Redesign of the Axial Cooling Fan for an Air-cooled Diesel Engine

As the power of air-cooled diesel engine increases, the problems of insufficient total pressure and flow rate of the cooling fan have become increasingly prominent. This study proposes a redesign strategy for the axial cooling fan of high-power air-cooled diesel engines to resolve severe overheating under rated operating condition. Firstly, the performance of the baseline fan is evaluated through the cooling system test, and the aerodynamic test as well as numerical simulation, resulting in a specific design target for the high-load fan. Subsequently, based on the assumption of constant twist velocity and axial outflow, the fan inlet negative pre-swirl angle is calculated. Then, the impeller and guide vane matching design for the high-load fan is completed based on the cascade design theory. The test results show that under the design condition, the total pressure and static pressure of the high-load fan reach ۵۴۳۹ Pa and ۳۲۵۷ Pa respectively, increasing by ۹۰% and ۷۹% compared to the baseline fan. The engine thermal balance experiment indicates that under the rated power, the high-load fan has reduced the cylinder temperature by ۱۵.۶ ℃, and obviously alleviated the overheating problem of the engine.

کلیدواژه ها:

Air-cooled diesel engine ، High-load cooling fan ، Negative pre-swirl guide vane ، Cascade design theory ، Total pressure and efficiency