渐扩切向槽角度对低压燃油雾化喷嘴流动特性影响的数值研究

油枪点火与助燃在燃煤锅炉上应用较为普遍，但在应用中油喷嘴雾化所需的压力较高（2.0~2.5MPa），耗油量较大，使整个油系统的维护工作量增大，并影响运行的经济性。为减小运行压力，文中提出有渐扩切向槽式旋流雾化油喷嘴，建立了有渐扩切向槽旋流雾化喷嘴的三维流动数学模型，采用k-e /RNG模型和SIMPLE方法数值模拟了有渐扩切向槽偏转角的低压燃油喷嘴的流动特性，并对不同渐扩切向槽角度q时的喷嘴流动特性进行了比较，结果表明：渐扩切向槽的偏转角q大小对其流动特性影响较大，偏转角q不能为负值，因其能量损失较大；当渐扩角度q=6°时，其能量损失最小，喷嘴内轻柴油流动刚好形成实心的锥体，喷嘴回流刚好消失，此后，随着q的增加，能量损失也增加；切向槽只要存在渐扩角度，其能量损失均小于无渐扩(缩)角度的情况，切向槽外扩角度(正值)的能量损失小于切向槽内扩角度。

Numerical Investigation on Flow Characteristic of Oil Atomized Nozzle with Micro-Expanded Tangent Channel at Lower Pressure

Ignition and combustion-supporting have been widely applied in the site with oil gun, but its operation pressure is higher(2.0-2.5MPa), and oil costing is bigger, the maintenance of the oil system is inconvenience and lower operation economy. To conquer the faults, the oil atomized nozzle with micro-expand channel is put forward, and then the 3-D mathematical models for oil rotary atomized nozzle with micro-expanded tangent channel at low pressure are presented, the k-e /RNG model and the SIMPLE method is adopted, the flow characteristic is gotten in different micro-expand channel angle(q):The angle(q) of the micro-expanded tangent channel plays an important role for the fluid characteristics, if q<0, the energy loss would be increased obviously. The least energy loss is existed while q=6°, and the circumfluence at the exit of the nozzle isn't exactly formed with q=6°, the solid cone in nozzle are formed exactly, If q≥6°, the energy loss would be increased with increasing q. The energy loss of oil rotary atomized nozzle with micro-expanded tangent channel is lower than that of without of micro-expanded tangent channel. The energy loss for the outside micro expanded channel is lower than that of the inside micro expanded channel.