December 7, 2015 1



# Feasibility Assessment of Future Efficiency Improvement

for Class 8 Diesel Tractor Engines

EPA Ann Arbor, Michigan 

## Dr. Stephen J Charlton Independent Consultant December 7, 2015December 7, 2015 2 

# Outline

• Overview



## - Climate change



## - Innovation – A lot can happen in 12 years



## - HD Engine Greenhouse Gas Projections 

## • Summary – Findings and Recommendations • Technology and Product Development Roadmap



## - Demonstrated Performance



## - Key supplier engagement 

## • What can be achieved with existing engine platforms? • Impact of Engine technologies on the vehicle 

## • Reliability growth for advanced technologies • Determining more stringent standards • Concluding commentsDecember 7, 2015 3 

# Why am I here today? Climate Change 

# • Sea level rise: Global sea level rose about 17 centimeters (6.7 inches) in the last century. The rate in the last decade, however, is nearly double that of the last century. 

# • Warming oceans: The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of 0.302 degrees Fahrenheit since 1969. 

# • Shrinking ice sheets: The Greenland and Antarctic ice sheets have decreased in mass. Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006. 

# • Declining Arctic sea ice: Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades. 

# • Glacial retreat: Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa. 

# • Extreme events: The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. 

# • Ocean acidification: Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent. 

# • Decreased snow cover: Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier.December 7, 2015 4 

# Innovation – A lot can happen in 12 years

Google Self- Driving Car Tesla Model X Electric SUV Daimler Self- Driving Truck

2.5g NOx, 0.1g PM 0.2g NOx, 0.01g PM 92% NOx and 90% PM Reductions 2003 2015December 7, 2015 5 2010 SCR + DPF 

# Innovation – A lot can happen in 12 years

2002 Dual Leg NOx Adsorber 40 CFR Parts 69, 80, and 86 2010 Final Rule While other technologies exist that have the potential to provide significant emission reductions , such as selective catalytic reduction systems for NO X control, and development of these technologies is being pursued to varying degrees, we believe that the catalyzed diesel particulate trap and the NO X adsorber will be the only likely broadly applicable technology choice by the makers of engines and vehicles for the national fleet in this timeframe .

2017 - The EcoFit Single Module is 60% smaller and 40% lighter than current SCR DPF SystemsDecember 7, 2015 6 

## HD Engine Greenhouse Gas Projections

40.1% 41.4% 42.7% 43.4% 44.4% 44.6%

37% 39% 41% 43% 45% 47% 49% 51% 53% 55%

2009 2012 2015 2018 2021 2024 2027 2030 2033

HD Tractor Engine BTE% Progression SuperTruck Status June 2015 48% - 51.1% NAS Phase 1 Report 47.2% - 50.8%

GHG Phase 2

GHG Phase 1 SWRI Phase 2 Report 44.6% - 47.5% Engine Brake Thermal Efficiency [%]

Schedule Limit Standard [gCO2/HP- hr] Fuel Consumption

[Gallons/100 HP- hr] BTE [%] Step Change [%] 2010 Baseline 490 4.8134 40.1% Base 2014 Phase 1a 475 4.6660 41.4% 3.06% 2017 Phase 1b - Baseline for Phase 2 460 4.5189 42.7% 3.16% 2021 Phase 2 453 4.4499 43.4% 1.52% 2024 Phase 2 443 4.3517 44.4% 2.21% 2027 Phase 2 441 4.3320 44.6% 0.45%December 7, 2015 7 

# Determining the line haul engine standardsDecember 7, 2015 8 

# BSCO 2 

# Bridge

340 360 380 400 420 440 460 480 SET BSCO 2 Bridge 2017 - 2027 BSCO 2 – g/HP - hr 441 g/HP- hr 460 g/HP- hr 390 g/HP- hr NPRM SET BSCO 2 Bridge 2017 - 2027

Turbocompound Waste Heat Recovery Friction / Parasitics Aftertreatment DP Pumping – EGR etc. Combustion – FIE, CR Downsizing 1.3% 4.1% 1.0% 0.7% 0.8% 3 .0% 0.2% 2.6% 0.4% 1.1%

NOTE: All percentages are after the application of Adoption Rates and Dis -Synergy Factors – slide 31 2.6% 1.1% 4.2%December 7, 2015 9 

# Findings - 1 1. NAS Report on 21CTP / SuperTruck: “The engine systems Goal 1 of a 50% BTE for an emissions compliant engine has been achieved. Two of the four 

### SuperTruck teams have successfully demonstrated BTE greater than 50% in on -road tests using commercial, ultralow-sulfur diesel fuel”, 9.11.2015 

## 2. The NAS committee has shifted their focus to defining the pathways to a HD engine attaining 55% BTE. All programs are pursuing:

– Improved friction and pumping

– More effective air boosting systems

– Smaller auxiliary and accessory loads

– Waste heat recovery

– Low- temperature combustion 

## 3. The proposed rule contains very conservative standards for HD tractor engines equivalent to a 2.1% to 3.1% reduction in GHG emissions and fuel consumption for 2027 and beyond – when accounting for re -weighting of the steady-state test cycle.December 7, 2015 10 

# Findings - 2 4. WHR Technology is an important component of the technology package that can deliver a 15% or greater reduction of GHG emissions and fuel consumption by 2027 – NAS 21CTP Report, 9.11.2015 

## : “The 21CTP has successfully met Goal 1, to develop and demonstrate an emissions compliant diesel engine system for Class 7 and 8 highway trucks that achieves 50 percent brake thermal efficiency in an over- the-road cruise condition. The engine uses a waste heat recovery system ”. 

## 5. Advanced Combustion was eliminated from consideration ... “since the agencies do not anticipate these technologies will be commercially available by 2027” 

## Given the significant research effort on advanced combustion and the progress being demonstrated, the agencies should allow for incremental improvements being transferred from this work into products released in 2021, 2024 and 2027.December 7, 2015 11 

# Findings - 3 6. Downspeeding was included as a vehicle technology and allocated the CO 2 

## reduction to the vehicle via the GEM simulation. By so doing the stringency of the engine limit standard has been relaxed. This issue can be corrected by including downspeeding in the derivation of the proposed engine standards. 7. Even with the effective exclusion of WHR, advanced combustion and downspeeding, the 

## agencies failed to set aggressive technology forcing standards for the technologies it did include in its preferred package: Combustion / fuel injection optimization Exhaust aftertreatment (Lower DP) Engine friction and other parasitic losses Engine breathing system 

### Turbocharging system Engine downsizing 

### Volvo demonstrated 48% BTE without WHR compared with the proposed standard for HD tractor engines of 44.6% BTE (441 g/CO2/HP- hr). Cummins demonstrated 48.3% BTE without WHR.December 7, 2015 12 

# Findings - 4 8. The agencies should consider developing more accurate and current cost and retail price estimates based on a dialog with the SuperTruck OEMs and tier 1 supply base. Progress has been made between 2010 and 2015 both in simplifying designs for cost and reliability, and in better understanding manufacturing processes . 9. Attention should be paid to the progress being made by the SuperTruck teams to improve HD 

## tractor engine GHG emissions and fuel consumption. There is little evidence in the published reports from SWRI and the agencies of seeking data from the SuperTruck program – beyond citing the annual merit reviews as references.December 7, 2015 13 

# Findings - 5 10. By modifying the HD engine SET test cycle for GHG emissions and fuel consumption certification, the direct linkage between criteria pollutants and GHGs has been broken . 11. Synergistic and dis-synergistic effects need to be accounted for with the specific combinations of technology in mind. The agencies applied a 25% discount in 2021 and a 15% discount in 2024 and 2027 across all technologies .December 7, 2015 14 

# Recommendations – 1 1. The agencies should strengthen the standards for HD tractor engines used in line- haul and heavy- haul applications. These engines have the highest annual mileage, consume the most fuel and emit the most CO 2 

## . The following limit standards and schedule were found to be feasible in the time scale under discussion, and are recommended for consideration: MY 2027 and beyond HD Tractor Engines 390 gCO 2

### /HP- hr (50.4% BTE ) 

## 2. Retain the current phase - in schedule, while increasing stringency in 2021 and 2024 proportional with the final step proposed in bullet 1 above: MY 2024-2026 HD Tractor Engines 405 gCO2/HP- hr (48.5% BTE ) MY 2021-2023 HD Tractor Engines 435 gCO2/HP- hr (45.1% BTE )December 7, 2015 15 

# Recommendations – 2 3. If the agencies determine there is a need to manage risk associated with new technologies, they could consider a biennial review – as defined and implemented for the 2010 criteria pollutant program. 4. Downspeeding should be included in the derivation of the proposed engine standards. 5. The loss of alignment between criteria pollutant emissions with GHG emissions caused by proposed changes to the weighting factors for GHG emissions, could be remedied by either reverting back to the SET test cycle used for NOx and PM for GHG certification, or by adopting the new test cycle for NOx and PM certification.December 7, 2015 16 C
2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 A C B A C B A Technology Transfer Gov’t Co - Funded Programs, e.g. SuperTruck

Technology Development

B Key

A = Product Architecture and Design B = Product Validation / Reliability Growth C = Mfg. Process / Supply Chain Readiness = Product Launch

Product Development 

# Engine Product Development Cycles 2015 - 2027

• Three technology and product development cycles before 2027 

## launch • Ample opportunity for Technology Reviews by the agencies • OEMs are engaged – DOE programs 

## and GHG Phase 1 • Supply base is engaged in the development of advanced technologies:

- WHR – heat exchangers, expanders and 

### working fluids



## - Reduced friction – bearings, pistons, liners, var. flow pumps and low vis. lubricants Phase/Gate Process for Technology and Product DevelopmentDecember 7, 2015 17

Oil Viscosity 

# Key Engine Technologies
Advanced Combustion Variable Valve Actuation Low Temperature Combustion PCCI RCCI

Dual Fuel Peak Cylinder Pressure Advanced Sensors Advanced Fuel Injection
Optimized Lube and Cooling Variable Flow Lube & Coolant Pumps Engine Friction & Parasitic Losses
ORC/WHR Ethanol, R245fa
Engine Pumping Losses EGR Delivery

Delta P LP & HP EGR Turbocompound Mechanical / Electric High Efficiency VGT Downspeeding 1000 RPM Cruise Downsizing

11L High BMEP High PCP Air Handling

2-Stage, VGT Aftertreatment Back Pressure DPF Passive Regeneration SCR Efficiency

High EngineOut NOx NH3 Slip

Catalyst Performance Passive NOx Adsorber Piston, Rings, Liner & Bearings Reduced Friction Seals Fuel System Parasitics High CR - Chamber Design / CFD

ORC/WHR Mech./Elec. ORC/WHR Turbine, Scroll, Piston eTurbo,

Asymmetric Actively

Controlled Air CompressorVariable

Speed Cooling Fan

Electrically Driven Components Reduced Swirl, Quiescent

Advanced Sensors Model - Based Controls Adaptive

Real -Time FE OptimizationDecember 7, 2015 18 

# Downspeeding (and steady-state test cycle changes)

• Proposed changes to the SET weighting factors reflect the trend toward 

## downspeeding • The change also reduces the stringency of the standards – since the 2017 baseline was determined using the current SET weighting factors • With no change in engine design or calibration, the new weighting factors reduce the SET composite BSCO 2 

## by 1 - 2% • Should be accounted for in the engine standards A B C 25 0 5 0 75 100

12% 9% 9%

12% 12%

12% 9% 10% 10% 2%

1 % 1 % 1 % Engine Load [%]

Engine Speed [%] 100 50 75 0 15% 5%

A B C 25 0 5 0 75 5% 5% 5%

5% 5% 10% 10% 10% 8% 8% 9% Engine Load [%]

Engine Speed [%] 100 50 75 0 23% 39% 23% A, B , C speed weighting = 45% 38% 5% A, B , C speed weighting =

European ESC steady-state test with time weighting factors – Adopted by EPA in 2000 for criteria pollutants, and in 2014 for GHG emissions

from HD tractor engines Proposed time weighting factors for Phase 2 GHG and fuel consumption standards, for HD tractor engines – with major shift to the A speed. 100December 7, 2015 19 

# Downspeeding and Steady-state test cycle changes

• HD engines can be optimized for downspeeding:

- Reduce torque peak speed



## - Reduce rated speed



## - Increase maximum torque



## - Optimize air handling and combustion for improved fuel consumption



## - Increase peak cylinder pressure 

# • This Chalmers / Volvo study yielded a 3.4% reduction of fuel consumption and CO 2 

# • SWRI study yielded a 2 -4% reduction 

# • These reductions are in addition to the reductions due to changes in SET weighting factors of 1 - 2% 

# • Combined reduction of between 3% and 6% should 

## be included in the BSCO 2 

## engine standards Source – Chalmers / Volvo, Narayanan - 2011 -3% 500 1000 1500 2000 3200 3000 2750 2500 2250 2000 1750 1500 1250 1000 Engine Speed [r/min] Torque [Nm] Typical EURO 6 / US 2010 Torque Curve

Highway Cruise Speed Torque Curve Optimized for Downspeeding Highway Cruise Speed

0%

- 1%

- 2%

-4%

-5%

- 6% +1% 3.4% Reduction of CO 2 Customer Duty - Cycle Change in BSFCDecember 7, 2015 20 

# Downspeeding and Steady-state test cycle changes

• Sweet spot is moved to lower engine speeds • Improvements in fuel consumption with lower 

## operating speeds are due to:

- Heat transfer – strong function of engine / piston speed



## - Shorter heat release duration in crank angle / centroid



## - Friction reduction – cylinder kit, overhead, bearings 

## • Fuel consumption reduced significantly at lower speed
• This reduction of fuel consumption and CO 2 

## will be realized on the SET engine test

Source – Chalmers / Volvo, Narayanan - 2011 -3% 500 1000 1500 2000 3200 3000 2750 2500 2250 2000 1750 1500 1250 1000 Engine Speed [r/min] Torque [Nm] Typical EURO 6 / US 2010 Torque Curve

Highway Cruise Speed Torque Curve Optimized for Downspeeding Highway Cruise Speed

0%

- 1%

- 2%

-4%

-5%

- 6% +1% 3.4% Reduction of CO 2 Customer Duty - Cycle Change in BSFCDecember 7, 2015 21 

# Waste Heat Recovery

• Many options under active development:

- Working fluid – Ethanol, R245fa, Toluene ...



## - Expander – turbine, scroll, piston ...



## - Heat sources – EGR, Exhaust, CAC, Coolant



## - Recuperator 

## • Supply base actively engaged and developing technology and products
• Small offset in weight and heat rejection
• Demonstrated CO 2 

## reductions of 4- 6% in line haul application EGR Heat Exchanger

Recuperator Turbine

Condenser Exhaust Heat Exchanger SCR / DPFDecember 7, 2015 22



### EGR heat source only – 3-4% CO 2 

### reduction 

# Waste Heat Recovery – Not one size fits all

Exhaust and EGR heat source – 4-6% CO 2 

### reductionDecember 7, 2015 23 

# WHR - Tier 1 Suppliers Engaged and Investing Resources Significant engagement by the supply base: • Bosch • Mahle / Behr / Amovis • Cummins Turbo Technologies • Modine • Voith • Barber Nichols • ...December 7, 2015 24 

# WHR - Tier 1 Suppliers Engaged and Investing Resources

Cummins Turbo Technologies – Axial turbine expander for Waste Heat Recovery with mechanical drive May 2015 - Mahle Group has acquired Amovis GmbH – specifically to gain access to Organic Rankine Cycle technology for commercial vehicles . Mahle portfolio now includes all of the

essential technologies for a complete ORC system

Modine is developing a series of compact heat exchangers designed to capture waste heat from the exhaust stream of a diesel engine and convert this heat into useful power to improve engine efficiency and reduce CO2 emissionsDecember 7, 2015 25 

# WHR - Tier 1 Suppliers Engaged and Investing Resources Honeywell – Developing working fluids for Organic Rankine Cycles, with low GWP. 

### Genetron 245fa has the most favorable properties for low temperature heat recovery systems. Its thermodynamic properties are different than HFCs typically used in refrigeration.December 7, 2015 26 

# Impact of WHR on the vehicle

• Space claim has been demonstrated in real world operations in SuperTruck projects 

### • Condenser integrated within the cooling module

• Space claim and weight offset by improvements to existing aftertreatment 

### modules EGR Heat Exchanger

Recuperator Turbine

Condenser Exhaust Heat Exchanger SCR / DPF 

### The EcoFit Single Module is 60% smaller and 40% lighter 

### than current SCR DPF SystemsDecember 7, 2015 27 

# Advanced Combustion and Tools / 55% BTE

• CFD tools are a very effective way to search the available design space 

## • Design space is large:

- Spark- ignition, compression ignition



## - Stoichiometric, lean, ultra - lean stratified



## - Fuel properties:  Diesel, gasoline, natural gas, ethanol ...



## - Chamber geometry and compression ratio



## - Injection parameters:  Gasoline PFI, GDI  High pressure diesel injection >3000 bar  Nozzle configuration, multi - pulse



## - Charge motion – swirl, tumble



## - Turbulence generation



## - Advanced sensors – cylinder pressure ... CFD used to optimize combustion chamber geometry and CR for GISFC – 0.5% BTE
Dual Fuel AFCI Diesel Premix Conventional Diesel Quantity of Alternate Fuel Premix Fuel Quantity

100% 0% 0% 100%

Diesel LTC

Diesel PCCI Dual Fuel

H CCI Conventional Dual Fuel Single

Alternate Fuel HCCI Compression IgnitionDecember 7, 2015 28 

# Engine Platform Implications

• The Mission – Interstate truck load and less than truck load , all terrain, all altitudes

- LTL productivity demands performance 425 -450 HP, 1650- 1850 ft- lbs



## - TL premium / heavy operations demand 450- 550HP , 1850- 2050 ft- lbs



## - 10- 12 MPG 

## • Downsizing to 11L – significantly increases the BMEP required to meet the mission – increased PCP, bearings etc. • Downspeeding further increases the demands for high BMEP • Waste heat recovery does not put demand on the engine platform
• 15L engines can achieve the mission without major redesign • 13L engines may need significant upgrade 

## • 11L platform would require major redesign or clean sheet designDecember 7, 2015 29 

# Reliability Growth

• 12 years is time enough to develop reliable products with 50% BTE 

## • Key technologies are understood and ready for product development • All OEMs and engine manufacturers run extensive field testing in customer operations



# - Typically 5 - 10M miles per launch 

## • Tier 1 supply base development of technology



# - Bosch, Mahle, Modine, Cummins Turbo ... 

## • Learnings from earlier emissions and OBD programs – EGR, SCR, DPF • Early collaboration is critical – vehicle integration, supply base readiness ... • Analysis tools are highly capable – CFD, FEA • Service organizations engaged early • Telematics, remote diagnosticsDecember 7, 2015 30 

# SuperTruck Demonstrated Performance – Cummins and DaimlerDecember 7, 2015 31 

# SuperTruck Demonstrated Performance – Volvo and NavistarDecember 7, 2015 32 

# Derivation of the Proposed Engine StandardsDecember 7, 2015 33 

# BSCO 2 

# Bridge

340 360 380 400 420 440 460 480 SET BSCO 2 Bridge 2017 - 2027 BSCO 2 – g/HP - hr 441 g/HP- hr 460 g/HP- hr 390 g/HP- hr NPRM SET BSCO 2 Bridge 2017 - 2027

Turbocompound Waste Heat Recovery Friction / Parasitics Aftertreatment DP Pumping – EGR etc. Combustion – FIE, CR Downsizing 1.3% 4.1% 1.0% 0.7% 0.8% 3 .0% 0.2% 2.6% 0.4% 1.1%

NOTE: All percentages are after the application of Adoption Rates and Dis -Synergy Factors – slide 31 2.6% 1.1% 4.2%December 7, 2015 34 

# Concluding Remarks – 1

• More stringent line - haul engine standards are feasible in 2027 timeframe

– 15% reduction of CO 2

### , BSCO 2 

### = 390 g/HP- hr



### – Essential for fuel economy > 10- 12 MPG

– A combination of SET relaxation and downspeeding will almost meet the proposed 2027 standard – however – neither were accounted for in the determination of the standard


## • Industry has proven track record of innovation

– Regulation is essential to drive investments in research and development

– 12 year lead time + 5 years of DoE SuperTruck programs

– Consider conducting a biennial review as was done for the 2007/2010 HD criteria pollutant rule

– Supply base is engaged and developing technology and productsDecember 7, 2015 35 

# Concluding Remarks – 2

• Meeting these standards will not require the development of clean sheet engine platforms – in the 13 - 15L class
• Downsizing to 11L for LTL and TL applications is a non -starter:

– Minimal CO 2 

### reduction

– Clean sheet engine design, major capital and development expenses


## • Waste heat recovery is an important technology for fuel consumption and CO 2 

## reduction:

– EGR heat source provides 3 -4% CO 2 

### savings

– EGR and exhaust heat source provides 4- 6% savings

– Industry working toward 2 year payback