Combustion-engine efficiency boosted by 10 per cent after decade-long research
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The efficiency of internal combustion engines can be boosted by 10 per cent thanks to a new system that selectively opens and closes valves.
The product of a decade of research, this patented system could significantly reduce fuel consumption in everything from ocean-going ships to compact cars.
“This method has the potential to bring the well-established benefits of a fully variable valve system out of the lab and into production engines because cost and complexity aren’t issues,” said Amir Khajepour, a professor of mechanical and mechatronics engineering at Waterloo.
Intake and exhaust valves in internal combustion engines are typically controlled by cam mechanisms that do not allow the timing of their opening and closing to be varied.
The technology developed by Waterloo researchers replaces cams with hydraulic cylinders and rotary hydraulic valves that enable fully variable timing as the speed and torque of an engine change.
This ability to specifically time the opening and closing of valves according to engine operation is a key to increasing fuel efficiency, reducing both costs and greenhouse gas emissions.
“If you think about an ideal solution, it is to make the motion of the valve completely controllable,” Khajepour said. “That gives you infinite options to work with.”
Although other systems to vary valve timing already exist, they are limited to use in experimental engines in laboratories due to their high cost and complexity.
The technology developed and tested at Waterloo is much simpler and far less expensive, paving the way for its use in engines for power generation, mining vehicles, the trucking industry and a host of other applications, including the consumer automotive market.
Khajepour said an affordable, reliable method to vary valve timing in internal combustion engines could substantially reduce our carbon footprint during the transition to cleaner electric powertrains over the next few decades.
“We should be able to easily improve efficiency by over 10 per cent, which is significant,” he said.
Last year, Mazda revealed that it had developed a new petrol engine that is up to 30 per cent more efficient than others used in the industry.
The technology allows standard petrol engines to achieve the same levels of efficiency as diesel engines without the toxic emissions.