diff options
Diffstat (limited to '3843/CH8')
| -rw-r--r-- | 3843/CH8/EX8.1/Ex8_1.sce | 24 | ||||
| -rw-r--r-- | 3843/CH8/EX8.10/Ex8_10.sce | 21 | ||||
| -rw-r--r-- | 3843/CH8/EX8.11/Ex8_11.sce | 23 | ||||
| -rw-r--r-- | 3843/CH8/EX8.12/Ex8_12.sce | 34 | ||||
| -rw-r--r-- | 3843/CH8/EX8.13/Ex8_13.sce | 27 | ||||
| -rw-r--r-- | 3843/CH8/EX8.2/Ex8_2.sce | 25 | ||||
| -rw-r--r-- | 3843/CH8/EX8.3/Ex8_3.sce | 25 | ||||
| -rw-r--r-- | 3843/CH8/EX8.4/Ex8_4.sce | 25 | ||||
| -rw-r--r-- | 3843/CH8/EX8.5/Ex8_5.sce | 32 | ||||
| -rw-r--r-- | 3843/CH8/EX8.6/Ex8_6.sce | 28 | ||||
| -rw-r--r-- | 3843/CH8/EX8.7/Ex8_7.sce | 26 | ||||
| -rw-r--r-- | 3843/CH8/EX8.8/Ex8_8.sce | 42 | ||||
| -rw-r--r-- | 3843/CH8/EX8.9/Ex8_9.sce | 28 |
13 files changed, 360 insertions, 0 deletions
diff --git a/3843/CH8/EX8.1/Ex8_1.sce b/3843/CH8/EX8.1/Ex8_1.sce new file mode 100644 index 000000000..cb8ce770a --- /dev/null +++ b/3843/CH8/EX8.1/Ex8_1.sce @@ -0,0 +1,24 @@ +// Example 8_1
+clc;funcprot(0);
+// Given data
+P_1=10;// kPa
+P_2=2000;// kPa
+T_3=400;// °C
+h_f=191.8;// kJ/kg
+h_1=h_f;// kJ/kg
+h_3=3248;// kJ/kg
+s_3=7.1279;// kJ/kg.K
+
+// Calculation
+v_1=0.001;// m^3/kg
+w_P=v_1*(P_2-P_1);// The pump work in kJ/kg
+h_2=h_1+w_P;// kJ/kg
+q_B=h_3-h_2;// The heat input in kJ/kg
+s_4=s_3;// kJ/kg.K
+x_4=0.8636;// The quality of steam at state 4
+h_f4=h_f;// kJ/kg
+h_fg4=2393;// kJ/kg
+h_4=h_f4+(x_4*h_fg4);// kJ/kg
+w_T=h_3-h_4;// kJ/kg
+n=(w_T-w_P)/q_B;// The cycle efficiency
+printf("\nThe maximum possible efficiency from the power cycle,n=%0.4f or %2.2f percentage.",n,n*100);
diff --git a/3843/CH8/EX8.10/Ex8_10.sce b/3843/CH8/EX8.10/Ex8_10.sce new file mode 100644 index 000000000..7e2cd1c71 --- /dev/null +++ b/3843/CH8/EX8.10/Ex8_10.sce @@ -0,0 +1,21 @@ +// Example 8_10
+clc;funcprot(0);
+// Given data
+T_1=-20;// °C
+T_3=41.64;// °C
+mdot=0.6;// kg/s
+
+// Calculation
+h_1=178.6;// kJ/kg
+h_4=76.3;// kJ/kg
+h_3=h_4;// kJ/kg
+s_1=0.7082;// kJ/kg.K
+s_2=s_1;// kJ/kg.K
+h_2=(((0.7082-0.7021)/(0.7254-0.7021))*(217.8-210.2))+210.2;// kJ/kg
+Q_E=mdot*(h_1-h_4);// The rate of refrigeration in kW
+W_C=mdot*(h_2-h_1);// The power needed to operate the compressor in kW
+COP=Q_E/W_C;// The coefficient of performance
+printf("\nThe rate of refrigeration,Q_E=%2.1f kW \nThe coefficient of performance,COP=%1.2f",Q_E,COP);
+Hp=(W_C/0.746)/(Q_E/3.52);// The rating in Hp/ton
+COP=(h_2-h_3)/(h_2-h_1);// The coefficient of performance
+printf("\nThe rating in Hp/ton=%1.2f \nThe coefficient of performance if the cycle is operated as a heat pump,COP=%1.2f",Hp,COP);
diff --git a/3843/CH8/EX8.11/Ex8_11.sce b/3843/CH8/EX8.11/Ex8_11.sce new file mode 100644 index 000000000..65dabffea --- /dev/null +++ b/3843/CH8/EX8.11/Ex8_11.sce @@ -0,0 +1,23 @@ +// Example 8_11
+clc;funcprot(0);
+// Given data
+T_1=-10;// °C
+T_3=40;// °C
+P_1=0.15;// MPa
+n_c=0.80;// The efficiency of the compressor
+mdot=0.6;// kg/s
+
+// Calculation
+// From appendix D we find,using T_3=40°C
+h_4=74.5;// kJ/kg
+h_3=h_4;// kJ/kg
+// From table D-3 at P_1=0.15 MPa and T_1=10°C
+h_1=185;// kJ/kg
+s_1=0.732;// kJ/kg.K
+s_2a=s_1;// kJ/kg.K
+P_2=1.0;// MPa
+h_2a=(((0.732-0.7254)/(0.7476-0.7254))*(225.3-217.8))+218;// kJ/kg
+h_2=((h_2a-h_1)/n_c)+h_1;// kJ/kg
+Q_E=mdot*(h_1-h_4);// The rate of refrigeration in kW
+COP=Q_E/(mdot*(h_2-h_1));// The coefficient of performance
+printf("\nThe rate of refrigeration,Q_E=%2.1f kW \nThe coefficient of performance,COP=%1.2f",Q_E,COP);
diff --git a/3843/CH8/EX8.12/Ex8_12.sce b/3843/CH8/EX8.12/Ex8_12.sce new file mode 100644 index 000000000..aa3bff538 --- /dev/null +++ b/3843/CH8/EX8.12/Ex8_12.sce @@ -0,0 +1,34 @@ +// Example 8_12
+clc;funcprot(0);
+// Given data
+T_1=-20;// °C
+T_3=41.64;// °C
+m_L=0.6;// kg/s
+P_L=151;// kPa
+P_H=1000;// kPa
+
+// Calculation
+P_i=(P_L*P_H)^(1/2);// kPa
+// From appendix D we find,
+h_1=178.6;// kJ/kg
+s_1=0.7082;// kJ/kg.K
+s_2=s_1;// kJ/kg.K
+h_7=76.3;// kJ/kg
+h_8=h_7;// kJ/kg
+h_3=(((389-320)/(400-320))*(43.6-37.1))+37.1;// kJ/kg
+h_4=h_3;// kJ/kg
+s_6=(((389-320)/(400-320))*(0.6928-0.6960))+0.6960;// kJ/kg.K
+s_5=s_6;// kJ/kg.K
+h_5=(((389-320)/(400-320))*(190.97-188.0))+188.0;// kJ/kg
+// At P_i=389 kPa we interpolate and obtain
+// T=10°C s=0.6993 kJ/kg.K h=193.8 kJ/kg
+// T=20°C s=0.7226 kJ/kg.K h=200.3 kJ/kg
+// This gives
+h_2=(((0.7082-0.6993)/(0.7226-0.6993))*(200.3-193.8))+193.8;// kJ/kg
+// Also,extrapolating,we find
+h_6=(((0.6932-0.7021)/(0.7254-0.7021))*(217.8-210.2))+210.2;// kJ/kg
+Q_E=m_L*(h_1-h_4);// kW
+m_H=m_L*((h_2-h_3)/(h_5-h_8));// The mass flux in the high pressure stage in kg/s
+W_in=(m_L*(h_2-h_1))+(m_H*(h_6-h_5));// The power input to the compressors in kW
+COP=Q_E/W_in;// The coefficient of performance
+printf("\nThe rate of refrigeration,Q_E=%2.1f kW \nThe coefficient of performance,COP=%1.2f",Q_E,COP);
diff --git a/3843/CH8/EX8.13/Ex8_13.sce b/3843/CH8/EX8.13/Ex8_13.sce new file mode 100644 index 000000000..3cb81d748 --- /dev/null +++ b/3843/CH8/EX8.13/Ex8_13.sce @@ -0,0 +1,27 @@ +// Example 8_13
+clc;funcprot(0);
+// Given data
+T_1=-10;// °C
+P_3=0.9;// MPa
+Q_C=300;// kW
+C=0.07;// $/kWh
+C_n=0.50;// The cost of operating a furnace in $/therm
+q=100000;// kJ/therm
+
+// Calculation
+// (a)
+// From appendix D we find,
+h_1=183.1;// kJ/kg
+s_1=0.7014;// kJ/kg.K
+s_2=s_1;// kJ/kg.K
+h_3=71.9;// kJ/kg
+h_4=h_3;// kJ/kg
+h_2=(((0.7014-0.6982)/(0.7131-0.6982))*(211.8-204.2))+204.2;// kJ/kg
+mdot=Q_C/(h_2-h_3);// The refrigerant mass flux in kg/s
+W_in=mdot*(h_2-h_1);// The compressor power in kW
+COP=Q_C/W_in;// The coefficient of performance
+// (b)
+Coe=W_in*C;// The cost of electricity in $/h
+// (c)
+Cog=((Q_C*3600)/q)*C_n;// The cost of gas in $/h
+printf("\n(a)The coefficient of performance,COP=%1.2f \n(b)The cost of electricity=$%1.2f/h \n(c)The cost of gas=$%1.2f/h",COP,Coe,Cog);
diff --git a/3843/CH8/EX8.2/Ex8_2.sce b/3843/CH8/EX8.2/Ex8_2.sce new file mode 100644 index 000000000..7d903f3a1 --- /dev/null +++ b/3843/CH8/EX8.2/Ex8_2.sce @@ -0,0 +1,25 @@ +// Example 8_2
+clc;funcprot(0);
+// Given data
+P_1=10;// kPa
+P_2=4;// MPa
+T_3=400;// °C
+h_2=192;// kJ/kg
+h_3=3214;// kJ/kg
+s_3=6.7698;// kJ/kg.K
+
+// Calculation
+s_f4=0.6491;// kJ/kg.K
+s_fg4=7.5019;// kJ/kg.K
+s_4=s_3;// kJ/kg.K
+x_4=(s_4-s_f4)/s_fg4;// The quality of steam at state 4
+q_B=h_3-h_2;// The heat input in kJ/kg
+h_f4=192;// kJ/kg
+h_fg4=2393;// kJ/kg
+h_4=h_f4+(x_4*h_fg4);// kJ/kg
+w_T=h_3-h_4;// kJ/kg
+n_2=w_T/q_B;// The cycle efficiency
+// From example 8.1
+n_1=0.3232;// The power cycle efficiency at P_2=2 MPa
+Pi=((n_2-n_1)/n_1)*100;// The percentage increase in efficiency
+printf(" The percentage increase in efficiency is %1.2f percentage.",Pi);
diff --git a/3843/CH8/EX8.3/Ex8_3.sce b/3843/CH8/EX8.3/Ex8_3.sce new file mode 100644 index 000000000..c3f114169 --- /dev/null +++ b/3843/CH8/EX8.3/Ex8_3.sce @@ -0,0 +1,25 @@ +// Example 8_3
+clc;funcprot(0);
+// Given data
+P_1=10;// kPa
+P_2=2;// MPa
+T_3=600;// °C
+h_2=192;// kJ/kg
+h_3=3690;// kJ/kg
+s_3=7.7032;// kJ/kg.K
+
+// Calculation
+s_f4=0.6491;// kJ/kg.K
+s_fg4=7.5019;// kJ/kg.K
+s_4=s_3;// kJ/kg.K
+x_4=(s_4-s_f4)/s_fg4;// The quality of steam at state 4
+q_B=h_3-h_2;// The heat input in kJ/kg
+h_f4=192;// kJ/kg
+h_fg4=2393;// kJ/kg
+h_4=h_f4+(x_4*h_fg4);// kJ/kg
+w_T=h_3-h_4;// kJ/kg
+n_2=w_T/q_B;// The cycle efficiency
+// From example 8.1
+n_1=0.3232;// The power cycle efficiency at T_3=400°C
+Pi=((n_2-n_1)/n_1)*100;// The percentage increase in efficiency
+printf(" The percentage increase in efficiency is %1.1f percentage.",Pi);
diff --git a/3843/CH8/EX8.4/Ex8_4.sce b/3843/CH8/EX8.4/Ex8_4.sce new file mode 100644 index 000000000..f295b0f6b --- /dev/null +++ b/3843/CH8/EX8.4/Ex8_4.sce @@ -0,0 +1,25 @@ +// Example 8_4
+clc;funcprot(0);
+// Given data
+P_1=4;// kPa
+P_2=2;// MPa
+T_3=400;// °C
+h_2=192;// kJ/kg
+h_3=3248;// kJ/kg
+s_3=7.1279;// kJ/kg.K
+
+// Calculation
+s_f4=0.4225;// kJ/kg.K
+s_fg4=8.0529;// kJ/kg.K
+s_4=s_3;// kJ/kg.K
+x_4=(s_4-s_f4)/s_fg4;// The quality of steam at state 4
+q_B=h_3-h_2;// The heat input in kJ/kg
+h_f4=121;// kJ/kg
+h_fg4=2433;// kJ/kg
+h_4=h_f4+(x_4*h_fg4);// kJ/kg
+w_T=h_3-h_4;// kJ/kg
+n_2=w_T/q_B;// The cycle efficiency
+// From example 8.1
+n_1=0.3232;// The power cycle efficiency at P_1=10 MPa
+Pi=((n_2-n_1)/n_1)*100;// The percentage increase in efficiency
+printf("\nThe percentage increase in efficiency is %1.1f percentage.",Pi);
diff --git a/3843/CH8/EX8.5/Ex8_5.sce b/3843/CH8/EX8.5/Ex8_5.sce new file mode 100644 index 000000000..884b437fb --- /dev/null +++ b/3843/CH8/EX8.5/Ex8_5.sce @@ -0,0 +1,32 @@ +// Example 8_5
+clc;funcprot(0);
+// Given data
+P_3=600;// psia
+T_3=1000;// °F
+P_4=40;// psia
+T_4=600;// °F
+P_5=2;// psia
+
+// Calculation
+// From Table C-2E
+h_2=94;// Btu/lbm
+h_1=h_2;// Btu/lbm
+// From Table C-3E
+h_3=1518;// Btu/lbm
+s_3=1.716;// Btu/lbm-°R
+s_4=s_3;// Btu/lbm-°R
+h_4=(((1.716-1.712)/(1.737-1.712))*(1217-1197))+1197;// Btu/lbm
+// At 40 psuia and 600°F
+h_5=1333;// Btu/lbm
+s_5=1.862;// Btu/lbm-°R
+s_6=s_5;// Btu/lbm-°R
+s_f6=0.175;// Btu/lbm-°R
+s_fg6=1.745;// Btu/lbm-°R
+x_6=(s_6-s_f6)/s_fg6;// The quality of steam at state 6
+h_f6=94;// Btu/lbm
+h_fg6=1022;// Btu/lbm
+h_6=h_f6+(x_6*h_fg6);// Btu/lbm
+q_B=(h_5-h_4)+(h_3-h_2);// The energy input in Btu/lbm
+w_T=(h_5-h_6)+(h_3-h_4);// The energy output in Btu/lbm
+n=w_T/q_B;// The thermal efficiency
+printf("\nThe thermal efficiency,n=%0.3f or %2.1f percentage.",n,n*100);
diff --git a/3843/CH8/EX8.6/Ex8_6.sce b/3843/CH8/EX8.6/Ex8_6.sce new file mode 100644 index 000000000..606d55513 --- /dev/null +++ b/3843/CH8/EX8.6/Ex8_6.sce @@ -0,0 +1,28 @@ +// Example 8_6
+clc;funcprot(0);
+// Given data
+P_1=10;// kPa
+P_2=2;// MPa
+P_5=200;// kPa
+T_3=600;// °C
+h_2=192;// kJ/kg
+h_3=3690;// kJ/kg
+s_3=7.7032;// kJ/kg.K
+
+// Calculation
+// We have from Example 8.3 and the steam tables
+h_1=h_2;// kJ/kg
+h_7=505;// kJ/kg
+h_6=h_7;// kJ/kg
+h_4=2442;// kJ/kg
+h_5=(((7.7032-7.5074)/(7.7094-7.5074))*(2971-2870))+2870;// kJ/kg
+m_6=1;// kg
+m_5=((h_6-h_2)/(h_5-h_2))*m_6;// kg
+m_2=m_6-m_5;// kg
+w_T=(h_3-h_5)+((h_5-h_4)*m_2);// The work output from the turbine in kJ/kg
+q_B=h_3-h_7;// kJ/kg
+n_2=w_T/q_B;// The cycle efficiency
+n_1=0.3568;// The power cycle efficiency from example 8.3
+Pi=((n_2-n_1)/n_1)*100;// The percentage increase in efficiency
+printf(" The percentage increase in efficiency is %1.2f percentage.",Pi);
+
diff --git a/3843/CH8/EX8.7/Ex8_7.sce b/3843/CH8/EX8.7/Ex8_7.sce new file mode 100644 index 000000000..2eb1d6701 --- /dev/null +++ b/3843/CH8/EX8.7/Ex8_7.sce @@ -0,0 +1,26 @@ +// Example 8_7
+clc;funcprot(0);
+// Given data
+P_3=600;// psia
+T_3=1000;// °F
+P_4=40;// psia
+T_4=600;// °F
+P_6=2;// psia
+
+// Calculation
+// We have from Example 8.5 and the steam tables
+h_1=94;// Btu/lbm
+h_2=h_1;// Btu/lbm
+h_8=236;// Btu/lbm
+h_3=1518;// Btu/lbm
+h_7=h_8;// Btu/lbm
+h_5=1333;// Btu/lbm
+h_6=1086;// Btu/lbm
+h_4=1200;// Btu/lbm
+m_6=1;// kg
+m_4=((h_8-h_2)/(h_4-h_2))*m_6;// lbm
+m_2=m_6-m_4;// lbm
+w_T=(h_3-h_4)+((h_5-h_6)*m_2);// The work output from the turbine in Btu/lbm
+q_B=h_3-h_8+((h_5-h_4)*m_2);// Btu/lbm
+n=w_T/q_B;// The efficiency of the reheat-regeneration cycle
+printf("\nThe efficiency of the reheat-regeneration cycle,n=%0.3f or %2.1f percentage.",n,n*100);
diff --git a/3843/CH8/EX8.8/Ex8_8.sce b/3843/CH8/EX8.8/Ex8_8.sce new file mode 100644 index 000000000..c289dbb73 --- /dev/null +++ b/3843/CH8/EX8.8/Ex8_8.sce @@ -0,0 +1,42 @@ +// Example 8_8
+clc;funcprot(0);
+// Given data
+P_1=0.01;// MPa
+P_3=0.2;// MPa
+P_4=4;// MPa
+P_5=30;// MPa
+T_6=600;// °C
+T_8=T_6;// °C
+T_10=350;// °C
+mdot=1;// kg/s
+
+// Calculation
+// The enthalpies are found frrom the steam tables to be
+h_1=192;// kJ/kg
+h_2=h_1;// kJ/kg
+h_4=1087;// kJ/kg
+h_5=h_4;// kJ/kg
+h_8=3674;// kJ/kg
+h_3=505;// kJ/kg
+h_6=3444;// kJ/kg
+h_10=3174;// kJ/kg
+s_6=6.2339;// kJ/kg.K
+s_7=s_6;// kJ/kg.K
+h_7=(((6.2239-6.0709)/(6.3622-6.0709))*(2961-2801))+2801;// kJ/kg
+s_8=7.3696;// kJ/kg.K
+s_9=s_8;// kJ/kg.K
+h_9=(((6.2239-6.0709)/(6.3622-6.0709))*(2961-2801))+2801;// kJ/kg
+s_10=8.0636;// kJ/kg.K
+s_11=s_10;// kJ/kg.K
+s_f11=0.6491;// kJ/kg.K
+s_fg11=7.5019;// kJ/kg.K
+x_11=(s_11-s_f11)/s_fg11;// The quality of steam at state 11
+h_f11=192;// kJ/kg
+h_fg11=2393;// kJ/kg
+h_11=h_f11+(x_11*h_fg11);// kJ/kg
+mdot7=(h_5-h_3)/(h_7-h_3);// kg/s
+mdot9=(((1-mdot7)*h_3)-h_2+(mdot7*h_2))/(h_9-h_2);// kg/s
+W_T=((mdot)*(h_6-h_7))+((1-mdot7)*(h_8-h_9))+((1-mdot7-mdot9)*(h_10-h_11));// The power from the turbine in kW
+Q_B=((mdot)*(h_6-h_5))+((1-mdot7)*(h_8-h_7))+((1-mdot7-mdot9)*(h_10-h_9));// The boiler energy input in kW
+n=W_T/Q_B;// The cycle efficiency
+printf("\nThe maximum possible cycle efficiency,n=%0.3f or %2.1f percentage.",n,n*100);
diff --git a/3843/CH8/EX8.9/Ex8_9.sce b/3843/CH8/EX8.9/Ex8_9.sce new file mode 100644 index 000000000..3b9f40beb --- /dev/null +++ b/3843/CH8/EX8.9/Ex8_9.sce @@ -0,0 +1,28 @@ +// Example 8_9
+clc;funcprot(0);
+// Given data
+P_1=10;// kPa
+P_2=2;// MPa
+T_3=600;// °C
+n_T=80/100;// The efficiency of the turbine
+
+// Calculation
+// From the steam tables we find
+h_2=192;// kJ/kg
+h_1=h_2;// kJ/kg
+h_3=3690;// kJ/kg
+s_3=7.7032;// kJ/kg.K
+s_4a=s_3;// kJ/kg.K
+s_f4a=0.6491;// kJ/kg.K
+s_fg4a=7.5019;// kJ/kg.K
+x_4a=(s_4a-s_f4a)/s_fg4a;// The quality of steam at state 4'
+h_f4a=192;// kJ/kg
+h_fg4a=2393;// kJ/kg
+h_4a=h_f4a+(x_4a*h_fg4a);// kJ/kg
+w_a=n_T*(h_3-h_4a);// kJ/kg
+q_B=h_3-h_2;// kJ/kg
+n=w_a/q_B;// The cycle efficiency
+h_4=h_3-w_a;// kJ/kg
+// The temperature is interpolated to be
+T_4=(((2692-2688)/(2783-2688))*(150-100))+100;// °C
+printf("\nThe cycle efficiency,n=%0.3f or %2.1f percentage. \nThe temperature of steam at tthe turbine outlet,T_4=%3.0f°C",n,n*100,T_4);
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