Chapter 10: Combustion Processes

Exa 10.1

In [1]:
#If 3 mol carbon are completely burned in a process, determine 
#(a) the number of moles of O2 required and
#(b) the mass of O2 required
#initialisation of variables
n= 3 				#lbm mol
Mo2= 32 			#lbm/lbm mol
#CALCULATIONS
m= n*Mo2 			#Mass of O2 required
#RESULTS
print '%s %.2f' % ('Mass of O2 required (lbm) = ',m)
raw_input('press enter key to exit')

Mass of O2 required (lbm) =  96.00
press enter key to exit
Out[1]:
''

Exa 10.3

In [2]:
#Determine the air-fuel ratio on a gram-molal and a mass basis if octane is 
#completely burned in the presence of theoretical air
#initialisation of variables
n= 12.5 					#mol
n1= 3.76 					#mol
M= 114 						#gm/gm mol
M1= 28.96 					#gm/gm mol
#CALCULATIONS
n2= n*(1+n1) 				#Moles
m= n2*M1/M 					#Air-fuel ratio 
#RESULTS
print '%s %.2f' % ('Air-fuel ratio (gm air/gm fuel) = ',m)
raw_input('press enter key to exit')

Air-fuel ratio (gm air/gm fuel) =  15.12
press enter key to exit
Out[2]:
''

Exa 10.4

In [3]:
#Develop the stoichiometric equation that expresses the process of octane 
#being burned with 150% theoretical air. What is the air-fuel ratio on a 
#kilogram molal basis?
#initialisation of variables
p= 150
nO2= 12.5 								#mol
n1= 3.76
#CALCULATIONS
n2= (nO2*(p/100.))+(nO2*n1*(p/100.))	#ir-fuel ratio 
#RESULTS
print '%s %.2f' % ('Air-fuel ratio (kg mol air/kg mol fuel) = ',n2)
raw_input('press enter key to exit')

Air-fuel ratio (kg mol air/kg mol fuel) =  89.25
press enter key to exit
Out[3]:
''

Exa 10.5

In [4]:
#Benzene is used in a heating process that is 65% efficient. How much benzene
#is required to heat  185 liter tank of water from 10 to 30C?
#initialisation of variables
P= 65 
T= 30 				#C
T1= 10 				#C
c= 4.19 			#J/gm C
h= 41961
m= 185 				#lt
#CALCULATIONS
Q= m*1000*c*(T-T1)	#Heat required
M= (Q*100.)/(h*P) 	#Mass of benzene required
#RESULTS
print '%s %.2f' % ('Benzene required (gm) = ',M)
raw_input('press enter key to exit')

Benzene required (gm) =  568.40
press enter key to exit
Out[4]:
''