低压条件下滴灌带灌水均匀系数试验研究

对常压滴灌系统中使用较多的6种国产单翼迷宫和内镶片式滴灌带,在低压条件下进行了滴灌带铺设长度、压力水头、地形坡度3个因素对滴灌带灌水均匀系数影响规律的试验研究,试验结果表明,0坡低压条件下,在试验的滴灌带铺设长度范围内(60～120 m),滴灌带长度较短时,影响滴灌带均匀系数的主要因素为制造偏差,随着滴灌带长度的增加,滴灌带流量大小成为影响滴灌带灌水均匀系数的主要因素,而制造偏差变为次要因素;随着滴灌带进口压力的增大,各规格滴灌带均匀系数也有所增加,当滴灌带铺设长度较大时,滴灌带的规格类型对滴灌带的灌水均匀系数存在显著影响;试验结果还表明,当滴灌带铺设坡度从逆坡-1%到顺坡1%变化时,灌水均匀系数呈逐渐增加的趋势,低压条件下逆坡对滴灌带灌水均匀系数影响尤为显著。

Uniformity Coefficient of Drip Irrigation Tapes under Low Operating Pressure

Uniformity coefficient has been one of the most frequently used criteria for micro-irrigation design and evaluation.A series of experiments about the effect of tapes' length,entrance pressure and slope gradient working on the emission uniformity were carried out in laboratory under low operating pressure.The experiment results show that uniformity coefficient declined with the increase of the drip tape length,when the drip tapes length changed form 60 m to 120 m in zero slope.When drip irrigation tapes are not very long,the main factor effecting uniformity coefficient is manufacturer's variation,as drip irrigation tapes extending,the main factor goes to the flow of emitters while manufacturer's variation becomes minor factor.Uniformity coefficient increased as the downhill slope increased with the increase of the slope in experimental range,especially the effect of uniformity coefficient was significant on the uphill slope.