Is the age of the internal combustion engine coming to an end?
The debate surrounding the use of SCR and EGR technology continues to captivate the industry. Research into agricultural technology is becoming increasingly devoted to alternative and low-emissions drive systems such as hybrid solutions, biodiesel variants and e-mobility. Fuel cell research is also attracting particular attention at present. Many experts also see a viable up-and-coming alternative in hydrogen technologies. In other words, the age of technological change is upon us.
New drive systems.
A split from the internal combustion engine appears a done deal, both on the road and in the agricultural sector. Hybrid solutions, diesel-electric drive systems and electric engines are set to play a much more central role in agriculture in the years to come. Initial models and prototypes have already shown us the way forward.
A time for unrestrained elation, particularly with regard to electric mobility, is not yet upon us, however. We still have some way to go before economically feasible e-solutions are a reality. Academic and industry research in these fields, however, is in full swing. “In future, tractors will be the most prevalent users of electric energy sourced from a power outlet”, states Thomas Herlitzius, Professor of Agricultural System Technology at the Technical University of Dresden. Electric drive systems are held to be a viable alternative to hydraulics; in the opinion of Prof. Herlitzius, “They guarantee improved controllability and efficient installation space utilisation, and boast higher standards of operational efficiency”. Furthermore, in electric drive systems, oil emissions in the coupling and decoupling procedures of hydraulic assemblies are avoided, and the risks associated with the handling of hydraulic fluids diminished.
Large-scale energy storage in hybrid solutions.
In addition to purely electric engines, a great deal of intensive research is also currently being carried out on hybridisation of the drive train of mobile machines. Hybrid drive trains can be powered electrically or hydraulically. The Cologne University of Applied Sciences is currently investigating how hybrid solutions are being implemented in practice. The University began the “Lib-OFF-Road” project in June 2010 together with partners from industry and the scientific community. The aim of the project is to develop energy-efficient and environment-protecting drive system designs for off-road commercial vehicles, e.g. construction, agricultural and forestry machines. Alongside the drive system for the machine itself, the investigators also hope to place the drive mechanisms for the operational implements in particular under the microscope, since these systems consume a great deal of additional energy. These also represent the crux in hybrid drive systems, requiring a major energy storage device. The technology to realise this must now be developed.
Diesel-electric drive systems for off-road machines.
Diesel-electric drive systems are also currently becoming established as a viable and appealing alternative. In these systems, the engine acts as its own generator, powered by a diesel engine. Scientists at the Technical University of Dresden hope to use electric drive systems to reduce the noise of and increase the efficiency of agricultural machinery. In their research, the scientists developed a diesel-electric drive system in which a diesel engine powers an onboard electric system, which, in turn, powers the tractor’s four wheels. According to the researchers’ findings, this hybrid tractor achieves extremely favourable rates of efficiency, with further advantages to boot: “When all four wheels are driven individually, greater tolerance is afforded with regard to different tyre radii as well as reduced tyre wear. Active traction control for each wheel helps protect the soil and increase traction”, states Agricultural System Technology Professor Thomas Herlitzius.