摇臂式喷头喷嘴结构改进及水力性能试验研究

为了降低摇臂式喷头在工程应用中的运行成本、提高喷灌质量,本文针对8034D摇臂式喷头主、副喷嘴结构进行了优化改进,并研究了喷嘴结构改进后对喷头流量、径向水量分布和组合喷灌均匀度的影响。结果表明,主喷嘴内腔锥度角对喷头流量的影响呈显著水平,内腔锥度角越大,喷头流量越小;当工作压力相同时,改进副喷嘴结构对喷头流量的影响不大。随着测点与喷头水平距离的逐渐增加,不同内腔锥度角和圆柱段长度下的径向喷灌强度均呈递减趋势。组合2(1 mm#54°主喷嘴与改进后副喷嘴组合)在4种组合方式中的喷灌均匀性较好,其在喷头正方形布置下7种组合间距(12 m×12 m～18 m×18 m)时的平均喷灌均匀系数为87.8%,其中17 m×17 m时的喷灌均匀系数峰值达到89.3%。综合考虑喷灌质量和经济性两方面,在实际工程设计时,建议8034D摇臂式喷头主、副喷嘴的组合方式优先选用组合2,喷头工作压力设置为250 kPa,且组合间距以17 m×17 m为宜。

Optimization of nozzle structure and investigation on hydraulic performance of impact sprinkler

In order to reduce the operating cost of impact sprinkler in engineering application and improve the quality of sprinkler irrigation, this paper focused on the improvement of main and secondary nozzle structure of the 8034D impact sprinkler, and the effects of the improved nozzle structure on sprinkler flow rate, radial water distribution and the uniformity coefficient of combined sprinkler irrigation. The results showed that, conical angles of inner cavity had a significant effect on sprinkler flow rate, the larger the conical angles of inner cavity, the smaller the sprinkler flow rate. At the same working pressure, the im-proved secondary nozzle structure had little effect on the sprinkler flow rate. With the increasing of the hori-zontal distance between the measured point and the sprinkler, the radial water application rate at different conical angles of inner cavity and the cylinder lengths was decreasing. The uniformity of sprinkler irrigation of the combination 2 were better among the four combinations, the average uniformity coefficient of seven kinds of combined space in a square arrangement of sprinkler was 87.8%, and the peak of the uniformity coefficient reached 89.3% when the sprinkler spacing was 17m×17m. Taking the irrigation quality and cost into account, the main and secondary nozzles of the 8034D impact sprinkler choosing combination 2 at the sprinkler operating pressure of 250 kPa and the sprinkler spacing of 17m×17m.