Diesel Technology Enters the Next Frontier

As GSE manufacturers gear up to offer Tier 4 interim engines, what are the implications for operations on the ramp?


JBT AeroTech has been planning for a Tier 4 interim engine since May 2008, working with an engine manufacturer for a 260-horsepower engine for its Air First version of Tempest deicer. The engine uses a cooled EGR/DPF technology.

According to Ed Sachs, deicer engineering manager at JBT AeroTech, the engine is currently being outfitted with specific modifications, with delivery to the company’s facility occurring in July or August. The engine will be installed with validation and testing in the September timeframe. The company plans to demo the equipment around October.

Another GSE manufacturer, TLD, has been working with the Tier 4 interim technology for more than a year. The company has been working on Tier 4 interim implementation in both the U.S. and Europe, according to Peter Owitz, chief operating officer at TLD ACE.

Speaking specifically about the company’s GPUs, air conditioners and jet starters, Peter Owitz says the company has worked on designing equipment to fit both SCR and EGR/DPF technology for more than a year. The company is starting to test units with Tier 4 interim engines, he says.

Hobart Ground Power has also been working on the Tier 4 interim design for its products within the applicable horsepower range for 2011. Beginning the process in 2007, the company now has one engine with EGR/DPF aftertreatment currently in testing, according to Nat Phillips, engineering manager at Hobart.

Challenges for OEMs

The manufacturers have had to design the equipment to accommodate the larger engine and aftertreatment packages in the cabins. “For the engine manufacturers that are selecting DPF technology, total heat rejection will increase by between 30 and 50 percent,” Owitz says. “This will cause radiators to increase in size and, in some cases, unit volume to grow.”

He continues, “And for the engine suppliers that are choosing to use SCR technology, the unit will require additional space for another tank and the infrastructure to move the DEF around the unit.”

JBT AeroTech pointed to the availability of ultra-low-sulfur diesel fuel as another challenge for OEMs. “If you’re selling to a global community such as we do, we have to be very careful who our end-user is and be certain of the type of fuels that they’re using,” Sachs says. “The tier 4 engines utilize an ultra-low-sulfur diesel fuel. There are a lot of countries around the world that do not have that fuel as an offering. So it makes it a challenge for us as a manufacturer to make sure that we really understand who our customer is and where that unit is going to be placed.”

Impact on the Ramp

The manufacturers spoken with say they don’t expect much difference in ramp operations with the engines besides occasional maintenance practices.

“If the operator is using a piece of equipment that has an engine with an SCR in it, the only difference is that he will have to supply DEF into that unit,” Owitz of TLD says. “If it is a piece of equipment with a DPF, the operator will have no interaction with the engine aftertreatment due to the automatic regeneration cycle. If it gets interrupted for some reason or it is not allowed to run, there might be some operator action required.”

On the issue of low-duty cycle regeneration for cooled EGR/DPF on the ramp and whether or not the operation could facilitate enough heat for automatic (passive) regeneration, JBT AeroTech says the design of its model would promote it. “In our current products, it is the sole engine for the entire deicer so it’s running over a more varied engine RPM and we’re actually holding it at the higher loads much more,” Sachs says.

TLD also says the design of its products would adequately facilitate passive regeneration on the ramp.

And in its testing so far, Hobart has recorded sufficient passive regeneration. “The heat rejection of the engines has significantly increased and it appears that the ‘Passive Regeneration Mode’ is the primary operating mode for the DPF system,” Phillips says.

Heading into testing, JBT AeroTech and TLD say they don’t expect an improvement in fuel economy for either technology.

Hobart, on the other hand, has witnessed promising results in testing for fuel economy with the EGR/DPF technology, according to Phillips.

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