diff options
Diffstat (limited to '3733/CH14/EX14.4/Ex14_4.sce')
-rw-r--r-- | 3733/CH14/EX14.4/Ex14_4.sce | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/3733/CH14/EX14.4/Ex14_4.sce b/3733/CH14/EX14.4/Ex14_4.sce new file mode 100644 index 000000000..31b564f41 --- /dev/null +++ b/3733/CH14/EX14.4/Ex14_4.sce @@ -0,0 +1,29 @@ +// Example 14_4
+clc;funcprot(0);
+//Given data
+m_g=1250;// The mass flow in the gases in kg/sec
+m_a=1170;//The air flow rate in kg/sec
+T_gi=450;//
+T_go=160;// Temperature of hot gases at inlet and outlet in °C
+T_ai=35;// °C
+d_i=60;// mm
+d_o=65;// mm
+U_o=30;//Over all heat transfer coefficient in W/m^2°C
+V_g=13;// Gas velocity in m/sec
+C_pg=1.1;// kJ/kg-°C
+C_pa=1;// kJ/kg-°C
+R_g=287;// J/kg-K
+p=101.325;// kPa
+
+//Calculation
+v_gi=((R_g/1000)*(T_gi+273))/(p);//Specific volume of gas at entry in m^3/kg
+T_ao=((m_g*C_pg*(T_gi-T_go))/(m_a*C_pa))+T_ai;//°C
+Theta_i=(T_gi-T_ao);// °C
+Theta_o=(T_go-T_ai);// °C
+LMTD_counter=(Theta_i-Theta_o)/(log(Theta_i/Theta_o));//Logrithemic mean temperature difference in °C
+LMTD_actual=LMTD_counter*1.2;// °C
+A=(m_g*C_pg*(T_gi-T_go)*10^3)/(U_o*LMTD_actual);// m^2
+n=m_g/((%pi/4)*(d_i/1000)^2*(V_g/v_gi));// Number of tubes used in air heater
+L=(A/(%pi*(d_o/1000)*n));// meters
+printf('\nThe length,L=%0.0f m \nThe number of tubes used in air heater=%0.0f',L,n);
+// The answer vary due to round off error
|