Ndondomeko adiabatic ndi chiyani?

Kumanga kutentha injini, amene akhoza kugwira ntchito ndi ntchito kutentha, muyenera kulenga zinthu zina. Choyamba, injini kutentha ntchito mu mode ozungulira, kumene chiwerengero cha njira zotsatizana thermodynamic kulenga kuzungulira. The chifukwa cha mkombero mpweya unazunguliridwa mu yamphamvu atavala pisitoni makina, Kodi ntchito. Koma mkombero wina kwa mtanda makina pang'ono, tiyenera iterate mobwerezabwereza kwa nthawi yaitali. The ntchito okwana anachita pa nthawi anakonzeratu kwenikweni kugawidwa ndi nthawi amapereka mfundo ina yofunika - mphamvu.

Mu zaka za m'ma XIX, ndi injini kutentha oyambirira analengedwa. Iwo ntchito, koma amawononga ndalama kutentha opangidwa ndi kuyaka wa mafuta. Zinali ndiye kuti sayansi ongolankhula akufunsa, "Kodi ntchito mpweya mu injini kutentha? Momwe ntchito kwambiri ndi osachepera mafuta? "

Kuchita Kupenda ntchito mpweya , izo zinkayenera kuti atchule dongosolo lonse la matanthauzo limaphunzitsa. Kuchotsedwa determinations onse ndipo analenga kafukufuku m'dera lonse amatchedwa "Engineering yopezeka m'zinthu zachilengedwe." Mu yopezeka m'zinthu zachilengedwe, anavomerezedwa angapo a maganizo, si angasokoneze mfundo zazikulu. Zida thupi - mpweya ephemeral (osati alipo mu chikhalidwe) sipangakhalenso wothinikizidwa kuti ziro buku lake mamolekyulu sindikufuna kucheza. Mu chilengedwe unalipo mpweya weniweni, amene katundu bwino chimatanthauza osiyana mafuta abwino.

Kuona chitsanzo cha mphamvu ya madzimadzi ntchito, icho ena amanena malamulo yopezeka m'zinthu zachilengedwe, amene akufotokoza njira zofunika thermodynamic monga:

• isochoric ndondomeko - ndondomeko imene imagwiridwa popanda kusintha buku la madzimadzi ntchito. Zokwaniritsa isochoric ndondomeko mndime = const;
• isobaric ndondomeko - ndondomeko imene imagwiridwa popanda kusintha kachulukidwe mu madzimadzi ntchito. Zokwaniritsa isobaric ndondomeko, P = const;
• isothermal (isothermal) ndondomeko - ndondomeko imene imagwiridwa pokhalabe kutentha pa mlingo anakonzeratu. Zokwaniritsa isothermal ndondomeko, T = const;
• adiabatic ndondomeko (adiabatic, choncho amatchedwa masiku matenthedwe Engineering) - njira, anachita danga popanda nzeru kutentha chilengedwe. Zikhalidwe za ndondomeko adiabatic, Q = 0;
• polytropic ndondomeko - ndiyo njira zowombetsa mkota amene akufotokoza njira thermodynamic zonse tatchulazi, komanso mwayi ena onse kukwaniritsidwa mu yamphamvu ndi pisitoni makina.

Pa chilengedwe cha injini kutentha woyamba anafufuza mkombero imene kuti dzuwa apamwamba (koyefishienti wa ntchito). Sadi Carnot, kufufuza ya njira thermodynamic, pa akufunira anapita ku kakulidwe ka mkombero wake, dzina lake - ndi Carnot mkombero. Iwo sequentially anachita isothermal, ndiye adiabatic psinjika ndondomeko. Madzimadzi ntchito pambuyo kukhazikitsa njira awa ali malo a mphamvu mkati, koma mkombero siinamalizidwe, kotero madzimadzi ntchito ndi kukodzedwa ndi kukachita isothermal ndondomeko kukula. Amalize mkombero ndi kubwerera kwa woyamba ntchito magawo madzimadzi, adiabatic ndondomeko kuwonjezeka imagwiridwa.

Carnot anatsimikizira kuti dzuwa mu mkombero wake kufika pazipita, ndipo zimatengera yekha pa kutentha kwa isotherms awiri. The apamwamba kusiyana pakati pa iwo, dzuwa safanana apamwamba matenthedwe. Kuyesa kulenga kutentha injini ya Carnot mkombero ndipo analephera kuzipeza. Ndi mkombero abwino amene sakhoza anachita. Koma iye anasonyeza mfundo yaikulu ya lamulo lachiwiri yopezeka m'zinthu zachilengedwe, za ndikosatheka kutenga ntchito, wofanana ndi mtengo wa mphamvu matenthedwe. zingapo matanthauzo amene anakonza lamulo lachiwiri (malamulo) Lamulo yopezeka m'zinthu zachilengedwe, monga zomwe Rudolf Clausius anayambitsa mfundo mphamvu zosagwiritsika ntchito. Poti waukulu kafukufuku - mphamvu zosagwiritsika ntchito zikuchulukirachulukira, imbaenda matenthedwe "imfa".

Kupambana chofunika kwambiri chinali kumvetsa Clausius wa adiabatic njira kukhazikitsa wa madzimadzi ntchito kwa mphamvu zosagwiritsika ntchito sasintha. Choncho, ndondomeko adiabatic Clausius - ndi m = const. Apa S - ndi mphamvu zosagwiritsika ntchito, amene amapereka dzina lina ndondomeko ikuchitika popanda kupereka kapena kuchotsa kutentha, - ndondomeko isentropic. Asayansi akufufuza ngati mkombero kutentha injini, kulikonse kumene kunali kuwonjezeka mu mphamvu zosagwiritsika ntchito. Koma, mwatsoka, izi sakanatha kulenga. Choncho anadziŵa kuti injini kutentha sangathe analenga konse.

Koma si ofufuza onse akhala kukhazikitsidwa kotero bwino. Iwo anali kufunafuna m'zinthu leni kwa makina ikukhudzana. Chifukwa cha kusaka awo Nikolaus August Otto analenga mkombero kutentha wake injini, amene tsopano akuyendera injini kuthamanga petulo. Apa, ndondomeko anachita ndi psinjika adiabatic wa thupi ntchito ndi isochoric kutentha kotunga (mafuta kuyaka pa buku zonse), ndiye pali adiabatic kuwonjezeka (amagwira ntchito ndi sing'anga ntchito mu ndondomeko ya kuwonjezera mphamvu zake), ndipo isochoric kutentha kuchotsa. Woyamba injini mkati kuyaka wa Otto mkombero ntchito ngati mafuta mpweya flammable. Patapita izo kupangidwa carburetors kuti akhala benzovozdushnoy kulenga chisakanizo cha mpweya ndi nthuzi mafuta ndi kudyetsa kwa yamphamvu engine.

Mu Otto mkombero mafuta osakaniza ndi wothinikizidwa, kotero kuchuluka kwa psinjika a ochepa ake - mafuta osakaniza ali ndi vuto detonate (amaphulika pamene mavuto yovuta, ndiponso kutentha). Choncho, ntchito mu adiabatic ndondomeko psinjika ndi wotsika. Apa ife timathandiza mfundo ina: pa psinjika chiŵerengero - chiŵerengero cha okwana buku voliyumu psinjika.

Kupeza njira kuonjezera mafuta dzuwa mphamvu anapitiriza. Kuchuluka dzuwa m'zimene kuwonjezeka psinjika chiŵerengero. Rudolf Dizilo anayamba mkombero zake zomwe chakudya kutentha ikuchitika pa sanasiye kutiuza (mu ndondomeko isobaric). mkombero ake anali maziko injini ntchito dizilo (amatchedwanso dizilo). Mu mkombero osakaniza Dizilo mafuta si wothinikizidwa, ndi mpweya. Choncho, kunena kuti amagwira ntchitoyo mu ndondomeko adiabatic. Kutentha ndi kuthamanga pa mapeto a psinjika mkulu, kupyolera mu jekeseni nozzle mafuta ikuchitika. Iwo uli wosakanizika ndi mpweya otentha kupanga osakaniza kuyaka. Moto umenewo unyeketsa, ichi kumawonjezera mphamvu mkati mwa madzimadzi ntchito. gasi Komanso ndi kuwonjezeka adiabatic ali, chinagwira ntchito sitiroko.

Atanganidwa ndi Dizilo mkombero injini kutentha analephera ndipo Gustav Trinkler Kulengedwa ophatikizana mkombero Trinklera. Ndipo ntchito mu injini dizilo lero. Mu vuto la kutentha umaperekedwa ndi Trinklera isochore, ndiyeno isobars lapansi. Pokhapokha zimenezi ndondomeko adiabatic cha kukula kwa madzimadzi ntchito.

Ndi kufanizira ndi injini pisitoni kutentha ndi ntchito chopangira mphamvu. Koma ndondomeko yawo ya kuchotsa kutentha pa mapeto a zothandiza adiabatic kukula kwa mpweya imagwiridwa ndi isobars. Pa ndege, injini mafuta chopangira mphamvu, ndi ndondomeko turboprop adiabatic amapezeka kawiri pa psinjika ndi kukula.

Kulungamitsa mfundo zonse chachikulu ndondomeko adiabatic akhala akufuna mitunduyi Pamudzi. Ukuoneka kufunika zofunika, wotchedwa adiabatic index. Mtengo wake ndi mpweya diatomic (mpweya ndi asafe - ndi zazikulu diatomic mpweya pano mu mlengalenga) wofanana 1.4. Kuwerengetsa index adiabatic ntchito ali ndi makhalidwe awiri chidwi, ndicho isobaric ndi isochoric kutentha mphamvu madzimadzi ntchito. The chiŵerengero cha K = CP / CV - ndi adiabatic index.

Chifukwa ntchito ndi ndondomeko adiabatic mu m'zinthu ongolankhula a injini kutentha? Kwenikweni anachita ndondomeko polytropic, koma chifukwa chakuti mwangozi mtengo kwambiri, iwo alandirika kuganiza pakalibe kuwombola kutentha chilengedwe.

90% ya magetsi ndi kwaiye ndi zomera matenthedwe mphamvu. Mu monga madzimadzi ntchito ntchito mpweya wotentha. Chifukwa amapangidwa pamene otentha. Kuonjezera mphamvu ntchito nthunzi, ndi koopsa. Ndiye, kuthamanga koopsa nthunzi umaperekedwa kwa chopangira mphamvu ndi nthunzi. Komanso inadzachitika adiabatic kuwonjezeka ndondomeko nthunzi. Chopangira mphamvu chimakhazikika pakubwezeretsa, imafalikira kwa jenereta ya magetsi. Ndiyeno, amapanga magetsi kwa ogula. Nthunzi turbines ntchito pa Rankine mkombero. Choncho dzuwa unakambidwanso mogwirizana ndi kuwonjezeka kutentha ndi kuthamanga nthunzi.

Malinga kuchokera pamwamba, ndi ndondomeko adiabatic sizachilendo kupanga mphamvu mawotchi ndi magetsi.