Engine efficiency is streets ahead
by Geraldine Hinter
UniSA researchers have developed a process that can generate up to 20 per cent greater fuel efficiency from engines by capturing the heat energy lost to the exhaust and engine cooling systems in motor vehicles.
In current motor vehicle engines, less than 30 per cent is delivered to the wheel, because 70 per cent or more power is lost - about 30 per cent of the total potential power lost goes to exhaust heat, 30 per cent to the radiator that cools the engine and 10 per cent accounts for other losses such as friction heat.
Using a generator as a test engine for the research, Program Director in UniSA’s School of Advanced Manufacturing and Mechanical Engineering, Dr Saiful Bari has been successful in improving fuel efficiency from less than 30 per cent to about 50 per cent using the same amount of fuel.
"We collect the heat normally lost to both the exhaust and the radiator and use a heat exchanger to cool that heat energy to less than 90C before reheating to about 300C. Through this exchange, the heat is turned into a vapour that we run through a turbine to generate extra power," Dr Bari said.
"Being able to improve efficiency by 20 per cent is a huge cost saving."
This research can be applied to any fuel engine. Initially Dr Bari targeted diesel engines because they produce a greater level of heat than petrol engines and diesel engines are bigger.
"Space is a problem in cars because there is limited or no room in the engine compartment for the heat exchanger and turbine, therefore we are looking at applying this technology in stationary power generators," he said.
"Once we have settled on the optimum design of the heat exchanger, we will also apply this technology in trucks and buses. These big engines, which use more energy, have more space available for a heat exchanger and the turbine can sit on the side of the engine."
The $100,000 project is being funded by Leartek Pty Ltd with the generator supplied by Kidman Holding Pty Ltd. Dr Bari expects to have a good result by the middle of 2009.