Kab lus no muab cov npe ib kauj ruam ntawm cov lus qhia rau kom raug thiab raug siv cov ntxhuav chav. Kab lus no siv qhov piv txwv teeb meem los pab qhia cov txheej txheem kom nkag mus rau cov ntxhuav chav thiab yuav cuam tshuam qhov txiaj ntsig yog tias tsim nyog.
Nqe Lus Qhia Teeb Meem: Pom qhov hloov pauv hauv enthalpy xav tau kom ua kom sov cov dej ua kua ntawm.1 MPa thiab 40o C mus rau cov cua sov ntau tshaj ntawm.3 MPa thiab 190o C.
Cov kauj ruam
Kauj Ruam 1. Txheeb xyuas yam peb tab tom sim nrhiav thiab sau daim ntawv teev cov txiaj ntsig
Enthalpy hloov pauv tau piav raws li ∆H = Hfinal - Hinitial. Tinitial = 40o C, Tfinal = 190o C, Pinitial =.1 MPa, Pfinal =.3 MPa
Kauj Ruam 2. Nrhiav Cov Ntsiab Lus Steam nyob tom qab ntawm koj phau ntawv uas muaj txiaj ntsig rau dej txaus
Feem ntau sau lo lus Kub Kub thiab Siab Siab. (Thawj nplooj ntawv yuav zoo li cov duab hauv qab no)
Kauj Ruam 3. Nrhiav qhov ntsuas kub 40o C hauv kab laug sab laug ntawm lub rooj
Kauj Ruam 4. Ua raws nws hla lub rooj mus rau kab enthalpy
Labeled HL, HVap or HV. Peb tsuas yog paub tias peb cov kua dej thaum pib yog kua, yog li peb yuav siv cov kua enthalpy tus nqi, HL, raws li peb tus nqi nkag thawj zaug. HL = 167.53 kJ/kg
Kauj Ruam 5. Tam sim no nrhiav Superheated Steam table
Kauj Ruam 6. Txheeb xyuas qhov muaj nuj nqis txheeb ze rau peb qhov siab kawg (0.3 MPa)
Kauj Ruam 7. Nrhiav peb qhov ntsuas kub kawg (190o C)
Kauj Ruam 8. Paub txog tias 190 tsis tau teev nyob hauv kab ntawv kub, yog li peb yuav tsum sib tham
Kev cuam tshuam qhov txiaj ntsig muab rau peb qhov kev kwv yees zoo tshaj plaws, thaum qhov xav tau kub lossis siab nyob nruab nrab ntawm ob qhov muaj txiaj ntsig. Interpolating ua raws cov qauv, HD (xav enthalpy) = [(H_hi-H_low)/(T_hi-T_low)*(T_final-T_low)]+H_low Rau peb qhov teeb meem piv txwv, Tfinal = 190o C
Kauj Ruam 9. Nrhiav qhov ntsuas kub nyob saum toj thiab qis dua 190o C, Thi thiab Tlow
Hauv qhov no lawv yog 200oC thiab 150o C.
Kauj Ruam 10. Tam sim no pom qhov sib piv enthalpy qhov tseem ceeb rau 150o C thiab 200o C, Hhi thiab Hlow
Kauj Ruam 11. Ua raws kab zauv saum toj no txhawm rau nrhiav tus nqi sib xyaw enthalpy ntawm 190o C
[(2865.9-2761.2)/(200-150)*(190-150)] +2761.2 H190 = 2844.96 kJ/kg
Kauj Ruam 12. Rho tawm peb thawj tus lej enthalpy ntawm 40o C (167.53 kJ/kg) los ntawm peb tus lej enthalpy zaum kawg ntawm 190o C (2844.96 kJ/kg), txhawm rau nrhiav kev hloov pauv hauv enthalpy xav tau kom sov dej los ntawm nws cov kua theem mus rau lub zog ua kom sov
Cov lus teb yog muab hauv qab no.
∆H = 2844.96 kJ/kg - 167.53 kJ/kg = 2677.43 kJ/kg
