Award-winning device recovers energy from railroad vibrations
Friday November 30, 2012, by Bernard Neumeister
Much of the mechanical energy in abundance around us is irregular and oscillatory and can be a bit difficult to harness effectively. Typical energy recovery systems tend to be designed for low-power applications in the milliwatt range, but researchers at Stony Book University in New York have developed a new patent-pending electromagnetic energy recuperator capable of '' use the vibrations of a locomotive traveling on a track section to supply signaling lights, works surveillance systems or even monitor switches.
When a train is running on the track, the load it exerts on the track causes a vertical deviation. This displacement could give rise to a regeneration device such as an electromagnetic recuperator and generate enough power to operate local railway applications, which is particularly useful in remote areas where electrification is not profitable. Recovering such energy is much more efficient with regular, unidirectional movement, but the vibrations caused by the track of a moving train are of the pulse, bidirectional and somewhat erratic type.
Professor Lei Zuo and graduate students from the University's Mechanical Engineering department Gopinath Reddy Penamalli, Teng Lin and John Wang say they have designed a new recuperator capable of converting irregular and oscillating vibrations of railway tracks into one regulated unidirectional rotational movement, similar to how a voltage rectifier converts alternating current into direct current.
“The United States has the longest railroad tracks in the world, at around 225 km, which are often in remote areas,” Professor Zuo said. "It is very important but also very expensive to supply the electrical infrastructure on the sides of the track such as traffic lights, crossings, switches and surveillance sensors. Our invention (the rectifier of mechanical movements based on the railroad track energy recuperator) can harness 000 watts of electrical energy from train-induced track deviations to power track-side electrical equipment. Using two one-way clutches, the innovative rectifier of mechanical motion converts the irregular vibrating movement up and down, into a unidirectional rotation of the generator, thus breaking the fundamental challenge of recovering vibrational energy and providing significant advantages in terms of high efficiency and high reliability "
Impact forces from repeated loading / unloading should also be reduced by incorporating a flywheel to stabilize the generator. According to Professor Zuo, the technology allows the generator to rotate in one direction with a constant speed in an area where the speed is more efficient, and modifies the negative influence of inertia in a positive movement, which reduces mechanical stresses and increases the reliability of the system. Prototype bench tests resulted in a mechanical efficiency of between 55 and 72%.
"Such a design not only avoids the problems of friction and shock induced by the oscillation movement, but also allows us to take full advantage of the pulse-like functionality of the track to recover more energy" -he.
Professor Zuo estimates that implementing such a device could save more than $ 10 million in track supply costs for New York State, with a reduction of 3.000 tonnes of carbon dioxide each year.
"If 10.000 units of 200-watt recuperators were deployed in New York state with a 20% duty cycle, the energy benefits would be 400.000 watts, or 3,5 x 10 ^ 6 kWh per year." , he explained. "With an average price of $ 0,14 per kWh of electricity for the transportation sector, that annual electricity savings will be half a million dollars for their state of New York alone."
The team was honored with "The Best Application of Energy Harvesting" at the "3rd Energy Harvesting and Wireless Sensor Networks USA" awards ceremony, which was held in Washington on November 7 - 8, and has already licensed its technology to Electric Truck / Harvest NRG for commercialization.
sources: http://www.infohightech.com/spip.php?article32313
et http://commcgi.cc.stonybrook.edu/am2/pu ... ions.shtml
It will certainly be profitable where the tracks are not electrified ... otherwise it will certainly be like solar PV ...
