Analysis of elliptical diesel nozzle spray dynamics using a one-way coupled spray model

The elliptical nozzle has the potential ability to increase the air-fuel mixture quality. A one-way coupled spray model and Homogenous Relaxation Model (HRM) was adopted to investigate the spray behaviors and the air-fuel mixture progress in real diesel combustion chamber with the application of elliptical and circular diesel nozzle. The results indicated that the spray cone angle and the air entrainment mass of elliptical nozzle were larger than that of the circular nozzle, while the spray penetration of the elliptical nozzle which the aspect ratio is 1.5 and 2 was shortened by 11% and 8.3% as compared to circular spray respectively. Also, the air entrainment mass of the elliptical spray with a ratio of 1.5 and 2 increased by 60% and 35% as compared with circular spray respectively. Furthermore, the partial equivalent ratio and the high concentration area in the cylinder is reduced for elliptical nozzle, and the air-fuel mixture is more uniform. The fuel evaporation rate of elliptical spray is always higher than that of the circular spray.

Improving the efficiency of liquid fuel boiler plants

The issues of saving fuel and energy resources, as well as improving the equipment efficiency, are of great importancei n all sectors and especially in the energy sector, the main fuelconsuming industry. Improving of the boiler plants efficiency and is currently an urgent issue. Organizational and technical measures to improve technological processes are being developed at each station. The article discusses several ways to improve the boiler plants efficiency using liquid fuel. Industrial tests of the diesel nozzle cleaner in the boiler plant were carried out, which led to the following results: - received fuel consumption savings of 8.67%. At the same time, the amount of heat transferred to the LTC-4 network increased by 5.86%. - the specific indicator of fuel consumption (the ratio of diesel fuel consumption to the amount of heat transferred, kg / Gcal) decreased by 12.57%, and also at the same time as the efficiency of the boilers, the resource indicators of the boiler nozzles will increase, the time and the costs for the nozzles technical inspection will decrease.

Optical experiments of string cavitation in diesel injector tapered nozzles

Flow inside the diesel nozzle is crucial to spray, combustion, and emissions. This work aimed to improve the understanding of effects of internal fuel-flow on diesel spray, especially the special string cavitating flow. Optical experiments were employed for characterizing the formation of string cavitation inside the transparent scaled-up tapered diesel orifices. Simultaneously, the corresponding evolution of spray cone angles were obtained. Results show that there were two origins of the string cavitation, which were originated from inlet and outlet of the orifice, respectively. Moreover, there were two typical development processes of the string cavitation between hole and hole, which were defined as type-A and type-B string cavitation. Furthermore, effects of string cavitation were analyzed: it could trigger the geometry-induced cavitation and make a sharp increase of spray cone angle. Finally, the relationships between the occurrence regularity of string cavitation, the needle lift and the injection pressure were revealed by comparison of different needle lifts and different injection pressures.