engine technology progress in japan - diesel engines

Two-Stage Fuel Injection to Produce PCI Combustion andEliminate an Aftertreatment Device

Combustion Improvement with Multiple Injections in a Highly Boosted,High-EGR Diesel Engine

Investigation into Combustion and Exhaust Emissions with Late Intake ValveClosure Timing in a Light-Duty Diesel Engine

CO-LIF Measurement and Numerical Analysis to Investigate CO Production inLow-Temperature Oxidation Combustion

Cold-Start Emissions and Exhaust Gas Odor in a Diesel Engine withAftertreatment Devices

Investigation into N2O Emissions in the Latest Urea-SCR-Equipped

Diesel TruckHino Light- and Medium-Duty Trucks with a HC-SCR Integrated DPF System

ENGINE TECHNOLOGY

PROGRESS IN JAPAN

COMPRESSION-IGNITION

ENGINE TECHNOLOGY

inter-Tech Energy Progress, Inc.San Antonio, Texas, U.S.A.

April 2012

ISSN 1085-6919

ii

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PREFACE

inter-Tech Energy progress, Inc. (iTEP) incooperation with the Society of Automotive Engineersof Japan is totally dedicated to contribute to anincreased flow of engine technological data fromJapan and assist engine engineers in foreign countriesin maintaining an awareness of Japanese enginetechnology progress. The professionals at iTEP arecommitted to accomplish the above objectives.

iTEP publishes two reports per year in April andOctober each on the following three disciplines.

Alternative Fuels and Engines Compression-Ignition Engine Technology Spark-Ignition Engine Technology

Each semiannual report consists of three parts;1) executive summary for a quick reference of thereport contents, 2) main body of the reportsummarized and organized into similar topics, and 3)a list of literature referenced in the report. The reportis written to inform the reader of the valuable essenceof referenced literature sources available throughengineering societies and technical periodicals inJapan. iTEP screens the literature, analyzes thecontents, and selects them for the report. We writethe report in our own words so that readers canefficiently acquire the most valuable information. Yet,the report contains sufficient technical data includingtables and figures useful for engineering study on eachtopic. Therefore, the report is just not an assembly ofliterature directly translated from Japanese intoEnglish. The report is well organized for the selectedtopics and is a stand alone technical document.

We greatly appreciate your comments andsuggestions on the contents of the report. Therefore,please feel free to contact iTEP at the followingnumbers.

Thank you very much for your interest in "ENGINE

TECHNOLOGY PROGRESS IN JAPAN".

inter-Tech Energy Progress, Inc.13423 Blanco Road, No.207San Antonio, Texas 78216-2187, U.S.A.Telephone: 210-408-7508Facsimile: 210-568-4972email: [email protected]

ENGINE TECHNOLOGY PROGRESS IN JAPAN

PUBLISHER

Susumu ArigaEditor / Consulting Engine Engineerinter-Tech Energy Progress, Inc.San Antonio, Texas, U.S.A.

TECHNICAL ADVISORY BOARD(alphabetical order)

Mr. Brent K. BaileyExecutive DirectorCoordinating Research Council, Inc.Alpharetta, Georgia, U.S.A.

Emeritus Prof. Hiroyuki Hiroyasu, Ph.D.The University of Hiroshima, Hiroshima, JapanProfessor, Kinki University, Hiroshima, JapanPresident, Hiro Technology Brain(HTB), Inc.President, Hiroshima University CooperativeResearch CenterChairman of Engine Systems Division of JSME andInstitute of Liquid Atomization and Spray SystemsFellow of SAE

Emeritus Prof. Takeyuki Kamimoto, Ph.D.Tokyo Institute of Technology, Tokyo, JapanCo-Chairman of Engineering FoundationConference 1991 and 1993Fellow of SAE

Mr. Akinori MiuraSenior Chief EngineerEngine Research and Development DivisionNissan Diesel Motor Co., Ltd.Ageo-Shi, Saitama-Ken, Japan

EXECUTIVE

SUMMARY

v Copyright © 2012 inter-Tech Energy Progress, Inc.

1.0 TWO-STAGE FUEL INJECTIONTO PRODUCE PCICOMBUSTION ANDELIMINATE ANAFTERTREATMENT DEVICE

D-SPIA Combustion Tests DemonstrateEmissions Suitable for Euro 6 EmissionsStandards (ETPJ NO. 22012041): In effortsto reduce nitrogen oxides (NOx) without usingan aftertreatment device, engineers at ToyotaIndustry Corporation investigated the premixcompression ignition (PCI) combustion systemto examine its potential without significant enginemodifications. The fuel injection pattern wassplit into two stages to enhance oxidation ofunburned fuel in lean-mixture combustion. Theydesignated this combustion system “diesel-staggered premixed ignition with acceleratedoxidation” (D-SPIA) combustion.

A 2.2-liter, four-cylinder DI diesel enginewas modified to reduce the compression ratioto 15.0, and the engine was operated with PCI

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combustion to characterize the two-stage fuel injectionpattern for effects on exhaust emissions and fuelconsumption. Results indicated that the two-stage fuelinjection controlled the heat release rate pattern in favorof reducing nitrogen oxides (NOx), unburned fractions ofhydrocarbon (HC), and carbon monoxide (CO). Thetwo-stage fuel injection increased the flexibility ofcontrolling the heat release rate and enhanced combustionto raise the temperature later. However, the secondaryinjection had to occur at the appropriate timing duringcombustion, and optimum timing was determined in termsof exhaust emissions, combustion noise, and fuelconsumption.

Under high load, secondary fuel injection produceddiffusion combustion because the premix duration wasreduced, causing that fuel to burn during injection. Anapproach to reduce cylinder gas temperature wasconsidered, and a cooler for exhaust gas recirculation(EGR) was designed to improve cooling efficiency.Compared to other approaches such as a lowercompression ratio and a low-pressure loop exhaust gasrecirculation (EGR) system, using a highly efficient EGRcooler requires no significant engine modifications. Thecooler reduced intake charge temperature by about 6°Cand effectively increased the premix duration of thesecondary fuel injection. Thus, the engine could operatewith D-SPIA combustion over a wide operating range.

A production 2-liter, four-cylinder DI diesel enginewas tested for D-SPIA combustion to evaluate the exhaustemissions under European test conditions. Despite therelatively higher compression ratio of 15.8, exhaustemissions were reduced below Euro 6 emissionsstandards.

This chapter reports the concept of D-SPIAcombustion and its application to a production engine andthe engine test results.

2.0 COMBUSTION IMPROVEMENT WITHMULTIPLE INJECTIONS IN A HIGHLYBOOSTED, HIGH-EGR DIESEL ENGINE

Parametric Tests of After-Injection DemonstrateImproved Fuel Economy and Emissions (ETPJ NO.22012042): While hybrid and alternative fuel technologies

HEAT RELEASE RATE PATTERN

CONCEPTUALIZED FOR D-SPIACOMBUSTION SYSTEM

[Kuzuyama et al.]

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COMPRESSION-IGNITION ENGINE TECHNOLOGY

April 2012

have been developed to reduce fuel consumption andexhaust emissions including carbon dioxide (CO

2),

improvement of thermal efficiency for the base dieselengine remains the basic requirement for increasing overallvehicle fuel efficiency while keeping exhaust emissions low.Designing an engine that operates with high boost, highbrake mean effective pressure (BMEP), and high peakcylinder pressure accomplishes both high fuel efficiencyand low exhaust emissions. Thus, technologies developedat New Advanced Combustion Engineering, Inc. (NACE)for the super clean diesel engine (SCDE) project are onthe right path to continued development of a diesel enginewith better fuel efficiency and low exhaust emissions.

NACE researchers conducted experiments to evaluatethe effectiveness of multiple injections to improve enginethermal efficiency. Exhaust gas temperature was alsoexpected to increase so that the aftertreatment device couldbe more active to reduce exhaust emissions at tail pipeefficiently. They focused their investigation on combustionwith multiple injections, particularly on the role of after-injection combined with pilot injection. A small amount offuel was injected almost immediately after end of the mainfuel injection. While both pilot (and/or pre-injection) andmain fuel injection parameters were fixed, the after-injection timing and quantity were varied to evaluate effectson fuel consumption and exhaust emissions.

A two-liter, single-cylinder, direct-injection (DI) dieselengine was equipped with an external supercharger andan EGR system. A common-rail fuel injection system wasused to enable multiple injections. The engine wasoperated at 1,200 rpm with 40 percent load. After-injection of 20 mm3/stroke at timing closer to end of themain injection reduced brake specific values of both fuelconsumption and NOx. When the pilot injection timingwas adjusted to ignite pre-injected fuel at the same timeas the main fuel, brake specific fuel consumption (BSFC)slightly improved. Using both pre- and after-injections,BSFC and BSNOx could be reduced by 2 and 42 percent,respectively, compared to combustion with single injectionat top dead center (TDC).

Multiple injections decreased production of smokeand enabled the use of a higher EGR rate. Increasing theEGR rate to more than 50 percent effectively reducedcombustion temperature, decreasing heat loss which

NEEDLE LIFT PATTERNS [Osada et al.]

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benefitted improvement of fuel economy. Increasing thefuel flow rate through the fuel injection nozzle allowedfurther advancement of the after-injection timing near theend of main injection and contributed to decreased fuelconsumption by about 1 percent.

According to the combustion photographs, the after-injected fuel burned in the center of combustion chamber,and the flame diminished before it reached the walls. Withan EGR rate of 65 percent, combustion of the main-injected fuel extended, and the after-injection occurredbefore the main combustion ended. With the after-injection, the combustion area appeared to expandthroughout the combustion chamber. Heat generated bythe complete combustion probably distributed over awider area than combustion with the single injection. Thus,heat loss was lower, improving fuel economy and airutilization which reduced the production of smoke.

This chapter reports parametric test resultsdemonstrating the effects of after-injection and a discussionof the results including combustion photographs to explainreasons for improved fuel economy and lower exhaustemissions when multiple injections were used.

3.0 INVESTIGATION INTO COMBUSTIONAND EXHAUST EMISSIONS WITH LATEINTAKE VALVE CLOSURE TIMING IN ALIGHT-DUTY DIESEL ENGINE

Late Intake Valve Closure Timing DemonstratesPotential for Reduced Fuel Consumption andEmissions (ETPJ NO. 22012043): A highercompression ratio effectively improves thermal efficiencyin a reciprocating engine. However, in the interest ofreducing exhaust emissions and improving fuel economy,recent diesel engines employ a reduced compression ratioto achieve this advantage. A lower compression ratioreduces peak cylinder gas temperature and engine friction.Thereby, NOx emissions are reduced, and fuel economyis improved. Engineers at Isuzu Advanced EngineeringCenter investigated the potential of improving thermalefficiency with a lower compression ratio and conductedparametric tests to observe the effect of increasedexpansion ratio on both exhaust emissions and fueleconomy. This approach is similar to the so-called “Miller

COMBUSTION FLAME PATTERN

[Osada et al.]

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cycle.” Intake valve closure timing was retarded by 40crank angle degrees. As a result, the effective compressionratio decreased from 16.1 to 11.9.

Operating the engine using the Miller cycle with lateintake closure timing improved indicated thermal efficiencyunder both low-load and medium-load at high speed sincepumping loss could be reduced. By increasing boostpressure to compensate for the loss of intake air flow dueto the late intake valve closure timing, combustion nearTDC became more active, increasing the degree ofconstant volume combustion. Thus, fuel consumption wasabout the same as that of an engine operating with normalintake valve closure timing although exhaust emissionswere reduced.

Under low-load at medium speed, both fuelconsumption and soot decreased. As both engine speedand load were increased, both fuel consumption and sootincreased when the engine was operated with the sameboost pressure as the engine with normal intake valveclosure timing. Increasing the boost pressure improvedboth fuel consumption and soot to levels equal to those inengine operation with normal intake valve closure.

A comparison of results for the same NOx levelbetween the two intake closure timings reveals that engineoperation with the late intake valve closure timingdecreased both fuel consumption and soot under JE05transient operating conditions. According to thefrequencies of engine torque and speed during JE05transient operation, the engine was operated morefrequently at relatively low load. Thus, the engine operationwith the late intake valve closure timing improved bothfuel consumption and soot because the late intake valveclosure timing was more effective under low load thanunder medium and high load.

This chapter repots parametric test results and someanalysis such as heat balance to discuss the engine testresults obtained with the late intake valve closure timing.

BSFC AND SOOT AS A FUNCTION OF NOX

RELATIVE TO THOSE OF ENGINE OPERATION

WITH NORMAL INTAKE VALVE CLOSURE

TIMING [Gomi et al.]

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4.0 CO-LIF MEASUREMENT ANDNUMERICAL ANALYSIS TOINVESTIGATE CO PRODUCTION INLOW-TEMPERATURE OXIDATIONCOMBUSTION

CO Production Determined by Conditions outsidethe Oxidation Range (ETPJ NO. 22012044): Dieselcombustion technology using high EGR simultaneouslyreduces both NOx and soot and improves the trade-offbetween NOx and soot. Because high EGR reducescombustion gas temperature, CO remains incompletelyoxidized during combustion and becomes a toxiccomponent of exhaust emissions. In response to this issue,research into CO tailpipe emissions before the catalyst iswarmed up and active has been conducted at various sites.

Engineers at Toyota Group investigated factors of COproduction in order to understand technical approachesto reduce CO. The laser-induced fluorescence (LIF)technique was used to visualize CO in a transparent engine.The results of the CO-LIF measurement were used tovalidate a numerical simulation tool. About 10 percenterror in the prediction of CO concentration was determineddue to the assumption that the numerical analysis ignoredthe effect of unburned hydrocarbons in the oxidationprocess of CO. Therefore, qualitative observations ofthe fluorescence images were performed. Investigationsusing both measurement and simulation were conductedfor low-load operating conditions while only numericalanalysis was performed for high-load operating conditionsbecause the measurement was not feasible in combustionat high temperature.

That pilot-injected fuel that remained present betweenthe main fuel sprays became the source of CO becausethe temperature would not reach 1,500°K simply fromthe heat released by the pilot-injected fuel. In other words,the excessively distributed pilot-injected fuel producedCO under low load. The dispersion of pilot-injected fuelneeds to be minimized to reduce the amount of unburnedfuel between main-injected fuel sprays. A means ofenhancing mixing of such fuel with high-temperature gasis necessary to increase the mixture temperature to thelevel required for CO oxidation.

As the piston descends, both equivalence ratio and

CO GAS PLOTTED IN THE RELATIONSHIP

BETWEEN THE EQUIVALENCE RATIO AND

TEMPERATURE [Fuyuto et al.]

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temperature decreased more noticeably under high load.However, the equivalence ratio did not decrease belowthe stoichiometric ratio of 1 even at 60°CA ATDC, andthe gas conditions were outside the range necessary forCO oxidation. Therefore, the relatively rich gas couldnot oxidize CO even though the temperature was relativelyhigh, and the mixing rate of gas containing CO with freshair needs to be increased to reduce CO under high load.

The chapter reports the methodology of CO-LIFmeasurement, numerical simulation techniques withvalidation, and investigation results of the CO productionprocess under both low- and high-loads.

5.0 COLD-START EMISSIONS ANDEXHAUST GAS ODOR IN A DIESELENGINE WITH AFTERTREATMENTDEVICES

Sources of Smoke, Odor, and HCHO in ExhaustGas Determined in Low-Temperature Engine Tests(ETPJ NO. 22012045): Aftertreatment technology hasmade significant contributions to the reduction of tailpipeexhaust emissions and enabled diesel engines to complywith stringent regulatory requirements. A group ofresearchers from Kitami Institute of Technology, AishinIndustries, and Isuzu Motor Corporation questioned howaftertreatment devices work at cold start in low-temperature ambient conditions.

Recent diesel engine design trends include reducingthe compression ratio to improve fuel economy and moreaggressively using the low-temperature oxidation reactionis to reduce exhaust emissions. These trends reducecombustion gas temperature and increase a fraction ofincompletely burned fuel in the exhaust gas. At sub-freezing temperatures, the aftertreatment device might notreduce this incompletely burned fuel effectively, thuscausing white smoke and exhaust gas odor to increase.The catalyst is not simply ready to perform the oxidationreaction at such low temperatures.

Researchers tested a 3-liter, inline-four cylinder dieselengine equipped with a diesel oxidation catalyst (DOC)and a diesel particulate filter (DPF) at various lowtemperatures, e.g., –10 to – 30°C and evaluated unburnedHC, CO, formaldehyde (HCHO), and exhaust gas odor

THE EFFECT OF AMBIENT TEMPERATURE ON

WHITE SMOKE WITH AND WITHOUT

AFTERTREATMENT DEVICES DURING COLD

START AND WARM-UP PERIOD

[Yamada et al.]

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upstream and downstream from the aftertreatment devices.The engine was operated on Japan Industrial Standard(JIS) No. 3 diesel fuel that contained a fraction of kerosene.

At ambient temperatures of –25 and –30°C, unburnedHC was adsorbed in the aftertreatment devices duringthe engine cranking and probably desorbed about 40seconds after the engine was cranked. This caused theconcentration of unburned HC to increase at the tailpipeeven though the level was low before 40 seconds. Sinceprecious metals used for the aftertreatment devices adsorbCO, it was believed that the catalysts used for DOC alsoadsorb CO. However, the concentration of CO was toohigh, causing the adsorption of CO to be saturated. As aresult, the difference in the concentration of CO beforeand after the aftertreatment was probably not clearlyindicated in the data.

As the ambient temperature decreases, the saturatedconcentration of vapor decreases, and frost on theaftertreatment devices increases. Thus, the lower theambient temperature, the longer white smoke would beexhausted and the higher the level of white smokeproduced. At –25 and –30°C, white smoke wassignificantly high for about 40 seconds after it began toincrease, which corresponded to the increase in unburnedHC observed at the same time. Thus, unburned HC wasprobably the source of white smoke. On the other hand,at the relatively higher temperatures of –10 and –20°C,the engine started relatively earlier after the engine wascranked. The amount of unburned HC that had adheredto the aftertreatment device was probably lower; theincrease in the level of white smoke was not particularlyobserved.

According to the distillation characteristics of JIS No.3 diesel fuel, this fuel contains kerosene; however, only afraction of kerosene evaporated in the exhaust gas at about40°C. Thus, most of the unburned HC adsorbed in theaftertreatment devices probably did not desorb duringengine cranking and became the source of white smokewhen the engine started.

The concentration of HCHO was higher as the ambienttemperature was lower. Compared to the concentrationmeasured upstream from the aftertreatment devices, theconcentration measured downstream was lower. It isbelieved that HCHO was adsorbed in the oxidation

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catalyst, causing the apparent conversion rate to increase.Thus, the concentration became lower downstream fromthe aftertreatment device.

The rating of odor was lower as well in exhaust gassampled downstream from the aftertreatment devicesespecially during the initial period of engine start. Exhaustgas temperature downstream from the aftertreatmentdevice stepped up at 5 to 6 minutes after engine start.Thus, the frost on the aftertreatment devices completelyvaporized. In other words, in 5 to 6 minutes during enginewarm-up, water must have been present in theaftertreatment devices, and major components of exhaustgas odor, such as aldehyde, were trapped in the frost.Therefore, the rating was relatively low during the initialengine start period of 1 to 2 minutes before the exhaustgas temperature increased.

This chapter reports experimental study results ofexhaust emissions and odor evaluated in a diesel engineoperated at ambient temperatures as low as –35°C.

6.0 INVESTIGATION INTO N2O EMISSIONS

IN THE LATEST UREA-SCR-EQUIPPEDDIESEL TRUCK

Increased Volume in Aftertreatment DevicesDemonstrates Improved Emissions (ETPJ NO.22012046): Most recent diesel vehicles are equippedwith a urea selective catalytic reduction (SCR) system toreduce NOx to meet regulatory requirements. The ureaSCR produces nitrous oxide (N

2O). A diesel vehicle so-

equipped emits N2O emissions of about 15 to 20 percent

CO2-equivalent greenhouse gas (GHG) loads in the

atmosphere. The source of N2O has been identified in

the oxidation of ammonia in the urea SCR system.However, N

2O is not regulated in Japan. Researchers at

The National Traffic Safety and Environment Laboratories(NTSEL) tested three 2009 model year vehicles tocharacterize N

2O emissions and studied them under JE05

transient test conditions and World Harmonized TransientCycle (WHTC) test conditions. For comparison, two2005 model year vehicles equipped with the urea SCRsystem were also tested.

The further reduction of NOx emissions with a ureaSCR system has generally been known to increase N

2O

N2O EMISSIONS [Suzuki et al.]

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emissions if NOx reduction performance is to beimproved. N

2O is produced through the oxidation reaction

of ammonia on the SCR catalyst. Thus, increasing theamount of ammonia to improve NOx reductionperformance was thought to increase N

2O emissions.

However, recent vehicles equipped with the urea SCRsystems significantly reduced N

2O emissions, according

the test results.N

2O was in the range of about 0.03 to 0.14 g/kWh

under both JE05 and WHTC test conditions. This levelof N

2O is less than 5 percent CO

2-equivalent global

warming load and is significantly lower than that of a 2005model year vehicle. Under JE05 test conditions, thetemperature profile is quite different between the 2005and 2009 vehicles, although the average temperature wasabout the same. Exhaust gas temperature at tailpipe ofthe 2005 model (Vehicle NTL1) varied from 140 to morethan 250°C while the 2009 model (Vehicle A) did notchange the exhaust gas temperature more than ± 20°C of200°C. These differences between the two vehicles wereattributed to the difference in the volume of aftertreatmentdevice upstream from the urea SCR system.

The greater volume of aftertreatment device upstreamfrom the urea SCR system on Vehicle A due to the additionof an oxidation catalyst and a diesel particulate filter (DPF)delayed the rise of exhaust gas temperature by about 100seconds when the vehicle was accelerated and operatedat a high speed. Not only that, the peak temperature waslower by about 20°C. As emissions standards becamemore stringent in 2009, vehicles are equipped with boththe urea SCR system and DPF. Consequently, this trendhelped reduce N

2O emissions, leading to lower global

warming effect.This chapter reports a discussion of N

2O emissions

based on the test results and a comparison between JE05and WHTC on both criteria emissions and N

2O.

7.0 HINO LIGHT- AND MEDIUM-DUTYTRUCKS WITH A HC-SCR INTEGRATEDDPF SYSTEM

Various Technologies Employed for ImprovedEmissions and Fuel Consumption in Anticipationof More Stringent Regulations (ETPJ NO.

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22012047): Hino engineers report technologiesdeveloped for a medium-duty diesel engine (J05E) and alight-duty diesel engine (N04C) to meet Japan’s 2009emissions standards: NOx emissions of 0.7 g/kWh andparticulate emissions of 0.01 g/kWh. Development wasalso pursued to improve the fuel economy standard thatwill be mandated in 2015 in Japan.

Technologies were developed to improve combustion,EGR, and aftertreatment. For light-duty engines, additionaltechnologies were developed to reduce noise at idle aswell as fuel consumption at idle for hybrid vehicleapplications. NOx of the 5.123-liter inline four-cylinderJ05E engine was sufficiently reduced to meet Japan’s 2009standard while particulate was kept low. High torque atlow speed, combustion improvement, and optimizationof the transmission gear ratio could improve fuel economyby 7 percent for the medium-duty J05E diesel engine.

Instead of the urea SCR, a HC SCR was developedand integrated with a DPF system. The engine electroniccontrol unit (ECU) estimates the exhaust gas conditionsto supply the optimal amount of diesel fuel to the fuelinjection nozzle upstream from the oxidation catalyst infront of the DPF. Information used for this estimateincludes temperature and NOx sensor output. Despitethe additional DOC used for the system, the increase inthe entire length was limited to about 50 mm. The HC-SCR integrated DPF system effectively reduced both NOxand particulate to shift the trade-off into the 2009 standards.

The Atkinson cycle was used to increase the expansionratio of the 4-liter inline four-cylinder, light-duty, N03Cdiesel engine for hybrid vehicle application. Intake valveswere closed at a later timing to reduce the effectivecompression ratio. This relatively simple approachimproved fuel economy at idle by 5 percent. Overall fueleconomy under light-load transient cycle conditionsimproved about 3 percent. Since a variable valve timingdevice was not used for this approach, the engineperformance and fuel economy under high load suffer.However, motor-assisted engine operation could producesufficient powertrain performance to propel the vehicle.

This chapter reports various technologies developedfor both light- and medium-duty diesel engines to reduceboth exhaust emissions and fuel consumption.

A HC-SCR INTEGRATED DPF SYSTEM

COMPARED WITH A DPF SYSTEM

[Hisatomi et al.]

HINO J05E ENGINE EQUIPPED WITH A HC-SCR INTEGRATED DPF SYSTEM

[Hisatomi et al.]

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TABLE OF CONTENTSPage

PREFACE ............................................................................................................................. iii

EXECUTIVE SUMMARY ................................................................................................... v

TABLE OF CONTENTS .................................................................................................... xvii

1.0 TWO-STAGE FUEL INJECTION TO PRODUCE PCICOMBUSTION AND ELIMINATE AN AFTERTREATMENTDEVICE ................................................................................................... 1

1.1 PCI COMBUSTION WITH TWO-STAGE FUEL INJECTION TOREDUCE ENGINE-OUT NOx ....................................................................... 2

1.1.1 Characterization of D-SPIA Combustion ................................................. 31.1.2 Application of D-SPIA Combustion to a Production 2-Liter Diesel

Engine .................................................................................................... 7

2.0 COMBUSTION IMPROVEMENT WITH MULTIPLEINJECTIONS IN A HIGHLY BOOSTED, HIGH-EGRDIESEL ENGINE ................................................................................. 13

2.1 INVESTIGATION INTO THE ROLE OF AFTER-INJECTION INCOMBUSTION WITH MULTIPLE INJECTIONS ................................... 14

2.1.1 Fuel Consumption and Exhaust Emissions .............................................. 162.1.2 Combustion Study ................................................................................ 22

3.0 INVESTIGATION INTO COMBUSTION AND EXHAUSTEMISSIONS WITH LATE INTAKE VALVE CLOSURE TIMINGIN A LIGHT-DUTY DIESEL ENGINE.............................................. 27

3.1 EXPERIMENTAL INVESTIGATION THROUGH PARAMETRICTESTS ............................................................................................................ 28

3.1.1 Test Results under Steady-State Operating Conditions ........................... 30

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TABLE OF CONTENTS(cont'd.)

Page

3.1.2 Heat Balance ........................................................................................ 343.1.3 Verification under JE05 Transient Operating Conditions ......................... 37

4.0 CO-LIF MEASUREMENT AND NUMERICAL ANALYSIS TOINVESTIGATE CO PRODUCTION IN LOW-TEMPERATUREOXIDATION COMBUSTION ............................................................ 39

4.1 INVESTIGATION INTO THE CO PRODUCTION MECHANISM INLOW-TEMPERATURE OXIDATION COMBUSTION............................ 40

4.1.1 CO Measurement with LIF ................................................................... 404.1.2 Numerical Simulation ............................................................................ 424.1.3 Factors Affecting CO Production .......................................................... 47

5.0 COLD-START EMISSIONS AND EXHAUST GAS ODORIN A DIESEL ENGINE WITH AFTERTREATMENTDEVICES ............................................................................................... 51

5.1 EXPERIMENTAL STUDY OF AFTERTREATMENT PERFORMANCEAT SUB-ZERO TEMPERATURES ............................................................. 53

5.1.1 Test Apparatus and Test Procedure ....................................................... 535.1.2 Test Results .......................................................................................... 54

6.0 INVESTIGATION INTO N2O EMISSIONS IN THE LATEST

UREA-SCR-EQUIPPED DIESEL TRUCK ...................................... 63

6.1 MEASUREMENT OF N2O UNDER JE05 AND WHTC FOR

THREE DIFFERENT VEHICLES AND TWO DIFFERENTENGINES ...................................................................................................... 64

6.1.1 Criteria Emissions ................................................................................. 656.1.2 N

2O Emissions ..................................................................................... 66

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7.0 HINO LIGHT- AND MEDIUM-DUTY TRUCKS WITH AHC-SCR INTEGRATED DPF SYSTEM .......................................... 71

7.1 TECHNOLOGIES DEVELOPED FOR VARIOUS APPLICATIONS TOMEET 2009 EMISSIONS STANDARDS ................................................... 72

7.1.1 A Medium-Duty Diesel Engine (J05E) with a HC-SCR integratedDPF System ......................................................................................... 72

7.1.2 A Light-Duty Diesel Engine (N04C) with a HC-SCR integratedDPF System ......................................................................................... 78

REFERENCES ............................................................................................... 85

TABLE OF CONTENTS(cont'd.)

Page


Chapter 7, April 2012

85 Copyright © 2012 inter-Tech Energy Progress, Inc.

ETPJ No. 22012047

1.0 TWO-STAGE FUEL INJECTIONTO PRODUCE PCICOMBUSTION ANDELIMINATE ANAFTERTREATMENT DEVICE

Kuzuyama, H., M. Machida, T. Kawae, andT. Unehara, Toyota Industry Corporation,“High Efficiency and Clean DieselCombustion Using Double PremixedIgnition (First Report) - Development ofA New Combustion Concept AndPotential Of Emission Reduction,”JSAE* Paper No. 20115544, October2011.

2.0 COMBUSTION IMPROVEMENTWITH MULTIPLE INJECTIONSIN A HIGHLY BOOSTED, HIGH-EGR DIESEL ENGINE

Osada, H., Y. Aoyagi, and K. Shimada, NewAdvanced Combustion Engineering, Co.,Ltd., “Diesel Combustion ImprovementUsing High Boost, Wide Range and HighRate EGR in a Single Cylinder Engine(Third Report) – Effect of Multi-Injectionon Exhaust Emissions and BSFC,” JSAEPaper No. 20115558, October 2011.

3.0 INVESTIGATION INTOCOMBUSTION AND EXHAUSTEMISSIONS WITH LATEINTAKE VALVE CLOSURETIMING IN A LIGHT-DUTYDIESEL ENGINE

Gomi, T. and N. Ishikawa, Isuzu AdvancedEngineering Center, “The Effects onEngine Performance with Late IntakeValve Close Timing in a Light-Duty DieselEngine for Commercial Vehicle,” JSAEPaper No. 20115753, October 2011.

4.0 CO-LIF MEASUREMENT ANDNUMERICAL ANALYSIS TOINVESTIGATE COPRODUCTION IN LOW-TEMPERATURE OXIDATIONCOMBUSTION

Fuyuto, T., R. Ueda, T. Matsumoto, Y. Hattori,J. Mizuta, and K. Akihama, Toyota CentralR&D Labs.; H. Aoki and T. Umehara,Toyota Industry Corporation; and H. Itoand A. Kawaguchi, Toyota MotorCorporation, “Analysis of CO EmissionsSources in Diesel Combustion (SecondReport) – Validation of NumericalSimulation and Analysis of CO EmissionSources,” JSAE Paper No. 20115631,October 2011.

REFERENCES

NOTE: English titles are provided by the original authors.

* JSAE: Society of Automotive Engineers of Japan


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5.0 COLD-START EMISSIONS ANDEXHAUST GAS ODOR IN ADIESEL ENGINE WITHAFTERTREATMENT DEVICES

Yamada, K, K. Hayashida, and H. Ishitani,Kitami Institute of Technology; J. Matuoka,Aishin Industries; and H. Yamada and T.Minami, Isuzu Motor Corporation, “Effectof Diesel Exhaust Aftertreatment Systemon Exhaust Gas Emissions During ColdStarting,” JSAE Paper No. 20115737,October 2011.

6.0 INVESTIGATION INTO N2O

EMISSIONS IN THE LATESTUREA-SCR-EQUIPPED DIESELTRUCK

Suzuki, H. and H. Ishii, National Traffic Safetyand Environment Laboratories, “N

2O

Emissions Characteristics of Post NewLong Term Urea SCR Vehicles,” JSAEPaper No. 20115695, October 2011.

7.0 HINO LIGHT- AND MEDIUM-DUTY TRUCKS WITH A HC-SCRINTEGRATED DPF SYSTEM

Hisatomi, K., Y. Toudou, H. Ohi, Y. Koyanagi,T. Kawasaki, and T. Ohya, Hino Motors,Ltd., “Development of New DieselEngine for Medium Duty CommercialVehicle Met Post New Long-TermExhaust Emission Regulations Withoutthe Urea-SCR,” JSAE Paper No.20115819, October 2011.

Mamiya, H., N. Suzuki, K. Oogimoto, I.Maeda, and K. Goto, Hino Motors, Ltd.,“Development of New Diesel Engine forLight-Duty Commercial Vehicle withoutUrea-SCR,” JSAE Paper No. 20115820,October 2011.

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