基于投资成本和可靠性的机压滴灌管网系统多目标优化方法

Multi-objective Optimization Method of Machine-pressed Drip Irrigation Pipe Network System Based on Investment Cost and Reliability

摘要:

滴灌管网系统在降低工程投资和运行成本的前提下提高可靠性，是优化设计亟需解决的关键问题。针对机压滴灌特点，以管网年投资费用最低、节点富余水头均值最小和节点富余水头方差最小为目标，建立了机压滴灌管网系统多目标优化设计数学模型，提出了改进和声搜索算法求解多目标优化模型方法和步骤。在构建优化模型中，将管网系统按照级、条、段为单元划分，使建立的优化模型具有通用性。以新疆某机压滴灌工程为例，采用该方法对其管网进行优化，与原设计方案相比，优化方案滴灌系统年投资成本降低4.97%，管网节点富余水头均值降低16.84%，管网节点富余水头方差降低12.47%。优化结果表明，该方法不仅能有效降低管网系统投资成本，而且节点富余水头均值和节点富余水头方差显著减小，降低了管网系统压力偏差和故障发生频率，从而提高了管网系统可靠性。

Abstract:

Drip irrigation is one of the irrigation methods with the most significant water-saving effects in modern agricultural irrigation. How to improve the reliability of drip irrigation pipe network systems while reducing project investment and operation costs is a key issue that needs to be addressed urgently in optimal design. Aiming at the characteristics of machine-pressure drip irrigation, a multi-objective optimal design mathematical model for machine-pressure drip irrigation pipe network systems was established with the objectives of minimizing the annual investment cost of the pipe network, the mean value of node surplus head, and the variance of node surplus head. An improved harmony search algorithm was proposed to solve the multi-objective optimization model, along with its methods and steps. In constructing the optimization model, the pipe network system was divided into units of levels, strips, and sections, making the established optimization model universal. Taking a machine-pressure drip irrigation project in Xinjiang as an example, this method was used to optimize its pipe network. Compared with the original design scheme, the optimized scheme reduced the annual investment cost of the drip irrigation system by 4.97%, the mean value of node surplus head by 16.84%, and the variance of node surplus head by 12.47%. The optimization results showed that this method can not only effectively reduce the investment cost of the pipe network system, but also significantly reduce the mean value and variance of node surplus head, thereby reducing the pressure deviation and failure frequency of the pipe network system and improving its reliability.