|
Diesel engine revving up for the future |
|
 There’s potential for unparalleled efficiency and lower emissions in diesel engine technology, says Volvo.
Pressure for the development of environmentally optimized technology is increasing, but the answer need not lie solely with electric and hybrid solutions.
Tomorrow’s most energy-efficient engines are already more than a
hundred years old. All the indicators are that the diesel engine still
has a lot to give.
Today the diesel engine is one of the most exciting and promising
technologies in the hunt for new engine solutions for an increasingly
eco-aware and resource-efficient world. The reason for the diesel
engine’s success lies in Rudolf Diesel’s original idea: to create an
engine with the maximum “thermodynamic efficiency rating” – something
that is achieved when as much as possible of the fuel’s energy is used
to propel the vehicle instead of literally going up in smoke. What is
special about the diesel engine is that it compresses both air and fuel
under immensely high pressure. When the fuel in the cylinder ignites
owing to the heat generated by the high degree of compression, this
generates the power that sets the piston in motion.
The development of the diesel engine can be divided into three stages.
The first step was the rapid development of the fuel injection system.
The second was the development of new air compressors. The most recent
major step came with the development of the electronic common rail
injection system at the start of the 1990s.
The diesel engine is about 20 percent more fuel efficient than a
gasoline engine. For one thing, you can get ten percent more energy out
of a litre of diesel than from a litre of petrol, and for another, the
diesel engine operates about ten percent more efficiently than the
petrol engine does.
The diesel engine’s high energy efficiency puts it in the lead even
when it comes to emissions. However, it was long regarded as “dirty”
since it produced large quantities of visible smoke consisting of
unburned carbon. Nonetheless, with the development of modern particle
filters these emissions have been cut to a minimum. And with the latest
SCR (Selective Catalytic Reduction) technology, emissions of nitrogen
oxides too have been considerably reduced.
Clear-cut examples of how the diesel engine has been improved over the
years can be found for instance in the Volvo Trucks’ engines, which in
the space of just 20 years have become 100 times cleaner in terms of
emissions of climate-impacting air pollutants.
Through optimized combustion and improved exhaust filtration, engines
in the latest Volvo Trucks driveline range have also been made both
more fuel-efficient and cleaner than ever. For a truck with the
best-selling 13-litre engine and automatic Volvo I-Shift transmission,
for instance, fuel consumption and carbon dioxide emissions are cut by
up to three percent in one single move.
But if all this is already history, what can we say about the diesel engine’s future?
There is immense potential in the new diesel technologies that are
currently being developed. Biofuels can help further cut emissions. And
hybrid diesels with single-point technology, where the diesel engine is
optimized solely for long-distance operation, for instance, may promote
both higher efficiency and lower production costs in the future.
From an article by Tobias Hammar for Minnett Media
|
