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A heavy-duty vehicle (HDV) module of the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREETTM) model has been developed at Argonne National Laboratory. The fuel-cycle GREET model has been published extensively and contains data on fuel-cycles and vehicle operation of light-duty vehicles. The addition of the HDV module to the GREET model allows for well-to-wheel (WTW) analyses of heavy-duty advanced technology and alternative fuel vehicles (AFVs), which has been lacking in the literature. WTW analyses of HDVs becomes increasingly important to understand the fuel consumption and greenhouse gas (GHG) emissions impacts of newly enacted and future HDV regulations from the Environmental Protection Agency and the Department of Transportation’s National Highway Traffic Safety Administration.

An applicable and comprehensive control strategy of a natural gas/diesel dual fuel engine is presented in this paper. The dual fuel engine is converted from a conventional mechanical pump, turbo charged, heavy duty diesel engine. In the dual fuel mode, the pedal position is explained as demanded total fuel quantity, the quantity of pilot diesel and natural gas are calculated in order to provide the equal energy with the original diesel engine at the same operation condition, the proportion of the natural gas is primarily determined by the load rate and the speed of the engine. When the engine is working under light or moderate load, the intake air is throttled in order to improve the brake mean effective pressure and reduce the hydrocarbon emissions of the dual fuel engine, according to target excess air ratio and the quantities of the two fuels, the desired air mass per cycle can be obtained.

The present concern in the reduction of CO2 emissions occasioned by heavy duty trucks is leading to a technological evolution, among others, in powertrain electrification. Towards this objective, the EU has funded the project GASTone targeting the development of a new powertrain concept based on the energy recovery from the exhaust gases and kinetic losses in order to make possible the electrification of the main auxiliaries. This new concept will follow a cascade approach in which the exhaust gases energy will be recovered by the integration of an advanced thermoelectric generator followed by a turbo-generator. This system will be combined with a smart kinetic energy recovery device which will recover the energy losses in the deceleration periods of the vehicle. The recovered energy will be used in the electrified auxiliaries.

This article presents a study related to application of pre-chamber ignition system in heavy duty natural gas engine which, as previously shown by the authors, can extend the limit of fuel-lean combustion and hence improve fuel efficiency and reduce emissions. A previous study about the effect of pre-chamber volume and nozzle diameter on a single cylinder 2 liter truck-size engine resulted in recommendations for optimal pre-chamber geometry settings. The current study is to determine the dependency of those settings on the engine size. For this study, experiments are performed on a single cylinder 9 liter large bore marine engine with similar pre-chamber geometry and a test matrix of similar and scaled pre-chamber volume and nozzle diameter settings. The effect of these variations on main chamber ignition and the following combustion is studied to understand the scalability aspects of pre-chamber ignition. Indicated efficiency and engine-out emission data is also presented.

We assessed gaseous and particulate matter (PM) emissions from a current technology stoichiometric natural gas waste hauler equipped with a 2011 model year 8.9L Cummins Westport ISL-G engine with cooled exhaust gas recirculation (EGR) and three-way catalyst (TWC). Testing was performed on five fuels with varying Wobbe and methane numbers over the William H. Martin Refuse Truck Cycle. The results showed lower nitrogen oxide (NOx) emissions for the low methane fuels (i.e., natural gas fuels with a relatively low methane content) for the transport and curbside cycles. Total hydrocarbon (THC) and methane (CH4) emissions did not show any consistent fuel trends. Non-methane hydrocarbon (NMHC) emissions showed a trend of higher emissions for the fuels containing higher levels of NMHCs. Carbon monoxide (CO) emissions showed a trend of higher emissions for the low methane fuels.