In recent days there is much talk of diesel emissions and NOx. A few days ago you were explaining why it was so important to reduce NOx emissions, with a dossier in which we told you about the risks to health that generates this pollutant gas. We know that Volkswagen will have to provide technical solutions for engines TDI affected by the fraud that was detected in the United States. Solutions which, after all, have already been high for manufacturers in recent years, while diesel has had to face a reduction in NOx emissions sufficiently important to overcome regulations, tighter against this pollutant such as Euro VI. That’s why we set 4 Strategies to overcome NOx, to a greater or lesser extent help Volkswagen in its solution to the crisis of TDI .
1. Software settings.
The presence of a software engine TDI Volkswagen that “trucase” performance in the test, for a figure of absolute NOx emissions obviously met a need, to reduce these emissions to meet US regulations – and apparently in Europe, most likely also to meet European standards. That means that the problem can not be corrected only by removing the software from which much has been said.
There is a possibility that other software settings, which perhaps could involve collateral damage, such as loss of benefits or a higher consumption, could be enough to make these engines comply with international regulations emissions legally, without tricks.
The big problem is that still do not know how this solution can affect the performance or consumption of diesel affected . Everything we say at this point would at least speculate. NOx emissions depend not always as obvious factors, such as CO2 , such as seeking more favorable long to suit the stages of development approval cycles. So open up some possibilities:
- That some engines get “legalized” by some settings in the software. Without their consumption figures or their services look very affected.
- than other engines require a stricter software settings that cause the loss of benefits or increase in consumption, is more obvious. These days we speak of some “evidence” of third parties have tried to quantify the loss of power that would remove the software (See: How much power will lose TDI Volkswagen rigged without the “defeat device” This video is the answer you expect?)
- than other engines require technical solutions that go beyond software, necessitating the use of more complex devices or catalysts require special maintenance. Which brings us to the next point.
2. NOx traps.
A common solution, which is more than enough in small displacement diesel engines and vehicles for small or compact size, is to use a device known in the industry as the NOx trap . Manufacturers have designed systems that are able to “catch” literally NOx through the use of precious metals . These systems, called NOx traps also have their cost and require regeneration process, which usually occur automatically, in which the temperature is raised to end the NOx once and for all. His philosophy is similar to that of particle filters that both have to talk in recent years.
In line with the Volkswagen affair, there are fears that meet the requirements for approval in Europe and the United States, NOx traps TDI affected have to be replaced by more advanced systems, and even resort to another alternative, the AdBlue.
Manufacturers have already been found to this problem to certify their diesel engines under the Euro VI emission regulations. In some cases they have been able get by using a NOx trap, but in many others, when the trap was not enough, had to resort to Adblue system.
For some time we have been talking at length about this system, previously only knew for use in commercial vehicles and transportation, and the occasional tourist, and for some years has been increasing its presence to become commonplace in the new wave of Euro VI diesel engines .
At that time the NOx trap is not enough to catch and limit NOx emissions of a car, it is necessary to use a sophisticated system like this, that breaks the NOx molecule by using a web-based solution urea. We will not go too much into detail about how it works, since we have already developed a fairly comprehensive guide AdBlue, which I refer to complete this information.
AdBlue type devices have different problems, beginning at cost. Also require maintenance at least refill your tank every so often . Some manufacturers have made AdBlue refills under normal circumstances coincide with periods of maintenance and replacement of oil and filters of the car, so that – if there is no problem – the customer need not worry about it. Unfortunately, not all vehicles are marketed and used AdBlue work that way. Many require recharging between maintenance periods, that will lead to enough to require this workshop or learn how we proceed with this.
4. The domain of combustion.
Another technique, no less complex, but probably more interesting, it relies on a “clean” combustion, combustion in which fewer particles are generated and in the issue that concerns us, the less NOx. It is possible that the industry should have put all their attention on this aspect, and not only in diesel, before adding complexity to their engines with turbos, systems stop-start, anti-pollution systems, and so on. But it is also true that research and development efforts requiring that domain of combustion are very high.
In any case, we are pleased to hear that there is such remarkable and noteworthy as the new generation of diesel engines Mazda cases. The Japanese were using their diesel AdBlue years (if I remember correctly, the first model with AdBlue I had occasion to drive long was the Mazda CX-7, matching the restyle which introduced the diesel engine in Europe). But the work with new diesel SKYACTIV -D , with an unusually low compression ratio for a diesel, make NOx emissions are low enough not to require more advanced devices in order to synthesize this pollutant . And that even taking into account that some of these engines have important displacements above 2 liters, and are potent.
Even more interesting, almost utopian, the Mazda scenario arises in the near future and the progress already developed at its technical centers. Mazda says they are working in line with an adiabatic or rather, quasi-adiabatic with a thermal efficiency close to ideal motor.
Gallery : Dossier: Emissions of NOx in 7 questions and answers, why is this so dangerous pollutant? Why is so severe the Volkswagen case?
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