Chapter 1: Thermodynamic Definitions and Concepts

Exa 1.1

In [1]:
#Determine the specific volume for steam of 60% quality at 425 F using 
#(a) Eq 1.3 (b) 1.4 (c) 1.5
import math
#initialisation of variables
Vf= 0.019014 									#ft^3/lbm
Vg= 1.4249 										#ft^3/lbm
T= 425. 										#fahrenheit
quality= 60. 									#%
#CALCULATIONS
Vfg= Vg-Vf 										#Specific volume 
V= (quality/100.)*Vg+(1-(quality/100.))*Vf 		#Volume using 1.3
V1= Vf+(quality/100.)*Vfg  						#Volume using 1.4
V2= Vg-(1-(quality/100.))*Vfg 					#Volume using 1.5
#RESULTS
print '%s %.4f' % ('Vfg (ft^3/lbm) = ',Vfg)
print '%s %.4f' % (' \n V (ft^3/lbm) = ',V)
print '%s %.4f' % (' \n V (ft^3/lbm) = ',V1)
print '%s %.4f' % (' \n V (ft^3/lbm) = ',V2)
raw_input('press enter key to exit')
Vfg (ft^3/lbm) =  1.4059
 
 V (ft^3/lbm) =  0.8625
 
 V (ft^3/lbm) =  0.8625
 
 V (ft^3/lbm) =  0.8625
press enter key to exit
Out[1]:
''

Exa 1.2

In [ ]:
#Saturated steam at 350 lbf/in^2 is heated to 500F. sketch a temperature-
#-volume vapor dome and show the specific volume , temperature and pressure
#for the saturated and superheated states
#initialization of variables
tsat=431.82 					#F
vf=0.019124 					#ft^3/lbm
vg=1.3267 						#ft^3/lbm
#Calculations
print '%s' %('From keenan and keyes steam tables, at 500 f and 350 psia,')
v=1.4913 						#ft^3/lbm
#Results
print '%s %.4f' %('\n Specific volume (ft^3/lbm) = ',v)
raw_input('press enter key to exit')
From keenan and keyes steam tables, at 500 f and 350 psia,

 Specific volume (ft^3/lbm) =  1.4913

Exa 1.3

In [ ]:
#If saturated liquid steam at 100C has its pressure increased to 200 bar 
#while the temperature remains constant, determine how much the liquid
#is compressed.
import math
#initialisation of variables
T= 100. 				#degrees
P= 200. 				#bar
#CALCULATIONS
print '%s' %('From keenan and keyes steam tables')
Psat= 1.0135 			#bar
Vf= 1.0435 				#cm^3/gm
V= 1.0337 				#cm^3/gm
v= Vf-V 				#Amount of compressed
#RESULTS
print '%s %.4f' % ('Amount of liquid compressed (cm^3/gm) = ',v)
raw_input('press enter key to exit')
From keenan and keyes steam tables
Amount of liquid compressed (cm^3/gm) =  0.0098