#calculate heat and efficency
##initialisation of variables
m= 0.35 ##kg
u2= 211.785 ##kJ/kg
u1= 182.267 ##kJ/kg
p2= 300. ##kPa
v3= 0.085566 ##kJ/kg
v2= 0.076218 ##kJ/kg
h3= 260.391 ##kJ/kg
h2= 234.650 ##kJ/kg
u4= 199.460 ##kJ/kg
u3= 234.721 ##kJ/kg
p4= 250.##kPa
v1= 0.076218 ##kJ/kg
v4= 0.085566 ##kJ/kg
h1= 201.322 ##kJ/kg
h4= 220.851 ##kJ/kg
##CALCULATIONS
Q12= m*(u2-u1)
W23= m*p2*(v3-v2)
Q23= m*(h3-h2)
W34= 0.
Q34= m*(u4-u3)
W41= m*p4*(v1-v4)
Q41= m*(h1-h4)
dW= W23+W41
dQ= Q12+Q23+Q34+Q41
Qh= Q12+Q23
n= dW*100./Qh
##RESULTS
print'%s %.2f %s'%('heat = ',Qh,'kj')
print'%s %.2f %s'%('efficiency =',n, 'percent')
import math
#calculate effiecncy of heat engine and efficency
##initialisation of variables
Qc= 9 ##kW
W= 7.5 ##kW
Qh= Qc+W
Tc= 50 ##C
Th= 400 ##C
##CALCULATIONS
n= W/Qh
nrev= 1-((273.15+Tc)/(273.15+Th))
##RESULTS
print'%s %.3f %s'% ('efficiency of heat engine = ',n,'')
print'%s %.3f %s'%('efficiency =',nrev,'')