Kushandiswa kweRankine Cycle muSteam Power Plants
Zvivako zveMagetsi eSteam (PLTU) ndeimwe yematekinoroji anoshandiswa zvakanyanya kugadzira magetsi pasi rose. Musimboti wavo wekushanda unoshandisa simba rekupisa kushandura mvura kuita steam ine simba repamusoro uye tembiricha yepamusoro, wozoshandura simba resteam kuita simba remakanika kuburikidza neturbine, iyo inozoshandurwa kuita simba remagetsi nejenareta. Chinhu chikuru chekuchinja simba muPLTU iRankine Cycle, kutenderera kwethermodynamic kwakagadzirirwa masisitimu esimba resteam. Chinyorwa chino chinotaura nezvekushandiswa kweRankine Cycle muPLTU, zvikamu zvayo zvikuru, kutevedzana kwemaitiro, uye kuvandudzwa kwekushanda zvakanaka kwakajairika.
Pfungwa Yekutanga yeRankine Cycle
Rankine cycle idenderedzwa rethermodynamic rinotsanangura shanduko dzesimba mumvura inoshanda (kazhinji mvura/mvumbi) musystem yakavharwa. Iyi denderedzwa ndiyo hwaro hwekugadzirwa kwemagetsi anoshandisa marasha nekuti yakakodzera kugadzira magetsi uchishandisa zvikamu zvemvura uye zveutsi. Muchimiro chayo chakanaka, Rankine cycle ine maitiro mana makuru: kupomba mvura yekudya, kuidziisa muboiler kuti iite utsi, kuwedzera utsi muturbine kuti iite basa, uye kudzikamisa utsi mumvura mucondenser.
Kunyange zvazvo muchokwadi paine kurasikirwa kwesimba (kukweshana, kudonha kwepressure, kutamiswa kwekupisa kusina kukwana), modhi yeRankine Cycle ibasa rekuongorora mashandiro uye kuona nzvimbo dzinoshanda zvakanaka.
Zvikamu Zvikuru zveSitima yeMhepo muRankine Cycle
Kushandiswa kweRankine Cycle muchigadzirwa chemagetsi chinoshandiswa nemarasha kunosanganisira zvinhu zvakakosha zvakasiyana:
1. Pombi (Pombi yemvura yekudya)
Basa rayo nderekuwedzera kumanikidzwa kwemvura inonyungudika kubva pakumanikidzwa kwakaderera (condenser outlet) kusvika pakumanikidzwa kwakakwira kuitira kuti ikwanise kupinda mubhoyira. Nekuti kupomba mvura kunoda basa shoma kana tichienzanisa nekudzvanya gasi, basa repombi muRankine Cycle rinowanzova shoma pane basa returbine.
2. Boiler (Chinopa Simba reMvura)
Maboiler anoisa kupisa mumvura ine simba rakawanda kusvika yashanduka kuita utsi. Kupisa uku kunogadzirwa nemafuta anopisa (marasha, biomass, oiri, kana gasi) kana nezvimwe zvinhu, zvakaita sekupisa kunobva muchinhu chinobva muchinhu chinoshandisa simba renyukireya. Munzvimbo dzemagetsi dzinoshandiswa nemarasha, maboiler ane nzvimbo dzakasiyana-siyana: chinodziisa mvura (preheating), chinobvisa mvura (evaporator), uye chinodziisa mvura (superheating).
3. Turbine yemhepo inopfungaira
Maturbine anoshandura simba rekupisa nekumanikidzwa kwemhepo kuita basa remakanika kuburikidza nekuwedzera simba. Mugodhi weturbine wakabatana nejenareta kuti ugadzire magetsi. Maturbine anowanzova nematanho akawanda ekuwedzera simba rekuwedzera simba.
4. Chinotonhodza
Kondensa inotonhodza utsi hwemhepo inobuda muturbine, yoishandura kuita mvura zvakare. Nekugadzira kumanikidzwa kwakaderera kwemhepo inobuda (relative vacuum), kondensa inobatsira kuvandudza mashandiro eturbine uye kushanda zvakanaka kwayo. Kutonhodza kunowanzoitwa uchishandisa mvura yegungwa, mvura yerwizi, kana sisitimu yekutonhodza.
Kutevedzana kweMaitiro eRankine Cycle muSteam Power Plant
Kushandiswa kweRankine Cycle kunogona kutsanangurwa kuburikidza nematanho mana anotevera:
1) Maitiro ekupomba (1 → 2)
Kunyungudika kwemvura kubva mukondensateri kuri padanho rakaderera uye tembiricha yakaderera. Pombi inowedzera kumanikidzwa kwekushanda kwebhoyira. Panguva ino, tembiricha inokwira zvishoma, asi shanduko huru kuwedzera kwekumanikidzwa. Simba rinodiwa nepombi rinobva musimba remukati rejenareta, asi mupiro wayo mudiki kana tichienzanisa nesimba rinogadzirwa neturbine.
2) Maitiro ekuwedzera kupisa muBoiler (2 → 3)
Mvura ine simba rakawanda inopinda muboiler yodziiswa. Kutanga, mvura inodziiswa kusvika pakufashaira (kupisa kunonzwisisika), yozochinja kuita steam yakaguta (kupisa kwakavanzika), uye mumagadzirirwo mazhinji emagetsi anofambiswa nemarasha, steam inodziiswazve kuita steam inopisa zvikuru. Kupisa kwakanyanya kwakakosha nekuti steam yakaoma inopinda muturbine inoderedza njodzi yekukukurwa kwemashizha eturbine kubva mumadonhwe emvura.
Apa ndipo panoshandurwa simba remakemikari remafuta kuita simba rekupisa mumvura inoshanda. Kushanda zvakanaka kwekupisa, kutamiswa kwekupisa, uye dhizaini yebhoyira zvinokanganisa zvikuru mashandiro echigadzirwa.
3) Maitiro Ekuwedzera muTurbine (3 → 4)
Mhute ine simba guru inoyerera ichipinda muturbine yowedzera, ichideredza kumanikidzwa kwayo nekupisa uku ichigadzira mashandiro emakanika pashaft. Basa iri rinozofambisa jenareta. Mumamiriro ezvinhu akanaka, kuwedzera uku kunoonekwa se isentropic (constant entropy), asi mumamiriro ezvinhu chaiwo, kusachinjika kunoderedza kushanda kweturbine.
Hunhu hwemhepo inopfungaira pamucheto weturbine inyaya yakakosha. Kana mhepo inopfungaira yakanyanya kunyorova, madonhwe emvura anogona kurova mashizha eturbine okonzera ngura/kukurwa. Nokudaro, mafekitori emagetsi anowanzoedza kuchengetedza mwero wemhepo inopfungaira isina hunyoro pachiteshi cheturbine.
4) Maitiro Ekunyungudutsa MuCondenser (4 → 1)
Utsi hwemhepo inobuda muturbine hunopinda mucondenser uye hunoburitsa kupisa kunzvimbo inotonhorera, huchidzikamisa kuita mvura. Maitiro aya anoitika kana paine kumanikidzwa kwakaderera. Panyaya yesimba, kupisa kunorambwa mucondenser kunomiririra "kurasikirwa" kwekupisa uko kusingagone kushandurwa kuita basa, asi kuchiri kudikanwa kuti kutenderera kudzokororwe uye kuchengetedza kumanikidzwa kwakaderera kwemhepo inobuda, izvo zvinowedzera mashandiro eturbine.
Mvura yakasanganiswa inozodzokera kupombi kuti idzokorore kutenderera kwacho.
Zvikonzero Nei Rankine Cycle Ichishanda Pamiti Yemagetsi Emhepo
Kutenderera kweRankine kunoshanda zvikuru nekuti:
– Kushandisa mvura semvura inoshanda isingadhuri, yakachengeteka uye ine hunhu hwakanaka hwekupisa.
- Inoshandisa shanduko yekuchinja kwechikamu chemvura-utsi iyo inobvumira kunyudzwa kwekupisa kwakawanda.
– Inogona kugadziriswa nekuwedzera tembiricha nekumanikidzwa kwemhepo inopinda mu turbine, uye kuderedza kumanikidzwa kwe condenser.
- Inotsigira kushandiswa kwetekinoroji dzinovandudza mashandiro, dzakadai sekudziisa patsva uye kudziyisa patsva.
Kuvandudza Kushanda Nesimba: Kutenderera KweRankine Kwakagadziriswa
Muchokwadi, mafekitori emagetsi anoshandisa marasha haawanzo shandise nzira iri nyore yeRankine. Kugadziriswa kwakawanda kunowanzo shandiswa kuvandudza mashandiro uye kuchengetedza kuvimbika kwemidziyo:
1) Superheater uye Ultra-supercritical
Kukwidza tembiricha yemhepo isati yasvika turbine (superheating) kunowedzera kushanda zvakanaka kwekupisa nekuwedzera musiyano wesimba rinogona kuburitswa muturbine. Mamwe mafekitori emagetsi emazuva ano anoshandisa marasha anoshanda mumamiriro ezvinhu akaomarara kana kuti akaomarara, achishanda padanho repamusoro zvekuti hapana muganhu wemvura-utsi wakajeka mubhoyira. Iyi tekinoroji inogona kuwedzera kushanda zvakanaka asi inoda zvinhu zvinogona kutsungirira tembiricha/kumanikidzwa kwakanyanya.
2) Dziisazve
Mukudzokorora kupisa, utsi hwakakura zvishoma muturbine ine kumanikidzwa kwepamusoro hunodzoserwa kubhoyira kuti hudziyirwezve, hwozoiswa muturbine ine kumanikidzwa kwepakati/pasi. Chinangwa ndeche:
- kuwedzera basa rese re turbine,
– kuderedza hunyoro hwemhepo muzvikamu zvekupedzisira zve turbine,
- kuvandudza kushanda zvakanaka kwemuchina.
3) Kudziisa Mvura Inodzoreredza Kudya
Imwe steam inotorwa kubva mumatanho akati wandei eturbine (bleeding steam) kuti ipise feedwater isati yapinda muboiler kuburikidza ne feedwater heater. Nekukwidza tembiricha ye feedwater, zvinodiwa pakupisa kweboiler zvinodzikira uye kushanda zvakanaka kunowedzerwa. Sisitimu iyi inogona kushandisa heater yakavhurika (deaerator) kana heater yakavharika (closed heater).
4) Kugadzirisa Kondensa uye Sisitimu Yekutonhodza
Kuderedza kumanikidzwa kwe condenser (kuwedzera vacuum) kunowedzera kudonha kwe enthalpy mu turbine uye kuwedzera simba rinobuda. Zvisinei, izvi zvinoenderana nekukwanisa kwe system yekutonhodza kubvisa kupisa. Saka, kunaka kwe condenser, kuchena kwechubhu, uye tembiricha yemvura inotonhodza zvakakosha pakushanda zvakanaka.
Matambudziko Ekushanda Mukushandiswa KweRankine Cycle
Kunze kwezvakanakira, kushandiswa kweRankine Cycle muPLTU kunosangana nematambudziko:
- Kurasikirwa nesimba nekuda kwekukweshana kwemhepo, kubuda kwemvura, uye kutamiswa kwekupisa kusina kunaka.
– Hunhu hwemvura uye ngura: mvura yekudyisa inofanira kugadziriswa zvakasimba kudzivirira ngura uye ngura mumaboiler nematurbine.
– Hutsi hunobuda mumhepo nenzvimbo: muzvigadziko zvemagetsi zvinoshandisa marasha, kupisa kunogadzira CO₂, SOx, NOx, uye tunhu tudiki, saka michina yekudzora utsi inodiwa.
– Zvipingamupinyi zvezvinhu: kuwedzera kwekushisa nekumanikidzwa zvinoda zvinhu zvakakosha zvinodhura uye zvakaoma kuchengetedza.
Mhedziso
Kutenderera kweRankine ndiko kuri pakati pekushanda kwezviteshi zvemagetsi zvinoshandisa marasha (PLTU) nekuti kunobvumira kushandurwa kwesimba rekupisa kuita simba remakanika nemagetsi kuburikidza nemaitiro mana makuru: kupomba, kupisa, kuwedzera, uye kudziya kwemvura. Mukuita kwayo chaiko, kutenderera uku kunochinjwa nehunyanzvi hwakadai sema superheaters, reheaters, regenerative heating, uye condenser optimization kuti kuwedzere kushanda zvakanaka uye kuchengetedza kuvimbika kweturbine. Pasinei nematambudziko ane chekuita nekurasikirwa nesimba, mhando yemvura, uye kukanganisa kwezvakatipoteredza, kuiswa kweRankine cycle kunoramba kuri sarudzo huru yezviteshi zvemagetsi zvemhepo nekuda kwekuchinjika kwayo, kukura kwetekinoroji, uye kugona kuwedzera mashandiro sezvinodiwa.
Kana muchida, ndinogonawo kuwedzera dhayagiramu yekuyerera kwemaitiro kana tsananguro yeT–s (Temperature–Entropy) curve-based kuti kutenderera kuve kwakanyatsojeka uye kwehunyanzvi.
