20PY_(2)摇臂喷头掺气情况下的低压喷灌效果

Effect on combination irrigation of low pressure 20PY_(2) impact sprinkler with and without aeration

20PY_(2)掺气喷头是以20PY_(2)摇臂喷头结构为基础,引入气液两相流理论得到的一种喷头.以20PY_(2)掺气喷头为研究对象,研究其低压下的喷灌效果,并对比摇臂喷头的喷灌效果.试验评价指标:平均喷灌强度、蒸发漂移量、喷灌均匀系数及分布均匀系数;变量:工作压力和组合间距.试验结果表明:与摇臂喷头相比,掺气喷头的射程变化不大,但掺气喷头的平均喷灌强度随工作压力递增,随着组合间距递减;低压下,掺气喷头在风速为1 m/s时的蒸发漂移量约为5%,其组合喷灌的最佳工作压力和组合间距分别为300 kPa和1.1R.掺气喷头喷灌强度峰值与谷值的阶梯性较好,同等数量测点的喷灌强度峰值区间和谷值区间平均值趋向于平均喷灌强度,峰值区间和谷值区间喷灌强度在灌溉总强度中的占比分别低于和高于摇臂喷头.因此,喷灌效果优于摇臂喷头.

Based on the structure of the 20PY_(2) impact sprinkler,the principle of gas-liquid two-phase jet spray was applied to procedure a 20PY_(2) aeration impact sprinkler.At the low pressure,the combination irrigation effect of 20PY_(2) aeration impact sprinkler was studied and compared with 20PY_(2) impact sprinkler.The evaluation index was included the average irrigation intensity,evaporation drift values,combination uniformity coefficient and distribution uniformity coefficient.Meanwhile,the variable was included work pressure and combination distance.The experiment results show that:compared with the impact sprinkler,the range of the aeration impact sprinkler has little change,but the average sprinkler intensity of the aeration impact sprinkler increases with the increase of working pressure and decreases with the increase of combined distance.At the low pressure,the evaporation and drift value of aeration impact sprinkler at the wind speed of 1 m/s is about 5%,and the optimal working pressure and the combination distance of its combination irrigation are 300 kPa and 1.1R,respectively.Aeration impact sprinkler have a better gradient between the peak and valley values of irrigation intensity.The average value of the peak interval and valley interval of the same number of measurement points tends to be the average irrigation intensity.The proportion of the peak interval and valley interval in the total irrigation intensity is lower and higher than that of the impact sprinkler.Therefore,the sprinkling irrigation effect of aeration sprinkler is superior to that of impact sprinklers.