Breakthrough made in energy efficiency, use of waste heat

Apr 01, 2009

Engineers at Oregon State University have made a major new advance in taking waste heat and using it to run a cooling system - a technology that can improve the energy efficiency of diesel engines, and perhaps some day will appear in automobiles, homes and industry.

This heat-actuated cooling system, which will probably find its first applications by the U.S. Army, could ultimately be applied to automobiles, factories or other places where waste heat is being generated, and used to provide either or electricity.

In its first military application where stationary diesel generator sets are used, researchers say they expect improved efficiencies of 20-30 percent in situations where cooling is needed.

The system is one of the early applications of microchannel technology that is being developed jointly by OSU and the Pacific Northwest National Laboratory, through a joint venture called the Microproducts Breakthrough Institute.

"Our approach will provide a capability that has not yet been achieved for efficiently using waste heat with small-scale systems," said Richard Peterson, a professor of mechanical engineering at OSU. "The technology has been successfully developed and we should have a working prototype ready for demonstration by this summer."

Conceptually, the system works somewhat like existing heat pumps, but it's powered by waste heat, not electricity. What makes the technology unique is the use of microchannel components and an efficient "vapor expander" to provide high heat transfer rates and smaller, lighter and more efficient heat exchangers.

"Right now, about 75 percent of the fuel energy in most stationary diesel generators used to produce electricity is lost in the form of waste heat," Peterson said. "And the military often needs these generators to operate air conditioning for advanced electronic equipment and other applications. So we're using that waste exhaust heat to drive an expander-compressor cycle that provides cooling."

The first prototype will be a small five-kilowatt cooling system that's a little larger than an automobile air conditioner in capacity, Peterson said. It's the type of air conditioner, for instance, that could be used in a forward-deployed military command post. The military is particularly interested in the system and has supported its development, he said, to help improve fuel efficiency and economy.

For a complete range of commercial or consumer applications, some further size improvements, component integration and reduced cost will be needed, researchers say. But the potential applications are broad.

The most immediate and obvious, of course, might be automotive air conditioning, where heat energy that's now being blown out the tailpipe might be used to power the car's air conditioning. The integration of a generator into this technology might allow it to also produce electricity instead of air conditioning, depending on what was needed.

Industrial applications to improve are clearly possible - basically, anywhere significant amounts of heat are being produced but not used. While the early applications may be most readily developed with waste heat, it could also be possible to use this technology with heat that's intentionally produced, such as with moderately concentrated solar energy to provide a building's air conditioning on hot, sunny days.

"Since this technology would allow you to produce electricity or cooling whenever something is hot, it might be an ideal complement to a 'smart' energy system that could provide extra power during peak demand periods," Peterson said. "We can now take heat and use it to create either electrical power, heat or cooling. It's not yet clear what all the possible applications will be."

OSU, through the Microproducts Breakthrough Institute, can already produce the microchannel devices needed to make this system operational, but work will continue in order to develop improved manufacturing efficiencies and create less expensive devices at higher production volumes.

Source: Oregon State University (news : web)

Explore further: 3-D printing leads to another advance in make-it-yourself lab equipment

add to favorites email to friend print save as pdf

Related Stories

Keeping cool using the summer heat

Jan 23, 2009

(PhysOrg.com) -- While most Australians are taking care to shield themselves from the harsh summer heat, scientists from the CSIRO Energy Transformed Flagship are working on ways to harness the sun’s warmth ...

NIST helps heat pumps 'go with the flow' to boost output

Jan 23, 2008

Air-source heat pumps typically deliver 1 1/2 to three times more heating energy to a home than the electric energy they consume. This is possible because heat pumps move heat rather than convert it from a ...

A carbon-neutral way to power your home

Nov 27, 2008

(PhysOrg.com) -- A super-efficient system that has the potential to power, heat and cool homes across the UK is being developed at Newcastle University.

Discovery Captures, Converts Heat

Apr 06, 2005

Your car's engine loses 70 percent of its energy as waste heat-but Australian and Oregon scientists may have figured out an efficient way not only to recover that lost energy, but to at long last capture the power-producing ...

A greener way to power cars

Feb 20, 2008

Cardiff University researchers are exploring how waste heat from car exhausts could provide a new greener power supply for vehicles.

Recommended for you

Nanoscience makes your wine better

6 hours ago

One sip of a perfectly poured glass of wine leads to an explosion of flavours in your mouth. Researchers at Aarhus University, Denmark, have now developed a nanosensor that can mimic what happens in your ...

Fly ash builds green cement mixture

6 hours ago

An eco-friendly cement, known as Alkali Pozzolan Cement (APC), containing a mixture of fly ash, dry lime powder and sodium sulphate under specific scaffolding conditions has been developed by Curtin University ...

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

TheEyeofTheBeholder
1 / 5 (1) Apr 01, 2009
Come on now, we already have propane refrigerators and solar heat AC units, they are only now saing we could have been using this units in our cars? They better hurry up and produce them before we have all electric cars, everywhere! This could help lighten the load on cars.

By the way, does any one know the temperature of the heat that makes a propane refrigerator work? I do not own one so I can not to the measurement myself.
Nik_2213
1 / 5 (1) Apr 01, 2009
Sounds like the ammonia-evaporating fridge cycle that Einstein helped patent...
NeilFarbstein
1 / 5 (1) Apr 02, 2009
I thought he invented a magnetic cooling refrigerator.
VOR
not rated yet Apr 04, 2009
electric car's batteries make a lot of heat too.