膜下滴灌系统的组成与规划设计（定稿）

膜下滴灌系统的组成与规划设计

TheComponentandDesignofDripIrrigationSystemunderMulchFilm

国家节水灌溉工程技术研究中心（新疆）NationalCenterofEfficientIrrigationEngineeringandTechnologyResearch-XinJiang何林望HeLinwang1、膜下滴灌系统的组成

ComponentofDripIrrigationSystemunderMulchFilm

水源工程Watersourceproject

首部枢纽Headofpivot

输配水管网Pipenetworksforwatertransportation

滴头及控制测量和保护装置

Emitters,pressureregulator,measuringmeterandprotectiondevices1.水源WaterSource2．水泵Pump3.供水管WaterSupplyPipe4.蓄水池Pond5.逆止阀BackflowPreventionDevice6.施肥开关Fertilizervalve7.灌水总开关IrrigationHeadValve

13.滴头Emitter14.毛管(滴灌带)Lateral(Dripline)15.滴灌支管Manifold16.尾部开关(电磁阀)ZoneValve(Electricalvalve)17.冲洗阀FlushValve18肥料罐FertilizerTank19.肥量调节阀FertilizerRegulator

20.施肥器FertilizerInjector

21.干管MainLine2、膜下滴灌系统设备

EquipmentofDripIrrigationSystemunderMulchFilm

2.1滴灌管（带）

Dripline(tape)柱状滴头Columnardriptape

微喷带

Micro

spraytape

压力补偿式滴头Pressurecompensatingdriptape微喷Micro-sprinkle2.2输配水管道

Pipesforwatertransportation

PVC干管PVCMainpipePE支管、辅管PESubmainLine

pipeandFeederLinepipe

2.3首部控制枢纽HeadControl

水泵Pump过滤设备Filtrationdevice12347568离心式过滤器CentrifugalFilterWateroutletwaterinlet3.罐体tanksandinletsandoutlet6.支架supportsand-inpotflushingoutletCentrifugalFilter网式过滤器ScreenFilter离心网式过滤器组合UnitedCentrifugalFilterandScreenFilter砂石过滤器SandFilter工作原理OperatingPrincipleInletShelfBodyFilterMediumOutlet叠片式过滤器DiscFilter施肥罐：FertilizerTank3.膜下滴灌系统的规划设计

ProjectPlanningandDesignofDripIrrigationSystemunderMulchFilm

Basicprincipleofprojectplanning滴灌工程的规划应与农田基本建设规划相结合Projectofdripirrigationshouldconsiderthebasicconstructionoffarmland.近期需要与远景发展规划相结合

Requirementinthenearfutureshouldconnectwithdevelopmentinthefuture.滴灌工程的规划应综合考虑工程的经济、社会和生态效益。

Projectofdripirrigationshouldtakeintoaccountbenefitsofeconomic,socialandecology.3.1.2规划的内容

Contentsofproject勘测收集基本资料Surveyandcollectbasicdata论证工程的必要性和可行性Evaluatenecessityandfeasibilityofproject确定工程的控制范围和规模

Ascertaincontrollingareaandscopeofproject选择适当的取水方式Chooseproperfetchingwatermode滴灌系统选型Choosedripirrigationsystem工程布置Projectdisposal做出工程概算Workoutprojectbudgetaryestimates3.1.3资料的收集

Data

collection地理位置与地形资料Geographicallocationandtopographydata土地与工程地质资料Soilandprojectgeologydata水文与气象资料Hydrologyandweatherdata农作物资料Cropdata水源与动力情况Watersourceanddrivercondition社会经济状况及农业发展规划方面的基本资料

Situationofsocialeconomyandagriculturedevelopmentproject3.2滴灌系统的布置

Layoutofdripirrigationsystem控制面积的确定Ascertainmentofcontrollingarea水源供水流量稳定且无调蓄能力时可用下式确定滴灌面积Usethefollowingformulatodecideirrigationarea,aswaterissupplyingstablyandnoadjustment:式中：intheformula：

A——可灌面积，hm2；irrigationarea，hm2；Q——可供流量，m3/h；flowrate，m3/h；Ia——设计供水强度，mm/d；designedwatersupplyintensity，Ia=Ea-P0Ea——设计耗水强度，mm/d；designedwaterconsumeintensity，mm/d；P0——有效降雨量，mm/d；efficiencyofrainfall，mm/d；t——水源每日供水时数，h/d；hourofwatersupplyeveryday，h/d；η——灌溉水利用系数。coefficientofirrigationwater.

水源有调蓄能力且调蓄容积已定时，可用下式确定滴灌面积Usethefollowingformulatodecideirrigationarea,aswatersourceisadjustableandadjustingcubageisfixed：

式中：intheformula：

K——塘坝复蓄系数，K=1.0—1.4；K——efficiencyofponddamrepeatedsavingwater，；η——蓄水利用系数，η=0.6—0.7；η——coefficientofsavingwater，η=0.6—0.7；V——蓄水工程容积，m3；V——watersavingprojectcubage，m3；Ii——灌溉季节各月的毛供水强度，mm/d；Ii——grosswatersupplyintensityofeverymonthinirrigationseason，mm/d；Ti——灌溉季节各月的供水天数，d。Ti——supplywaterdaynumberofeverymonthinirrigationseason，d.3.2.2常见的几种管网布置方式

Somefamiliarpipenetworkslayouts水源位于田块的中心，控制面积较大时，常采用一字形树枝装管网布置形式“一”disposaltreeformofpipenetworks,ascontrollingareaislargeorwatersourceislocatedincenterofthefield.“一”字形布置“一”disposalT形布置“T”disposal梳齿形布置Combformdisposal

3.3系统设计参数的确定

Ascertainmentofsystemdesignparameter

基本参数Basicparameter1、设计保证率Insurancerateofdesign2、灌溉水的利用率不低于90%Irrigationwateruseefficiencyisnotlessthan90%3、设计系统的日工作小时应根据不同水源和农业技术条件确定，一般不宜大于20hWorkhourofdesignedsystemaccordingtodifferentwatersourceandagriculturetechnicalcondition,anditisbetternottoworkmorethan20hours.4、滴头设计工作水头应取所选滴头的额定工作水头，或由滴头压力与流量关系曲线确定。Choosenominalworkingwaterheadasworkpressure,ordoaccordingtopressureandflowratecurveofemitter.5、设计耗水强度应采用作物耗水强度峰值，并应由当地试验资料确定。Designedconsumewaterintensity（Ea）：shouldadoptcropconsumewaterpeakvalue，localexperimentdatadecidetheEa.6、计划土壤湿润层深度，不同作物不同生育阶段的计划湿润层深度不一样，根据各地的经验确定。Planeddepthofwettedsoil（Z）：planeddepthofwettedsoilindifferentcropanddifferentgrowthstagearedifferent，accordingtodifferentlocalexperience.3.3.2灌溉制度

Irrigationscheme设计灌水定额：根据当地试验资料按下面公式之一计算Designirrigationquota：Accordingtolocalexperimentdatum,useoneofthereinafterformulastocalculate:m=0.1γZP(θmax-θmin)/ηOrm=0.1ZP(θmax-θmin)/η式中：intheformulas：

m——设计灌水定额mm；designirrigationquota(mm)；γ——土壤容重g/cm3；

γ——soildensityg/cm3，toselectaccordingtoFig.2.3-1；z——计划土壤湿润层深度m；z——thedepthofplannedwettedsoilm；P——湿润比%；P——percentageofwettedarea%；θmax、θmin——适宜土壤含水率上、下限（占干土重的百分比），θmax可取田间持水率的90%，θmin可取田间持水率的60%，可根据表2.3-1选用；θmax、θmin——upanddownlimitofwatercontent（weightpercentageindrysoil），θmaxreferto90%offieldmoisturecapacity，θminreferto60%offieldmoisturecapacity.Choosetheparameter；θmax、θmin——适宜土壤含水率上、下限（占土壤体积百分比）,θmax可取田间持水率的90%,θmin可取田间持水率的60%，可根据表2.3-1选用；θmax、θmin——upanddownlimitofwatercontent（cubagepercentageindrysoil），θmaxreferto90%offieldmoisturecapacity，θminreferto60%offieldmoisturecapacity.Choosetheparameter.η——灌溉水利用系数。η——irrigationwaterusecoefficient.表3-1不同土壤的物理特性表

Table3-1physicalcharacteristicsofdifferentsoil土壤质地Soilcharacteritisc容重Density（g/cm3）田间持水量Fieldmoisturecapacity

凋萎系数Wiltingcoefficient

重量含水率WCWM(%)体积含水率CCWM（%）重量含水率WCWM(%)体积含水率CCWM

%）砂土Sand1.45-1.8016-2026-32

砂壤土Sandysoil

1.36-1.5422-3032-404-65-9轻壤土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轻粘土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

设计灌水周期：可按下式计算Designirrigationintervalcalculateaccordingtothereinafterformula:T=（m/Ea）η式中：T——设计灌水周期d；Intheformula：T——designedirrigationcycled；Ea——设计耗水强度mm/d。Ea——designedwaterconsumeintensitymm/d.按上式求得的值为作物需水高峰期的灌水周期。Withforegoingformula,wecouldworkoutirrigationwatercycleasthecycleatpeakofcroprequirementwater.一次灌水延续时间Durationofirrigation

t=m•Se•Sr/（ηqd）式中：t——一次灌水延续时间h；intheformula：t——durationofoneirrigation(h)；qd——设计滴头流量l/h。qd——designeddischargeofemitterl/h.灌水次数与灌水总量的确定irrigationtimesandgrossirrigationquality

3.3.3滴灌灌水均匀度

Irrigationuniformityofdripirrigation

滴灌均匀系数Uniformitycoefficientofdripirrigation

灌水器设计允许流量偏差率qv应不大于20%，设计灌水均匀度不应低于0.95。Designedallowableflowratedeviation(qv)islowerthan20%，designirrigationuniformityisbetterthan0.95.灌水小区允许水头偏差Permitflowratedeviationofirrigationblock滴头工作水头偏差率hV与流量偏差率qV之间的关系可用下式表示：Wecouldusethereinafterformulatoshowrelationofdeviationrateofemitterworkwaterhead(hv)andpermitflowratedeviation(qv)：式中：X——滴头流态指数。intheformula：X——emitterdischargeexponent。灌水小区允许水头偏差按下式计算：Wecanworkoutpermitflowratedeviationofirrigationdistrictwiththereinafterformula：[ΔH]=hV×hd式中：[ΔH]——灌水小区允许水头偏差，m；intheformula：[ΔH]——permitflowratedeviationofirrigationdistrict，m；hd——设计滴头工作水头，m。hd——designemitterworkwaterhead，m.3.4.滴灌系统设计

Designationofdripirrigationsystem毛管设计Driptapedesign1、滴灌带的选型Driptapespecification2、水平毛管极限滴头个数的确定Confirmlimitdrippernumbersofdriptape式中：Nm——毛管的极限分流孔数；Inthisformula:Nm:limitdrippernumbersofdriptape[△h2]——毛管的允许水头差，m，[△h2]=β2[△h]，β2应经过技术经济比较确定，对于平地β2可取0.55；

[Δh2]permitwaterheadlossofdriptape.[△h]——灌水小区允许水头差m；[Δh]permitwaterheadlossofirrigationregion.d——毛管内径mm；d------innerradiusofdriptape,mmk——水头损失扩大系数，一般为1.1～1.2；

qdk:waterheadlossenlargemodulus;commonlyis1.1～1.2.

qd:——滴头设计流量L/h。qd:Designedflowrateofdriptape,L/h.确定毛管极限长度(Lm)Confirmoflimitlengthofthepipetape(Lm)Lm=Nm×Se根据毛管极限长度及条田的实际情况可确定毛管的实际铺设长度。Confirmlimitlengthoflateral,calculatethereallengthoflateralaccordingtolimitlengthandrealsituationoffarmland.确定毛管的沿程水头损失h毛（多孔管）Confirmofwaterheadlossalonglateral,h(porouspipe)式中：f、m、b——分别为摩阻系数，流量指数和管径系数，可由表3-3查得；Inthisformula:f、m、bisrespectivelyattritionmodulus,flowrateindexandpiperadiusmodulus,youcanchoosetheparameterfromtable2.3-3:

N——出水孔个数；

N:numberofoutlet;

S0——进口至首孔的间距，m。S0:spacebetweenfirstemitterandthebeginningofthelateral,m确定毛管局部水头损失

Confirmlocalwaterheadlossoflateral当参数缺乏时,毛管局部水头损失可按沿程水头损失的10%-20%计算。Take10%-20%ofwaterheadlossalongthelateralasthelocalwaterheadlossifnotoomuchparameters.

辅管、支管设计

Designforassistantpipelineandsubmain辅管、支管的选型Chooseassistantpipelineandlateral确定经济管径Confirmeconomypipediameter式中：D——管内径，mm；Inthisformula:Dpipeinsidediameter,mmQ——管设计流量，m3/h；Q——pipedesignflowrate,m3/hI——经济水力坡度，支管、辅管沿程水头损失的计算Calculatelateral、assistantpipewaterheadloss对于有辅助支管的滴灌系统，支管沿程水头损失计算至最后一个给水阀，当只开一条或两条辅管时，其沿程水头损失计算公式为：Fordripirrigationsystemwithassistantsubmain,calculatewaterheadlossalongassistanttillthelastsupplyvalve.Whenopeningoneortwoassistantlateral,itscalculationformulaofwaterheadlossalongsubmainis:

支管的铺设长度L，在系统分析的基础上，用线性规划或动态规划的方法确定支管的水头损失hf，然后反推算出管长LSubmainlengthL:afteranalyzingthesystem,getthelengthwithabackcalculationbylinearconfirmoflateralwaterheadlosshfuselinearityprogramordynamicprogram.管道沿程水头损失计算系数、指数表

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支管局部水头损失Calculatelocalwaterheadlossofsubmain当参数缺乏时，局部水头损失可按沿程水头损失的5%~10%计算Take5%-10%ofwaterheadlossalongthesubmainasthelocalwaterheadlossifparametersarenotenough.薄壁支管水头损失计算Calculatewaterheadlossalongsubmainwiththinwall干管的设计Mainlinedesign

干管的沿程和局部水头损失计算Calculatewaterheadlossalongsubmainwiththinwall沿程水损局部水损

CalculationformulaofCalculationformulaofwaterheadlossalongmainline

partwaterheadloss式中ζ为局部水头损失系数。Informula:ζislocalwaterheadlossmodulus.

首部枢纽设计HeadControlDesign水源过滤及施肥设备选型Watersourcefiltrationandfertilizerequipmentselection

应根据水源水质和滴头抗堵塞能力选择过滤设备型号，由于流道设计上的差异，各种灌水器对水质的要求不同。若已知灌溉水中各种污物的含量，则可根据以下条件选配过滤设备：Selectfiltrationequipmentaccordingtoqualityofwaterresourceandemittercharacterofanti-clogging.Duetodifferenceonflowpassagedesign,emittersrequiredifferentwaterquality.Differentwaterqualitiesneeddifferenttreatment.

Ifweknowthecontentofimpurityintheirrigationwater,wecanselectfiltrationequipmentsbasedonfollowingconditions:当灌溉水中无机物含量小于10ppm或粒径小于80μm时，宜选用砂石过滤器或筛网过滤器。Whenmineralcontentintheirrigationwaterislessthan10ppmorgraindiameterislessthan80μm,sandfilterorscreenfilterisbetter.灌溉水中无机物含量在10～100ppm之间，或粒径在80～500μm之间时，宜先选用离心过滤器或筛网过滤器作初级处理，然后再选用砂石过滤器。Whenmineralcontentintheirrigationwaterisbetween10and100ppm,orgraindiameterisbetween80and500μm,centrifugalfilterorscreenfilterisasthefirstclass,screenfilterandsandfilterisbetterforsecondclass.灌溉水中无机物含量大于100ppm或粒径大于500μm时，应使用沉淀池或离心过滤器作初级处理，然后再选用筛网或砂石过滤器。Whenmineralcontentintheirrigationwaterismorethan100ppmorgraindiameterbiggerthan500ppm,screenfilterorsettlingpondsareneededforprimaryfiltration,andthenscreenfilterorsandmediafilter.灌溉水中有机污物含量小于10PPm时，可用砂石过滤器或筛网过滤器。灌溉水中有机污物含量大于100PPm，应选用初级拦污筛作第一级处理，再选用筛网或砂石过滤器。Whenorganic