printf("\t example 16.4 \n"); printf("\t approximate values are mentioned in the book \n"); T1=250; // inlet hot fluid,F T2=100; // outlet hot fluid,F t1=80; // inlet cold fluid,F t2=100; // outlet cold fluid,F W=30000; // lb/hr w=50500; // lb/hr printf("\t 1.for heat balance \n") C=0.225; // Btu/(lb)*(F) Q=((W)*(C)*(T1-T2)); // Btu/hr printf("\t total heat required for oxygwn is : %.2e Btu/hr \n",Q); c=1; // Btu/(lb)*(F) Q=((w)*(c)*(t2-t1)); // Btu/hr printf("\t total heat required for water is : %.2e Btu/hr \n",Q); delt1=T2-t1; //F delt2=T1-t2; // F printf("\t delt1 is : %.0f F \n",delt1); printf("\t delt2 is : %.0f F \n",delt2); LMTD=((delt2-delt1)/((2.3)*(log10(delt2/delt1)))); printf("\t LMTD is :%.1f F \n",LMTD); R=((T1-T2)/(t2-t1)); printf("\t R is : %.1f \n",R); S=((t2-t1)/(T1-t1)); printf("\t S is : %.4f \n",S); printf("\t FT is 0.87 \n"); // from fig 18 delt=(0.87*LMTD); // F printf("\t delt is : %.1f F \n",delt); Tc=(T2+T1)/(2); // caloric temperature of hot fluid,F printf("\t caloric temperature of hot fluid is : %.0f F \n",Tc); tc=((t1)+(t2))/(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,oxygen \n"); ID=19.25; // in, table 11 OD=1; // in, table 11 as=((3.14*ID^2/(4))-(70*3.14*OD^2/(4))-(70*20*0.035*0.5))/(144); printf("\t flow area is : %.2f ft^2 \n",as); p=(70*3.14*(OD))-(70*20*0.035)+(70*20*0.5*2); printf("\t wetted perimeter : %.2e in \n",p); De=(4*as*12/(p)); printf("\t De : %.3f ft \n",De); Gs=(W/as); // mass velocity,lb/(hr)*(ft^2) printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gs); mu1=0.0545; // at 175F,lb/(ft)*(hr), from fig.15 Res=((De)*(Gs)/mu1); // reynolds number printf("\t reynolds number is : %.3e \n",Res); jH=59.5; // from fig.16.10a k=0.0175; Z=0.89; // Z=((c)*(mu1)/k)^(1/3), fig hf=((jH)*(k/De)*(Z)); //using eq.6.15,Btu/(hr)*(ft^2)*(F) printf("\t individual heat transfer coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",hf); Rdo=0.003; hdo=(1/Rdo); hf1=(hdo*hf)/(hdo+hf); // eq 16.37 printf("\t hf1 : %.1f \n",hf1); hfi1=142; // fig 16.9 printf("\t cold fluid:inner tube side,water \n"); at1=0.479; // table 10 L=16; Nt=70; n=4; at=((Nt*at1)/(144*n)); // total area,ft^2,from eq.7.48 printf("\t flow area is : %.4f ft^2 \n",at); D=0.0652; // ft row=62.5; Gt=(w/(at)); // mass velocity,lb/(hr)*(ft^2) printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gt); V=(Gt/(3600*row)); printf("\t V is : %.2f fps \n",V); mu2=1.94; // at 90F,lb/(ft)*(hr) Ret=((D)*(Gt)/mu2); // reynolds number printf("\t reynolds number is : %.2e \n",Ret); hi=(940*0.96); // fig 25 printf("\t hi : %.0f Btu/(hr)*(ft^2)*(F) \n",hi); Rdi=0.003; hdi=(1/Rdi); hi1=(hdi*hi)/(hdi+hi); printf("\t hi1 : %.0f Btu/(hr)*(ft^2)*(F) \n",hi1); UDi=((hfi1)*(hi1)/(hi1+hfi1)); // eq 16.41,Btu/(hr)*(ft^2)*(F) printf("\t overall coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",UDi); A2=0.2048; // 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); UDi1=((Q)/((A)*(delt))); printf("\t design overall coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",UDi1); Re=(1/UDi1)-(1/UDi); printf("\t excess fouling factor : %.5f \n",Re); Ro=9.27; //Adding to the outside fouling factor Rdo1=Rdo+(Re*Ro); printf("\t Rdo : %.4f \n",Rdo1); hf2=(hf/(1+(hf*Rdo1))); printf("\t hf2 : %.1f \n",hf2); hfi2=113; UDi2=((hfi2)*(hi1)/(hi1+hfi2)); // eq 16.41,Btu/(hr)*(ft^2)*(F) printf("\t overall coefficient is : %.1f Btu/(hr)*(ft^2)*(F) \n",UDi2); printf("\t pressure drop for annulus \n"); De1=0.0433; // ft Res1=(De1*Gs/mu1); printf("\t reynolds number : %.2e \n",Res1); f=0.00025; // fig 16.10 s=0.00133; delPs=((f*(Gs^2)*(L))/(5.22*(10^10)*(De1)*(s)*(1))); // using eq.7.44,psi printf("\t delPs is : %.1f psi \n",delPs); printf("\t allowable delPa is 2 psi \n"); printf("\t pressure drop for inner pipe \n"); f=0.00021; // friction factor for reynolds number 29100, using fig.26 s=1; delPt=((f*(Gt^2)*(L)*(n))/(5.22*(10^10)*(0.0625)*(s)*(1))); // using eq.7.45,psi printf("\t delPt is : %.0f psi \n",delPt); printf("\t allowable delPa is 10 psi \n"); //end