Question

(1) Q.5 (a) A power station using a Superheated Rankine cycle operates with a boiler pressure of 160 bar and a condenser pressure of 0.045 bar. The turbine has an inlet steam temperature of 575°C, and has an isentropic efficiency of 90.5%. The pump has an isentropic efficiency of 88%. Hence, determine Show the cycle on a T-s diagram in relation to the saturation curves and clearly label all the principal points starting from the exit of the condenser. Sketch the isentropic and actual paths and label them with subscripts “s” and “a” respectively. (4 marks) (11) The enthalpy of the steam at the principal points around the cycle (9 marks) (III) The dryness fraction of the steam at the turbine outlet (1 marks) (IV) The turbine's specific work output (kJ/kg) (1 marks) (V) The specific heat transfer in the boiler (1 marks) (VI) The cycle's thermal efficiency (2 marks) (VII) The specific steam consumption (SSC) of the cycle (2 marks) You may assume that v, = 0.001 *in all cases.

Answer 1

cycle: :- Rankine 3 T 20 25 45 ta' > S At P = 160 bar T= 575 °C > h₂ = 3507.9 3 kulkg kilkg-k 6-5647 53 وہ نے S AL p = 0.045 bar s 45 1989.6 kJ/kg has VL Giver w = 90.5% T Wack = Na rev hz-haa 0.905 hz- has 1 haa T 2.133.83 EJ kg.

124.88 -h, h Ег/ra 2 557-4 E5/Eg hя + х ha hag f 129.88+ х (2 557.4 - 2133 •33 - (2 9.88 х 0.825 , О-оо) m/kg. СРѕ -P] "f ponev О-оо[ 16000 – 4-5 ] 16 кка wporey worev ү/ Wach 16 о: 38 - | Wach 3 4 act pomp = 13-18 N/Fa

hza wp+h; = 18.184. 129.98 =) hza 148.16 KJ/kg Tobine workoutput WX hy-haa 1374.07 KJ leg Heat addition in boiler 3359.74 KT kg Qir hz-hza 1355.89 KJ لا = w Net w-wp kg Whet Thermal eff = Qin 40. 35 % nth com somption Nell Specc°fºc steom 3600 ca SSC = kg kw-hr Net 2.655 kg SSC = kw-ho.