Hyundai Elantra

since 2000-2004 of release

Repair and car operation

Reduction of toxicity of the fulfilled gases

Formation of a fuel mix and combustion process

– pressure of injection;
– injection time;
– aerosol distribution (number of a spray, a profile of a sprayed stream, the direction of a sprayed stream);
– moment of injection of fuel;
– air movement;
– amount of air.

These factors influence allocation by the engine of harmful substances and fuel consumption. High temperatures of combustion and high levels of concentration of oxygen lead to increase in formation of NOx. Allocation of soot increases at reduction of amount of air and insufficient formation of a fuel mix.

Criteria of the engine

The configuration of the chamber of combustion and the channel of an air inlet can positively influence reduction of issue of the fulfilled gases. If air moving in the chamber of combustion is carefully coordinated with fuel jets and sprays that promotes effective mixing of air and fuel, complete combustion of the injected fuel is reached. Besides, positive effects of homogenization of a mix of air and the fulfilled gas cooled in a path of EGR are reached. Use of four valves on the cylinder and a turbokompressor with the turbine of variable geometry (VTG) also promotes reduction of toxicity of the fulfilled gases and increase of specific capacity.

Moment of injection of fuel

Reduction of temperature of combustion and delay of process of injection of fuel lead to reduction of the maintenance of NOx in the fulfilled gases. However, if these parameters are considerably reduced, the maintenance of HC in the fulfilled gases and fuel consumption, also as well as soot allocation increases at high loads of the engine.

If the moment of injection of fuel deviates only on 1 ° (a cranked shaft) from optimum value, the maintenance of NOx can increase for 5 %, in view of that on 2 ° (a cranked shaft) towards an advancing of the moment of injection can give a deviation to increase in pressure in engine cylinders to the 10th bar, and a deviation on 2 ° (the cranked shaft) towards delay can increase on 20 ° temperature of the fulfilled gases. Such high sensitivity demands limiting accuracy at adjustment of the moment of injection of fuel.

Fuel dispersion

Melkodispersnoye dispersion of fuel promotes effective mixing of air and fuel. It makes the significant contribution to reduction of allocation of soot and HC. The high pressure of injection and an optimum geometrical configuration of an opening of a spray lead to good dispersion of fuel.

For an exception of emergence of a visible exit of soot the amount of injected fuel should be limited according to amount of air arriving in the engine. It demands supply of superfluous air, at least, on 10... 40 % (the X-th =1,1... 1,4). After closing of a needle of a spray the fuel which has remained in an opening of a spray, evaporates and leads to increase in allocation of HC. It means that such harmful volumes should be minimized.