16 files changed, 338 insertions, 0 deletions
diff --git a/2870/CH8/EX8.1/Ex8_1.sce b/2870/CH8/EX8.1/Ex8_1.sce
new file mode 100755
index 000000000..407bb67b2
--- /dev/null
+++ b/2870/CH8/EX8.1/Ex8_1.sce
@@ -0,0 +1,15 @@
+clc;clear;
+// Example 8.1
+
+// given data
+D=12;
+V=10;
+
+// density of air at 25C & 1atm
+p=1.18;
+
+//calculations
+ke=(V^2)/2/1000;//factor of 1000 for converting J into kJ
+m=p*%pi*[D ^2]*V/4; 
+MP=m*(ke);
+disp(MP,'Maximum power in kW')
diff --git a/2870/CH8/EX8.10/Ex8_10.sce b/2870/CH8/EX8.10/Ex8_10.sce
new file mode 100755
index 000000000..688046f2d
--- /dev/null
+++ b/2870/CH8/EX8.10/Ex8_10.sce
@@ -0,0 +1,18 @@
+clc;clear;
+//Example 8.10
+
+//given values
+Q=1035;
+T0=273;
+Tin=293;
+Tout=278;
+T1=300;
+
+//calculations
+//Xin - Xout - Xdestroyed = dX/dt
+Xdestroyed=Q*(1-T0/Tin)-Q*(1-T0/Tout);
+Xdestroyed=round(Xdestroyed);
+disp(Xdestroyed,'the rate of exergy destroyed in W');
+//the total rate of exergy destroyed
+Xdestroyed=Q*(1-T0/T1)-Q*(1-T0/T0);
+disp(Xdestroyed,'the otal total of exergy destroyed in W');
diff --git a/2870/CH8/EX8.11/Ex8_11.sce b/2870/CH8/EX8.11/Ex8_11.sce
new file mode 100755
index 000000000..7497d0ddc
--- /dev/null
+++ b/2870/CH8/EX8.11/Ex8_11.sce
@@ -0,0 +1,37 @@
+clc;clear;
+//Example 8.11
+
+//given data
+m=0.05;
+P1=1000;
+T1=300+273;//in K
+P2=200;
+T2=150+273;//in K
+P0=100;
+T0=25+273;//in K
+Qout=2;
+
+//from Table A-6 & A-4
+u1=2793.7;
+v1=0.25799;
+s1=7.1246;
+u2=2577.1;
+v2=0.95986;
+s2=7.2810;
+u0=104.83;
+v0=0.00103;
+s0=0.3672;
+
+//calculations
+X1=m*(u1-u0-T0*(s1-s0)+P0*(v1-v0));
+X2=m*(u2-u0-T0*(s2-s0)+P0*(v2-v0));
+disp(X1,'exergy of intial state in kJ');
+disp(X2,'exergy of final state in kJ');
+dX=X2-X1;
+disp(dX,'exergy change in system in kJ');
+Wout=-Qout-m*(u2-u1);
+Wu=Wout-P0*m*(v2-v1);
+Xdestroyed=X1-X2-Wu;
+disp(Xdestroyed,'the exergy destroyed in kJ');
+nII=Wu/(X1-X2);
+disp(nII,'second law efficiency of this process')
diff --git a/2870/CH8/EX8.12/Ex8_12.sce b/2870/CH8/EX8.12/Ex8_12.sce
new file mode 100755
index 000000000..b4feb2437
--- /dev/null
+++ b/2870/CH8/EX8.12/Ex8_12.sce
@@ -0,0 +1,19 @@
+clc;clear;
+//Example 8.12
+
+//given data
+m=2;
+T0=70+460;//in R
+P1=20;
+T1=70+460;//in R
+T2=130+460;//in R
+
+//constants used
+Cv=0.172;//in Btu/lbm - F
+
+//calculations
+Xdestroyed=T0*m*Cv*log(T2/T1);
+disp(Xdestroyed,'exergy destroyed in Btu');
+Wrev=integrate('(1-T0/T)*m*Cv','T',T1,T2);
+Wrev=round(Wrev);
+disp(Wrev,'the reversible work in Btu')
diff --git a/2870/CH8/EX8.13/Ex8_13.sce b/2870/CH8/EX8.13/Ex8_13.sce
new file mode 100755
index 000000000..aca921dd7
--- /dev/null
+++ b/2870/CH8/EX8.13/Ex8_13.sce
@@ -0,0 +1,29 @@
+clc;clear;
+//Example 8.13
+
+//given data
+T0=20+273;//in K
+P0=100;
+Tiw=30+273;//in K
+mw=100;
+Tii=350+273;//in K
+mi=5;
+
+//constants used(Table A-3)
+cw=4.18;//in kJ/kg C
+ci=0.45;//in kJ/kg C
+
+//calculations
+Tfk=(mi*ci*Tii+mw*cw*Tiw)/(mw*cw+mi*ci);
+Tfc=Tfk-273;//in C
+disp(Tfc,'the final equilibrium temperature in C');
+X1i=mi*ci*(Tii-T0-T0*log(Tii/T0));
+X1w=mw*cw*(Tiw-T0-T0*log(Tiw/T0));
+X1t=X1i+X1w;//total exergy 
+disp(X1t,'intial exergy of combined systems in kJ');
+X2i=mi*ci*(Tfk-T0-T0*log(Tfk/T0));
+X2w=mw*cw*(Tfk-T0-T0*log(Tfk/T0));
+X2t=X2i+X2w;//total exergy 
+disp(X2t,'intial exergy of combined systems in kJ');
+Xdestroyed=X1t-X2t;
+disp(Xdestroyed,'the wasted work in kJ')
diff --git a/2870/CH8/EX8.14/Ex8_14.sce b/2870/CH8/EX8.14/Ex8_14.sce
new file mode 100755
index 000000000..ae2b4079f
--- /dev/null
+++ b/2870/CH8/EX8.14/Ex8_14.sce
@@ -0,0 +1,24 @@
+clc;clear;
+//Example 8.14
+
+//given data
+TR=1200;
+T0=300;
+P0=100;
+Tsys=400;
+P1=350;
+V1=0.01;
+V2=2*V1;    
+
+//calculations
+W=P1*V1*log(V2/V1);
+Wsurr=P0*(V2-V1);
+Wu=W-Wsurr;
+disp(Wu,'the useful work output in kJ');
+// Qin - W = m*Cv*dT, Since dt=0
+Q=W;
+Sgen=Q/Tsys-Q/TR;
+Xdestroyed=T0*Sgen;
+disp(Xdestroyed,'the exergy destroyed in kJ/K');
+Wrev=T0*Q/Tsys-Wsurr+(1-T0/TR)*Q;
+disp(Wrev,'the reversible work is done in the process in kJ');
diff --git a/2870/CH8/EX8.15/Ex8_15.sce b/2870/CH8/EX8.15/Ex8_15.sce
new file mode 100755
index 000000000..3be0f9208
--- /dev/null
+++ b/2870/CH8/EX8.15/Ex8_15.sce
@@ -0,0 +1,35 @@
+clc;clear;
+//Example 8.15
+//calculation error in textbook in part - b which changes all the following answers
+
+//given data
+m=8;
+T0=25+273;//in K
+P0=100;
+P1=3000;
+T1=450;
+P2=200;
+T2=150;
+Qout=300;
+
+//from Table A-6 and A-4
+h1=3344.9;
+s1=7.0856;
+h2=2769.1;
+s2=7.2810;
+h0=104.83;
+s0=0.3672;
+
+//calculations
+// Ein = Eout
+Wout=m*(h1-h2)-Qout;
+disp(Wout,'the actual power output in kW');
+// Xin = Xout
+Wrev=m*((h1-h2)-T0*(s1-s2));
+disp(Wrev,'the maximum possible work output in kW');
+nII=Wout/Wrev;
+disp(nII,'second law efficiency');
+Xdestroyed=Wrev-Wout;
+disp(Xdestroyed,'the exergy destroyed in kW');
+X1=h1-h0-T0*(s1-s0);
+disp(X1,'the exergy of the steam at inlet conditions in kJ/kg')
diff --git a/2870/CH8/EX8.16/Ex8_16.sce b/2870/CH8/EX8.16/Ex8_16.sce
new file mode 100755
index 000000000..829869c7f
--- /dev/null
+++ b/2870/CH8/EX8.16/Ex8_16.sce
@@ -0,0 +1,27 @@
+clc;clear;
+//Example 18.16
+
+//given data
+T0=70+460;
+T1=50;
+T2=240;
+T3=130;
+//as dicussed in example 7-20
+m1=300;
+m2=22.7;
+m3=322.7;
+
+//from steam tables
+h1=18.07;
+s1=0.03609;
+h2=1162.3;
+s2=1.7406;
+h3=97.99;
+s3=0.18174;
+
+//calculations
+Wrev=m1*(h1-T0*s1)+m2*(h2-T0*s2)-m3*(h3-T0*s3);
+Wrev=round(Wrev);
+disp(Wrev,'the reversible power in Btu/min')
+Xdestroyed=Wrev;
+disp(Xdestroyed,'the rate of exergy destruction in Btu/min')
diff --git a/2870/CH8/EX8.17/Ex8_17.sce b/2870/CH8/EX8.17/Ex8_17.sce
new file mode 100755
index 000000000..70dcfac15
--- /dev/null
+++ b/2870/CH8/EX8.17/Ex8_17.sce
@@ -0,0 +1,20 @@
+clc;clear;
+//Example 8.17
+
+//given data
+V=200;
+P1=100;
+P2=1000;
+P0=100;
+T=300;
+
+//constants used
+R=0.287;//in kPa m^3/kg K
+
+//calculations
+//Xin - Xout = Xdestroyed = X2 - X1
+m2=P2*V/(R*T);
+X2=R*T*(log(P2/P0)+P0/P2-1);
+Wrev=m2*X2/1000;
+Wrev=round(Wrev);
+disp(Wrev,'Work requirement in MJ')
diff --git a/2870/CH8/EX8.2/Ex8_2.sce b/2870/CH8/EX8.2/Ex8_2.sce
new file mode 100755
index 000000000..b736c74cb
--- /dev/null
+++ b/2870/CH8/EX8.2/Ex8_2.sce
@@ -0,0 +1,13 @@
+clc;clear;
+//Example 8.2
+
+//given values
+TH=2000;
+T0=77+460;//in R
+Qin=3000;
+
+//calculation
+nth=1-(T0/TH);
+Wmax=nth*Qin;
+Wmax=round(Wmax)
+disp(Wmax,'the rate of energy flow in Btu/s')
diff --git a/2870/CH8/EX8.3/Ex8_3.sce b/2870/CH8/EX8.3/Ex8_3.sce
new file mode 100755
index 000000000..ac37cb14f
--- /dev/null
+++ b/2870/CH8/EX8.3/Ex8_3.sce
@@ -0,0 +1,14 @@
+clc;clear;
+//Example 8.3
+
+//given data
+Tsink=300;
+Tsource=1200;
+Qin=500;
+Wuout=180;
+
+//calculations
+Wrev=(1-Tsink/Tsource)*Qin;
+disp(Wrev,'The reversible power in kW');
+I=Wrev-Wuout;
+disp(I,'the irreversiblity rate in kW')
diff --git a/2870/CH8/EX8.4/Ex8_4.sce b/2870/CH8/EX8.4/Ex8_4.sce
new file mode 100755
index 000000000..6f428e03b
--- /dev/null
+++ b/2870/CH8/EX8.4/Ex8_4.sce
@@ -0,0 +1,18 @@
+clc;clear;
+//Example 8.4
+
+//given data
+m=500;
+T1=473;
+T0=300;
+Wu=0;
+
+//from Table A-3
+cavg=0.45;
+
+//calculations
+Wrev=integrate('(1-T0/T)*(-m*cavg)','T',T1,T0);//intergrant
+Wrev=floor(Wrev);
+disp(Wrev,'The reversible power in kJ');
+I=Wrev-Wu;
+disp(I,'the irreversiblity rate in kJ');
diff --git a/2870/CH8/EX8.5/Ex8_5.sce b/2870/CH8/EX8.5/Ex8_5.sce
new file mode 100755
index 000000000..6efb932ac
--- /dev/null
+++ b/2870/CH8/EX8.5/Ex8_5.sce
@@ -0,0 +1,16 @@
+clc;clear;
+//Example 8.5
+
+//given data
+Wrev=8191;
+Wtotal=38925;
+TL=278;
+TH=300;
+
+//calculations
+Wrm=Wtotal-Wrev;//work remaining
+COPHP=1/(1-TL/TH);
+Wd=COPHP*Wrev;//work delivered
+PS=Wd+Wrm;
+PS=round(PS/1000);//factor of 1000 for converting kJ into MJ
+disp(PS,'Maximum amount of heat in MJ')
diff --git a/2870/CH8/EX8.6/Ex8_6.sce b/2870/CH8/EX8.6/Ex8_6.sce
new file mode 100755
index 000000000..5463ead68
--- /dev/null
+++ b/2870/CH8/EX8.6/Ex8_6.sce
@@ -0,0 +1,12 @@
+clc;clear;
+//Example 8.6
+
+//given data
+COP=1;
+TL=283;//in K
+TH=294;//in K
+
+//calculations
+COPHP=1/(1-TL/TH);
+nII=COP/COPHP;
+disp(nII,'the second law efficiency')
diff --git a/2870/CH8/EX8.7/Ex8_7.sce b/2870/CH8/EX8.7/Ex8_7.sce
new file mode 100755
index 000000000..3b2e0f1ed
--- /dev/null
+++ b/2870/CH8/EX8.7/Ex8_7.sce
@@ -0,0 +1,19 @@
+clc;clear;
+//Example 8.7
+
+//given data
+P1=1000;
+V=200;
+T1=300;
+T0=T1;
+P0=100;
+
+//constants used
+R=0.287;//in kPa m^3/kg K
+
+//calculations
+m1=P1*V/(R*T1);
+O1=R*T0*(P0/P1-1)+R*T0*log(P1/P0);// O refers to exergy
+X1=m1*O1/1000;//factor of 1000 for converting kJ into MJ
+X1=round(X1);
+disp(X1,'work obtained in MJ')
diff --git a/2870/CH8/EX8.8/Ex8_8.sce b/2870/CH8/EX8.8/Ex8_8.sce
new file mode 100755
index 000000000..3a69d0ee7
--- /dev/null
+++ b/2870/CH8/EX8.8/Ex8_8.sce
@@ -0,0 +1,22 @@
+clc;clear;
+//Example 8.8
+
+//given data
+T0=20+273;//in K
+P1=0.14;
+T1=-10;
+P2=0.8;
+T2=50;
+
+//the properties of refrigerant
+//at inlet
+h1=246.36;
+s1=0.9724;
+//at outlet
+h2=286.69;
+s2=0.9802;
+dO=h2-h1-T0*(s2-s1);// O refers to exergy
+dO=round(dO);
+disp(dO,'the exergy change of the refrigerant in kJ/kg')
+wmin=dO;
+disp(wmin,'the minimum work input that needs to be supplied is in kJ/kg')