Ucwaningo Lobunjiniyela Be-Thermodynamics Ngezinhlelo Zebhoyila Zezimboni
I-Pendahuluan
Ama-boiler ezimboni angenye yezingxenye zemishini ebaluleke kakhulu emikhakheni eyahlukene—kusukela ezitshalweni zamandla nezitshalo zamakhemikhali kuya ku-pulp nephepha, ngisho nasembonini yokudla neziphuzo. Umsebenzi wawo oyinhloko ukuguqula amandla amakhemikhali kusuka kuphethiloli (noma amandla kagesi kuma-boiler kagesi) abe amandla okushisa, bese ewadlulisela emanzini ukuze akhiqize umusi ngezingcindezi ezithile namazinga okushisa. Lo musi usetshenziselwa ukufudumeza inqubo, ukomisa, ukubulala amagciwane, noma njengoketshezi olusebenzayo lwe-turbine. Ukuze uhlelo lwe-boiler lusebenze ngokuphepha, ngokonga, nangokusebenza kahle, kudingeka ucwaningo lobunjiniyela be-thermodynamic, okuhlanganisa izilinganiso zamandla, ukusebenza kahle, ukulahlekelwa ukushisa, kanye nokuhlaziywa kokungaguquki.
Imiqondo Eyisisekelo Ye-Thermodynamics Kuma-Boilers
Ngokwe-thermodynamic, ama-boiler ngokuvamile ahlaziywa njengezinhlelo zokugeleza okuzinzile lapho inqwaba yamanzi angena khona, ithola ukushisa okuvela ekushiseni, bese iphuma njengomusi ogcwele noma umusi oshisayo kakhulu. Umthetho Wokuqala We-Thermodynamics wesistimu yokugeleza okuzinzile (isibalo samandla okugeleza okuzinzile) ungashiwo kalula:
\[
\dot{Q} – \dot{W} = \dot{m}(h_{out}-h_{in})
\]
Kuma-boiler, umsebenzi we-shaft (\(\dot{W}\)) uvame ukunganakwa ngoba i-boiler ayikhiqizi umsebenzi womshini ngqo. Amandla e-kinetic kanye ne-potential nawo mancane uma kuqhathaniswa noshintsho lwe-enthalpy, ngakho-ke i-equation esebenzayo iba:
\[
\dot{Q} \approx \dot{m}(h_{steam}-h_{fw})
\]
Yilapho i-enthalpy iba khona ipharamitha ebalulekile. Idatha yamanzi kanye ne-enthalpy yomphunga itholakala kumathebula omphunga noma kuma-Mollier diagrams (h–s). Amanzi okudla ngomfutho othile angaba ngamanzi angaphansi kokupholisa, kuyilapho umphumela ungaba umusi owomile ogcwele, umusi omanzi (oqukethe ikhwalithi yomphunga x), noma umusi oshisayo kakhulu.
Inqubo Yokushisa Amanzi Abe Yisiphuphu
Ngokwe-thermodynamic, ukufudumeza amanzi kubhoyila kuhamba ngezigaba eziningana:
1. Ukushisa kwamanzi okuphakelwayo (ukushisa okunengqondo)
Amanzi aphakanyiswa ekushiseni kusukela ekungeneni kuya ekushiseni kokugcwala lapho kucindezelwa ukusebenza. Amandla adingekayo alingana nomthamo wokushisa kanye nokwenyuka kwezinga lokushisa.
2. Ukuhwamuka (ushintsho lwesigaba / ukushisa okucashile)
Endaweni yokugcwala, ukwengezwa kokushisa kubangela ushintsho lwesigaba kusuka koketshezi kuya komusi. Kulesi sigaba, izinga lokushisa lihlala lingaguquguquki, kodwa i-enthalpy iyanda kakhulu ngenxa yokushisa okucashile kokuhwamuka.
3. Ukushisa kakhulu (uma kukhona i-superheater)
Umusi ogcwele uyashiswa ukuze kukhushulwe izinga lokushisa lawo libe ngaphezu kwezinga lokushisa lokugcwala ngokucindezela okufanayo. Ukushisa okuphezulu kwandisa i-enthalpy futhi kunciphisa umswakama womusi, okuzuzisa ukusetshenziswa kwe-turbine kanye nokusebenza kahle kwenqubo.
Emiklamo yesimanje yamabhoyila, ukubuyiselwa kokushisa kuvame ukuthuthukiswa ngezingxenye ezengeziwe ezifana nama-economizer (ama-feedwater heater), ama-air preheater (ama-combustion air heater), kanye nama-superheater. Ngayinye ihlose ukunciphisa ukulahlekelwa yizitaki nokwandisa ukusebenza kahle kokudlulisa ukushisa.
Ibhalansi Yamandla Nokusebenza Kahle Kwebhoyila
Ukusebenza kahle kwebhoyila ngokuvamile kuchazwa njengesilinganiso samandla awusizo amuncwa amanzi/umusi kumandla amakhemikhali kaphethiloli oshisiwe. Izindlela ezimbili ezidumile yilezi:
1. Indlela eqondile (indlela eqondile / indlela yokufaka-yokukhipha)
\[
\eta_{boiler}=\frac{\dot{m}_{steam}(h_{steam}-h_{fw})}{\dot{m}_{fuel}\times LHV}\times 100\%
\]
Nge-LHV (Inani Eliphansi Lokushisa) noma i-HHV (Inani Eliphezulu Lokushisa) kuye ngokuthi kusetshenziswe izinga elijwayelekile.
2. Indlela engaqondile (indlela yokulahlekelwa ukushisa)
Ukusebenza kahle kubalwa kusukela ekulahlekelweni kokushisa okuphelele okungu-100%, isibonelo:
– Ukulahleka kwegesi yomoya owomile
– Ukulahlekelwa ngenxa yomhwamuko wamanzi obangelwa ukusha kwe-hydrogen
– Ukulahlekelwa ngenxa kaphethiloli kanye nomswakama womoya
– Ukulahlekelwa okubangelwa yikhabhoni engashiswanga
– Ukulahlekelwa yimisebe kanye nokuguquguquka kwe-convection kusuka ebusweni bebhoyila
- Ukulahlekelwa yi-Blowdown
Izindlela ezingaqondile zivame ukusetshenziswa ekuhlolweni kwamandla ngoba zisiza ekuboneni imithombo eyinhloko yokungasebenzi kahle.
Ukulahlekelwa Okukhulu Kokushisa Ekusebenzeni Kwebhoyila
Ucwaningo oluhle lwe-thermodynamic alugcini ekubaleni okuphumayo-okufakwayo, kodwa futhi lubala ukulahlekelwa kwamandla okuyinhloko.
1. Ukulahleka kwenqwaba (ukulahlekelwa yitshimini)
Amagesi okukhipha umoya aphuma emazingeni okushisa aphezulu aphethe i-enthalpy enkulu. Imizamo yokunciphisa lokhu ingenziwa ngama-economizer nama-air preheater, kodwa kufanele kuqashelwe ukuqinisekisa ukuthi awadluli iphuzu lamazolo e-acid (ikakhulukazi kumafutha aqukethe i-sulfur) ukuze kuvinjelwe ukugqwala.
2. Ukuqhuma
Ukufuthwa kwamanzi kuyadingeka ukulawula ukugcwala kwezinto eziqinile ezincibilikisiwe (TDS) ebhoyileni. Kodwa-ke, ukususwa kwala manzi ashisayo kusho ukulahlekelwa yi-enthalpy. Uhlelo lokubuyisa ukushisa olufuthwa ngamanzi lungasebenzisa lokhu kushisa ukufudumeza amanzi okuhambisa amanzi noma amanzi okuzenzela.
3. Umoya omningi kanye nokusha okungaphelele
Umoya owengeziwe uyadingeka ukuze kushiswe kahle, kodwa umoya owengeziwe kakhulu wandisa isisindo segesi yomoya ongcolile, okwandisa ukulahleka kwenqwaba. Ngokuphambene nalokho, umoya onganele uholela ekwandeni kwe-CO2 kanye nophethiloli ongashiswanga—kokubili kuyingozi. Ukuthuthukiswa kufezwa ngokulawula igesi yomoya ongcolile i-O₂/CO2 kanye nokulungiswa kwesishisi.
4. Imisebe kanye nokuguquguquka kwezakhi zomkhathi kusuka phezulu
Ukufakwa kokushisa okungekuhle kwandisa ukulahlekelwa ukushisa emvelweni. Ukuthuthukiswa kokushisa okubangelwa ukushaqeka kanye nokufakwa kokushisa ngokuvamile kunomthelela oqondile ekusebenzeni kahle nasekuphepheni.
Ukuhlaziywa Kokuzivocavoca: Ukuhlola Ikhwalithi Yamandla
Ngaphezu kwamandla (uMthetho I), i-thermodynamics yobunjiniyela besimanje ivame ukusebenzisa ukuhlaziywa kokuzivocavoca ukuhlola "ikhwalithi" yamandla kanye nokungaguquki (uMthetho II). I-Exergy ichaza umsebenzi omkhulu ongatholakala lapho uhlelo lulethwa ezimweni zalo ezizungezile.
Kuma-boiler, ukuguquguquka okukhulu kwenzeka ku:
– Inqubo yokusha (ukusabela kwamakhemikhali nokuxubana emazingeni okushisa aphezulu)
– Ukudluliselwa kokushisa okunomehluko omkhulu wokushisa, isibonelo phakathi kwelangabi kanye nobuso bepayipi
– Ukungqubuzana kokugeleza emaceleni egesi namanzi/nomusi (ukwehla kwengcindezi)
Ngokuhlaziywa kokuzivocavoca, abaqhubi bangathola ukuthi nakuba ukushisa okuthile kudluliselwa emanzini, ikhwalithi yamandla iyehla ngenxa yokungalungiseki kwenqubo. Lokhu kusiza ekubekeni phambili ukuthuthukiswa: isibonelo, ukuthuthukisa ukusatshalaliswa kukaphethiloli womoya, ukwandisa ukubuyiswa kokushisa, noma ukunciphisa i-ΔT ephezulu kakhulu ku-heat exchanger.
Umphumela Wezimo Zokusebenza Ekusebenzeni Kokushisa
Ukusebenza kwebhoyila kuthonywa kakhulu yingcindezi, izinga lokushisa kanye nekhwalithi yamanzi.
1. Ingcindezi yokusebenza
Ukwandisa ingcindezi kwandisa izinga lokushisa lokugcwala. Ngezidingo ezithile zenqubo, lokhu kungandisa ubuningi bamandla esitimu. Kodwa-ke, ukucindezela okuphezulu kudinga izinto eziqinile nokulawula okuqinile.
2. Izinga lokushisa lamanzi okuphakelayo
Uma izinga lokushisa lamanzi okuphakelwa liphezulu, kulapho ukushisa okuncane ibhoyila elikudingayo ukuze kufezwe izimo zomusi ezifiselekayo. Ngakho-ke, i-deaerator kanye ne-economizer zidlala indima ebalulekile.
3. Ikhwalithi yamanzi (ukwelashwa)
Amazinga e-oxygen ancibilikisiwe, ubulukhuni, kanye ne-TDS kuthinta ukukala kanye nokugqwala. Ukukala kwandisa ukumelana nokushisa, okuholela ekudlulisweni kokushisa okubi, amazinga okushisa ensimbi akhuphukile, ukwehla kokusebenza kahle, kanye nengozi eyengeziwe yokwehluleka kwepayipi.
Isu Lokuthuthukisa Ukusebenza Kahle Okusekelwe Ku-Thermodynamics
Ezinye izinyathelo ezisebenzayo ezihlobene ngqo nokutadisha i-thermodynamics zifaka:
– Ukufakwa/ukwenziwa ngcono kwe-economizer ukuze kusetshenziswe ukushisa kwegesi yokukhipha umoya ekufudumaleni kwamanzi okuhambisa amanzi.
– Isifudumezi somoya sokwandisa izinga lokushisa lomoya ovuthayo, sithuthukise ukuzinza komlilo kanye nokusebenza kahle.
– Ukulawula ukunqunywa kwe-O₂ ukuze kulondolozwe umoya owengeziwe ofanele.
- Ukulungiswa kokushisa kanye nokubuyiselwa kokushisa ukuze kuncishiswe ukulahleka kwe-enthalpy.
– Ukulungiswa kwendawo yokudlulisa ukushisa (ukuhlanza i-soot/scale) ukuze kugcinwe izinga lokudlulisa ukushisa liphezulu.
– Ukuvikela okuhle emapayipini anomusi, amadramu kanye namagobolondo.
– Ukuqapha okuqhubekayo kwamapharamitha e-thermodynamic (T, P, izinga lokugeleza, igesi yoketshezi i-O₂/CO2) ukuze kutholakale ukuphambuka kusenesikhathi.
Isiphetho
Ucwaningo lwe-thermodynamics yobunjiniyela ezinhlelweni zebhoyila yezimboni lunikeza uhlaka olunamandla lokuhlaziya lokuqonda ukuthi amandla avela kuphethiloli aguqulwa kanjani abe umusi, kuyilapho futhi ekhomba amaphuzu okulahlekelwa anciphisa ukusebenza kahle. Ngokusebenzisa ibhalansi yamandla (uMthetho Wokuqala) futhi ehambisana nombono wokuzivocavoca (uMthetho Wesibili), onjiniyela bangenza izinqumo eziqhutshwa idatha ukuthuthukisa ukusebenza kahle, ukunciphisa ukusetshenziswa kukaphethiloli, ukugcina ukuthembeka kwemishini, nokwandisa isikhathi sokusebenza kwebhoyila. Ekugcineni, ibhoyila eyenziwe ngcono ngokushisa ayigcini nje ngokusindisa izindleko kodwa futhi isekela ukunciphisa ukukhishwa kwegesi kanye nokusebenza kwezimboni okusimeme kakhudlwana.
