在机压微灌工程设计中,经济管径的确定问题,文献[1]已进行了阐述,为微灌经济管径的确定奠定了理论基础。笔者认为在应用过程中,还应考虑货币的时间价值。为此本文提出了一种确定支管以上经济管径的查图、表方法,以供设计者参考。 1.经济管径的确定原则设计中,同一种管道布置形式,管径的选择有多种方案。只要水量均匀,满足作物 In the design of mechanical pressure micro-irrigation engineering, the determination of the economic pipe diameter, literature [1] has been elaborated, which has laid a theoretical foundation for the determination of micro-irrigation economic pipe diameter. I think in the application process, we should also consider the time value of money. For this reason, this paper presents a look-up chart and table method to determine the economic pipe diameter above the branch pipe for the reference of designers. 1. The principle of determining the economic diameter Design, the same type of pipe layout, diameter selection of a variety of programs. As long as the amount of water to meet the crop