11 02 20sol

Pagina 1

Problem 1 Problem data Data from charts / tables flue gas flow 190 flue gas temperature 480 cP flueg gases, kJ/kg-K 1.07 m of steam at turbine inlet, kg/s 20 T of steam at turbine inlet, °C 450 pressure at turbine inlet, bar 30 stack temp. of HRSG, °C 200 isentropic eff of HP turbine 0.9 isentropic eff of LP turbine 0.88 pressure drops of SH, bar 2 pressure drops of ECO, bar 5 HRSG heat losses, % 0.5 DT subcooling evaporator, °C 5 fluid power of feedwater pump, kW 100 pressure drop of steam bled, bar 2 cond pressure, bar 0.07 hydraulic eff of pump condensate 0.75 elettric-mecc eff. of pumps 0.81 electric-mecc efficiency of turbine 0.92 Results Pinch point temp calculation enthalpy h1, kJ/kg 3345 from Mollier diagram evaporator pressure (p8), bar 32.00 p1+pressure drop SH eva temp (p8), °C 237.5 econ outlet temperature (T7), °C 232.5 Teva - DTsubcooling water enth at eco outlet (h7), kJ/kg 1002 DT pinch point, °C 10.90 from energy balance of the HRSG control volume including SH and EVA mfluegas*cp*(TOT-Teva-DTpp)*(1-losses)=m1*(h1-h7) T6 calculation enthalpy of water at HRSG inlet (h6) 512.7 from the energy balance of the whole HRSG pressure of water at HRSG inlet (p6) 37.00 mfluegas*cp*(TOT-Tstac k)*(1-losses)=m1*(h1-h6) water heat capacity (cW) = 4.45 temperature of water at HRSG inlet 121.6 estimated as Tsat(p6)-(hsat(p6)-h6)/cW 121.53 pdea calculation dea outlet enthalpy (h5), kJ/kg 507.7 h6 - pump work dea pressure (p5), bar 2.05 pressure of sat liquid with h=h5 net power of steam cycle El Power of feedwater pump, kWel 123 fluid power / mech-el efficiency turbine extraction pressure, bar 4.05 as deareator pressure plus the valve pressure drop entropy at HP turbine inlet (s1), kJ/kg-K 7.085 from Mollier dia g (hSP1iso), kJ/kg 2823 from Mollier diag (hSP1), kJ/kg…