1、Designation: D6890 15aD6890 15bStandard 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
2、the 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 th
3、e 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 S15, No. 1-D S500, andNo. 1-D S5000, and grades No. 2-D S15, No. 2-D S500, and No. 2-D S5000 diesel fuel oils, European standard EN 590, andCanadian standards CAN/CGSB-3.517 and 3.6-2000. The test method may also be applied to the quantitative determination of theignition characteristics of diese
5、l fuel blending components.1.2 This test method measures the ignition delay of a diesel fuel injected directly into a constant volume combustion chambercontaining heated, compressed air.An equation correlates an ignition delay determination to cetane number by Test Method D613,resulting in a derived
6、 cetane number (DCN).1.3 This test method covers the ignition delay range from 3.1 ms to 6.5 ms (64 DCN to 33 DCN). The combustion analyzer canmeasure shorter and longer ignition delays, but precision may be affected. For these shorter or longer ignition delays the correlationequation for DCN is giv
7、en in Appendix X2. There is no information about how DCNs outside the 33 to 64 range compare to TestMethod D613 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 a
8、ll of the safety concerns, if any, associated with its use. It is the responsibilityof 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
9、Cetane Number of Diesel Fuel OilD975 Specification for Diesel Fuel OilsD1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4175 Terminology Relating to Petroleum Products, Liquid Fuels, and LubricantsD4177 Practice for Automatic Sampling of Pet
10、roleum and Petroleum ProductsD5854 Practice for Mixing and Handling of Liquid 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
11、 Precision and Bias Data for Use in Test Methods for Petroleum Products and LubricantsD6708 Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purportto Measure the Same Property of a Material1 This test method is under the jurisdiction ofASTM Com
12、mittee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.01 on Combustion Characteristics.Current edition approved Oct. 1, 2015Dec. 1, 2015. Published October 2015February 2016. Originally approved in 2003. Last previous edition approved in 2
13、015 asD6890 15.D6890 15a. DOI: 10.1520/D6890-15A.10.1520/D6890-15B.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, L
14、ondon, W1G 7AR, UK. Adapted with permission of Energy 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 websi
15、te.This document is not an ASTM standard and is intended 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
16、editions as appropriate. In all cases only the current 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-
17、2959. United States1E456 Terminology Relating to Quality and Statistics2.2 ISO Standards:4ISO 4010 Diesel 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 FuelsDiesel
18、Requirements and Test Methods52.4 Energy Institute Standard:IP 41 Ignition Quality of Diesel FuelsCetane 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.
19、1.1 accepted reference value (ARV), nvalue that serves as an agreed-upon reference for comparison and that 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
20、 U.S. National Institute of Standards and Technology (NIST), or (3) a consensusvalue, based on collaborative 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 ign
21、ition delay of specific referencematerials determined under reproducibility conditions by collaborative 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
22、biodiesel fuel with diesel fuel oils.3.1.3.1 DiscussionIn the abbreviation, BXX, the XX represents the volume 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 e
23、ngine test. D41753.1.4.1 DiscussionIn the context of this test method, cetane number is that defined by 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 contex
24、t of this test method, check standard refers to heptane.3.1.6 quality control (QC) sample, nfor use in quality 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
25、 those oftypical samples tested by the analytical measurement system. The material is properly stored to 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, npur
26、e chemical having an assigned ignition delay accepted reference value.3.2.2 charge air, ncompressed air at a specified pressure introduced to the combustion chamber at the beginning of each testcycle.4 Available from American National Standards Institute, 25 W. 43rd St., 4th floor, New York, NY 1003
27、6.5 Available 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 15b
28、23.2.3 charge air temperature, ntemperature, in C, of the air inside the combustion chamber.3.2.4 combustion 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 equat
29、ion to determine a cetane number.3.2.5.1 DiscussionThe conversion equation relates a measured ignition delay 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
30、and the start ofcombustion as determined using the specific combustion analyzer applicable for this test 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; st
31、art of combustion is interpreted as that point in the combustion cycle when a significant andsustained increase 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 s
32、uccessive calibration or QC testing, or both, of the combustionanalyzer 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 control.4. Summary of Test Method4.1 A small specimen of diesel
33、 fuel oil is injected into a heated, temperature-controlled constant volume chamber, which haspreviously 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 o
34、f significant combustion for each cycle. A completesequence comprises 15 preliminary cycles and 32 further 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 numberb
35、y Test Method D613.5. Significance and Use5.1 The ID and DCN values determined by this test method can provide 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 comme
36、rce as a specification aidto relate or match fuels and engines. It can also be useful in research or when there is interest in the ignition delay of a diesel fuelunder the conditions of this test method.5.3 The relationship of diesel fuel oil DCN determinations to the performance of full-scale, vari
37、able-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 user is therefore cautioned to investigate the suitabili
38、ty 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 min on a fit-for-use instrument.D6890 15b36. Interfere
39、nces6.1 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 these fuels and materials to UV wavelengths sho
40、rter than 550 nanometers for a short period of time maysignificantly affect ignition delay measurements.NOTE 1The formation 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
41、of less than 10C, and covered by a blanket of nitrogen.6.2 Statistical analysis of data from a sequential testing study (Note 2) revealed a possible carryover effect in succeeding testson samples containing 2ethylhexylnitrate cetane improver at concentrations above 2000 ppm.NOTE 2In the sequential t
42、esting study, a fuel without cetane improver was tested three times back-to-back.Then a fuel with 2ethylhexylnitrate 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
43、 were examined for evidence of hysteresis.7. Apparatus7.1 GeneralThis test method uses an integrated automated analytical measurement system9 comprised of: (1) a constantvolume compression ignition combustion chamber with external electrical heating elements, suitable insulation and pneumaticallyact
44、uated intake and exhaust valves, (2) a heated, pneumatically actuated fuel injection system10 with pump, injector nozzleassembly, and associated sample reservoir, (3) a coolant system with a liquid-to-air heat exchanger, filter, circulating pump andflow control valves, (4) temperature thermocouples,
45、 pressure gages and sensors, an injector nozzle needle motion sensor,compressed gas pressure regulators, control valves, pneumatic actuator components, and solenoid valves, and (5) a computer tocontrol test sequencing, acquire and accumulate sensor signal data, provide processing calculations, and a
46、utomatically output aprinted report of some important test parameters (see Fig. 1).7.2 See Annex A2, Combustion Analyzer 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
47、the downstream pressure to a minimum pressure of 2.2MPa.7.3.2 Actuator Utility Compressed Air Regulator, a two-stage 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 ca
48、pable 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 nominal poresize of 3 m to 5 m for use with a positive pressure delivery device s
49、uch as a glass syringe or glass-lined metal syringe.7.4.2 Positive Pressure Delivery Device, a non-reactive positive pressure delivery device such as a glass syringe or a glass-linedmetal syringe.8. Reagents and Materials8.1 Calibration Reference Materials: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 th
