不同泥沙质量浓度及工作压力对微孔地下渗灌管渗水性能的影响

【目的】明晰灌溉水泥沙质量浓度和压力对微孔地下渗灌管渗水性能的影响,为微孔地下渗灌管的田间应用提供理依据。【方法】在0~100 kPa压力范围内,用自来水和浑水对微孔地下渗灌管进行通水试验,分析压力和泥沙质量浓度对微孔地下渗灌管渗水性能的影响。【结果】①灌溉水泥沙质量浓度增加,渗水速率随通水时间延长持续降低。②不同泥沙质量浓度条件下,管道流态指数均大于1,相关系数R^2大于0.98,渗水速率对压力变化敏感。随着泥沙质量浓度的增加,管道渗水速率对压力的敏感程度增加。③进水口压力越小对灌溉水源的要求越高,高压力条件下可适当减缓灌溉水中泥沙给管道渗水性能带来的影响。【结论】灌溉水泥沙量是影响微孔地下渗灌管渗水性能的主要因素,当泥沙质量浓度小于1.0 g/L时,增大灌溉系统压力可有效保障微孔地下渗灌管渗水性能。

Effects of Sediment Concentration and Operating Water Pressure on Exfiltration of Subsurface Microporous Infiltration Irrigation Pipe

【Objective】Understanding the influence of water purity and water pressure in micro-irrigation system is important to ensure its operation.The objective of this paper is to present results of an experimental study on how operating water pressure and sediment concentration of irrigation water combined to affect exfiltration of subsurface microporous infiltration irrigation pipe.【Method】The experiment used tap water and muddy water,with the operating pressure varying from 0 to100 kPa.During the experiment,the change in exfiltrating rate in response to water pressure and sediment concentration was measured and analyzed.【Result】①With the increase in sediment concentration,the water exfiltration rate monotonically decreased as time elapsed.②The flow regime index of the irrigation pipe was greater than 1;correlation coefficient was greater than 0.98;the exfiltration was sensitive to the pressure in that with the increase in sediment concentration,the exfiltration rate of the pipeline became increasingly sensitive to the pressure.③The lower the pressure was,the higher it required the purity of the irrigation water to be.Increasing the pressure can compensate the adverse effect of the sediment concentration to some extent.【Conclusion】When irrigation water contains silt,increasing water pressure in the irrigation system could alleviate sediment blockage and ensure safe operation of the subsurface microporous infiltration irrigation pipe.