6 files changed, 97 insertions, 0 deletions
diff --git a/3878/CH21/EX21.1/Ex21_1.sce b/3878/CH21/EX21.1/Ex21_1.sce
new file mode 100644
index 000000000..591c97dbd
--- /dev/null
+++ b/3878/CH21/EX21.1/Ex21_1.sce
@@ -0,0 +1,15 @@
+clear
+// Variable declaration
+m_a=68// The mass flow rate of air in kg/s
+T_1=16// The temperature of air at inlet in °C
+T_2=34// The temperature of air at outlet in °C
+T_win=85// The temperature of hot water at inlet in °C
+T_wout=74// The temperature of hot water at outlet in °C
+C_pa=1.02// The specific heat capacity of air in kJ/kg.K
+C_pw=4.187// The specific heat capacity of water in kJ/kg.K
+
+// Calculation
+Q=m_a*C_pa*(T_2-T_1)// Heat input in kW
+m_w=Q/(C_pw*(T_win-T_wout))// The mass flow rate of water in kg/s
+printf("\n \nHeat input,Q=%4.0f kW \nThe mass flow rate of water,Q=%2.0f kg/s",Q,m_w)
+
diff --git a/3878/CH21/EX21.10/Ex21_10.sce b/3878/CH21/EX21.10/Ex21_10.sce
new file mode 100644
index 000000000..12809173a
--- /dev/null
+++ b/3878/CH21/EX21.10/Ex21_10.sce
@@ -0,0 +1,13 @@
+clear
+// Variable declaration
+T_d=23// The dry bulb temperature in °C
+H=40// % saturation
+SH=36// The sensible heat to be removed in kW
+LH=14// The latent heat in kW
+
+// Calculation
+// Plotting on the chart ( Figure 21.10 ) from 23°C/40% and using the ratio
+R=SH/(SH+LH)
+printf("\n The process line meets the saturation curve at - 1°C, giving the ADP (which meansthat condensate will collect on the fins as frost).")
+
+printf("\n Taking the condition at 5°C dry bulb and measuring the proportion along theprocess line gives a coil contact factor of 75")
diff --git a/3878/CH21/EX21.2/Ex21_2.sce b/3878/CH21/EX21.2/Ex21_2.sce
new file mode 100644
index 000000000..67587f834
--- /dev/null
+++ b/3878/CH21/EX21.2/Ex21_2.sce
@@ -0,0 +1,11 @@
+clear
+// Variable declaration
+Q=500// The amount of heat required for the building in kW
+T=19// The temperature at which air enters the heater coil in °C
+m_a=68// // The mass flow rate of air in kg/s
+C_pa=1.02// The specific heat capacity of air in kJ/kg.K
+
+// Calculation
+t=T+(Q/(m_a*C_pa))// The air supply temperature in °C
+printf("\n The air-supply temperature,t=%2.1f°C",t)
+
diff --git a/3878/CH21/EX21.3/Ex21_3.sce b/3878/CH21/EX21.3/Ex21_3.sce
new file mode 100644
index 000000000..af36e332b
--- /dev/null
+++ b/3878/CH21/EX21.3/Ex21_3.sce
@@ -0,0 +1,24 @@
+clear
+// Variable declaration
+T_ra=21// The temperature of the returning air 
+H=50// % saturation
+T_d=28// The dry bulb temperature in °C
+T_w=20// The wet bulb temperature in °C
+m_a=20// The mass flow rate of returning air in kg/s
+m_b=3// The mass flow rate of outside air in kg/s
+x_ra=0.0079// The moisture content in kg/kg
+x_oa=0.0111// The moisture content in kg/kg
+h_a=41.8// The enthalpy in kJ/kg
+h_b=56.6// The enthalpy in kJ/kg
+
+// Calculation
+// Method (b)
+t_c=((T_ra*m_a)+(T_d*m_b))/(m_a+m_b)// °C
+g_c=((x_ra*m_a)+(x_oa*m_b))/(m_a+m_b)// kg/kg
+h_c=((h_a*m_a)+(h_a*m_b))/(m_a+m_b)// kJ/kg dry air
+printf("\n \nThe condition of the mixture,t_c=%2.1f°C",t_c)
+
+printf("\n \n  g_c=%0.4f kg/kg",g_c)
+
+printf("\n \n  h_c=%2.1f kJ/kg dry air",h_c)
+
diff --git a/3878/CH21/EX21.6/Ex21_6.sce b/3878/CH21/EX21.6/Ex21_6.sce
new file mode 100644
index 000000000..ca8b71e25
--- /dev/null
+++ b/3878/CH21/EX21.6/Ex21_6.sce
@@ -0,0 +1,18 @@
+clear
+// Variable declaration
+T_d1=23// The dry bulb temperature in °C
+T_w=5// The temperature of water in °C
+H=50//  % saturation
+n_s=0.7// Saturation efficiency in %
+x_a=0.0089// Moisture content in kg/kg
+x_b=0.0054// Moisture content in kg/kg
+
+// Calculation
+//(a)
+printf("\n (a) By construction on the chart ( Figure 21.7 ), the final condition is 10.4°C dry bulb,82 percents saturation")
+
+//(b)
+T_d2=T_d1-(n_s*(T_d1-T_w))// The final dry bulb temperature in °C
+x_f=x_a-(n_s*(x_a-x_b))// kg/kg
+printf("\n \n(b)The final condition,\n   The final dry bulb temperature=%2.1f°C \n   The moisture content=%0.5f kg/kg",T_d2,x_f)
+
diff --git a/3878/CH21/EX21.8/Ex21_8.sce b/3878/CH21/EX21.8/Ex21_8.sce
new file mode 100644
index 000000000..9b09eb799
--- /dev/null
+++ b/3878/CH21/EX21.8/Ex21_8.sce
@@ -0,0 +1,16 @@
+clear
+// Variable declaration
+T_d1=24// The dry bulb temperature in °C
+T_d2=7// The dry bulb temperature in °C
+H=45//  % saturation
+cf=0.78// Contact factor
+h_1=45.85// The enthalpy in kJ/kg
+h_2=22.72// The enthalpy in kJ/kg
+
+// Calculation
+//(a) By construction on the chart ( Figure 21.9 ), 10.7°C dry bulb, 85% saturation.
+//(b) By calculation, the dry bulb will drop 78% of 24 to 7°C:
+dT=T_d1-(cf*(T_d1-T_d2))// The drop in dry bulb temperature in °C
+dh=h_1-(cf*(h_1-h_2))// The drop in enthalpy in kJ/kg
+printf("\n \nThe drop in dry bulb temperature=%2.1f°C \nThe drop in enthlpy=%2.2f kJ/kg",dT,dh)
+