TECHNOLOGY OPDATE
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We've been through the introduction of Euro-1 and Euro-2 emissions regulations without too much pain. But Euro-3 is just around the corner: is it worthwhile, is it technically feasible—and how much will it cost hauliers ?
We need look no further than Athens, Pads or even London to realise just how vulnerable cities are to air pollution. Smog causes running eyes, sore throats and, increasingly, asthma attacks.
It's not a new problem, as anyone who lived through the London smogs of the 1950s will tell you, but the cause of the problem has changed, from the sulphurous products of burning coal to unburned hydrocarbons (HC), oxides of nitrogen (\10x), carbon monoxide (CO) and particulates (PM), caused by burning petrol and diesel fuels.
. I" I le UN Council for Europe introduced the first diesel emissions legislation—Regulation ECE R49—in 1982. and this formed the basis of the first EC legislation, 88/77/EEC.
The UK adopted this legislation, which can be thought of as Euro-0, for all newly registered vehicles six years ago on 1 October 1991. Euro-1, which introduced the control of particulates, came in on 1 January 1993. followed by Euro-2 on 1 October 1996.
As the table shows, the permitted emission limits have been reduced with each wave of legislation and by the time Euro.-3 is introduced on 1 October 2001, 10 years after
Euro-0, the overall reduction will be considerable. NOx will have been reduced by 66% ,CO by 800. and HC by 75%. PM was not controlled at Euro-0 but leading consulting engineer Ricardo estimates that the most dangerous PM10 particulates will also have been reduced by more than 75%.
As yet, Euro-3 is a European Commission proposal and it will have to receive the approval of the European Parliament before becoming a Directive, probably in mid-1998.1t is likely to apply to new types of truck from 1 October 2000 and to all trucks from 1 October 2001.
Denoc catalysts To take account of ever-improving technology, Euro-3 has been expanded to cover not only conventional diesels with Electronic Diesel Control (EDC) and Exhaust Gas Recirculation (ECK but also so-called advanced diesels using denox catalysts and particulate traps, and also spark-ignition engines running on alternative fuels such as natural gas and LPG.
The emission tests themselves have also changed. The basic 13-mode test is retained— it is now called the European Steady State Cycle (ESC)—and made more difficult by the introduction of a new random NOx test. Also, the old free acceleration smoke test has been replaced by a more rigorous transient smoke test made with the engine under load. This test, called European Load Response (ELR), together with the ESC test, will be used to test conventional and advanced diesels alike.
Jo formulating the new test procedures, a strong case was put for adopting the American transient type of test, and although this move was defeated for conventional diesels it has been adopted for advanced diesels anti spark-ignition engines running on alternative fuels. This new cycle is called the European Transient Cycle (ETC).
Both the ESC and ETC tests produce different results to the old 13-mode test, so the actual results are subjected to an agreed conversion factor to maintain the direct comparison with Euro-1 and -2. Manufacturers are quietly confident. The likely Euro-3 limits have been circulated within the industry for some time and with another three years to go before Euro-3 affects even new homologations, the their plans are well advanced.
Mercedes-Benz, which recently launched its new 500-Series engines in the Actros, says moving from Euro-2 to Euro-3 will be easier than getting from Euro-1 to Euro-2, And Renault VI's manager of corporate regulations, Etienne Godano, says: "All the necessary technology required to meet Euro-3 already exists." Fuel-injection manufacturer Bosch agrees, saying: "Euro:3 will demand near 100% use of electronic control and will be met by a variety of new diesel technologies, including electronically controlled conventional pumps, unit injectors and common rail systems."
Particulate traps
It is already dear that although devices such as variable geometry turbochargers and particulate traps are waiting in the wings, manufacturers are loathe to use them. RVI's Godano says particulate taps and the valves essential to the operation of an EGR system are not yet commercially viable.
Other devices, such as denox catalysts, are also unlikely to be used while the sulphur level in diesel remains at 500ppm. Godano explains that catalysts are "poisoned" by this level of sulphur, and that it would need a reduction to 3Oppm for them to work efficiently By the end of 1997. six years after the introduction of Euro-1, some 260,000 Euro-1 and Euro-2 vehicles will have been registered, compared with the official LGV pare of 413,00 units at the end of 1996.
Even allowing for a slight increase in the pare by the end of this year, more than 60% of all UK LGVs will have been subject to some form of legislation. In fact the parc has fallen steadily from 505,000 in 1989—and it is likely to fall further, to 400,000 vehicles, by 2000, by which time the number of Euro-1 and Euro-2 vehicles would have reached 350,000, or 875% of the total.
Emissions legislation is designed to improve air quality in cities hut if the present trend continues the UK will he paying a tremendous price in extra transport costs. It has to be asked if the ever diminishing reduction in NOx is really worth it. It remains to be seen what the fuel and oil penalty for Euro-3 will be (see box), but Euro politicians considering Euro-4 would be well advised to think hard and long before blindly giving the screw another turn.
7 by Gibb Grace
Next tnantk's Technology Update ?pill look at what
Exhaust Gas Recirculatm do for &My,
VVhile most Euro-2 engines maintained or even improved on Euro-1 fuel consumption, the chances are that Euro-3 engines will not. Bosch is unequivocal and says Euro-3 will lead to poorer fuel consumption. Gorran Hammarberg, responsible for Scania's engine development, agrees: "There is an obvious risk of increased fuel consumption." Ricardo's Chris Such is even more convinced. He says that the company's experimental work on Euro-3 engines shows a fuel consumption deterioration of between 5-8% against Euro-2 engines. This is a significant amount which could cost operators as much as £2,500 for a 38tanner covering 100,000 miles a year. Such says that using Exhaust Gas Recirculation (EGR) could cut the deficit to about 2.5-3.0 % and with further development work it could be reduced further, possibly to less than 2%.
However, EGR is far from proven at this stage, and Ricarclo's Such agrees with RVI's Etienne Godano that the valves essential to EGR operation are not yet reliable enough to withstand everyday operation.
Without EGR, the injection timing will have to be retarded and this will inevitably result in additional soot reaching the engine oil. This in turn will mean shorter drain intervals or using more expensive synthetic oils. Either way, oil costs will rise. But if the problems of EGR can be overcome in time, its use will allow more advanced injection timing, lessening stress on the oil.