基于混合和谐搜索算法的自压滴灌田间管网多目标优化设计

Multi-objective Optimization Design of Self-pressure Drip Irrigation Field Pipe Network Based on Mixed Harmony Search Algorithm

为了综合考虑管网投资和水压分布,合理进行管网布置和管径选择,以满足管网的经济性和可靠性,使自压滴灌管网系统达到投资最低和灌水均匀度最高的目的。以管网投资最低(管网经济性)和节点富余水头均值最小(管网可靠性)为目标,建立了自压滴灌“梳子”形和“丰字”形田间管网系统的多目标优化数学模型,提出了混合和谐搜索算法求解多目标优化模型的方法和步骤。以新疆某自压滴灌工程为例,采用该方法对其田间管网系统进行优化,优化方案的管网总投资为47.63万元,与原设计方案相比降低了9.86%;管网节点富余水头均值为8.87 m,与原设计方案相比降低了28.37%。该优化设计方法得到的优化结果,不仅节省投资明显,而且节点富余水头均值显著减小,说明管网系统的压力偏差小,灌水的均匀度显著提高。优化结果表明,混合和谐搜索算法收敛速度快,计算精度高,在自压滴灌管网的多目标优化设计中具有很好的应用价值。

Considering the investment and water pressure distribution of the pipe network,it is essential to design the pipe network layout and select pipe diameters in a manner that ensures both economic efficiency and system reliability for self-pressure drip irrigation systems,so that the self-pressure drip irrigation pipe network system can achieve the purpose of the lowest investment and the highest irrigation uniformity.With the goal of minimizing investment in the pipe network(pipe network economy)and minimizing the average value of the node surplus head(pipe network reliability),the multi-objective optimization mathematical models of the self-pressure drip irrigation"comb"type and"Fengzi"type field pipe network system are established.Furthermore,the methods and steps of the mixed harmony search algorithm to solve the multi-objective optimization model are proposed.Taking a self-pressure drip irrigation project in Xinjiang as an example,the field pipe network system was optimized by this method,and the total investment of the pipe network of the optimization scheme was 476,300 yuan,which was 9.86%lower than the original design scheme.The average head value of the surplus water head of the pipe network node was 8.12 m,which was 33.87%lower than the original design scheme.The optimization results obtained by this optimization design method not only yield significant cost savings,but also significantly reduce the average value of the surplus water head at the node,indicating that the pressure deviation of the pipe network system is small and the uniformity of irrigation is significantly improved.At the same time,the hybrid harmony search algorithm has stable convergence,fast calculation speed and high calculation accuracy,which has good application value in the multiobjective optimization design of self-pressure drip irrigation pipe network.