建筑给排水_外文文献翻译适用于毕业论文外文翻译中英文对照.doc

建筑给排水_外文文献翻译适用于毕业论文外文翻译中英文对照.doc

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本科毕业设计

外文文献及译文

文献、资料题目：

Sealedbuildingdrainage

andventsystems

文献、资料来源：

国道数据库

文献、资料发表（出版）日期：

2005.9.12

院（部）：

市政与环境工程学院

专业：

给水排水工程

班级：

姓名：

学号：

指导教师：

翻译日期：

2012.06

山东建筑大学毕业设计外文文献及译文

外文文献：

Sealedbuildingdrainageandventsystems

—anapplicationofactiveairpressuretransientcontrolandsuppression

Abstract

Theintroductionofsealedbuildingdrainageandventsystemsisconsideredaviablepropositionforcomplexbuildingsduetotheuseofactivepressuretransientcontrolandsuppressionintheformofairadmittancevalvesandpositiveairpressureattenuatorscoupledwiththeinterconnectionofthenetwork'sverticalstacks.

Thispaperpresentsasimulationbasedonafour-stacknetworkthatillustratesflowmechanismswithinthepipeworkfollowingbothappliancedischargegenerated,andsewerimposed,transients.Thissimulationidentifiestheroleoftheactiveairpressurecontroldevicesinmaintainingsystempressuresatlevelsthatdonotdepletetrapseals.

Furthersimulationexerciseswouldbenecessarytoprovideproofofconcept,anditwouldbeadvantageoustoparallelthesewithlaboratory,andpossiblysite,trialsforvalidationpurposes.Despitethiscautiontheinitialresultsarehighlyencouragingandaresufficienttoconfirmthepotentialtoprovidedefinitebenefitsintermsofenhancedsystemsecurityaswellasincreasedreliabilityandreducedinstallationandmaterialcosts.

Keywords:

Activecontrol;Trapretention;Transientpropagation

Nomenclature

C+-——characteristicequations

c——wavespeed,m/s

D——branchorstackdiameter,m

f——frictionfactor,UKdefinitionviaDarcyΔh=4fLu2/2Dg

g——accelerationduetogravity,m/s2

K——losscoefficient

L——pipelength,m

p——airpressure,N/m2

t——time,s

u——meanairvelocity,m/s

x——distance,m

γ——ratiospecificheats

Δh——headloss,m

Δp——pressuredifference,N/m2

Δt——timestep,s

Δx——internodallength,m

ρ——density,kg/m3

ArticleOutline

Nomenclature

1.Introduction—airpressuretransientcontrolandsuppression

2.Mathematicalbasisforthesimulationoftransientpropagationinmulti-stackbuildingdrainagenetworks

3.Roleofdiversityinsystemoperation

4.Simulationoftheoperationofamulti-stacksealedbuildingdrainageandventsystem

5.Simulationsignconventions

6.Waterdischargetothenetwork

7.Surchargeatbaseofstack1

8.Sewerimposedtransients

9.Trapsealoscillationandretention

10.Conclusion—viabilityofasealedbuildingdrainageandventsystem

1.Airpressuretransientsgeneratedwithinbuildingdrainageandventsystemsasanaturalconsequenceofsystemoperationmayberesponsiblefortrapsealdepletionandcrosscontaminationofhabitablespace[1].Traditionalmodesoftrapsealprotection,basedontheVictorianengineer'sobsessionwithodourexclusion[2],[3]and[4],dependpredominantlyonpassivesolutionswhererelianceisplacedoncrossconnectionsandverticalstacksventedto

atmosphere[5]and[6].Thisapproach,whilebothprovenandtraditional,hasinherentweaknesses,includingtheremotenessoftheventterminations[7],leadingtodelaysinthearrivalofrelievingreflections,andthemultiplicityofopenrooflevelstackterminationsinherentwithincomplexbuildings.Thecomplexityoftheventsystemrequiredalsohassignificantcostandspaceimplications[8].

Thedevelopmentofairadmittancevalves（AAVs）overthepasttwodecadesprovidesthedesignerwithameansofalleviatingnegativetransientsgeneratedasrandomappliancedischargescontributetothetimedependentwater-flowconditionswithinthesystem.AAVsrepresentanactivecontrolsolutionastheyresponddirectlytothelocalpressureconditions,openingaspressurefallstoallowareliefairinflowandhencelimitthepressureexcursionsexperiencedbytheappliancetrapseal[9].

However,AAVsdonotaddresstheproblemsofpositiveairpressuretransientpropagationwithinbuildingdrainageandventsystemsasaresultofintermittentclosureofthefreeairpaththroughthenetworkorthearrivalofpositivetransientsgeneratedremotelywithinthesewersystem,possiblybysomesurchargeeventdownstream—includingheavyrainfallincombinedsewerapplications.

Thedevelopmentofvariablevolumecontainmentattenuators[10]thataredesignedtoabsorbairflowdrivenbypositiveairpressuretransientscompletesthenecessarydeviceprovisiontoallowactiveairpressuretransientcontrolandsuppressiontobeintroducedintothedesignofbuildingdrainageandventsystems,forboth‘standard’buildingsandthoserequiringparticularattentiontobepaidtothesecurityimplicationsofmultiplerooflevelopenstackterminations.Thepositiveairpressureattenuator（PAPA）consistsofavariablevolumebagthatexpandsundertheinfluenceofapositivetransientandthereforeallo