/*
Example Problem 4.10
***************************
*/

// a) Turbine power

// Mass balance

0 = mdot1 - mdot2
0 = mdot3 - mdot4
0 = mdot4 - mdot5

// Energy balance

Wdot = mdot1 * (h1 - h2) + mdot3 * (h3 - h5)

// known conditions

p1=14.7 	// lbf/in2
T1=860 	      // R
p2=14.7
T2=720            // R
av1=2*10^5     // ft3/min
rbar=1545
m=28.97
mdot3=275
p3=40
T3=562
x5=0.93
p5=1
p4=p3

// Mass flow rate and properties

mdot1 = av1 * p1 * 144 / (rbar/m) / T1
  
h1 = h_T("Air", T1)
h2 = h_T("Air", T2)
h3= h_PT("Water/Steam", p3, T3)
h5 = hsat_Px("Water/Steam", p5, x5) 

// b) Temperature at turbine input: T4

// balance of energy in the boiler

0 = mdot1 * (h1 - h2) + mdot3 * (h3 - h4)

T4 = T_Ph("Water/Steam", p4, h4)  

T4F = T4 - 460

// c) Gain ($/year) for 8000 h of annual operation

VA = Wdot * 60 / 3413 * 8000 * 0.08