The most significant challenge in the evolution of off-highway diesel engines will be compliance with future exhaust gas emissions limits while also achieving low fuel consumption and low CO2 emissions.
Imagine being a student getting ready to take an important engineering exam. Your professor hands out the exam and you find that there is only one problem. To pass the class, you must design a diesel engine that can fit in the specified envelope, generate a massive amount of power, operate for upwards of 20,000 h before overhaul, burn less fuel than any previous model, be easily serviceable, and emit only harmless substances into the environment. While this is not a real test problem on an engineering exam, it is a real-life challenge that diesel manufacturers will have to grapple with in the not-so-distant future.
Like a good student who is mindful of environmental concerns, MTU has been preparing for this exam for several years. Our engineers have been hard at work optimizing our engines to improve combustion efficiency through the use of such technologies as common-rail fuel injection, changes in valve timing, and combustion chamber geometry. These so-called “in-engine” design improvements have accomplished remarkable reductions in all of the emissions products in diesel exhaust NOx, hydrocarbons, and particulate matter. However, to meet the requirements of U.S. EPA Tier 4 and beyond, additional technologies will be necessary.
Being on the leading edge of technology is nothing new for MTU. Over the course of our 100-year history, MTU has been known for its technological leadership—first in engine development, then in systems design, and now in exhaust aftertreatment. Our development philosophy has always been to keep key skills in-house to produce customized solutions for our customers.
We began with the key technologies of fuel injection, turbocharging, and electronics. With the emissions-reduction landscape continuing to define the evolution of our industry, we are extending our armory of in-house key technologies to include exhaust aftertreatment systems.
To that end, we recently set up a joint venture with Hug Engineering, a leading Swiss company in the area of exhaust aftertreatment, which has supplied more than 1000 selective-catalytic reduction (SCR) systems for retrofitting of diesel engines in locomotives, ships, and industrial applications.
Together we will be designing smaller and lighter systems than have previously been available. In addition, our solutions will have lower life-cycle costs than conventional SCR systems. The global acceptance of SCR is growing rapidly, as evidenced by on-highway engine manufacturers who have turned to SCR to meet the emissions requirements beginning in 2010.
While 2020 is still down the road a bit, the foundation for solutions is being laid now. The current economy may be weak, but progress cannot wait. Investments in key research and development programs will bring the off-highway diesel engine industry through the requirements of 2011, 2014, 2017, and whatever new requirements the future holds. At MTU, we’re sharpening our pencils, getting ready for that important exam.
Matthias Vogel, CEO, MTU, wrote this article for SAE Off-Highway Engineering.