New Holland | Company continues with selective catalytic reduction to meet Tier 4B emission requirements
BAKERSFIELD, Calif. — Tier 4B emission requirements are prompting most farm machinery manufacturers to add hardware and/or cubic inches to their engines so they can maintain power and efficiency.
No heavy duty diesels can yet meet the 2014 emissions standards without the addition of urea in the exhaust flow. However, New Holland’s current crop of high horsepower machines will do it without re-burning exhaust or particulate filtration.
David Kohuth of New Holland said the Fiat Powertrain Technologies engines have been engineered to meet a fine balance. They fall between generating low nitrous oxide production with low temperatures in the combustion chambers and low particulate matter creation with high temperatures in the combustion process.
“It is a challenge to get both. We deal with the emissions by managing the whole process,” Kohuth said.
Off-highway standards have arrived in Europe and North America later than for highway applications.
Fiat’s Iveco trucks had to start meeting lower emissions beginning in 1995. The company is now the world’s third largest diesel engine builder.
“To meet the Tier 4B numbers, we had to increase the amount (of diesel exhaust fluid or urea) that is used, but in the process we simplified our (systems),” Kohuth said.
Case New Holland found it could take what it had been learned in on-highway systems and apply much of it to its farm machinery.
The use of the selective catalytic reduction-only (SCR) solution, called Ecoblue Hi-eSCR, was increased to eight percent of its total daily fluid consumption from six.
A change in the catalyst’s materials to handle higher temperatures allowed for the bonding-off of the nitrogen oxide, which created emissions of nitrogen and water from the greenhouse gas.
Kohuth said the increase in diesel exhaust fluid (DEF) use is offset in other designs by the need to filter particulate matter and feed exhaust gasses back through the engines.
“Competitors have to add a second turbo charger. They need to cool the exhaust gasses they re-circulate through their engines. We don’t have any of that additional equipment or electronics to support it, just SCR,” he said at a dealers’ training program held on a farm near Bakersfield, California.
“Some companies have had to add more than just additional equipment. They needed to add cubic inches to the engines to make the equivalent power they had before. We didn’t need to do that either.”
One of the advantages of not re-circulating the exhaust gases comes from longer service intervals. The company recommends oil changes at about 600 hours compared to 350 to 500 for competitors that use exhaust gas recirculation.
“There is less to service, less to wear out and less to build in the first place,” he said.
“Our (fluid) efficiency is a wash with our competitors, but the overall picture gives us an advantage, we think. We think farmers will see that, too.”
Managing the New Holland solution did require the addition of extra sensors and the computer software to make use of them. One sensor tracks the quality of the urea in the DEF tank, another looks at the exhaust contents and another at the final emissions from the stack. A computer then analyzes the data and controls the flow of the DEF accordingly to keep the amount of nitrogen oxide within limits.
Engine temperature is critical to obtain the right burn quality, so a new exhaust damper chokes the engine during the warm-up phase to cause a rapid warming of the system before reaching operating temperature when it kicks out.
Outwardly, the changes to the New Holland machines appear only as larger exhaust stacks, housing the new catalyst systems.
To watch a Western Producer video interview about the T4B system at New Holland, visit producer.com/sections/video.