射流三通产生的高频压力脉冲对迷宫流道灌水器堵塞的影响

滴头堵塞是滴灌技术发展的主要障碍。为了分析75 kPa射流三通入口压力下形成的压力脉动对迷宫流道灌水器堵塞的影响。该研究以3个压力（恒定压力，射流三通左侧和右侧的脉动压力），采用因素组合，进行了滴灌系统迷宫流道灌水器堵塞试验研究，最后确定射流三通产生的高频压力脉冲与稳压对平均相对流量（Dra）和克里斯琴森均匀性系数（CU）的影响。结果表明，射流三通组的平均相对流量和克里斯琴森均匀性系数分别比普通三通组高10.8%～14.8%和21.1%～44.9%。3种浑水浓度下（0.5，1.0和1.5 g/L），对于普通三通组，在第16、11和7次灌溉运行之后，平均相对流量降低到74%，这被认为灌水器处于严重堵塞的状态。但是，对于射流三通左和右侧组，分别在第18、16、14、13、11和10次运行后，平均相对流量仍高于75%。高泥沙沉积物浓度（1.5 g/L）的平均相对流量和克里斯琴森均匀性系数与低和中泥沙沉积物浓度（0.5和1.0 g/L）的有显着差异（P<0.01）。高浓度（1.5 g/L）时堵塞的可能性迅速增加，但此浓度下射流三通较普通三通依然具有抗堵塞性能。总之，射流三通产生的高频压力脉冲具有稳定的防堵塞性能。建议使用射流三通代替滴灌系统中的普通三通，以防止灌水器堵塞。

Effects of high-frequency pressure pulse generated by a jet tee on the clogging of labyrinth emitter

Abstract: Emitter clogging is the key obstacle to the development of drip irrigation technology. For this reason, a jet tee was developed in this study. Taking three pressures (constant pressure, fluctuating pressure on the left and right sides of the jet tee.) and three turbid concentrations as factors, the experiment was carried out by using a complete combination of the test factors. A study of labyrinth emitter clogging was conducted to determine the effects of high-frequency pressure pulse generated by a jet tee versus constant pressure on the relative discharge of drip irrigation emitters (Dra) and the coefficient of uniformity (CU ). The results showed that the values of Dra and CU of the jet tee group were 10.8%-14.8% and 21.1%-44.9% higher than the ordinary tee group, respectively. At different muddy sediment concentrations (0.5, 1.0 and 1.5 g/L), for constant pressure groups, Dra decreased to 74% after the 16th, 11th and 7th irrigation run respectively and was considered as a severely blocked. However, for the left side of the jet tee, Dra was still higher than 75% after the 18th, 14th, and 11th run respectively. For the right side of the jet tee, Dra was still higher than 75% after the 16th, 13th, and 10th run respectively. It can be seen that high-frequency pressure pulse generated by a jet tee has stable anti-clogging performance. At the low (0.5 g/L) and the medium (1.0 g/L) concentrations of muddy water, the emitters did not easily clog. The Dra at the high muddy (1.5 g/L) sediment concentrations remained to decrease drastically. However, the Dra at the low muddy sediment concentrations remarkably decreased after the 12 th run. The Dra at the medium muddy sediment concentrations remarkably decreased after the 10th run. For pulse pressure group with high concentration, the Dra decreased to 76% after the 11th run. However, for pulse pressure group with the low and the medium concentration, the Dra was still above 92% after the 11th run. For pulse pressure group with the low and the medium concentration, the CU remained above 84% after the 12th run. However, for pulse pressure group with high concentration, the CU decreased below 80% after the 7th run. The Dra and CU of the high muddy sediment concentrations (1.5 g/L) differed significantly (P<0.01) from those of the low and medium muddy sediment concentrations (0.5 and 1.0 g/L). Under three muddy sediment concentrations, the possibility of clogging quickly increases at high muddy sediment concentrations (1.5 g/L). However, at this concentration, the jet tee was still more resistant to clogging than the ordinary tee. It is recommended that a jet tee be used in place of the ordinary tee in the drip irrigation system to prevent emitter clogging.