经济管径 meaning in English

economic pipe size
economical pipe size

Economic pipe size
经济管径
Based on the analyses of the investment of nozzle tube net and relationship between the annual operation cost and tube diameter function of a fixed spray irrigation system , a mathematic model to calculate the economical tube diameter of a spray irrigation system is developed by using the minimum expense norm and nonlinear planning theory in engineering economic analysis , and a direct calculation formula for the economical tube diameter in unrestrained conditions is presented
摘要在分析了固定式喷灌系统的管网投资、年运行费用与管径函数关系的基础上，利用工程经济分析中费用最小化准则和非线性规划理论，建立了求解喷灌系统管网经济管径的数学模型，并给出了无约束条件直接求解经济管径的计算式。
Aiming at the present low efficiency of well irrigation works and through pumping tests and theoretical analysis , the paper derives a method for calculating the optimum water yield , the best lifting distance and economic pipe diameter of low pressure pipe delivery system of irrigated area by wells , increasing the efficiency of motor - pumped wells
针对目前井灌工程效率低下的问题，通过抽水试验，经过理论分析，推导出了井灌低压管道输水灌溉系统的最优出水量、最佳扬程和经济管径计算方法，从而可提高机井灌溉效率。