Emissions and Consumption Reductions in Heavy-Duty Vehicles by Means Optimized Engines and Fuel Systems

Nowadays, LNG (Liquefied Natural Gas) represents a feasible and profitable alternative to diesel as a viable fuel due to important reductions in emissions and consumption, as well as for decreasing our dependence on oil. Currently, the efforts to obtain lower emission levels in internal combustion engines are mainly focused on the improvement of catalyst technologies. Nevertheless, a significant reduction in emissions and consumption in heavy-duty vehicles could be achieved by means of the adjustment of the vehicle components (engines and fuel systems) to the specific task for which they were designed.

In this way, both the engines and the fuel systems may be optimized for both the consumption and the emissions by means of several factors: an exhaustive study of the cycles to be performed, the vehicle weight, the speed and necessary accelerations in the vehicles, as well as the use of simulation tools. With this aim, three different cases dealing with the public transport have been analyzed: (i) a bus optimized to perform an urban cycle, (ii) a bus to carry out an inter-urban cycle (iii) and finally, a bus optimized for a mixed cycle. From the obtained results, we conclude that significant reductions in emissions and consumption can be achieved in these vehicles thanks to an optimized design in terms of the cycle and the specific work each vehicle develops.