initial commit / add all books

24 files changed, 522 insertions, 0 deletions

diff --git a/3685/CH12/EX12.1/Ex12_1.sce b/3685/CH12/EX12.1/Ex12_1.sce
new file mode 100644
index 000000000..5cad8cd3f
--- /dev/null
+++ b/3685/CH12/EX12.1/Ex12_1.sce
@@ -0,0 +1,19 @@
+clc

+// Part (a)

+P1 = 1 // Initial pressure in bar

+P2 = 10 // Final pressure in bar

+vf = 0.001043 // specific volume of liquid in m^3/kg

+Wrev = vf*(P1-P2)*1e5 // Work done

+

+printf("\n Example 12.1")

+printf("\n The work required in saturated liquid form is %f kJ/kg",Wrev/1000)

+//The answers vary due to round off error

+

+// Part (b)

+h1 = 2675.5 // Enthalpy at state 1 in kJ/kg

+s1 = 7.3594 // Entropy at state 1 kJ/kgK

+s2 = s1 // Isentropic process

+h2 = 3195.5 // Enthalpy at state 2 kJ/kg

+Wrev1 = h1-h2 // Work done

+printf("\n The work required in saturated vapor form is %d kJ/kg",Wrev1)

+

diff --git a/3685/CH12/EX12.1/Ex12_1.txt b/3685/CH12/EX12.1/Ex12_1.txt
new file mode 100644
index 000000000..f4d1ccad8
--- /dev/null
+++ b/3685/CH12/EX12.1/Ex12_1.txt
@@ -0,0 +1,4 @@
+  

+ Example 12.1

+ The work required in saturated liquid form is -0.938700 kJ/kg

+ The work required in saturated vapor form is -520 kJ/kg
\ No newline at end of file
diff --git a/3685/CH12/EX12.10/Ex12_10.sce b/3685/CH12/EX12.10/Ex12_10.sce
new file mode 100644
index 000000000..1af5bd7c9
--- /dev/null
+++ b/3685/CH12/EX12.10/Ex12_10.sce
@@ -0,0 +1,27 @@
+clc
+h1 = 3037.3 // Enthalpy at state 1 in kJ/kg
+x = 0.96 // Steam quality
+h2 = 561+(x*2163.8) // Enthalpy at state 2 
+s2 = 1.6718+(x*5.3201)// Entropy at state 2 
+s3s = s2 // Isentropic process
+x3s = (s3s-0.6493)/7.5009 // Quality at state 3s 
+h3s = 191.83+(x3s*2392.8) // Enthalpy at state 3s 
+h23 = 0.8*(h2-h3s) // Enthalpy change in process 23
+h3 = h2-h23 // Enthalpy at state 3
+h5 = 561.47  // Enthalpy at state 5
+h4 = 191.83// Enthalpy at state 4
+Qh = 3500 // Heat addition in kJ/s
+w = Qh/(h2-h5) // mass flow rate
+Wt = 1500 // Turbine work
+ws = (Wt+w*(h2-h3))/(h1-h3) // Steam flow rate 
+ws_ = 3600*ws  // Steam flow rate  in kg/h
+h6 = ((ws-w)*h4+w*h5)/ws  //Enthalpy at state 6
+h7 = h6// Enthalpy at state 7
+n_boiler = 0.85 // Boiler efficiency
+CV = 44000 // Calorific value of fuel in kJ/kg
+wf = (1.1*ws_*(h1-h7))/(n_boiler*CV) // Fuel consumption rate
+
+printf("\n Example 12.10\n")
+printf("\n Fuel burning rate is %f tonnes/day",wf*24/1000)
+//The answers vary due to round off error
+
diff --git a/3685/CH12/EX12.10/Ex12_10.txt b/3685/CH12/EX12.10/Ex12_10.txt
new file mode 100644
index 000000000..f102c6dae
--- /dev/null
+++ b/3685/CH12/EX12.10/Ex12_10.txt
@@ -0,0 +1,4 @@
+ 

+ Example 12.10

+

+ Fuel burning rate is 18.159248 tonnes/day 
\ No newline at end of file
diff --git a/3685/CH12/EX12.11/Ex12_11.sce b/3685/CH12/EX12.11/Ex12_11.sce
new file mode 100644
index 000000000..cf52a8438
--- /dev/null
+++ b/3685/CH12/EX12.11/Ex12_11.sce
@@ -0,0 +1,24 @@
+clc
+h1 = 3285  // Enthalpy at state 1 in kJ/kg
+h2s = 3010 // Enthalpy at state 2s in kJ/kg
+h3 = 3280 // // Enthalpy at state 3 in kJ/kg
+h4s = 3030 // // Enthalpy at state 4s in kJ/kg
+// Saturation pressure at temperature 180 degree centigrade
+psat = 10 // In bar
+h4 = h3-0.83*(h3-h4s) // // Enthalpy at state 4 
+h5s = 2225 // // Enthalpy at state 5s in kJ/kg
+h5 = h4-0.83*(h4-h5s) // // Enthalpy at state 5
+h6 = 162.7 // Enthalpy at state 6 in kJ/kg
+h7 = h6 // // Enthalpy at state 7 
+h8 = 762.81// Enthalpy at state 8 in kJ/kg
+h2 = h1-0.785*(h1-h2s) //Enthalpy at state 2 
+m = (h8-h7)/(h4-h7) // regenerative mass flow
+n_cycle = ((h1-h2)+(h3-h4)+(1-m)*(h4-h5))/((h1-h8)+(h3-h2)) // Cycle efficiency
+
+printf("\n Example 12.11\n")
+printf("\n The minimum pressure at which bleeding is neccessary is %d bar",psat)
+printf("\n Steam flow at turbine inlet is %f kg/s",m)
+printf("\n Cycle efficiency is %f percent",n_cycle*100)
+//The answers vary due to round off error
+// Part A and Part B are theoretical problems
+
diff --git a/3685/CH12/EX12.11/Ex12_11.txt b/3685/CH12/EX12.11/Ex12_11.txt
new file mode 100644
index 000000000..2a7867ee8
--- /dev/null
+++ b/3685/CH12/EX12.11/Ex12_11.txt
@@ -0,0 +1,6 @@
+ 

+ Example 12.11

+

+ The minimum pressure at which bleeding is neccessary is 10 bar

+ Steam flow at turbine inlet is 0.206238 kg/s

+ Cycle efficiency is 35.920381 percent 
\ No newline at end of file
diff --git a/3685/CH12/EX12.12/Ex12_12.sce b/3685/CH12/EX12.12/Ex12_12.sce
new file mode 100644
index 000000000..473dabb72
--- /dev/null
+++ b/3685/CH12/EX12.12/Ex12_12.sce
@@ -0,0 +1,39 @@
+clc

+// From table 

+h1 = 2792.2 // Enthalpy at state 1 in kJ/kg 

+h4 = 122.96// Enthalpy at state 4 in kJ/kg 

+hb = 254.88 // Enthalpy at state b in kJ/kg 

+hc = 29.98// Enthalpy at state c in kJ/kg 

+ha = 355.98 // Enthalpy at state a in kJ/kg 

+hd = hc // Isenthalpic process

+h2 = 1949.27 // // Enthalpy at state 2 in kJ/kg 

+//

+m = (h1-h4)/(hb-hc) // Amount of mercury circulating

+Q1t = m*(ha-hd) // Heat addition

+W1t = m*(ha-hb) + (h1-h2) // Turbine work

+n = W1t/Q1t // first law efficiency

+

+printf("\n Example 12.12 \n")

+printf("\n Overall efficiency of the cycle is %f percent",n*100)

+//The answers vary due to round off error

+

+S = 50000 // Stem flow rate through turbine in kg/h

+wm = S*m // mercury flow rate

+printf("\n Flow through the mercury turbine is %e kg/h",wm)

+

+Wt = W1t*S/3600 // Turbine work

+printf("\n Useful work done in binary vapor cycle is %f MW",Wt/1e3)

+nm = 0.85 // Internal efficiency of mercury turbine

+ns = 0.87 // Internal efficiency of steam turbine

+WTm = nm*(ha-hb) // turbine work of mercury based cycle

+hb_ = ha-WTm // Enthalpy at state b in kJ/kg

+m_ = (h1-h4)/(hb_-hc) // mass flow rate of mercury

+h1_ = 3037.3 // Enthalpy at state 1 in kJ/kg

+Q1t = m_*(ha-hd)+(h1_-h1) // Heat addition

+x2_ = (6.9160-0.4226)/(8.47-0.4226) // steam quality

+h2_ = 121+(0.806*2432.9) // Enthalpy at state 2 in kJ/kg 

+WTst = ns*(h1_-h2_) // Turbine work

+WTt = m_*(ha-hb_)+WTst // Total turbine work

+N = WTt/Q1t //Overall efficiency 

+printf("\n Overall efficiency is %f percent",N*100)

+// The answers vary due to round off error

diff --git a/3685/CH12/EX12.12/Ex12_12.txt b/3685/CH12/EX12.12/Ex12_12.txt
new file mode 100644
index 000000000..07364e9fe
--- /dev/null
+++ b/3685/CH12/EX12.12/Ex12_12.txt
@@ -0,0 +1,7 @@
+ 

+ Example 12.12 

+

+ Overall efficiency of the cycle is 52.798182 percent

+ Flow through the mercury turbine is 5.934282e+05 kg/h

+ Useful work done in binary vapor cycle is 28.372803 MW

+ Overall efficiency is 46.169369 percent 
\ No newline at end of file
diff --git a/3685/CH12/EX12.2/Ex12_2.sce b/3685/CH12/EX12.2/Ex12_2.sce
new file mode 100644
index 000000000..dffe2e34b
--- /dev/null
+++ b/3685/CH12/EX12.2/Ex12_2.sce
@@ -0,0 +1,41 @@
+clc

+h1 = 3159.3 // Enthalpy at state 1 in kJ/kg

+s1 = 6.9917 // Entropy at state 1 in kJ/kgK

+h3 = 173.88  // Enthalpy at state 3 in kJ/kg

+s3 = 0.5926 // Entropy at state 3 in kJ/kgK

+sfp2 = s3 // Isentropic process

+hfp2 = h3 // Isenthalpic process

+hfgp2 = 2403.1 // Latent heat of vaporization in kJ/kg

+sgp2 = 8.2287 // Entropy of gas in kJ/kgK

+vfp2 = 0.001008 // Specific volume in m^3/kg

+sfgp2 = 7.6361// Entropy of liquid in kJ/kgK

+x2s = (s1-sfp2)/(sfgp2)// Steam quality

+h2s = hfp2+(x2s*hfgp2) // Enthalpy at state 2s

+// Part (a)

+P1 = 20 // Turbine inlet pressure in bar

+P2 = 0.08 // Turbine exit pressure in bar

+h4s = vfp2*(P1-P2)*1e2+h3  // Enthalpy at state 4s

+Wp = h4s-h3 // Pump work

+Wt = h1-h2s // Turbine work

+Wnet = Wt-Wp // Net work 

+Q1 = h1-h4s // Heat addition

+n_cycle = Wnet/Q1// Cycle efficiency

+printf("\n Example 12.2")

+printf("\n Net work per kg of steam is %f kJ/kg",Wnet)//The answer provided in the textbook is wrong

+

+printf("\n Cycle efficiency is %f percent",n_cycle*100)

+

+// Part (b)

+n_p = 0.8 // pump efficiency

+n_t = 0.8// Turbine efficiency

+Wp_ = Wp/n_p // Pump work

+Wt_ = Wt*n_t // Turbine work

+Wnet_ = Wt_-Wp_// Net work

+P = 100*((Wnet-Wnet_)/Wnet) // Percentage reduction in net work

+n_cycle_ = Wnet_/Q1 // cycle efficiency

+P_ = 100*((n_cycle-n_cycle_)/n_cycle) //reduction in cycle

+printf("\n\n Percentage reduction in net work per kg of steam is %f percent",P)

+printf("\n Percentage reduction in cycle efficiency is %f percent",P_)

+

+//The answers vary due to round off error

+

diff --git a/3685/CH12/EX12.2/Ex12_2.txt b/3685/CH12/EX12.2/Ex12_2.txt
new file mode 100644
index 000000000..82943e493
--- /dev/null
+++ b/3685/CH12/EX12.2/Ex12_2.txt
@@ -0,0 +1,7 @@
+ 

+ Example 12.2

+ Net work per kg of steam is 969.599095 kJ/kg

+ Cycle efficiency is 32.499671 percent

+

+ Percentage reduction in net work per kg of steam is 20.093190 percent

+ Percentage reduction in cycle efficiency is 20.093190 percent 
\ No newline at end of file
diff --git a/3685/CH12/EX12.3/Ex12_3.sce b/3685/CH12/EX12.3/Ex12_3.sce
new file mode 100644
index 000000000..74122fb5f
--- /dev/null
+++ b/3685/CH12/EX12.3/Ex12_3.sce
@@ -0,0 +1,27 @@
+clc

+P1 = 0.08 // Exhaust pressure in bar

+sf = 0.5926 // Entropy of fluid in kJ/kgK

+x2s = 0.85 // Steam quality

+sg = 8.2287 // Entropy of gas in kJ/kgK

+s2s = sf+(x2s*(sg-sf)) // Entropy of mixture at state 2s in kJ/kgK

+s1 = s2s // Isentropic process

+P2 = 16.832 // by steam table opposite to s1 in bar

+h1 = 3165.54 // Enthalpy at state 1 in kJ/kg

+h2s = 173.88 + (0.85*2403.1) // Enthalpy at state 2s in kJ/kg

+h3 = 173.88// Enthalpy at state 3 in kJ/kg

+vfp2 = 0.001 // specific volume of liquid in m^3/kg

+h4s = h3 + (vfp2*(P2-P1)*100)// Enthalpy at state 4s in kJ/kg

+Q1 = h1-h4s // Heat addition

+Wt = h1-h2s // Turbine work

+Wp = h4s-h3 // Pump work

+n_cycle = 100*((Wt-Wp)/Q1) // Cycle efficiency

+Tm = (h1-h4s)/(s2s-sf) // Mean temperature of heat addition

+

+printf("\n Example 12.3")

+printf("\n The greatest allowable steam pressure at the turbine inlet is %f bar",P2)

+

+printf("\n Rankine cycle efficiency is %f percent",n_cycle)

+

+printf("\n Mean temperature of heat addition is %f degree celcius",Tm-273)

+//The answers vary due to round off error

+

diff --git a/3685/CH12/EX12.3/Ex12_3.txt b/3685/CH12/EX12.3/Ex12_3.txt
new file mode 100644
index 000000000..148ad9819
--- /dev/null
+++ b/3685/CH12/EX12.3/Ex12_3.txt
@@ -0,0 +1,5 @@
+ 

+ Example 12.3

+ The greatest allowable steam pressure at the turbine inlet is 16.832000 bar

+ Rankine cycle efficiency is 31.684101 percent

+ Mean temperature of heat addition is 187.657820 degree celcius 
\ No newline at end of file
diff --git a/3685/CH12/EX12.4/Ex12_4.sce b/3685/CH12/EX12.4/Ex12_4.sce
new file mode 100644
index 000000000..e86cedf09
--- /dev/null
+++ b/3685/CH12/EX12.4/Ex12_4.sce
@@ -0,0 +1,22 @@
+clc

+h1 = 3465 // Enthalpy at state 1 in kJ/kgK

+h2s = 3065 //Enthalpy at state 2s in kJ/kgK 

+h3 = 3565 //Enthalpy at state 3 in kJ/kgK

+h4s = 2300 // Enthalpy at state 4s in kJ/kgK

+x4s = 0.88 // Steam quality at state 4s

+h5 = 191.83// Enthalpy at state 5 in kJ/kgK

+v = 0.001 // specific volume in m^3/kg

+P = 150 // Boiler outlet pressure in bar

+Wp = v*P*100 // Pump work

+h6s = 206.83 // Enthalpy at state 6s in kJ/kgK

+Q1 = (h1-h6s)+(h3-h2s) // Heat addition

+Wt = (h1-h2s)+(h3-h4s) // Turbine work

+Wnet = Wt-Wp // Net work

+n_cycle = 100*Wnet/Q1 // cycle efficiency

+sr = 3600/Wnet //Steam rate

+

+printf("\n Example 12.4 \n")

+printf("\n Quality at turbine exhaust is %f ",0.88)

+printf("\n Cycle efficiency is %f percent",n_cycle)

+printf("\n Steam rate is %f kg/kW h",sr)

+//The answers vary due to round off error

diff --git a/3685/CH12/EX12.4/Ex12_4.txt b/3685/CH12/EX12.4/Ex12_4.txt
new file mode 100644
index 000000000..edb7fc5b3
--- /dev/null
+++ b/3685/CH12/EX12.4/Ex12_4.txt
@@ -0,0 +1,6 @@
+ 

+ Example 12.4 

+

+ Quality at turbine exhaust is 0.880000 

+ Cycle efficiency is 43.904347 percent

+ Steam rate is 2.181818 kg/kW h 
\ No newline at end of file
diff --git a/3685/CH12/EX12.5/Ex12_5.sce b/3685/CH12/EX12.5/Ex12_5.sce
new file mode 100644
index 000000000..4ab781ca9
--- /dev/null
+++ b/3685/CH12/EX12.5/Ex12_5.sce
@@ -0,0 +1,40 @@
+clc

+h1 = 3230.9 // Enthalpy at state 1 in kJ/kg

+s1 = 6.9212 // Entropy at state 1 in kJ/kgK

+s2 = s1 // Isentropic process

+s3 = s1 // Isentropic process

+h2 = 2796  // Enthalpy at state 2 in kJ/kg

+sf = 0.6493 // ENtropy of fluid onkJ/kgK

+sfg = 7.5009 // Entropy change due to vaporization

+x3 = (s3-sf)/sfg // steam quality

+h3 = 191.83 + x3*2392.8 // Enthalpy at state 3

+h4 = 191.83 // Enthalpy at state 4 in kJ/kg

+h5 = h4 // Isenthalpic process

+h6 = 640.23 // Enthalpy at state 6 in kJ/kg

+h7 = h6 // Isenthalpic process

+m = (h6-h5)/(h2-h5) // regenerative mass

+Wt = (h1-h2)+(1-m)*(h2-h3) // turbine work

+Q1 = h1-h6 // Heat addition

+n_cycle = 100*Wt/Q1 // Cycle efficiency

+sr = 3600/Wt // Steam rate

+s7 = 1.8607  // Entropy at state 7 in kJ/kgK

+s4 = 0.6493 // Entropy at state 4 in kJ/kgK 

+Tm = (h1-h7)/(s1-s7) // Mean temperature of heat addition with regeneration

+Tm1 = (h1-h4)/(s1-s4) // Mean temperature of heat addition without regeneration

+dT = Tm-Tm1 // Change in temperature

+Wt_ = h1-h3 // Turbine work

+sr_ = 3600/Wt_ // Steam rate

+dsr = sr-sr_// Change in steam rate

+n_cycle_ = 100*(h1-h3)/(h1-h4) // Cycle effciency

+dn = n_cycle-n_cycle_// Change in efficiency

+printf("\n Example 12.5\n")

+printf("\n Efficiency of the cycle is %f percent",n_cycle)

+

+printf("\n Steam rate of the cycle is %f kg/kW h",sr)//The answer provided in the textbook is wrong

+

+printf("\n Increase in temperature due to regeneration is %f degree centigrade",dT)

+printf("\n Increase in steam rate due to regeneration is %f kg/kW h",dsr)//The answer provided in the textbook is wrong

+

+printf("\n Increase in Efficiency of the cycle due to regeneration is %f percent",dn)

+

+//The answers vary due to round off error

diff --git a/3685/CH12/EX12.5/Ex12_5.txt b/3685/CH12/EX12.5/Ex12_5.txt
new file mode 100644
index 000000000..4bf4467b4
--- /dev/null
+++ b/3685/CH12/EX12.5/Ex12_5.txt
@@ -0,0 +1,8 @@
+ 

+ Example 12.5

+

+ Efficiency of the cycle is 36.068757 percent

+ Steam rate of the cycle is 3.852647 kg/kW h

+ Increase in temperature due to regeneration is 27.386207 degree centigrade

+ Increase in steam rate due to regeneration is 0.385518 kg/kW h

+ Increase in Efficiency of the cycle due to regeneration is 1.902940 percent
\ No newline at end of file
diff --git a/3685/CH12/EX12.6/Ex12_6.sce b/3685/CH12/EX12.6/Ex12_6.sce
new file mode 100644
index 000000000..4aaa681d3
--- /dev/null
+++ b/3685/CH12/EX12.6/Ex12_6.sce
@@ -0,0 +1,55 @@
+clc
+h1 = 3023.5  // Enthalpy of steam at state 1 in kJ/kg
+s1 = 6.7664 // Enthalpy of steam at state 1 in kJ/kgK
+s2 = s1 // Isentropic process
+s3 = s1 //Isentropic process
+s4 = s1 //Isentropic process
+t_sat_20 = 212 // Saturation temperature at 20 bar in degree Celsius
+t_sat_1 = 46 // Saturation temperature at 1 bar in degree Celsius
+dt = t_sat_20-t_sat_1 // Change in temperature
+n =3 // number of heaters
+t = dt/n // temperature rise per heater
+t1 = t_sat_20-t // Operational temperature of first heater
+t2 = t1-t// Operational temperature of second heater
+// 0.1 bar
+hf = 191.83 // Enthalpy of fluid in kJ/kg
+hfg = 2392.8 // Latent heat of vaporization in kJ/kg
+sf = 0.6493// Entropy of fluid in kJ/kgK
+sg = 8.1502// Entropy of gas in kJ/kgK
+// At 100 degree
+hf100 = 419.04 // Enthalpy of fluid in kJ/kg  
+hfg100 = 2257.0// Latent heat of vaporization in kJ/kg 
+sf100 = 1.3069 // Entropy of fluid in kJ/kgK 
+sg100 = 7.3549 // Entropy of gas in kJ/kgK
+// At 150 degree
+hf150 = 632.20 // Enthalpy of fluid in kJ/kg  
+hfg150 = 2114.3// Latent heat of vaporization in kJ/kg  
+sf150 = 1.8418 // Entropy of fluid in kJ/kgK 
+sg150 = 6.8379// Entropy of gas in kJ/kgK
+x2 = (s1-sf150)/4.9961 // Steam quality
+h2 = hf150+(x2*hfg150) // Enthalpy at state 2 in kJ/kg
+x3 = (s1-sf100)/6.0480 // Steam quality
+h3 = hf100+(x3*hfg100) // Enthalpy at state 3 in kJ/kg 
+x4 = (s1-sf)/7.5010 // Steam quality
+h4 = hf+(x4*hfg)//Enthalpy at state 4 in kJ/kg
+h5 = hf // Enthalpy at state 5 in kJ/kg
+h6 = h5 //Enthalpy at state 6 in kJ/kg
+h7 = hf100 // Enthalpy at state 7 in kJ/kg
+h8 = h7 // Enthalpy at state 8 in kJ/kg
+h9 = 632.2  // Enthalpy at state 9 in kJ/kg
+h10 = h9 // Enthalpy at state 10 in kJ/kg
+m1 = (h9-h7)/(h2-h7) // regenerative mass 
+m2 = ((1-m1)*(h7-h6))/(h3-h6) // regenerative mass
+Wt = 1*(h1-h2)+(1-m1)*(h2-h3)+(1-m1-m2)*(h3-h4) // Turbine work
+Q1 = h1-h9 // Heat addition
+Wp = 0  // Pump work is neglected
+n_cycle = 100*(Wt-Wp)/Q1 // Cycle efficiency
+sr = 3600/(Wt-Wp)  // Steam rate
+
+printf("\n Example 12.6\n")
+printf("\n Steam quality at turbine exhaust is %f ",x3)
+printf("\n Net work per kg of stem is %f kJ/kg",Wt)
+printf("\n Cycle efficiency is %f percent",n_cycle)
+printf("\n Stream rate is %f kg/kW h",sr)
+//The answers vary due to round off error
+
diff --git a/3685/CH12/EX12.6/Ex12_6.txt b/3685/CH12/EX12.6/Ex12_6.txt
new file mode 100644
index 000000000..71a135007
--- /dev/null
+++ b/3685/CH12/EX12.6/Ex12_6.txt
@@ -0,0 +1,7 @@
+ 

+ Example 12.6

+

+ Steam quality at turbine exhaust is 0.902695 

+ Net work per kg of stem is 798.641702 kJ/kg

+ Cycle efficiency is 33.397805 percent

+ Stream rate is 4.507653 kg/kW h
\ No newline at end of file
diff --git a/3685/CH12/EX12.7/Ex12_7.sce b/3685/CH12/EX12.7/Ex12_7.sce
new file mode 100644
index 000000000..a12c3be96
--- /dev/null
+++ b/3685/CH12/EX12.7/Ex12_7.sce
@@ -0,0 +1,34 @@
+clc
+Ti = 2000 // Hot gas inlet temperature in K
+Te = 450 // Hot gas exhaust temperature in K
+T0 = 300 // Ambient temperature in K
+Q1_dot = 100 // Heating rate provided by steam in kW
+cpg = 1.1 // Heat capacity of gas in kJ/kg
+wg = Q1_dot/(cpg*(Ti-Te)) // mass flow rate of hot gas
+af1 = wg*cpg*T0*((Ti/T0)-1-log(Ti/T0)) // Availability at inlet
+af2 = wg*cpg*T0*((Te/T0)-1-log(Te/T0)) // Availability at exit
+afi = af1-af2 // Change in availability
+h1 = 2801 // Enthalpy at state 1 in kJ/kg
+h3 = 169 //Enthalpy at state 3 in kJ/kg
+h4 = 172.8 //Enthalpy at state 4 in kJ/kg
+h2 = 1890.2 // Enthalpy at state 2 in kJ/kg
+s1 = 6.068 // Entropy at state 1 in kJ/kgK
+s2 = s1 // Isentropic process
+s3 = 0.576 // Entropy at state 3 in kJ/kgK
+s4 = s3 // Isentropic process
+Wt = h1-h2 // Turbine work
+Wp = h4-h3 // Pump work
+Q1 = h1-h4 // Heat addition
+Q2 = h2-h3// Heat rejection
+Wnet = Wt-Wp // Net work
+ws = Q1_dot/2628 // steam mass flow rate
+afu = 38*(h1-h4-T0*(s1-s3)) // availability loss
+I_dot = afi-afu // Rate of exergy destruction
+Wnet_dot = ws*Wnet// Mechanical power rate
+afc = ws*(h2-h3-T0*(s2-s3)) // Exergy flow rate of of wet steam
+n2 = 100*Wnet_dot/af1 // second law efficiency
+
+printf("\n Example 12.7\n")
+printf("\n The second law efficiency is %f percent",n2)
+//The answers vary due to round off error
+
diff --git a/3685/CH12/EX12.7/Ex12_7.txt b/3685/CH12/EX12.7/Ex12_7.txt
new file mode 100644
index 000000000..e1d668ec3
--- /dev/null
+++ b/3685/CH12/EX12.7/Ex12_7.txt
@@ -0,0 +1,4 @@
+ 

+ Example 12.7

+

+ The second law efficiency is 47.304586 percent 
\ No newline at end of file
diff --git a/3685/CH12/EX12.8/Ex12_8.sce b/3685/CH12/EX12.8/Ex12_8.sce
new file mode 100644
index 000000000..60add7144
--- /dev/null
+++ b/3685/CH12/EX12.8/Ex12_8.sce
@@ -0,0 +1,83 @@
+clc
+// Part (a)
+h1 = 2758 // Enthalpy at state 1 in kJ/kg
+h2 = 1817 // Enthalpy at state 2 in kJ/kg
+h3 = 192 // Enthalpy at state 3 in kJ/kg
+h4 = 200// Enthalpy at state 4 in kJ/kg
+Wt = h1-h2 // turbine work
+Wp = h4-h3 // Pump work
+Q1 = h1-h4 // Heat addition
+Wnet = Wt-Wp // Net work doen
+n1 = Wnet/Q1 // First law efficiency
+WR = Wnet/Wt // Work ratio
+Q1_ = 100 // Heat addition rate in MW
+PO = n1*Q1_ // power output
+cpg = 1000 // Specific heat capacity in J/kg
+wg = (Q1_/(833-450)) // mass flow rate of gas
+EIR = wg*cpg*((833-300)-300*(log(833/300)))/1000 // Exergy input
+n2 = PO/EIR // Second law efficiency
+
+printf("\n Example 12.8\n")
+printf("\n Part (a)")
+printf("\n The first law efficiency n1 is %f",n1*100)
+printf("\n The second law efficiency n2 is %f",n2*100)
+printf("\n The work ratio is %f",WR)
+// Part (b)
+h1b = 3398 // Enthalpy at state 1 in kJ/kg
+h2b = 2130 // Enthalpy at state 2 in kJ/kg
+h3b = 192 // Enthalpy at state 3 in kJ/kg
+h4b = 200// Enthalpy at state 4 in kJ/kg
+Wtb = 1268 // turbine work in kJ/kg
+Wpb = 8  // Pump work in kJ/kg
+Q1b = 3198// Heat addition rate in kW
+n1b = (Wtb-Wpb)/Q1b //first law efficiency
+WRb = (Wtb-Wpb)/Wtb // WOrk ratio
+EIRb = 59.3 // Exergy input rate in MW
+Wnetb = Q1_*n1b // net work done
+
+n2b = Wnetb/EIRb // Second law efficiency
+printf("\n Part (b)") 
+printf("\n The first law efficiency n1 is %f",n1b*100)
+printf("\n The second law efficiency n2 is %f",n2b*100)
+printf("\n The work ration is %f",WRb)
+
+// Part (c)
+h1c = 3398 // Enthalpy at state 1 in kJ/kg
+h2c = 2761 // Enthalpy at state 2 in kJ/kg
+h3c = 3482 // Enthalpy at state 3 in kJ/kg
+h4c = 2522 // Enthalpy at state 4 in kJ/kg
+h5c = 192 // Enthalpy at state 5 in kJ/kg
+h6c = 200// Enthalpy at state 6 in kJ/kg
+Wt1 = 637 // Turbine work in kJ/kg
+Wt2 = 960 // Turbine work in kJ/kg
+Wtc = Wt1+Wt2  // Net turbine work in kJ/kg
+Wp = 8 // Pump work in kJ/kg 
+Wnetc = Wtc-Wp // net work done 
+Q1c = 3198+721 // Heat addition
+n1c = Wnetc/Q1c// First law efficiency
+WRc = Wnetc/Wtc// Work ratio
+POc = Q1_*n1c// Power output
+EIRc = 59.3// Exergy input in MW
+n2c = POc/EIRc // Second law efficiency
+printf("\n Part (c)")
+printf("\n The first law efficiency n1 is %f",n1c*100)
+printf("\n The second law efficiency n2 is %f",n2c*100)
+printf("\n The work ration is %f",WRc)
+
+// Part (d)
+T3 = 45.8 // saturation temperature at 0.1 bar in degree celsius 
+T1 = 295 // saturation temperature at 80 bar in degree celsius 
+n1d = 1-((T3+273)/(T1+273)) // First law efficiency
+Q1d = 2758-1316 // Heat addition
+Wnet = Q1d*n1d // Net work output
+Wpd = 8 // Pump work in kJ/kg
+Wtd = 641// Turbine work in kJ/kg
+WRd = (Wt-Wp)/Wt // Work ratio
+POd = Q1_*0.439// Power output
+EIRd = (Q1_/(833-593))*cpg*((833-300)-300*(log(833/300)))/1000 //Exergy Input rate in MW
+n2d = POd/EIRd // Second law efficiency
+printf("\n Part (d)")
+printf("\n The first law efficiency n1 is %f",n1d*100)
+printf("\n The second law efficiency n2 is %f",n2d*100)
+printf("\n The work ration is %f",WRd)
+//The answers vary due to round off error
diff --git a/3685/CH12/EX12.8/Ex12_8.txt b/3685/CH12/EX12.8/Ex12_8.txt
new file mode 100644
index 000000000..776e801e3
--- /dev/null
+++ b/3685/CH12/EX12.8/Ex12_8.txt
@@ -0,0 +1,19 @@
+ 

+ Example 12.8

+

+ Part (a)

+ The first law efficiency n1 is 36.473808

+ The second law efficiency n2 is 56.037667

+ The work ratio is 0.991498

+ Part (b)

+ The first law efficiency n1 is 39.399625

+ The second law efficiency n2 is 66.441188

+ The work ration is 0.993691

+ Part (c)

+ The first law efficiency n1 is 40.546058

+ The second law efficiency n2 is 68.374465

+ The work ration is 0.994991

+ Part (d)

+ The first law efficiency n1 is 43.873239

+ The second law efficiency n2 is 42.264519

+ The work ration is 0.991498 
\ No newline at end of file
diff --git a/3685/CH12/EX12.9/Ex12_9.sce b/3685/CH12/EX12.9/Ex12_9.sce
new file mode 100644
index 000000000..9cb3f5d23
--- /dev/null
+++ b/3685/CH12/EX12.9/Ex12_9.sce
@@ -0,0 +1,29 @@
+clc
+hfg = 2202.6 // Latent heat of fusion in kJ/kg
+Qh = 5.83 // Heat addition in MJ/s
+ws = Qh/hfg // steam flow rate
+eg = 0.9 // efficiency of generator
+P = 1000 // Power generation rate in kW
+Wnet = 1000/eg // Net output
+nbrake = 0.8 // brake thermal efficiency
+h1_2s = Wnet/(ws*nbrake) // Ideal heat addition
+n_internal = 0.85 // internal efficiency
+h12 = n_internal*h1_2s // Actual heat addition
+hg = 2706.3 // Enthalpy of gas in kJ/kg
+h2 = hg //Isenthalpic process 
+h1 = h12+h2 // Total enthalpy 
+h2s = h1-h1_2s // Enthalpy change
+hf = 503.71 // Enthalpy of fluid in kJ/kg 
+x2s = (h2s-hf)/hfg // Quality of steam
+sf = 1.5276  // entropy of fluid in kJ/kgK
+sfg = 5.6020 // Entropy change due to vaporization in kJ/kgK
+s2s = sf+(x2s*sfg) // Entropy at state 2s
+s1 = s2s // Isentropic process
+P1 = 22.5 // Turbine inlet pressure in bar from Mollier chart
+t1 = 360 // Temperature of the steam in degree Celsius from Mollier chart
+
+printf("\n Example 12.9\n")
+printf("\n Temperature of the steam is %d degree celcius",t1)
+printf("\n Pressure of the steam is %f bar",P1)
+//The answers vary due to round off error
+
diff --git a/3685/CH12/EX12.9/Ex12_9.txt b/3685/CH12/EX12.9/Ex12_9.txt
new file mode 100644
index 000000000..2482960dd
--- /dev/null
+++ b/3685/CH12/EX12.9/Ex12_9.txt
@@ -0,0 +1,5 @@
+ 

+ Example 12.9

+

+ Temperature of the steam is 360 degree celcius

+ Pressure of the steam is 22.500000 bar
\ No newline at end of file