VANCOUVER, B.C. - With the major truck engine manufacturers scrambling to meet 10/02 emission standards, a Canadian company is looking well beyond October for a long-term solution for the trucking ind...
VANCOUVER, B.C. – With the major truck engine manufacturers scrambling to meet 10/02 emission standards, a Canadian company is looking well beyond October for a long-term solution for the trucking industry.
Westport Innovations has developed a natural gas engine – slated to hit the market in 2004 – featuring emissions reductions far greater than the options being considered for this fall.
The company’s ground-breaking natural gas technology has been applied to the Cummins ISX engine and before long, fleet owners will have the option of equipping their new rigs with the natural gas alternative.
Many fleets have shied away from natural gas in the past, because of compromised fuel economy and torque.
Westport says, however, it has addressed both of these issues with its proprietary high-pressure direct injection (HPDI) system.
“The natural gas engine will be cleaner and, for the first time, will match the torque and fuel efficiency of the diesel, which has typically been the weakness of natural gas engines in the past,” says Bayless.
In fact, while the company has been able to match the fuel efficiency of diesel engines, Westport is shooting for a two per cent improvement over today’s diesel engines when all is said and done.
What enables Westport to overcome the major challenges facing natural gas engine-makers is its HPDI fuel injection system. Traditionally, natural gas engines have combined a mixture of air and natural gas during compression.
The result has been a volatile mixture making it impossible to match the hot compression ratio of a regular diesel engine.
“In order to avoid pre-ignition, the compression ratio is lowered and … (it) doesn’t give the same kind of torque,” explains Bayless.
So Westport searched for a way to avoid an air-fuel mixture that would compromise compression ratios.
The solution the company arrived at – millions of dollars later – was HPDI.
“The problem with natural gas is that it’s harder to ignite, so it won’t ignite consistently just from the heat of that hot compressed air,” explains Bayless.
“We had to add, in addition to the natural gas injector, a way to assist the natural gas to ignite.”
Westport’s team of engineers did so by developing a fuel injector that features two separate channels.
The first delivers a miniscule shot of diesel fuel into the cylinder to start the process of combustion.
The second channel delivers a larger amount of natural gas just a few milliseconds later.
“The result is that we get the same amount of energy into the cylinder at the same point in time as if it were a diesel, and we get the same torque and fuel efficiency because nothing else changes in the engine except for the injection process,” says Bayless.
In fact, under the hood of Westport’s test truck, it would take a well-trained eye to discern any differences between the natural gas ISX and a regular Cummins diesel.
The main visible difference on the truck itself is the fuel tank, which stores 150 gallons of liquid natural gas – enough for about 600km of driving.
There is also a smaller diesel tank on the side of the truck, but since so little diesel is used – the engine would lose its status as an alternative fuel engine if more than five per cent of the fuel used is diesel – the small tank rarely needs to be topped off.
In addition to the 16 test trucks in commercial use south of the border, Westport’s own test truck is given a full workout day in and day out.
The company certainly doesn’t baby this Kenworth, which pulls an 80,000-lb load throughout B.C. 24-hours a day, five days a week. So far it has racked up nearly 300,000km trouble-free since May of 2000.
When riding along with Westport engineer Doug Chambers and one of the company’s experienced truck drivers, the only noticeable difference of the natural gas engine is the sound – or lack of it.
The engine is much quieter than a diesel – a fact that has won many fans among the test fleet’s drivers in California.
“The drivers really like it because it’s so quiet and they don’t come home smelling like diesel every day,” says Chambers.
Another benefit of the natural gas engine is that drain intervals are extended by about 300 per cent.
Coupled with the lower cost of natural gas compared to diesel, and the fact emissions are no longer an issue, it’s reasonable to think a lot of fleet owners will be taking a hard look at natural gas when Westport’s engines reach commercialization in 2004.
However there are still some obstacles to overcome before the engine is widely accepted within the industry. The biggest problem is the accessibility of natural gas.
Because it’s not readily available at truck stops, any company wanting to add natural gas vehicles to its fleet would have to consider the $250,000 investment for a new filling station.
That’s not feasible for most linehaul operations where a fleet’s trucks are scattered across the continent, but for a local fleet that operates within a small radius of its headquarters, Chambers says the investment could pay off quickly thanks to the low-cost of natural gas.
“As the delivery system for natural gas matures it should become even less costly,” adds Bayless.
Another consideration that may deter fleets considering natural gas engines is the increased cost of the vehicles themselves.
The injection systems are not being offered as a retrofit or conversion kit, and Bayless admits the cost of a natural gas engine will be higher than diesel.
“Natural gas engines will be more expensive, but hopefully the lower fuel prices will offset that cost,” says Bayless noting it’s not the engine itself that will cost more, but the more complex fuel system.
Eventually, however, Westport is banking on more pressure from the government to burn cleaner fuels and a wider acceptance of new technology to help push its product into the limelight.
If natural gas engines catch on and filling stations begin offering the latest alternative to diesel, then there’s no telling how far this will go.
“You have a combination of the ability to lower emissions and lower fuel costs and those two things should make a good case for buying natural gas engines,” says Bayless.