Izihloko mayelana neMishini Yokuqandisa
Isiqandisi siyinjini yokushisa esebenza ngokuphambene. Ngakho-ke, injini yokushisa ithatha ukushisa kusuka esifundeni esinokushisa okuphansi bese ikulahla ikuyise esifundeni esinokushisa okuphezulu. Ukuze le nqubo yenzeke, injini kumele yenze umsebenzi. Kodwa-ke, ukushisa ngokwemvelo kugeleza kusuka esifundeni esinokushisa okuphezulu kuya esifundeni esinokushisa okuphansi. Ukushisa akukwazi ukugeleza ngokwakho kusuka esifundeni esinokushisa okuphansi kuya esifundeni esinokushisa okuphezulu. Lokhu kuhambisana nesitatimende sikaClausius okukhulunywe ngaso ngaphambilini. Ngenqubo eyenzeka esiqandisini, isitatimende sangaphambilini sikaClausius singabhalwa kanje:
Akunakwenzeka ukuthi umshini wokuqandisa (osebenza ngomjikelezo) uhambise ukushisa kusuka endaweni enezinga lokushisa eliphansi kuya endaweni enezinga lokushisa eliphezulu, ngaphandle kokwenza umsebenzi ( Umthetho wesibili we-thermodynamics - isitatimende sikaClausius).
Umbhalo obhalwe ngomluki uyisitatimende esikhethekile somthetho wesibili we-thermodynamics. Lesi sitatimende sisebenza kuphela emishinini yokuqandisa. Inqubo yokushintsha uhlobo lwamandla nokudlulisa i-eamandla avuliwe 
Umshini wokupholisa ubukeka njengomdwebo ongezansi.
Umshini usebenza (W) ukuthatha ukushisa endaweni enezinga lokushisa eliphansi (Q L ) bese ukhulula ukushisa uye endaweni enezinga lokushisa eliphezulu (Q H ) . Ngokusekelwe ekulondolozweni kwamandla, kungaphethwa ngokuthi Q L + W = Q H.
Uma igama elithi ukusebenza kahle lisetshenziswa ezinjinini zokushisa, khona-ke emishinini yokuqandisa kusetshenziswa igama elithi coefficient of performance (KK). I-coefficient of performance (KK) yomshini wokuqandisa iyisilinganiso esiphakathi kokushisa okudluliselwe kusuka endaweni yokushisa ephansi (Q L ) kuya emsebenzini (W) owenziwe ukudlulisa ukushisa. Ngokwezibalo, lokhu kungabhalwa kanje:
Uma ufuna ukuveza i-coefficient yokusebenza komshini wokuqandisa ngamaphesenti, vele uphindaphinde lesi sibalo ngo-100%. I-coefficient yokusebenza komshini wokuqandisa ofanele (i-Carnot coefficient yokusebenza komshini wokuqandisa):
Kunemishini eminingana yokupholisa esivame ukuyisebenzisa, okuhlanganisa amafriji, ama-air conditioner (AC) kanye nama-heat pump.
Isiqandisisi
I-Condenser = iguqula umhwamuko ube uketshezi, i-compressor = ukucindezela. Ama-coil okupholisa avame ukutholakala ngaphakathi kwesiqandisi, kuyilapho ama-coil e-condenser etholakala ngaphandle kwesiqandisi (ngemuva kwesiqandisi).
Ngaphakathi kwama-coil kukhona uketshezi olusesilinganisweni sesigaba (olukhona ezimweni zoketshezi kanye nomswakama). Lolu ketshezi lwaziwa ngokuthi yi-refrigerant. I-refrigerant eyayivame ukusetshenziswa esikhathini esidlule kwakuyi-freon. I-Freon ayisasetshenziswa namuhla ngoba ukukhishwa kwayo kungalimaza ungqimba lwe-ozone.
Injini ye-compressor (eqhutshwa ugesi) idonsa i-refrigerant (esesimweni somusi) bese iyicindezela ngokushesha. Ngenxa yokucindezela kwe-adiabatic, izinga lokushisa lomhwamuko liyakhuphuka. Njengoba izinga lokushisa likhuphuka, ingcindezi yomhwamuko nayo iyakhuphuka. Umehluko wokushisa phakathi kwe-compressor (izinga lokushisa eliphezulu) kanye ne-condenser (izinga lokushisa eliphansi) kubangela ukuthi umhwamuko wokushisa okuphezulu, onengcindezi ephezulu ugeleze ngamakhoyili e-condenser atholakala ngemuva kwesiqandisi.
Izinga lokushisa lomusi liphakeme kunezinga lokushisa lomoya ozungezile, ngakho-ke uma ugeleza nge-condenser coil, umusi ukhipha ukushisa uye emoyeni ozungezile. Ngenxa yokuthi ugoqene yi-condenser, umusi uyaphola bese uphenduka uketshezi. Uma ugeleza nge-expansion valve, i-refrigerant ephenduke uketshezi iyanda ngokushesha. Ukuba khona kwe-adiabatic expansion kubangela ukuthi uketshezi lubanda kakhulu (izinga lokushisa lalo liyehla). Uketshezi olubandayo lugeleza ngaphakathi kwe-coils ngaphakathi kwefriji. Ngenxa yokuthi uketshezi olukuma-coils lubanda kakhulu kunomoya osefrijini, ukushisa kumuncwa uketshezi kuze kube yilapho i-refrigerant ishintsha ibe umhwamuko (uketshezi lumunca ukushisa esiqandisini). I-refrigerant ephenduke umhwamuko imuncwa yi-compressor motor bese icindezelwa ngokushesha. Njalo njalo… (inqubo iphindaphindwa futhi). Ngenxa yokuthi ukushisa ngaphakathi kwefriji kuthuthela kuketshezi olungaphakathi kwe-coils, isiqandisi siyabanda.
I-AC (isithambisi-moya)
Nakuba ukwakheka kwedivayisi kuhlukile, isimiso esiyisisekelo sokusebenza kwe-air conditioner sifana nesesiqandisini. Kulokhu, isiqandisi siyigumbi. Ngokuvamile, amakhoyili okupholisa atholakala ngaphakathi kwegumbi kuyilapho amakhoyili okupholisa etholakala ngaphandle. Ngemuva kwamakhoyili okupholisa kukhona ifeni. Umsebenzi wefeni umane ukulawula ukujikeleza komoya nokuvuthela amakhoyili okupholisa, ngaleyo ndlela kusheshiswe ukudluliselwa kokushisa phakathi kwamakhoyili okupholisa nomoya ozungezile. Ngokuphambene nalokho, ngemuva kwamakhoyili okupholisa kukhona i-blower, eyaziwa nangokuthi i-blower. Umsebenzi wayo ufana nefeni. Ngenkathi ifeni ivuthela amakhoyili okupholisa ngaphandle, iqondisa ukushisa emoyeni ozungezile, i-blower ivuthela amakhoyili okupholisa ngaphakathi, isakaza umoya opholile kulo lonke igumbi.
Iphampu Yokushisa
Amaphampu okushisa avame ukusetshenziswa ebusika obubandayo. Isimiso sokusebenza sephampu yokushisa sifana nesesiqandisini. Umehluko ukuthi isiqandisini siyithuluzi elisetshenziselwa ukupholisa igumbi, kuyilapho iphampu yokushisa isetshenziselwa ukufudumala igumbi. Ngenkathi isiqandisini senza umsebenzi wokumunca ukushisa okuvela ekamelweni (QL ) nokukukhulula ngaphandle (QH ) , iphampu yokushisa imunca ukushisa okuvela ngaphandle (QL ) bese ikukhiphela ekamelweni (QH ) . Ukushisa okwengeziwe kubangela ukuthi igumbi lifudumale. Lapho kufika ihlobo, iphampu yokushisa ingashintshwa ukuze isebenze njenge-air conditioner (AC).
