Thuto ea Mahlaseli a Mocheso Lienjineng tsa Mocheso o Phahameng
Mechini e nang le mocheso o phahameng—joalo ka lionto tsa indasteri, liboiler, liturbine tsa khase, lionto tsa samente, li-reactor tsa lik'hemik'hale le lienjine tsa jete—e sebetsa tlas'a maemo a mocheso o feteletseng a hlokang taolo e hlokolosi ea mocheso. Har'a mekhoa e meraro ea phetisetso ea mocheso (ho tsamaisa mocheso, ho tsamaisa mocheso, le mahlaseli), mahlaseli a mocheso hangata e ba karolo e ka sehloohong ha mocheso oa holim'a metsi o phahama haholo. Sengoloa sena se tšohla likhopolo tsa motheo tsa mahlaseli, mekhoa ea ho ithuta le ea ho lekanya, ho etsa mohlala, le litlamorao tsa tsona bakeng sa moralo le polokeho ea mechini e nang le mocheso o phahameng.
1. Ke hobane'ng ha mahlaseli a mocheso a le bohlokoa maemong a mocheso o phahameng?
Mahlasedi a mocheso ke phetiso ya matla ka sebopeho sa maqhubu a motlakase, haholo-holo ka har'a spectrum ea infrared, mochesong o sebetsang oa mechini ea indasteri. Ho fapana le ho tsamaisa le ho tsamaisa, tse hlokang seaplane (se tiileng kapa mokelikeli), mahlaseli a ka hlaha esita le ka vacuum. Mechineng ea mocheso o phahameng, monehelo oa mahlaseli a eketseha ka potlako hobane boholo ba ona bo latela molao oa matla a bone mabapi le mocheso o felletseng (Kelvin). Sena se bolela hore keketseho ea mocheso ho tloha ho 800 K ho isa ho 1000 K e ka eketsa phallo ea mahlaseli haholo, leha liparamente tse ling li lula li sa fetohe.
Tšusumetso e sebetsang e kholo: mahlaseli a mocheso a ama katleho ea mocheso, bophelo ba thepa, botsitso ba ts'ebetso, boleng ba sehlahisoa lits'ebetsong tsa mocheso (mohlala, ho futhumatsa thepa), hammoho le likarolo tsa polokeho tse kang kotsi ea mollo le ho pepesehela mocheso ho basebetsi kapa likarolo tse bonolo.
2. Motheo oa khopolo-taba: Molao oa Stefan–Boltzmann le ho ntša metsi
Bakeng sa bokaholimo bo loketseng ba "mmele o motsho" bo monyang le ho ntsha mahlaseli ka botlalo, ho ntšoa ha mahlaseli ka sebaka sa yuniti ho entsoe ke Molao oa Stefan-Boltzmann:
\[
q = \sigma T^4
\]
ka:
– \(q\) = phallo ea mahlaseli (W/m²)
– \(\sigma\) = Stefan–Boltzmann e sa fetoheng (≈ \(5{,}67 \makgetlo a 10^{-8}\) W/m²·K⁴)
– \(T\) = mocheso o feletseng oa bokaholimo (K)
Leha ho le jwalo, bokahodimo ba nnete ha se mebele e metsho. Ka hona, ho sebediswa emissivity (\(\varepsilon\)), e nang le boleng ba 0–1. Bakeng sa bokahodimo ba nnete:
\[
q = \varepsilon \sigma T^4
\]
Ho ntsha mosi ho angoa ke thepa, ho ba thata ha bokaholimo, ho ntsha mosi, ho kwahela le bolelele ba mahlaseli. Lienjineng tse nang le mocheso o phahameng, bokaholimo ba tšepe hangata bo feta ho ntsha mosi, e leng se ka eketsang ho ntsha mosi, ka hona se eketsa mahlaseli a tswang. Sena se ka ba molemo bakeng sa ho phodisa ho sa sebetseng, empa se kotsi haeba sepheo sa sistimi e le ho boloka mocheso ka hare ho kamore ea ho tuka kapa ontong.
3. Phapanyetsano ea mahlaseli pakeng tsa libaka: ntlha ea pono
Ha e le hantle, se bohlokoa ha se feela mahlaseli a ntšoang, empa ke mahlaseli a nete a fetang ho tloha holim'a metsi a mang ho ea ho a mang. Bongata bo itšetlehile ka:
– mocheso oa bokaholimo bo bong le bo bong,
- ho ntša metsi,
– jeometri le tataiso ea bokaholimo,
– le ntlha ya pono, e leng karoloana ya mahlaseli a tswang hodima bokahodimo bo bong e fihlang hodima bokahodimo bo bong.
Mohlala, ka phaposing ea ho besa ea turbine ea khase kapa ontong, mabota, setofo, le ntho e futhumatsang kaofela lia "bonana". Ntlha ea pono e thusa ho bala hore na mocheso o phallela maboteng haholo-holo, mojarong (thepa e futhumatsang), kapa o lahleha ka masoba.
4. Mahlaseli likhase tse chesang le likaroloana
Lienjeneng tse nang le mocheso o phahameng, sebaka se pakeng tsa bokaholimo hangata ha se moea o hloekileng, empa ke likhase tse tukang (CO₂, mouoane oa H₂O), mosi, kapa likaroloana tsa mosi. Likhase tse ling li na le thepa ea ho "ntsha le ho monya" mahlaseli mefuteng e itseng ea bolelele ba maqhubu. Ketsahalo ena e bohlokoa ho:
– liboiler le lionto tsa mollo,
– setjheso,
– kamore ea ho besa ea turbine ea khase,
– sethibela-mocheso o phahameng.
Dikaroloana, tse kang mosi le molora, di ka eketsa ho ntshuwa le ho monngwa ha mahlaseli, hangata di eketsa phetiso ya mocheso o kganyang maboteng. Ka hona, dithuto tsa mahlaseli dienjeneng tse nang le mocheso o phahameng di ke ke tsa nahana feela ka bokahodimo bo tiileng, empa di lokela ho nahana le ka sebaka se kenellang.
5. Mokhoa oa ho lekanya mahlaseli a mocheso
Lithuto tsa mahlaseli a mocheso li hloka tlhahisoleseling mabapi le mocheso, thepa ea bokaholimo le li-spectra tsa mahlaseli. Mekhoa e meng e tloaelehileng e kenyelletsa:
1. Pyrometer ea infrared (pyrometer ea IR)
E sebelisoa ho lekanya mocheso oa bokaholimo ntle le ho kopana. Bothata ke ho fumana hore na ho ntša metsi ho nepahetse; liphoso tsa ho ntša metsi ho ka lebisa liphosong tse kholo tsa mocheso.
2. Khamera ea mocheso (setšoantšo sa mocheso)
E thusa ho etsa 'mapa oa kabo ea mocheso le libaka tse chesang. E loketse ho hlahloba lionto, ho thibela mocheso, kapa likarolo tsa turbine. Leha ho le joalo, tlhaloso e ntse e itšetlehile ka ho ntša metsi le tšusumetso ea mahlaseli a bonaselitsoeng a tsoang tikolohong.
3. Sensor ea phallo ea mocheso / radiometer
E lekanya phallo ea mocheso e amoheloang ke sensor. E ka sebelisoa ho lekola mojaro oa mahlaseli likarolong tse itseng, joalo ka lithebe tsa mocheso kapa likheo.
4. Tlhahlobo ea spectrometry le khase
Bakeng sa mecha ea khase e tukang, tlhahlobo ea spectrum e thusa ho etsa mohlala oa monehelo oa CO₂ le H₂O mahlaseling, haholo-holo khatellong le mochesong o phahameng.
Litekanyo tsa masimo hangata li kopanya lisebelisoa tse 'maloa ho etsa hore liphetho li nepahale haholoanyane: mohlala, khamera ea mocheso bakeng sa limmapa, pyrometer bakeng sa netefatso ea lintlha, le sensor ea phallo bakeng sa netefatso ea phetisetso ea mocheso.
6. Ho etsa mohlala le ho etsisa: ho tloha dipalong tse bonolo ho isa ho CFD
Mekhoa ea ho ithuta mahlaseli a mocheso ka kakaretso e arotsoe ka:
- Mohlala o bonolo oa tlhahlobo
E loketse likhakanyo tsa pele, mohlala, ho bala tahlehelo ea mocheso e phatsimang ho tsoa holim'a phaephe ea mocheso kapa sekoahelo sa enjene. Mohlala ona o potlakile, empa hangata o hloka likhakanyo tsa ho ntša metsi khafetsa le jiometri e bonolo.
- Mokhoa oa lipalo oa phapanyetsano ea mahlaseli a holim'a metsi
Ho sebelisoa mekhoa ea view factor le radiosity ho bala phapanyetsano ea matla lipakeng tsa libaka tse koetsoeng, joalo ka lionto tse bōpehileng joaloka lebokose kapa cylindrical.
– CFD e nang le mohlala oa mahlaseli
Ditsamaisong tse rarahaneng tse kenyeletsang phallo ya kgase e tukang le dikarabelo tsa dikhemikhale, CFD e sebediswa hangata. Mehlala ya mahlaseli a kotsi jwalo ka P1, Discrete Ordinates (DO), kapa mehlala ya Monte Carlo e thusa ho sebetsana le mecha ya phatlalatso e kenyang letsoho. Le hoja e nepahetse haholoanyane, CFD e hloka tlhahisoleseding mabapi le thepa ya kgase le mahlaseli a dikarolwana mme e hloka boiteko bo eketsehileng ba ho bala.
Netefatso ke ea bohlokoa: liphetho tsa ketsiso li tlameha ho bapisoa le lintlha tse lekantsoeng ho netefatsa hore liparamente tse kang ho ntša metsi ka katleho, kabo ea mosili, kapa coefficient ea ho monya khase ha li khelohe.
7. Litlamorao tsa moralo: thepa, lipeiti, le ho kenya mocheso
Lithuto tsa mahlaseli a mocheso li na le tšusumetso e tobileng liqetong tsa moralo:
– Khetho ea thepa le meeli ea mocheso
Lisebelisoa tse kang li-superalloy, li-ceramics le metsoako lia sebelisoa hobane li hanela ho thekesela le ho oxidation mochesong o phahameng. Leha ho le joalo, meroalo ea mahlaseli a kotsi e ka baka maemo a phahameng a mocheso a ka bakang ho petsoha ha mocheso.
– Seaparo sa thibelo ea mocheso (TBC)
Li-TBC tse ka har'a liturbine tsa khase li fokotsa sekhahla sa phetisetso ea mocheso ho ea substrate ea tšepe. Ntle le ho ba le motlakase o tlase, ho ntšoa ha mokelikeli oa sekoahelo ho boetse ho susumetsa ho leka-lekana ha matla a mahlaseli.
– Ho thibela ho ruruha le ho thiba lesela
Liontong, lintho tse thibelang mocheso li fokotsa tahlehelo ea mocheso mohahong o ka ntle. Libaka tse thibelang mocheso hangata li na le mosi o mongata; sena se ka thusa ho futhumatseng mocheso o matla oa cha, sa ntlafatsa ho tšoana ha mocheso, empa se lokela ho leka-lekana le ho laola tahlehelo ea mocheso ka masoba.
– Tsamaiso ea “Sebaka se Chesang”
Kabo e sa lekanang ea mahlaseli a kotsi e ka baka libaka tse chesang maboteng kapa likarolong. Moralo oa jeometri, boemo ba ho chesa, le tšebeliso ea li-baffle/reflector ka linako tse ling li sebelisoa ho lekana mojaro oa mahlaseli.
8. Polokeho le botshepehi
Mahlasedi a mocheso le ona ke taba ea polokeho. Ho pepesehela mahlaseli a mangata ho ka baka kotsi ho basebetsi, ha senya likhoele/lisebelisoa, kapa ha baka ho senyeha ha mafura le litiiso. Ka hona, indasteri e sebelisa:
– sesireletsi sa mocheso (sesireletsi sa mocheso),
– sebaka se sireletsehileng le ho thibela ho ruruha,
– mekhoa ea tlhahlobo ea thermographic nako le nako,
– le sistimi ea ho notlela haeba mocheso o feteletseng o bonoa.
Ka lehlakoreng la botshepehi, mahlaseli a mangata a potlakisa oxidation, a ama thepa ea mechini, 'me a potlakisa mokhathala oa mocheso. Lithuto tsa mahlaseli a mocheso li thusa ho bolela esale pele bophelo ba likarolo le ho nts'etsapele kemiso ea tlhokomelo e thehiloeng maemong.
9. Kesimpulan
Mahlasedi a mocheso ke mokhoa o matla haholo oa phetisetso ea mocheso lienjeneng tse nang le mocheso o phahameng hobane o itšetlehile haholo ka mocheso (ho ea ho matla a bone). Ho utloisisa emissivity, view factor, le karolo ea likhase tse tukang le likaroloana li theha motheo oa lithuto tse nepahetseng. Litekanyo tse sebelisang li-pyrometer, lik'hamera tsa mocheso, le li-sensor tsa flux li tlatsana le mohlala oa tlhahlobo, radiosity, le CFD ho bolela esale pele meroalo ea mocheso le ho fokotsa moralo. Ka lithuto tsa mahlaseli a molumo, liindasteri li ka ntlafatsa katleho, tsa boloka polokeho, le ho lelefatsa bophelo ba likarolo tsa enjene tlas'a maemo a feteletseng a ts'ebetso.
Haeba o lakatsa, nka fetola sengoloa sena ho latela moelelo oa mochini o itseng (mohlala, turbine ea khase, boiler ea setsi sa motlakase sa mouoane, sebōpi sa ho qhibilihisa, kapa onto), se feletse ka mehlala e bonolo ea lipalo le lenane la libuka.
