Nanofluids Could Make Cool Work of Hot Truck Engines

What the work is about

Truck engines are hot places, and new emission reduction technologies such as exhaust gas recirculation (EGR) can make them even hotter. The coolants, lubricants, oils, and other heat transfer fluids used in today's conventional truck thermal systems (including radiators, engines, and HVAC equipment) have inherently poor heat transfer properties. And conventional working fluids that contain millimeter- or micrometer-sized particles do not work with newly emerging "miniaturized" technologies because they can clog in microchannels.

Argonne National Laboratory has developed metal nanofluids that can dramatically enhance the thermal conductivity of conventional heat transfer fluids and flow smoothly in microchannel passages. These "nanocoolants," as they're known, can enhance heat transfer more than several times better than the best competing fluid.

How it can be used

Because engine coolants (ethylene glycol/water mixtures), engine oils, automatic transmission fluids, and other synthetic high-temperature heat transfer fluids currently possess inherently poor heat transfer capabilities, they could benefit from the high thermal conductivity offered by nanofluids. Engines designed to take advantage of nanofluids' cooling properties would be able to run at more optimal temperatures. Nanofluids would allow for smaller, lighter radiators, pumps, and other components. Vehicles that weigh less could travel further on the same amount of fuel (i.e., get more miles per gallon). More energy-efficient vehicles would save consumers money. Moreover, burning less fuel would result in fewer emissions and a cleaner environment.

What makes it unique

• Ultra-high thermal conductivity
• Long-term stability
• No dispersants required to keep nanoparticles in suspension
• Extremely small particles do not clog channels
• Usable in existing applications such as radiators, HVAC, and electronics

February 11, 2005