With the poor global economy, consumers are looking for ways to maximize their money and saving on gasoline is one way to do that. At the same time, the U.S. is investing heavily in methods that will help reduce the U.S. dependence on foreign oil.
One of the ways that automakers are looking to help increase fuel economy, simultaneously reducing the need for oil and lowering the cost for fuel to consumers, are hybrid and electric vehicles. The biggest problem facing hybrid vehicles --like the Toyota Prius -- is that they cost much more than a comparable normal vehicle and the batteries needed are heavy and expensive to replace.
A group of German researchers and engineers are working on a new hybrid powertrain that uses compressed air rather than electric batteries to boost the efficiency of an internal combustion engine. Lino Guzzella, a Professor of Thermotronics, says that today's hybrid vehicles are too expensive to be used in developing nations like China and India.
Guzzella and his team are currently researching a pneumatic hybrid system that is simpler to build and cheaper than electric hybrid systems available today. Guzzella said, "The apple must be ripe but still hang just low enough to stay within reach."
The power plant concept that Guzzella is working on uses a compressed air tank connected to an engine rather than an electric battery. When the engine moves a vehicle from a stop or shifts gears the pneumatic hybrid system pumps compressed air into the engine through electronically controlled valves.
When fuel is added to the compressed air, the engine is able to respond quickly. The compressed air system allows the engine itself to be downsized from the common four-cylinder size to only two cylinders. Exact power figures for the engine aren’t offered, but Guzzella points out that your typical engine needs only 30 HP for normal driving conditions. To increase performance, the prototype engine uses a turbocharger.
The researchers point out that the pneumatic system isn’t as efficient as an electric hybrid system, but the pneumatic system does offer 80% of an electric hybrid’s efficiency. The big benefit of the pneumatic system is a significantly reduced cost to build and purchase compared to electric hybrid systems.
The engine, currently in testing on a test bench system, is capable of capturing compressed air from the engine during deceleration. The additional cost for adding a pneumatic hybrid powertrain to a vehicle is estimated to be only 10%. Additional costs for adding an electric hybrid system to a vehicle are estimated to be around 200%.
Guzzella and his team have already patented several of the ideas used in the hybrid system. According to the researchers there are already several engine makers and automotive suppliers interested in the pneumatic hybrid engine.
Despite the interest, launching a new power plant system in the current global economy may prove a very difficult challenge. Guzzella says he still thinks that people will find his pneumatic hybrid system interesting. He predicts that over the next 20 years technology on the horizon could replace the internal combustion engine.
