Ian Briggs
IT seems a paradox that dirty exhaust gases could help to make vehicles cleaner but the notion might soon be true thanks to a team of Yorkshire boffins.
Members of the University of Sheffield's Electrical Machines and Drives Group and expert engineers from Harrogate-based Switched Reluctance Drives have helped to develop a way of recovering energy that would normally be lost down the exhaust pipe.
The team, which has been joined by researchers from Visteon UK in Coventry to run the TIGERS project, claim the 'free power' breakthrough will make engines more efficient; reduce emissions and create enough electricity to run all of a vehicle's power systems.
And the group claims the simplicity of the technology will allow it to be fitted on all car, van, bus and truck engines over the next few years.
The invention could also spell good news for road users as it is predicted that TIGERS – Turbo-generator Integrated Gas Energy Recovery System – could reduce fuel consumption by up to 10 per cent.
The system works by installing an extra waste pipe where the exhaust system joins the engine. A valve, linked to the engine's management control system, allows some of the high energy gases to be drawn off to drive a special generator, using a switched reluctance drive (SRD) device.
A switched reluctance motor has a rotor which has no magnets or windings and is effectively a piece of shaped iron.
The energy tied up in the high temperature exhaust gas can reach 130mph and can spin the generator at up to 80,000 rpm which creates an electrical power of up to 6kW – enough to drive a car's electrical systems.
Dr Richard Quinn, one of the engineers leading the TIGERS project, said the system could be developed to produce anything from 12 volts to 600 volts, which could drive a car's heating, lighting, air conditioning and in-car entertainment systems.
Dr Quinn, of Visteon's European Powertrain operations, said: "TIGERS is a really exciting development.
"Up to a third of the power that a conventional engine produces is wasted as exhaust gases. By harnessing some of that power we can make the engine more efficient." Looking longer term, the project's leaders feel the cam belt, drive belts and alternator could be scrapped and TIGERS electric drive used instead, helping to reduce friction losses.
In an electric car the team, which is working under the Society of Motor Manufactures and Traders Foresight Vehicle research initiative, claims the TIGERS system could feed the 'free' power directly to boost the main drive motors, or back to the battery to give the car an even greater range.
On lorries the team said the extra electricity could be used to power electrical systems to run refrigeration units for chilled food, turn the motors on cement mixers or power pumps on fuel tankers.
Technology transfer company SR Drives develops drive systems and has the world's largest switched reluctance technology patent portfolio. The company's Harrogate site includes extensive testing, laboratory and manufacturing facilities.
More than 400 British companies and universities have been participating in the industry-backed Foresight Vehicle initiative, which is led by the Society of Motor Manufacturers and Traders.
The initiative aims to improve the efficiency of transport systems by meeting modern expectations for mobility, and satisfy strict environmental and safety requirements.