1、Designation: D6890 12aD6890 13Standard 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 t
2、he year 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
3、 quantitative determination of the ignition characteristics of conventionaldiesel fuel oil, oil-sands based fuels, blends of fuel containing biodiesel material, diesel fuel oils containing cetane numberimprover additives, and is applicable to products typical of ASTM Specification D975 grades No. 1-
4、D and 2-D regular andlow-sulfur diesel fuel oils, European standard EN 590, and Canadian standards CAN/CGSB-3.517 and 3.6-2000. The test methodmay also be applied to the quantitative determination of the ignition characteristics of diesel fuel blending components.1.2 This test method measures the ig
5、nition delay and utilizes a constant volume combustion chamber with direct fuel injectioninto heated, compressed air. An equation correlates an ignition delay determination to cetane number by Test Method D613,resulting in a derived cetane number (DCN).1.3 This test method covers the ignition delay
6、range from 3.1 to 6.5 ms (64 to 33 DCN). The combustion analyzer can measureshorter and longer ignition delays, but precision may be affected. For these shorter or longer ignition delays the correlation equationfor DCN is given in Appendix X2. There is no information about how DCNs outside the 33 to
7、 64 range compare to Test MethodD613 cetane numbers.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the respo
8、nsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D613 Test Method for Cetane Number of Diesel Fuel OilD975 Specification for Diesel Fuel OilsD119
9、3 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4175 Terminology Relating to Petroleum, Petroleum Products, and LubricantsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD5854 Practice for Mixing and Handling of Liquid
10、Samples of Petroleum and Petroleum ProductsD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System PerformanceD6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lu
11、bricantsD6708 Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purportto Measure the Same Property of a MaterialE456 Terminology Relating to Quality and Statistics1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Pr
12、oducts and Lubricants and is the direct responsibility of Subcommittee D02.01 onCombustion Characteristics.Current edition approved Nov. 1, 2012March 1, 2013. Published March 2013April 2013. Originally approved in 2003. Last previous edition approved in 2012 asD689012.12a. DOI: 10.1520/D6890-12A.10.
13、1520/D6890-13.2 This test method is based on IP PM CQ/2001, published in the IP Standard Methods for Analysis and Testing of Petroleum and Related Products and British Standard2000 Parts. Copyrighted by Energy Institute, 61 New Cavendish Street, London, W1G 7AR, UK. Adapted with permission of Energy
14、 Institute.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is inten
15、ded only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the curren
16、t versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12.2 ISO Standards:4ISO 4010 Diese
17、l EnginesCalibrating Nozzle, Delay Pintle TypeISO 4259 Petroleum productsDetermination and application of precision data in relation to methods of test2.3 EN Standard:EN 590 Automotive FuelsDieselRequirements and Test Methods52.4 Energy Institute Standard:IP 41 Ignition Quality of Diesel FuelsCetane
18、 Engine Test Method62.5 Canadian Standards:CAN/CGSB-3.517-2000 Automotive Low Sulfur Diesel FuelSpecification7CAN/CGSB 3.6-2000 Automotive Diesel FuelSpecification73. Terminology3.1 Definitions:3.1.1 accepted reference value (ARV), nvalue that serves as an agreed-upon reference for comparison and th
19、at is derived as(1) a theoretical or established value, based on scientific principles, (2) an assigned value, based on experimental work of somenational or international organization, such as the U.S. National Institute of Standards and Technology (NIST), or (3) a consensusvalue, based on collabora
20、tive experimental work under 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 ignition delay of specific referencematerials determined under reproducibility conditions by collaborative
21、experimental work.3.1.2 biodiesel, nfuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats,designated B100.3.1.3 biodiesel blend (BXX), nblend of biodiesel fuel with diesel fuel oils.3.1.3.1 DiscussionIn the abbreviation, BXX, the XX represents the v
22、olume percentage of biodiesel fuel in the blend.3.1.4 cetane number (CN), na measure of the ignition performance of a diesel fuel oil obtained by comparing it to referencefuels in a standardized engine test. D41753.1.4.1 DiscussionIn the context of this test method, cetane number is that defined by
23、Test Method D613/IP 41.3.1.5 check standard, nin QC testing, material having an accepted 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 q
24、uality assurance programs to determine and monitor the precision and stabilityof a measurement system, a stable and homogeneous material having physical or chemical properties, or both, similar to those oftypical samples tested by the analytical measurement system. The material is properly stored to
25、 ensure sample integrity, and isavailable in sufficient quantity for repeated, long term testing. D62993.2 Definitions of Terms Specific to This Standard:3.2.1 calibration reference material, npure chemical having an assigned ignition delay accepted reference value.3.2.2 charge air, ncompressed air
26、at a specified pressure introduced to the combustion chamber at the beginning of each testcycle.3.2.3 charge air temperature, ntemperature, in C, of the air inside the combustion chamber.4 Available from American National Standards Institute, 25 W. 43rd St., 4th floor, New York, NY 10036.5 Available
27、 from European Committee for Standardization. Central Secretariat: rue de Stassart, 36, B-1050 Brussels, Belgium.6 Available from Institute of Petroleum, 61 New Cavendish St., London, W1G 7AR, U.K.7 Available from the Canadian General Standards Board, Gatineau, Canada, K1A 1G6.D6890 1323.2.4 combust
28、ion analyzer, nintegrated compression ignition apparatus to measure the ignition characteristics of diesel fueloil.3.2.5 derived cetane number (DCN), na number calculated using a conversion equation to determine a cetane number.3.2.5.1 DiscussionThe conversion equation relates a measured ignition de
29、lay or ignition delay and combustion delay from a combustion analyzer toa cetane number.3.2.6 ignition delay (ID), nthat period of time, in milliseconds (ms), between the start of fuel injection and the start ofcombustion as determined using the specific combustion analyzer applicable for this test
30、method.3.2.6.1 DiscussionIn the context of this test method, start of fuel injection is interpreted as the initial movement or lift of the injector nozzle needleas measured by a motion sensor; start of combustion is interpreted as that point in the combustion cycle when a significant andsustained in
31、crease in rate-of-change in pressure, as measured by a pressure sensor in the combustion chamber, ensures combustionis in progress.3.2.7 operating period, nthe time, not to exceed 12 h, between successive calibration or QC testing, or both, of the combustionanalyzer by a single operator.3.3 Abbrevia
32、tions: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 control.4. Summary of Test Method4.1 A small specimen of diesel fuel oil is injected into a heated, temperature-controlled constant volume chamber, which haspreviously
33、been charged with compressed air. Each injection produces a single-shot, compression ignition combustion cycle. IDis measured using sensors that detect the start of fuel injection and the start of significant combustion for each cycle. A completesequence comprises 15 preliminary cycles and 32 furthe
34、r cycles. The ID measurements for the last 32 cycles are averaged toproduce the ID result. An equation converts the ID result to DCN (derived cetane number), which is correlated to cetane numberby Test Method D613.5. Significance and Use5.1 The ID and DCN values determined by this test method can pr
35、ovide a measure of the ignition characteristics of diesel fueloil in compression ignition engines.5.2 This test can be used by engine manufacturers, petroleum refiners and marketers, and in commerce as a specification aidto relate or match fuels and engines.5.3 The relationship of diesel fuel oil DC
36、N determinations to the performance of full-scale, variable-speed, variable-load dieselengines is not completely understood.5.4 This test may be applied to non-conventional fuels. It is recognized that the performance of non-conventional fuels infull-scale engines is not completely understood. The u
37、ser is therefore cautioned to investigate the suitability of ignitioncharacteristic measurements for predicting performance in full-scale engines for these types of fuels.5.5 This test determines ignition characteristics and requires a sample of approximately 100 mLand a test time of approximately20
38、 min on a fit-for-use instrument.6. Interferences6.1 Minimize exposure of sample fuels, calibration reference materials, QC samples, and check standard to sunlight orfluorescent lamp UV emissions to minimize induced chemical reactions that can affect ignition delay measurements.86.1.1 Exposure of th
39、ese fuels and materials to UV wavelengths shorter than 550 nanometers for a short period of time maysignificantly affect ignition delay measurements.8 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1502.D6890 133NOTE 1The f
40、ormation of peroxide and radicals can effect ignition delay measurement. These formations are minimized when the sample or materialis stored in the dark in a cold room at a temperature of less than 10C, and covered by a blanket of nitrogen.6.2 Statistical analysis of data from a sequential testing s
41、tudy (Note 2) revealed a possible carryover effect in succeeding testson samples containing 2ethylhexylnitrate cetane improver at concentrations above 2000 ppm.NOTE 2In the sequential testing study, a fuel without cetane improver was tested three times back-to-back.Then a fuel with 2ethylhexylnitrat
42、e cetaneimprover at concentrations above 2000 ppm was tested. Subsequently, the same fuel without cetane improver was tested three times. Statistical analysesof repeat data on two units were examined for evidence of hysteresis.7. Apparatus7.1 GeneralThis test method uses an integrated automated anal
43、ytical measurement system9 comprised of: (1) a constantvolume compression ignition combustion chamber with external electrical heating elements, suitable insulation and pneumaticallyactuated intake and exhaust valves, (2) a heated, pneumatically actuated fuel injection system10 with pump, injector n
44、ozzleassembly, and associated sample reservoir, (3) a coolant system with a liquid-to-air heat exchanger, filter, circulating pump andflow control valves, (4) temperature thermocouples, pressure gages and sensors, an injector nozzle needle motion sensor,compressed gas pressure regulators, control va
45、lves, pneumatic actuator components, and solenoid valves, and (5) a computer tocontrol test sequencing, acquire and accumulate sensor signal data, provide processing calculations, and automatically output aprinted report of some important test parameters (see Fig. 1).7.2 See Annex A2, Combustion Ana
46、lyzer Equipment Description and Specifications, for detailed information.7.3 Compressed Gas Pressure Regulators:7.3.1 Charge Air Regulator, a two-stage regulator capable of controlling the downstream pressure to a minimum pressure of 2.2MPa.7.3.2 Actuator Utility Compressed Air Regulator, a two-stag
47、e regulator capable of controlling the downstream pressure to aminimum pressure of 1.3 MPa.7.3.3 Fuel Reservoir Utility Compressed Nitrogen Regulator, a single or two-stage regulator capable of controlling thedownstream pressure to a minimum pressure of 350 kPa.7.4 Auxiliary Apparatus:7.4.1 Diesel F
48、uel Oil Sample Filter, a single-use glass fiber, polytetrafluorethylene (PTFE), or nylon filter with a nominal poresize of 3 to 5 micrometers (m) for use with a glass syringe.7.4.2 Syringe, a glass syringe of a minimum volume of 100 mL.100 mL.8. Reagents and Materials8.1 Calibration Reference Materi
49、als:8.1.1 Heptane (n-heptane), with a minimum purity of 99.5 volume percent. The assigned IDARV for this material is 3.78 ms.(WarningFlammable. Vapor harmful. Vapor may cause flash fire.)8.1.2 Methylcyclohexane (MCH), with a minimum purity of 99.0 volume percent. The assigned IDARV for this material is 10.4ms. (WarningFlammable. Vapor harmful. Vapor may cause flash fire.)NOTE 3Experience has found some MCH meeting the purity specification but which does not meet Ignition DelayARV (typically 1 to 1.5 millisecondsshorter). It is recommende
