Common Data for Question 1 & 02
In a steam power plant operating on the Rankine cycle, steam enters the turbine at 4 MPa, 3500C and exits at a pressure of 15 kPa. Then it enters the condenser and exits as saturated water. Next, a pump feeds back the water to the boiler. The adiabatic efficiency of the turbine is 90%. The thermodynamic states of water and steam are given in table.
|
State
|
h (kJ/kg)
|
s(kJ/kg.K)
|
v(m3/kg)
|
|
Steam 4Mpa, 350 C
|
3092.5
|
6.5821
|
0.06645
|
|
Water 15 kPa
|
hf
|
hg
|
sf
|
sg
|
vf
|
vg
|
|
225.94
|
2599.1
|
0.7549
|
8.0085
|
0.001014
|
10.02
|
h is specific enthalpy, s is specific entropy and v the specific volume; subscripts f and g denote saturated liquid state and saturated vapour state.
- The net work output (kJ/kg) of the cycle is
(a) 498 (b) 775
(c) 860 (d) 957
2 . Heat supplied (kJ/kg) to the cycle is
(a) 2372 (b) 2576
(c) 2863 (d) 3092