夏季通風(fēng)系統(tǒng)

TUNNELVENTILATION

縱向通風(fēng)

September2011BernardGreenDISCUSSIONTOPICS

議題ClosedEnvironmentHouses

密閉環(huán)境式雞舍WindChill

風(fēng)冷效應(yīng)TunnelVentilationDesign

縱向通風(fēng)系統(tǒng)設(shè)計(jì)CoolingSystems

冷卻系統(tǒng)RelativeHumidity

相對濕度EvaporativeCooling

蒸發(fā)冷卻OperatingaCoolingSystem

操作冷卻系統(tǒng)OperatingTunnelVentilatedHouses

操作縱向通風(fēng)雞舍HotWeatherPreparation

炎熱季節(jié)前的準(zhǔn)備工作CLOSEDENVIRONMENTHOUSES

密閉式雞舍CommonlyknownasTunnelVentilation(TV)

通常知為縱向通風(fēng)For(effective)temperaturecontrolinhotweather

夏季有效控制溫度Takesplacedownlengthofhouse

整個(gè)雞舍內(nèi)都在運(yùn)作Exhaustfansatonegableend

排風(fēng)機(jī)安置在雞舍末端邊墻上Longinletsineachsidewallatoppositeend

另一端兩側(cè)有長的進(jìn)風(fēng)口Airispulleddownlengthofhouse

空氣從一端拉到另一端Coolingeffectofairmovement(windchill)

空氣運(yùn)動的冷卻效果（風(fēng)冷）Fansvaryairspeedandeffect

風(fēng)機(jī)效能決定風(fēng)速和效果TunnelVentilation

縱向通風(fēng)WINDCHILL

風(fēng)冷效應(yīng)ProbablythemostimportantfactorinTV

縱向通風(fēng)中最重要的因素Coolingeffectfromairmovementonthebirds

空氣運(yùn)動對雞只的冷卻效果Dependson:birdage,drybulbtemperature,airspeed,RH

取決于：雞只日齡，干球溫度，空氣速度，相對濕度Remember-Controllerprobe,drybulbthermometercannotmeasurewindchill

記住

–控制器的探針，干球溫度計(jì)無法測量風(fēng)冷效應(yīng)Variouswindchillchartsavailable

可得到不同風(fēng)冷效應(yīng)的圖表HowmanyfansshouldIuse?

我應(yīng)該使用多少臺風(fēng)機(jī)呢？Always

basethefinaldecisiononbirdcomfort

雞只舒適決定一切WindchillExample

風(fēng)冷例證0.51.01.52.02.53.0AirVelocity(m/s)8.05.53.51.09.06.54.52.0WindChill(°C)OlderBirdsYoungerBirds-ExampleTUNNELVENTILATIONDESIGN

縱向通風(fēng)設(shè)計(jì)Twofactorstoconsider:

要考慮兩個(gè)因素：1. Airspeed

空氣速度fancap.[m3/hr]=speed[m/s]xCSA[m2]x3600

風(fēng)機(jī)排風(fēng)量（立方米/小時(shí)）=速度（米/秒）xCSA(平方米)x3600CSA=crosssectionarea

CSA=橫截面積CSA=(WxH)+(?WxR)

CSA=

（寬X高）+（1/2寬XR）3600=convertm/stom/hr

3600=米/秒變成米/小時(shí)NarrowhousepreferredforTV

狹窄的雞舍最適合用縱向通風(fēng)系統(tǒng)Selectfanbasedon

operatingpressure

根據(jù)工作壓力選擇風(fēng)機(jī)FanOperatingPressure

風(fēng)機(jī)的工作壓力?P?P?P?PFanOperatingPressure=?P+?P+?P+?P風(fēng)機(jī)工作壓力?P?PFanPerformanceExample

風(fēng)機(jī)性能12mHouse–8x50”fans40500m3/hr→2,65m/s38000m3/hr→2,54m/s34500m3/hr→2,30m/s32000m3/hr→2,10m/sFanPerformanceExample

風(fēng)機(jī)性能例證PressurePa01225313750FanCapm3/hr431854063538084363843468430434PressureInWC0.000.050.100.120.150.22. Temperaturegradientfrominlettofans

進(jìn)風(fēng)口到出風(fēng)口的溫度梯度Veryimportantinlong,widehouses

對長而寬的雞舍尤為重要Considerbirdgeneratedheat

要考慮雞只也產(chǎn)生熱Radiantheatgainfromsun(throughroof)

來自太陽（穿過屋頂）輻射熱的增加Keeptemperaturerise<2,5°C

保持溫度上升小于2.5攝氏度.Totalinletareamustmatchfullfanoperatingcapacity

整個(gè)進(jìn)風(fēng)口面積必須與所有風(fēng)機(jī)的排放量相匹配.AirDeflector風(fēng)擋AirDeflectors

風(fēng)擋Usedinhouseswithlowairspeedorhighroof

用于風(fēng)速低或高屋頂雞舍AirDeflectorshave2effects:

風(fēng)擋具有兩個(gè)效用:1. IncreaseairspeedbyreducingCSA

通過降低截面積提高風(fēng)速2. Makesairmovementmoreuniform

使空氣運(yùn)動更加均勻Evensoutairspeedfromsidewalltosidewall

均衡雞舍內(nèi)一側(cè)邊墻至另一側(cè)邊墻的風(fēng)速AirDeflectors

風(fēng)擋Installation

安裝Installnomorethan10mapart

安裝間距不要超過10米Donotinstalltoolow!

不要安裝的過低!Minimumheight±2,4m

最低高度約2.4米Toolowcanincreasepressureonfansandhaveoppositeeffect

安裝過低會對風(fēng)機(jī)增大壓力,會產(chǎn)生相反效果.

COOLINGSYSTEMS

冷卻系統(tǒng)Atsomestagewindchillisn’tenough

某些階段風(fēng)冷效應(yīng)并不夠Airmustthenbecooled

所以空氣必須要進(jìn)行冷卻Options:

選擇:1. Spray(foggers)

噴霧2. CoolingPads

濕簾CoolingPads

濕簾Calculatingpadarea:

計(jì)算濕簾面積MustknowtotaloperatingTVfancapacity

必須知道縱向通風(fēng)雞舍總的風(fēng)機(jī)排風(fēng)能力padarea[m2]=fancap[m3/hr]÷2,03[m/s]÷3600

濕簾面積(平方米)=風(fēng)機(jī)排風(fēng)量(立方米/小時(shí))÷2.3(米/秒)÷36002,03m/s

designairspeedthru150mmpad

通過150毫米厚濕簾風(fēng)速1,27m/s

designairspeedthru100mmpad

通過100毫米厚濕簾風(fēng)速3600

conversionfromm3/hrtom3/s

小時(shí)立方米轉(zhuǎn)成秒立方米Installequallyoneitherside(atendofthehouse)

對等安裝一端兩側(cè)Ensurepadisinstalledincorrectorientation

確保濕簾按正確方位安裝Preferabletoinstalloncoolingpadroom

最好安裝濕簾間Allowspressurecontrolafterpad

空氣通過濕簾后壓力可控制Easiertosealinwinter(veryimportant!)

冬季便于密封（特別重要）66%74%24CoolingPadOrientation

濕簾方位CoolingPadRoom

濕簾間（濕簾小屋）CoolingPad濕簾(150mm)WeightedCurtain自重卷簾RackandPinionInlet帶框架擋板的進(jìn)風(fēng)口RELATIVEHUMIDITY

相對濕度Comparisonofamountofwaterintheairatacertaintemperature,relativetomaximumpotentialamountatsametemperature

Coldair

canholdlittlemoisture

冷空氣=含水分較少Hotair

canholdmoremoisture

熱空氣=含水分較多Astemperatureincreases,RHdecreases

隨著溫度上升，相對濕度降低Astemperaturedecreases,RHincreases

同上相反TemperatureRHEVAPORATIVECOOLING

蒸發(fā)冷卻Whatisit??Howdoesitwork??

這是什么？怎么工作的？Nothingtodowithwarmairagainstcoldwater

與暖空氣與冷水作用無關(guān)Nothingtodowithcoldwateronthebirds

與冷水和雞只無關(guān)Little(nothing)todowithwatertemperature

與水溫幾乎沒關(guān)系A(chǔ)chievedbyatransferofenergy(heat)fromthehotairtothewater

將熱空氣中的熱能轉(zhuǎn)換成水Airgivesenergytowater

coolerair

空氣將能量給予水分

較涼的空氣Waterabsorbsenergy

evaporates

水分吸收能量

蒸發(fā)Amountofcoolingpossibledependsonoutsidewetbulbtemp(RH)

冷卻的量取決于外界的濕球溫度（相對濕度）Dryenvironment(lowRH)

veryeffective

干燥的環(huán)境（較低的相對濕度）

效果非常好CoolingPotential

冷卻潛能ΔT=MaximumcoolingpossibleCoolingpadis±75%efficient,soActualcooling=0,75xΔTThiswillbethetemperaturerightatthepadDryBulbWetBulbΔTΔTΔTsmallHighRH(humid)SmallcoolingpotentialHumidclimateEarlymorningLateafternoon,eveningΔTbigLowRH(dry)BiggercoolingpotentialDryclimateDuringpeaktemperatureBirdsandEvaporativeCooling

雞只與蒸發(fā)冷卻Whenabirdisheatstressed,itlosesheatintwo

雞受熱應(yīng)激時(shí)，兩種釋熱：ways:1. Convection,conduction,radiation(airmovement)

對流，傳播，散發(fā) Occursduringinitialstagesofheatstress

熱應(yīng)激最初階段發(fā)生2. Evaporativecooling

蒸發(fā)冷卻Whenairmovementisnolongeradequate

空氣運(yùn)動不再起作用時(shí)Evaporativecoolingtakesplaceinthebird

雞只開始蒸發(fā)冷卻Asthebirdbreathes,airpassesoverthewetsurfacesofitsrespiratorysystem

隨著雞只呼吸，空氣經(jīng)過其呼吸系統(tǒng)潮濕的表面Likeacoolingpad,moistureisevaporated

就像濕簾，水分被蒸發(fā)Effectisincreasedbypanting(upto250/min.)

急速喘氣增加效果250/分LowRHeasiertoloseheat

相對濕度低

較容易釋放熱能OPERATINGACOOLINGSYSTEM

操作冷卻系統(tǒng)EffectivenessofbirdscoolingsystemdependsonRHofairaroundit

冷卻系統(tǒng)的效果取決于周邊空氣中的相對濕度IfRHlow

effective

如果相對濕度低

有效果IfRHhigh

ineffective(canleadtomortality)

如果相對濕度高

無效果（可導(dǎo)致雞只死亡）RuleofThumb(guideline):

法則（指導(dǎo)）IfhouseRH>70%,switchcoolingOFF

如果雞舍RH>

70%，關(guān)掉濕簾Temperaturewillincrease,RHwilldecrease

溫度上升，RH下降CANNOT

operatecoolingontemperaturealone!MUST

operateoncombinationofTempandRH不能只是根據(jù)溫度來操作濕簾必須綜合考慮溫度和相對濕度OPERATINGTVHOUSES

管理縱向通風(fēng)系統(tǒng)的雞舍Usefanstoregulateairspeed,windchill,birdcomfort

利用風(fēng)機(jī)調(diào)節(jié)風(fēng)速，風(fēng)冷效應(yīng)和雞只舒適程度Ifthebirdsareallsittingflat,theremaybetoomuchairmovement

如果雞只全部臥在地上，有可能是風(fēng)速太大。Beextremelycarefulwithyoungchicks

對于年輕雞只要格外小心Tunnelinletmustbepressurecontrolled

縱向通風(fēng)的進(jìn)風(fēng)口必須靠壓力控制NEVER

operatefansonlyondrybulbtemperature

切勿只靠干球溫度操作風(fēng)機(jī)Thermometers,sensorscan’tfeelwindchill

溫度計(jì)和感應(yīng)器無法感覺到風(fēng)冷效應(yīng)Watchbirdcomfort(don’tventilateforhumancomfort)觀察雞只舒適（通風(fēng)不是為了人員的舒適）Thebirdswilltellyouiftheyarehot,cold,comfortable

雞只會告訴你是否冷熱，是否舒適。Whenallfansareon,onlythenintroducecooling

所有風(fēng)機(jī)運(yùn)轉(zhuǎn)之后再開啟濕簾HouseRH>70%

switchcoolingOFF

RH大于70%，關(guān)閉濕簾。IfRHdropsbelow70%,canswitchbackON

如RH低于70%，再重新開啟濕簾Moderncontrolsdothisautomatically

現(xiàn)代控制系統(tǒng)都是自動控制。OPERATINGTVHOUSES

管理縱向通風(fēng)雞舍ThepurposeofacoolingsystemisNOTtoreducetemperaturetothesetpoint

冷卻系統(tǒng)的目的不是把溫度降到設(shè)定點(diǎn)。ItistoHOLDthetemperaturewherethebirdswerelastcomfortable

只是把溫度控制在以往雞只感到舒適的范圍。WhenRHishigh,airvolume/exchangeiscritical

相對濕度高時(shí)，空氣量/交換量十分重要。Movegentlythroughthehouseandgetbirdstostand,releasingheatload

空氣較溫和地通過雞舍，使雞只站立起來，釋放積蓄的熱能。ReleaseentireheatloadbeforeswitchingtoCrossVentilation(minimumventilation)

啟動橫向通風(fēng)系統(tǒng)（最小通風(fēng)系統(tǒng)）之前，要排除全部積蓄的熱能。PoorlyDesignedTunnelVentilationSystem

設(shè)計(jì)差的縱向通風(fēng)系統(tǒng)NoAirMovement0,4m/s0,8m/s1,3m/sAirExchangeRate=1,5minutes空氣交換率=1.5分鐘Canexpectheatst