Whats New in Engine Research Whats New in Engine Research Mark - - PowerPoint PPT Presentation

Mark Musculus

Engine Combustion Department Combustion Research Facility Sandia National Laboratories, Livermore, Ca Funded by U.S. Department of Energy Program Managers: Gurpreet Singh and Kevin Stork SoCal Science Café, Newport Beach, CA April 7, 2007

What’s New in Engine Research What’s New in Engine Research

Energy and Oil in the U.S. Energy and Oil in the U.S.

Total U.S. energy from oil (%):…………….. ___% 40 96 U.S. transportation energy from oil:……….. ___% Infrastructure U.S. imported oil in 1973:…………………… ___% 36 Oil price increase in 1973 embargo:………. _____% +350 U.S. imported oil in 2005:…………………… ___% 66 Imported oil share of U.S. trade deficit:…… ___% 30 CO2 increase from 0 AD to 1800 AD:.......... _____% near 0 CO2 increase from 1800 AD to 1900 AD:.... __% 4 CO2 increase from 1900 AD to 2000 AD:.... ___% 25 Economics National Security Climate Change Air Pollution Stage 1 smog alert days in L.A.,1975:......... ____ 118 Stage 1 smog alert days in L.A., 2000:........ ___

Reducing Oil Problems through Engine Efficiency Reducing Oil Problems through Engine Efficiency

U.S. Department of Energy goal for engine fuel-efficiency improvement is 50% increase. This would reduce oil usage by 4 Million Barrels / Day (out of 20), which is equivalent to: Infrastructure Economics Nat’l Security Climate Air Pollution 30% reduction of oil usage for transportation 12% reduction of our trade deficit 30% reduction of our oil imports Turn back the clock on CO2 emissions by 10 years The challenge is to improve efficiency while continuing to improve air quality

Engine Efficiency Depends on Compression Ratio Engine Efficiency Depends on Compression Ratio

• The combustion chamber is

above the piston, where the fuel burns.

• The compression ratio (R) is the

maximum combustion chamber volume divided by the minimum combustion chamber volume:

• R = V1 / V2
• Higher compression ratios have higher efficiencies.

So, one BIG way to increase engine efficiency is to increase the compression ratio.

• Most engines have 4, 6, or 8

cylinders, each with a piston that goes up and down.

– For 87 octane gas, max. compression ratio = 9. – With higher octane premium, we could use higher

compression ratios, but …

n In a gasoline engine, fuel is mixed

with air before

So Why Don’t They Just … Increase the Compression Ratio? So Why Don’t They Just … Increase the Compression Ratio?

compression.

n The fuel must burn only when ignited

by the spark plug, at the proper time.

n Higher compression = higher temperature. n Too high compression ratios can ignite

fuel before the spark, reducing efficiency and causing … that is very expensive!

n So, compression ratio must stay low if the fuel

is mixed with air BEFORE compression. explosive combustion (knock).

So Why Don’t They Just … Mix in the Fuel AFTER Compression? So Why Don’t They Just … Mix in the Fuel AFTER Compression?

n They do, in a Diesel engine! Fuel is injected after compression,

so the fuel cannot burn too soon!

n Diesel compression ratios = 16-22, so efficiency is much higher. n Problems: (1) high temperatures and (2) poor fuel-air mixing cause

much higher air pollution than gasoline engines.

n But wait, gasoline engines also have

high temperatures, yet they have low air pollution!

– Q: Why? – A: Better fuel-air mixing and …

THREE-WAY CATALYTIC CONVERTERS!

So Why Don’t They Just … Put 3-Way Catalytic Converters on Diesel Engines? So Why Don’t They Just … Put 3-Way Catalytic Converters on Diesel Engines?

n

3-way catalytic converters only work when fuel and air are balanced, with just enough oxygen in the air to burn with the fuel.

n

In a diesel, fuel doesn’t have enough time to completely mix with all of the air, so some extra air is always left over.

n

We do not yet have such a simple 3-way catalytic converter that works as efficiently with left-over air, though it is being researched.

n

So, currently, our choices are: 1.Clean gasoline engine, but low compression ratio, so low efficiency.

• 2. Efficient diesel engine, but

polluting from poor mixing and no catalytic converter.

To control either of these new engines and achieve high efficiency with low pollution, we need to understand how fuel mixes with air, ignites, and burns inside the engine.

So Why Don’t They Just … Design a New Kind of Engine? So Why Don’t They Just … Design a New Kind of Engine?

n

They do! In collaboration with the U.S. automotive industry, Sandia National Laboratories is researching two new engines:

• 1. “Homogeneous Charge Compression Ignition (HCCI)”

(gasoline engine with high compression ratio)

Add more air so fuel won’t ignite too soon at high compression ratio, remove spark plug (!), & ignite fuel by compression (more like diesel)

• 2. “Low-Temperature Combustion Diesel (LTC-Diesel)”

(diesel engine with lower temperatures and better mixing)

Use exhaust-gas recirculation (EGR) to reduce temperature, and inject fuel during compression for better mixing (more like gasoline)

n Our goal is to provide the fundamental

science-base for engine combustion.

Engine Research at Sandia National Laboratories Engine Research at Sandia National Laboratories

n We use specially modified engines

with high-strength windows to view fuel mixing with air, ignition, combustion, and pollutant formation inside the engine using lasers and high-speed cameras.

n Strong interaction and

collaboration with universities, industry, and other national labs.

Diesel Combustion Movie Diesel Combustion Movie

Eight-hole fuel injector squirting out jets of fuel that burn inside the engine

Advancing the Science-Base of Combustion Using Laser and Optical Diagnostics Advancing the Science-Base of Combustion Using Laser and Optical Diagnostics

* Based on research of John Dec, Sandia National Laboratories

HCCI Engine Combustion Movie HCCI Engine Combustion Movie

Distributions of fuel and temperature inside the engine cause different regions to ignite at different times

* Data courtesy of John Dec, Sandia National Laboratories

Impact of Engine Research at Sandia National Laboratories Impact of Engine Research at Sandia National Laboratories

n Cummins designed their 2007 low-

emissions LTC-Diesel engine using computer modeling and analysis.

ISB (6.7 liter diesel)

Figure Courtesy of Cummins Inc.

n In February 2007, GM announced new demonstration HCCI

engine with up to 50% greater fuel efficiency.

–Not ready for market yet, but prospects are promising.

n Much work to be done - the science-base for high-efficiency

low-emissions engines is still needed to aid development.

– After-the-fact testing only. – Significantly reduced development

time and cost.

– Computer models could only be

formed using the science-base of diesel combustion fundamentals.

Concluding Remarks Concluding Remarks

n Engine efficiency improvements are important for both

stand-alone engines and electric hybrid vehicles.

n A major challenge is that fuels in the market are changing at

the same time as engines – a “Dual Revolution.”

–Bio-fuels, tar sands, oil shale, gas/coal to liquids, hydrogen, etc. –New engines will need to be compatible with many fuels.

n A renewable, clean liquid hydrocarbon future is possible. n Sandia National Laboratories research

includes fuels, combustion, computer modeling, and much more!

n Facility built in 1980 n 100 full-time employees n 100 visitors per year

– Post-docs – University faculty – Undergraduate interns – Graduate students – Industrial collaborators

Combustion Research Facility Sandia National Labs, Livermore, California Combustion Research Facility Sandia National Labs, Livermore, California

"The mission of the CRF is to conduct a broad range of basic and applied research and development in combustion science and technology. We aim to improve our nation's ability to utilize and control combustion processes." Visitors bring technical knowledge and skills. The CRF provides access to facility equipment, resources, and a knowledge base of combustion http:/ / www.c a.sandia.go v/ c rf/ re se arc h/ inde x.php

• r Go o gle “Co mbustio n Re se arc h F

ac ility”

Conclusion and Invitation Conclusion and Invitation

n

This presentation provided only a tiny glimpse of the breadth of activities at Sandia National Laboratories, both in engines and in

• ther research and development.

n

If you are interested in learning more, visiting, or working at the Sandia National Laboratories, talk to me or visit online: http://www.ca.sandia.gov/crf/research/index.php

• r Google “Sandia National Laboratories”
• r Google “Combustion Research Facility”

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