powertrain testing in japan · engines and powertrains technical workshop 1 powertrain testing in...

独立行政法人交通安全環境研究所

National Traffic Safety and Environment Laboratory

Heavy Duty Vehicle Efficiency: Aligning Standards Internationally, Integration of

Engines and Powertrains Technical Workshop

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Powertrain Testing in Japan

Emission regulation, testing and engine technology trends

Hisakazu Suzuki National Traffic Safety and Environment Laboratory

JAPAN





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CONTENTS

1. Emission Regulation Trends in Japan

2. Test Cycle Transition

3. Change of Adopted Technologies for Actual Vehicles 4. Fuel Consumption standard and Vehicle test about it 5. Urea SCR Deterioration and Durability test 6. Problems in WHDC Introduction





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Emission regulation trends in Japan

•  For the last 20 years, the regulation has been reviewed 5 times. •  It will be even stricter in 2016. •  Sulfur concentration in fuel should also be reduced for emission

reduction devices

Nox PM

Short term '94 6 0.4 D -13 2000

Long term '98-99 4.5 0.25 D -13 500

New short term '03-04 3.38 0.18 D -13 50

New long term '05 2 0.027 JE05 10/50

Post new long term '09-10 0.7 0.01 JE05 10

Post post new long term '16-17 0.4 0.01 W HD C 10

Testcycle

Sulfercontents infuel w t ppm

Regulation title PeriodRegulation value g/kW h





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Test cycle #1, D-13 mode

u Steady state cycle consists of 13 operation point operations.

u Introduced in 1994

0 20 40 60 80 100 120Engine Speed (%)

0

20

40

60

80

100

120

Eng

ine

Load

(%)

1,4

2

3

5

6 7

89

10

11

12

13Idle





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Test cycle #2, JE05 mode

u Transient cycle represented in urban driving. u Engine speed and torque is determined based on the data

when a vehicle with the testing engine drives along the driving pattern.

u Low average speed → Difficult to keep catalyst activation u Introduced in 2005

0 200 400 600 800 1000 1200 1400 1600 1800 2000Time [s]

020406080

100

Vehi

cle

Velo

city

[km

/h]

Ave. speed 27.3 km/h





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Test cycle #3, WHDC (World Harmonized Heavy Duty Cycle)

u Combined with transient cycle (WHTC) and steady state cycle (WHSC).

u Engine speed and torque is determined based on the maximum torque curve of the testing engine.

u Combined with cold and hot start test. u Will be introduced in 2016 (in Japan)





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Technology trends for each regulation #1

Short term

Long term

Intake m anagem ent N.A., w/o EG R

Fuel injection system C om m on rail

Aftertreatm ent devices none

Intake m anagem ent N.A., EG R

Fuel injection system Jark inline

Aftertreatm ent devices none

World’s first

Most of HD vehicles used to have Natural Aspiration Engine.

Many vehicles adopted EGR, but conservative to adopt other technologies.





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New long term After treatment system is essential. Two major trends

Intake m anagem ent TC I, EG R


Aftertreatm ent devices DO C + DPF


Fuel injection system Unit injector

Aftertreatm ent devices DO C + urea SC R

GVW < 12 t

GVW > 12 t

EGR and DPF were equipped to meet the regulation

Some large vehicles equipped Urea SCR instead of DPF

World’s first





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Post new long term

GVW < 12 t

GVW > 12 t

Intake m anagem ent 2 stage TC I, EG R


Aftertreatm ent devices DO C + D PF



Aftertreatm ent devices D O C + DPF + urea SC R

Many vehicle meet regulation without Urea SCR and have 2 stage turbocharger.

All large vehicles have both DPF and Urea SCR.

DPF+SCR combo package





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Technology trends for the next step

It is now predicted vehicles with Urea SCR will grow in numbers, but vehicles not having Urea SCR will equip a lean NOx trap catalyst in the future. Why? Japan has quite a few diesel passenger vehicles. General gas stations cannot provide urea solution.

Basic system configurations will not be changed from the current ones. But, after treatment system has to be improved.

Prospective technologies：

l From the existing Fe-zeolite based catalyst to Cu-zeolite based catalyst l SCR catalyst coated DPF

GVW < 12 t

GVW > 12 t

To meet 2016 emission regulation...





Japan 2015 Fuel Efficiency Regulation for HDV

•  Introduced in 2006

•  As reference the situation in 2002, the value was determined after discussions of how the situation would be better by 2006.

•  Improve by average of 12%

Target value (averaged)

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2015 fuel economy targets for HDVs for each weight class

2.0120 <23.09≤201

Target Standard Values (km/L)Gross Vehicle Weight Range (t)Vehicle Category

2.0120 <23.09≤201

Target Standard Values (km/L)Gross Vehicle Weight Range (t)Vehicle Category

Tractor

3 <2 < & ≤3

1.5 < & ≤2≤1.5

Maximum LoadRange (t)

4.1516 < & ≤20104.9714 < & ≤1695.6912 < & ≤1486.0010 < & ≤127

7.247.5 < & ≤856.528 < & ≤106

9.5138.124

4.0420 <11

10.35210.83

3.5 < & ≤7.5

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Target StandardValues (km/L)

Gross VehicleWeight Range (t)

Vehicle Category

3 <2 < & ≤3

1.5 < & ≤2≤1.5

Maximum LoadRange (t)

4.1516 < & ≤20104.9714 < & ≤1695.6912 < & ≤1486.0010 < & ≤127

7.247.5 < & ≤856.528 < & ≤106

9.5138.124

4.0420 <11

10.35210.83

3.5 < & ≤7.5

1

Target StandardValues (km/L)

Gross VehicleWeight Range (t)

Vehicle Category

Other Than Tractor

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FC Test Method - Simulation

Fuel consumption for HDV is calculated using Simulation method. Preconditions for the calculation: u  Calculation target is vehicle. Not enough to improve only engine performance. Combination of engine and transmission is important. u  Regulation Target is for vehicle manufactures. Vehicles without loading plat home ; Cab and chassis u  To reduce workload, small things are neglected . e.g. Rolling resistant coefficient is set to the constant value based on the weight. u  Engine tests needs to create a fuel efficiency map by steady state

operation.

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Simulation method will be introduced later.





Measurement Method of Fuel Efficiency Map

•  Measured by steady state cycle on engine test bed •  Accept measurement by gas analyzer or fuel flow meter

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< Measurement points >

Idle

Friction torque

Max. torque

Rated speed

ü  Maximum torque ü  Friction torque ü  More than 5 loaded points in more than 6 engine speeds (More than 30+ points in total）

Fuel consumption measured





Adopt Measures against Defeat Strategy in 2013

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In 2011, defeat strategy was revealed by a HD truck: When it ran on a steady state driving for 4 minutes, the EGR control was changed.

Purpose is to improve fuel efficiency only at the engine test conducted for fuel efficiency map creation, while emission test is conducted with transient cycle.

Until now Fuel efficiency map was created by steady state operation. Based on the results, simulation calculated fuel consumption.

From now At the emission test, fuel consumption rate is additionally measured, and then validate whether the measurement values are equal to the fuel consumption by the simulation.

Countermeasures were launched from October, 2013.





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The Future of Emission Test

•  After 2016, the regulation value will not be tightened・・・The point is not the regulation value any more.

•  To maintain the emission performance of in-use vehicles is more important・・・ In 2018, WWH-OBD（equivalent to OBD-2 in the U.S.) will be introduced.

•  Durability test is the hottest topic under discussion.





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Current Durability Requirements

Durability requirement for HD vehicles

A couple of endurance test cycles were established. One of them is equivalent to the U.S. But, some of HD vehicles showed significant deterioration in performance with even less mileage than the durable mileage. In particular, the deterioration happened in Urea SCR.

G VW t D istance km < 8 2500008 - 12 45000012 < 650000

Causes of the deteriorations : 1.  HC poisoning 2.  DOC deterioration





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HC poisoning – major cause of deterioration

•  Zeolite based SCR catalyst would absorb not only ammonia, but also hydro-carbons　(HC).

•  In continuous idling or light load operating, the SCR catalyst surface would be covered with HC, and NOx reduction rate was deteriorated.

•  When the SCR catalyst is poisoned by HC, NH3 and N2O emission are also increase drastically.

•  It would be possible to recover the catalyst by high load engine operation to eliminate the HC.

•  This problem would be almost resolved in latest vehicles having DPF with active regeneration





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Relationship between total mileage and NOx emission

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0 50000 100000 150000 200000 250000 300000

in use condition after recovery

NO

x em

issi

on g

/kW

h

Total mileage km

JE05 test cycle Local bus with urea SCR

The more running distance, the much more NOx emissions - HC poisoning

Even with recovery operation, gradually increase・・・ In a case of pre-DOC replacement, NOx emission improved

Recovery operation





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Pre-DOC Deterioration •  From the fact that performance deteriorates with increasing of driving

distance, the possible cause is sulfur in fuel and oil. •  Sulfur in exhaust gas forms SO2 and flows into the catalyst, but SO2

has weak reactive. When SO2 is oxidized to SO3 on the catalyst, SO3 brings deterioration.

•  When the catalyst temperature is low, the reaction from SO2 to SO3 does not occur, but when it is high, some SO2 is not trapped on the catalyst, and it causes the deterioration at a certain temperature window.

•  The temperature window seems to be around 300℃, but this distribution is not used for durability test. At the point of validation, the same deterioration did not occur.

Ureatank

Dosingmodule

DOC1Engine

DOC2SCR

Ureainjection

NOx reductionNO→NO2

DOC: Diesel oxidation catalyst

Exhaust

NH3 slipreduction

Ureatank

Dosingmodule

DOC1Engine

DOC2

Ureainjection

NO→NO2

DOC: Diesel oxidation catalyst

Exhaust

NH3 slipreduction

SCR

NOx reduction

Pre-DOC





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Issues for the next durability test method

u  Existing durability test aimed to check whether vehicles could endure high temperature condition and rapid temperature change.

u  But, it cannot reproduce HC-poisoning in low temperature and

DOC deterioration caused by sulfur at about 300 ℃.

u  If including these conditions, test cycle will take longer time. It is not preferable.

u  New durability test procedure including this issue is now under

consideration.





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Assumed Issues in WHTC

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 500 1000 1500 2000

W HTC

JE05

Area reproduced at high-speed running in WHTC：Give priority to reduce emissions?

Area used at high-speed running in JE05： Give priority to decrease in the consumption of fuel or urea solution?

Engine speed　rpm

Eng

ine

torq

ue N

･m

Introduction of WHTC※

including cold start makes validation stricter. But vehicles for domestic use have gap between WHTC and real world. The gap causes troubles.

WHTC operation using a 302kW engine (target vehicle is GVW 25t class) JE05 mode operation using a vehicle meeting fuel efficiency standards with the same engine

Low-fuel consumption gives a tendency to use lower speed engine in real world. (Off-cycle test can solve some problems.) ※　WHTC: Transient cycle as the core cycle in WHDC





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Thank you for your kind attention

Contact to :

Hisakazu Suzuki

[email protected]

powertrain testing in japan · engines and powertrains technical workshop 1 powertrain testing in...

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