressure regula-tors, control valves, pneumatic actuator components, andsolenoid valves, and (5) a computer to control test sequencing,acquire and accumulate sensor signal data, provide processi
42、ngcalculations, and automatically output a printed report of someimportant test parameters (see Fig. 1).7.2 See Annex A2, Combustion 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 c
43、apableof controlling the downstream pressure to a minimum pressureof 2.2 MPa.7.3.2 Actuator Utility Compressed Air Regulator, a two-stage regulator capable of controlling the downstream pressureto a minimum pressure of 1.3 MPa.7.3.3 Fuel Reservoir Utility Compressed Nitrogen Regula-tor, a single or
44、two-stage regulator capable of controlling thedownstream pressure to a minimum pressure of 350 kPa.7.4 Auxiliary Apparatus:7.4.1 Diesel Fuel Oil Sample Filter, a single-use glass fiber,polytetrafluorethylene (PTFE), or nylon filter with a nominalpore size of 3 to 5 micrometers (m) for use with a gla
45、sssyringe.7.4.2 Syringe, a glass syringe of a minimum volume of100 mL.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 is 3.78ms. (WarningFlammable. Vapor harmful. Vapor may causef
46、lash 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 meet Ignition De
47、layARV(typically 1 to 1.5milliseconds shorter). It is recommended that new material be qualifiedprior 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 is 3.78ms. (WarningFlammable. Vapor harmful. Vapor may causeflas
48、h 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.)8.4 Charge Air, compressed air containing 20.9 6 1.0volume percent oxygen, less than 0.003
49、 volume percenthydrocarbons, and less than 0.025 volume percent water. Forcharge air cylinders supplied with a blend of oxygen andnitrogen, it is required that a quality control test be performedafter an air cylinder has been changed. (WarningCompressed gas under high pressure that supports combus-tion.)8.5 Coolant System Fluid, a 50:50 volume mixture of waterand commercial ethylene glycol-based antifreeze. (WarningPoison. May be harmful or fatal if inhaled or swallowed.)8.5.1 Antifreeze, commercial automotive cooling systemethylene glycol-b
