自來水測漏小區管網劃分程序及優選模式

Abstract

自來水管網管線老舊破損會造成水在運送途中漏損，浪費珍貴的水資源，因而有必要執行「小區測漏」找出漏水管線，然目前測漏小區主要是依經驗劃分，多未系統化考量管網連通性及管線漏水潛勢因子，造成所劃分小區的測漏效益可能不佳。本研究因而以類似制水閥分區的獨立管網單位(Independent Network Unit, INU)當作小區劃分的基本單位，以簡化原始複雜的管網系統，並根據管線損壞機率、供水面積管線長度、用戶數量等因子，研擬可合理反應管網漏水潛勢的三個因子，且據以建立一個啟發式的優先測漏小區劃分程序，該方法可迅速取得結果，唯可能不是優選解，因而進一步提出優選模式劃分優先測漏小區，並應用基因演算法求解，以期求得管網中具有最大漏水潛勢因子的優先測漏小區，利於水公司執行小區測漏，提升管網檢漏效率。 本研究以台中巿第四區的管網案例測試所發展程序及模式的適用性與可行性，以劃分三區的結果發現所發展的程序確可劃分出漏水潛勢因子所定義的高漏水潛勢小區，其中以依單位管長漏水潛勢因子所得結果最佳，以單位面積漏水潛勢因子所得結果最差。而模式所劃分出的優先測漏小區，證明可改善啟發式程序的缺點，劃分出更高漏水潛勢的小區，且聚集了較多個INUs，供進一步縮小可能漏水之區域，讓測漏的效率與效益更高。

In an aged water distribution network (WDN), a significant amount of water is frequently lost due to pipeline leakage. In order to prevent the leakage, delineating a WDN into numerous District Metering Areas (DMAs) is an effective approach for implementing leakage detection tasks. In Taiwan, DMAs were usually divided based on the empirical experiences of related engineers or planners without actually evaluating the leakage potential and connectivity of the DMAs. In this study, the Independent Network Unit (INU) is proposed to simplify a complex WDN and to serve as the smallest unit to form a DMA. The leakage potential of a DMA is evaluated based on a pipe failure rate and three major factors of leakage potentials per unit area, per unit pipe length, and per consumer, respectively. A heuristic procedure is proposed to delineate DMAs. Although the procedure can divide DMAs efficiently, the solution obtained may not be the optimum. An optimization model is thus developed and a Genetic Algorithm (GA) is applied to solve the model. The procedure and the model proposed in this study are intended to provide systematic approaches to delineate DMAs which have high leakage potential. The Taichung City WDN of the Taiwan Water Corporation is the case study area for demonstrating the applicability of the proposed procedure and model. The procedure was applied to find three DMAs with high leakage potential based on the three aforementioned factors. The results for the leakage potentials per pipe length and per consumer are obviously superior to those for the leakage potential per unit area. The results obtained by the model can delineate DMAs with obviously larger leakage potential and more INUs than those obtained by the heuristic procedure, and subsequently the leakage detection tasks can be effectively implemented.