Abstract
Keywords:
Intake air heating, pollutant emissions, engine warm-up, MVEG cycle
Abstract:
Intake air heating is currently under evaluation as a possible alternative to glow plugs for cold start assistance of automotive DI Diesel engines. In addition to this function, air heating can also be suitable for the reduction of pollutant emissions and the control of combustion noise during the warm-up of this type of engines. The aim of this paper deals with the evaluation of the potential of the air heating technology for the reduction of the pollutant emissions of a small turbocharged DI Diesel engine at warming-up conditions. With this purpose the European homologation tests for emissions measurements (MVEG cycle) have been performed with glow plugs and an air heater located at the inlet of the intake manifold. The benefits of the air heating technology have been evaluated in comparison with the results obtained with glow plugs which correspond to the standard configuration of the engine. The potential of the air heating was preliminarily evaluated through tests with constant heating in a part of the UDC phase. These preliminary results have induced to the definition of a dynamic strategy for air heating which has allowed to HC, CO and NOx reductions of 13%, 5% and 3% respectively without penalty in fuel consumption.