Exhaust Pipe Electricity for Engine Efficiency

May 4, 2009 – Vol.14 No.7

EXHAUST PIPE ELECTRICITY FOR ENGINE EFFICIENCY.
by Bruce Mulliken, Green Energy News

Thin Gap Automotive of Ventura, California, has a noteworthy idea to improve the fuel efficiency of conventional cars, even hybrids: Use the hot expanding exhaust gases of a vehicle’s internal combustion engine to spin a turbine to drive an electric generator. The company, a spin-off of Thin Gap, a maker of high-tech, small electric motors calls it the Turbo Generator.

The internal combustion engine is an incredibly inefficient device. More than 60 percent of the energy content of gasoline is wasted through internal engine friction or is expelled as waste heat through the engine’s cooling system and exhaust. Of the heat energy lost 40 percent goes out the tailpipe. Internal combustion engines rely on heat to expand gases to force pistons through cylinders and turn the crankshaft, yet much of the heat energy created in the explosion of gasoline (or diesel fuel) is dissipated into the air one way or another. That’s not too good. Internal combustion engines are heat engines yet throw away most of the heat they make. That’s not a very efficient use of fuel and a declineing resource.

Over the hundred-plus years of development, cars have become easier to drive and more comfortable. All of those creature comforts – either hydraulic or electrically powered – need energy stored in the gas tank. For instance, a car’s air conditioning system needs the engine to run – burning fuel – to operate. Fuel economy is usually better in cooler months when A/C isn’t needed. Power steering in hydraulic form uses up power directly in the same way as air conditioning, via a belt driven off the engine. Newer electric power steering – developed to save fuel – uses fuel to generate electricity to energize the system. Turn the heated seats on? Some small additional amount of fuel is needed to keep your backside warm. Like to keep the vehicle’s sound system revved-up?. Yep, the car will burn more fuel, even though the amount is undetectable. Most systems in cars, the horn, the lights, the power seats all use a little bit of petroleum in order to operate. (The heater, by the way, uses very little energy, only the fan. Instead of engine heat being wasted into the atmosphere it’s used to keep the vehicle’s occupants warm.)

Thin Gap Automotive thinks waste gases, wasted heat, going out the tailpipe should be put to work generating power to run the ancillary equipment in a car, truck or SUV. If exhaust gases were put to work, vehicles utilizing the Turbo Generator would get better fuel economy. Exactly how much would take some testing, but the company says its device would directly increase vehicle fuel economy by a variety of methods, including:

--- Supplying electric power to the vehicle’s electrical system, allowing for use of smaller alternators or no alternators;

--- Driving engine accessories electrically that are currently crankshaft driven (e.g. water pump, power steering pump and air conditioning compressor) without increasing the alternator size;

--- Directly driving the flywheel motor of semi-hybrid vehicles and;

--- Supplementing the energy supply to the battery system of full hybrid vehicles, thereby reducing the required on-time for the internal combustion engine.

For manufacturers the inclusion of a Turbo Generator would be an assembly line bolt-in-place energy saver. It would be a new component under the hood for sure, but one that could eliminate other components such as replacing the water pump with its belt drive system with an electric pump.

Aside from the pressures of company survival, car companies are now also under pressure to meet the new U.S. Corporate Average Fuel Economy (CAFE) regulation that requires a 40 percent increase in fuel economy. Thin Gap’s plug-and-play device could help them meet the new regulation.

ThinGap’s motors and generator technology replaces the iron core/laminations and wire windings used by conventional motors with a precision thin copper sheet. According to the company, the motors provide higher power-to-weight ratios, a wider range of speed and torque capabilities, improved heat dissipation and lower electrical resistance. The same technology would be applied to the Turbo Generator. (4/29/09)

Links:

ThinGap Automotive
http://www.thingapautomotive.com

ThinGap
http://www.thingap.com

--- Harnessing Heat for Work.