王新坤, 薛子龙, 肖思强, 樊二东, 徐胜荣, 王轩, 张晨曦. 支毛管安装射流三通的滴灌系统水力性能研究[J]. 农业工程学报, 2019, 35(8): 134-139. DOI: 10.11975/j.issn.1002-6819.2019.08.016
    引用本文: 王新坤, 薛子龙, 肖思强, 樊二东, 徐胜荣, 王轩, 张晨曦. 支毛管安装射流三通的滴灌系统水力性能研究[J]. 农业工程学报, 2019, 35(8): 134-139. DOI: 10.11975/j.issn.1002-6819.2019.08.016
    Wang Xinkun, Xue Zilong, Xiao Siqiang, Fan Erdong, Xu Shengrong, Wang Xuan, Zhang Chenxi. Hydraulic performance of drip irrigation system with branch and lateral pipes installed jet-pulse tee[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(8): 134-139. DOI: 10.11975/j.issn.1002-6819.2019.08.016
    Citation: Wang Xinkun, Xue Zilong, Xiao Siqiang, Fan Erdong, Xu Shengrong, Wang Xuan, Zhang Chenxi. Hydraulic performance of drip irrigation system with branch and lateral pipes installed jet-pulse tee[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(8): 134-139. DOI: 10.11975/j.issn.1002-6819.2019.08.016

    支毛管安装射流三通的滴灌系统水力性能研究

    Hydraulic performance of drip irrigation system with branch and lateral pipes installed jet-pulse tee

    • 摘要: 为分析脉冲水流对滴灌系统水力性能的影响规律,该文基于射流附壁和切换原理设计了一种支管射流三通,并与毛管射流三通开展组合试验。在毛管铺设长度为60 m,4种支管三通进口水头(9.5、12、14、15.5 m)条件下,研究支毛管安装射流三通或普通三通时灌水小区的灌水均匀度、脉冲频率与水头损失变化规律,并建立描述支管射流三通出口流量和压力的拟合关系式。结果表明,当支毛管三通均采用射流三通时,支毛管中均为间歇性脉冲水流,脉冲频率随支管进口水头增加而递增;毛管滴头流量在1.2~2.2 L/h之间,沿程水头损失在0.9~1.6 m之间;灌水均匀性系数在95.88%~98.56%之间,流量偏差率在8.35%~15.14%之间,灌水均匀度最高。根据研究结果,确定了灌水小区中支毛管三通的最优组合方式,可为射流技术在脉冲滴灌系统的研究、开发与应用提供理论依据。

       

      Abstract: Abstract: Drip irrigation has the problems of easy blockage and low irrigation uniformity under low head (less than 10 m). Pulse drip irrigation technology can generate periodic and turbulent pulsed flow, which is beneficial to improve the anti-blockage ability and irrigation uniformity of the emitter. In order to analyze the influence of pulsed flow on the hydraulic performance of drip irrigation system, a branch jet-pulse tee was designed based on the principle of wall attachment and switching of jet, and a combined test with lateral jet-pulse tee was carried out. A total 4 irrigation districts were constructed according to different combinations, of which the branch and lateral pipe tees of No. I irrigation district were both jet-pulse tees; in No.II irrigation district, the branch pipe was jet-pulse tee and the lateral pipe was ordinary jet tee; in No. III irrigation district, the branch pipe was ordinary jet tee and the lateral pipe was jet-pulse tee; and the branch and lateral pipe tees of No. IV irrigation district were both ordinary jet tees. In irrigation district, the length of lateral pipe was 60 m, and the inlet head of branch tee was set to 9.5, 12, 14 and 15.5 m, respectively. Turbine flowmeter was installed at branch pipe tee outlet and lateral pipe tee inlet to record branch pipe tee outlet flow rate and lateral pipe tee inlet flow rate, respectively. The flow rate was the difference between the initial value and the final value in the flowmeter test. The high-speed camera captured the oscillation of pressure gauge pointer of lateral jet-pulse tee outlet to record pulse frequency and maximum pressure. Head loss was the difference between the inlet pressure of branch tee and the maximum outlet pressure of lateral pipe tee. The results showed that the total flow rate of No. I irrigation district was the smallest and the dripper flow rate was less than the rated value (2.7 L/h) because the No. I irrigation district with jet-pulse tees installed in both branch and lateral pipes had intermittent pulsed flow. The pressure and flow rate at the outlet of branch tee followed power function relationships with the fitting degree higher than 0.96 and the root mean square error smaller than 28 L/h. The irrigation uniformity coefficient of irrigation system in No. I irrigation districts ranged from 95.88% to 98.56%, which was higher than the other 3 irrigation districts by 1.02%-4.43% respectively. The flow deviation rate ranged from 8.35% to 15.14% in No. I irrigation districts, which was lower than the others by 0.46%-5.72%. It proves that the irrigation uniformity of No. I irrigation districts is the best. In No. I, II and III irrigation districts, the pulse frequency of branch and lateral pipe jets increased with the increase of the inlet head. Head loss from branch tee inlet to lateral pipe tee outlet in No. I irrigation district was 0.9-1.6 m under different branch pipe tee inlet heads, which was not significantly different from the other systems. The results of this study will contribute to the selection of the optimal combination mode of branch pipe tee and lateral pipe tee in irrigation district, and provide valuable information for the research, development and application of jet technology in pulsed drip irrigation system. In the future research, it is necessary to test the loss along the lateral pipe, observe the distribution of pressure, flow rate and pulse performance in the lateral pipe, and further evaluate the uniformity and anti-clogging ability of irrigation.

       

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