Mechanical Refrigeration

Example 13.2,Page 596

In [10]:
# Initialization of Variable
from math import pi
from math import atan
from numpy import *
mr=3.0 #lb
mj=5.0 #lb
t2=67.0 #F
t1=60.0 #lb
ihp=7.25
#"From mollier charts"
h4=709 #Btu/b
h3=618 #Btu/lb

#calculations
energyin=ihp*2545/60
energyout=mr*(h4-h3) + mj*(t2-t1)

#results
print "Energy in  Btu/min",round(energyin,3)
print "Energy out  Btu/min",round(energyout,3)

Energy in  Btu/min 307.521
Energy out  Btu/min 308.0

Example 13.3,Page 602

In [11]:
# Initialization of Variable
from math import pi
from math import atan
from numpy import *
r=3.0 #lb
hp=10.0 #hp

#calculations
h3=618 #Btu/lb
h1=131 #Btu/lb
Qe=mr*(h3-h1)
work=hp*2545/60
cop=Qe/work

#results
print "Coefficient of performance ",round(cop,3)

Coefficient of performance  3.444