printf("\t example 10.3 \n"); printf("\t approximate values are mentioned in the book \n"); T1=250; // inlet hot fluid,F T2=250; // outlet hot fluid,F t1=105; // inlet cold fluid,F t2=130; // outlet cold fluid,F w=50000; // lb/hr W=622; // lb/hr printf("\t 1.for heat balance \n"); printf("\t for gas oil \n"); c=0.47; // Btu/(lb)*(F) Q=((w)*(c)*(t2-t1)); // Btu/hr printf("\t total heat required for gas oil is : %.2e Btu/hr \n",Q); printf("\t for steam \n"); l=945.5; // Btu/(lb) Q=((W)*(l)); // Btu/hr printf("\t total heat required for steam 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); tc=((t1)+(t2))/2; // caloric temperature of cold fluid,F printf("\t caloric temperature of cold fluid is : %.1f F \n",tc); printf("\t hot fluid:shell side,steam \n"); ID=15.25; // in C=0.25; // clearance B=15; // baffle spacing,in PT=1.25; as=((ID*C*B)/(144*PT)); // flow area,ft^2, eq 7.1 printf("\t flow area is : %.3f ft^2 \n",as); Gs=(6220/as); // mass velocity,lb/(hr)*(ft^2), calculation mistake printf("\t mass velocity is : %.2e lb/(hr)*(ft^2) \n",Gs); mu1=0.0314; // at 250F,lb/(ft)*(hr), from fig.15 De=0.060; // from fig.29,ft Res=((De)*(Gs)/mu1); // reynolds number, calculation mistake printf("\t reynolds number is : %.2e \n",Res); ho=1500; //Btu/(hr)*(ft^2)*(F) printf("\t individual heat transfer coefficient is : %.0f Btu/(hr)*(ft^2)*(F) \n",ho); printf("\t cold fluid:inner tube side,crude oil \n"); d1=0.5; // in d2=0.87; // in at1=((3.14*(d2^2-d1^2))/4); printf("\t at1 is : %.1f in^2 \n",at1); Nt=86; n=2; // number of passes L=12; //ft 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); De=(d2^2-d1^2)/(12*d2); printf("\t De is : %.4f ft \n",De); mu2=16.7; // at 117F,lb/(ft)*(hr) Ret=((De)*(Gt)/mu2); // reynolds number printf("\t reynolds number is : %.2e \n",Ret); jH=3.1; // from fig.24 Z=0.35; // Z=(K*(c*mu3/k)^(1/3)),Btu/(hr)(ft^2)(F/ft), at mu3=6.9cp and 28 API Hi=((jH)*(1/De)*(Z)); //Hi=(hi/phyp),using eq.6.15a,Btu/(hr)*(ft^2)*(F) printf("\t Hi is : %.1f Btu/(hr)*(ft^2)*(F) \n",Hi); ID=0.87; // ft OD=1; //ft Hio=((Hi)*(ID/OD)); //Hio=(hio/phyp), using eq.6.5 printf("\t Correct Hi0 to the surface at the OD is : %.1f Btu/(hr)*(ft^2)*(F) \n",Hio); muw=4.84; // lb/(ft)*(hr), from fig.14 phyt=(mu2/muw)^0.14; printf("\t phyt is : %.2f \n",phyt); // from fig.24 hio=(Hio)*(phyt); // from eq.6.37 printf("\t Correct hi0 to the surface at the OD is : %.1f Btu/(hr)*(ft^2)*(F) \n",hio); tw=(tc)+(((ho)/(hio+ho))*(T1-tc)); // from eq.5.31 printf("\t tw is : %.0f F \n",tw); Uc=((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",Uc); A=270; // ft^2 printf("\t total surface area is : %.0f ft^2 \n",A); UD=((Q)/((A)*(LMTD))); 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 : %.3f (hr)*(ft^2)*(F)/Btu \n",Rd); printf("\t pressure drop for annulus \n"); f=0.0016; // friction factor for reynolds number 25300, using fig.29 s=0.00116; // for reynolds number 25300,using fig.6 Ds=15.25/12; // ft phys=1; N=(12*L/B); // number of crosses,using eq.7.43 printf("\t number of crosses are : %.0f \n",N); delPs=((f*(19600^2)*(Ds)*(N))/(5.22*(10^10)*(De)*(s)*(phys)))/(2); // using eq.7.44,psi printf("\t delPs is : %.1f psi \n",delPs); printf("\t pressure drop for inner pipe \n"); dt=(d2-d1)/(12); // ft printf("\t dt is : %.4f ft \n",dt); Ret2=(dt*Gt/mu2); printf("\t Ret2 is : %.0f \n",Ret2); f=0.00066; // friction factor for reynolds number 8220, using fig.26 phyt=1.35; // fig 6 printf("\t phyt is : %.2f \n",phyt); s=0.85; delPt=((f*(420000^2)*(L)*(n))/(5.22*(10^10)*(0.0309)*(s)*(phyt))); // using eq.7.45,psi printf("\t delPt is : %.1f psi \n",delPt); printf("\t delPr is negligible \n"); //end