In a presentation to leading North American-based business journalists on May 4 in Miami, powertrain expert Dave Hahn has highlighted Volvo Construction Equipment’s (Volvo CE) four point strategy to answering the call for long term, significant and sustainable machine efficiency.
“Engine technology continues to make tremendous strides in finding improvements in fuel efficiency while at the same time reducing harmful emissions,” Hahn said. “But this alone will be insufficient to meeting our long term environmental and productivity goals — others influence total machine efficiency. So Volvo CE is addressing the issue of machine sustainability from a holistic viewpoint, one that includes engines, but also systems, emerging technologies and even operator behavior.”
Engine Development — A Tier IVi Success Story
Developed to meet the requirements of U.S. (EPA) Tier IV interim legislation, the new generation V-ACT (Volvo-Advanced Combustion Technology) engines feature ultra-high pressure variable fuel injection systems, cooled exhaust gas recirculation (EGR), precise control of the turbochargers, powerful new EMS engine management systems and an integrated exhaust after-treatment system that features a particulate filter and thermal regenerator.
The new units feature exhaust gas recirculation (EGR), which lowers the amount of oxygen in the combustion chamber, reducing combustion peak temperature and in doing so lowering the formation of nitrogen oxides (NOx), a key requirement of the new regulations. As Tier IV interim engines require low sulphur fuel a new cooled EGR system has been designed that allows more exhaust recirculation than the previous uncooled generation, thereby lowering NOx further.
The reduction of particulate matter (PM) from diesel engines is another requirement of the latest regulations. The new Volvo system uses an advanced exhaust after treatment system that reduces particulate matter by 90 percent compared to the previous machine series. The filter traps the particulates and temporarily holds them until there is a sufficient build up to merit “regeneration”. This is effectively incinerating the particulates at temperatures above 700C, turning them to ash using a thermal regenerator.
Systems — Optishift Moves the Game On
The driveline system also plays a significant factor in overall machine efficiency — as evidenced by Volvo CE’s Optishift technology, which optimizes fuel savings by up to 15 percent. Designed for the company’s larger wheel loaders, OptiShift is a refinement of Volvo’s APS driveline concept. It combines a new torque converter with Lock Up and free wheel stator with Volvo’s Reverse by Braking (RBB) function — providing reduced fuel consumption, increased operator comfort and durability.
In short cycle loading it is common to use the gear shifter to change between reverse and forward without applying the brakes — deceleration is handled by the torque converter. This method is less efficient than using the brakes, results in energy loss and places undue strain on the torque converter. Volvo’s RBB system is a braking feature that automatically assists machine deceleration by using the standard service brakes instead of the torque converter.
The operator handles the machine in the same way as normal, but when switching from forward to reverse using the shifter the RBB system recognizes the speed, direction and throttle position and applies the service brake to slow the machine. This provides a smoother deceleration and direction change, and since the converter is no longer used for braking, wear and fuel consumption are both reduced.
The Operator — Making the (Right Kind of) Difference
It has long been recognized that the operator has a large effect on fuel consumption and productivity in today’s machines. Volvo Eco Operator program is a good example of training that gives operators the practical and theoretical knowledge they need to become safer, more efficient and environmentally conscious while operating equipment. The program teaches operators correct machine operation and maneuvering as well as how to plan their work in the smartest, most efficient way. By following these techniques, operators can help save money on fuel, increase overall production and reduce maintenance expenses.
Eco Operator consists of classroom theoretical training and practical, hands-on experience. The content can be customized with additional modules such as environmental training, simulator based training and on-site follow-up. For the operation portion, a trainer sits with the operator in his own machine on an actual jobsite. The trainer gives guidance on how to change behavior in order to operate more fuel efficiently. This not only helps operators learn on a machine they’re already familiar with, but the training course does not disturb the normal operations of a jobsite — so workers stay productive.
Major contractor Skanska was one of the companies to enroll its operators in a similar scheme. In one study where 37 operators were given training, it was found that fuel consumption reduced by 5 percent — representing savings of more than $320,000 and a reduction in emissions of 551 tons of carbon dioxide. Some operators reduced their consumption by 25 percent.
For more information, call 717/532-9181 or visit www.volvo.com.