Question

1. A steam turbine has an inlet of 2 kg/s water at 1000 kPa and 350 °C with a velocity of 15 m/s. The exit is at 100 kPa, 150 °C, and very low velocity. Determine the power produced. 2. A small expander (a turbine with a heat transfer) has 0.05 kg helium entering at 1000 kPa, 550 K, and it leaves at 250 kPa, 300 K. The power output on the shaft is measured at 55 kW. Determine the rate of heat transfer neglecting kinetic energies. (Wdot = +55 kW)

Answer 1

m=20g/sec P=1000kpq T = 350°C V = 15m/see Solo A1 condition ! Pa 1000 Rpq 7 2 350°c По Р1 T = 150°C h=3158.2 kJ (vg [from steun table] 2000 At condition 2 P = 100 kpa, T = 150°C h = 2776.6 kJ и | . [{2 см 34eaa tebe | using steady state Energy Equatou blow and ② 2 an hi tri? in h2 tv2 + Wproduce 9 2 [3158.2 + 1527 - 2 [2376-67 - Wprorlue Apredule = 763.425 kJ/sec - 763.42KW 1 763.42 kw AM Solo 0.05ng P = 1000kpa, T 550k 250kpa, T =300k At condition, 1-) ha Enthalpy h = 2874.5 kilig (from daty table of Helium] At condition 2 Enthalpy h2 = 1574 kilug [from data table of Helium] impeliun - P2=

using stead state Energy Equation on [hi] to m Chelt Woutput 0.05 [1574] +55 -0.05 [2874.5 a = -10.025 kN An 1. Plate Heat transfer =-10.025 kw Ang of