Turbocharging Concepts

Introduction

The enacted average CO₂ emission for new passenger vehicles in Europe is limited to 120 g/km from 2012 (65% produced vehicles) to 2015 (100%). This emission limit is reduced to the ambitious long-term target of 95 g/km from 2020. Additionally, the average CO₂ emission limit for new light-duty commercial vehicles is 175 g/km from 2014 (70% manufactured vehicles) to 2017 (100%); and it is reduced to 147 g/km (ambitious long-term target) from 2020. To reduce carbon dioxide (CO₂) and nitrogen oxides (NO_x) exhausted by passenger and commercial vehicles and to improve the fuel consumption of the engines, we have already carried out many measures, e.g. high-pressure direct injection (HPDI), exhaust gas recirculation (EGR), variable valve train (VVT), variable compression (VC), and hybrid techniques [3]. Two other important aspects are downsizing of engines by reducing the number of cylinders or volumetric size of cylinders, and turbocharging. Engines with less number of cylinders or small cylinder volumes induce less friction power between the pistons and cylinders. Additionally, the total weight of the vehicle is also reduced due to small engines, leading to less driving friction. Evidently, small engines needs less fuel consumption; in turn, they produce less engine power. Small engines consume less fuel and therefore produce less carbon dioxide (CO₂) and as well as nitrogen oxides (NO_x). In the point of view of energy and air pollution, they have done a good job to sustain our energy resources and to keep the environment less polluted and clean.