管網(wǎng)管理以及如何降低管網(wǎng)漏失率是供水公司的一項(xiàng)主要的挑戰(zhàn)任務(wù)。
供水管網(wǎng)管道長(zhǎng)達(dá)幾千公里,但每隔幾米就會(huì)有一個(gè)短管接口。這些管道通常比較陳舊,又受到了路面交通及其他負(fù)載壓力的影響;且大部分是鑄鐵管或鋼管,銹蝕的影響很大;舊管爆漏導(dǎo)致客戶服務(wù)中斷是常有的是,因此管網(wǎng)漏失就在所難免。所以,供水公司必須有清晰的管網(wǎng)管理政策使漏失率得到有效的控制。
管網(wǎng)內(nèi)水量可分為兩類:被客戶消費(fèi)的水量和漏失掉的水量(又稱水損)。水損又可細(xì)分為真正水損(物理漏失)與商業(yè)水損(或指因客戶服務(wù)及計(jì)量所產(chǎn)生的損失)。分述如下:
^物理漏失是已經(jīng)出廠但終端用戶沒(méi)有消費(fèi)的水量。
^商業(yè)水損是已經(jīng)出廠并被終端用戶消費(fèi)但沒(méi)法收回水費(fèi)的水量。
管網(wǎng)效率是供水公司的重要指標(biāo),它可以從下述措施中獲得改善:
^降低物理漏失(如漏水、蓄水池溢流等)可以避免或延緩為提高水量或管網(wǎng)過(guò)水能力而不得不做的投資。
^商業(yè)水損的降低可通過(guò)改進(jìn)客戶服務(wù)管理來(lái)實(shí)現(xiàn)(如改善水表誤差、打擊偷水行為等),以達(dá)到增加水費(fèi)回收的目的。
消費(fèi)及損失水量組成
下表是消費(fèi)及損失水量(灰色)組成明細(xì)表:
Volumes Distributed 輸送水量 |
Authorised Consumption 被消耗水量 |
Authorised Billed Consumption 認(rèn)可收費(fèi)水量 |
Billed Measured Consumption 計(jì)量收費(fèi)水量 |
Exported Water 輸出水量 |
Revenue Water 銷售水量 |
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Residential,commercial and Industrial Customers 居民、商業(yè)及工業(yè)用戶 |
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Unmeasured Billed Consumption 未計(jì)量收費(fèi)水量 |
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Authorised Unbilled Consumption 認(rèn)可的非收費(fèi)水量 |
Measured Unbilled Consumption計(jì)量非收費(fèi)水量 |
NRW Non-Revenue Water 產(chǎn)銷差 |
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Unmeasured Unbilled Consumption未計(jì)量非收費(fèi)水量 |
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Operational Usage營(yíng)運(yùn)水量 |
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Losses 水損 |
Apparent Losses (or Commercial and Metering Losses)表面水損(商業(yè)水損或計(jì)量水損) |
Illegal Usage 非法用量 |
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Metering Losses計(jì)量水損 |
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Billing Losses水費(fèi)回收水損 |
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Real Losses (Physical Losses) 真正漏損(物理漏損) |
Leaks on Primary Networks 主管網(wǎng)漏失 |
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Leaks and Overflows on Operators Storage Facilities 水廠蓄水設(shè)施漏失或溢流 |
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Leaks on Network 管網(wǎng)漏失 |
Visible leaks 可見(jiàn)漏失 |
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Invisible Leaks 不可見(jiàn)漏失 |
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除上表詳列消耗水量及水損分類外,我們還可以用下圖來(lái)加以描述。
* The % figures are only examples and will vary for each water company.上述百份比數(shù)字僅供示例,每個(gè)供水公司的實(shí)際數(shù)字會(huì)各不相同。指標(biāo)
供水公司通常使用的指標(biāo)很多,具體如下:
供水量水損百分比
供水公司最常用的水損指標(biāo)是水損量占供水量或計(jì)算地區(qū)供水量的百分比。
這一指標(biāo)簡(jiǎn)單明瞭,便于計(jì)算,但有兩個(gè)缺點(diǎn):
這是一項(xiàng)國(guó)際通用指標(biāo),但無(wú)法體現(xiàn)水損分類。
不能對(duì)不同類型管網(wǎng)的運(yùn)行狀況進(jìn)行合理比較。
根據(jù)各種參考值或長(zhǎng)度因素計(jì)量的單位水損
以某個(gè)參考值除以年水損量,可獲得可比較的比率,從而對(duì)不同規(guī)模、不同特點(diǎn)的管網(wǎng)進(jìn)行比較。
常用比率如下:
單位管網(wǎng)長(zhǎng)度的水損
單位進(jìn)戶管的水損
單位物業(yè)的水損(如英國(guó))
單位管網(wǎng)總長(zhǎng)(包括管網(wǎng)和進(jìn)戶管)的水損
推薦方法
當(dāng)考慮一個(gè)已知管網(wǎng)時(shí),一定要盡可能詳細(xì)地了解,包括水損數(shù)據(jù)和導(dǎo)致水損的不同因素,以便制定可行的計(jì)劃來(lái)降低水損。
一旦建立“水損餅圖”,各項(xiàng)指標(biāo)的計(jì)算就很簡(jiǎn)單了。
Network Efficiency = (Billed volumes + Authorised unbilled consumption + Exported volumes) / (Total Volumes supplied to the system).
管網(wǎng)效率=(收費(fèi)水量+認(rèn)可非收費(fèi)水量+傳輸水量)/總供水量
管網(wǎng)效率可以按12個(gè)月滾動(dòng)平均做基礎(chǔ)。
或者
LLI (Linear Loss Index in m3/year/km) = Loss (in m3/year) / Length of network (excluding the length of the service connections in km)
LLI(線性水損指數(shù)m3/年/公里)=水損(m3/年)/管網(wǎng)長(zhǎng)度(不包括進(jìn)戶管長(zhǎng)度)
對(duì)一個(gè)管網(wǎng)經(jīng)理來(lái)說(shuō),最基本的是要降低產(chǎn)銷差水量(用立方米表示)。用立方米表示的水損計(jì)算比較單一、簡(jiǎn)單,因此通常被用作其他指數(shù)的計(jì)算基礎(chǔ)。
實(shí)施計(jì)劃應(yīng)包括的內(nèi)容
前三部分的目標(biāo)主要是讓大家知道影響水損值的主要數(shù)據(jù)越精確越好。
1.供水量總計(jì)量的控制與優(yōu)化方案
2.抄表及發(fā)單收費(fèi)的優(yōu)化方案
3.特許的非收費(fèi)水量的控制與降低方案
接下來(lái)的三個(gè)部分的主要目標(biāo)是降低水損每個(gè)主要元素。
4. 物理漏損的檢測(cè)與降低方案:檢測(cè)維修可見(jiàn)與不可見(jiàn)漏水點(diǎn),更新管網(wǎng),控制蓄水池溢流。
5.減少水表(負(fù))誤差數(shù)量方案,或稱水表圓管理。(即減少慢表,提高收費(fèi)水表)
6.商業(yè)水損的檢測(cè)與降低方案(客戶服務(wù)管理)
最后,不論使用什么方案降低水損,只有改進(jìn)公司的運(yùn)行狀況(架構(gòu)、流程、人力資源等)才能產(chǎn)生永久的效果。
下表列出了部分通常要求的典型診斷和行動(dòng)計(jì)劃。
TYPE OF LOSS 水損類別 |
D:DIAGNOSTIC(*)診斷 |
P: ACTION PLAN(**) |
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A |
EFFICIENCY CALCULATION 效率計(jì)算 |
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Volumes produced and imported 生產(chǎn)及輸入水量與輸出水量 |
DA1 |
Existence of meters(or not) |
PA1 |
Installation or replacement of flowmeters |
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DA2 |
Maintenance procedures |
PA2 |
Improvement of maintenance procedures |
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DA3 |
Test on meters |
PA3 |
Tests and calibration of flow-meters(continued) 調(diào)試校正流量計(jì) |
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Volumes consumed and billed 認(rèn)可消費(fèi)水量和發(fā)單水量 |
DA4 |
Diagnostic of customers procedures |
PA4 |
Improvement of customers procedures |
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DA5 |
Diagnostic of information system |
PA5 |
Improvement of replacement of |
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Volumes legally consumed |
DA6 |
Inventory |
PA6 |
Meter installation campaign (when possible) |
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DA7 |
Measurement or evaluation procedures |
PA7 |
Reduction of water service consumption |
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DA8 |
Test of evaluation |
PA8 |
Reduction of exonerated consumption |
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General 概述 |
DA9 |
History |
PA9 |
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B |
PHYSICAL |
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Visible leaks |
DB1 |
Statistic |
PB1 |
Improvement or creation of call centers |
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DB2 |
Audit on procedures |
PB2 |
Reduction of repair duration |
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DB3 |
Visual pilot survey |
PB3 |
Formation of team for visible leaks detection |
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DB4 |
PB4 |
Location of leaks on GIS |
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Invisible leaks |
DB5 |
Statistic |
PB5 |
Purchase of equipment |
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DB6 |
Audit on method used |
PB6 |
Formation of team for invisible leak detection |
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DB7 |
Pilot detection campaign |
PB7 |
Outsourcing of leak detection |
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DB8 |
PB8 |
Invisible leaks detection and repair campaign |
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DB9 |
PB9 |
Installation of a monitoring |
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Leaks on mains |
DB10 |
Statistic |
PB10 |
Leak detection campaign with appropriate equipment |
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DB11 |
Audit on procedures |
PB11 |
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Tank overflow |
DB12 |
Audit on protection equipment |
PB12 |
Installation or rehabilitation of tanks |
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DB13 |
Audit on tele information |
PB13 |
Remote system control |
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Tank infiltration |
DB14 |
Audit of drains |
PB14 |
Repair of leaks and/or waterproof joints replacement 修漏或更換止水縫 |
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General |
DB15 |
Audit on sectorisation (districts) |
PB15 |
Waste districts metering system 廢水排放系統(tǒng)安表 |
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DB16 |
Audit on pressure of service |
PB16 |
Pressure Control System |
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C |
METERING LOSSES |
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Undermetering due to |
DC1 |
Analyse of the database |
PC1 |
Program of Meter Replacement |
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Undermetering due to |
DC2 |
Sample study on large customers |
PC2 |
Program of Replacement or Resizing |
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Undermetering due to meter aging |
DC3 |
Sample study on small meters |
PC3 |
Massive Replacement Program of small meters |
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DC4 |
Profile of consumption |
PC4 |
Studies of meters-datalogging |
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DC5 |
PC5 |
Test of new meters and technical watch |
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DC6 |
PC6 |
Purchase of a meter test bench |
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D |
COMMERCIAL LOSSES |
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Illegal connections |
DD1 |
Inventory on pilot area |
PD1 |
Complete census |
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Frauds on registered connectins |
DD2 |
Analyse of the existing database |
PD2 |
Targeted census |
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DD3 |
Sample surveys |
PD3 |
Targeted field surveys |
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Frauds on equipment |
DD4 |
Inventory |
PD4 |
Communication campaign |
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DD5 |
Sample surveys |
PD5 |
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Low income areas |
DD6 |
Pilot surveys |
PD6 |
Multi-purpose actions depending |
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Billing losses |
DD7 |
Survey on IS and procedures |
PD7 |
Improvement of Customer Services of procedures |
(*)通常來(lái)講,任務(wù)D的黑體部分是最后診斷的內(nèi)容。
(**)任務(wù)P的黑體部分是最常采用的措施。任務(wù)D與任務(wù)P同行之間沒(méi)有關(guān)聯(lián)。
照片
引至大面積停水的某城市中心大型水管爆管
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聽(tīng)漏
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使用Permalog系統(tǒng)測(cè)漏
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管道接頭漏水
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