Steam enters the turbine of a Rankine cycle at 16 MPa, 560C. The condenser press
ID: 1851725 • Letter: S
Question
Steam enters the turbine of a Rankine cycle at 16 MPa, 560C. The condenser pressure is 8 kPa. The turbine and pump each have isentropic efficiencies of 85%, and the mass flow rate of steam entering the turbine is 120 kg/s. Determine (a) the net power dev Steam enters the turbine of a Rankine cycle at 16 MPa, 560C. The condenser pressure is 8 kPa. The turbine and pump each have isentropic efficiencies of 85%, and the mass flow rate of steam entering the turbine is 120 kg/s. Determine (a) the net power developed, in kW. (b) the rate of heat transfer to the steam passing through the boiler, in kW. (c) the thermal efficiency. Plot each of the quantities in parts (a)Explanation / Answer
At P1 = 16 MPa and T1 = 560 C...we get...h1 = 3464.79 kJ /kg......s1 = 6.5143 kJ/ kg K Assuming isentropic expansion to point 2'... at P2' = P2 = 8 KPa...and s2' = s1 = 6.5143 kJ/kg K... we get...h2' = 2037.34 kJ /kg Now...(h1 - h2) / (h1 - h2') = 0.85...from this we get...h2 = 2251.46 kJ / kg h3 = hf at saturation pressure p3 = p2 = kPa...and x = 0 h3 = 173.8649 kJ / kg v3 = 0.001 kg / m^3 Actual Work done in pump = 0.85 * v3 ( p4 - p3) = h4 - h3 0.003 (16000 - 8) = h4 - 173.8649 h4 = 214.6445 kJ / kg a) Net power developed = m (h1-h2) - m(h4 - h3) = 140706.048 kW b) Rate of heat transfer to steam = m (h1 - h4) = 390017.56 kW c)Thermal Efficiency = Work / heat = 140706.048 / 390017.46 = 0.3607 = 36.07 % I am unable to plot the curves here...some technical issues...refer to the book or google... :)