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Diffstat (limited to '3733/CH17/EX17.11/Ex17_11.sce')
-rw-r--r-- | 3733/CH17/EX17.11/Ex17_11.sce | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/3733/CH17/EX17.11/Ex17_11.sce b/3733/CH17/EX17.11/Ex17_11.sce new file mode 100644 index 000000000..5c5bfb393 --- /dev/null +++ b/3733/CH17/EX17.11/Ex17_11.sce @@ -0,0 +1,33 @@ +// Example 17_11
+clc;funcprot(0);
+//Given data
+m_s=30*10^3;// kg/hr
+x=90/100;// Dryness fraction
+v=1.5;// Water speed in m/s
+d_o=2;// cm
+t=1.2;// mm
+T_wi=15;// °C
+T_wo=25;// °C
+U_o=3000;// W/m^2°C
+P_abs=0.04;//bar
+C_pw=4.2;// kJ/kg.k
+
+//Calculation
+T_s=28.6// The saturation temperature of steam at 0.04 bar in °C
+h_fg=2440;// kJ/kg (from steam tables)
+//Total heat lost by steam power=Total heat gained by water
+m_w=(m_s*h_fg*x)/(C_pw*(T_wo-T_wi));// kg/hour
+Theta_i=T_s-T_wi;// °C
+Theta_o=T_s-T_wo;// °C
+LMTD=(Theta_i-Theta_o)/(log(Theta_i/Theta_o));//Logrithemic mean temperature difference in °C
+A=((m_w*h_fg*x)/3600)/(U_o*LMTD);// m^2
+d_i=(d_o*10)-(2*t);// mm
+T_a=(T_wi+T_wo)/2;
+// For T_a=20°C,
+rho=998.2;// Density in kg/m^3
+n=(m_w/((%pi/4)*(d_i/(10*100))^2*rho*3600));// The number tubes of tubes in one pass
+Tn=2*n;// Total number of tubes in both passes
+L=A/(%pi*(d_o/100)*Tn);// The length of each tube in m
+printf('\nThe surface area required,A=%0.1f m^2\nThe number of tubes in each pass,n=%0.0f\nThe length of each tube,L=%0.2f m',A,n,L);
+// The answer provided in the textbook is wrong
+
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