File:3_Isentropic Turbine.EES
10/10/2014 4:16:47 AM Page 1
EES Ver. 9.701: #3770: For use only by students and faculty Mechanical Engineering Dokuz Eylül University, TURKEY
{!INPUTS}
F$ = 'Water'
"Type of fluid"
m_dot = 100 [kg/s]
"Mass flowrate of fluid"
T[1] = converttemp(C,K, 650 [C])"Temperature of fluid at the inlet
section"
P[1] = 4 [MPa]
"Pressure of fluid at the inlet
section"
P[2] = 0.01 [MPa]
"Pressure of fluid at the outlet
section"
eta_t_2 = 0.84 [-]
"Evaluate the properties at the inlet"
h[1] = enthalpy(F$, T=T[1],P=P[1])
s[1] = entropy(F$, T=T[1], P=P[1])
h_s[1] = h[1]
s_s[1] = s[1]
"Evaluate the properties at the outlet"
s_s[2] = s[1]
h_s[2] = enthalpy(F$, s=s_s[2],P=P[2])
x_s[2] = quality(F$, s=s_s[2],P=P[2])
T_s[2] = temperature(F$, s=s_s[2],P=P[2])
{! (a) Turbine Work output}
W_s_turbine = m_dot*(h[1] - h_s[2])
W_turbine = W_s_turbine*eta_t_2
{! (b) Entropy generation}
"Entropy balance equation"
S_dot_gen = m_dot*(s[2] - s[1])
"Energy balance equation"
(h[1]-h_s[2])*eta_t_2 = (h[1]-h[2])
"Entropy at the exit"
s[2] = entropy(F$, h=h[2], P=P[2])
File:3_Isentropic Turbine.EES
10/10/2014 4:16:47 AM Page 2
EES Ver. 9.701: #3770: For use only by students and faculty Mechanical Engineering Dokuz Eylül University, TURKEY
SOLUTION
Unit Settings: SI K MPa kJ mass deg
ht,2 = 0.84 [-]
Sgen = 70.82 [kJ/s-K]
F$ = 'water'
W s,turbine = 141349 [kJ/s]
m = 100 [kg/s]
W turbine = 118733 [kJ/s]
No unit problems were detected.
Arrays Table: Main
hi
hs,i
Pi
si
ss,i
Ti
Ts,i
[kJ/kg]
[kJ/kg]
[MPa]
[kJ/kg-K]
[kJ/kg-K]
[K]
[K]
1
2
3790
2602
3790
2376
4
0.01
7.497
8.205
7.497
7.497
xs,i
923.2
319
0.9132
Water
1
h [kJ/kg]
3500
P1 = 4 MPa
P2 = 0.01 MPa
3000
2500
2
2s
0.9
0.8
2000
0.6
1500
5.0
6.0
7.0
8.0
s [kJ/kg-K]
9.0
10.0