As the heavy-duty diesel (HDD) truck world looks to likely future alternative power sources – battery or fuel cell – R&D into improving internal-combustion engine (ICE) efficiency continues. Digital valvetrain specialist Camcon Automotive is now claiming that potentially significant diesel fuel consumption reduction could be achieved using a combination of its iVT (intelligent Valve Technology) solution, which replaces the camshaft by using electric actuators, together with the use of advanced software and artificial intelligence.
Following what it terms a period of successful development of iVT in gasoline engines for passenger cars, including creation of a dynamic prototype, Camcon Automotive is increasingly focusing on the HDD market. Neil Butler, the company’s technical consultant, regards the project as “essentially launching the concept of the digital engine for HDD.” The company’s aim is to establish a collaborative program with an OEM or major supplier to develop a production-viable iVT system.
Camcon is claiming a fuel consumption reduction of up to 5%, with complementary reduction in emissions to help meet legislated limits and reduce the pressure on operators to move toward pure electric powertrain solutions. Depending on country, fuel costs over the lifetime of an average HDD truck could be some 1 million euros, making a 5% cut very significant, Butler said.
Camcon’s figures for annual running costs are based on a HDD truck operating in the U.K., averaging 9 mpg (imperial unit), burning diesel fuel at a cost of £1.15/liter and covering 85,000 miles (137,000 km) per annum, or about 230 miles (370 km) per day.
‘Infinite’ control of valves
By replacing the camshaft with electric actuators, iVT can ensure an “infinite variety” of valve events via changing timing lift and shape, Butler explained. This capability would contribute to reducing weight and packaging requirements of current aftertreatment equipment, he added, which can be extremely costly and may come near to equaling or even exceeding the price of some diesel truck engines. AdBlue consumption also would be reduced.
Butler said that although most aspects of the combustion process of HDDs utilize digital control, there is a gap to be filled: “Breathing has been stuck under the control of increasingly complex but essentially mechanical variable valvetrains (VVTs); iVT gives infinite control over the valves, bringing enormous benefits for HDD users, from cold-start emissions performance to exhaust gas recirculation (EGR), plus on-demand cylinder activation and management of harmful pollutants, including NOx.”
A further asset of iVT concerns catalyst performance. “Catalysts can be maintained at their optimum operating temperature over a greater proportion of the drive cycle,” Butler explained. To maximize efficiency, Camcon envisions incorporation of a suite of software that facilitates iVT being calibrated via machine learning to combine hardware and software into a single package.
At the U.K.’s University of Cambridge, David Cebon, director of the Center for Sustainable Road Freight and professor of mechanical engineering, stated: “Changing the powertrain of cars and trucks is inevitable. What technologies will win in the new era are as yet unknown. While the future emerges, it has to be acknowledged that conventional engines will be with us for at least the next decade, and probably a lot longer as part of hybrid powertrains.
“So, the industry’s responsibility is to make them as low impact to the environment as possible,” Cebon continued. “Technology such as digital control of valve timing – replacing camshafts with electric motors to increase engine efficiency – can make a significant and almost immediate reduction in fuel consumption and emissions, particularly when applied to HDD trucks. What’s more, innovation such as this requires no changes to existing infrastructure, saves operators money and lessens environmental impact.”Continue reading »