SectionFour

Unit10:CondensationUnit11:EvaporationUnit12:MechanicalRefrigerationPrincipleUnit12:MechanicalRefrigerationPrincipleNewWords&ExpressionsTextNotestothe

TextExerciseNewWords&Expressions液體浮球閥containern.容器receivern.接受器，儲(chǔ)蓄罐liquidreceiver貯液桶throttlingdevice節(jié)流裝置regulatevt.調(diào)節(jié)，控制，管理valven.閥expansionvalve膨脹閥capillaryn.a.毛細(xì)管毛細(xì)作用的capillarytube毛細(xì)管floatvi.vt.n.（使）漂浮[流]浮體(子，球，筒)]liquidfloatvalveNewWords&Expressionsevaporatorn蒸發(fā)器suctionn.吸入[收，引]entrancen.入口

vacuumn.真空（度，狀態(tài)）stroken.沖程exertvt.施加exertpressureon對(duì)……施加壓力截獲，攔住trapvt.dischargevt.vi;n.排(放，流)出dischargevalve排氣閥dischargepressure排出壓passagen.通過(guò)NewWords&Expressionscondensern冷凝器.arrangementn.排列，布置，裝置submerge

vt.把…浸入；沉浸vi.淹沒(méi)；湮沒(méi)initiatevt.開(kāi)始，發(fā)動(dòng)condensevt.vi.（使）凝結(jié)approximatelyad.大約，近似地subsequenta.后來(lái)的，接著發(fā)生的evaporation

n.蒸發(fā)embracevt.包括(含，圍)Text

由液態(tài)到氣態(tài)再由氣態(tài)到液態(tài)的反復(fù)轉(zhuǎn)換是根據(jù)機(jī)械制冷的工作原理的基礎(chǔ)。這種氣體或液體被稱為制冷劑。這些氣體或液體，物質(zhì)冷卻效果的獲得就來(lái)源于這些介質(zhì)。液體制冷劑保留在一個(gè)容器里，這個(gè)容器叫做貯液桶。在一定的壓力作用下，液體制冷劑通過(guò)可以調(diào)節(jié)其流量的節(jié)流裝置，以達(dá)到預(yù)定的流量。節(jié)流機(jī)構(gòu)根據(jù)服役的類型在設(shè)計(jì)方面有所不同。其中包括熱力膨脹閥，一個(gè)毛細(xì)管和一個(gè)液體浮球節(jié)流閥。節(jié)流機(jī)構(gòu)的作用只是調(diào)節(jié)進(jìn)入蒸發(fā)器或冷卻盤管制冷劑的流量。Therepeatedtransformationofliquidtogasandgasbacktoitsliquidstateisthebasisonwhichmechanicalrefrigerationoperates.Thisgasorliquidisknownasrefrigerant,andisthemediumfromwhichthecoolingeffectonasubstanceisobtained.Liquidrefrigerantleavingacontainer,calledaliquidreceiver,underpressure,passesthroughathrottlingdevicethatcanregulateitsflowtoanydesiredamount.Throttlingdevicesvaryindesignaccordingtothetypeofservice,andincludetheexpansionvalve,acapillarytube,andaliquidfloatvalve.Thepurposeofthethrottlingdeviceissimplytoregulatetheamountofliquidallowedtopassthroughitonitswaytotheevaporatororcoolingcoil.1.Text

通過(guò)吸氣閥制冷劑從蒸發(fā)器被吸入壓縮機(jī)氣缸內(nèi)。制冷劑進(jìn)入壓縮機(jī)氣缸入口處，由于活塞在氣缸內(nèi)作上下運(yùn)動(dòng)，而產(chǎn)生真空狀態(tài)，制冷劑蒸氣進(jìn)入氣缸。液態(tài)制冷劑有特定的沸點(diǎn)，制冷機(jī)的類型不同并且任何液體的沸點(diǎn)隨施加于其上的壓力而變化。在氣缸吸入沖程過(guò)程中，由于壓縮機(jī)活塞的運(yùn)動(dòng)，引起儲(chǔ)液桶（高壓側(cè)）和蒸發(fā)器（低壓側(cè)）之間的壓差。

Fromtheevaporator,itisdrawnintoacompressorcylinderthroughasuctionvalve.Entranceoftherefrigerantintothecompressorcylinderiscausedbythevacuumcreatedbytheactionofthepistononitsdownwardorsuctionstroke.Therefrigerantentersthecylinderasagas.Refrigerantsintheirliquidstatehaveadefiniteboilingpoint,andtheboilingpointofanyliquidvarieswiththepressureexertedonit,differingwiththetypeofrefrigerant.Thepressurewithintheevaporatorisloweredbecauseoftheactionofthecompressorpistonduringitssuctionstroke,causingadifferentialinpressuresbetweenthereceiver(orhigh-pressureside)andtheevaporator(orlow-pressureside)ofthesystem.Text

其結(jié)果是液體制冷劑由儲(chǔ)液桶通過(guò)節(jié)流裝置進(jìn)入蒸發(fā)器。一進(jìn)入低壓區(qū)制冷劑的沸點(diǎn)就降低，而制冷劑從物質(zhì)吸收的熱量、將其溫度提高到新的沸點(diǎn)之上，取決于蒸發(fā)器的壓力，使其沸騰或蒸發(fā)。該沸點(diǎn)取決于蒸發(fā)氣的壓力，制冷時(shí)，液體制冷劑蒸發(fā)過(guò)程所吸收的熱量使溫度下降。Theresultisamovementoftheliquidrefrigerantfromthereceiverthroughthethrottlingdeviceintotheevaporator.2Uponenteringthelow-pressurearea,theboilingpointoftherefrigerantisreducedandtheheatabsorbedbytherefrigerantfromthesubstanceraisesitstemperatureabovethenewboilingpointwhichisgovernedbytheevaporatorpressure,causingistoboilorevaporate.Theheatabsorbedduringevaporationoftheliquidrefrigerantcausesthetemperaturetodropwithinthesubstancetobecooled.Text

進(jìn)入壓縮機(jī)，蒸氣制冷劑圍繞著這個(gè)系統(tǒng)過(guò)程開(kāi)始了。（吸氣、壓縮、排氣）當(dāng)活塞到達(dá)壓縮機(jī)沖程底部的極限時(shí)，活塞立即開(kāi)始向上運(yùn)動(dòng)，吸氣閥關(guān)閉，擋住氣缸內(nèi)氣體。當(dāng)活塞向上運(yùn)動(dòng)時(shí)，氣缸內(nèi)氣體被壓縮產(chǎn)生壓縮氣體，提高壓力，同時(shí)也提高了溫度的沸點(diǎn)。當(dāng)氣缸內(nèi)的壓力足夠增大時(shí)，壓縮機(jī)的吸氣閥被迫打開(kāi)（低壓蒸汽，就由吸氣室進(jìn)入氣缸）。通過(guò)排氣管(刪除)，蒸汽進(jìn)入最未端的冷凝器。這個(gè)冷凝器是由通過(guò)制冷劑蒸氣流動(dòng)的蛇形盤管排列而成，浸在冷卻水中或采用風(fēng)機(jī)加速空氣的流動(dòng)。（制冷劑蒸氣在管內(nèi)冷凝空氣在管外流過(guò)）空氣在風(fēng)機(jī)的作用下從管外流過(guò)。其結(jié)果氣體的溫度降到沸點(diǎn)以下，使制冷劑冷凝。Enteringthecompressor,therefrigerantinitsgaseousformisstartedonthethirdstepinitsjourneyaroundthesystem.3Uponreachingthebottomlimitsofitsstroke,thepistonimmediatelystartsupwardandthesuctionvalvecloses,trappingthegaswithinthecylinder.Asthepistonmovesupward,compressionofthegasoccurs,raisingthepressure,which,inturn,increasesitstemperatureandboilingpoint.Thedischargevalveofthecompressorisforcedopenwhenthepressurewithinthecylinderincreasessufficiently,allowingthepassageofthegasintothecondenseronitsfinalstage.Thecondenserconsistsofanarrangementofpipesthroughwhichthegasflows,submergedincomparativelycoldwater,orexposedtoaflowofairinitiatedbymeansofafan.Theresultisaloweringofthegastemperaturebelowtheboilingpoint,causingittocondense.Text

制冷劑作為液體離開(kāi)蒸發(fā)器，并進(jìn)入貯液桶，即初使位置。一種液體在高壓和接近室內(nèi)溫度下蒸發(fā)，為了把沸點(diǎn)降到冷卻的物質(zhì)溫度以下，它的壓力應(yīng)明顯地降低。通過(guò)蒸發(fā)器內(nèi)連續(xù)蒸發(fā)，這就使它轉(zhuǎn)換成氣體然后這些氣體再次被壓縮，并冷卻到重新壓縮的壓力的沸點(diǎn)溫度以下，再次轉(zhuǎn)變成液態(tài)并且儲(chǔ)存起來(lái)，待重新利用。Therefrigerantleavesthecondenserasaliquidandenterstheliquidreceiver,itsoriginallocation.Aliquidistakenathighpressureandapproximatelyroomtemperature.Itspressureisdecreasedconsiderablytoreducetheboilingpointbelowthetemperatureofthesubstancebeingcooled.Thiscausesitsconversiontoagasbysubsequentevaporationwithintheevaporator.Thegasisthenrecompressed,cooledtoatemperaturebelowtheboilingpointattherecompressedpressure,transformedagaintotheliquidphase,andstoredforre-useintheliquidreceiver.Text

包括壓縮機(jī)、冷凝器、儲(chǔ)液桶及相互連接的來(lái)回管道，被稱為高壓側(cè)，在儲(chǔ)液灌中保持的壓力稱排出壓力，或排放壓力。蒸發(fā)器與節(jié)流裝置相通的管路，以及從節(jié)流裝置到壓縮機(jī)的吸氣閥被稱為低壓側(cè)，這側(cè)所保持的壓力，被稱為吸入壓力。從制冷劑離開(kāi)節(jié)流裝置，進(jìn)入蒸發(fā)器時(shí)起直到它以液體的形式回到貯液桶。它已把每個(gè)狀態(tài)過(guò)程都進(jìn)行一遍。這就稱之為機(jī)械制冷循環(huán)。

Thatportionofthesystemembracingthecompressor,thecondenser,theliquidreceiverandthelinesleadingtoandfromeachoneisknownasthehigh-pressureside,andthepressuremaintainedwithinthissideiscalledtheheadordischargepressure.Theevaporator,andthelinesleadingtoitfromthethrottlingdeviceandfromittothecompressorsuctionvalve,iscalledthelow-pressureside.Thepressurewithinthissideisknownasthesuctionpressure.

Fromthetimetherefrigerantleavesthethrottlingdevicetoentertheevaporatoruntilitreturnsinitsliquidformtothereceiver,itwillhavecompletedeachphaseofitsactivityonce.4Thisisknownasamechanicalrefrigerationcycle.

NotestotheTextNotestotheText

1、Thepurposeofthethrottlingdeviceissimplytoregulatetheamountofliquidallowedtopassthroughitonitswaytotheevaporatororcoolingcoil.issimplytoregulate只是調(diào)節(jié)這是一個(gè)beto+inf.的結(jié)構(gòu)，不定式做表語(yǔ)。Thepurposeoftheexperimentistoknowthepropertiesofnaturalmagnets.實(shí)驗(yàn)的目的是了解天然磁石的性能。allowedtopassthroughit被允許經(jīng)過(guò)它的（過(guò)去分詞短語(yǔ)，做liquid的定語(yǔ)）onitswayto在它去……的途中onthe[one's]way在途中I'llbuysomeonmywayhome.在回家的途中我將買一些。Theyarestillontheway.他們?nèi)栽诼猛局?。He'sonthewaytosuccess.他正在走向成功的路上。NotestotheTextupon[on]+ing(剛)一……就……，在……時(shí)。例如：Uponarrivingatthestationthelocomotivestopped.機(jī)車一到達(dá)就停下來(lái)。Ironmayexpandalittleonheatingorcontractoncooling.鐵遇熱就稍有膨脹，遇冷就稍有收縮。which引入一個(gè)限制性定語(yǔ)從句，修飾boilingpoint。causingittoboilorevaporate使其沸騰或蒸發(fā)（現(xiàn)在分詞短語(yǔ)，做結(jié)果狀語(yǔ)）2、Uponenteringthelow-pressurearea,theboilingpointoftherefrigerantisreducedandtheheatabsorbedbytherefrigerantfromthesubstanceraisesitstemperatureabovethenewboilingpointwhichisgovernedbytheevaporatorpressure,causingittoboilorevaporate.

NotestotheTextenteringthecompressor進(jìn)入壓縮機(jī)（現(xiàn)在分詞短語(yǔ)，做時(shí)間狀語(yǔ)）這里，現(xiàn)在分詞entering與句子謂語(yǔ)動(dòng)詞的時(shí)間關(guān)系是分詞所表示的動(dòng)作一發(fā)生，謂語(yǔ)所表示的動(dòng)作立即接著發(fā)生。Hearingthenoise,theyimmediatelystoppedtalking.聽(tīng)見(jiàn)了這聲音他們立刻不說(shuō)話了。isstarted是start的被動(dòng)態(tài)。StartMonN使M開(kāi)始N3、Enteringthecompressor,therefrigerantinitsgaseousformisstartedonthethirdstepinitsjourneyaroundthesystem.NotestotheText從制冷劑離開(kāi)裝置進(jìn)入蒸發(fā)器直到它以液體形式回到貯液桶，它已把它的活動(dòng)的各個(gè)階段都完成了一遍。therefrigerantleavesthethrottlingdevicetoentertheevaporator是修飾time的限制性定語(yǔ)從句，省略了關(guān)系詞。4、Fromthetimetherefrigerantleavesthethrottingdevicetoentertheevaporatoruntilitreturnsinitsliquidformtotherece