1 files changed, 25 insertions, 0 deletions
diff --git a/551/CH15/EX15.20/20.sce b/551/CH15/EX15.20/20.sce
new file mode 100755
index 000000000..8053862d7
--- /dev/null
+++ b/551/CH15/EX15.20/20.sce
@@ -0,0 +1,25 @@
+clc
+m_s=800/60; //kg/s
+m_c=m_s;
+m_g=1350/60; //kg/s
+m_h=m_g;
+t_h1=650; //0C
+t_c1=180; //0C
+t_c2=350; //0C
+d=0.03; //m
+L=3; //m
+cph=1; //kJ/kg K
+cpc=2.71; //kJ/kg K
+h_g=250;
+h_s=600;
+
+t_h2=t_h1-(m_c*cpc*(t_c2-t_c1)/cph/m_h);
+U=h_g*h_s/(h_g+h_s);
+Q=m_h*cph*10^3*(t_h1-t_h2);
+theta=((t_h1-t_c2)- (t_h2-t_c1))/log((t_h1-t_c2)/(t_h2-t_c1)); //logarithmic mean temperature difference
+//A=N*%pi*d*L
+
+N=Q/U/theta/(%pi*d*L);
+disp("number of tubes required =")
+disp(N)
+disp("tubes")
+\ No newline at end of file