Ivalvu yokunceda ukhuseleko, ekwaziwa ngokuba yivalvu yokhuseleko olugqithisileyo, sisixhobo sokunciphisa uxinzelelo oluzenzekelayo esiqhutywa luxinzelelo oluphakathi. Ingasetyenziswa njengevalvu yokhuseleko kunye nevalvu yokunceda kuxhomekeke kwisicelo.

Ukuthatha iJapan njengomzekelo, zimbalwa kakhulu iinkcazo ezicacileyo zeevalvu zokhuseleko kunye neevalvu zokunceda. Ngokubanzi, izixhobo zokhuseleko ezisetyenziselwa izitya ezinkulu zokugcina amandla ezifana neebhoyila zibizwa ngokuba ziivalvu zokhuseleko, kwaye ezo zifakwe kwiipayipi okanye kwezinye izakhiwo zibizwa ngokuba ziivalvu zoncedo. Nangona kunjalo, ngokwemigaqo "yeMigangatho yoBugcisa bokuVeliswa koMbane oTshisayo" yoMphathiswa wezoRhwebo lwaMazwe ngaMazwe kunye noShishino lwaseJapan, iindawo ezibalulekileyo zokuqinisekisa ukhuseleko lwezixhobo zichaza ukusetyenziswa kweevalvu zokhuseleko, ezifana neebhoyila, ii-superheater, ii-reheater, njl. Kwimeko apho icala elisezantsi levalvu yokunciphisa uxinzelelo kufuneka liqhagamshelwe kwibhoyila kunye ne-turbine, kufuneka kufakwe ivalvu yoncedo okanye ivalvu yokhuseleko. Ngale ndlela, ivalvu yokhuseleko ifuna ukuthembeka okungaphezulu kunevalvu yoncedo.

Ukongeza, kwimithetho yolawulo lwegesi oluphezulu lweSebe leMisebenzi laseJapan, kwimithetho yeSebe lezoThutho kunye nemibutho yeenqanawa kuwo onke amanqanaba, ekuchongweni nasekumiselweni komthamo wokukhupha okhuselekileyo, sibiza ivalvu eqinisekisa umthamo wokukhupha ngokuthi yivalvu yokhuseleko, kwaye ivalvu engaqinisekisi umthamo wokukhupha ngokuthi yivalvu yokunceda. ETshayina, nokuba ivuliwe ngokupheleleyo okanye ivuliwe kancinci, ibizwa ngokuba yivalvu yokhuseleko xa iyonke.

1. Isishwankathelo

Iivalvu zokhuseleko zizixhobo ezibalulekileyo zokhuseleko kwiibhoyila, izitya zoxinzelelo kunye nezinye izixhobo zoxinzelelo. Ukuthembeka kokusebenza kwazo kunye nomgangatho wokusebenza kwazo kunxulumene ngokuthe ngqo nokhuseleko lwezixhobo kunye nabasebenzi, kwaye kunxulumene kakhulu nokugcinwa kwamandla kunye nokukhuselwa kwendalo. Nangona kunjalo, abanye abasebenzisi kunye namasebe oyilo bahlala bekhetha imodeli engalunganga xa bekhetha. Ngenxa yesi sizathu, eli nqaku lihlalutya ukukhethwa kweevalvu zokhuseleko.

2. Inkcazo

Ezi zibizwa ngokuba ziivalvu zokhuseleko ngokubanzi ziquka iivalvu zokunceda. Ngokwemigaqo yolawulo, iivalvu ezifakwe ngqo kwiibhoyila zomphunga okanye uhlobo lwezitya zoxinzelelo kufuneka zivunywe lisebe lolawulo lobuchwephesha. Ngengqiqo encinci, zibizwa ngokuba ziivalvu zokhuseleko, kwaye ezinye ngokubanzi zibizwa ngokuba ziivalvu zokunceda. Iivalvu zokhuseleko kunye neevalvu zokunceda ziyafana kakhulu kwisakhiwo kunye nokusebenza. Zombini zikhupha ngokuzenzekelayo i-internal medium xa uxinzelelo lokuvula lugqithile ukuqinisekisa ukhuseleko lwezixhobo zokuvelisa. Ngenxa yokufana okubalulekileyo, abantu badla ngokubhidanisa ezi zimbini xa bezisebenzisa. Ukongeza, ezinye izixhobo zokuvelisa zikwachaza ukuba naluphi na uhlobo lunokukhethwa kwimithetho. Ke ngoko, umahluko phakathi kwezi zimbini uhlala ungakhathalelwa. Ngenxa yoko, kuvela iingxaki ezininzi. Ukuba sifuna ukunika inkcazo ecacileyo yezi zimbini, singaziqonda ngokwenkcazo ekwinxalenye yokuqala ye-ASME Boiler kunye nePressure Vessel Code:

(1)Ivalvu yokhuseleko, isixhobo sokunciphisa uxinzelelo oluzenzekelayo esiqhutywa luxinzelelo olungaguqukiyo lwesixhobo esiphambi kwevalvu. Sibonakala ngokuvula ngokupheleleyo okuvuleka ngequbuliso. Sisetyenziswa kwizicelo zegesi okanye zomphunga.

(2)Ivalvu yokunceda, ekwaziwa ngokuba yi-overflow valve, sisixhobo sokunciphisa uxinzelelo oluzenzekelayo esiqhutywa luxinzelelo olungaguqukiyo lwe-medium ephambi kwevalvu. Ivula ngokulingana nokunyuka koxinzelelo oludlula amandla okuvula. Isetyenziswa kakhulu kwiindawo zokusetyenziswa kolwelo.