There is no micro-explosion in the diesel engines fueled with emulsified fuel

According to the criterion of micro-explosion occurrence, a new viewpoint that micro-explosion may not occur in diesel engines is presented in this paper. The relationship among the diameter change of an emulsified fuel droplet, water and fuel evaporation rate is obtained from the multi-component control equations of the droplets. Because the evaporation rate of water is much more rapid than that of fuel, water will evaporate much quickly than fuel in this process, so the water is evaporated in advance, and at the same time large droplets change into small ones. This is in fact the main reason of combustion intensification for emulsified fuel. The investigators at home should notice that the fuel droplets used in the previous experiments were always droplets with big diameter (about d0⩾250 μm), which might be owing to the restriction of the experimental conditions. Micro-explosion does happen on such fuel droplets with big diameters, which has caused all the authors to think that micro-explosion would happen on all the droplets without exception. However, it cannot be used to explain what really happens in diesel engines. In our research, we have found that micro-explosion will not occur when the size of droplets is too small, and the same is case with diesel engines.