\u00c7in\u2019in a\u00e7\u0131l\u0131m politikalar\u0131 ve \u00c7in klimalar\u0131 (AC) \u00fcreticilerinin \u00e7abalar\u0131n\u0131n ard\u0131ndan uzun y\u0131llar ge\u00e7mesiyle birlikte, \u00c7in k\u00fcresel klima end\u00fcstrisinin merkezi olarak tan\u0131nm\u0131\u015ft\u0131r. 2011 y\u0131l\u0131nda \u00c7in\u2019de \u00fcretilen klima toplam\u0131 raporlara g\u00f6re 139 milyon adet ula\u015fm\u0131\u015f olup, bu rakam k\u00fcresel \u00fcretim hacminin yakla\u015f\u0131k %80\u2019ine tekab\u00fcl etmektedir. Ayn\u0131 zamanda, \u015fehirle\u015fme politikas\u0131, k\u00fcresel \u0131s\u0131nma gibi fakt\u00f6rlerle birlikte talep art\u0131\u015f\u0131 s\u00fcrekli olarak devam etmektedir.<\/p>\n
Genel olarak klima sistemlerinde kullan\u0131lan iki tip boru bulunmaktad\u0131r:<\/p>\n
a. So\u011futucular, buharla\u015ft\u0131r\u0131c\u0131lar gibi \u0131s\u0131 de\u011fi\u015ftirici uygulamalar i\u00e7in boru;<\/p>\n
b. Is\u0131 de\u011fi\u015ftirici uygulamalar d\u0131\u015f\u0131ndaki uygulamalar i\u00e7in boru; \u00f6rne\u011fin d\u0131\u015f \u00fcnite borular\u0131 ile i\u00e7 ve d\u0131\u015f \u00fcniteler aras\u0131ndaki ba\u011flant\u0131 borular\u0131.<\/p>\n
Sonraki k\u0131s\u0131m \u0131s\u0131 transferi gerekti\u011fi i\u00e7in, bak\u0131r borular\u0131n \u00e7ift cidarl\u0131 bak\u0131r lehimli \u00e7elik borularla de\u011fi\u015ftirilmesi m\u00fcmk\u00fcn k\u0131l\u0131nmaktad\u0131r (\u00e7elik malzemenin \u0131s\u0131 iletkenli\u011fi bak\u0131ra k\u0131yasla 1\/8,5 oran\u0131ndad\u0131r; dolay\u0131s\u0131yla \u00e7elik, bak\u0131ra g\u00f6re \u0131s\u0131 kayb\u0131 daha azd\u0131r ve enerji tasarrufu sa\u011flar).<\/p>\n
Yakla\u015f\u0131k hesaplama ile her bir klima seti i\u00e7in 1,5 kg bak\u0131r boruya ihtiya\u00e7 duyulmaktad\u0131r. D\u0131\u015f mek\u00e2n \u00fcnitesi i\u00e7in 0,5 kg, ba\u011flant\u0131 borular\u0131 i\u00e7in ise 1 kg gerekmektedir. 2011 y\u0131l\u0131 \u00fcretim verilerine dayanarak piyasa hacmi yakla\u015f\u0131k 200.000 metrik ton seviyesindedir. T\u00fcm bu bak\u0131r borular \u00e7ift cidarl\u0131 \u00e7elik borularla de\u011fi\u015ftirilirse, bu durum \u00e7ift cidarl\u0131 \u00e7elik boru \u00fcreticileri i\u00e7in b\u00fcy\u00fck bir f\u0131rsat olu\u015ftururken ayn\u0131 zamanda b\u00fcy\u00fck miktarda bak\u0131r kayna\u011f\u0131 tasarrufu sa\u011flanacakt\u0131r.<\/p>\n
Klima borular\u0131 i\u00e7in sat\u0131n alma ile montaj aras\u0131ndaki s\u00fcre genellikle uzundur. \u0130\u00e7 mek\u00e2n \u00fcnitesi borular\u0131 ve ba\u011flant\u0131 borular\u0131 i\u00e7in bu s\u00fcre daha da uzun olabilir. Bu nedenle, \u00e7ift cidarl\u0131 bak\u0131r lehimli \u00e7elik borular\u0131n ya\u015flanma etkisi minimuma indirilerek, kolay b\u00fck\u00fclebilirlik i\u00e7in esneklik sa\u011flanmal\u0131d\u0131r.<\/p>\n
Daha y\u00fcksek sertle\u015fim indeksi (n) de\u011feri, borular\u0131n daha y\u00fcksek uzama oran\u0131na sahip olmas\u0131n\u0131 ve so\u011fuk \u015fekillendirme i\u00e7in daha uygun olmas\u0131n\u0131 sa\u011flar. Di\u011fer yandan, h\u0131zl\u0131 sertle\u015fme e\u011filimi b\u00fckme ve flaring i\u015flemlerini zorla\u015ft\u0131r\u0131r. Dolay\u0131s\u0131yla klima uygulamalar\u0131 i\u00e7in kullan\u0131lan Bundy borular, kabul edilebilir uzama oran\u0131n\u0131 sa\u011flamak amac\u0131yla orta d\u00fczeyde daha d\u00fc\u015f\u00fck bir sertle\u015fim indeksine sahip olmal\u0131d\u0131r.<\/p>\n
a. \u00c7ekme dayan\u0131m\u0131 bir sorun de\u011fildir. \u00c7elik borular i\u00e7in minimum 290 MPa, bak\u0131r borular i\u00e7in ise minimum 270 MPa de\u011feridir.<\/p>\n
b. \u00c7elik borular\u0131n akma dayan\u0131m\u0131 minimum 180 MPa iken, klima sekt\u00f6r\u00fc kolay \u015fekillendirme i\u00e7in daha d\u00fc\u015f\u00fck akma dayan\u0131m\u0131 tercih eder; ideal olarak 140 MPa\u2019n\u0131n alt\u0131nda olmal\u0131d\u0131r.<\/p>\n
c. Uzama: \u00c7elik borular i\u00e7in %25 gerekliyken, klima sekt\u00f6r\u00fc minimum %38, tercihen %40 uzama istemektedir.<\/p>\n
Mekanik performans gereksinimlerine g\u00f6re, ultra d\u00fc\u015f\u00fck karbonlu \u00e7elik (karbon oran\u0131 %0,004\u2019ten az) bu hedefleri kar\u015f\u0131layabilir. \u00c7ift cidarl\u0131 \u00e7elik borular\u0131n orijinal karbon bile\u015fimi %0,02\u2013%0,08 aral\u0131\u011f\u0131ndad\u0131r.<\/p>\n
\u00c7elik borular i\u00e7in belirlenen orijinal standartlarda, 8 mm\u2019den k\u00fc\u00e7\u00fck \u00e7apl\u0131 borular i\u00e7in b\u00fckme kal\u0131b\u0131 \u00e7ap\u0131 boru \u00e7ap\u0131n\u0131n 3 kat\u0131 olarak tan\u0131mlanm\u0131\u015ft\u0131r; 8 mm\u2019den b\u00fcy\u00fck \u00e7apl\u0131 borular i\u00e7in bu de\u011fer 6 kat olarak belirlenmi\u015ftir. Ancak klima sistemlerinde yap\u0131lan boru b\u00fckme i\u015flemleri genellikle boru \u00e7ap\u0131n\u0131n 3 kat\u0131ndan daha k\u00fc\u00e7\u00fckt\u00fcr.<\/p>\n
Klima sistemlerinde kullan\u0131lan bak\u0131r borular\u0131n deformasyon oran\u0131 genellikle 1,15\u20131,23 aras\u0131nda olmal\u0131d\u0131r. (Deformasyon oran\u0131, b\u00fckme i\u015flemi sonras\u0131nda elde edilen elips kesitli borunun b\u00fcy\u00fck ekseninin k\u00fc\u00e7\u00fck eksene oran\u0131d\u0131r.)<\/p>\n
a. NSS Testi<\/p>\n
Boru \u00e7e\u015fitlerinin \u00e7o\u011fu d\u0131\u015f atmosferde ve t\u00fcm hava ko\u015fullar\u0131nda kullan\u0131l\u0131r; borular\u0131n d\u0131\u015f y\u00fczeyinde suyun yo\u011funla\u015fmas\u0131 olduk\u00e7a yayg\u0131nd\u0131r. Klima uygulamalar\u0131 i\u00e7in kullan\u0131lan borular i\u00e7in genellikle en az 500 saatlik NSS testi talep edilir. Baz\u0131 \u00fcreticiler hatta 1000 saatlik testi \u015fart ko\u015far.<\/p>\n
b. Kaynak Etkisi<\/p>\n
Borular bazen kaynakla birle\u015ftirilir. Kaynak s\u0131cakl\u0131\u011f\u0131 800\u2103 \u00fczerindedir ve alev s\u0131cakl\u0131klar\u0131 daha da y\u00fcksektir. Borular\u0131n d\u0131\u015f y\u00fczey kaplamas\u0131 erimeye veya bozulmaya u\u011framamal\u0131d\u0131r.<\/p>\n
c. Uzama<\/p>\n
Borular korozyona kar\u015f\u0131 koruyucu kaplamalarla kaplan\u0131r ve bu kaplamalar, borular b\u00fck\u00fcld\u00fc\u011f\u00fcnde, flair (a\u00e7\u0131k u\u00e7) yap\u0131ld\u0131\u011f\u0131nda veya daralt\u0131ld\u0131\u011f\u0131nda ayr\u0131lmamal\u0131d\u0131r.<\/p>\n
d. Kaynaklanabilirlik<\/p>\n
Borular\u0131n d\u0131\u015f y\u00fczeyi bak\u0131r borularla kaynaklanabilir olmal\u0131d\u0131r. Bu gereksinim, d\u0131\u015f y\u00fczey kaplama t\u00fcrlerini s\u0131n\u0131rlar ve ayn\u0131 zamanda kaynak zorlu\u011funu art\u0131r\u0131r.<\/p>\n
Bak\u0131r lehimli \u00e7elik borular\u0131n kal\u0131nt\u0131s\u0131 160 mg\/m\u00b2 iken, klima uygulamalar\u0131 25\u201338 mg\/m\u00b2 aral\u0131\u011f\u0131nda bir kal\u0131nt\u0131 de\u011ferini gerektirmektedir.<\/p>\n
Klima bak\u0131r borular\u0131 elle kaynaklan\u0131r. Kaynak kalitesi operat\u00f6r\u00fcn deneyim ve becerisine ba\u011fl\u0131d\u0131r; ayr\u0131ca elle kaynak i\u015flemi s\u0131cakl\u0131k ve kaynak s\u00fcresi a\u00e7\u0131s\u0131ndan tam olarak kontrol edilemedi\u011finden, so\u011fuk lehim olu\u015fma ihtimali y\u00fcksektir. Ayr\u0131ca kaynak i\u015fleminin y\u00fczey p\u00fcr\u00fczl\u00fcl\u00fc\u011f\u00fcne etkisi, yenileme s\u00fcre\u00e7lerinde \u00f6nemli bir sorun haline gelebilir.<\/p>\n
Baz\u0131 \u00e7al\u0131\u015fmalar ve deneyler ger\u00e7ekle\u015ftirdik. Numuneler klima sistemlerinde test edildi ve 40 sayfadan fazla bir rapor haz\u0131rlanm\u0131\u015ft\u0131r. Ger\u00e7ek \u00fcr\u00fcn testleri sonras\u0131nda b\u00fcy\u00fck klima \u00fcreticilerinden tan\u0131nma kazand\u0131k ve \u00f6n\u00fcm\u00fczdeki a\u015famada k\u00fc\u00e7\u00fck miktarlarda uygulama f\u0131rsat\u0131n\u0131 d\u00f6rt g\u00f6zle bekliyoruz.<\/p>\n
Yukar\u0131daki de\u011ferlendirmeler do\u011frultusunda, bak\u0131r borular\u0131n \u00e7ift cidarl\u0131 bak\u0131r lehimli \u00e7elik borularla de\u011fi\u015ftirilmesinin y\u00fcksek d\u00fczeyde uygulanabilir oldu\u011fu sonucuna vard\u0131k. Ancak bu de\u011fi\u015fimin ger\u00e7ekle\u015fmesi i\u00e7in \u00e7\u00f6z\u00fclmesi gereken teknik engeller mevcuttur ve bu engeller t\u00fcm sekt\u00f6r\u00fc zorlamaktad\u0131r.<\/p>\n
Ayn\u0131 zamanda, klima sekt\u00f6r\u00fc yeni teknolojileri do\u011frulamak ve kabul etmek i\u00e7in daha uzun bir s\u00fcreye ihtiya\u00e7 duyar. Bak\u0131r borular\u0131n \u00e7ift cidarl\u0131 bak\u0131r lehimli \u00e7elik borularla de\u011fi\u015ftirilmesi i\u00e7in hen\u00fcz uzun bir yol vard\u0131r.<\/p>\n