膜下滴灌系統(tǒng)的組成與規(guī)劃設計（定稿）

膜下滴灌系統(tǒng)的組成與規(guī)劃設計

TheComponentandDesignofDripIrrigationSystemunderMulchFilm

國家節(jié)水灌溉工程技術研究中心（新疆）NationalCenterofEfficientIrrigationEngineeringandTechnologyResearch-XinJiang何林望HeLinwang1、膜下滴灌系統(tǒng)的組成

ComponentofDripIrrigationSystemunderMulchFilm

水源工程Watersourceproject

首部樞紐Headofpivot

輸配水管網(wǎng)Pipenetworksforwatertransportation

滴頭及控制測量和保護裝置

Emitters,pressureregulator,measuringmeterandprotectiondevices1.水源WaterSource2．水泵Pump3.供水管WaterSupplyPipe4.蓄水池Pond5.逆止閥BackflowPreventionDevice6.施肥開關Fertilizervalve7.灌水總開關IrrigationHeadValve

13.滴頭Emitter14.毛管(滴灌帶)Lateral(Dripline)15.滴灌支管Manifold16.尾部開關(電磁閥)ZoneValve(Electricalvalve)17.沖洗閥FlushValve18肥料罐FertilizerTank19.肥量調(diào)節(jié)閥FertilizerRegulator

20.施肥器FertilizerInjector

21.干管MainLine2、膜下滴灌系統(tǒng)設備

EquipmentofDripIrrigationSystemunderMulchFilm

2.1滴灌管（帶）

Dripline(tape)柱狀滴頭Columnardriptape

微噴帶

Micro

spraytape

壓力補償式滴頭Pressurecompensatingdriptape微噴Micro-sprinkle2.2輸配水管道

Pipesforwatertransportation

PVC干管PVCMainpipePE支管、輔管PESubmainLine

pipeandFeederLinepipe

2.3首部控制樞紐HeadControl

水泵Pump過濾設備Filtrationdevice12347568離心式過濾器CentrifugalFilterWateroutletwaterinlet3.罐體tanksandinletsandoutlet6.支架supportsand-inpotflushingoutletCentrifugalFilter網(wǎng)式過濾器ScreenFilter離心網(wǎng)式過濾器組合UnitedCentrifugalFilterandScreenFilter砂石過濾器SandFilter工作原理OperatingPrincipleInletShelfBodyFilterMediumOutlet疊片式過濾器DiscFilter施肥罐：FertilizerTank3.膜下滴灌系統(tǒng)的規(guī)劃設計

ProjectPlanningandDesignofDripIrrigationSystemunderMulchFilm

Basicprincipleofprojectplanning滴灌工程的規(guī)劃應與農(nóng)田基本建設規(guī)劃相結合Projectofdripirrigationshouldconsiderthebasicconstructionoffarmland.近期需要與遠景發(fā)展規(guī)劃相結合

Requirementinthenearfutureshouldconnectwithdevelopmentinthefuture.滴灌工程的規(guī)劃應綜合考慮工程的經(jīng)濟、社會和生態(tài)效益。

Projectofdripirrigationshouldtakeintoaccountbenefitsofeconomic,socialandecology.3.1.2規(guī)劃的內(nèi)容

Contentsofproject勘測收集基本資料Surveyandcollectbasicdata論證工程的必要性和可行性Evaluatenecessityandfeasibilityofproject確定工程的控制范圍和規(guī)模

Ascertaincontrollingareaandscopeofproject選擇適當?shù)娜∷绞紺hooseproperfetchingwatermode滴灌系統(tǒng)選型Choosedripirrigationsystem工程布置Projectdisposal做出工程概算Workoutprojectbudgetaryestimates3.1.3資料的收集

Data

collection地理位置與地形資料Geographicallocationandtopographydata土地與工程地質(zhì)資料Soilandprojectgeologydata水文與氣象資料Hydrologyandweatherdata農(nóng)作物資料Cropdata水源與動力情況Watersourceanddrivercondition社會經(jīng)濟狀況及農(nóng)業(yè)發(fā)展規(guī)劃方面的基本資料

Situationofsocialeconomyandagriculturedevelopmentproject3.2滴灌系統(tǒng)的布置

Layoutofdripirrigationsystem控制面積的確定Ascertainmentofcontrollingarea水源供水流量穩(wěn)定且無調(diào)蓄能力時可用下式確定滴灌面積Usethefollowingformulatodecideirrigationarea,aswaterissupplyingstablyandnoadjustment:式中：intheformula：

A——可灌面積，hm2；irrigationarea，hm2；Q——可供流量，m3/h；flowrate，m3/h；Ia——設計供水強度，mm/d；designedwatersupplyintensity，Ia=Ea-P0Ea——設計耗水強度，mm/d；designedwaterconsumeintensity，mm/d；P0——有效降雨量，mm/d；efficiencyofrainfall，mm/d；t——水源每日供水時數(shù)，h/d；hourofwatersupplyeveryday，h/d；η——灌溉水利用系數(shù)。coefficientofirrigationwater.

水源有調(diào)蓄能力且調(diào)蓄容積已定時，可用下式確定滴灌面積Usethefollowingformulatodecideirrigationarea,aswatersourceisadjustableandadjustingcubageisfixed：

式中：intheformula：

K——塘壩復蓄系數(shù)，K=1.0—1.4；K——efficiencyofponddamrepeatedsavingwater，；η——蓄水利用系數(shù)，η=0.6—0.7；η——coefficientofsavingwater，η=0.6—0.7；V——蓄水工程容積，m3；V——watersavingprojectcubage，m3；Ii——灌溉季節(jié)各月的毛供水強度，mm/d；Ii——grosswatersupplyintensityofeverymonthinirrigationseason，mm/d；Ti——灌溉季節(jié)各月的供水天數(shù)，d。Ti——supplywaterdaynumberofeverymonthinirrigationseason，d.3.2.2常見的幾種管網(wǎng)布置方式

Somefamiliarpipenetworkslayouts水源位于田塊的中心，控制面積較大時，常采用一字形樹枝裝管網(wǎng)布置形式“一”disposaltreeformofpipenetworks,ascontrollingareaislargeorwatersourceislocatedincenterofthefield.“一”字形布置“一”disposalT形布置“T”disposal梳齒形布置Combformdisposal

3.3系統(tǒng)設計參數(shù)的確定

Ascertainmentofsystemdesignparameter

基本參數(shù)Basicparameter1、設計保證率Insurancerateofdesign2、灌溉水的利用率不低于90%Irrigationwateruseefficiencyisnotlessthan90%3、設計系統(tǒng)的日工作小時應根據(jù)不同水源和農(nóng)業(yè)技術條件確定，一般不宜大于20hWorkhourofdesignedsystemaccordingtodifferentwatersourceandagriculturetechnicalcondition,anditisbetternottoworkmorethan20hours.4、滴頭設計工作水頭應取所選滴頭的額定工作水頭，或由滴頭壓力與流量關系曲線確定。Choosenominalworkingwaterheadasworkpressure,ordoaccordingtopressureandflowratecurveofemitter.5、設計耗水強度應采用作物耗水強度峰值，并應由當?shù)卦囼炠Y料確定。Designedconsumewaterintensity（Ea）：shouldadoptcropconsumewaterpeakvalue，localexperimentdatadecidetheEa.6、計劃土壤濕潤層深度，不同作物不同生育階段的計劃濕潤層深度不一樣，根據(jù)各地的經(jīng)驗確定。Planeddepthofwettedsoil（Z）：planeddepthofwettedsoilindifferentcropanddifferentgrowthstagearedifferent，accordingtodifferentlocalexperience.3.3.2灌溉制度

Irrigationscheme設計灌水定額：根據(jù)當?shù)卦囼炠Y料按下面公式之一計算Designirrigationquota：Accordingtolocalexperimentdatum,useoneofthereinafterformulastocalculate:m=0.1γZP(θmax-θmin)/ηOrm=0.1ZP(θmax-θmin)/η式中：intheformulas：

m——設計灌水定額mm；designirrigationquota(mm)；γ——土壤容重g/cm3；

γ——soildensityg/cm3，toselectaccordingtoFig.2.3-1；z——計劃土壤濕潤層深度m；z——thedepthofplannedwettedsoilm；P——濕潤比%；P——percentageofwettedarea%；θmax、θmin——適宜土壤含水率上、下限（占干土重的百分比），θmax可取田間持水率的90%，θmin可取田間持水率的60%，可根據(jù)表2.3-1選用；θmax、θmin——upanddownlimitofwatercontent（weightpercentageindrysoil），θmaxreferto90%offieldmoisturecapacity，θminreferto60%offieldmoisturecapacity.Choosetheparameter；θmax、θmin——適宜土壤含水率上、下限（占土壤體積百分比）,θmax可取田間持水率的90%,θmin可取田間持水率的60%，可根據(jù)表2.3-1選用；θmax、θmin——upanddownlimitofwatercontent（cubagepercentageindrysoil），θmaxreferto90%offieldmoisturecapacity，θminreferto60%offieldmoisturecapacity.Choosetheparameter.η——灌溉水利用系數(shù)。η——irrigationwaterusecoefficient.表3-1不同土壤的物理特性表

Table3-1physicalcharacteristicsofdifferentsoil土壤質(zhì)地Soilcharacteritisc容重Density（g/cm3）田間持水量Fieldmoisturecapacity

凋萎系數(shù)Wiltingcoefficient

重量含水率WCWM(%)體積含水率CCWM（%）重量含水率WCWM(%)體積含水率CCWM

%）砂土Sand1.45-1.8016-2026-32

砂壤土Sandysoil

1.36-1.5422-3032-404-65-9輕壤土Lightloam

1.40-1.5222-2830-364-96-12中壤土loam1.40-1.5522-2830-356-108-15重壤土Heavyloam

1.38-1.5422-2832-426-139-18輕粘土Lightclay

1.35-1.4428-3240-451520中粘土clay1.30-1.4525-3535-4512-1717-24重粘土Heavyclay1.32-1.4030-3540-50

設計灌水周期：可按下式計算Designirrigationintervalcalculateaccordingtothereinafterformula:T=（m/Ea）η式中：T——設計灌水周期d；Intheformula：T——designedirrigationcycled；Ea——設計耗水強度mm/d。Ea——designedwaterconsumeintensitymm/d.按上式求得的值為作物需水高峰期的灌水周期。Withforegoingformula,wecouldworkoutirrigationwatercycleasthecycleatpeakofcroprequirementwater.一次灌水延續(xù)時間Durationofirrigation

t=m?Se?Sr/（ηqd）式中：t——一次灌水延續(xù)時間h；intheformula：t——durationofoneirrigation(h)；qd——設計滴頭流量l/h。qd——designeddischargeofemitterl/h.灌水次數(shù)與灌水總量的確定irrigationtimesandgrossirrigationquality

3.3.3滴灌灌水均勻度

Irrigationuniformityofdripirrigation

滴灌均勻系數(shù)Uniformitycoefficientofdripirrigation

灌水器設計允許流量偏差率qv應不大于20%，設計灌水均勻度不應低于0.95。Designedallowableflowratedeviation(qv)islowerthan20%，designirrigationuniformityisbetterthan0.95.灌水小區(qū)允許水頭偏差Permitflowratedeviationofirrigationblock滴頭工作水頭偏差率hV與流量偏差率qV之間的關系可用下式表示：Wecouldusethereinafterformulatoshowrelationofdeviationrateofemitterworkwaterhead(hv)andpermitflowratedeviation(qv)：式中：X——滴頭流態(tài)指數(shù)。intheformula：X——emitterdischargeexponent。灌水小區(qū)允許水頭偏差按下式計算：Wecanworkoutpermitflowratedeviationofirrigationdistrictwiththereinafterformula：[ΔH]=hV×hd式中：[ΔH]——灌水小區(qū)允許水頭偏差，m；intheformula：[ΔH]——permitflowratedeviationofirrigationdistrict，m；hd——設計滴頭工作水頭，m。hd——designemitterworkwaterhead，m.3.4.滴灌系統(tǒng)設計

Designationofdripirrigationsystem毛管設計Driptapedesign1、滴灌帶的選型Driptapespecification2、水平毛管極限滴頭個數(shù)的確定Confirmlimitdrippernumbersofdriptape式中：Nm——毛管的極限分流孔數(shù)；Inthisformula:Nm:limitdrippernumbersofdriptape[△h2]——毛管的允許水頭差，m，[△h2]=β2[△h]，β2應經(jīng)過技術經(jīng)濟比較確定，對于平地β2可取0.55；

[Δh2]permitwaterheadlossofdriptape.[△h]——灌水小區(qū)允許水頭差m；[Δh]permitwaterheadlossofirrigationregion.d——毛管內(nèi)徑mm；d------innerradiusofdriptape,mmk——水頭損失擴大系數(shù)，一般為1.1～1.2；

qdk:waterheadlossenlargemodulus;commonlyis1.1～1.2.

qd:——滴頭設計流量L/h。qd:Designedflowrateofdriptape,L/h.確定毛管極限長度(Lm)Confirmoflimitlengthofthepipetape(Lm)Lm=Nm×Se根據(jù)毛管極限長度及條田的實際情況可確定毛管的實際鋪設長度。Confirmlimitlengthoflateral,calculatethereallengthoflateralaccordingtolimitlengthandrealsituationoffarmland.確定毛管的沿程水頭損失h毛（多孔管）Confirmofwaterheadlossalonglateral,h(porouspipe)式中：f、m、b——分別為摩阻系數(shù)，流量指數(shù)和管徑系數(shù)，可由表3-3查得；Inthisformula:f、m、bisrespectivelyattritionmodulus,flowrateindexandpiperadiusmodulus,youcanchoosetheparameterfromtable2.3-3:

N——出水孔個數(shù)；

N:numberofoutlet;

S0——進口至首孔的間距，m。S0:spacebetweenfirstemitterandthebeginningofthelateral,m確定毛管局部水頭損失

Confirmlocalwaterheadlossoflateral當參數(shù)缺乏時,毛管局部水頭損失可按沿程水頭損失的10%-20%計算。Take10%-20%ofwaterheadlossalongthelateralasthelocalwaterheadlossifnotoomuchparameters.

輔管、支管設計

Designforassistantpipelineandsubmain輔管、支管的選型Chooseassistantpipelineandlateral確定經(jīng)濟管徑Confirmeconomypipediameter式中：D——管內(nèi)徑，mm；Inthisformula:Dpipeinsidediameter,mmQ——管設計流量，m3/h；Q——pipedesignflowrate,m3/hI——經(jīng)濟水力坡度，支管、輔管沿程水頭損失的計算Calculatelateral、assistantpipewaterheadloss對于有輔助支管的滴灌系統(tǒng)，支管沿程水頭損失計算至最后一個給水閥，當只開一條或兩條輔管時，其沿程水頭損失計算公式為：Fordripirrigationsystemwithassistantsubmain,calculatewaterheadlossalongassistanttillthelastsupplyvalve.Whenopeningoneortwoassistantlateral,itscalculationformulaofwaterheadlossalongsubmainis:

支管的鋪設長度L，在系統(tǒng)分析的基礎上，用線性規(guī)劃或動態(tài)規(guī)劃的方法確定支管的水頭損失hf，然后反推算出管長LSubmainlengthL:afteranalyzingthesystem,getthelengthwithabackcalculationbylinearconfirmoflateralwaterheadlosshfuselinearityprogramordynamicprogram.管道沿程水頭損失計算系數(shù)、指數(shù)表

modulus、indexforwaterheadlossalongpipelinecalculation管材PipeFmb硬塑料管Hardplasticpipe0.4641.774.77微灌用聚乙烯管PEpipeformicroirrigation

d>8mm0.5051.754.75D≤8mmRe>23200.5951.694.69Re≤23201.7514支管局部水頭損失Calculatelocalwaterheadlossofsubmain當參數(shù)缺乏時，局部水頭損失可按沿程水頭損失的5%~10%計算Take5%-10%ofwaterheadlossalongthesubmainasthelocalwaterheadlossifparametersarenotenough.薄壁支管水頭損失計算Calculatewaterheadlossalongsubmainwiththinwall干管的設計Mainlinedesign

干管的沿程和局部水頭損失計算Calculatewaterheadlossalongsubmainwiththinwall沿程水損局部水損

CalculationformulaofCalculationformulaofwaterheadlossalongmainline

partwaterheadloss式中ζ為局部水頭損失系數(shù)。Informula:ζislocalwaterheadlossmodulus.

首部樞紐設計HeadControlDesign水源過濾及施肥設備選型Watersourcefiltrationandfertilizerequipmentselection

應根據(jù)水源水質(zhì)和滴頭抗堵塞能力選擇過濾設備型號，由于流道設計上的差異，各種灌水器對水質(zhì)的要求不同。若已知灌溉水中各種污物的含量，則可根據(jù)以下條件選配過濾設備：Selectfiltrationequipmentaccordingtoqualityofwaterresourceandemittercharacterofanti-clogging.Duetodifferenceonflowpassagedesign,emittersrequiredifferentwaterquality.Differentwaterqualitiesneeddifferenttreatment.

Ifweknowthecontentofimpurityintheirrigationwater,wecanselectfiltrationequipmentsbasedonfollowingconditions:當灌溉水中無機物含量小于10ppm或粒徑小于80μm時，宜選用砂石過濾器或篩網(wǎng)過濾器。Whenmineralcontentintheirrigationwaterislessthan10ppmorgraindiameterislessthan80μm,sandfilterorscreenfilterisbetter.灌溉水中無機物含量在10～100ppm之間，或粒徑在80～500μm之間時，宜先選用離心過濾器或篩網(wǎng)過濾器作初級處理，然后再選用砂石過濾器。Whenmineralcontentintheirrigationwaterisbetween10and100ppm,orgraindiameterisbetween80and500μm,centrifugalfilterorscreenfilterisasthefirstclass,screenfilterandsandfilterisbetterforsecondclass.灌溉水中無機物含量大于100ppm或粒徑大于500μm時，應使用沉淀池或離心過濾器作初級處理，然后再選用篩網(wǎng)或砂石過濾器。Whenmineralcontentintheirrigationwaterismorethan100ppmorgraindiameterbiggerthan500ppm,screenfilterorsettlingpondsareneededforprimaryfiltration,andthenscreenfilterorsandmediafilter.灌溉水中有機污物含量小于10PPm時，可用砂石過濾器或篩網(wǎng)過濾器。灌溉水中有機污物含量大于100PPm，應選用初級攔污篩作第一級處理，再選用篩網(wǎng)或砂石過濾器。Whenorganic