Hybrid reefer offers big savings

This was the head on the intro story I did on the Carrier Transicold Vector 1800MT back in 2006. The subhead told the story: A revolutionary truck refrigeration unit offers hybrid fuel economies and major maintenance savings.

And what was true then is even more so now, as a news release received recently spells out: Mile Hi Foods, a Denver-based refrigerated food service distributor that has 27 Vector units – second-generation Vector 6500s and multi-temperature 6600MTs – is generating huge savings using electric stand-by. By piggybacking on the unique diesel-electric Deltek hybrid architecture of the Vector units, this relatively small trucking operation is saving $85,000 per year and offering customers a smaller carbon footprint.

Uniquely, the hybrid diesel-electric Vector units have all-electric refrigeration architecture. Unlike mechanical refrigeration systems, the diesel engine is dedicated to one function: driving a high-performance generator, which powers the compressor, fans and operating system. Because they are basically electric, when stationary, Vector units can be plugged into an electric power source, eliminating the need to run the engine.

When plugged into electric standby, fuel is conserved, emissions are eliminated, noise is reduced and operating savings of 40 percent to 70 percent can be achieved, depending on the price of fuel and electricity at any given time.

To gain the fuel economy, cost savings and competitive advantage, Mile Hi Foods – already a convert to the Vector principle – added 17 460-volt electrical outlets to its loading docks and installed 20 freestanding receptacles in its yard. Loaded trailers can now be parked and run electrically while waiting to be dispatched.

“The driving factor was when fuel got up to $4 a gallon,” says Tony Taddonio, president of Mile Hi Foods. “It made us rethink a lot of what we were doing. As we considered how we could save energy, we saw the sustainability benefits, too. This was perfect. It fit everything we wanted to do.”

Mile Hi Foods calculates it is saving 1,800 gallons of fuel a month by using electric standby, which over the course of a year, reduces its fuel expenditure by more than $85,000, enough to pay for the infrastructure investment.

Now that’s good news. But it was just as good news five years ago when I first heard about the new hybrid Vector. In fact, I was sufficiently excited that I jumped on a plane to Athens, Ga., to interview the Carrier Transicold folks and marketing leader Ignacio Aguerrevere. Over the course of two days, I managed to dig deep into the revolutionary technology to better understand not so much why this hybrid was a good thing, buy how the hybridization had been accomplished.

Let me go back to my 2006 story . . .

The revolutionary Deltek (Diesel-Electric Technology) reefer system uses the same 2.2 liter Kubota diesel engine that powers Carrier’s Ultra and Ultima reefer units but that’s about all that’s common with existing equipment.

Key to the performance and reliability of the Vector is the electric power for the reefer components, generated by the diesel engine and a special generator, supplied by United Technologies partner company Hamilton Sundstrand, a leading aerospace supplier. This generator supplies power for the electrically driven compressor from the marine side of Carrier’s business, where refrigeration systems of great reliability run unattended on container ships during lengthy transoceanic voyages. Electric power is also used for the fans, the heat and defrost cycles of the reefer unit, and battery charging. And because the refrigeration side is electric, the Vector offers 460-volt plug-in standby as part of the package.

That shows the farsightedness of this innovation.

Simple reliability

In addition to saving fuel, most of the problems associated with reefer maintenance and leakage are addressed by the Deltek hybrid technology. Because the compressor is electrically powered, there is no mechanical drive from the diesel engine and therefore no potential refrigerant leakage through the powershaft seal. In fact, the whole six-cylinder, high-performance compressor and electric motor assembly is sealed with only electrical and refrigerant connections passed through the housing.

And since electric resistance power strips are used for the heat and defrost cycles, the refrigeration circuit is far simpler, with no need to incorporate a hot-gas heating cycle. As such, the Vector has no solenoid valves or check valves, or any of the associated pipework. And it has only about half as much refrigerant as a conventional transportation refrigeration unit.

Further simplifying the unit is the use of electric, instead of mechanically driven fans. Not only does this allow for more accurate tailoring of the cooling and discharge, electric power means no complicated and trouble-prone belts and belt adjustments. It also makes for a more compact unit than conventional reefers. Gone are belts, idler pulleys, vibrasorbers and clutches, along with the associated need for regular service. In fact, the only belt is the alternator drive belt on the Kubota engine.

With up to a 66 percent reduction in parts and use of the aerospace generator and ultra-reliable container-ship motor/compressor, Carrier is predicting a reduction in lifecycle costs of 30 percent with an extended service package included that allows for 3,000 hours – which could be as much as two year intervals.

MultiTemp application

In 2006, the Vector 1800MT was new to North America, but it had been running for several years in Europe where it was a proven technology. It was introduced in North America as a reefer unit for multi-temperature trailer applications, since these are among the more demanding and also because multi-temp applications are on the increase.

Since then, the second generation Vectors were introduced in 2010, as the 6500 for single-temperature reefers and the 6600MT for multi-compartment trailers up to 53 feet long.

Adding to the versatility of the Vector is the Advance microprocessor control that delivers precise refrigeration control, driver set-up ease and exclusive fuel optimization options. Advance control has two programmable software features: IntelliSet and ProductShield.

With IntelliSet, a fleet manager can set up as many as 30 commodity profiles, each with its own characteristics for temperature control, from the Carrier PC based ReeferManager software. These profiles can have names that reflect the produce, for instance, so once uploaded to the Advance controller – and it can be done fleetwide once the parameters are set – a driver simply scrolls through the list to find the commodity, such as strawberries, frozen fish, or ice cream, for example. The Advance microprocessor automatically adjusts for the best temperature control at the optimized fuel-efficiency mode.

ProductShield uses information from temperature sensors inside and outside the trailer to determine whether continuous-run or auto stop/start for any given commodity according to ambient conditions. In its latest 4.03 release, the Advance software offers additional fuel economy in high-air mode.

SIDEBAR

Running a conventional refrigeration unit from an AC electrical source involves an almost cost-prohibitive add-on. But even with this, electric standby capability is growing in importance to refrigerated haulers for several reasons. It:

• Conserves diesel fuel for the road.
• Reduces engine wear.
• Eliminates emissions from the refrigeration unit.
• Eliminates engine noise during loading and unloading, important for supermarkets and restaurants located in suburban neighborhoods.

With California Air Resources Board’s Airborne Toxic Control Measure (ATCM) may be the most important benefit of standby is:

• Complies with regulations, especially in California where use of electric standby at the loading dock is one of the approved methods for compliance with diesel emissions regulations. (Go to www.arb.ca.gov/diesel/tru.htm.)

But look at the potential savings of the hybrid/electrical combination. Here’s an admittedly self-serving Carrier Transicold analysis. But it’s impossible to ignore.

Estimated Standby Savings (High-speed mode, high-capacity demand)
Cost Of Operation - Diesel
	Hourly fuel consumption	1.15 gal
	Cost per gallon diesel fuel*	$3.89
	Cost per hour to operate on diesel	$4.48
Cost Of Operation - Electric Standby
	Amperage draw	31 amps
	Voltage	460 volts
	Power consumption	14.43 kilowatts
	Cost per kilowatt hour**	$0.1030
	Cost per hour to operate on electric standby	$1.47
Cost Savings - Electric versus Diesel
	Savings by operating on electric standby	67 percent
*Average price of No. 2 diesel retail sales by all sellers, U.S. DOE ** Average commercial price of electricity, U.S. DOE Table courtesy of Carrier Transicold