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-rw-r--r--3733/CH18/EX18.1/Ex18_1.sce25
-rw-r--r--3733/CH18/EX18.2/Ex18_2.sce35
-rw-r--r--3733/CH18/EX18.3/Ex18_3.sce31
-rw-r--r--3733/CH18/EX18.4/Ex18_4.sce15
4 files changed, 106 insertions, 0 deletions
diff --git a/3733/CH18/EX18.1/Ex18_1.sce b/3733/CH18/EX18.1/Ex18_1.sce
new file mode 100644
index 000000000..41235ca4c
--- /dev/null
+++ b/3733/CH18/EX18.1/Ex18_1.sce
@@ -0,0 +1,25 @@
+// Example 18_1
+clc;funcprot(0);
+//Given data
+n=10;// Number of fans used
+T_1=35;// °C
+T_2=30;// °C
+m_w1=1000;// The quantity of cooling tower circulated through the tower in kg/min
+DBT=35;// Dry bulb temperature in °C
+WBT=25;//Wet bulb temperature in °C
+C_pw=4.2;// kJ/kg°C
+RH=90;// Relative humidity in %
+
+//Calculation
+//The conditions of air at inlet and outlet are represented on psychrometric chart as shown in Fig.Prob.18.1(b)
+// From psychrometric chart,
+H_a1=76.4;// kJ/kg
+H_a2=94.5;// kJ/kg
+w_1=19;// grams/kg
+w_2=24.4;// grams/kg
+v_s1=0.895;// m^3/kg
+V=(v_s1*m_w1*C_pw*(T_1-T_2))/((H_a2-H_a1)-(((w_2-w_1)/1000)*C_pw*T_2));// m^3/min
+C=V/n;// Capacity of each fan in m^3/min
+m_m=(V/v_s1)*((w_2-w_1)/1000)*60;// The quantity of make up in kg/hr
+printf('\nThe quantity of air handled=%0.1f m^3/min \nThe quantity of make up water=%0.0f kg/hr',C,m_m);
+// The answers provided in the textbook is wrong
diff --git a/3733/CH18/EX18.2/Ex18_2.sce b/3733/CH18/EX18.2/Ex18_2.sce
new file mode 100644
index 000000000..05b986b66
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+++ b/3733/CH18/EX18.2/Ex18_2.sce
@@ -0,0 +1,35 @@
+// Example 18_2
+clc;funcprot(0);
+//Given data
+m_w1=400;// Quantity of cooling water in kg/min
+T_1=43.5;// The temperature of water at inlet in °C
+T_a1=18.5;// °C
+RH=60;// Relative humidity in %
+T_a2=27;// °C
+V=600;// Volume of air per minute in m^3/min
+P=4;// Power absorbed in kW
+C_pw=4.2;// kJ/kg°C
+
+//Calculation
+//The conditions of air at inlet and outlet are represented on psychrometric chart as shown in Fig.Prob.18.2
+// Total heat of air at inlet + Total heat of water at inlet + heat dissipatedby motor = Total heat of air at outlet + Total heat of water at outlet
+// From psychrometric chart,
+H_a1=38.87;// kJ/kg
+H_a2=84.85;// kJ/kg
+w_1=7.8;// grams/kg
+w_2=22.6;// grams/kg
+v_s1=0.836;// m^3/kg
+m_a=V/v_s1;// kg/min
+Q=P*60;// kJ/min
+//T_2=y(1)
+function[X]=Temperature(y);
+ X(1)=((m_w1*C_pw*(T_1-y(1)))+Q)-(m_a*((H_a2-H_a1)-(((w_2-w_1)/1000)*C_pw*y(1))));
+endfunction
+y=[10]
+z=fsolve(y,Temperature);
+T_2=z(1);// The temperature of water coming out of the tower in °C
+m_m=m_a*((w_2-w_1)/1000);// The make up water required per hour in kg/min
+printf('\nThe temperature of water coming out of the tower=%0.2f°C \nThe make up water required per hour=%0.1f kg/min',T_2,m_m);
+// The answers provided in the textbook is wrong
+
+
diff --git a/3733/CH18/EX18.3/Ex18_3.sce b/3733/CH18/EX18.3/Ex18_3.sce
new file mode 100644
index 000000000..6b80cccd7
--- /dev/null
+++ b/3733/CH18/EX18.3/Ex18_3.sce
@@ -0,0 +1,31 @@
+// Example 18_3
+clc;funcprot(0);
+//Given data
+T_1=45;//The temperature of water at inlet in °C
+m_w1=360;// kg/min
+V=10;// The air circulated in the tower in m^3/sec
+Q=4900;// The amount of heat absorbed by the air in watts
+DBT=20;// Dry bulb temperature in °C
+RH=60;// Relative humidity in %
+T_a2=26;// The temperature of air leaves the tower at saturated condition in °C
+C_pw=4.2;// kJ/kg°C
+
+//Calculation
+// The condtions of air entering and leaving the tower are represented onn psychrometric chart as shown in Fig.Prob.18.3
+// From psychrometric chart,
+H_a1=45;// kJ/kg
+H_a2=81;// kJ/kg
+w_1=9.6;// grams/kg
+w_2=21.6;// grams/kg
+v_s1=0.848;// m^3/kg
+m_a=V/v_s1;// kg/sec
+Q=Q/1000;// kW=kJ/sec
+//T_2=y(1)
+function[X]=Temperature(y);
+ X(1)=(((m_w1*C_pw*(T_1-y(1)))/60)+Q)-(m_a*((H_a2-H_a1)-(((w_2-w_1)/1000)*C_pw*y(1))));
+endfunction
+y=[10]
+z=fsolve(y,Temperature);
+T_2=z(1);// The temperature of water coming out of the tower in °C
+m_m=m_a*((w_2-w_1)/1000);// The make up water required per hour in kg/min
+printf('\nThe temperature of water coming out of the tower=%0.0f°C \nThe make up water required per hour=%0.3f kg/min',T_2,m_m);
diff --git a/3733/CH18/EX18.4/Ex18_4.sce b/3733/CH18/EX18.4/Ex18_4.sce
new file mode 100644
index 000000000..dcf7a3940
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+++ b/3733/CH18/EX18.4/Ex18_4.sce
@@ -0,0 +1,15 @@
+// Example 18_4
+clc;funcprot(0);
+//Given data
+V=5000;//Circulation of cooling water in m^3/hr
+C=3;// Allowable concentration ratio
+Cr=12;// The cooling range in °C
+El=2;// Evaporation losses in %
+Wl=0.2;// Windage losses in %
+
+//Calculation
+E=(El/100)*V;// Evaporation losses in m^3/hr
+W=(Wl/100)*V;// Windage losses in m^3/hr
+B=(E/(C-1))-W;// Blow down rate in m^3/hr
+M=E+W+B;// The make up water in m^3/hr
+printf('\nThe make up water required=%0.0f m^3/hr',M );