1、Good is good, but better carries it.精益求精，善益求善。Airconditioning1-Airconditiong汽車空調窗體底端TherefrigerantcycleThisisthefirstinaseriesofarticlestogivethetechnicianaclearunderstandingoftheautomotiveA/Csystem.汽車空調制冷循環這是本系列文章的第一篇。此系列旨在讓技術人員們對于汽車空調系統（簡稱汽車A/C系統）有一個清晰的認識。Here,welookattherefrigerantcycle,andthebas

2、icprinciplesassociatedwiththeheattransferaroundthethermalexpansionvalvetype.在此，我們將介紹一下制冷循環系統，和一些與熱力膨脹閥式制冷系統類型的熱轉移相關的基本原則。A/Csystem.TwopointsthatarecriticaltotheunderstandingoftheA/Csystemaretheroutethroughwhichtherefrigerantflowsandthedifferingstatestherefrigerantisinasittravelsaroundthecircuit.A/C系

3、統有兩點對于理了解解A/C系統的運行非常關鍵，即制冷劑流動的線路和制冷劑在環路中循環時的不同狀態。Agreatstartingpointfortheunderstandingofthisisatthecompressor.科技類英語翻譯論文了解這些的一個很好的最好切入點就是壓縮機。Commonly,A/Ccompressorscontainreciprocatingpistons.通常A/C壓縮機都包含一些往復式活塞壓縮機都有一些往復式活塞。Asthepistontravelsinonedirection,throughaonewayvalve,itdrawsintherefrigerantg

4、asfromthelowpressuresideofthecircuit.活塞向一個方向移動時，環路中低壓端的氣態制冷劑通過一個單向閥，循環中低壓端的氣態制冷劑被吸入進來。Thepistonthentravelsbackintheotherdirectionandcompressestherefrigerantgascausingalargeincreaseinpressure.活塞然后向反方向移動，壓縮氣態制冷劑，引起壓強急劇升高。Oncethepressurereachesaspecificthresholditwillovercomeasecondonewayvalveandallowt

5、henowhighpressurerefrigerantgastoexitthecompressorandintothehighpressuresideoftherefrigerantcircuit.一旦壓強達到臨界點，它將迫使第二個單向閥打開，此時高氣壓中的氣態制冷劑從壓縮機中被釋放出來，進入制冷循環的高壓端進入制冷環路的高壓端。Thereisarelationshipbetweenpressureandtemperature.這里就存在著一個壓強與溫度的關系Whenthepressureofasubstanceisincreaseditstemperaturewillalsoincreas

6、e.當物體所受的壓強升高，它的溫度將隨之升高。Thepressureincreasessubstantiallyastherefrigeranttravelsthroughthecompressor.制冷劑通過壓縮機時，壓強急劇升高。Thelowpressuresideofthecircuitwouldtypicallybeunderthepressureof2bar;thehighpressurewouldtypicallybeunderthepressureof15bar.循環環路中的低壓端正常壓強為2巴，高壓端的正常壓強為15巴。Ariseof13bar!一下增加了13巴！Thislar

7、geincreaseinpressurealsoresultsinalargeincreaseintemperature.這一壓強的劇增同樣引起了溫度的驟升這一壓強的劇增同樣引起了溫度的大幅上升Thetemperatureoftherefrigerantenteringthecompressorwouldbe10-20Candthetemperatureoftherefrigerantexitingthecompressorwouldbeintheregionof90C!制冷劑進入壓縮機時溫度大概為10-20C，離開時溫度則會變為90C左右！Thishighpressurehightemper

8、aturegasthentravelsonwardstothecondenseralargeheatexchangerusuallylocatedinfrontoftheengineradiator.！這一高壓高溫氣體接著向冷凝器轉移。冷凝器是一個大的換熱器，通常位于引擎散熱器的前端。Iftwosubstancesofdifferingtemperaturesareplacedtogether,heatwilltravelfromthehottersubstancetothecoolersubstanceuntilbothsubstancesreachanequaltemperature.如果

9、不同溫度的兩種物質被放置在一起，熱量將會從較熱的物體向較冷的物體轉移，直到兩者溫度相等相當。Asthetermheatexchangersuggests,heatisexchangedfromthehotterbodytothecoolerbody.正如換熱器其名，熱量從較熱物體轉移交換到較冷物體上。Inthiscasethehotterbodyistherefrigerantgasandthecoolerbodycomprisesthefinsofthecondenser.這一情況中，較熱物體是氣態制冷劑，較冷物體包括冷凝器的那些散熱片。Astheheatistransferredtothe

10、finsofthecondenser,coolingairflowsoverthem.當熱量被轉移到散熱片上時，冷空氣從上層經過。Againaheatexchangeprocessoccursallowingtheheatfromthefinstotransferintothecoolerairtravellingpasttheminto,usually,theenginecompartment.這樣，又一次熱交換過程發生，散熱片上的熱量轉移至上空經過的冷空氣中，這些冷空氣通常是去往引擎室的。Astheheatisremovedfromtherefrigerantitstartstoconde

11、nse.由于制冷劑中的熱量被去除當熱量從制冷劑中剔除，制冷劑開始液化。當制冷劑繼續穿過冷凝器時，它不斷液化Astherefrigerantcontinuesitsjourneythroughthecondenseritcontinuestocondenseand,ideally,therefrigerantwillturnfullyintoaliquidbythetimeitexitsthecondenser.理想狀態下正常情況下，當制冷劑離開冷凝器時，它會完全轉變為液態。Fromthecondenser,theliquidrefrigeranttravelsontothemodulator.

12、液態冷凝劑接著從冷凝器向調節器移動。Thislookslikeanextratubeweldedontothesideofthecondenser.調節器看起來像是焊接到冷凝器一端的條附加管道。Themodulatorperformsthreemainactions.One,itactsasafilter,filteringoutparticlesastheytravelaroundtheACsystem.它主要有三個功能：首先，它像是一個過濾器，顆粒在穿過AC系統時會被過濾出來。Second,itactsasadryer.第二個作用是，它像一個干燥器。Thedryerinthemodulat

13、orcontainsdesiccant(likethesilicagelyoufindinanewboxofshoes).調節器里的干燥器裝著干燥劑，貌似新鞋鞋盒中的硅膠。Thisdesiccantabsorbswater.Aswatergetsintothesystemthedryertriestoremoveit.干燥劑會吸收水分，所以當水分穿過系統時，干燥劑會將水分吸收掉。Thethirdfunctionofthemodulatorisareservoir.調節器的第三個功能是一個儲存器裝置。Bearinginmindthepressureandtemperatureoftherefri

14、gerantinsidetheACsystemregularlychanges,sodoestherefrigerantsvolume.AC系統中循環的制冷劑的壓強和溫在度是有規律變化的，制冷劑的劑量也是如此。Thisvaryingvolumeisaccommodatedbythereceiverdryer.變化的劑量儲存在接受者角色的干燥劑儲液干燥器中。Fromthemodulator,therefrigerantflowstowardsthethermalexpansionvalve.制冷劑從調節器中出來，流向熱膨脹閥。Thisisaselfregulatingvalvewhichcont

15、rolstheamountofrefrigerantabletopassintoanotherheatexchangerlocatedbytheheatermatrixcalledtheevaporator.這個閥是一個自動調節閥，控制可以通過的制冷劑劑量。Asliquidrefrigerantpassesthroughtheexpansionvalve,intothelowpressuresideofthecircuit,apressurereductionoccurs.Thispressurereductioncausestheliquidrefrigeranttobeontheverge

16、ofbecomingagasbutitisstillaliquidatthisspecificpoint.制冷劑通過后將流入另一個換熱器。這是由稱為蒸發器的加熱器矩陣所固定的一個換熱器。液態制冷劑通過膨脹閥，進入環路的低壓端時，壓強減小。壓強的減小使得液態制冷劑幾乎變成氣態，但在通過膨脹閥這一刻，它的狀態仍是液態。Ifyouincreasethepressureappliedtoagasyoueventuallyendupwithaliquid;如果你增大施加在氣體上的壓強，最終它會變成液態。inversely,ifyoureducethepressureappliedtoaliquidyou

17、willeventuallyendupwithagas.反過來，如果減小施加在液體上的壓強，它會變成氣態。Itisonlywhentheliquidtravelsintotheevaporatorthattheliquidevaporatesandbecomesagas.只有在液態制冷劑穿過蒸發器時，液體蒸發，變成氣態。Thisprocessoccursduetotherefrigerantabsorbingheatfromtheairbeingblownthroughtheevaporator.發生這一過程的原因是制冷劑從經過蒸發器的空氣中吸收了熱量。Theprocessofevaporat

18、ioncausesacoolingeffect.蒸發的過程產生了制冷效應。Thelargerthequantityofliquidtravellingintotheevaporator,themoreevaporationthatwilloccur,whichinturnwillleadtoahigherquantityofheatenergybeingabsorbedbytheprocess.經過蒸發器的液體量越多，就會發生越多的蒸發過程。其結果就是在這一蒸發過程中，被吸收的熱量也就越多。Asairisblownthroughthefinsoftheevaporator(andasstate

19、deviouslyhottravelstocold),theheatcarriedbytheairtransferstothecoldfinsandinturnisabsorbedbytherefrigerant.空氣被吹動經過蒸發器的散熱片空氣被鼓吹經過蒸發器的散熱片，（如前所說，是熱流向冷），空氣負載的熱量轉移到冷的散熱片上，反過來被制冷劑吸收。Astheairlosessomeofitsheat,theairthatcomesbackoutofthefinsoftheevaporatoriscoolandthatcooledairisthenventedintothepassengerc

20、ompartment.當空氣失去一定熱量時，蒸發器散熱片中出來的回流空氣是冷空氣，這股冷空氣接著會被排放到乘客區這股冷空氣接著會被釋放到乘客區。Nowthattherefrigeranthasabsorbedsomeoftheheatfromthepassengercompartment,ithasdoneitsjobintheevaporatorandoutittravelsoftheevaporatorinagaseousstate.制冷劑此時已經吸收了來自乘客區的一部分熱量，這意味著它在蒸發器中的任務已經完成。離開蒸發器后，它的狀態為時氣態。Therefrigeranttravelsbacktothecompressorleavingthelowpressuresideofthecircuitandthewholeprocessstartsagain.制冷劑重新回到壓縮機，然后離開循環的低壓端然后離開環路的低壓端，整個過程重新開始。Coolertemperaturesmeansthattwod