Search Results

In this paper, a new turbulent-film type direct injection combustion system with reentrant multi - lobe combustion chamber and helical intake port to form intake swirl, squish, macro and micro turbulence and to realize the combustion process with mainly the space atomization and partly the film evaporation. The test results indicated are: increasing the power output, lowering the fuel consumption, decreasing the peak pressure and the rate of pressure rise and improving the Nox emissions. The design, experiment and theoretical analysis of this system are presented and a brilliant prospect is expected.

The film-space atomization combustion has been implemented in a direct injection, no inlet swirl and shallow ω type combustion chamber and a new combustion system, namely, the ω7 film-space atomization combustion system, has been developed which has been substituted for the traditional space atomization combustion system in a 6E150C diesel engine. As a result, the performance of this engine has been improved substantially. The thickness and its variation process of the fuel film spread on the combustion chamber wall of the piston crown have been measured in a normal operating engine equipped with the ω7 system at different conditions by means of a set of apparatus. The experimental results show that the fuel film area and volume can be automatically adjusted as the engine load changes, which, it is believed, makes the ω7 system attain both the lower specific fuel consumption and the lower peak pressure at all load and speed ranges.

A multi-zone mathematical model of film-space atomization combustion in direct injection diesel engines is presented, which consists of a submodel of evaporation and combustion of the fuel film sprayed on the combustion chamber wall and a submodel of atomization combustion of the fuel sprayed in combustion chamber space. The fuel film sprayed on the combustion chamber wall is divided into many subzones and the fuel sprayed in the combustion chamber space is considered as one subzone. The submodels are combined through the conservation of the energy and mass in the full film-space atomization combustion system, and an overall system of differential equations are given. The initial and boundary conditions are resulted from the experiments on diesel engines. By means of the model, the film-space atomization combustion processes in 6E150 diesel engine are investigated quantitatively. The comparison between the calculated results of the model and the experimental data is satisfactory.