Question

The axial flow steam turbine rotor shown in Fig. P12.69 has a blade outer radius RO 2.40 ft, a blade inner radius Ri 2.00 ft, a steam inlet pressure p1 200 psia, a steam inlet density p1- 0.296 lbm/t3, and an inlet absolute velocity V1 1000 f/s making an angle of 70° with the axial direction. The steam outlet pressure p2 50 psia and outlet density is 0.1014 Ibm/t3. B2 40 The rotor rotates at 3600 rpm. Using a blade velocity at the blade midheight (R 2.20 ft), find the power transferred from the steam to the rotor. Fig. P12.69 го- Vi Turbine blade W2 Section AA

Answer 1

Ro= 2.40 ft Rm 2.20 FE Ro 20 0(1 Pa VI = 1000 ft/sec V2. Turbine Blade Wi 32 01014 Ibm/rt3 Porwer transfered from steam to turbine

U= Blade Velocity = 끄DmN . TTx4. 40 x 360 825 Vwi Velocity of whirt at inlet V cosa1000 cos 2o VFVelocity of flow at inlet Visina, looo sin 2o 60 60 342.02-559.765 lbm.lsec . į AfVfl By mass conseruation 0.296x Пх 4.40x(2-40-2) x 296 x 342-02 993.401 ftlsec VP2Vf2.V o 1014 998: 401-1553 ,237 ft/sec VF2-1/2 si nPa y2= VF2 - . sin P2 sin40 /W2= Velocity of nohí aP arou ter VW2 1553.237 cos 40-1189, 848 ft/sec . 559.765 [939.69 t l 189.848] x 829.38 = g88654830-7 lb ft/sec 1797554 238 HP