# Feed Water Heaters and Condensers¶

## Example 11.1,Page 554¶

In [3]:
# Initialization of Variable
from math import pi
from math import atan, cos
from numpy import *
m1=1000.0 #lb/hr
m2=5000.0 #lb/hr
m3=3000.0 #lb/hr
#From mollier charts
h5=196.16 #Btu/lb
h1=38.04 #Btu/lb
h2=67.97 #Btu/lb
h3=117.89 #Btu/lb
h4=1156.3 #Btu/lb

#calculations
m4=(m1*h1+m2*h2+m3*h3-(m1+m2+m3)*h5)/(h5-h4) #mass rate

#results
print "Pounds of steam entering the heater in lb/hr", round(m4,3)

Pounds of steam entering the heater in lb/hr 1076.801


## Example 11.2,Page 558¶

In [4]:
# Initialization of Variable
from math import pi
from math import atan, cos
from numpy import *
P1=100.0 #psia
T1=400.0 #F
T2=70.0 #F
#"From mollier charts"
h1=1227.6 #Btu/lb
h2=298.4 #Btu/lb
h3=279.9 #Btu/lb
h4=38.04 #Btu/lb

#calculations
m1=(h3-h4)/(h1-h2)
#results
print "Mass of steam required in lb steam per lb water",round(m1,3)

Mass of steam required in lb steam per lb water 0.26


## Example 11.3,Page 567¶

In [5]:
# Initialization of Variable
from math import pi
from math import atan, cos
from numpy import *
h0=1260.0 #Btu/lb
msr=15.0 #lb
m4=15.0 #lb per hr per kw
t2=80.0 #F
t3=60.0 #F

#calculations
h1=h0-3413/msr
#"from mollier charts"
h4=58 #Btu/lb
dt=t2-t3
m3=m4*(h1-h4)/dt

#results
print "enthalpy of steam entering the condenser in Btu/lb",round(h1,3)
print " mass of cooling water in lb per hr per kw",round(m3,3)

enthalpy of steam entering the condenser in Btu/lb 1032.467
mass of cooling water in lb per hr per kw 730.85


## Example 11.4,Page 568¶

In [6]:
# Initialization of Variable
from math import pi
from math import atan, cos
from numpy import *
m4=8*1000000 #lb per hr
dt=12 #F

#calculations
#from mollier charts")
dh4=950 #Btu/lb
m3=m4*(dh4)/dt #mass rate

#results
print " mass of cooling water in lb per hr",round(m3,4)

 mass of cooling water in lb per hr 633333333.0