Internal combustion engine can look forward to 30 more years of healthy life, says Ricardo director

Citation

(1999), "Internal combustion engine can look forward to 30 more years of healthy life, says Ricardo director", Industrial Lubrication and Tribology, Vol. 51 No. 5. https://doi.org/10.1108/ilt.1999.01851eab.007

Internal combustion engine can look forward to 30 more years of healthy life, says Ricardo director

Internal combustion engine can look forward to 30 more years of healthy life, says Ricardo director

Keywords: Combustion, Ricardo

The conventional internal combustion engine has another 30 years of life ahead of it according to Mike Monaghan, technical director at Ricardo - one of the world's foremost independent powertrain and vehicle engineering technology providers.

Mr Monaghan - who is responsible at Ricardo for research activities, patents and a number of projects involving novel combustion concepts and engine configurations -- drew this conclusion while delivering the annual prestige lecture to the Automobile Division of the Institution of Mechanical Engineers.

"All the potential non-internal combustion competitors are expensive or lacking in some major performance aspect", concludes Mr Monaghan. "Even with changes in urban transportation patterns there will still be a need for conventional light duty vehicles.

"The internal combustion engine has created a particular combination of cost, performance, power density, range and usage patterns against which any competitor must bejudged", he added. "Without major changes in transportation behaviour this combination is unlikely to change." Mr Monaghan cited improvements of the order of 20:1, for example, for even the most advanced battery-electric vehicles to match the diesel or gasoline system. Even the sodium-sulphur battery would weigh over 1.5 tons and occupy more than 1,500 litres to match the fuel weight and volume equivalent to 50 litres of gasoline.

"It is true that the battery electric vehicle is virtually non-polluting on the roads where it is used", said Mr Monaghan, who is currently Co-chairman of the EuroCASE working group on Urban Air Quality. "In the UK, however, where most of the electricity is generated from fossil fuels at modest efficiency and then distributed with various losses, the impact on air quality or global warming of these vehicles would at best be modest." Meanwhile, features common to hybrid vehicles - two sources of power, two storage systems and their complex control system - means that any hybrid is more costly and weighs more than a single power source vehicle. Consequently, while hybrid vehicles are now available, they could not achieve significant sales volume if they were priced at realistic levels.

The least developed and most promising competitor to the internal combustion engine is the hydrogen fuel cell, whose operation is not only free of pollution (theoretically) but also free of the Carnot cycle restrictions, so high efficiency should be possible. However, unless an infrastructure is developed to provide liquid hydrogen as the fuel, the fuel cell vehicle will need to rely on a liquid hydrocarbon fuel. That forces the need for a reforming plant, which degrades the efficiency of the power system because all the carbon in the fuel is "thrown away" as 002 (some is also thrown away as CO). The reforming plant is heavy, costly and limited in its transient response.

"Although a practical fuel cell vehicle using hydrogen could be made available by 2004, as predicted by a number of manufacturers, it is most unlikely that it would be remotely close to the cost of an internal combustion engine", said Mr Monaghan. "And it is equally unlikely that the infrastructure to provide the hydrogen would be in place at that time".

Petrol versus diesel systems

"My conclusion is that over the next 30 years the light duty diesel will continue to co-exist with gasoline and gas engines", said Mr Monaghan. "And while the direct injection gasoline engine can show real gains, even at its full potential it will not match the efficiency of the diesel".

In Europe, there is already a very strong "diesel culture". In 1998, of the 15 million cars sold, 3.6 million or almost 25 percent were diesels, and a similar culture is emerging in Asia.

While it is clear that emissions legislation is becoming tighter everywhere in the world, the adoption of new technologies has enabled diesel to keep ahead of the legislation. The latest common rail fuel injection equipment and advanced combustion systems, for example, are showing that even Euro 4 in 2005 can be achieved without after-treatment.

The ever-tightening emissions legislation is beginning to have an impact on air quality, and forecasts for most developed areas of the world show reductions in all the major pollutants. Modelling carried out for the UK government predicts massive reductions in NOx as the Euro 3 and then Euro 4 legislation begins to show in the output from newer vehicles. Already, total NOx emissions in the LTK have more than halved from their peak level in 1990 and are now probably below the level in 1970. Similar reductions in particulates from transport have also been achieved.

Despite the very significant reduction in emissions achieved by modern diesels, Mr Monaghan conceded that emissions legislation must be regarded as a real threat to its survival. LEV2 legislation recently approved in California - which demands virtually zero emissions - is such that there seems no practical and economic way of modifying the combustion or fitting after-treatment (of any kind).

Traditionally, the US Government has followed California, but it is also obliged to honour the Kyoto Pledge, in which it undertook to reduce 002 emissions by 7 percent by the year 2010. Recent studies by the US Department of Energy have shown that a 25-30 percent penetration of the light duty market by diesels (similar level to that in Europe) would actually give three of those seven percentage points.

The most important feature of the light duty diesel is its efficiency compared with any other current prime mover. The efficiency in specific fuel consumption is matched by its low 002 output, especially when the full "well to wheel" production process is taken into account.

"Although the diesel engine has improved enormously, so has the gasoline engine, and it will continue to improve in the future", said Mr Monaghan. "Several technologies under development apply to direct-injection gasoline engines, and it is in this area of technology that the main improvements in gasoline engine efficiency may be found - but it is probable that the direct injection diesel will remain well ahead".

For more information contact Mike Monaghan. Tel: +44 (0) 1 273 794103.