The use of the mild hybrid system in vehicles with regard to exhaust emissions and their environmental impact

Abstract

Pollution of the environment is a global phenomenon. The lack of specific actions to reduce environmental pollution can lead to an increase in the average temperature of the Earth's air and to global consequences. One of the important sectors affecting environmental pollution is transport, including road transport. Currently, intensive legislative and construction works are underway to reduce the emission of harmful substances from road transport. Meeting the requirements imposed by the European Union makes it necessary not only to make structural changes to combustion units or exhaust aftertreatment systems, but also to use additional systems supporting the operation of the main engine. This group includes, among others, Mild Hybrid propulsion systems and classic hybrid systems. Their application is to affect not only the possibility of reducing the swept volume of a combustion unit, while maintaining its operational parameters, but also to reduce the emission of harmful substances of exhaust gases. The conducted research and its analysis indicate the legitimacy of using a newer vehicle equipped with a modern propulsion system, i.e. Mild Hybrid, in real conditions. In the case of toxic emissions of exhaust gases, a difference in emissions of individual components is noticeable, depending on the chosen driving mode. However, it is worth mentioning the difference in the emission of nitrogen oxides and the number of particulate matters. Their emission is reduced in relation to a vehicle using a classic powertrain. The use of a modern propulsion system also improves reliability. The tested Mild Hybrid vehicle does not use a conventional alternator and starter. This eliminates the elements that are prone to damage in prolonged operation. This is an unquestionable advantage when taking into account the operation of the vehicle.