Provning av oreglerade emissioner i tunga metangasdrivna fordon

På uppdrag av SGC (samt medfinansiärer) har AVL MTC mätt emissioner från tre tunga fordon då de körts på chassidynamometer. För provningen användes en för chassidynamometerprov modifierad version av provcykeln ”Worldwide Harmonized Transient Cycle” (WHTC) vilken används vid certifiering av motorer till tunga fordon. Benämningen på den modifierade provcykeln är Worldwide Harmonized Vehicle Cycle (WHVC). Fordon nummer 1var en CNG (Compressed Natural Gas) driven citybuss godkänd enligt emissionsstandarden EEV(Enhanced Environmental friendly Vehicle). Förbränningsprincipen för motorn var sk stökiometrisk/”lean mix", dvs den växlade mellan stökiometrisk och mager förbränning. Fordonet var utrustat med en trevägskatalysator. Bränslet som användes vid provningen var CNG från fordonets egen tank, tankad på vanlig tankstation. Fordon nummer 2 var en lastbil (för fjärrtransport) ombyggd till sk Dual Fuel drift/metandiesel, dvs motorn drevs med en varierande blandning mellan diesel och metangas. Lastbilen var godkänd enligt emissionsstandard Euro V i sin ursprungliga form (diesel bränsle). Då certifieringsmetod för denna typ av fordon i dagsläget saknas, utfärdar Transportstyrelsen dispenser till tillverkaren vilket möjliggör registrering av fordonen. Enligt denna dispens ska fordonet uppfylla emissionsstandard Euro V. Fordonet var utrustat med en oxidationskatalysator och ett SCR-system. Bränslet som användes vid provningen av detta fordon var Mk1 (utan HVO-tillsats) samt LBG (Liquefied Bio Gas). Både Mk1 diesel och LBG tankades av Volvo. Bränslespecifikationer för LBG finns bifogade i appendix. Fordon nr 3 var en CNG driven buss av emissionsstandard EEV. Förbränningsprincipen för motorn var sk ”lean-burn”, dvs drevs med luftöverskott. Fordonet var utrustat med en oxidationskatalysator. Bränslet som användes vid provningen var CNG från fordonets egen tank, tankad på vanlig tankstation.

On behalf of the SGC (and co-financiers) AVL MTC has measured emissions from three heavy duty vehicles running on a chassis dynamometer. The test cycle used for the dynamometer testing was the Worldwide Harmonized Transient Cycle for certification of Heavy Duty Engines (WHTC) modified to be used on chassis dynamometers, Worldwide Harmonized Vehicle Cycle (WHVC). Vehicle number 1 was a CNG (Compressed Natural Gas) fuelled city bus approved according to emission standard EEV (Enhanced Environmental friendly Vehicle). The combustion principle of the engine was so called stoichiometric / "lean mix", i.e. alternating between stoichiometric and lean combustion. The vehicle was equipped with a three-way catalytic converter. The fuel used in the test was CNG from the tank of the vehicle which was filled up on a commercial fuelling station. Vehicle number 2 was a (long-haul) truck converted to so-called Diesel Dual Fuel operation/methane-diesel, i.e. the engine was operating with a continuously varying mixture of diesel and methane gas. The truck was approved according to emission standards Euro V in its’ original shape (diesel fuelled). Since a certification method for this type of engine currently is missing, the Swedish Transport Agency issues a waiver to the manufacturers which make it possible to register the vehicles. According to this waiver, the engine shall comply with the emission standard Euro V. The vehicle was equipped with a diesel oxidation catalyst and a SCR system. The fuel used in the testing of this vehicle was Mk1 (without HVO (Hydrotreated Vegetable Oil) additive) and LBG (Liquefied Bio Gas). Both Mk1 diesel and LBG was supplied by Volvo. Fuel specification for LBG can be found in the appendix. Vehicle number 3 was a CNG fuelled city bus approved according to emission standard EEV. The combustion principle of the engine was so called "lean-burn", i.e. operating with air excess. The vehicle was equipped with a diesel oxidation catalyst. The fuel used in the test was CNG from the tank of the vehicle which was filled up on a commercial fuelling station.