Search Results

The emissions limits of CO2 for vehicles are becoming more stringent with the aim of reducing greenhouse gas emissions and improve fuel economy. The New European Driving Cycle (NEDC) is adopted to measure emissions for all new internal combustion engines in the European Union, and it is performed on cold vehicle, starting at a temperature of 22°C ± 2°C. Consequently, the cold-start efficiency of internal combustion engine is becoming of predominant interest. Since at cold start the lubricant oil viscosity is higher than at the target operating temperature, the consequently higher energy losses due to increased frictions can substantially affect the emission cycle results in terms of fuel consumption and CO2 emissions. A suitable thermal management system, such as an exhaust-to-oil heat exchanger, could help to raise the oil temperature more quickly.

The increase in the fuel price and more stringent regulations on greenhouse gases (CO2) make the engine compression ignition technology even more attractive in the context of internal combustion engines. This is because the modern turbocharged direct injection engines, with the common rail fuel system, are characterized by high combustion efficiency and power density, that make them particularly suitable both for applications on and off road. On the other hand, the compression ignition engines are subject to a heavy technological developments to meet the more stringent regulations on emissions of exhaust pollutants, especially PM and NOx. The adopted technologies have two main approaches, on the combustion and on the exhaust gas aftertreatment. The measures applied for combustion can reduce emissions, but with the risk of penalizing the other engine performances, such as noise, power output and fuel consumption.

International regulations are challenging automotive industry to develop more efficient systems for reducing diesel engines NOx emissions. Selective Catalytic Reduction systems may be a concrete solution, in fact SCR systems are already on the market, firstly developed for heavy duty diesel engine applications, and now it is beginning the spreading to light automotive applications. The urea-water solution dosing module may be subjected to strong heat transfer, so an efficient heat dissipation is crucial step to avoid injector's severe damages, as deformations of internal components or solenoid's fault. To have a system less complex and consequently less expensive, the dosing module air cooling should be preferred to liquid cooling. Obtain an efficient heat dissipation from the injector holder unit can represent a hard task: consequently dosing module design must be careful.