1 files changed, 158 insertions, 0 deletions
diff --git a/1328/CH12/EX12.4/12_4.sce b/1328/CH12/EX12.4/12_4.sce
new file mode 100644
index 000000000..5e787f4d7
--- /dev/null
+++ b/1328/CH12/EX12.4/12_4.sce
@@ -0,0 +1,158 @@
+printf("\t example 12.4 \n");
+printf("\t approximate values are mentioned in the book \n");
+T1=130; // inlet hot fluid,F
+T2=125; // outlet hot fluid,F
+T3=100; // after sucooling
+t1=80; // inlet cold fluid,F
+t3=100; // outlet cold fluid,F
+W=21000; // lb/hr
+w=167000; // lb/hr
+printf("\t 1.for heat balance \n");
+printf("\t for pentane \n");
+HT1=315; // enthalpy at T1, Btu/lb
+HT2=170; // enthalpy at T2, Btu/lb
+qc=(W*(HT1-HT2)); // for condensation
+printf("\t total heat required for condensing of pentane is : %.2e Btu/hr \n",qc);
+c=0.57; // Btu/(lb)(F)
+qs=((W)*(c)*(T2-T3)); // Btu/hr
+printf("\t total heat required for subcooling of pentane is : %.0e Btu/hr \n",qs);
+Q=qs+qc;
+printf("\t total heat required for  pentane is : %.2e Btu/hr \n",Q);
+printf("\t for water \n");
+c=1; // Btu/(lb)*(F)
+Q=((w)*(c)*(t3-t1)); // Btu/hr
+printf("\t total heat required for water is : %.2e Btu/hr \n",Q);
+deltw=(qc/w);
+printf("\t deltw is : %.1f F \n",deltw);
+t2=t3-deltw;
+printf("\t t2 is : %.1f F \n",t2)
+printf("\t for condensing \n");
+delt1=T2-t2; //F
+delt2=T1-t3; // F
+printf("\t delt1 is : %.0f F \n",delt1);
+printf("\t delt2 is : %.0f F \n",delt2);
+LMTDc=((delt2-delt1)/((2.3)*(log10(delt2/delt1))));
+printf("\t LMTD is :%.1f F \n",LMTDc);
+w1=(qc/LMTDc);
+printf("\t w1 is : %.2e lb/hr \n",w1);
+printf("\t subcooling \n");
+delt3=T3-t1; //F
+delt4=T2-t2; // F
+printf("\t delt1 is : %.0f F \n",delt3);
+printf("\t delt2 is : %.0f F \n",delt4);
+LMTDs=((delt4-delt3)/((2.3)*(log10(delt4/delt3))));
+printf("\t LMTD is :%.1f F \n",LMTDs);
+w2=(qs/LMTDs);
+printf("\t w1 is : %.2e lb/hr \n",w2);
+delt=(Q/(w1+w2));
+printf("\t delt is : % .1f F \n",delt);
+Tc=((T1)+(T2))/(2); // caloric temperature of hot fluid,F
+printf("\t caloric temperature of hot fluid is : %.1f F \n",Tc);
+tc=((t1)+(t3))/(2); // caloric temperature of cold fluid,F
+printf("\t caloric temperature of cold fluid is : %.0f F \n",tc);
+printf("\t hot fluid:shell side,pentane \n");
+printf("\t for condensaton \n");
+Do=0.0625; // ft
+Nt=370; // number of tubes
+G1=(W/(3.14*Nt*Do)); // from eq.12.42
+printf("\t G1 is : %.1e lb/(hr)*(lin ft) \n",G1);
+printf("\t cold fluid:inner tube side,water \n");
+n=4; // number of passes
+L=16; //ft
+at1=0.302; // flow area, in^2
+at=((Nt*at1)/(144*n)); // total area,ft^2,from eq.7.48
+printf("\t flow area is : %.3f ft^2 \n",at);
+Gt=(w/(at)); // mass velocity,lb/(hr)*(ft^2)
+printf("\t mass velocity is : %.1e lb/(hr)*(ft^2) \n",Gt);
+V=(Gt/(3600*62.5));
+printf("\t V is : %.2f fps \n",V);
+mu2=1.98; // at 90F,lb/(ft)*(hr)
+D=0.0517; // ft
+Ret=((D)*(Gt)/mu2); // reynolds number
+printf("\t reynolds number is : %.2e \n",Ret);
+hi=940; //Btu/(hr)*(ft^2)*(F)
+printf("\t hi is : %.0f Btu/(hr)*(ft^2)*(F) \n",hi);
+ID=0.62; // ft
+OD=0.75; //ft
+hio=((hi)*(ID/OD)); // using eq.6.5
+printf("\t Correct hio to the surface at the OD is : %.0f Btu/(hr)*(ft^2)*(F) \n",hio);
+ho=125; // assumption
+tw=(tc)+(((ho)/(hio+ho))*(Tc-tc)); // from eq.5.31
+printf("\t tw is : %.0f F \n",tw);
+tf=(Tc+tw)/(2); // from eq 12.19
+printf("\t tf is : %.0f F \n",tf);
+kf=0.077; // Btu/(hr)*(ft^2)*(F/ft), table 4
+sf=0.6; // from table 6
+muf=0.19; // cp, from fig 14
+ho=120; // Btu/(hr)*(ft^2)*(F), from fig 12.9
+printf("\t Correct ho to the surface at the OD is : %.0f Btu/(hr)*(ft^2)*(F) \n",ho);
+Uc=((hio)*(ho)/(hio+ho)); // clean overall coefficient,Btu/(hr)*(ft^2)*(F)
+printf("\t clean overall coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",Uc);
+Ac=(3040000/(104*36.4));
+printf("\t clean surface required for dcondensation : %.0f ft^2 \n",Ac);
+printf("\t subcooling \n");
+ID=25; // in
+C=0.25; // clearance
+B=12; // baffle spacing,in
+PT=1;
+as=((ID*C*B)/(144*PT)); // flow area,ft^2
+printf("\t flow area is : %.3f ft^2 \n",as);
+Gs=(W/as); // mass velocity,lb/(hr)*(ft^2)
+printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gs);
+mu1=0.46; // at 112.5F,lb/(ft)*(hr), from fig.14
+De=0.95/12; // from fig.28,ft
+Res=((De)*(Gs)/mu1); // reynolds number
+printf("\t reynolds number is : %.2e \n",Res);
+jH=46.5; // from fig.28
+k=0.077; // Btu/(hr)*(ft^2)*(F/ft), from table 4
+Z=1.51; // Z=((c)*(mu1)/k)^(1/3)
+ho=((jH)*(k/De)*(Z)); // using eq.6.15b,Btu/(hr)*(ft^2)*(F)
+printf("\t individual heat transfer coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",ho);
+Us=((hio)*(ho)/(hio+ho)); // clean overall coefficient,Btu/(hr)*(ft^2)*(F)
+printf("\t clean overall coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",Us);
+As=(qs/(Us*LMTDs));
+printf("\t clean surface required for desuperheating : %.1f ft^2 \n",As);
+AC=As+Ac;
+printf("\t total clean surface : %.0f ft^2 \n",AC);
+UC=((Us*As)+(Uc*Ac))/(AC);
+printf("\t weighted clean overall coefficient : %.1f Btu/(hr)*(ft^2)*(F) \n",UC);
+A2=0.1963; // actual surface supplied for each tube,ft^2,from table 10
+A=(Nt*L*A2); // ft^2
+printf("\t total surface area is : %.0f ft^2 \n",A);
+UD=((Q)/((A)*(delt)));
+printf("\t actual design overall coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",UD);
+Rd=((UC-UD)/((UD)*(UC))); // (hr)*(ft^2)*(F)/Btu
+printf("\t actual Rd is : %.4f (hr)*(ft^2)*(F)/Btu \n",Rd);
+printf("\t pressure drop  for annulus \n");
+printf("\t condensation \n");
+Lc=13.4; //ft
+De=0.0792; // fig 28
+f=0.0012; // friction factor for reynolds number 193000, using fig.29
+mu3=0.0165; // at 127.5F
+Ds=2.08; // ft
+phys=1;
+Res1=(De*Gs/mu3);
+printf("\t reynolds number is %.2e \n",Res1);
+rowvap=(72.2/((359)*(590/492)*(14.7/25)));
+printf("\t rowvapour is %.3f ld/ft^3 \n",rowvap);
+s=(rowvap/62.5);
+printf("\t s is %.5f \n",s);
+N=(12*Lc/B)+(1); // number of crosses,using eq.7.43
+printf("\t number of crosses are : %.0f \n",N);
+delPsc=((f*(Gs^2)*(Ds)*(N))/(5.22*(10^10)*(De)*(s)*(phys)))/(2); // using eq.12.47,psi
+printf("\t delPsc is : %.1f psi \n",delPsc);
+printf("\t delPss is negligible \n");
+printf("\t allowable delPa is 2 psi \n");
+printf("\t pressure drop  for inner pipe \n");
+f=0.00022; // friction factor for reynolds number 22500, using fig.26
+s=1;
+phyt=1;
+delPt=((f*(Gt^2)*(L)*(n))/(5.22*(10^10)*(D)*(s)*(phyt))); // using eq.7.45,psi
+printf("\t delPt is : %.1f psi \n",delPt);
+X1=0.1; // X1=((V^2)/(2*g)),using fig.27
+delPr=((4*n*X1)/(s)); // using eq.7.46,psi
+printf("\t delPr is : %.1f psi \n",delPr);
+delPT=delPt+delPr; // using eq.7.47,psi
+printf("\t delPT is : %.1f psi \n",delPT);
+printf("\t allowable delPT is 10 psi \n");
+//end