滴灌带在低压模式下水力性能变异特征研究

Hydraulic Performance Variation Characteristics of Drip Irrigation Belt Under Low Pressure Mode

采用国内4种常规内镶贴片式滴灌带,分别在低压(10～60 k Pa)和常压(100～160 k Pa)两种供水模式下进行了滴头水力性能的对比试验研究,结果表明:常规滴灌带在低压与常压模式下的水力性能存在一定的差别,不同压力模式对常规滴灌带的流态指数x、流量偏差系数Cv均具有一定影响。在低压模式下,A、B、C型滴灌带较常压模式下x分别增大9.03%、0.41%、17.70%,D型滴灌带较常压模式下x减小13.48%,D减小幅度最大,适合在低压模式下运行; A至D型滴灌带较常压模式下Cv分别增大23.34%、10.63%、24.89%、0.82%,低压模式下滴头流量均匀性较常压模式下稍差,但也满足滴灌带质量为优等的要求。采用1stOpt对低压模式下4种滴灌带压力～流量关系式进行模拟,R2均大于0.9,模拟效果较好。

In this study,four kinds of conventional inner flat emitter drip irrigation belts were used. The comparison of the hydraulic performance of drippers under low pressure（ 10 to 60 k Pa） and normal pressure（ 100 to 160 k Pa） water supply modes was performed. The results show that： there are certain differences in the hydraulic performance of conventional drip irrigation belts under low pressure and normal pressure modes; different pressure modes have certain influence on the flow regime exponent x and flow deviation coefficient Cvof conventional drip irrigation belts; under the low pressure mode,the flow regime exponent of the A,B,and C type drip irrigation belt is increased by 9.03%,0.41%,and 17.70%,respectively,than that under the normal pressure mode; the flow regime exponent of the D type drip irrigation belt is decreased by 13.48% than that under the normal pressure mode; the decrease amplitude of D type is the maximum,so D type is suitable for operation under low pressure mode; the Cvvalue of A to D type drip irrigation belts is increased by 23.34%,10.63%,24.89%,and 0.82%,respectively,than that under normal pressure mode. This indicates that the dripper flow uniformity under low pressure mode is slightly lower than that under normal pressure mode,but still can meet the requirements of excellent drip tape quality. The results of fitting the pressure-flow relationship equations of four drip irrigation belts under low pressure mode show that the R2 value is 0.917 1,and the fitting effect was good.