Description: Das Projekt "Beseitigung materialabhaengiger Probleme bei der NOx-Verringerung bei Dieselmotoren mit grossem Hubraum durch Einspritzung eines Reduktionsmittels in den Zylinder" wird vom Umweltbundesamt gefördert und von MAN B&W Diesel AG durchgeführt. General Information: For reduction of NOx from large Diesel engines in ships power stations the selective catalytic reduction (SCR) is assigned technology. It has several severe disadvantages, economically and technically as well as ecologically. To overcome this a package of engine modifications including reducing agent injection and exhaust gas recirculation has been developed which, however, is not yet applicable because of very high wear of engine components. It is the aim of this project to remove this obstacle by the application of new materials. The main objectives for this purpose are the following: A) Getting further insight into the mechanisms underlying the exorbitant wear phenomena observed in connection with reducing agent injection so as to improve the basis on which the questions of materials can be defined. B) Finding a compromise between the NOx reduction and the wear involved. C) Adaptation of the engine and the reducing agent injection system, in terms of design and materials used, to the higher corrosive attack, relying on the know-how as per A). D) Testing of filtering systems that are capable of cleaning ash-bearing exhaust gases and that could be for filtering the gases in the exhaust gas recycling system. A reduction of additional costs for NOx reduction of 30 per cent is expected. Achievements: The main results can be summarized as follows: Materials were identified which allow the design of injection nozzles for urea solution under high temperatures and pressures. State-of-the-art common-rail injectors for diesel fuel-injection are not suited for injection of water or reducing-agent-solution due to their high leakage rates and wear. Standard diesel injection nozzles can successfully be operated with water if a sufficient amount of a suitable lubricant is added to the water, - injection pressure is not too high, - the nozzle is not used as a control device as is the case with certain common rail injectors. The wear characteristics can be improved by suitable materials. The NOx-reduction rate achieved with RAI is not sufficient. RAI is thus not economic. A theoretical model for RAI has been developed which is able to explain the failure of this method. With the combination of DWI + EGR + FWE it is possible to reduce NOx by more than 80 per cent while keeping reasonable smoke limits. A filter system has been developed which is able to clean exhaust gases of diesel engines operated on HFO with an efficiency of 98 per cent with respect to SOx and 80 per cent with respect to particulates. This filtering efficiency is however not sufficient to make possible the long term EGR operation of an engine burning HFO. Materials for piston rings and cylinder liner have been developed which are able to provide state-of-the-art or even better wear results in an engine running with DWI.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Dieselkraftstoff ? Harnstoff ? Wasserwiederverwendung ? Abgasfilter ? Schwefeloxid ? NOx-Minderung ? Dieselmotor ? Reduktionsmittel ? Schmierstoff ? Temperaturverteilung ? Altgerät ? Main ? Abrieb ? Brand ? Filter ? Gasfiltration ? Abgasrückführung ? Katalyse ? Rauch ? Stickoxide ? Verbrennung ? Verbrennungsmotor ? Verfahrenskombination ? Verfahrensoptimierung ? Korrosion ? SCR-Verfahren ? Reinigungsleistung ? Schiff ? Entstickung ? Abgasreinigung ? Stand der Technik ? Antriebstechnik ? Betriebskosten ? Verbrennungsrückstand ? Kostensenkung ? Verfahrenstechnik ? Kreislaufsystem ? Wirtschaftlichkeit ? Meerestechnik ? Kraftwerk ? Wasser ? Reinigungsverfahren ? Ökologische Wirksamkeit ? Schadstoffminderung ? Umweltfreundliche Technologie ? Verpackung ? Leckage ? Technische Aspekte ? Neuartige Materialien ? Produktdesign ? Substitutionseffekt ? Reduktion [chemisch] ? aerospace technology ? industrial manufacture ? material technology ? Zerstäubung ?
Region: Bayern
Bounding box: 12.53381° .. 12.53381° x 47.795° .. 47.795°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1994-06-01 - 1997-06-30
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