Nkhani yokhudza Lamulo Lachiwiri la Thermodynamics
Machitidwe onse achilengedwe amachitika mbali imodzi yokha koma sangachitike mbali ina, yomwe nthawi zambiri imatchedwa machitidwe osasinthika. Mango ikatulutsidwa kuchokera ku tsinde lake ndikugwa pansi momasuka , siimapitanso mmwamba. Buku lomwe timalikankhira kenako nkuima silibwerera kwa ife. Ngati tikhudza chinthu chotentha kwambiri (chinthu chotentha) ndi chinthu chozizira kwambiri (chinthu chozizira), kutentha kumatuluka mwachibadwa kuchokera ku chinthu chotentha kwambiri kupita ku chinthu chotentha kwambiri. Sitiwona njira yosinthira, komwe kutentha kumayenda mwachibadwa kuchokera ku chinthu chozizira kupita ku chinthu chotentha. Ngati njira iyi ikachitika, ndiye kuti chinthu chozizira chimakhala chozizira kwambiri, pomwe chinthu chotentha chimakhala chotentha kwambiri. Koma kwenikweni, sizili choncho. Pali njira zambiri zosasinthika zomwe zimawoneka zosiyana, koma zonse zimaphatikizapo kusintha kwa mphamvu ndi kusamutsa mphamvu kuchokera ku chinthu chimodzi kupita ku china.
Mwachitsanzo, pali chivomerezi champhamvu chomwe chimapangitsa kuti nyumba zigwe (nyumba zikugwa chifukwa cha mphamvu zomwe zimayendetsedwa ndi mafunde a chivomerezi). Kodi mudawonapo gawo lililonse la nyumba yogwa likubwerera pamodzi ndikuyimirira ngati kale? Kapena, mwachitsanzo, galasi likugwa pansi ndikusweka... Kodi mudawonapo zidutswa zagalasi zomwe zidabalalika pansi zikubwerera pamodzi ndikupanga galasi lomwe ndi lathunthu monga kale? Sizinachitikepo... pali zitsanzo zina zambiri.
Untuk menjelaskan proses termodinamika yang terjadi hanya pada satu arah (proses ireversibel), para ilmuwan merumuskan hukum kedua termodinamika. Hukum kedua termodinamika menjelaskan proses apa saja yang bisa terjadi di alam semesta dan proses apa saja yang tidak bisa terjadi. Salah seorang ilmuwan yang bernama R. J. E. Clausius (1822‐1888) membuat sebuah pernyataan berikut :
Kutentha kumayenda kokha kuchoka pa chinthu chotentha kwambiri kupita ku chinthu chotentha kwambiri; kutentha sikudzasuntha kokha kuchoka pa chinthu chotentha kwambiri kupita ku chinthu chotentha kwambiri (Lamulo lachiwiri la thermodynamics - Clausius statement).
Mawu a Clausius ndi mawu apadera a lamulo lachiwiri la thermodynamics. Amatchedwa mawu apadera chifukwa amagwira ntchito pa njira imodzi yokha, yomwe ndi kusamutsa kutentha. Chifukwa mawu awa sakugwirizana ndi njira zina, tikufunika mawu ofunikira kwambiri. Kukula kwa mawu onse a lamulo lachiwiri la thermodynamics kunachokera pang'ono pa kafukufuku wa injini zotenthetsera. Chifukwa chake, tikambirana kaye za injini zotenthetsera.
INJINI YOTENTHA
Mphamvu zambiri zomwe timagwiritsa ntchito zimachokera ku mphamvu ya mankhwala yomwe ili mu mafuta, gasi, ndi malasha. Mphamvu ya mankhwala yomwe ili mu mafuta, gasi, kapena malasha singagwiritsidwe ntchito mwachindunji. Mafuta, gasi, kapena malasha ayenera kuyatsidwa kaye. Kawirikawiri, kuyatsa mafuta osungiramo zinthu zakale (mafuta, gasi, ndi malasha) kumabweretsa kutentha. Kutentha kungagwiritsidwe ntchito mwachindunji kuphika chakudya ndikutenthetsa chipinda. Kuti tisunthe china chake (mwachitsanzo, kusuntha galimoto), tiyenera kusintha kutentha kukhala mphamvu ya kinetic kapena mphamvu ya makina (mphamvu ya makina = mphamvu yamagetsi + mphamvu ya kinetic). Kusintha mphamvu ya makina kukhala kutentha ndi ntchito yosavuta kwambiri, koma kusintha kutentha kukhala mphamvu ya makina ndi kovuta. Yesani kukanda manja anu pamodzi… manja anu ndi otentha, eti? Tikakanda manja athu pamodzi (timagwira ntchito), mphamvu ya makina imasinthidwa kukhala kutentha. Njirayi ndi yosavuta kwambiri… Ngakhale kutentha kosatha kumatha kupangidwa pogwira ntchito. Koma njira yotsutsana nayo, yomwe ndi kugwiritsa ntchito kutentha kuti igwire ntchito, ndi yovuta.
Chipangizo chomwe chimagwiritsidwa ntchito pokonza kutentha kuti chigwire ntchito chinapangidwa mu 1700. Chipangizo chomwe chikukambidwa chinali injini ya nthunzi. Mainjini a nthunzi anayamba kugwiritsidwa ntchito popopera madzi kuchokera m'migodi ya malasha. Ndikofunikira kudziwa kuti kugwiritsa ntchito koyamba kwa mainjini a nthunzi kunachitika asayansi asanadziwe kuti kutentha kwenikweni ndi mphamvu yomwe imasamutsidwa chifukwa cha kusiyana kwa kutentha (lamulo loyamba la thermodynamics linali lisanapangidwe).
Kugwiritsa ntchito mainjini a nthunzi panthawiyo mwina kunali kochokera ku zomwe zinkachitika tsiku ndi tsiku zomwe zimasonyeza kuti nthunzi imatha kusuntha zinthu. Mainjini a nthunzi amaonedwa ngati mainjini otentha (injini yotentha = chipangizo chosinthira kutentha kukhala mphamvu yamakina). Masiku ano, mainjini a nthunzi amagwiritsidwa ntchito popanga mphamvu zamagetsi. Mainjini otentha amakono ndi mainjini oyaka mkati (injini zamagalimoto, injini za njinga zamoto, ndi zina zotero).
Lingaliro loyambira kugwiritsa ntchito injini yotenthetsera ndilakuti kutentha kungasinthidwe kukhala mphamvu yamakina pokhapokha ngati kwaloledwa kuyenda kuchokera kudera lotentha kwambiri kupita kudera lotentha pang'ono. Panthawiyi, kutentha kwina kumasinthidwa kukhala mphamvu yamakina (kutentha kwina kumagwiritsidwa ntchito kugwira ntchito), pomwe kutentha kwina kumakanidwa kupita kudera lotentha pang'ono. Njira yosinthira mphamvu ndi kusamutsa mphamvu mu injini yotenthetsera ikuwonetsedwa pachithunzichi.
Kutentha kwambiri (T)H) ndi kutentha kochepa (TL) amatchedwanso kutentha kwa injini. Kutentha komwe kumachokera pamalo otentha kwambiri kumapatsidwa chizindikiro QH, pomwe kutentha komwe kumatulutsidwa pamalo otentha pang'ono kumapatsidwa chizindikiro QL. Pamene ikuyenda kuchokera pamalo otentha kwambiri kupita kumalo otentha pang'ono, Q inaH mphamvu ya makina (yomwe imagwiritsidwa ntchito pogwira ntchito), ina imatulutsidwa ngati QLNdipotu tikukhulupirira kuti Q yonseH ingasinthidwe kukhala W, koma zomwe zimachitika tsiku ndi tsiku zimasonyeza kuti izi sizingatheke. Nthawi zonse kutentha kumatayika. Chifukwa chake, kutengera kusunga mphamvu, zitha kutsimikizika kuti QH = W + QL.
Tsopano tiyeni tiwone injini yotenthetsera yomwe imagwiritsidwa ntchito kwambiri kusintha kutentha kukhala mphamvu yamakina. Ndikofunikira kudziwa kuti tikungoganizira za injini zotenthetsera zomwe zimagwira ntchito mosalekeza. Kuti ntchito izichitika mosalekeza, kutentha kuyenera kuyenda mosalekeza kuchokera kudera lotentha kwambiri kupita kudera lotentha pang'ono. Ngati kutentha kumayenda kamodzi kokha, ntchito yomwe injini yotenthetsera imagwiranso ntchito kamodzi kokha (mphamvu yamakina yomwe imapangidwira idzakhala yochepa kwambiri). Chifukwa chake, injini yotenthetsera singagwiritsidwe ntchito bwino. Injini yotenthetsera ingagwiritsidwe ntchito bwino ngati ikugwira ntchito mosalekeza. Mwanjira ina, mphamvu yamakina yomwe injini yotenthetsera imapanga ndi yokwanira kugwiritsidwa ntchito kusuntha china chake.
Injini ya nthunzi
Mainjini a nthunzi amagwiritsa ntchito nthunzi ya madzi ngati njira yosamutsira kutentha. Nthunzi imatchedwa chinthu chogwira ntchito cha injini ya nthunzi. Pali mitundu iwiri ya mainjini a nthunzi: mainjini a nthunzi obwerezabwereza ndi mainjini a nthunzi ya turbine (ma turbine a nthunzi). Mapangidwe awo amasiyana pang'ono, koma mitundu yonse iwiri imafanana: imagwiritsa ntchito nthunzi yotenthedwa ndi mafuta, gasi, malasha, kapena mphamvu ya nyukiliya.
Injini ya nthunzi yobwerezabwereza
Madzi omwe ali mu chidebe nthawi zambiri amatenthedwa ndi mphamvu yapamwamba. Chifukwa chakuti amatenthedwa ndi mphamvu yapamwamba, kuwira kumachitika ndi kutentha kwakukulu. Kutentha kumagwirizana mwachindunji ndi mphamvu. Kutentha kwa nthunzi kukakhala kwakukulu, mphamvu ya nthunzi imakulanso. Nthunzi yotentha kwambiri kapena yothamanga kwambiri imadutsa mu valavu yolowera ndikufalikira motsutsana ndi pisitoni. Pamene ikukula, nthunzi imakankhira pisitoni, zomwe zimapangitsa kuti isunthire kumanja.
Kutentha kwina mu nthunzi kumasanduka mphamvu ya kinetic. Pistoni ikasuntha kupita kumanja, gudumu lolumikizidwa ndi pistoni limazungulira (1). Pambuyo pozungulira theka, gudumu limakankhira pistoni kubwerera kumalo ake oyambirira (2). Pistoni ikasuntha kupita kumanzere, valavu yolowera imatseka yokha, pomwe valavu yotulutsa mpweya imatseguka yokha. Nthunzi imapindidwa ndi condenser, n’kusanduka mame. Kenako, madzi omwe ali mu condenser amapopedwanso m’chidebe kuti aphikidwenso. Ndi zina zotero… Chifukwa chakuti njirayi imachitika mobwerezabwereza, pistoni imasuntha kupita kumanja ndi kumanzere mosalekeza. Chifukwa pistoni imasuntha kupita kumanja ndi kumanzere mosalekeza, gudumu limazunguliranso mosalekeza. Kuzungulira kwa gudumu nthawi zambiri kumagwiritsidwa ntchito kusuntha china chake.
Turbine ya nthunzi
Mfundo yogwirira ntchito ya turbine ya nthunzi ndi yofanana ndi ya injini ya nthunzi yobwerezabwereza. Kusiyana kwake ndikuti injini ya nthunzi yobwerezabwereza imagwiritsa ntchito pisitoni, pomwe turbine ya nthunzi imagwiritsa ntchito turbine. Mu injini ya nthunzi yobwerezabwereza, kutentha kumasinthidwa kaye kukhala mphamvu ya kinetic yosinthira ya pisitoni. Pambuyo pake, mphamvu ya kinetic yosinthira ya pisitoni imasinthidwa kukhala mphamvu ya kinetic yozungulira ya gudumu lozungulira. Mu turbine ya nthunzi, kutentha kumasinthidwa mwachindunji kukhala mphamvu ya kinetic yozungulira ya turbine. Turbine imatha kuzungulira chifukwa cha kusiyana kwa kuthamanga. Kutentha kwa nthunzi pamwamba pa tsamba ndi kwakukulu kwambiri kuposa kutentha kwa nthunzi pansi pa tsamba. Tsamba ndi mbale yopyapyala yomwe ili pakati pa turbine. Kutentha kumafanana mwachindunji ndi kuthamanga. Chifukwa kutentha kwa nthunzi pamwamba pa tsamba ndi kokwera kuposa kutentha kwa nthunzi pansi pa tsamba, kuthamanga kwa nthunzi pamwamba pa tsamba ndi kwakukulu kuposa kuthamanga pansi pa tsamba. Kusiyana kwa kuthamanga kumeneku kumapangitsa nthunzi kukankhira tsamba pansi, zomwe zimapangitsa kuti turbine izungulire. Malangizo a kuzungulira kwa turbine akuwonetsedwa pachithunzichi.
Ndikofunikira kudziwa kuti mfundo yogwirira ntchito ya injini ya nthunzi imachokera pa chithunzi chotumizira mphamvu chomwe chafotokozedwa pamwambapa. Pankhaniyi, mphamvu yamakina ingapangidwe mwa kulola kutentha kutuluka kuchokera ku chinthu kapena malo okhala ndi kutentha kwakukulu kupita ku chinthu kapena malo okhala ndi kutentha kochepa. Chifukwa chake, kusiyana kwa kutentha ndikofunikira mu injini ya nthunzi.
Ngati muyang'ana momwe injini ya nthunzi yobwerezabwereza imagwirira ntchito, mudzazindikira kuti pisitoni ikhoza kusunthabe kumanzere ndi kumanja ngakhale kuti palibe kusiyana kwa kutentha (palibe condenser kapena pampu). Pisitoni imatha kusuntha kumanja chifukwa cha kufalikira kwa nthunzi yotentha kwambiri kapena yopanikizika kwambiri. Pankhaniyi, kutentha kwina mu nthunzi kumasanduka mphamvu ya kinetic yosinthika ya pisitoni. Mphamvu ya kinetic yosinthika iyi ya pisitoni imasanduka mphamvu ya kinetic yozungulira ya gudumu lozungulira. Pambuyo pomaliza kuzungulira theka, gudumu limakankhira pisitoni kumanzere. Gudumu likakankhira pisitoni kumanzere, mphamvu ya kinetic yozungulira ya gudumu imasandukanso mphamvu ya kinetic yosinthika ya pisitoni. Pisitoni ikasuntha kumanzere, imakankhira nthunzi mu silinda. Nthawi yomweyo, valavu yotulutsa mpweya imatsegulidwa.
Motero, nthunzi yomwe ikukankhidwa ndi pistoni idzakankhira mnzake pansi pa valavu yotulutsa mpweya. Tsopano, ngati kutentha kwa nthunzi pansi pa valavu yotulutsa mpweya kuli kofanana ndi kutentha kwa nthunzi yomwe ikukankhidwa ndi pistoni, ndiye kuti mphamvu yonse ya kinetic ya pistoni idzasinthidwa kukhala mphamvu yamkati ya nthunzi. Mphamvu yamkati imafanana ndi kutentha. Ngati mphamvu yamkati ya nthunzi ikuwonjezeka, kutentha kwa nthunzi kumawonjezeka. Kutentha kumafanana ndi kuthamanga. Ngati kutentha kwa nthunzi kukuwonjezeka, kuthamanga kwa nthunzi kumawonjezekanso. Motero, kuthamanga kwa nthunzi yomwe imatulutsidwa kudzera mu valavu yotulutsa mpweya kumafanana ndi kuthamanga kwa nthunzi yomwe imalowa kudzera mu valavu yolowera. Pistoni idzapitiriza kusuntha kumanja ndi kumanzere mosalekeza koma sipadzakhala mphamvu yonse ya kinetic yomwe ingagwiritsidwe ntchito (palibe ntchito yonse yopangidwa). Chifukwa chake mphamvu ya kinetic yomwe pistoni imalandira panthawi yokulitsa (pistoni imasunthira kumanja) idzabwezedwa ku nthunzi panthawi yokakamiza (pistoni imasunthira kumanzere).
Zatsimikizika kuti kusiyana kwa kutentha mu injini ya nthunzi ndikofunikirabe. Kusiyana kwa kutentha kumeneku mu injini ya nthunzi kungapezeke pogwiritsa ntchito condenser. Pamene kutentha ndi kupanikizika kwa nthunzi pansi pa valavu yotulutsa mpweya kuli kotsika kwambiri kuposa kutentha ndi kukakamiza kwa nthunzi mu silinda, ndiye kuti pistoni ikabwerera kumanzere, kukakamiza komwe pistoni imagwiritsa ntchito pa nthunzi kumakhala kochepa kwambiri kuposa kukakamiza komwe nthunzi imagwiritsa ntchito pa pistoni ikasuntha kupita kumanja. Mwanjira ina, kuchuluka kwa ntchito yomwe pistoni imagwira pa nthunzi kumakhala kochepa kwambiri kuposa kuchuluka kwa ntchito yomwe nthunzi imagwira pa pistoni. Chifukwa chake gawo laling'ono chabe la mphamvu ya kinetic ya pistoni imabwezeretsedwa ku nthunzi. Chifukwa chake, padzakhala mphamvu yonse ya kinetic kapena ntchito yonse yopangidwa. Mphamvu yonse ya kinetic iyi imagwiritsidwa ntchito kusuntha china chake.
Injini Yoyaka Yamkati
Injini za njinga zamoto ndi zamagalimoto ndi zitsanzo za injini zoyatsira mkati. Zimatchedwa injini zoyatsira mkati chifukwa njira yoyatsira imachitika mkati mwa silinda yotsekedwa. Injini zoyatsira mkati ndi zotsatira za kupanga lingaliro la kupsinjika ndi kukulitsa kwa adiabatic, komwe kwafotokozedwa mu lamulo loyamba la thermodynamics.
Tingoganizira za injini zoyatsira moto zomwe zimagwiritsa ntchito mafuta ndi dizilo ngati mafuta okha. Mafuta ndi dizilo ndi zinthu zopangidwa ndi mafuta, motero zimakhala ndi mphamvu ya mankhwala. Mphamvu ya mankhwala mu mafuta ndi dizilo imasinthidwa kukhala kutentha kudzera mu njira yoyatsira moto. Kutentha komwe kumapangidwa kudzera mu kuyatsa moto kumasinthidwa kukhala mphamvu ya makina. Mphamvu ya makina iyi ndi yomwe imalola njinga yamoto kapena galimoto kuyenda. Kuzungulira kwa injini ya mafuta kumatchedwa Otto cycle, pomwe kuzungulira kwa injini ya dizilo kumatchedwa dizilo cycle. Kuzungulira ndi njira yosinthika ya thermodynamic. Choyamba tiyeni tikambirane za Otto cycle.
Otto njinga
Iyi ndi chithunzi cha injini yoyaka moto yamkati yokhala ndi ma stroke anayi. Mpweya wosakaniza ndi nthunzi ya petulo umatuluka kuchokera ku carburetor kupita ku silinda pamene pistoni ikutsika pansi (kutsika kwa intake). Kusakaniza kwa mpweya ndi nthunzi ya petulo mu silinda kumakanikizidwa adiabatic pamene pistoni ikukwera mmwamba (kutsika kwa compression). Chifukwa chakuti imakanikizidwa adiabatic, kutentha ndi kupanikizika kwa chisakanizo kumawonjezeka. Nthawi yomweyo, spark plug imayatsa chisakanizocho, ndikuchiyatsa. Pamene chikuyaka, kutentha ndi kupanikizika kwa mpweya kumawonjezeka. Mpweya wotentha kwambiri, wopanikizika kwambiri umafalikira motsutsana ndi pistoni, ndikuchikankhira pansi (kutsika kwa expansion). Mpweya woyaka umatulutsidwa kudzera mu valavu yotulutsa mpweya ndikulunjika ku chitoliro chotulutsa mpweya (kutsika kwa intake). Vavu yolowetsa mpweya imatsegulidwanso, ndipo ma stroke anayi amabwerezedwanso.
Ndikofunika kudziwa kuti cholinga cha adiabatic compression stroke ndikuwonjezera kutentha ndi kukakamiza kwa nthunzi ya mpweya ndi mafuta. Kuyaka pamphamvu kwambiri kumabweretsa kutentha kwambiri ndi kukakamiza. Chifukwa chake, mphamvu ya thireyi (F = PA) yomwe imapangidwa panthawi yokulitsa mphamvu ndi yayikulu kwambiri. Izi zimapangitsa kuti injini ya njinga yamoto kapena galimoto ikhale yamphamvu kwambiri. Ngakhale popanda kukakamiza, nthunzi ya mpweya ndi mafuta imatha kuyaka pamene spark plug ipanga thireyi. Komabe, kutentha ndi kukakamiza kwa mpweya woyaka sikokwera kwambiri, kotero mphamvu ya thireyi nayonso ndi yaying'ono. Zotsatira zake, injini imakhala yochepa mphamvu.
Njira yosinthira mphamvu ndi kusamutsa mphamvu mu injini yoyaka yamkati ya ma stroke anayi ingathe kufotokozedwa motere: Pa nthawi yoyaka, mphamvu ya mankhwala yomwe imapezeka mu petulo ndi mphamvu yomwe ili mumlengalenga imasanduka kutentha. Kutentha kwina kumasanduka mphamvu yamakina mu ndodo ya pistoni ndi crankshaft, pomwe kwina kumatulutsidwa kudzera mu chitoliro chotulutsa utsi. Mphamvu zambiri zamakina zomwe zili mu ndodo ya pistoni ndi crankshaft zimasanduka mphamvu yamakina mugalimoto (kusuntha galimoto), pomwe gawo laling'ono limasanduka kutentha. Kutentha kumapangidwa ndi kukangana.
Kukula ndi kupsinjika kwa adiabatic mu Otto cycle kungawonetsedwe ndi chithunzi chomwe chili pansipa. Chithunzichi chikuwonetsa chitsanzo chabwino cha njira za thermodynamic zomwe zimachitika mu injini yoyaka yamkati yoyendetsedwa ndi mafuta.
Mpweya wosakaniza ndi nthunzi ya petulo umalowa mu silinda (a). Mpweya wosakaniza ndi nthunzi ya petulo umakanikizidwa motsatira njira ya adiabatic (a-b). Dziwani kuti kuchuluka kwa silinda kumachepa. Kusakaniza kwa mpweya ndi nthunzi ya petulo kumatenthedwa pa voliyumu yosasinthasintha - chosakanizacho chimatenthedwa (b-c). Mpweya wotentha umadutsa mu adiabatic expansion (c-d). Kuzizira pa voliyumu yosasinthasintha - mpweya wotentha umatulutsidwa mu chitoliro chotulutsa utsi ndipo chisakanizo chatsopano cha mpweya + nthunzi ya petulo chimalowa mu silinda (d-a).
Mpweya wosakaniza ndi nthunzi ya petulo umalowa mu silinda (a). Mpweya wosakaniza ndi nthunzi ya petulo umakanikizidwa motsatira njira ya adiabatic (a-b). Dziwani kuti kuchuluka kwa silinda kumachepa. Kusakaniza kwa mpweya ndi nthunzi ya petulo kumatenthedwa pa voliyumu yosasinthasintha - chosakanizacho chimatenthedwa (b-c). Mpweya wotentha umadutsa mu adiabatic expansion (c-d). Kuzizira pa voliyumu yosasinthasintha - mpweya wotentha umatulutsidwa mu chitoliro chotulutsa utsi ndipo chisakanizo chatsopano cha mpweya + nthunzi ya petulo chimalowa mu silinda (d-a).
Ulendo wa Dizilo
Mfundo yogwirira ntchito ya injini ya dizilo ndi yofanana ndi ya injini ya petulo. Kusiyana kwake kuli mu gawo loyamba la kukanikiza kwa adiabatic (kukanikiza kwa adiabatic = kukanikiza komwe kumachitika mwachangu kwambiri kotero kuti kutentha kulibe nthawi yolowera kapena kutuluka mu dongosolo. Pankhaniyi dongosololi ndi silinda). Mu injini ya petulo, chomwe chimakanizidwa ndi chisakanizo cha mpweya ndi nthunzi ya petulo, mu injini ya dizilo mpweya wokha ndi womwe umakanizidwa. Kukanikiza kwa adiabatic kumapangitsa kutentha ndi kukanikiza kwa mpweya kukwera. Kenako, injector, yomwe imadziwikanso kuti injector, imapopera dizilo. Chifukwa kutentha ndi kukanikiza kwa mpweya kumakhala kokwera kale, dizilo ikapopera mu silinda, dizilo imayaka nthawi yomweyo. Palibe chifukwa choyika spark plug. Onani kuchuluka kwa kukanikiza komwe kwawonetsedwa pachithunzichi pansipa. Yerekezerani ndi kuchuluka kwa kukanikiza komwe kwawonetsedwa pachithunzi cha Otto cycle.
Chithunzichi chikuwonetsa kayendedwe kabwino ka dizilo. Poyamba, mpweya umakanikizidwa ndi adiabatically (a-b), kenako umatenthedwa ndi mphamvu yosalekeza - injector imapopera dizilo ndipo kuyaka kumachitika (b-c), mpweya woyaka umadutsa mu adiabatic expansion (c-d), umazizira ndi mphamvu yosalekeza - mpweya woyaka umatuluka kudzera mu chitoliro chotulutsa utsi ndipo mpweya watsopano umalowa mu silinda (d-a).
Kutengera ndi kufotokozera pamwambapa, tinganene kuti injini iliyonse yotenthetsera imakhala ndi chinthu china chake chogwirira ntchito. Chinthu chogwirira ntchito cha injini ya nthunzi ndi madzi, chinthu chogwirira ntchito cha injini ya petulo ndi mpweya ndi nthunzi ya petulo, chinthu chogwirira ntchito cha injini ya dizilo ndi mpweya ndi dizilo. Chinthu chogwirira ntchito nthawi zambiri chimatenga kutentha pa kutentha kwakukulu (Q H ), chimagwira ntchito (W), kenako chimatulutsa kutentha kotsala pa kutentha kochepa (Q L ) . Chifukwa mphamvu zimasungidwa, ndiye Q H = W + Q L.
Kugwiritsa Ntchito Bwino kwa Injini Yotenthetsera
Kuchita bwino (e) kwa injini yotenthetsera ndi chiŵerengero pakati pa ntchito (W) yochitidwa ndi injini ndi momwe kutentha kumakhudzira kutentha kwambiri (Q H ). Mwa masamu, zitha kulembedwa motere:
W ndi phindu lomwe timalandira, pomwe QH ndi mtengo womwe timapeza pogula ndikuwotcha mafuta. Monga anthu omwe nthawi zonse amafuna kupeza phindu lalikulu kwambiri komanso ndalama zochepa zomwe tingathe kugwiritsa ntchito, tikukhulupirira kuti phindu lomwe timapeza (W) likugwirizana ndi mtengo womwe timapeza (QH). Kodi n'zotheka?
Kutengera ndi kusunga mphamvu, kutentha kolowera (Q H ) kuyenera kukhala kofanana ndi ntchito (W) yochitidwa + kutentha komwe kwatulutsidwa (Q L ).
Kuti muwonetse mphamvu ya injini yotenthetsera ngati peresenti, ingochulukitsani equation ya efficiency ndi 100%. Kutengera equation ya efficiency yomwe ili pamwambapa, kutentha kwambiri kukakanidwa (Q L ) ndi injini yotenthetsera, kumakhala kofooka. Tikufuna kwambiri kukhala ndi kutentha kochepa komwe kukana (Q L ) momwe tingathere. Komabe, heat input (Q H ) nthawi zambiri imapezeka poyatsa mafuta, malasha, gasi, ndi zina zotero (mafuta omwe timalipira).
Chifukwa chake, injini iliyonse yotenthetsera imapangidwa kuti ikhale yogwira ntchito bwino momwe ingathere. Ngakhale kuti timafuna phindu lalikulu kuchokera ku ndalama zochepa zomwe zingatheke, zoona zake n'zakuti injini za nthunzi nthawi zambiri zimakhala zogwira ntchito bwino ndi pafupifupi 40%, pomwe injini zoyatsira mkati zimakhala pafupifupi 50%. Izi zikutanthauza kuti theka la kutentha komwe kumapangidwa ndi mafuta oyaka kumawonongeka. Theka lokha limasandulika mphamvu yamakina.
Chitsanzo cha funso 1:
Injini yotenthetsera imayamwa ma Joules 3000 a kutentha (Q H ), imagwira ntchito (W) ndikutulutsa ma Joules 2500 a kutentha (Q L ). Kodi mphamvu ya injini yotenthetsera ndi yotani?
Zokambirana
Chitsanzo cha funso 2:
Injini yotenthetsera imayamwa ma Joules 3000 a kutentha (Q H ), imagwira ntchito (W) ndikutulutsa ma Joules 2000 a kutentha (Q L ). Kodi mphamvu ya injini yotenthetsera ndi yotani?
Zokambirana
Chitsanzo cha funso 3:
Injini yotenthetsera imayamwa ma Joules 3000 a kutentha (Q H ), imagwira ntchito (W) ndikutulutsa ma Joules 1500 a kutentha (Q L ). Kodi mphamvu ya injini yotenthetsera ndi yotani?
Zokambirana
