Question

QUESTION 2 Q10 A horizontal tube with D-005 and T, - 307K is exposed to team at O2 bar. Determine the average heat transfer coefficient, condensation rate, and heat transferate per unit length of the tube [For simplicity of the problem, make the following usumptions: (1) Laminar film condensation (2) Negible son-condensibles in team The average heat transfer coefficient - 6926 W/m2K, Condensation Rate per unt length of the tube - 1.16-10-2vmand het traiter rate per unit length of the tube – 28.3KW - The wverage heat transfer coefficient = 556 W/m2.K, Condensation Rate per unit length of the tube - 8.12 10 2 km and heat transfer to per unit length of the tube - 1052 The werage heat transfer coefficient - 2669 Wim? Condensation Rate per unit length of the tube - 236-10pm and beat transfer rate per unit nagth of the tube 32.3 m The werage heat transfer coefficient- 7256 W m Condensation Rate per unit fogth of these-526-10-vud heat trane rate per unit length of the the 563

Answer 1

Sleam (0.2600) Ts=307K 전 Solution:- Schematic : - 0 0 - Tube ( D=0.05m) Assumptions:- 1) lamunas folü, 2) Negligible non-condensibles in steam. Calculating propestries from table A-6, Satusated steam (0.2 bar) Tsat. 0.129 KB/m3, hgg = 2358 kl Table A-6, wares, liquid (If = Is + Tsat = 307+333 = 320 K), ll, = 577X106 N-s/m2 = 333 k, fv = KJ/vg' 2 Si = 989.1 kg/m3, Cpt = 4180 J/kg.k Ki = 0.640 W/m-k / m': q' /ngg! where hf こ pe (Tsat - Ts) 3) / nfg Analysis The heat transfer and condensate ales per unit length of the tube are given by , q' = ho (AD) (Tsat. - Ts) and hfe [1 +0.68 Ja] ; Ja = h få 2358 [1 + 0.68 x 4180%(333–30 7 23 58x103 (hy) KJ/vg fos laminas flow condensation ho is given by with c=0-729 ho 0.729 gse (se -Sv) qse (Se-sv) ke se hag " (Tal-Ts). 9.8 x 989.14 (989.1-0.129) X0-64 x 24 32X15 (Five) 577X106 x (333-307) x0.05 hfg' - 2432 ما こ 0.729 hfg' ho = 6926 W/m²K Now, Condensate sate, mis q'. q ho (as) ( Teat-Ts) = 69261 ñ X0.05)(333- 307) 28.3 kW/m 2813 8103 W/m) m'= 1.16x102 kg/s-m ma 24 3 2 X10S (J/kg) Hence, ho = 6926 m 2 Im' = 116x10² 9' = 28.3 q' ņ 2 k? VW m s.m mick