Effect of emitters manufacturing variation of micro-irrigation on uniformity and lateral cost
Zhu Delan1, Wu Pute 1,2, Wang Jian1
(1.China Arid area Water saving Agricultural Institute, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China; 2.College of Resources and Environment,Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, China)
Abstract:In order to find the relationship among the emitter manufacturing variation coefficient, the lateralcost and the lateral diameter, and to decrease the cost of drip irrigation engineering the allowable values of the emitters manufacturing variation coefficient are analyzed for different emission uniformity coefficients(EEU). Then, the relationship among the esmitters manufacturing variation coefficient, lateral diameter,and the EEUis investigated.The function of the lateral cost is also parameterized.An application illustration shows that the pipe cost increases by 8.7% and 37.1% when the emitters manufacturing variationcoefficients increase from 0.05 to 0.07 and 0.11, respectively, for the lateral length of 100 m and EEUof 0.80. When the EEUincreases from 0.80 to 0.85, 0.90 and 0.95, the lateral diameter increasesby 20%,23.5% and 56.5% and lateral cost increases by 20%,53.8% and 207.7%, respectively, for the emitters manufacturing variation coefficient of 0.03. For the emitters manufacturing variation coefficient of 0.05, when EEUincreases from 0.80 to 0.85, 0.90, the lateral diameter increases by 19.3% and 32.8%, and lateral cost increased by 17.1% and 71.4%, respectively. In addition, when the EEUis 0.95, the hydraulic calculation cannot be performed, because the allowable hydraulic variation is negative. It is concluded that the lateral diameter and cost increase significantly with increasingthe emitters manufacturing variation coefficient and the given uniformity coefficient. Furthermore, when the emitters manufacturing variation coefficient or the emission uniformity coefficient is larger than a preset value, the hydraulic design can not be carried out.
[1]张国祥,吴普特.滴灌系统滴头设计水头的取值依据[J].农业工程学报,2005,21(9):20-22.Zhang Guoxiang,Wu Pute. Determination of the design working head of emitter[J]. Transactions of the CSAE ,2005,21(9): 20-22.(in Chinese)[2]王新坤. 基于二分法的微灌毛管水力设计[J]. 排灌机械,2007,25(6):27-30.Wang Xinkun. Hydraulic design of micro irrigation lateralsbased on bisection method[J]. Drainage and Irrigation Machinery ,2007,25(6):27-30.(in Chinese)[3]中华人民共和国水利部. GB/T 50485—2009 微灌工程技术规范[S]. 北京:中国计划出版社,2009.[4]Keller J,Bliesner R D. Sprinkler and Trickle Irrigation [M]. New Jersey:The Blackburn,1990: 498-508.[5]Wu I P. An assessment of hydraulic design of microirrigation systems [J]. Agricultural Water Management ,1997,32(3):275-284.[6]张国祥. 考虑三偏差因素的滴灌系统流量总偏差率[J].农业工程学报,2006,22(11):27-29.Zhang Guoxiang. Calculating the total flow deviation rate of drip irrigation system based on three deviationrates[J]. Transactions of the CSAE ,2006,22(11): 27-29.(in Chinese)[7]张 林,范兴科,吴普特,等. 均匀坡度下考虑三偏差的滴灌系统流量偏差率的计算[J]. 农业工程学报,2009,25(4):7-14.Zhang Lin,Fan Xingke,Wu Pute,et al. Calculation of flow deviation rate of drip irrigation system taking three deviation rates into account on uniform slopes[J]. Transactions of the CSAE ,2009,25(4):7-14.(in Chinese)[8]朱德兰,吴普特,王艳群,等. 滴头设计工作压力计算方法研究[J]. 排灌机械,2005,23(5):31-34.Zhu Delan,Wu Pute,Wang Yanqun,et al. Study on the calculation method of operation pressure of emitters[J]. Drainage and Irrigation Machinery ,2005,23(5):31-34.(in Chinese)[9]Barragan J,Bralt V,Wu I P. Assessment of emission uniformity for microirrigation design [J]. Biosystems Engineering ,2006,93(1): 89-97.[10]Wu Pute,Zhu Delan,Jin J,et al,Design of drip irrigation lateral for optimum capital and operating cost[J]. Water Science and Technology ,2010,10(6):943-953.