Study On The Effect Of Clogging Performance Of Drip-tape With Labyrinth Channel

As the last-level equipment of the entire drip irrigation system,the hydraulic performance and physical clogging property of drip irrigation tape directly affecting the operating efficiency of the entire system.In this paper,the flow rate of 1.8L/h(H1 type)and 2.6L/h(H2 type)And 3.2L/h(H3 type)drip-tape with labyrinth channel was studied,the irrigation uniformity(clear water)and average relative flow(muddy water)of the irrigation tape was considered to be the evaluation indicators,a uniform orthogonal indoor experimental plan was designed and carried out under clear water and muddy water conditions.In order to explore the influence of laying slope(-1～1%),inlet pressure(40-120 k Pa)and laying length(10～30m)on irrigation uniformity under clear water conditions,and fertilizer concentration under turbid water conditions(0.6～3.0g/L),the influence of sand content(1～3g/L)and inlet pressure(40～100k Pa)on the average relative flow.The Statistical Product and Service Solutions and Projection Pursuit Regression was used to process the experimental data,and explore the influence of different factors on the hydraulic performance and physical clogging property of drip-tape.The results could provide a reference for the prediction of the irrigation uniformity and average relative flow of the drip-tape.Also,it could provide a reference for the construction of the drip irrigation system design and operation theory system.The main work and research results of this paper are as follow:(1)Under clear water conditions,the factors that affecting the irrigation uniformity of H1,H2 and H3drip-tapes were obtained using the range analysis,and their influence follow the descending order of:pressure> laying length> laying slope.After analysis of the variance,it was clear that the pressure has the greatest impact on the irrigation uniformity of all three drip-tape,and all reach a extremely significant level,the laying lengths of all drip-tapes reach a significant level,and the laying slopes are not significant.(2)Based on SPSS and PPR,a model consist of laying slope,working pressure,laying length and irrigation uniformity under clear water conditions was constructed.Among which,the linear model constructed using SPSS has a low degree of fitting and the model is not significant.The root mean square errors of the standardization of the nonlinear model constructed using SPSS were 1.72%(H1),0.78%(H2),0.90%(H3),respectively.And the standardized root mean square errors of the model constructed using PPR were0.09%(H1),0.14%(H2),0.37%(H3),respectively,all reached the excellent standard,and the PPR model has the best performance.(3)Under muddy water condition,the factors affecting the average relative flow of H1,H2,and H3drip-tape was analyzed using range and variance analysis,and they follow the descending order as: sand content> fertilizer concentration> working pressure.The influence of sand content on average relative flow of all three types of drip-tape reached the extremely significant level.the influence of fertilizer concentration on the average relative flow rate of the H1 drip irrigation tape reached a extremely significant level,its influence on the H2 and H3 drip-tapes reach significant level.Under these conditions,the pressure has no significant impact on all three irrigation drip-tape.(4)Based on PPR,a model that consist of fertilizer concentration,sand content,working pressure and average relative flow of drip irrigation tape under muddy water conditions was constructed.The standardized root mean square errors of H1,H2,and H3 drip-tapes were 0.66% and 0.74%,0.34%,respectively,and both reach an excellent standard.Through PPR optimization simulation calculation,the optimal working conditions of the three types of drip-tape were obtained,which are fertilizer concentration of 0.6g/L,sand content of 1g/L and working pressure of 40 k Pa.Under these conditions,the maximum average relative flow of H1,H2,and H3 are 0.7917,0.7635,0.6996,respectively.