Unit 37VentilationTextAccordingtotheventilationsystemofthepower： Accordingtotheventilationsystemofpower,ventilationmodecanbedividedintonaturalventilationandmechanicalventilation.

1.Naturalventilation Naturalventilationistorelyonindoorandoutdoorairtemperaturedifferencecausedbythehotpressingandoutdoorwindpressurecausedbythewaytorealizetheairventilation. 1）Undertheactionofthermalnaturalventilation Adiagraminfigure1forusingthermalnaturalventilation,duetothehighairtemperatureintherooms,densityissmall,soproducedakindofupwardforce,tomaketheroomairrisesanddischargefromtheupperwindow,outdoorcoldairintotheindoorfromtheroombelowtheWindowsoftheholesorcracks.Undertheactionofthisventilationmodeiscalledthermalnaturalventilation.Figure1NaturalventilationunderthehotactionText 2）thenaturalventilationundertheactionofwindpressure Figure2isanaturalventilationdiagrambytheactionofwindpressure,Airflowentertheroomfromthewindowsanddoorswhichonthebuilding’swindward.AtthesametimeSqueezeouttheindoorairfromthewindowsanddoorswhichonthebuilding’sleeside.Therefore,akindofnaturalventilationisformedintheroomcausedbywind.Thiswayofventilationiscalledthenaturalventilationundertheactionofairpressure. NaturalventilationcanbedividedintoOrganizednaturalventilationandunorganizednaturalventilation.TheOrganizednaturalventilationisconductedbytheworkshopsSidewindowandskylights,Bycontrollingitsopeningdegree,Adjusttheairinflowanddisplacement;Theunorganizednaturalventilationisconductedbythedoorsandwindowsaperture.Figure2NaturalventilationunderwindpressureText Therearemanyfactorswhichcanaffectthenaturalventilation,Suchasindoorandoutdoorairtemperature,outdoorairflowvelocityandflowdirection,shopWindowsanddoorsholessizeandlocation.SotheAirvolumeisconstantlychanging.Soweneedtoconstantlyadjusttheairoutletopeningdegreeaccordingtothespecificsituationtometthedemand. Naturalventilationischaracterizedbysmallinvestment,goodeconomy,buttheeffectandapplicablescopeissmall,ItismainlyusedforIndustrialworkshop;Becauseoftheuncertaintyofthenaturalwind,So,Undernormalcircumstances,weregardthenaturalventilationbywindeffectswhendoingthedesign.

2.Mechanicalventilation

Mechanicalventilationistheuseofpowergeneratedbytheventilators,ventilatingmode.Figure3istheuseoftheexhaustpipeexhaustuniformly.Figure4iswilldrainawayharmfulgasesfromseverallocallocations. Figure3uniformexhaustsystemFigure4 localexhaustsystemTextFigure5isthedustremovalsystem,thedustremovalsystemcanalsobeusedtorecyclepowder.Figure6systemformechanicalventilation,outdoorairundertheactionoffanbyblindsintotheintakechambers.Afterhitchesininletchambersfilter,heaterheating,throughtheductintotheventilationroom.Figure5 thedustremovalsystem1—Pestscollector；2—airduct；3—fan；4—dustcollectorFigure6 mechanicalventilationsystem1—theshutters；2—airfilter；3—airheater；4—theventilator；5—duct；6—airtreatmentroom；7—motor；8—airdistributorText

Accordingtotheroleoftheventilationsystem: Accordingtothescopeoftheventilationsystem,ventilationsystemcanbedividedintocomprehensiveventilationandlocalventilation. 1.Thecomprehensiveventilation Comprehensiveventilationisintheroomthoroughlyventilatedtakeabreath.Thecomprehensiveventilation′spurposeistodilutethepollutantsintheairandprovidetheheatoftheroomneeds.Characterizedbyawiderange,largeairvolume,highinvestmentandoperatingcost,whenusinglocalventilationmodeisdifficulttoensurehygienestandardsadopted. Comprehensiveventilationcanmakeuseofmechanicalventilation,alsocanbeusetonaturalventilationtoachieve,thecomprehensiveventilationcanbedividedintocomprehensiveexhaustandoverallsupply.

2.Localventilation Localventilationcanbedividedintolocalexhaustandlocalsupply.TextLocalexhaustisafterdischargetocapture,purifythepestsontheoutside,Andlocalairsupplyareprocessed,conformtotherequirementsoftheairtothelocalworkingplace,toensuretheairconditionoflocalarea. Thecharacteristicsoflocalventilationisthepestcontroleffectisgood,smallvolume,smallinvestment,lowoperatingcost.Accordingtothecharacteristicsoftheventilationsystem: Accordingtothecharacteristicsoftheventilationsystem,ventilationsystemcanbedividedintoairsupplyandexhaustair. 1.Thesupplyair Thefreshairintotheindooriscalledsupplyair. 2.Exhaustair Thefoulairinsidetheroomafterprocessingtomeetdischargestandardsemissionscalledexhaust.Inactualengineering,fromtheperspectiveoftechnicaleconomy,thepriorityshouldbegiventothenaturalventilation,whenitcannotsatisfytheneedtoadoptmechanicalventilation;Giveprioritytowithlocalventilation,adoptsthecomprehensiveventilationwhenitcannotsatisfytheneed. Inpracticalengineering,usingawayofventilationisoftencannotsatisfytheneedoftheeffect,isusuallyavarietyofventilationmethodisusedincombination.Louver n.百葉窗Piece n.(通風(fēng))部件control

valve 調(diào)節(jié)閥

control

velocity 控制風(fēng)速

controlled

natural

ventilation 有組織自然通風(fēng)

controlled

plant 調(diào)節(jié)對象cross-ventilation 穿堂風(fēng)exhaust

air

rate 排風(fēng)量

exhaust

fan 排風(fēng)機(jī)

local

air

suppiy

system 局部送風(fēng)系統(tǒng)

local

exhaustventilation

(LEV) 局部排風(fēng)NewWordsandPhrasesNotes（1）Naturalventilationistorelyonindoorandoutdoorairtemperaturedifferencecausedbythehotpressingandoutdoorwindpressurecausedbythewaytorealizetheairventilation. 自然通風(fēng)是依靠室內(nèi)和室外空氣溫差引起的熱壓及室外風(fēng)壓造成的方式實現(xiàn)空氣通風(fēng)。（2）Therearemanyfactorswhichcanaffectthenaturalventilation,Suchasindoorandoutdoorairtemperature,outdoorairflowvelocityandflowdirection,shopWindowsanddoorsholessizeandlocation. 有許多影響自然通風(fēng)的因素，例如，室內(nèi)和室外空氣溫度、室外空氣流速和流向、門和窗孔的大小及位置等。（3）Accordingtothescopeoftheventilationsystem,ventilationsystemcanbedividedintocomprehensiveventilationandlocalventilation. 根據(jù)通風(fēng)系統(tǒng)的作用范圍，通風(fēng)系統(tǒng)可以分為全面通風(fēng)和局部通風(fēng)。（4）Thecharacteristicsoflocalventilationisthepestcontroleff