Untitled

function x4$(x4) "this function returns a string to indicate the state of steam at point 4"
x4$=''
if (x4>1) then x4$='(superheated)'
if (x4<0) then x4$='(compressed)'
end

P[3] = 20000 {kPa}
T[3] = 500 [C]
P[4] = 10 {kPa}
Eta_t = 1,0 "Turbine isentropic efficiency"
Eta_p = 1,0 "Pump isentropic efficiency"
"Pump analysis"

P[1] = P[4]
P[2]=P[3]
x[1]=0 "Sat'd liquid"
h=Enthalpy(Water;x=x;P=P)
v=Volume(Water;x=x;P=P)
s=Entropy(Water;x=x;P=P)
T=Temperature(Water;P=P;x=x)
W_p_s=v[1]*(P[2]-P[1]) "SSSF isentropic pump work assuming constant specific volume"
W_p=W_p_s/Eta_p
h[2]=h[1]+W_p "SSSF First Law for the pump"
s[2]=Entropy(Water;P=P[2],h=h[2])
T[2]=T(Water;P=P[2],h=h[2])
"Turbine analysis"
h[3]=h(Water;T=T[3],P=P[3])
s[3]=Entropy(Water;T=T[3],P=P[3])
s_s[4]=s[3]
hs[4]=h(s=s_s[4],P=P[4])
Ts[4]=T(s=s_s[4],P=P[4])
W_t=h[3]-hs[4] "Turbine work"
Eta_t=(h[3]-h[4])/(h[3]-hs[4]) "Definition of turbine efficiency"
T[4]=T(P=P[4],h=h[4])
s[4]=s(h=h[4],P=P[4])
x[4]=x(h=h[4],P=P[4])
h[4] = h[3] - W_t "SSSF First Law for the turbine"
x4s$=x4$(x[4])
"Boiler analysis"
Q_in = h[3]-h[2] "SSSF First Law for the Boiler"
"Condenser analysis"
Q_out = h[4]-h[1] "SSSF First Law for the Condenser"
"Cycle Statistics"
W_net=W_t-W_p
Eta_th=W_net/Q_in

Solve