Question

Q.7 A combined cycle power plant as shown below that produces net gas turbine power of (ie W -W. = 147 MW). Determine (a) the net power produced in MW and (b) the overall thermal efficiency. Assume Ps = 100 kPa, Ts = 300 K, Po= 13,600 kPa, T6 = 690 K, P, = 13,000 kPa, T, = 1,580 K, P = 100 kPa, Tg = 900 K, P, = 100 kPa, T, = 400 K;P; = 10 MPa, Tz = 500°C, P, = P4 = 10 kPa. Assume np = 0.8 and 1st = 0.85. c. ch duco condenser

Answer 1

RSG 7 Ps= lookPa 16 = 13,600 kla P7 130ookPa 18 lookPa Pg= lookPa Pse Book 6 = 690 K P - Iseok Poe gook Tg = 4ook ing mass of air in kals Ms = mass of Steam in kals as gas passed through Heat Exchanger Q- mg x opax (TgTs) = x 144) .... (a 8 = lng & pga melha-h2) ingas turbine - 147 MW ng x pg (-10 t12) - ingepg (86-1s) = 147 X103 kW assuming air as working fluid Age 1.005 kJ/kg k ng kl.008 (-900+ 1980 - 630+30) = 144 Klo? g. 504. 374 kg ls

Bu Steam tycle, P = lokia @ Sod.liquid So hy = hfa lokPa = 191.01 kJ/kg & Os of Clokea= 0.000000 m/ : P₂ = P2 = 10MPa so (copump) actreal = (Wpump lideal npump - Vi (P2 - P.) 20.000000 (10,000 - to) no upung = 12.61 kJ/kg hachi = 12.61 A2z 12.61 + 191.01 204.42 kJ/kg 22 500'c le Page lompa ( from Steam table) ho 3375.1 kg/kg S8 = 6.999s killige from ear cas 504.375X1.005 ( 300-400) = mis (3375-1-204.42) mg 79.935 kg/

Pu Steam turbine Pa z lokea 1st = 0.05 = ( t) actual (with ideal for Wolideal Sg = Sq = 6.5995 = (Sf + X4 Sff) @ tokia - 0.6492 + x4x 7 4996 Xq = 0.793 Chalideal = (he exq hfq) @ tokla - 191.01 +0.793x 2397.1 = 2088-14 kalke So ce a 0.85 & ha-lhe act ho-holidel tace 3375 1-2080.79 (Wit) actual = 109 3. 406 kJ/kg ( Steam & mg xursalbal - pure] - 79.935 [1093-406 - 19.61] - 06.393 mW a) 6 - Mel power produced = 147 +86.393 283.393 Mw. Noveral & Winet - 233 · 3 9 340 233- 393 x103 Binnet Sin.ce ng x Cpg (12-16) z 293-393 Xl03 504.375X1-006 (1580-690) & 51.73%